So...instead of just listening to other peoples' opinions on this forum (and not knowing if they have actually did a comparison between bi-amping or not or if they are just regurgitating someone else's remarks they've read elsewhere), I decided to do the test on my own here. Remember, I'm walking into this not knowing if I will hear a difference since opinions vary here, so I'm not biased one way or another.
My conclusion: those of you who say there is no difference with passive bi-amping need to clean their ears. There is a difference, although I'm having a difficult time interpreting just why this difference exists. It's not subtle either, and honestly, I'm not used to my audio sounding this way so I don't know how to interpret it. It's very different...
The test:
My system is in a normal carpeted room (LxWxH = 25x32x8) that is "untreated" by hifi standards. Each speaker sits 30 degrees off center with a distance of 10 feet apart and 10 feet from my listening position...with appropriate toe-in.
Equipment:
Ayre K-1 preamp
Meridian 508.24 CD player
Theta Dreadnaught amp (200x5) (x2) (on Transparent Powerlink Super)
Dunlavy SC-IV/A speakers
Respectable equipment I think (I like it) to observe some sort of result or not. I plugged everything directly into wall sockets (each amp had it's own and didn't share with anything else).
I used two pairs of Transparent MusicLink Super balanced interconnects out of the Ayre K-1 into two channels in each of my Dreadnaughts, and had each Dreadnaught assigned to one speaker. This works great to keep channels separate from each other since the Ayre is also a dual mono design. Both pieces are a zero-feeback dual-differential design. In each Dreadnaught, one channel powered the "high post" and one channel powered "low post". Usually my CD player is run dual-differential balanced, but since I stole the other balanced cable from the player and used it for the second balanced output from the Ayre, I had to use a set of RCA interconnects, and so I used a set of Synergistic Research cables I had sitting around.
For speaker cable, I did the unthinkable for hifi: I replaced my Transparent MusicWave Plus BiWire cable with two lengths of standard 16awg for each channel. As much as I love my Transparent, I couldn't use it in this test because the cable isn't designed for a bi-amp scenario. So the easiest thing to do was cut some 16awg off a spool and work with that. It'll do for the test.
I started immediately in bi-amp operation. I put each Dreadnaught in stereo mode and shut off all other channels. Volume on the Ayre was set at approximately 10 o'clock. I played with only one CD tonight (and will try some more over the next few days when I have time). Tori Amos's American Doll Posse - not a bad recording, but not one of the best either. It was the only way I'd get to do this tonight and have my girlfriend sit in on this after I did some of my own investigation. The songs I chose to listen to were Mr. Bad Man and Roosterspur Bridge.
I listened in bi-amp mode. Bass was good. There was something to be said about the air in the midbass and treble area, but I didn't know what it was. For all I know, the single amp mode could be the same. So I spent time taking the 16awg out of channel 2 and putting it in channel 1 with the other wire making the speakers single amped but biwired, just as I've been used to.
The volume knob did not change.
Playing the CD required no adjustment of the volume level. It was the same whether single-amped or bi-amped.
The sound: Immediately I could tell that the bass was not as defined. I mean, it wasn't even close. What was clearly distinguished in bi-amp mode was the drum pedal and bass guitar. In bi-amp mode I could hear both independently, defined, and I'll say seemingly accurate. When listening to the speakers off one amp, the bass was still strong, but clouded. The definition was now gone...or mixed up at best. I could no longer hear the drum pedal always separate from the bass guitar. Sometimes I could, sometimes they were together as one sound. Funny how I thought it sounded good before. Biamping also made bass dynamic range seem to improve more rather than sounding linear as it did in single-amp mode. All of this is easy to explain. Each Dunlavy has two 10" Scanspeak woofers in them. Maybe, just maybe biamping improved their performance...?
Now for the tricky part...
In bi-amp mode, treble, for the most part, didn't change much. I did notice slightly less sibilance, but Tori Amos's voice in the recording tends to be a bit sharp around the edges some moments. While center focus also seemed similar, what seemed to change dramatically was the space between all elements in the mix...as well as their volume levels...hmmm...and that is what is throwing me off here.
Sounds in the mix that were more forward in single amp mode appeared quieter and less intrusive in bi-amp mode. It's like some sounds actually took a step back and became modest. On top of that, all the instruments seemed to carry a better space of their own as if they asked for some personal space from everything else in the mix. And this, my friends, is what made listening to the recording very very different. I really didn't know if this was a good or bad thing 'cause I haven't heard it this way before - ever. It's almost "polite" on the ears.
I also found that what was perceived as being slightly more dynamic (vocals) in single amp mode was now slightly modest when biamping. Why this is, I don't know. But that's what I heard. Maybe it has to do with the next point.
When switching it to single amp mode, everything was there and active at once - still sounded good as I've always heard it, but all things in the mix began to sound as if they were at a similar volume level...more compressed in a sense...and what was apparent was that the definition of all sounds wasn't as good as in biamp mode. It seemed the mids and tweeters on my Dunlavy's had more to work with now and were better able to portray the recording.
When inviting my girlfriend to listen (who I always consult with for my audio needs because she loves music just as I do and loves listening too, plus her ears are slightly more sensitive than mine), she gave me the exact impressions back. She had no idea what experiment I was conducting - she was doing her own thing in another room when I was doing all of this, nor did I tell her beforehand. I told her to listen twice. I didn't tell her what I was doing at all.
I played the two tracks. I did biamp first. Single amp second.
What I found, she found, although expressed it to a greater degree than I found. She made the comparison of the second listen (single amp mode) as to what she's used to hearing - here at home or in her car - everything mixed together. She too noticed the "space" difference (and bass) with biamping. She didn't know how to take it either, but when asked to choose one or the other before I told her what I did, she chose the biamp sound as her choice.
This sort of ticked me off, honestly. For one, I was hoping there wasn't going to be a difference, or at least one that I was going to appreciate. The fact that my girlfriend gave the same feedback as my thoughts without her knowing what I did just confirms that I'm not fishing for a difference, but that a difference (and a positive one) exists.
Second, now that I know I'll want to keep biamping, I have to change speaker cables. This is going to be more of a pain in the butt if anything, but I'll figure something out. I didn't want that to happen.
So there you have it. These are my observations. Take them as they are, but to the naysayers of biamping just know that I started this experiment unbiased having no experience with it at all.
Over the next few days I'm going to try some better recordings as well as music from a wide variety of genres. But I think better recordings will probably convince me more to stay with biamping.
In conclusion, I found bass definition much better when passively biamping. Space between all sounds also improved. But why many sounds became quieter than they were in single-amp mode is beyond me, but I'm sure someone will have an answer be it right or wrong, but I'm curious to hear an opinion on it.
)
...I've gone through 7 guitars in the last 10 months, trying to find the sound I want. Finally got it though(funny thing too, as now my pedal board with just 5 pedals has more value than my guitar...still playing a Gibby Les paul, even.
