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Audible Component Differences...A Nousaine Story (1 Viewer)

Michael R Price

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Robert,

How does the active bi-amping sound compared to a normal setup? I remember having a discussion with Brian Cheney and he said he didn't like active crossovers. What he was saying made sense but didn't really apply to me and my DIY stuff, so I never gave it a second thought. But it would be neat to hear what active bi-amping does to VMPS speakers. Is the active crossover specifically designed to work the same as the passive filters in the speakers?
 

Yogi

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On the note of active bi-amping. Does it really improve sound? Would just having straight wired a more powerful amp gotten you there? Furthermore could you pick out a biamped system from a straight wired system when both are operating in their linear regime, in a DBT to any level of statistical significance? Also what are the kinds of differences in sound you hear with your bi-amped speakers that you wouldn't have heard with say a 750W crown amp straight wired to your speakers? Sorry about these questions, but I am curious as I hear a lot of conflicting things about bi-amping and its supposed merits.
 

RobertR

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I don't know why Brian would say that to you, Michael. Maybe he was talking about crossovers not specifically designed for the speaker. Here's a picture of the active crossover used in my system:

http://vmpsaudio.com/st3pic.htm

You can see that not only does he use an active crossover, he specifically designed the speaker for it. I don't know how different it would sound without the active crossover. I bought the speaker as it was designed, with the ribbon, crossover and everything that goes with it. The bass is incredible, and obviously doesn't have to share power with the mids/highs.
 

Mike Keith

Second Unit
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Jan 24, 2002
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To expound on what Robert said about Active Bi-Amping.

It's been my experience that Active Bi-Amping has the biggest impact in sound quality of any change that I have ever made. I have switched my entire DIY system to all active after I discovered the incredible differences. The dampening increase by having your Amp output directly coupled to your drivers, IMO, makes for a drastic improvement in control over the drivers.

I can drive an active loudspeaker easily to ref levels without straining the drivers, or you ears. With the passive networks the drivers would severely distort well before ref levels. The independent level control over each driver is also a big plus for matching in-room, not to mention much less wasted power. I will probably never have a passive component in my main system from this point on.
 

Michael R Price

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I agree on why active crossovers are better. But I don't just mean for crossing a subwoofer over to speakers. :)

I asked "What does Brian Cheney think of active bi-amping?" and he replied:

"Not as much as you would think.

The purist form of biamping is passive, with two amplifiers driving the internal crossovers of the speaker system. This allows you to use different kinds of amps on bass and mid/treble, and (if the amps are integrated or have level controls) control the outputs of each section relative to one another.

Electronic crossovers are best restricted to the bass and should use 24dB slopes with the drivers electrically in phase. I don't care for the ringing, noise and distortion added by the exo to the mid and treble bands, where high quality passive parts can be used. The TRT's are a good example of a very high quality signal throughpath. We offer them because of sound quality and admit they are very expensive. They do offer a step up in quality from the Auricaps, as the Auricaps do over the stock Axon/Solen polyprops. Remember the TRT's were rejected by the manufacturer of a $125,000pr speaker as "too expensive". The Auricaps aren't cheap either and require numerous trim caps (due to their 10% tolerance and my fondness for trimming to four decimal places). "
 

RobertR

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Michael,

That's exactly the approach Brian uses. The signal to the mids/highs is not run through the active crossover. What I take his statement to mean is that it explains why his approach is better than that used by others. :)
 

