Am I?
I must have read something wrong. I'll go back to it when I have more time later today.
Mono amp or Bi-amplification
- Thread starter wes
- Start date
Am I?
I must have read something wrong. I'll go back to it when I have more time later today.
The question is the following:
Is there a benefit from using two stereo amplifiers (therefore having 4 amplifications channels, each powering its own driver) vs. a single stereo power amplifier?
- Loudspeaker with two sets of terminals, completely electrically isolated from each other
- One set of terminals controls the midrange and tweeter, the other set of terminals contols the woofer
- Crossover is situated inside the speaker cabinet, between terminals and drive units
- No use of crossover upstream between source and amplifiers
Is there a benefit from using two stereo amplifiers (therefore having 4 amplifications channels, each powering its own driver) vs. a single stereo power amplifier?
I would say no, at least no audible benefit. Without a crossover before the amps, they (all amps) still all see a full-range signal so there is no increase in voltage headroom. There could be some benefit in current reduction because the out-of-band load* is small but I doubt it would be audible. This is essentially what AVR folk call "passive bi-amplification". To benefit in any way you really need a crossover before the power amps; for maximum benefit you also need to bypass the internal crossovers as well.
* The woofer amp still drives HF signals to the speaker, but since the tweeter is no longer connected no power (or very little) is drawn by the speaker itself at HF. VOltage swing at the amp output is the same, but the HF do not draw power. Because most amps look like voltage sources, there is no practical headroom advantage. If the amp were current-limited there could be some benefit, but that is rarely the case for HF signals since they are usually lower in amplitude.
* The woofer amp still drives HF signals to the speaker, but since the tweeter is no longer connected no power (or very little) is drawn by the speaker itself at HF. VOltage swing at the amp output is the same, but the HF do not draw power. Because most amps look like voltage sources, there is no practical headroom advantage. If the amp were current-limited there could be some benefit, but that is rarely the case for HF signals since they are usually lower in amplitude.
No, I am not sure how we crossed wires? I do not know that isolating the woofer from the tweeter actually connects the amps directly to the drivers. I do not believe so; every speaker I have seen (at least that I recall) retains the internal crossover in this mode, i.e. a LPF to the woofer and HPF to the mid/tweeter inside the box. That is easier for them and helps protect the drivers since there is no other crossover in the system.
I'm sorry. My contradictory post was answered based on the blue text in the most recent post by wes, not prior constraints set in his original post you just re-iterated.
Okay, based on what you just posted, the answer would be NO benefit.
If you take out the jumpers, the woofers will be isolated from the other drivers, but your amplifiers will still be working overtime without the use of an active crossover. Without an active crossover the woofers will still be sent midrange and high frequency signals [whose power will be wasted] and the speaker's internal passive crossover for the midrange and tweeter will still be sent the woofer signals [whose power will be wasted].
The woofer must be completely separated from the other drivers and internal speaker crossover AND you must use a separate active crossover between pre-amp and power amps to divide the frequency range BEFORE the power amplifiers to benefit from bi-amping.
I think I clarified the point this time.
I don't have an active crossover!
http://www.bowers-wilkins.com/Speakers/Home_Audio/800_Series_Diamond/800-Diamond.html
Yes, I recognize that. Sorry for the confusion. You would not benefit from adding amplifiers without one.
I was just being more specific in my recent post in response to Don's and AudioExplorations' posts.
You should go with a bigger power amplifier rather than bi-amping if you want to make a change.
Ok so based on taht forget bi-amping, I should just get the CA-M600 vs the CA-2300?
Any amp you get will be working into the resistive element of the crossover, so "direct" connection with its corresponding driver is broken. It would be an interesting experiment for you to audition more powerful amplifiers and see if you feel that there is any benefit during your typical listening.
Lee
Lee
I have not seen, or do not recall, a resistive component in the crossover network to a woofer. Could be wrong, natch, but I have only seen reactive elements (L, C). I have seen Rs to midrange and tweeter (especially tweeter) drivers to help balance the frequency response. In general, yes, there will not be a direct connection to the drivers in this scenario. Not even the woofer; in the designs I have seen there is still a LPF to the woofer coil. I do not claim to have seen all designs, however, not by a long shot.
Its common to have 'BSC' (baffle step correction) to a woofer implemented with a shunt RC network. My current speakers have a series L followed by RC shunt to the bass/mid unit. The R part of the shunt forms a resistive divider with the loss of the series inductor to attenuate the top end of the mid's range by a couple of dBs.
Hmmm... That is in parallel with the woofer so does not obviate a "direct" connection. However, the L is still in series, so still no direct conneciton. I think the main point is that removing the jumpers outside the box does not remove the crossover inside, just splits it into two pieces.
Question wit out taking $ in consideration what do you think
Classé CA-M600
http://www.classeaudio.com/delta/delta-cam600.htm
Emotiva XPR-1
http://shop.emotiva.com/collections/amplifiers/products/xpr1
Classé CA-M600
http://www.classeaudio.com/delta/delta-cam600.htm
Emotiva XPR-1
http://shop.emotiva.com/collections/amplifiers/products/xpr1
You should start a new thread for that. I have not been a huge fan of Classe though many people like them. I own XPA-series Emotiva amps now and have found them excellent performers and a great value. For low-Z loads the Classe may be better. I find it very hard to separate money out of the equation; I can buy a lot of music for the cost difference, or boost the kid's college fund.
Right, and it *should* sound better biamped. There is nothing wrong with passive biamping, in the same way that rare passive line-level xovers can be magnificent. The back emf from drivers, especially from woofers, always affects the feedback loop of an amp, or simply its output rails if it is a zero-feedback design. Biwiring should help a little if more amp channels are too expensive, but no good active monitor uses single amp channels for drivers that cover different bands for the above reason. Even then, you want to take good care of the ground currents. I hate even the idea of paralleled woofers driven by a single channel, but pay no attention to my excesses. The ultimate tool is probably the Hypex DLCP with six channels, assignable as you wish, paired with ncore amp channels. (e.g. Grimm LS-1). The Grimm/Hypex/Mola-Mola crew came out with this recently:
http://www.mola-mola.nl/
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