No, You Cannot Bi-Amp

01-18-12: Elizabeth
In my mind biamping is a 'teenage' phenomenon.
If one is good, two MUST be better.
Yeah a few folks are able, with effort to make it work for themselves.
In general it is a waste of time, if as much effort was made to have one amp work well.
The worst side of it is all the folks who know nothing about it wanting to do it as if it is some easy magic panacea.. Gee I could biamp,,Cool!.... NOT.

OMG, there you are again spewing BS on a topic that you have no technical knowledge of (& once again you have to be reminded of the same). Like in many other similar posts of yours,I have earnestly requested you to not write garbage on a topic esp. if it calls for a technical explanation. This only continues to spread "old wives tales" on the subject matter which disallows this audio community from getting more informed. This request is being made once again....

Mitch4t,
here is a nice (& lengthy) article on Series vs. Parallel Crossovers.
http://sound.westhost.com/parallel-series.htm
You can see (immediately) that the series crossover has only 1 input hence bi-amping is not possible (the author states this himself as well). From this article & the technical measurements it's quite clear to see that (iffffff) the series & parallel x-overs are done right, they are nearly identical (& the author even states this in the concl para) in their performance so this hyperbole of the Maggie 20.7 x-over being much better than its prev revisions due to it being a series x-over is pure BS! The 20.7 xover might/must be better (I've not heard the 20.7 myself) maybe because Magnepan decided to spend the time & patience to do it right after all these years?? (speculation on my part but who knows the exact reason for it being better - certainly not due to it being a series xover...)

Hi Al,
Like-wise, you yourself have a lot of technical expertise & your many answers to forum posts written in a congenial manner have been appreciated by me & many others as well.

Where I was coming from was:
* Elizabeth's post, to me, definitely seems like a rant (look at the way it starts off) & it seems to show that she has some grudge against this technique for reasons best known to her.
* she goes on to say that it's not "cool" to biamp but does not say why. In my mind that's where the technical implausibility comes in by omitting the technical reasons for not doing it. Thus, the forum only knows that it's not "cool" but is no better in knowing why not. Since this topic has been brought up by the OP why not discuss the merits & de-merits so that all visiting members can walk away educated. Aren't we in this audio forum to learn & share the knowledge? I don't think we are here to make blanket statements & walk away leaving everyone wondering...
Anyway, that was my angle FWIW. Best Regards.

As for Bombaywalla, I realize his need for clarity and precise arguments is bothering him when he reads my posts.
I tend to be oblique, and assume folks have some basic sense. Also perhaps he is not really getting some of my subtle humor?

To Elizabeth & all the other men: yes, this is the issue that I have w/ many(but not all) of Elizabeth's posts where I've written a rebuttal aimed at her.
Sometimes I get your humour but sometimes I do not.
I'm not totally rankled or totally mad but the lack of precision does get me off & on (I do not always rebutt Elizabeth's posts & she knows that).
As far as a woman knowing about audio - that has never been an issue for me. I welcomed it when I first started out on A'gon & I welcome it now. Au contraire, I wish that even more women would join the audio hobby & share their experiences. It might make for a more balanced exchange of ideas.
So, you men can stop making these massive leaps in your conclusions about my having issues with women knowing a lot about audio. I do not have any such issues.

And I look forward to years of you shaking your head in disgust at my writings.. LOL

yeah, LOL indeed. Sorry to disappoint you Elizabeth I won't be doing that now that you have stated your angle of writing such posts.

01-20-12: Magfan
Relative power needed is almost entirely governed by crossover point.

If you crossed over at 10khz, you could make due with a 30 watt tube amp on top of a 300 watt SS.

Than, other issues would come to the fore.

Right! A major "other issue," if the two amps are being used in a passive biamp arrangement (i.e., without an active crossover ahead of the power amps) being that some number approaching 270 watts of the 300 watt capability of the SS amp could not be utilized, without clipping the 30W amp. Essentially the 300 watt amp would be reduced to not much more than a 30 watt amp in that scenario (the exact value depending on the voltage swing capability of the 30 watt amp). Which was exactly my point.

Best regards,
-- Al

if you are going to use the in-cabinet speaker x-overs as-is then the best way to do passive biamping is the method done by member 'jefferybehr' - he's used 4 identical amps that are driven by his preamp. Take a look at his system pix.