fletcherS

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May 18, 2004
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Hi, I'm new into this home theater thing, after coming back from a real basic setup in the 90's, I've decided to create a pretty good system, with good interconnects and all. Probably a really dumb fact that I've tested myself though, is the digital interconnects vs the crappy phono cables that came free with the DVD player. I set up my Marantz SR7300 with optical connection for DVD channel, and the phono connection labelled as CD to the same DVD player. Then I played Evanesence's "My Immortal", sat and listened closely. I didn't even need to listen too hard. As I switched from digital to phono channel, I was taken back by the HUGE difference. Mind you, I'm not a seasoned audiophile or mucisian, but I can definitely tell the great disparity between sound quality. The phono connection made the vocals seem far away and muted, with even a little bit of hissing coming out. The piano lost all it's qualities and I couldn't really tell apart the notes of the chords being played (I could for the digital connection). Next, I did the same for RGB vs composite video, and surprise surprise, the picture quality was worlds apart too. The composite signal was messed up, and I could even detect shaking images from my panasonic plasma monitor. Imagine sitting through 3 hours of shaking images from LOTR! Suffice to say, digital interconnects make LOADS of difference in the set up (very contrary to the quoted Nousaine story, where digital vs analog made no diff), and it was worth every penny of the $100 or so that I spent on optical and RGB interconnects. If you've got a good system, why spoil it by using crappy cables?
 

Kevin C Brown

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OK, I'll bite. :)

1) When you did the optical vs RCA analog cable test, did you make sure that speaker output levels were matched to within 0.1 dB? I.e., it is a well known psychoacoustical fact that something just a hair louder than something else *will* be perceived as "better".

2) When you do that test, you are switching between using the DACs in the player vs (presumed) receiver. There definitely can be audible differences between DACs. Has nothing to do with the cable.

3) For the RCA cable case, could you run "analog direct" mode on your receiver (pre/pro) ? Otherwise, you're probably encountering A to D and then back again conversions, which can also worsen the sound quality.

3a) Was the bass management in both cases the same?

4) RGB (component?) vs composite doesn't necessarily have anything to do with cables. RGB video simply has more bandwidth than the composite video.

5) RGB is still analog. DVI or HDMI is digital.
 

fletcherS

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Are you saying that all things equal, digital vs. analog audio connection makes no difference?

From my set up, it wasn't about loudness. Even as I turned up the volume on the analog channel the vocals were louder, but were airy and choked. The highs and mids were sort of muted, and it's easy to tell with the female vocals. When I turned up the sound, the bass came on, but the vocals was still comparatively muted. That is to say, from a very amateur point of view, the highs vs lows ratios was affected when I switched channels.

Now I don't know anything about A to D switching, but I did use source direct stereo.

I switched using receiver source, not using player DAC.

Everything else was untouched, including Bass management.

Ps. I just tried it again.. same results..

thanks.
 

Kevin C Brown

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No. What I am saying is that you are attempting to draw a conclusion that might not be true. There's a lot more potentially going on than just "analog" vs "digital".

And just to confuse you even more, a lot of people prefer the digital coax connection over optical. :)
 

fletcherS

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May 18, 2004
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OK, granted, my experiment might not be perfect. But I did this test a long time ago, and just confirmed it. When I did it I wasn't prejudiced by having an a priori conclusion. I was a little green at that time, and I wanted to find out which connection will give me better sound, not expecting too much from digital connection (I figured it just carried "extra" DTS or dolby codes for surround sound). My analog interconnects were the free ones that had really thin black cables, and red, white and yellow connectors.

But I find it quite uncanny that real crappy throw away analog connection would be exactly the same sound-wise as proper digital interconnects. Has somebody done a scientific study measuring the output signal using computers graphs? I'd like to know if they found a difference.

another question follows then, how do reviewers "rate" speaker cables, mains leads, interconnects etc, if they are truly not different sonically? Seems to be just random guessing? How would you justify several reviewers arriving at a converged conclusion about a particular cable?

thanks.
 

