Settings Overview


The Behringer is an extremely complex piece of gear when viewed for the first time. Learning how to move around in the menu system makes things much easier. Call us for a quick runthrough. Once you have gotten used to the Behringers controls, you will be able to dial in your system with a degree of flexibility and precision you will find amazing. You won't be going back to bass and treble controls. 

The Behringer DCX2496 has one Input which can either be digital into Input A or analog which is input into A and B (left and right). To change the type of input press the Input A button and then the setup button (right of knob) and then parameter down to the bottom where you have a choice of either analog or AES/EBU (digital). Reports are that digital sounds better - distinctly so in some cases. 

The Outputs are analog and we use 2 and 5 as the midbass outputs for left and right and 3 and 6 as the Ribbon outputs for left and right. 

There are 5 pages of menus for the inputs and 8 pages of menus for the outputs. You go to different pages by using the page arrow keys to the left of the round control knob. You go to different fields on the page by pushing the parameter buttons under the page buttons. You change the values of those fields by turning the round knob. 

We recommend you leave the dynamic EQ alone - we have no recommendations on it and dynamics are not in short supply with this system. You have to free the outputs so, for example, changing the high rolloff point of output 2 (left midbass) does not automatically change the low rolloff of output 3 (left Ribbon). The channels will still be linked however so pushing channel 2 (left midbass) will generate a solid green light on that channel and a flashing green light on channel 5 (right midbass). Changing a value on one channel will automatically change it on its linked channel.


You have to make sure the mutes are off. Red lights mean mutes are on so push the mute button and press the cancel button for the appropriate fields input and output. When the red lights are off, you are ready to roll. 

Input A (and B if you are running analog inputs) is reduced in gain by 10dB to keep the output levels compatible with a consumer product input, in this case the Panasonic XR45. You will have to experiment with this to get it right for your system. 

The recommended midbass crossover is a 12dB Butterworth (But 12) at 957Hz and the Ribbon is rolled in with a 6 dB Butterworth (but 6) at 2.11kHz. The rising output of the Ribbon at lower frequencies is the reason for this higher electrical crossover. The acoustic crossover is effectively around 1kHz. 

The midbasses have their gain reduced 3.5dB to match the sensitivity level of the Ribbon. 

Also, there are three filters used. The first boosts the bass output for a total of 5 dB starting at 53Hz. The second takes a bump out at 581Hz and the third takes a bump out at 1.07kHz. 

The phase for the Ribbon has been shifted 50 degrees. 

These filters and settings were determined by testing in our big 23x22 foot room, (35x22 with 10' ceilings when you add in our large openings) and your room will almost certainly differ greatly. You can experiment by turning these filters on and of one at a time or all at the same time. You can also dial in different frequencies and boost and cut levels and hear the results in real time. You can add filters to the point where you run out of processing power. You currently have 26% left which will allow quite a few extra filters to take care of most nasty nodes in your listening room.



The EQ filters are parametric which in practical terms means you can chose the exact frequency at which you want to centre the filter, the exact level you want to boost or cut and pretty much exactly control the bandwidth of the filter with the "Q" control. The other types of filters are simple high and low pass (like bass and treble controls). We'll talk to you about it. 

Experiment but always make good notes on the settings and call us for a live runthrough on the Behringer before you use the system!!!



- minus 10 dB, no EQ or delay on the inputs. 


Low pass -midbasses - (2 and 5)

-3.5 dB page one, input source A 

Page 2 

957Hz But 12 - Filters on right side - high end rolloff. 


Page 3 

- EQ 

Filter 1 53Hz, 5.5 dB, LP, 12dB

Filter 2 581Hz, - 5.1dB BP, Q 2.5

Filter 3 1.07kHz -2.3dB, BP, Q 6.3 

- Dynamic EQ etc off 

High Pass -Ribbons- (Outputs 3 and 6) 

Page 2 

But 6 at 2.11kHz - Filters on left side - low end rolloff. 

No EQ 

Page 7 

Phase normal

Phase 50 degrees. 




DVD 6 Channel 

Front speakers large No subwoofer No other enhancement filters or modes 

The trick with the Panasonic is to make the mains large and turn the subwoofer off. Only then will the XR45 feed full frequency into the main speakers. Otherwise there is a 100Hz rolloff and a beautiful bottom end is lost. 

Quick Fix Guide


By eliminating problems:

Symmetry - keep the reflections from each side of the room even. One hard wall and one soft wall will make it very difficult to achieving great soundstaging. 

Rear reflections - usually it is best to minimize them so either keep the seated listening head away from the rear wall or apply considerable acoustic damping to the wall. 

Space - get the speakers out into the room for depth of soundstage. 

Sub Placement - this is critical to the proper integration of the system. As with all of the above considerations, EXPERIMENT AGGRESSIVELY. 

Having problems? - Call us  or email  a sketch of your room see the Room Planner. Look over our Room Set-ups page to get an idea of the issues involved.

Break-In Process

The break-in experience varies widely. Some owners report the speakers sound great out of the box and they did not hear significant differences over time. Others found harshness and restricted bottom end to be very distinct. 

Most owners find that the speakers become noticibly smoother after 3 or 4 days of moderate volume playing time. Most of the benefits of break-in are to be had in the first 3 weeks but reports vary. 

There are however, some clearly defined effects on break-in time. The longer the speakers are played and the louder they are played will determine their break-in status. Eventually, the changes slow down and cease to be audible. Loudspeakers are mechanical devices so not only will time and energy be factors but so will heat and humidity. If you are using a new amplifier, CD player or cables their performance will be changing as well. 

