That defeats the purpose.full range of signals in each channel, but the crossover in the speaker attenuates (filters) the frequencies not used by that set of drivers.
That defeats the purpose.full range of signals in each channel, but the crossover in the speaker attenuates (filters) the frequencies not used by that set of drivers.
When I have time, will check with speaker system with a sub.For me it seemed very apparent. I guess ABX will tell if I heard what I thought I heard. There isn't much low end in the music to mask the rumble.
Biamping causes less IMD distortion , very difficult to measure because its variable depending on the music content . The sound gets better .Does bi-amping make a difference? My Revel Salon2 speakers come with two pairs of binding posts, and the manual says:
Revel does not endorse one particular connection method over another.... The design of this loudspeaker is such that optimal performance can be attained using the standard connection method.
By connection method, do they mean bi-wiring, or is bi-amping included? When I switched to vertical bi-amping (one stereo amp per speaker), I sensed a subtle but definite improvement in clarity of high frequencies.
To start, let's compare frequency responses. In the vertical bi-amp configuration, each Salon2 is powered by one Benchmark AHB2 in its low gain mode, with the high and low frequency binding post each driven by one of the amp's two channels. In the normal configuration, the manufacturer supplied shorting bridge is used and the speaker is powered via one pair of binding posts. Note that in the normal configuration, each Salon2 is still powered by a separate AHB2, i.e. monoblocking using a single AHB2 channel per amp. This means any differences would be attributable solely to separation of high and low frequency amplification, and not to elimination of stereo crosstalk between the amp's two channels.
View attachment 199194
As we can see, frequency response is unchanged. Variations below 50hz are within usual variation on each measurement, so I wouldn't put any credence on differences there. Still, I was not convinced that the difference I was hearing was all placebo. It's impractical for me to do a blind test, given the time and effort required to change from bi-amp configuration to normal. An ABX with enough repetitions to prove audibility would take dozens of changes, each of which takes longer than ideal for our short audio memories.
Recently in my previous experiment, it was shown that recorded speaker outputs can be used in an ABX test to demonstrate an audible difference for a change of speaker feet, so I wanted to see if this ABX method would also work here. I recorded the output of my Revel Salon2 speakers playing music in stereo using a pair of high quality cardioid microphones (Shure SM81), each mic 2' in front of the tweeter's logo.
I've attached sample clips of the recordings. The original is available free on 2L.co. I think you'll agree upon listening that these recordings are a good enough representation of the original to plausibly reveal differences. I did the ABX test using a piece I'm more familiar with, another recording of a classical string quartet.
The difference was minute, and ABX is hard. There's the time, effort, and mental fatigue. The default of 16 trials requires at least 32 intense listenings of the same passage, likely more. It takes training to tease out perceived differences that are real and can be repeatedly ascertained, versus those that turn out to be due to memory blur or too weak to be detected repeatedly with sufficient accuracy. Repeated listening causes a kind of burn in of the senses and memory. Eat a bite sized piece of single-origin chocolate and you can taste the nuances down to the trees that were planted next to the cocoa. Now imagine eating 32 pieces in a row and then asked to distinguish the nuances between the last two pieces.
I only take a test when I'm able to get good accuracy in training mode, and still my first two tests were only 10/16 and 9/16 correct, which led me to devise techniques to limit fatigue and its effects. It helped to identify an extremely short passage of 2 seconds and to limit listenings by reducing trials from 16 to 10, which is a tradeoff that requires a higher accuracy for statistical significance. I did the third test after training and improved to 9/10 trials correct (p = 0.0107).
View attachment 198976
It's no wonder to me now that ABX tests have come up null for all manners of changes. If I were a random subject brought in off the street, with no practice and no incentive to get the right answer, I would have performed even worse than my initial trials and we would have concluded there was no difference.
I do think the real difference is greater than is captured by the recordings, but that cannot be shown by this ABX setup.
TLDR
Vertical bi-amping of Revel Salon2 using 2x Benchmark AHB2 has the same frequency response but makes an audible difference.