Michael R Price

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Robert,

I was proposing that the same benefits of active crossovers for the subwoofer to main speaker can also be realized by separating each section of the speaker (woofers, tweeters, etc). I know it's a dumb idea to argue with Brian Cheney, but I still can't agree with his viewpoint. Brian explained the "ringing, noise and distortion" as artifacts of cheap commercial crossovers that no sane person would use in a hi-fi system - most have cheap IC opamps and fixed, widely spaced filter frequencies and Qs. The successful active speakers, such as Linkwitz's, use high quality filter electronics designed to suit the drivers. As far as measured performance is concerned, it doesn't cost much to get small signal resistors/capacitors/opamps that work as well as Auricaps or TRT's. The only disadvantage I see is the cost of multiple sets of amplifiers.
 

Chu Gai

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First let me say hi, fletcherS, welcome to HTF. Hope you stick around for a while.

Perhaps I've misunderstood your 'experiment'. I'll summarize it as I understand it. You've got a CD player or something like it. You ran analog from the player to your receiver. You also ran a digital output from the player into your receiver's digital-in. You then compared the two scenarios without touching anything. If so, here are my comments.

Has somebody done a scientific study measuring the output signal using computers graphs? I'd like to know if they found a difference[/b]
Well if you go back and read the first post in the Audible Component Differences...A Nousaine Story thread you'll find precisely that. In order to validate your observations you'll need to do a couple of things.
Burn a CD with test tones and use a multimeter at the speaker terminals to ensure under both scenarios that the levels are the same. Pay attention to channel imbalances. If there are any find a way to make them the same. Then repeat your test with no one knowing the difference. If there's still a difference, you'd then need to ensure that both scenarios had the same frequency response. Again, that can be determined by burning selective test tones covering a frequency range and the multimeter. Of course it is assumed that you never know the identity of what is being tested.
 

RobertR

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I don't disagree with what you're saying, Michael. I'd have to hear what a speaker sounds like using that approach, though, and I'm not inclined to trade in my current pair. :)
 

Wayde_R

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Fletch and Kevin

Reading Fletches test maybe I misunderstood. What exactly was Phono? Were you using a phono input on a receiver? Or are you just calling the analogue RCA cables phono? If you're using a phono input there are certainly grounding issues, but it's been a very long time since I've seen phono on anything.

I would expect a noticeable difference between analogue vs digital delivery from the playback device. Digital is always superior. Not only are dacs in a receiver likely better than the dacs in the playback device. If you believe that the impedance of the cables makes a difference, digital signals are not affected by impedance the same way as an analogue signal. As long as all the bits make it to the destination you have a perfect signal, no noise or loss.

Most receivers will convert your analogue signal to digital, process it (you have things like DSPs and Dolby Digital that only work in digital) and then reconverts it to analogue again before sending it to the amps. Conversion back and forth from analogue to digital and back again is a sure way to lose resolution. It's no Jedi-Voodoo mind trick to see this graphically illustrated in a superior picture when using DVI vs component.

Now please, share a toast to my first born.:)
His name's Bruce
 

Chu Gai

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Wayde, that's a good looking kid you've got there! The early years, for that matter all the years, are good ones. Even the time I took my first born into the tub with me and he took dump that covered the water. Many, many congratulations.
 

Michael R Price

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Jul 22, 2001
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Robert, that's cool... I can see why you're not looking anywhere else. I should be completing my designed-from-scratch active crossover for Kit281s (2-way towers... much smaller than yours) this fall. I hope to avoid some of the things people (like Brian Cheney) complain about with regular electronic crossovers. The current passive design has been well regarded for years, and it'll be interesting to see how mine compares, with the help of multiple high quality amplifiers. :)
 

Wayde_R

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Thank you Chu... the pic is many months old but it is beer. I was enjoying a fine Stella posing as a silly dork might (it comes natural to me).

I re-read the Nousaine article. DUH! :b

I get it now. I was simply re-stating conventional wisdom, sorry. Suffice it to say I will still use digital outputs whenever possible. However I do not doubt the stories authenticity nor inconsistent results if I were to DBT myself at home.
 

Yogi

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:emoji_thumbsup:

Nice kid you got there. How old is he now? I have a 11 mo old thats a pleasure to watch as she tries her first steps.
 

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