The fastest way to break-in the speakers is to leave them on at moderately high levels when the house is empty. This might not be recommended for owners with tube amps but for conventional solid state gear, there are not likely to be heat or instability issues which will harm the amps or the speakers 

You hear differently from day to day depending on atmospheric changes and the condition of your sinuses. As you become accustomed to the speakers and the system, you stop listening to them and listen through to the music. 

When the time comes that you only hear music when you turn the system on, the speakers are broken in, your electronics are broken in and your ears have determined that they really do like what they are hearing. 

Our new Coaxial Ribbon LineSource designs come in at higher price levels than we have occupied before but they offer significant improvements in both fidelity and practicality over most loudspeakers, regardless of price- conventional or planar - in most listening rooms. They are just as electronics friendly as our other speakers and thus, for $15,000 total system cost, it is possible to attain ultra system performance. Breakin will be the same for the LSRs as any of our loudspeakers but the midbass will be smoother from the start due to reduced room modes and therefore, breaking of the midbasses will be more difficult to detect. 

Unpacking and Setting Up





Open up the top and take out the top packaging. Needle nose pliers to pull the staples and a knife for the tape will make this easy.




Take out the top packaging. Place the carton gently on its side and open the bottom. Make sure flaps are spread out and raise the carton to an upright position. 





 Lift off the main carton and pull out the corner posts and take the cabinet out of the inner carton. 






Lay the cabinet on its back on the Ethafoam pad and line up the predrilled holes with those on the bases. Use a Phillips bit to  tightly fasten the bases to the cabinet bottoms. 

Note that the base must be attached securely to the bottom of the cabinet before the tall, heavy Ribbon is mounted, otherwise the system will be unstable.



Screw in spikes (if required) after the final location in the room is determined. Note that the inserts on the bottom of the bases are not flush so they will scratch a hard floor surface. Keep the speakers on pieces of carpet when moving them on hard surfaces. 

Need to spike on a hard surface? Look at



 Cut the tape around the seams of the carton. 




Open the hinged (R30) lid. In the case of R45, the top comes off completely.



 The Ribbon carton holds 2 ribbons in the case of the R30 and one in the case of the R45. The ribbons are heavy and slippery. Hold them firmly from the back and the bottom and avoid putting pressure on the front screens.




The hardware is all in one Ribbon carton and consists of: 8 spikes (¼" - 20 thread), 8 base mounting screws (1 ½" #10 wood screws), 4 small Ribbon bolts (10-24) and 2 large Ribbon bolts (5/16" - 18) plus 2 Nordost Flatline Gold Ribbon interconnects. 






 Insert the two smaller bolts (10-24 machine screws) in the lower holes and line up with the keyhole slots in the bracket on the mid-bass.








Insert the heads through the slots and then insert the larger bolt through the open slot in the top of the bracket and screw into the Ribbon back. Snug the larger bolt with your fingers but use only light pressure. The lower bolts do not need to be tightened as they are there for alignment. Also, they are tricky to get at due to the binding posts behind them.




Fold the flat conductors of the Nordost cables over each other and slide them into the holes in the 5 way binding posts on the top of the enclosure and tighten the plastic hex nuts with your fingers. Run the cables up to the binding posts on the Ribbon and repeat the procedure. 





Attach your amplifier cables to the binding posts on the rear of the midbass enclosure and you are ready to play music!





Low Waste Packaging!  Please Reuse and Recycle!

The cardboard boxes and the corner posts as well as the bracket tube are recyclable. The Ethafoam packing can be extremely useful for other uses. For instance, the bottom pads given that they are waterproof and insulating make excellent seats at outdoor events. 

The Break-in Procedure 

Breaking the speakers in will result in a smoother sound and greater bass extension and openness. Typically there is a noticeable improvement after 3 or 4 days will full breakin occurring in 3 or 4 weeks. Breakin time is a function of volume and time played.




 If you are 5' 2" tall, this is how you look against the R645.




 If you are biwiring, the top set of binding posts is for the Ribbon and the bottom for the midbass drivers. 




Take the gold grounding straps off if you are biwiring or biamping. Note how they are aligned, as the straps are tricky to get on again.




One of the most popular tweaks is upgrading the capacitor to Hovlands or Thetas type. The new capacitors will be attached directly to the positive Ribbon binding post and the positive lead from the amp. This bypasses the standard Ribbon crossover inside the enclosure. This is an easy tweak to do if you are biwiring. 


Digital Amp Packages


This system is now 6 or 7 years old but for those interested, it can still provide great sound for very few dollars.  If you can't find a Panasonic receiver, a good Onkyo will do nicely.   BTW, virtually all the receivers we've tested from major manufacturers over the $1500 price point have good sounding amplifier sections.   With Onkyo, this seems to start at $600.

Note that some digital amps have crossovers built in like Hypex and Tact.  Several Onkyo receivers have digital crossovers built in like the Onkyo 818 and the new Emotiva pre-processor is supposed to feature crossover capability.  When combined with room correction as in the Onkyo and Emotiva, the results can be superb.  Note however, that crossover settings flexibility varies widely in these components and may not be suitable for your particular speaker system.

The digital output from the CD or DVD player is connected to input A of the Behringer. 

The Behringer crossover then separates the signal into high and low frequencies for both right and left channels. 

Outputs 1, 2 and 3 are for the left channel. Output channel two feeds the midbass (up to 1kHz) and channel 3 feeds the Ribbon (1kHz and above). 

Outputs 4, 5 and 6 are the right channel outputs. Output 4 feeds the midbass and 6 the Ribbon. 

Outputs 1 and 4 are not used in our system. They could be used in the future if we wanted to incorporate a subwoofer into the design making it a 3 way. 

