Bi-amping B&W 703's

I've got a pair of B&W 703's and a pair of matching Electrocompaniet AW220's.

Currently I'm using the amps in their mono setting one for each speaker.

Not sure if this would work with the crossover, but would there be any advantage in removing the plates that connect the speaker terminals and use one amp in stereo mode for the bass and one in stereo mode for the mid and highs?

Any input would be appreciated.

Absolutely- Your speaker's crossovers are designed with bi-amping or bi-wiring in mind. Bi-amping affords a much greater sonic gain. Just use two pair of identical, high quality cables for the best benefit. A site with some more insights: (
Theoretically monoblock configuration would provide more benefit as each amps power supply is only responsible for producing one speakers bottom octaves- which are the speakers largest demand on the amp.

If you were going to go active, then stereo amps might make sense.
Here's a suggestion: Contact B&W yourself, and ask their opinion. You'll find that they recommend the owner passively bi-amp when the means are available.
There is no right or wrong answer here, try for yourself- however horizontal biamping as you have descirbed has the least chance of being effective.

Vertical biamping (one amp per speaker) or mono moode on your amps is going to most likely work best. The differentiator being how your amps sound in mono mode versus stereo mode.

Keep in in mind that most amps do not have a mono mode which is what throws a twist into your question.

I dont think that horizontal biamping is worth trying, it just doesnt make any sense.

Guess I should not have said mono mode.

The Electrocompaniet amp have a little button at the back that allows you to switch from stereo to mono, but I'm not sure if that's the same as bridging on other amps.

Considering that I'd need more speaker cable I'll probably leave it as is.

That is briding the amps. I would try unbridged stereo operation 1 amp per speaker.

That should yield a nice improvement.

when you say unbridged stereo operation with 1 amp per speaker do you mean using only one channel of each amp per speaker.

When the amps are in the stereo setting I really would need only one amp for the pair of speakers. Maybe I misunderstand what you mean since this doesn't seem to make too much sense.
No- you would use both channels on each amp.

So you have both channels of amp 1 plugged into speaker 1. One channel on the high frequency terminals, the other on the low.

Same thing for speaker 2/ amp 2.

This is called vertical biamping and is typically adventageous because the amps power supply/toroid only needs to drive the low fequency drivers on one speaker.

Just remember to pull the jumpers off each speakers biwire terminals (high freq to low freq bridges) so you dont short out the amp.

Good luck- I really like the way the EC stuff sounds. It seems like a good match for B&W.

Thanks Robr45,

I thought that if only one channel from the preamp goes into an unbridged stereo amp I'd only get an output signal on one side of the amp (basically one side isn't used due to a lack of the signal).

Does that mean I'd have to split the preamp signal and feed it into both sides of the stereo amp?


Yes, you would use a y-adapter on the amp end if your pre does not have two pairs of outputs. I should have mentioned that. Sorry.

Single RCAs come off the pre- terminate into a single female y adapter that splits to dual male RCAs. Repeat on amp/speaker 2.

Radio shack sells decent y adapters. If you like this setup you could spend a little money and get a pair from Audioquest or one of the other better cable manufacturers.
Just spoke to a guy at work who used to work for a TV station and worked a lot on their electronics there.

When I asked him about the y-adapters he was a little concerned about splitting the signal that way since the load would change as well. He suggested to use a little amplifier that has two outputs instead of the y-adapter to keep the signal strength the same.

I'm a mechanical engineer and have always been somewhat at war with electricity (at least my mind has been) and I'd like to find out a little more before I get into this.

Any more suggestions on this issue?

Thanks guys
Ktrauti- Amplifiers with two outputs per channel have an internal circuit that is the same as a Y connector(except perhaps switched). The amplifier would still see the exact same load. Answers like that are probably why that guy isn't working at the TV station any more. The chances of splitting the signal of most pre-amps creating a problem are very slim. There are an awful lot of people out there doing it, as well as recommending it. ( ( ( (
Thanks Rodman99999

I'll read through all the links and will go from there.

Still would like to find out what change there is when splitting the signal in two and what effect it could have on the preamp.

Guess since a lot of people do it it really can't be that harmful. Was wondering if I should contact Electrocompaniet and see what method they would recommend.

Either way, first I'll need cables and need the connectors to split the signal. Hope it'll make an actual change in the sound so I don't waste all the cash on stuff I otherwise don't need.

Still considering a bigger change in the system since the speakers sound too bright to me (guess I'm not alone in this with B&W 703's of what I read here.

Thanks again
The only difference you'll see with the pre-amp is, perhaps, the need to turn the gain up slightly. The output voltage for each channel will be split between the two channels of the respective power amp. Of course: each channel will have twice the power available as well. It couldn't hurt to contact Electrocompaniet. Try aiming the tweeters slightly outboard of your listening position(if they're not already). Is your room hard or soft acoutically?
OOPS- Make that: "acoustically"!
Well, the floor is carpet, the walls are the usual drywall stuff
Furniture is wood and seating is mainly fabric covered.

The wall behind the speakers is actually windows all the way to the ceiling.

The main problem I've always had is that the speakers are somewhat bright sounding, though moving them to the room where they are now and not having a huge projection TV between them has made things better.

