Bi-amping


Does bi-amping only benefit sound quality if your really driving your amp hard? I have a Mark Levinson 23.5 which is pushing my B&W 801 series 3. This amp is a beast and I never push it anywhere its max. I have an opportunity to purchase another 23.5 but don’t want to buy it just to buy it. If i’m not going to benefit in sonic performance, I wouldn’t want to do it. Any thoughts?
3a4e1df6 59ac 4e6e 8a27 f6591e7fd810luvrockin
bi-amping benefits sound quality if you're listening only at one volume setting and only on compressed and limited recordings.

other cases single amp is much better.
Monoblocks should have a definite improvement on sound reproduction.
Especially if you can put them as close to the speaker as possible.
Short speaker wires will improve sound considerably.
B
To get the real benefit of bi-amping you need to add active crossovers and bypass the passive crossovers in your speakers.  Then you'll need some measurement tools to dial in the crossover frequency, slope, etc.  A lot of work but definitely worth the effort, on my Matrix 802/3s.
luvrockin
If you are looking for better performance consider getting the Bass Alignment Filter and Bi-wiring. Your speakers as is, due to the box size and the way they were tuned, will play down to 39 hz. They do not play the bottom octave. If you want to hear the bottom octave consider acquiring the Bass Alignment Filter, that they were designed to be used with. 

39hz - 20khz without the BAF
20hz - 20khz with the BAF.

The BAF would give them potential for full range down to 20 hz. But they still need to be spaced properly in the room to achieve this. I show a past pic of my 801 (room and spacing) in my virtual system.

Good luck


Depends on a lot of things, how difficult your speakers are, where they are difficult, and how solid the power supply of the amplifier driving it is.

There's one major benefit to using bi-amping however, and that is the ability to use a DSP eq on just the bass section. This allows you to get most of the benefits of a dedicated/room corrected subwoofer, without having extra hardware between your speaker and DAC for the mid-treble regions.

Best,


E
Depends on a lot of things, how difficult your speakers are, where they are difficult, and how solid the power supply of the amplifier driving it is.

Erik
801 matrix 3 (and 2) are an easy 6 ohm load with the BAF. See pic 23 on my virtual system. Easily driven by even tube electronics tapped on 4 ohms.
Biamping you need an external crossover to do it properly.
Also biamping is really best left to pros.
It IS difficult to do properly.
Easy to do wrong.
If you have nothing you really want.. more power.. etc. then I say forget buying the second amp.
Hi CT,

Just looked at the Stereophile measurements. I have to say, those were among the best B&W made, at least based on that!

https://www.stereophile.com/content/bw-matrix-801-series-2-loudspeaker-measurements

I would disagree, but just a little, about them with tubes. While the impedance barely drops below 6 Ohms, the rise to over 20 Ohms at about 2 kHz (text says 15, chart says more) could cause a little trouble. I would be tempted to add an impedance correction circuit to see how it behaves.

Best,

E
Sorry for adding more. 

What's interesting also is the impedance rise in the treble, along with a drop in response in the top octave. This is a speaker which might actually cry out for a tube amplifier to bring out the most output in that top octave.

This combination is not uncommon, especially for speakers of the era. 

A solid state amplifier would ignore the impedance rise, and present the top octaves as JA measured. 


Best,

E
Erik
the links you are showing are for the Series 2 801. The 801 that the OP is using, and that I used previously is the Series 3.

There were changes with the Series 3 - away from the Studio requirements and toward the Audiophile; so much so that the Sound Anchor stands for the Series 2 won't even fit on the S3.

S3 used a different crossover than s2 - less component count.
Better isolated mid and hf boards.
Bass inductors with an iron dust core .
Rotating midrange – tweeter head assembly was permanently connected. (from 3 to 4 pin delivering separate ground signals to midrange and tweeter)
Magnetic fluid cooling of the tweeter (like the 800 matrix) - the reason the apoc protection eliminated (circuits needed for this were also removed)

Here is the impedance graph for the 801 S3 sent to me by B&W England years ago. All markings are theirs.

801 Matrix S3

Cheers Chris
Some of the info above is not accurate. Anyway, I’m not sure it would be worth it and this is coming from someone who’s bi and tri-amped for 40 years. Your B&Ws are a relatively easy-to-drive load averaging around 6 ohms with a complementary manageable phase angle and you’ve got a great amp with plenty of power with somewhere around 300 watts RMS at that impedance. You have adequate power.

First, to go active line-level bi-amping, you must be able to bypass your passive speaker crossover components or the whole effort doesn’t work. Finding a good active XO and bi-amping is going to be expensive. Even if you can, to dial it in properly and match signal levels, you must use measurements - dozens of them. You can’t do it by ear unless you can hear .5dB changes. You should use the same amp which you are considering-good. The whole thing’s very fiddly, time consuming, and frustrating to get it right. Done improperly, it’ll sound totally worse.

Don’t take my word for it, check out what Jim Smith (Get Better Sound) has to say about it. I learned this the hard way because I did it wrong for more than a decade. My system never sounded right. To see what it takes to do it, check out my system comments from 2012 to 2015 and read the trials and tribulations, then go spend your money on something more fun and effective.
Luvrockin Maybe you’re still thinking about it?

Here’s an excerpt from Nelson Pass in the Intro of the Pass Labs XVR-1 product manual. It’s the bible (literally at 20+ pages) on active crossovers basics, theory, and how to set them up. Have at it.

" Some audio products are designed so that you plug them in and you don’t have to fool around with them for a year before the system is greatly improved….".

http://www.passlabs.com/sites/default/files/XVR1_om.pdf
Thanks for all the input guys, taking it all in and is a lot to digest. Greatly appreciated.
get yourself adriverack  dbx pa2 .it processes everything between your preamp and speakers .yes i know it's digital but for me there is no sound coloration  that i can hear.you can bi amp and triamp.it will do everything you need but i mainly use it for crossover frequencies.there is also an app you can download so you can dial everything you need onto your i pad or laptop and adjust all parameters on the fly while listening to your fav lp.you will not look back i promise.just my tuppence worth.