The Behringer crossover feeds the Panasonic receiver which is used strictly for its amplifiers. The input is the 6 channel DVD analog inputs which allows us to use 4 of the 6 inputs. The front channel inputs (left and right) are used for the midbasses and the surround inputs are used for the Ribbons. The Panasonic must be set to DVD 6 channel mode via the button beside the power button on the remote. 

The Volume control on this system is the remote control for the Panasonic. 

You could use the Behringer input and output level controls as well but these should be set and left once the proper level for your room has been arrived at. 

If you are using a preamplifier, the analog outs (left and right) would be plugged into the Behringer inputs A and B. The setup of the Behringer will have to be changed so the input A is analog rather than our setting of digital (AES/EBU). 

Note that the Panasonic receiver is being used only for its amplifiers. It becomes a "dumb" power amp. Once set up in this configuration, you can’t plug other inputs into it or run surround speakers from it. The Panasonic must be driven by the Behringer only. 












Audio System Setup


The proper scale of the music soundstage is an important part of creating a realistic sense of "being there". Looking up at a large beautiful high def image on the video screen begins to seem unnatural after a while if you are listening down to a knee high musical soundstage. 

Match the scale of the soundstage to the visual image!  Tall LineSource speakers will produce the full height perspective of the original event.


Their time has come. Front projectors are making huge strides in their image quality and along with LED, LCD and plasma TVs, have removed the big box (rear projection or CRT) sticking out from between the speakers.

This development is important to music lovers because a ceiling mounted projector and front screen get rid of that huge mass of vibrating panels and reflective surfaces between the speakers which is a rear projector or CRT TV. In other words, getting rid of the big box in favour of a wall mounted screen will distinctly improve soundstage depth and focus to the benefit of both music and home theater sound.   This also means the big cabinet housing a TV should go as well.


If you are tuning your system for music, get the main speakers as far out ahead of the plane of the scrren as possible to reduce reflections. If you are listening to music with no video, you can experiment with ways to try and neutralize the degrading effects of the screen. Moving the speakers out, or draping a comforter over the TV should improve things.  

Remember, you are not trying to reproduce the sound of a movie theatre in your home because the sound in a movie theatre is vastly inferior to most good high end home systems. Going to a movie may be more fun as an event but technically, the home systems are pulling away from the large theaters.


R630v3, R645v3 (Full Range) Designed to be placed some distance out from the back wall (3’ to 6’) and the side walls (2’ to 4’). All of these distances are relative to the hardness or softness of the room. More air for hard rooms, less for soft. The ample bass output of the R645s allows them to be located far from the walls for maximum depth of stage. The listening position should be between 1 and 1.5 times from the speakers to the distance between the speakers. 

LineSource Monitor 

Exactly the same placement as for the R630s except these will be setup for soundstage only. The bass will come from sub-woofers which will be set up separately. This is the ultimate in flexibility. In small rooms, the LSM may well have enough bottom end for most music applications especially when placed near a wall in corners. 

LineSource Reference 

Our new Coaxial Ribbon LineSource designs come in at higher price levels than we have occupied before but they offer significant improvements in both fidelity and practicality over most loudspeakers, regardless of price- conventional or planar - in most listening rooms. They are just as electronics friendly as our other speakers and thus, for $15,000 total system cost, it is possible to attain ultra system performance. These absolutely must be 2+ feet out from the front wall to avoid a cavity effect - trapping side radiation against the front wall. 

Being modular and totally scalable, ceiling height is the only limitation. If you have a big room with a tall ceiling, these will likely light it up better for you than any loudspeaker system on the planet. 


The subs should provide solid bass to less than 20Hz in room. The key elements in integrating a sub seamlessly are picking the location with the fewest room modes (i.e. smoothest and deepest response at the listening seat) and crossing over low enough (40-60Hz) to avoid muddy mid-bass and localization of the sub. A sophisticated electronic/digital crossover is very valuable in this area either in your processor or in the subwoofer itself. Or, externally in the case of the Behringer DXC2496 or DEQX systems. Experiment with reversing the phase in every different location. This will help eliminate ‘fat mid-bass’ and maintain the speed of the system.   Another very easy and first class solution?  ROOM CORRECTION!  Multiple subs spread around the room will produce smaller room modes, be naturally smoother and make far less work for the room correction system and the amps.


Avoid placing the listener’s head close to a hard rear wall. Reflection from the wall will play havoc with both imaging and bass response. If the listening position must have a wall right behind it, cover the wall with Sonex, a heavy curtain or a tapestry laid over fiberglass or foam acoustic insulation etc. Whatever the method, the listeners ears must not be subject to a strong, direct rear reflection. Don’t place one speaker beside a reflective wall and one with open space to the side. Try to make the acoustic floor plan acoustically symmetrical for both right and left sides. If there is open space on one side try to simulate space on the other with absorbent material on the wall, plants etc. Avoid putting large objects in between the speakers. If a large TV or equipment rack (especially with glass doors is placed between the speakers, try to have the object recessed as far as possible. If the object is close to the same depth plane as the speakers, both horizontal and depth elements of the soundstage will fall short of the speakers potential. 

Don’t make assumptions or expect the speakers to work well just because they are setup roughly the same way they were in a friend’s sound room or the dealers demo room.  Your room is unique. It has different dimensions, furnishings and its boundary walls are made of different materials. 

Once you understand the trade-offs, the key to success is experimentation. Try various positions and listen for the differences on different pieces of music. Even a change of two inches one way or the other can result in dramatic improvements at the listening position. But be careful when moving the speakers, they are tall and heavy! Don’t install the spikes until the best position is found. If you run into problems, call Newform for ideas. With the vast majority of rooms, a 90% setup can be achieved very quickly with the final 10% coming with small tweaks over the break-in period. 