I checked with my stereo setup. With just sub on (stereo amp for speakers off), indeed I could sense the rumble with regular clip. However, once I turned on my stereo amp and my speakers start playing, the rumble was masked and I can't sense the rumble. Maybe you can sense the rumble with everything playing, but I can't.For me it seemed very apparent. I guess ABX will tell if I heard what I thought I heard. There isn't much low end in the music to mask the rumble.
The OP admitted he didn't do a blind comparison test.Do you even know what is ABX? You first sentence shows that you don't.....
Instead, he made recordings made with standard wiring and bi-amping, and compared them in an ABX manner. Unfortunately, he didn't run a series of comparison ABX tests, where one was done with recordings of std. wiring vs. bi-amping and the other was done direct, without recording. He did previously run ABX tests with recordings he made of his speakers with and without silicone rubber pads. But he doesn't know if recorded comparison of std. vs. bi-amping results in a valid test or not.… It's impractical for me to do a blind test, given the time and effort required to change from bi-amp configuration to normal. An ABX with enough repetitions to prove audibility would take dozens of changes, each of which takes longer than ideal for our short audio memories.
Finally, ABX tests or blinded non-ABX tests are convincing only when done with larger numbers of listeners. The OP did his tests with only himself as the listener. He may have repeated the test a number of times, but statistically N=1. That ain't statistics in any sense of the word.Recently in my previous experiment, it was shown that recorded speaker outputs can be used in an ABX test to demonstrate an audible difference for a change of speaker feet, so I wanted to see if this ABX method would also work here. I recorded the output of my Revel Salon2 speakers playing music in stereo using a pair of high quality cardioid microphones (Shure SM81), each mic 2' in front of the tweeter's logo.
I'm not sure any of your criticisms hold water. Certainly a single person can do enough trials if truly blinded to determine if they can or cannot hear a given thing.The OP admitted he didn't do a blind comparison test.
Instead, he made recordings made with standard wiring and bi-amping, and compared them in an ABX manner. Unfortunately, he didn't run a series of comparison ABX tests, where one was done with recordings of std. wiring vs. bi-amping and the other was done direct, without recording. He did previously run ABX tests with recordings he made of his speakers with and without silicone rubber pads. But he doesn't know if recorded comparison of std. vs. bi-amping results in a valid test or not.
He wants us to believe recordings provide similarly equivalent results to non-recorded results in his bi-amp experiment, but he didn't provide any info or data from "previous experiments" that would demonstrate that.
Finally, ABX tests or blinded non-ABX tests are convincing only when done with larger numbers of listeners. The OP did his tests with only himself as the listener. He may have repeated the test a number of times, but statistically N=1. That ain't statistics in any sense of the word.
I am more or less in line with you....It's within measurable statistical variation, I'd say.
So long as you are not using telephone wire, my guess is "bi-amping" is a myth designed to sell more overpriced cables.
But then again, I cannot remember where I left my RF ear-trumpets, so I may be wrong.
I used headphones. It's just a flawed recording where the rumble can give it away, at least that is what I heard. I don't think you can get anything useful from this; I doubt that any microphone recording would get at whether bi-amping makes a difference.I checked with my stereo setup. With just sub on (stereo amp for speakers off), indeed I could sense the rumble with regular clip. However, once I turned on my stereo amp and my speakers start playing, the rumble was masked and I can't sense the rumble. Maybe you can sense the rumble with everything playing, but I can't.
: )
It’s all one big system. The speaker cable companies want to sell cables, so advocate for bi-wiring. The speaker companies give them the means to do that, and it gives them an extra marketing opportunity to show of the dual or triple terminals some more that the magazines tout as the best thing since sliced bread. The thing is: speakers with dual terminals sell better than with single terminals. You can’t sell a respectable speaker without at least dual terminals. So yes, there is a lot of incentive to put these thing in!Why would a speaker company place bi-amp connections on a speaker to sell cables that they do not produce and have no financial stake in?
