I am not an exper this field, but I know it is an impossibilty to sum the left and right channels of the amplifiers to receive both L and R outputs from the preamp, unless you are sending out a mono signal or you use an adapter to allow the left and right output cables from the preamp to somehow merge with the inputs of both amps. Therefore, you do not have to worry about having the intended stereo channels crossing into each amplifier. They are separate. Each amp will drive either the left or right signal to the intended tweeter/midrange woofer connection and the amp should be able to supply voltage and current as needed for each driver connection. It is completely autonymous from what the other channel is doing in the other amplifier.
I would love to experiment biamping with some SS amps with my tube amps just to test the waters. I am thinking the new Wyred4sound might be an interesting configuration.
Ciao,
Audioquest4life |
I just came across this thread while browsing. Coincidentally, I started vertical biamping my Sony SS M3's with two Rotel RB-980BX's (2x120) just about a month and half ago. Previously, I had been using just one of these. Removing the binding posts and adding the second amp made a huge difference. Night and day. After reading this thread, I ran over and switched them from stereo to bridged mode. The volume jumped dramatically, inversely proportional to the quality change. Ick. The sound was very thin, almost fuzzy. Maybe I need to wire them differently? I'm looking forward to an active crossover. I'm sure this will yield significant improvements.
By the way, the preamp is a Lexicon DC-1 with "Bypass" engaged, no bass/treble adjustment, no Loundness Contour, etc. My source is a basic Sony Bluray player connected to the DC-1 by toslink. I lucked into the Lexicon and Rotels (both needed repair). The speaker purchase was a craigslist shot in the dark that I feel turned out very well. :) |
The 801`s have a crossover that requiers the high/low wire to be removed which sepatates the frequencies and allows the bi-amping to be done. I'm running the top/high end with the Xindaks and the bass with A pair of Bryston 7B SST`s. XLR for the Xindacs and RCA for the Bryston..only one pair of output XLR on the pre-amp. Wonder why they didn t add two...lol.. D.
Thanks for the input Rf. |
If you have spent the money to bi-amp your system, my suggestion is to go the extra step and get an electric crossover. In my humble opinion, this produces the best bang for buck upgrade in sound. |
How's this one for the experts...i'm putting together a system consisting of B&W 801,s series 2, Bryston BP-25 pre amp and 4 Xindac mono blocks, One for the left woofer,one for the right woofer,one for the left mid and tweeter and one for the right mid and tweeter. Should I use xlr connects to the amps or rca from the pre amp? I will have to remove the two wires from the crossover on each speaker. Will every thing work perfectly and give me that power reserve to keep these amps in Class A with a bit of volume. I found that with running just the two monos on these speakers I had to crank the volume control 90% maxed to get the room to shake...lol. No complaint of the sound comming out of the Xindaks...just want more of it. Thanks D. |
I currently have both vertical and horizontal. Bass amp, (semi) active xover, and dual amps bridged to mono (Plinius does this easily). Previous setup also had 3 chasis but the uppers were born monoblocks and it used the passive xover of the speakers and a DIY attenuator. The advantage of an active xover is that it allows you to get rid of the passive, parasitic cancers. Nothing to do with limiting the bandwidth going into the amps and whatever they "think". Before considering an active xover, consider the surgery on the speakers and whether the passive network can be approximated externally.
The limited success of either method of biamping only suggests how the complexities are misunderstood, general ignorance, or a lack of patience. Some might say, "if you gotta ask, don't ..." , but that takes all the pain from learning.
Whether a stereo amp can or should be bridged to monoblock is dependant on the construction and the speaker load. Apparently, few should and much of the point is moot if the amps are already balanced (differential).
I agree with Steve that bridging is preferable, if available. If he says it would be good with your speakers, go for it. Often, the output wattage is quadrupled. Many speakers have the crossover point way too high to have any advantage for passive biamping.
Good luck |
Nice post Aball.....I have heard those things and did try both ways and preferred horizontal for image.
ET |
""
Sorry Arthur but Descartes proved you wrong a long time ago, "I think therefore I amp"!""
Why you!
You missed me! Nyuk nyuk nyuk!
ET |
An amp doesn't "think" about what it sees. It only sees what it's hooked up to and that is it. Sorry Arthur but Descartes proved you wrong a long time ago, "I think therefore I amp"! |
Aggielaw - An amp doesn't "think" about what it sees. It only sees what it's hooked up to and that is it. Each channel is on its own and has no idea what the other is doing (this is not absolutely true because of capacitive coupling but in the grand scheme, the channels are independant). As a result, there cannot be an imaging issue.
However, there is a current imbalance in the amplifier between channels since one side sees a (generally) easier load in the treble and the other has a heavy load for the bass. BUT, this issue is also moot because a good quality amplifier will have a power supply of sufficiently low output impedance that the imbalance will not be reflected in the crosstalk, nor as a power rail voltage differential.