Once you have optimized placement, it will be possible to forget about the loudspeakers and enjoy the music to its fullest. 

Happy Listening! 

See also: The Right Loudspeaker.

Moore’s Law


Motorola announced in January 2001 they have developed a digital audio amplification process, dubbed Symphony, which B&K Components is using in their upcoming DA-2100 amplifier. The DA-2100 will do the Symphony processing in a Digital Signal Processor (DSP) program using Motorola's 56300 DSP family. Motorola plans to integrate Symphony processing into future DSPs, much like Dolby Digital, HDCD, AC3, and other algorithms are integrated now. A vendor need only add output power transistors and an output filter to get a high power and high efficiency digital amplifier.


The first trend to note is the proliferation of high fidelity digital audio amplification techniques and hardware fast enough to implement them. Until recently, digital amplifiers did not have enough distortion free bandwidth for use over the entire 20Hz to 20KHz spectrum and were relegated to subwoofer use only. 

The second trend is the integration of these amplifiers with DSP chips to create the first end-to-end digital audio solution for consumer audio. The audio signal stays entirely in the digital domain up to the speaker inputs. These inexpensive integrated modules and chipsets will allow companies to easily implement designs that have better sound and are cheaper to produce than traditional mixed analog/digital approaches. Let's refer to this type of solution as Advanced Digital Audio (ADA). 

In the next few years ADA is going to be a disruptive force in all segments of the audio industry, from portable MP3 players to high-end home stereos. Moore's law, the doubling of the number of transistors on a given chip every 18 months, will quickly push down prices and improve the sound quality available from consumer audio gear.


Digital amplifiers are a type of switching amplifier. Switching amplifiers rapidly switch the output devices on and off at 100KHz or higher, and then usually low-pass filter to recover the audio portion. Older Pulse Width Modulation (PWM) switching amplifiers, called Class-D, controlled their switching with analog circuits. These designs suffered from poor fidelity and high Radio Frequency Interference (RFI). 

A digital amplifier generates its switching signal using digital logic. Purists would say that digital amplifiers must accept a digital input signal and do all processing in the digital domain. By controlling the switching signal with digital logic, advanced signal processing can be employed to compensate for the switching distortion. Most digital amplifiers avoid the Class-D moniker to distance themselves from analog switching approaches. 

Switching amplifiers have been pursued with interest since they offer higher power amplifiers at a lower cost than traditional class A or A/B amplifiers. Switching amplifiers' output devices are switched entirely on or off. This means that the output transistors do not have to dissipate power that is unused at low volume levels as they do in Class A and AB amplifiers. A Class AB amplifier may be 50% efficient at maximum output power while a switching amplifier can achieve 90% efficiency. The story is better than the specs indicate since at low power levels a digital amplifier could be as much as six times more efficient than Class AB. The increased efficiency allows for amplifiers with smaller power supplies and smaller heatsinks with equivalent output power to non-switched designs. Both of these components are costly and bulky, so shrinking them reduces the size and cost of the whole amplifier. 

Until recently though, they were not suitable for high fidelity applications. In the past few years companies like TacT, Spectron, Sharp, and Bel Canto have released digital amplifiers with sound quality on par with traditional analog amplifiers. In fact, some feel that their fidelity surpasses traditional audio amplifiers. While these digital amplifiers cost upwards of $2,000, they are only the vanguard of the coming revolution. 



The second trend highlighted by Motorola's Symphony announcement is the upcoming ADA phenomenon. In 2001 major semiconductor companies will start to release digital chipsets that can handle every audio processing task including amplification. Currently, only Texas Instruments has their solution available in volume. These chipsets will be inexpensive, especially when compared to the many analog and digital parts they replace. For instance, the Pulsus chips go for $7 to $10. 

This phenomenon is being driven by the rapid convergence of cheap powerful DSPs, advanced digital PWM control theory, accurate psychoacoustic models, pervasive digital audio, MP3, and home theater. Market forces and recent technical advancements are making ADA audio technically possible, cost effective, and in demand. 

Not convinced it's happening? Lets see what some of Motorola's competitors have been shopping for lately: 

JUL 1999, Tripath licenses DPP to STMicroelectronics 

Tripath nonexclusively licensed their digital amplification process for use in commodity markets. In return, the company obtained favorable wafer prices and wafer supply availability. 

27 JUL 1999: Cirrus Logic Acquires AudioLogic; Gains Revolutionary PWM and Low-power Audio Technologies 

AudioLogic has several patents on low power DSP and feedback techniques for digital amplifiers. It appears that AudioLogic's feedback scheme is being incorporated into Cirrus's amplifier. AudioLogic's low power DSP could be useful for portable applications but may not have much bearing on amplifier performance. 

16 MAR 2000: Texas Instruments Acquires Danish Toccata Technology 

Toccata developed the EquiBit PWM ampifier process as used by TacT in their $10,000 Millenium amplifier. TacT has a layman's description of the process and its benefits here. 

02 OCT 2000: Cirrus Logic Expands PWM Technology Portfolio Through Purchase of Patents From B&W Loudspeakers 

Cirrus will introduce 5 amplifier chips using sigma-delta techniques. Four will produce a 110-dB dynamic range, and the highest-power product will have a 120-dB range. 

02 DEC 2000: TI releases 4-chip solution for digital audio. 

TI is the only vendor currently making volume shipments of an ADA solution.  

07 FEB 2001: STMicroelectronics gets exclusive license for Apogee's All-Digital DDX Amplifier Technology 

As you can see, digital amplification techniques have become very popular purchases. Philips, MicroSemi, Linear Technologies, and National Semiconductor are not included here because they seem to be using older analog PWM control techniques and focusing on lower cost car and portable applications. STMico has Apogee's technology but has not announced any high power products yet. 