When I auditioned them they were driven by a new Classe amp (think it was the CA-2200) and the sound was nice and warm, but the source they used was a lot better then the mediocre Sony Cd player I've got right now.

Guess for now I'll keep playing around a bit before selling the amps and getting something different.

Not sure if tube gear would work well with these speakers but since there's no dealer around here where I could audition any I may just stick to Classe or something that supposedly works well with my speakers.

The other option would still be to get other speakers, but where to start. There's a dealer here in town that has PMC speakers which I've auditioned on Rega components and it was way better for my liking then what I have now. Unfortunately the PMC's cost about twice as much as my speakers and are out of the question right now.

Ok, for now I'll read all the bi-amping stuff and then see which route I'll go.

Thanks guys
Is that an SADC Sony? A lot of people have had them modded to tame a strident top-end. I'm not certain about the other Sony CDP's, but I would upgrade that(or audition something better) before making any other changes. Any kind of curtains between you and those windows? What are you using in the way of interconnects?
Almost 2am and to my embarassment I shall admit that it's a Sony 5 DC changer. Far less then stellar but the Denon player I have has taken a life of it's own and convinced it's components to only read DVD's, CD's are ignored, haha.

Considering that neither the reviews of the Electrocompaniet amps nor the Musical Fidelity A308CR preamp were all that bad the source obviously is one of the things that needs attention. Other than that it's a NAD tuner.

Curtains don't exist and I don't think my lady would have any of them there, neither would I.

Speakr cables and interconnects are from audioquest throughout.

For now I think that the sources are the weakest components in the chain, however, the least pricey thing to change right now will be to change the amp setup and biamp the speakers.

Then get a better source and if that doesn't do it I'll have to take it from there.

Of what I read here it does seem easier to get different speakers that match my amps, after all, the amps aren't that bad I think.

Rodman99999, may I ask what setup you have?

Ok, time to go to bed and rest for a little

My digital source is a BAT VK-D5(6 NOS Siemens CCa's). Analog- a Denon DP-75(custom plinth)/Magnepan Unitrac I/Denon 103D. I'm bi-amping a pair of modded Maggies and some 8' folded, tapered, transmission lines, loaded with Nestorovic 10" woofers(I build them in 1980 to go with the Acoustat Model III's I had then). The highs are powered by a pair of Modded Cary SLM-100's(TungSol 6SN7GT round plates/Sylvania 6SN7W/JAN CHS) and the lows- A modded Hafler TransNova 9505. I'm using a TacT RCS 2.2Xaaa to split the signal. Being single(again), the room was treated with a goodly amount of Auralex and LENRD bass traps(not the cause of my singularity though). I use Kimber's KS-1130 interconnects, and Wireworld Eclipse5(top)/Kimber 8TC(bottom) speaker cables. Does your system sound as bright using your NAD as the source? I'd be willing to bet your Sony is deficient in the mids and lows, making the system sound too thin. You've got decent gear. How close is your listening position to the speakers?
Wow, that sounds like you've put a lot of time in your system. Have to admit that I'm not quite that dedicated, haha.

It doesn't sound much different with the NAD tuner, but then again, I'd really have to do some listening since I hardly ever use the tuner.

My listening position is about 10ft from the speakers and the speakers are about 7 1/2 ft apart and not quite 1 ft from the wall (windows I should say) and I can't bring them out much more.

I thought about taking my amps to the PMC dealer and to hook it up to the PMC's and see what it sounds like, but since I just bought something for another expensive hobby I couldn't afford them anyway right now.

Since he has Rega as well I'll see if he'd let me audition Rega CD player home. People seem to be happy with those players of what I've read.
Music has been a great love of mine for that past 45 years. If what I hear in the home doesn't live up to what I hear live(two or more times a week, acoustic and amplified), I can't get enthused at all. Most of what I own didn't cost much but my time to mod it(and the parts). The most expensive pieces were the VK-D5 and TacT(about 5K each), then there's the cabling. The cost of NOS tubes nowdays is what's scary. By all means: If you can audition a Rega CDP in your home- do so(before making other changes). That will answer whether the problem is source related. I've never heard anyone describe Electrocompaniet gear as bright. It can't hurt to take them to the dealer, but there are a lot of variables that way(different room, speakers, source, wires). Then again: If they do sound bright in his system too.....
I'm not sure if the Electrocompaniet gear is what makes it sound bright. When you search for threads regarding the B&W 703's here it sounds like I'm not the only one having that problem, so for now the Electrocompaniet's will stay.

Not sure how easily I could sell them but so far I've never seen the AW220's stay for too long here in on the forum, unless people take them off because thay can't sell them.

If I can get the Classe CA-2200 for a good price I'd probably take it, but first I'd have to sell the EC's and for now I think it makes more sense to improve the weakest link in the chain and go from there.

Tubes did come to mind but I know way too little about them and so far everybody recommended amps that have around 200W/channel for my speakers and so I'm not sure what would match my speakers as far as tube amps go. And again, I could end up with something I don't like and be back to getting a better CDP first.

I actually just saw whole box full of tubes at a local auction house and wasn't sure if they were worth bidding on. In the end the whole box of them (around 200 of them in original packaging) went for about 30 bucks. But I don't know anything about tubes and these may not have done the trick for anything.

Ok, gotta go now. I'll talk to the Rega guy this week and see what he says. Might want to do some research here first though.