The advantage is that the power supply is much less taxed than it would be driving the entire speaker. The reason for this is two-fold. One, the high side is generally a 3x easier current load than the bass.
The other is that you no longer have the impedance of the highs and lows in parallel. Using a single pair of cables on a biwire speaker means that the amp sees the speaker's impedance for the highs and lows in parallel. Let's say the bass is a constant 4 Ohms and the highs are a constant 10 Ohm load. The sum total of both together is 2.8 Ohms! The reason this isn't reflected in the impedance plot is because the plot is generated by a sweep, so only one frequency is produced at one time. But with music, you have thousands of frequencies all at the same time which effectively puts the two halves of the crossover in parallel, as far as the amp is concerned. This is a big problem for an amplifier power supply and is also the reason that some hifi companies seem to have gone overboard in sizing it. It is because their job is tougher that it first looks.
Vertical biamping can result in impressive improvements in dynamics and detail simply because the power supply isn't as heavily loaded. I have been designing amplifiers and it is clear the power supply is really what the performance level boils down to.
I horizontally passively biamp and love the results. Absolutely fantastic - and each amp sounds way better than it can on its own (for its respective frequency band, that is). It does make a big difference.
Arthur |
Steve's answer doesn't surprise me at all. I recommend bridging AND biwiring. Like Reeses; two great things that taste (sound) great together! :) |
I tried vertical and horizontal bi-amp and preferred horizontal. My amps are CJ made in the same building as yours. Don't bridge. As to your scenario the amp doesn't know or care what it's sending in terms of L/R. It's up to you to put the correct signal into each input jack that you want to come out of the output.
ET |
Hi, I'd like to run one Snell EII or JII per amp (Yamaha P1600) and am wondering if this is advisable? I'm reading mixed things about "vertical bi-amping" online, and the original poster of this thread makes a valid point about his confusion regarding signal distribution/break-up. So, I'm confused: If I power the high-end tweets on the EII with, say, the left channel, and the low-end bass/woofer with the right channel, won't that be cutting the intended music in half, by eliminating the recorded highs being sent to the right channel and the recorded lows being sent to the left channel? Thanks, Brad |
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Creeper...If everyone agreed about everything all the time the discussion would become very boring. How can you get so worked up about semantics? Resort to personal insults usually results from a weak argument. |
Eldartford
Yes, dual sets of posts facilitate bi-wiring, as well as biamping. Do a search at Audio Asylum under the amp/preamp section and you'll instantly find 200 examples of an industry standard term. There are 88 examples of it in discussions here too.
I've come to realize that you like to stir things up just for the sake of stirring. This is the last time I will ever fall victim to your muck rucking.
Happy listening. |
Jeffreybehr...I always heard that connecting two power amp outputs in parallel was a NO-NO. Frankly, I never tried it, as the caution seems reasonable.
Creeper...The "industry standard" when I started biamping in the mid 50's always involved a low level crossover, and I think this terminology remained for many years. Only lately have I heard about using two power amps with passive crosovers. Indeed, until fairly recently loudspeakers did not come with separate terminals for woofer and tweeter (a feature intended to facilitate bi-wiring).
Aggielaw...A low level electronic crossover has far less "personality" than a passive crossover. Of course, the "personality" of the passive crossover may be deliberate, to overcome certain known deficiencies of the drivers. |
Dan,
Interestingly, when I asked Steve yesterday about biamping vs. monoblocking (or monobridging, since his monblock conversion bridges the channels of the amp, which he describes on his website at www.smcaudio.com), he stated that he finds better performance with the monoblocks because the amps (his amps, anyway) control the speakers better in that configuration than they do in a biamping setup. He said this results in even better imaging. He is absolutely not a fan of active biamping, because the active XO before the amps inserts its own "personality" on the sound. Steve did say some people have reported not liking biamping or monoblocking, and he didn't really understand why.
I was almost ready to sell my current DNA-0.5 Rev. A to buy the monoblocks that came up for sale last night, but now I'm not so sure - the number of comments of experienced users who say monoblocking or monobridging is a step backward seems to outnumber those who hear the benefits. I don't think I want to fork out the money to find out for myself quite yet. Of course, the negative comments I've heard about monoblocking have not been directed at McCormack amps, either. Might be time to email Swampwalker... |
Eldartford
"dualamping"? Come on...