It is odd that Analog Devices, who has a huge presence in audio codecs and DSP, has not made any announcements about a digital amplification strategy. Their SHARC DSPs are popular in audio products like the Sony TA-E9000 ES, Bose Lifestyle, and Denon AVR3300 home theater boxes. Their digital to analog converters and asynchronous sample rate converts are well respected. Unless they've got something in the labs, perhaps they should snap up Tripath or Korea's Pulsus. Tripath, being a mixed signal design, might prove too hard to put onto a single chip with a SHARC DSP. 



Why are large DSP and digital audio houses scrambling for digital amplification intellectual property? Maybe it's because they need it to compete for a piece of the projected $3 billion dollar market in two years time. 

"PC audio applications represented the largest opportunity in 1998 with nearly half of the $1.55 billion market. According to market research firm Forward Concepts, consumer applications will represent the largest segment by 2003, with a compound annual growth rate of 24 percent and a total available market (TAM) of nearly $1.9 billion. The firm predicts that the overall market, including PC, consumer and professional applications, will represent an opportunity of more than a $3 billion by 2003." 

If PC, consumer, professional, and high fidelity products can all use similar chips then the ADA vendors can target most of the audio market with a only a few chipsets. Can you say "economies of scale?" TI and Crystal already have fixed function cores specifically specifically for digital audio. 

It's heartening to see that the large semiconductor companies feel that high fidelity reproduction is worth pursuing. The variety of digital amplifier techniques is also good news since it will give vendors a choice and allow market forces to weed out low fidelity approaches.


Some audio hobbyists will argue that ADA robs them of the chance to mix and match their favorite speakers and amplifiers. Also, some will undoubtedly prefer to use tube electronics. Perhaps the industry can accommodate these segments while still bringing the unprecedented benefits of ADA to High Fidelity's mainstream. The benefits of ADA in high fidelity include cheaper front-end electronics, higher fidelity input to speakers, and much more speaker design flexibility. 

1. A penny saved.... 

No more sinking money into huge transformers, massive heat sinks, expensive crossover components, multiple chassis & power supplies, or exotic cables. In many high-end loudspeakers the inductors in the bass crossover alone can cost more than the digital audio chips we're talking about here. 

ADA will replace many components of a traditional audio system and allow systems designers to shift budget to speaker drivers. Most designers will agree that using high quality drivers is money well spent. While ADA will be priced like any commodity computer chipset, good speaker drivers will remain high price items. Advanced magnetics, high precision mechanical assembly, limited markets, and hand fabrication will conspire to keep quality driver prices relatively dear. 

Even if ADA only equaled the quality of our current rat's nest of preamps, amps, DAC's, cables, and crossovers, the increased expenditure on drivers alone would improve fidelity at any given system price point. This is only the tip of the iceberg. 

2. Garbage In, Garbage Out 

There's a school of thought that says that a speaker can only sound as good as the electronics feeding it. Replacing the speaker correction DSP, DAC, preamp, amplifer(s), and analog crossovers with a tightly integrated digital solution will provide higher signal fidelity at lower cost. With ADA there is no preamp, no analog parts variance errors, no analog parts drift, no compression in analog crossovers, less loop area for RFI problems, etc. Digital amplifiers are receiving good reviews, and they will only get better as the market focuses its resources. 

Some high enders are so concerned with signal fidelity that they use outboard power supplies like the $1000 PS Audio Power Plant 300. These devices resynthesize an AC waveform from household AC to get a more constant and noise free voltage for sensitive electronics. Some digital amplifiers, like Cirrus's, monitor power supply voltage and take it into account when calculating the output. Yet another $1000 to be spent elsewhere in an ADA system since a $15 chipset will remove the need for the component. 

3. Synergy is the speaker designer's friend. 

Digital audio pioneer Meridian has been producing highly acclaimed active loudspeakers for years. Meridian's designs exploit the advantages of integrating DSP, DAC's, and (analog) power amps into the speakers. There are no exotic drivers or revolutionary amplifiers and yet their systems are some of the highest rated in the industry. 

By performing all signal processing in the digital domain and designing each stage to work in tandem with the next, Meridian is able to extract a high level of performance from the components used. The same chips, amplifiers, and drivers used in more traditional stand-alone equipment would result in a system of lower performance at a higher cost. 

ADA will allow companies without digital hardware expertise to perform similar feats but with digital amplification and at lower costs. Sony experimented with digital input audiophile speaker systems back in 1998, as did Dunlavy Audio at the 2000 Consumer Electronics Show. Dunlavy showed a modified version of their SC-IVa with S/PDIF digital inputs, digital crossovers, and a Spectron 600 Watt PWM amplifier for every driver. 

There are many advantages in designing a multi-amplified system with active crossovers, some of which are listed here. There are extra perks to be gained from implementing some or all of an active system in the digital domain. 

 Digital amps are smaller, provide more power, produce less heat, and at a lower cost than their analog cousins. There's an inefficient driver you really like the sound of? Go ahead and use it. Want to biamplify or triamplify? Do it for the cost of a single analog amp. 

 Broader transducer choices for designers. DSPs can provide transparent EQ and crossover flexibility. Know of a driver with great time domain performance, but it's not completely flat? Flatten its frequency response with the DSP. Doing the same complicated EQ in the analog domain can be tricky. 

 expensive, and degrade sound quality. If ADA becomes pervasive, we may even see new drivers that tradeoff frequency response flatness for low non-linear distortion. 

 Crossovers impossible for analog designs are possible with digital crossovers. You need 4th order crossover slopes, but like the linear phase properties of 1st order designs? With digital FIR filters you can have both. 

