KEW
Audioholic Overlord
How do you use active bi-amping to help with room modes?
"Let our rigorous testing and reviews be your guidelines to A/V equipment – not marketing slogans"
KEW
Audioholic Overlord
Alex2507
Audioholic Slumlord
I know that I've crossed some line where being rational isn't required.
The best part of all this for me has been figuring out how to use my rec'r's memory to lock in an attempted calibration and then lock in an auto set up using YPAO so I can switch back and forth.
I had no idea that I would prefer YPAO by such a wide margin. Thanks for the article, Steve.
The best part of all this for me has been figuring out how to use my rec'r's memory to lock in an attempted calibration and then lock in an auto set up using YPAO so I can switch back and forth.
I had no idea that I would prefer YPAO by such a wide margin. Thanks for the article, Steve.
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fmw
Audioholic Ninja
Thanks. No I'm not but I'm going to take a little vacation from the site and I wanted to leave as little conflict as possible behind.
RichB
Audioholic Field Marshall
You can also use something like the MiniDSP:
https://minidsp.com/products/minidsp-in-a-box/minidsp-2x4
and a program like REW and a mic to PEQ the bass frequencies.
YPAO works with or without bi-amp.
- Rich
AcuDefTechGuy
Audioholic Jedi
I want to adjust only the bass without using tones or room EQ, not mess with the midrange & treble.
Sent from my SAMSUNG-SM-N900A using Tapatalk
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PENG
Audioholic Slumlord
No that was not my intent at all. I truly want to give a few examples of reasons why passive biamping could make an audible difference but not always.
I agree with what you are saying but that has little to do with the examples I listed. You can keep everything the same so the only variable is single amped and biamped, but if the speakers used in the comparison test has very well designed crossovers and the speakers as a whole are of very good quality then biamp will not likely bring anything to the table. Conversely if the speakers in use are of relatively poorer design than biamping would probably help by lessening the interaction of the crossover and and amplifier/speaker feed wires. I know this one is complicated to understand and I have read a few articles that tried explain the details. Below is one example:
http://sound.westhost.com/bi-amp.htm#passive_xovers
The article covers both passive biamp, biwire and active biamp so it is a long read; and need to be read carefully to void being confused by the multiple scenarios covered.
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PENG
Audioholic Slumlord
But you still have more than enough fully differential amps for passive biamp vs single amp tests. I am sure your RBH speakers are revealing enough for the job. Are the bass drivers driven by built in (active) amps? Seriously it would be nice if we can get together one day to do some tests to settle this often debated topic.
AcuDefTechGuy
Audioholic Jedi
I've talked to Shane Rich and this is my limited basic understanding.
The RBH flagship towers (both modular like T2, SV831/1212, & 8T and single cabinet like SX-8300 & SV-6500) are designed so that when the metal jumpers are removed, the bass is completely separated from the treble/midrange; they become 2 completely separate speakers - like a separate monitor with internal crossovers + separate passive subwoofer without internal crossovers. So the treble/midrange has the crossovers, but the bass/subwoofers don't have crossovers.
The SV831/1212 tower is a SV831 monitor with internal crossovers and a SV1212 passive subwoofer without internal subwoofers.
On my T2, the T1 monitor has crossovers for the tweeters + midrange, but the 1010 subwoofer does not have crossovers for the dual 10" woofers. The dual 10" woofers do not have any built-in amps or crossovers.
I do use all ATI amps for the five T2 towers. Each T2 tower gets 1 amp for the 3 tweeters & 4 midrange drivers (passive because of the internal crossovers) and 1 amp for the dual woofers (active because there are no internal crossovers).
Actually, each T2 tower could be QUAD-amp: the tweeters & midrange drivers can be passively bi-amped and the dual woofers can be actively bi-amped.
Man, I could have used 4 amps per tower x 5 towers for a total of 20 amps of ATI!
Oh yeah, my towers are so power hungry and I really need to use 20 amps.
I wonder if Gene Quad-amps each 8T tower.
RichB
Audioholic Field Marshall
If you are splitting the preamp out, then the end that goes to the bass drivers goes into the MiniDSP and out to the amp. There is an A/D/A conversion though. The non-Dirac units are reasonable quick, 2 to 4 milliseconds.
Filters can be created that adjust the bass only. Measurement with REW is easy and an elegant solution, but it definitely has a learning curve.
- Rich
AcuDefTechGuy
Audioholic Jedi
Yeah, you could do all that A/D/A conversion & MiniDSP with the learning curve.
But like Irv says, when your system already sounds mellifluous, you're not exactly chomping at the bits to do any of these things that you don't need to. You want just sit back and just enjoy if your system already sounds awesome and you are 100% happy. Why would I want to mess with A/D/A conversion that could screw up my amazing sound?
When I could just simply actively control the level of my bass without doing any of that?
IMO Audyssey Dynamic EQ does a spectacular job with the Bass EQ. I have been told by another forum member that the RBH SA-500DSP may perhaps do a better job or at least improves on Dynamic EQ. But right now I am 100% happy with DEQ, I'm not chomping at the bits to go through more learning curves.
But maybe I see your point. If you could actively bi-amp the bass, you could do miniDSP to EQ the bass, if you prefer it over something like Audyssey Dynamic EQ.
