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HiA question. If I vertically bi-amp a pair of speakers (ie 1 pair of monoblocks for the LF and one pair on the HF) have I doubled the power going into the speakers? So 2 pairs of 20W amps becomes 40Ws going into the speakers or is it still 20W only?
Follow Ups:
Each monoblock can output 20W, so the woofer cannot go above 20W or the tweeter cannot go above 20W. Overall, the speaker cannot sound more than the 20W (or rated capacity) of the amps.
But there are benefits to doing this in the following situation i) the impedence of the speaker is not flat ii) the damping factor of the amp is not that great. In this, any variations in the impedence of the woofer or tweeter will not affect the other. Mostly, bi-amping would reduce the harshness in the sound of the setup.
Only when you bridge the amps (ie. the output devices are in series) does the current output from the amps increases and hence the rated power output.
This is not the question you ask but your statement on vertically bi-amping monoblocs suggests confusion shown here from time to time.To vertically bi-amp a pair of speakers would require two identical stereo amps, one for each speaker. One channel from each amp would feed the W input and the other channel the T or M/T input. Many prefer this configuration since it separates the power supply for the woofers.
A horizontal bi-amp would connect one stereo amp to the woofers of each speaker with a second stereo amp driving each T or M/T. This allows selection of different power ratings (as Jeffrey notes) to better match driver needs, or even SS on the W with VT on the T or M/T. If done passively, some means of gain setting will be needed.
Basstwo, since you mention monoblocs, I don't believe that is normally considered vertical or horizontal although it would offer the option of using different amp models for the W and T or M/T, similar to the horizontal configuration with stereo amps.
Agree that I might have confused the point about vertical vs horizontal. I was thinking about identical monoblock amps and that was why I was thinking horizontal...
...but how much of that power is used depends on so many things that your question can't be answered definitively.For instance, treble uses MUCH less power than bass or MR, so if your speakers are 2-ways with the typical split of B/MR on the bottom and just treble on top, probably you'd be not using most of the power of the tweeter amps.* If the speakers are 3-ways with bass on the bottom and MR/treble on the top, probably you'd be using similar amounts of power from each amp.
But I agree with Awe-d--focus on the sound quality, not the numbers.
* When amplifying treble only, most of us use amps of lower power than on the MR or bass.
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Tin-eared audiofool and obsessed landscape fotografer.
http://community.webshots.com/user/jeffreybehr
Thanks for clearing that up a little bit.The purpose of the question is really to see if a switch to bi-amp could make a meaningful difference. Not that I want to focus on numbers per se but that is something certainly something that I thought could be more objectively assessed (maybe not!!). There is after all a cost involved and unfortunately I can not try before I buy. My setup is your typical 2-way with one B/MB dirver for the LF and the tweeter for the HF.
What I am little confused about is that if most of the power is already going into the B/MB in a single amp situation (say 18W into the woofer and 2W into the tweeter with a 20W amp, for instance), then presumably the benefit of going bi-amp is not really an increase in power? That is (again using my earlier example) I would be seeing 20W going into the woofer and 20W into the tweeter with 2 identical 20W amps (and not 40W)?
"What I am little confused about is that if most of the power is already going into the B/MR in a single-amp situation (say 18W into the woofer and 2W into the tweeter with a 20W amp, for instance), then presumably the benefit of going biamp is not really an increase in power?" Yes it's not, at least in this situation."That is (again using my earlier example) I would be seeing 20W going into the woofer and 20W into the tweeter with 2 identical 20W amps (and not 40W)?" Did you mean 2W into the tweeter? In fact there simply isn't as much Voltage drive in the 3 octaves of treble as in the 7 octaves of B/MR. In this situation, biamping with 2 identical channels of 20W each would be wasting about 90% of the power of the treeter amp. Of course, there may be other reasons to choose that 20W. amp.
You write as if there's always 20 Watts being output from a 20-Watt amp. 'Tain't, simply said. That rating is the maximum power available under specific circumstances. If the Voltage input is, say, 30dB below that needed to drive the amp to 20 Watts output, then the amp's output is 30dB below 20 Watts or about 0.02 Watts.
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Tin-eared audiofool and obsessed landscape fotografer.
http://community.webshots.com/user/jeffreybehr
Ok that clears it up a bit. I was trying to reconcile what you mentioned compared to the post by andyr which seemed to suggest otherwise. Wasn't sure...
My experience is really only with active setups ... which yours isn't! :-))Regards,
you're using the stock passive XO in your speakers or not.Option 1: your using speakers with 2 pairs of Binding Posts (1 for LF & 1 for HF) and a passive XO inside the box. In this case, IMO you are getting somewhere near 40w to the speaker. However, they should sound better because the highs are no longer being compromised by current-sucking, heavy bass action! :-))
Option 2: rip out the internal passive XO and substitute an external active XO. In this case the XO goes between the preamp and the 2 power amps, and the power amps are directly connected to the drivers.
In this case 2 x 20wpc active delivers you the equivalent of 80wpc into the passive XO.
Option 3: rip out the internal passive XO but substitute an external Passive Line Level XO. This goes before the power amps, just like Option 2 but consists of passive components, not active. This is a great way to go but is limited in its application ... it's ideal for speakers which have first order XO slopes. IMO, this would give you the equivalent of more than 40wpc but possibly not as much as the 80wpc in Option 2.
Regards,
I do this very thing and it helps a lot. Helped the image a lot too. I think its horizontal bi-amp though, not vertical. Don't get hung up on the numbers, focus on the sound improvement.
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