 More decor friendly packaging could boost sales. ADA solutions could be designed with less boxes and cabling since there are fewer components. Speaker enclosures can be made more acceptable to consumers. Dedicated high power amplifiers can reduce bass cabinet size, and DSP delayed signals can align drivers' output without unusual baffle designs. Wireless networking such as IEEE-1394 could even remove the need for cables from the audio system to speakers with integral amplifiers. 

 With crossovers determined by coefficients in the DSP code, designers can test many more crossover shapes much faster than before. It's quicker to change coefficients than solder up a new board. Designers could A/B test crossover curves at the press of a button. 

See Meridian's site for additional ideas on digital integration. 

4. Upgradeable & Customizable speakers. 

This could actually create a new trend in the industry. Currently designers spend (we hope) a lot of time measuring and listening to the crossovers before going into production. How many times have we seen a manufacturer release a Mk II, or a factory upgrade to change crossovers in production systems? 

With DSP based crossovers, if a revision is warranted it could be published online and downloaded instantly at no cost to consumer or manufacturer. Perpetual Technologies has already started down this path with downloadable codes for their P-1A speaker correction DSP box. A company could treat the initial release of their speakers as a "beta" release. Hundreds of listeners in the field could then provide their input for the next crossover release. 


Say we go from the 50% efficiency of class AB amplifiers to 90% for our fancy digital PWM amps. We want 500 Watts RMS per channel so we have plenty of headroom. We still need fairly expensive transformers and capacitors for a 550+ Watt linear power supply. 

Can't we use a switch mode power supply (SMPS) for its cheaper, smaller transformer and better regulation under load? Accepted in the mass market and pro audio worlds, switching supplies do not have much presence in the high fidelity segment. It's difficult to suppress switching noise, and switching RFI plays havoc with nearby circuits and wires. Implementing a low noise SMPS requires much more engineering expertise than a quiet linear supply. However, some recent integrated SMPS controller chips have made high quality designs much easier to implement. 

Power semiconductor companies like International Rectifier are producing integrated solutions that incorporate "soft switching" logic such as Zero Voltage Switching (ZVS) and Zero Current Switching (ZCS). Both techniques have better power density, lower RFI, and reduce stress on the switching transistors improving reliability and product lifetimes. Integrated controllers can also provide Power Factor Correction (PFC), reducing AC current demand by 40%. The semiconductor companies are already developing versions of these components tailored for digital audio. 

In September 2000, Cirrus logic and International Rectifier announced they are working together to optimize power supply design, and high power MOSFETS optimized for the PWM output stages of digital amplifiers. Crystal's digital amplifier chipset has a sync-lock to easily integrate with a switching power supply. 

Clearly, the time for switching power supplies in high fidelity amplifiers has come. They have many sound quality advantages over linear supplies if implemented correctly, and can be cheaper. QSC Audio has been using a low EMI resonant switching supply they designed in-house for their acclaimed PowerLight and PLX professional amplifiers for years now. High-fidelity companies will start finding it possible and profitable to move to switching supplies since the new integrated SMPS controllers will lower costs and reduce required design expertise. 

It may already be happening. TacT's high fidelity PWM amp uses a switching supply. The highly regarded model 10 & 12 analog amplifiers from Jeff Rowland use a ZVS/ZCS switching power supply. California Audio Lab's CL-2500 MCA also uses a ZVS design to squeeze 5 x 500 Watt channels into a single chassis. These are all expensive products, but there is no barrier to prevent the technology to trickle down to mid priced units. 

Some advanced SMPS controllers use digital domain PWM control as do the audio amplifiers discussed in this article. After all, a regulated power supply is really just a type of amplifier. Digital amplifier designs may eventually integrate the PWM audio signal generation directly into the SMPS control logic, lowering the component count even further. Such designs would process the incoming AC power directly into the desired output signal without any conversion to DC. With this level of integration, it wouldn't be surprising to see a 300-Watt consumer ADA box for $ 300 or less in the next 5 years. 

The increased demand for advanced SMPS designs is due to demand for higher efficiencies and lower EMI/RFI. New European RFI regulations, longer battery life, efficient motor controllers, and computer & networking equipment are just a few of the driving factors. The worldwide market for integrated SMPS controllers and power semiconductors will grow rapidly in the next few years, and will result in lower costs, better specs, and tighter integration. All consumer audio has to do is sit back and enjoy the ride.


Moore's Law and rapid commoditization will drop the prices of ADA solutions to a point where they will be far cheaper to implement than the traditional DAC, amplifier, and crossover combination. The high-end industry will have an inexpensive solution to every part of the reproduction chain but the speaker drivers and cabinetry. 

So far it looks like Texas Instruments, Motorola, and Cirrus logic are in the lead for high fidelity ADA solutions. Don't count out consumer electronics powerhouses like Sony and Sharp, but their solutions are more likely to be used in-house. Things could get even more interesting if Analog Devices gets on the bandwagon this year. 

To accelerate the acceptance of ADA in the high-end market, some enterprising manufacturer could produce a branded or OEM multi-channel ADA unit for use in digital active speakers. Add some filter design software and half the industry would be knocking on your door. QSC has the right idea with their DSP-3 module and filter design software for their analog amplifiers. 

Speaker design houses could integrate ADA boxes into their designs, or they could be purchased separately by the consumer and the appropriate software downloaded from the speaker manufacturer's website. The convergence of digital audio makes it likely that this type of product will be developed by both amplifier companies and digital audio companies alike since the cost of adding one to the other will be low. 

