No, You Cannot Bi-Amp

Have to agree with others here who dont see the need for a rant when someone admits they dont know something. They're asking those of us who do have the knowledge and experience to share that knowledge, which is how they become knowledgeable> Did all of us start off knowing everything there is to know about audio? Come on guys and girls,I admit I dont know everything there is to know and I've been involved in this hobby since 1986. Ok, my rant about ranting is over.

JohnK, thanks for your comment.

To be sure it's clear to everyone, I'll repeat that the issue I cited, involving a large disparity in power capability between the high frequency amp and the low frequency amp, just applies to PASSIVE biamping, in which the only crossover that is present is the one in the speakers.

I'll add that my comment was intended to apply to the situation where a single pair of speakers is being passively biamped, with the single pair of speakers having been designed to provide reasonable results (in particular, some semblance of flat frequency response) when driven by a SINGLE amplifier.

John's comments about combining Class D and SET, etc., apply to a different situation altogether.

Regards,
-- Al

Almarg's arguement makes sense to me. I believe that using two amps via the passive crossover ought to be called "dual amping" to distinguish it from true biamping using a line level crossover.

I performed testing to determine how powerful an amp is needed to drive my MG1.6 after lows are removed to an auxillary large cone driver system which I use as a subwoofer. I tested for a wide range of crossover frequencies. What I found was that the high frequency signal needed a lot more "power" than I expected. "Power" is in quotes, because what I was measuring was voltage peaks when playing music at high volume. Voltage swing is what is necessary to avoid distortion. Because the peaks are very brief there is no doubt that the power is actually low. But, because of the way audio amps are designed you have to buy power to get voltage.

Bottom line... don't skimp on the high end amp.

A long time ago I had new Mirage M3si speakers which could be biamped.

So I did what anyother audiophile would do, I tried biamping.
I bought two Brytson 4B amps.

I tried them every which way, and then even as mono blocks.

No magic solution.
Perhaps it was the fault of the speakers, but back then the amps and speakers were well respected.

What I eventually settled for was a one amp solution and I even turned my back on the bi-wiring option.

The best sound I got was with one Bryston amp in stereo, and an easy rewire of the Mirage speakers(just re-arranging the internal speaker wires at the posts, no soldering required)so that one pair of speaker wires was all I needed.

Perhaps bi amping and biwiring do make a difference in other situations, but in my case they weren't worth the expense or bother.

Now I have Ref 3A Grand Veena which are also bi wireable(not biamp as I understand )and so far I prefer to run single wire (Nordost Heimdal) with the Nordost jumpers in the diagonal position.

I tried various speaker wires and none of the biwiring configurations I tried were any better than the way I have them wired now.

I ran my Maggie IIIas with an Audio Research D400 for years, then bought another D400 and used the XO1 passive crossover but quickly got myself a Marchand electronic crossover which cross to a pair of subs below 50hz then uses same slopes as Magnepan suggests bass to mid/high

To my ears the difference was pretty significant and and I haven't been a teenager for decades (sorry just being flip)

I thought one advantage was the quality of the crossover itself and limiting the bandwith each amp must produce

Supposed to audition the 3.7s in a couple weeks so will find out 1st hand what they sound like "out of the box".

Audio Research says that the D400s will drive the low impedence load presented by bridging the amps and driving Maggies so can use both amps still but again my ears will be the judge

I doubt I will pull the trigger until I can hear the 20.7 and check out some other models at the Capital Audi Fest this summer but "once you go Maggie you seldom/never go back" :-)

MikeH