I don't belive there is a sonic difference, but selling (another) company's speaker cable is not the reason.
I assume you are talking about the recording? What I heard when doing the ABX, is that the track with less rumble sounded much better, with clearer mid and high freqs. Because the rumble wasn't there to muck it up. So even if you think you are only concentrating on the high end, the rumble still makes the difference.As I mentioned the differences were in high frequencies, and that's what I listened for. I mainly relied on one note from the violins/violas.
Good job, and thanks for doing this investigation. It does look like this particular 2Lhaydn recording has a rumble that you can detect.I used headphones. It's just a flawed recording where the rumble can give it away, at least that is what I heard. I don't think you can get anything useful from this; I doubt that any microphone recording would get at whether bi-amping makes a difference.
I don't mind trying, but if there aren't any cues from room noise pickup then I'm sure I won't pass. Is your posted ABX result for the whole track or the 8 sec version? If not the 8 sec version, do you mind doing it again with the short segment so we are all doing the same thing?Good job, and thanks for doing this investigation. It does look like this particular 2Lhaydn recording has a rumble that you can detect.
However, as I mentioned in my original post, I did my ABX using a different string quartet that I'm familiar with, which corresponds to the ABX log I posted. I didn't post that because the original source is not free.
I checked whether there's a rumble there. Here's how it looks in Audacity after 100hz 48db low pass and normalized (bottom is "haydn33 biampedNOT.flac" which is normal):
View attachment 199453
To compare, here is the same for the 2L file, which shows the rumble
View attachment 199451
so I don't think the same issue exists on the recordings I ABX'd. The entire recording is too large to post but I was distinguishing by listening only to the first couple seconds anyway, so here's a clip of the first 8s.
Why would a speaker company place bi-amp connections on a speaker to sell cables that they do not produce and have no financial stake in?
The OP admitted he didn't do a blind comparison test.
Instead, he made recordings made with standard wiring and bi-amping, and compared them in an ABX manner. Unfortunately, he didn't run a series of comparison ABX tests, where one was done with recordings of std. wiring vs. bi-amping and the other was done direct, without recording. He did previously run ABX tests with recordings he made of his speakers with and without silicone rubber pads. But he doesn't know if recorded comparison of std. vs. bi-amping results in a valid test or not.
He wants us to believe recordings provide similarly equivalent results to non-recorded results in his bi-amp experiment, but he didn't provide any info or data from "previous experiments" that would demonstrate that.
Finally, ABX tests or blinded non-ABX tests are convincing only when done with larger numbers of listeners. The OP did his tests with only himself as the listener. He may have repeated the test a number of times, but statistically N=1. That ain't statistics in any sense of the word.
Can you drop both your recordings into Deltawave? It will do a null test of them and provide other information. You can download it for free here:Good job, and thanks for doing this investigation. It does look like this particular 2Lhaydn recording has a rumble that you can detect.
However, as I mentioned in my original post, I did my ABX using a different string quartet that I'm familiar with, which corresponds to the ABX log I posted. I didn't post that because the original source is not free.
I checked whether there's a rumble there. Here's how it looks in Audacity after 100hz 48db low pass and normalized (bottom is "haydn33 biampedNOT.flac" which is normal):
View attachment 199453
To compare, here is the same for the 2L file, which shows the rumble
View attachment 199451
so I don't think the same issue exists on the recordings I ABX'd. The entire recording is too large to post but I was distinguishing by listening only to the first couple seconds anyway, so here's a clip of the first 8s.
Very nice.I used headphones. It's just a flawed recording where the rumble can give it away, at least that is what I heard. I don't think you can get anything useful from this; I doubt that any microphone recording would get at whether bi-amping makes a difference.
View attachment 199445
I don't mind trying, but if there aren't any cues from room noise pickup then I'm sure I won't pass. Is your posted ABX result for the whole track or the 8 sec version? If not the 8 sec version, do you mind doing it again with the short segment so we are all doing the same thing?