High end amplifier companies will need to enter the ADA ring as even mid-priced digital power amplifiers will challenge their fidelity. Some high-end companies will probably become nothing more than valued brand names and distribution channels for repackaged OEM amplifier modules. However, when everyone is using the same five amplifier chipsets the problem for companies will be differentiating themselves from the pack. Since high performance will be easier to achieve, manufacturers may try to add value with unique packaging and hardware/software features targeted at niche markets. For instance, ADA boxes with integrated high quality Analog to Digital Converters like might be a selling point for those with large record collections. 

Luckily the coming transition to ADA won't force companies to abandon their current customer base. With the inclusion of an analog to digital converter ADA boxes could be used just like traditional amplifiers. Sharp is doing this with their SM-SX100. Manufacturers will be able to serve different audio market segments with the same electronics. 

Most of the digital amplifier chipset vendors are building products at three power levels. Portable, consumer, and Professional / Audiophile. This is a sensible strategy as the market exists today. However, if the cost and quality of ADA electronics causes the audiophile market to transition to active speakers, there will be reduced demand for high power amplifiers. With multi-amped active speakers, high fidelity companies may end up piggybacking on the midpower mass market segment. 

In multi-amped designs it is common to see every driver's amplifier under 100 Watts. A 30 Watt module, bridged to provide 60 Watts for a driver would satisfy many active driver requirements. With clipping distortion in digital amplifiers mitigated by transparent signal processing, designers will be able to size the system's amplifiers better, and without the risk of expensive warranty repairs for blown drivers. Mid-power mass-market modules could offer the incremental cost savings of high volume parts. 

With the DSP power and programmability of consumer products like Perpetual Tech's P-1A and Sony's TA-E9000 ES, and innovation from pro audio companies like QSC we're already halfway to high quality ADA active speakers. We can't be sure exactly how events will play out, but high fidelity enthusiasts have a lot to look forward to in the years ahead. 

Want to add new information to the pot or just argue a point? Post a message to the discussion group. To get posting rights and sign up for future news bulletins join WaveFront by following the link under the Members box on the upper left of this page. 

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Digital Wave

The next quantum leap in fidelity is now on the horizon. Make yourself familiar with the concept of the direct digital chain. You are going to be hearing a lot about it. In the digital realm, analog middlemen are going to be eliminated to the great benefit of fidelity. There are three levels of audio system sophistication of interest to anyone reading this. 

The first level involves a largely analog signal path which either originates as analog in a turntable or as digital in a CD player and is converted (A to D) to an analog signal. It then goes through interconnects to the pre-amp, is processed and passed through interconnects to the amp where the signal goes through 2 to 4 gain stages and feedback loops emerging as a power signal passing through speaker cables and ends up in the loudspeakers where it passes through passive crossovers consisting of large inductors, capacitors and resistors. A higher level system uses bi-amping and electronic crossovers to replace the passive crossovers for distinctly superior results. 

The third level, and the one that offers a quantum leap in fidelity is now starting to gel. It will take a digital signal right to the loudspeakers where it will be equalized and crossed over in the digital domain and then amplified in digital amplifiers, one for each transducer. The amp output will then travel between 10 and 20 inches along internal speaker wire until it reaches the actual loudspeaker driver. 

In short, no losses, no distortions until the signal is turned into analog power within the digital amp. The digital amp, itself serving as the D to A converter will turn the signal into speaker driving current in a single gain stage as opposed to 2 to 4 gain stages in conventional amps. There are no negative feedback loops. 

The following components and their noise, distortion and phase anomalies are thereby eliminated from the audio signal path: 

D to A converters pre-amps at least 2 sets of interconnects speaker cables passive or active crossovers 1 to 3 amplifier gain stages feed back loops. 

There is a vast improvement in the noise floor and in phase coherency. How important is this? In our own listening sessions and in discussions with others in the industry, it became very clear that the sound improvement is much greater than that achieved by going from 44kHz/16 bit CD to either DVD Audio or SACD. The higher resolution formats are distinctly better but you need a good system, well set up, to really appreciate the improvement. 

The direct digital chain will knock the socks off any listener, experienced or novice (actually, if you compare the direct digital chain with the factory direct concept, there are quite a few similarities). Effective, seamless room equalization may not arrive at the same time as the rest of the digital chain but it is coming as well. 

Upgrading Newform loudspeakers when the time comes will be straight forward and we plan to offer kits for an easy conversion. E-mail for details. A lot of heavy industry types are working on this so look for it to become commonplace in 2 to 3 years. 

The bottom line is, don't spend a great deal of money on amplifiers or pre-amps.


h5 Spectron  

TacT Audio 




Moore's Law Catches up with High Fidelity Audio 


Benefits of Front Projectors


Many of the first video enthusiasts came from the ranks of audiophiles. Equipment and performance driven they expanded their fascination of music reproduction to include the whole home entertainment spectrum. This meant taking a TV and plunking it down in between their carefully placed hifi loudspeakers. 

Of course, it must be noted that many budding videophiles were sufficiently wellheeled to allow them to have a dedicated room for both music and home theater. They didn't even try to achieve great sound in their home theater room because the equipment of the day and the soundtracks were way, way below audiophile standards. 

That part at least has changed. Although still variable, many movie soundtracks now boast excellent acoustics and dare I say it, true hifi sound. And the equipment is now fully on a par with the best from the music 2 channel world. Except, perhaps, a tube surround sound processor is not available. (That's an audiophile joke.) 

Back to dropping a big TV into a carefully tuned music system. In a word: disaster. The soundstage becomes much more two dimensional and both horizontal and depth focus significantly degrade. Also, timbre is slightly to moderately changed. There is no good news here except that when the TV was on it provided enough of a distraction to make the flaws less noticeable. 