The term biamping is an industry standard. Any speaker with two sets of binding posts and a truly divided internal passive crossover is "biampable", no? In this situation, far more common than "actively" biamped systems, no external electronic crossover is involved. The term "actively" is what distinguishes the two. |
Hi Aggielaw,
Yes, monoblocks would be connected so that each block would drive a singe speaker, or channel. This is also how it would "look" if you were to run two amps in bridged mode with each amp acting as a monoblock and running a single speaker. Both of these configurations only require a single IC connection from the pre to the amp for each channel, so it is simpler to connect. What I have experienced with the amps that I have tried running in bridged mode is that the soundstage would lose depth even though there was plenty of power. Now, monoblocks are different because their power supplies are built and integrated as a single unit. They are build for the express purpose of driving a single channel. Of the 4 or 5 amp builders who I have asked about running their stereo amps in bridged mode, all have said that while their amps had the current supplies to do it they recommended running them in stereo mode to get the best sound. (Send an email to Steve, I bet he says the same thing.) I have found it fairly easy to confirm this after listening to both configurations using the same amps. So it really is a matter of what amps you're using and what you're preferences are, assuming the amps you're using have the current capabilites that may be required from driving that 4 ohm load that is now seen as 2 by the bridged amp.
Bi-wiring is completely different and is dependant only on how your speakers are built. I suppose the cables used could also be a factor. There can be a benefit from bi-wiring, but in my experience the gains made from biamping (or dualamping for Eldartford) are much greater than the gains from bi-wiring. Also, with biamping you can get the amps very close to the speakers using longer ICs and keep the speaker wires very short. Another sonic benefit I have experienced. As always, YMMV.
Dan |
The above discussions of bridging SS amps are pretty good, but to make a point--bridged amps are NOT 'high-current' amps. Only if an amp has a 4-Ohm rating that's double its 8-Ohm rating will it be able to drive FOUR times the power into 8 Ohms--and four times is the theoretical amount. So if your speakers are 4-Ohm rated or are relatively insensitive...say below 90dB...don't look for a bridged amp. However, the channels of any SS amp can be paralleled, just as the channels of a tubed amp can. Simply drive both inputs with a Y-connector and wire the output terminals in parallel and you have a mono amp with the combined power of the 2 channels. IOW, if you had a 125-into-8 stereo amp, when paralleled it becomes a 250-into-8 amp.
I think passive biamping makes sense only when you intend to use amps that are (more or less) well suited to driving parts of the audio spectrum. Let's say you have a overall sweet-sounding amp that just doesn't have enough power to produce the bass 'slam' diddeeboppers love. Connect it to the MR/treble part of your 3-ways and buy a SS amp noted for its bass performance. After level matching, you have what MAY turn out to be a QUITE-fine-sounding amp system.
IMO, biamping AND biwiring benefit equally from using speakercable selected to carry parts of the audio spectrum, same as amps. If driving bass only, select a cable with lots of material for low resistance but that's still inexpensive, such as AQ's Type 6. For MR/treble, select a cable that has excellent material and geometry for critical listening but that's not too high in gage or expensive. For this, I'd use AQ's DBS-type CV-6 or KE-6, both using 4 pairs of 4-different-size conductors. If driving treble only, I'd use AQ's all-silver, DBS-type KE-4 at half the price of KE-6.
All of this is controversial, but my experience over the decades supports it. As always, listen carefully and be cautious.
. |
Hmmm...I thought if I went to monoblocks one amp would drive each speaker, which then naturally leads to an apparently hotly-contested issue of whether biwiring (two sets of cable connected to the one set of output binding posts on the amp?) would be worthwhile.
Am I missing something?
Thanks again for thoughts and guidance! |
S7horton got it right on the money about sending only one channel to each amp. You either need the y-adapter or two sets of ICs.
I also agree with Eldartford about the effects on the power supplies when running the amps in bridged mode. But you need to remember that you are effectively cutting the load seen by the amp in half when running amps in bridged mode. The effects of pulling more on the power supply from one side vs. the other as with the vertical connections can be compensated for by periodically switching the side that drives the woofers. In my brief experience with bridging I have found that the amps run hotter and it just doesn't sound as good. This is very much dependant on the amps you're using. If the amps can be converted to true monoblocks, then you will probably get good performance from them. Check with the manufacturer of what ever amps you're thinking of using and asked them what they recommend. |
I object to the term "biamping" when the amps are not fed hi and lo frequency signals from an electronic crossover!! How about "dualamping".
My experience with bridging has been good. When you bridge a stereo amp one channel is using an out of phase signal, which evens out the draw from the DC power supply. One "specmanship" trick of power amp manufacturers is to cite continuous power with both channels driven...and in very small type, if at all "out of phase". |
Your explanation of vertical biamping is close. Each channel does send out full range signals. However, when you run a signal to the amp from the pre amp, it's only one channel. You either need two sets of outputs on your preamp, or a "Y" adapter so you can send two line outs of the right channel to amp number one. Does that make sense? I'm not sure if I explained it well or not. In other words, amp number 1 never sees the left channel signal. |