But if you could only passively bi-amp, you could not do miniDSP, which is why I think passive bi-amp isn't as functional as Active bi-amp, which goes back to the topic.
If you already have amps laying around, there is no harm trying out passive bi-amp. But don't spend $1000 or $2000 on amps thinking that somehow PASSIVE bi-amp will significantly improve the sound of your speakers. Spend that money on new speakers, subwoofers, or electronics (subwoofer EQ, Audyssey XT32/DEQ, etc) or something else important in life.
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Alex2507
Audioholic Slumlord
I think you mistook Swerd slamming RichB to apply to yourself.
Now I know this doesn't count as active bi-amplification but the rec'r's xo for the sub pre-out has a selectable xo point and it's own channel trim. I haven't seen any glaring differences using various xo points but the control is there over the balance of low bass if not the nature of low bass. I have a Behringer DEQ 2496 kicking around still that I haven't learned to use. Future me will have no trouble implementing that toy (much sarcasm).
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PENG
Audioholic Slumlord
You are right, he (fmw) somehow thought he was RichB, and RichB probably thought he was fmw, go figure
! Now you are going to get RichB riled up so Swerd is going to get it..I also feel Steve is harder on fmw and easier on RichB because of his moderator head, iow he may be affected by the "tone".
Politics aside, funny I was also thinking about the Behringer thing, though I think I am going to get the dBX223 (something like that) just so I can try the different crossover points on my LS50/E15HP combo. I agree with your concept that such arrangement is not unlike passive biamp. I would say at least equivalent to 75% active biamp and the other 25% will make it superior. Using the variable crossover, REW and a good EQ I should be able to flatten the curve to much greater extent without spending a fortune of high end REQs such as Dirac.
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Alex2507
Audioholic Slumlord
Actually I am 100 % passive bi-amping the signal above the selectable 80 Hz xo. I'm not sure if you wrote passive instead of active. Either way, I'm glad I went to the trouble. I'm suggesting that the active xo in the rec'r lends itself to making the whole system closer to active ... tri-amplification if you will.
Irvrobinson
Audioholic Spartan
I doubt it, more like drawing a general conclusion from a few data points. In my case, fmv's remarks are especially annoying because they assertively use a bit of science to draw a general conclusion from a couple of marginally related data points. I really don't care how many people post that subjectively they hear differences, because everyone knows those posts are tantamount to simple opinions. fmv is incorrectly using some blinded testing to support a point that many of us happen to believe in, which has the net effect of cheapening the argument against passive bi-amping. A reasonable observer could conclude that fmv's arguments prove nothing, so perhaps there might very well be value in passive bi-amping with extra AVR channels for their speakers. I certainly agree that is quite unlikely to be the case, but using a bogus argument against it is bad form.
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PENG
Audioholic Slumlord
Thanks, fixed it, active is was..
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PENG
Audioholic Slumlord
We really don't know how he did his tests do we? I just re read some of his posts and I have to agree he did make the conclusion that passive biamp would not make audible difference based on his tests. Rich also did seem to think in his setup there was a difference so others should try, though he did not draw any conclusion that everyone should hear a difference in their own setups. I hope I am allow to modify or remove my post.
I still think we are too hard on fmw, well, not me, and I happen to believe depending on the gear one has, passive biamp could yield audible difference, though more often not.
Swerd
Audioholic Warlord
Thanks for clarifying that
. I readily admit I took your list of examples and ran with it to spell out (or re-spell out, as I can be a broken record on the subject) what is sorely lacking in nearly all blind listening tests I've known.And yes, I was annoyed at RichB's comments about bi-amping. I doubt if he really intends to make broad scientific conclusions, but he took one (and only one) case, perhaps an atypical exception or perhaps an artifact of unintended testing bias, and trotted it out as the exception that proves the rule. It's easy for me to take his comments as a direct challenge to my dearly held principles of scientific method & thinking.
FMW – I never meant that you were a troll. Far from it. I'm sorry if you misunderstood my posts.
I've read that long Rod Elliot article in the past, and I re-read parts of it this morning to refresh my memory. (I am not formally trained in electronics or physics, but I am trained in a different branch of science, molecular biology. Unlike other sciences, it is entirely experimental and many of us actually look down on arguments based on theories alone. We usually bring out stories about well known scientists who talked themselves out of doing experiments that might have won them fame & fortune if they had ignored their doubts and pushed ahead. I've known two such people.) Anyway, my own bias is to get all the data and info you can, and then try and explain the results. And you should never ever fall in love with your own ideas. Instead you should try to prove them wrong. I doubt if RichB sees it the same way.
Back to Rod Elliot. His article provides in my opinion largely theoretical reasons why passive crossovers are a poor idea in audio. When I first read it, I took his conclusion, as gospel, that all speakers should have active crossovers upstream from amplification. I now think that is overstating things. He shows reasons how some passive crossovers create problems that can and should be avoided. Certainly the home audio industry has largely ignored his opinions. I think the practical & economic arguments against active crossovers carry equal weight to his electronic arguments for them. In the future, as prices and fashions change, that balance might shift.
Steve81
Audioholics Five-0
One of the dangers associated with making a claim on the internet, but not backing it up in any meaningful way (test methodology, associated gear, detailed results...). Still, fmw claims to have more experience in bias controlled testing than Floyd Toole & Gene, so I'm sure that's merely an oversight on his part.
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