Why is a TV an acoustic nightmare? A tube or rear projection TV from an acoustic point of view is a large box consisting of reflective and resonating panels and sharp corners. Instead of the generous space in which the speakers were placed with a wall well behind them, they find themselves roughly on the same plane with this large reflective surface. Effectively now each speaker is in a bit of an alcove. The typical rear projection TV with room for its cabling in the rear, effectively moves the wall forward 2 ½ to 3 feet. That is a big loss of space. Anyone still living with a large TV should place the speakers as far ahead of the plane of the TV as possible. 

Where once the sound radiated out from the speakers in a an uninterrupted hemispheric pattern, the side wave now encounters the TV chassis and reflects both back towards the speaker and forward toward the listener. These delayed waves arrive shortly after the main direct wave from the speaker. This multiple arrival time smears the soundstage focus. 

Because the reflective surfaces of the TV are not 100% solid, they are more reflective for some frequencies than for others. Thin plastic, glass and wood panels are less of an obstacle to low frequencies than they are to high frequencies so they reflect more highs than they do lows. Hence there is a slight tonal imbalance introduced as well. 

Those same thin panels move with the sound that hits them and once moving don't stop once the music does. They now have a (short) life of their own. Tap on any panel of your TV and listen to it's individual sound. This tone is playing (excited by the soundwaves from your main speakers, sub etc.) when your sound system is on and each panel speaks with a different voice. A low level cacophony. TVs are simply not designed with any thought of acoustic performance. 

The British picked up on this early which is why, in a high end British audio shop, there was only one pair of speakers in the room at any one time. If you wanted to listen to another pair, the first were removed and the second brought in. This eliminated the effects of having a set of large boxes upsetting the sound from the working speakers. A large screen RPTV is like having several sets of large speakers at the front of the room. 

The effects are not subtle once you have tried it with and without and you'll be aware the situation is less than ideal until you get rid of the problem. With our own Ribbons, which extend above the top of most RPTVs, standing up will reveal a tremendous depth of soundstage and openness while sitting down the sound stage flattens out and the sound closes up. Very distinct and completely unavoidable even with damping on the sides of the TV cabinet to somewhat reduce the effect. 

Front projectors change all of this. Essentially, they and the screens they project onto are acoustically invisible and return the room to it's state before the arrival of the 3 cubic meters of living surfaces which is a rear projection TV. They give the speakers space and act much the same as the wall behind them. If video screen material is acoustically reflective, it must be at a vanishing level and if the screens resonate (I suppose everything does at some point) it must be imperceptible and probably un-measurable. Video screens suspended several inches off the wall simply get out of the way of the proper and natural sound propagation. 

The bottom line is that front projectors give you your music back. We have long maintained that in the future a great music system will be a great home theater system with the video switched off. Despite an acoustically rough start for home theater, front projectors have now made that ideal an attainable reality for the great majority of music and video enthusiasts.


Changing Face



It may seem that music is being left behind in the rush to cram every conceivable piece of electronic gear, reproducing every format the corporate marketing wizards can conjure up into the "home entertainment room". Certainly music and fidelity have been casualties in the early days of home theater. 

However, the clear trend is back to superb music. This may be happening more by accident than by design but over the next few years, the reproduction of music in the home will be dramatically enhanced by a number of technical advances. 

Number one is the digital chain (link). This is here now in the form of the Tact amps and preamps with DSP crossover and room correction. In combination with excellent drivers and the correct radiation pattern, (digital technology won't correct for everything!) a huge step forward in fidelity is guaranteed for any system. Being in the digital domain, prices can only go down and performance can only go up. With the Tact's superb current level of performance, it is safe to say that although prices will go down dramatically with digital advances, performance will increase in only modest increments. 

Newform had wanted to produce our own system by this time but the delays at the major chip companies plus the arrival of the OEM/DSP crossover capability in the Tact amplifiers has allowed us to go digital now with a level of sophistication we could not have achieved ourselves.  Ditto Onkyo and Emotiva.

The second major breakthrough is the arrival of affordable, high performance front projectors. Many great hifi systems have had their musical potential severely reduced by the addition of large rear projection TVs in between the main loudspeakers. Read "The Acoustic Advantages of Front Projectors" for a more detailed discussion but front projectors restore the acoustics of a hifi only room to pre-RPTV levels. You can now have both superb music reproduction and great video capability in one, no-compromise, system. Upgrade your video capability and get your music back for free. 

Looking at these small, light video projectors, one really has to wonder just what they are going to cost when the factories really crank up production. Ditto digital amps and processors. Future cost may not be precisely definable but the trend is certainly clear. Advances in many areas are converging to make the reproduction of music in the home better, easier and cheaper. High fidelity strikes back! 

Not to be forgotten is the music itself. While media focus has been on the new formats, SACD and DVD audio, the lowly CD has come a long way as well. Recording techniques are improving rapidly and so is our understanding of how to get the most out of the 16 bit, 44kHz format. Up sampling, time correction and buffering are all producing large improvements in sound quality to the point where the higher resolution formats may almost be caught from behind. Not quite maybe but the best CD material will raise a light sweat on the forehead of any of the new formats.


Our buying advice has really not changed in the past 5 years. Due to the imminent arrival of the digital chain, don't spend more than you need to on conventional technology. Since the imminent has actually arrived in the form of the Tact system and affordable front projectors, continue to pick your spots with an eye to the future when buying. It is now possible to clearly see the trend of future developments in both audio and home theater. 

You can take your time and get it right because technology is driving the changes in high fidelity in the right direction. Delays in decision making will result in better available choices when you do decide to commit. Just like buying a computer. By the time you decide to get down off the fence and do something, a faster model will pass you before you can turn the key in the ignition.