[neils]

Question is 2-fold for Audyssey XT32 experts here. But a little background on my setup to understand my questions. My LCR channels consist of speakers with powered subs (built-in amps), that require an RCA signal from the prepro. Since I hate using Y-adapters, I plan to use the RCA outs of the prepro for my power amps feeding the passive part of those speakers. And then use the XLR outs of the prepro into an active XLR-to-RCA converter and feed the active subs of all 3 speakers.

So that leads me to question #1 . Will Audyssey XT32 process both the XLR and RCA LCR signals as one where both connections are used ? My guess is yes, since it will simply shoot out pink noise to determine if anything is connected to those channels, and will hopefully apply the same processing to both XLR and RCA outputs for each channel.

Now onto my 2nd question with background first. I am running 4 Clark Synthesis Gold shakers in my couches, driven by 2 pro audio amps (Carver). I have a pro XLR distribution unit that takes an XLR in and feeds 4 XLR outs to these amps. I do not want or need Audyssey processing on this signal, the shakers do not need to be room corrected.

So my 2nd question, if I am using an actual sub on the RCA out of the prepro, I intentionally leave the XLR disconnected to the shaker amps, run Audyssey so room correction is applied only to the sub on the RCA, then connect the XLR cable afterwards. Will that XLR out on the prepro be functional post XT32, with an unprocessed signal ??

I realize this is not your typical XT32 or prepro setup, but I need to wrap my head around how Audyssey will handle this.

Thanks guys !!

Neil

 

[henrich3]

My impression is that your cabling scheme is more complicated than it needs to be. It's my belief that speakers designed with separate LFE Input jacks do this for marketing purposes rather than audio quality. What speakers are you using? If your speakers have internal crossovers that can direct the low frequencies from the speaker cables to their built-in subs, why not omit the LFE cables to your speakers?

That said, Audyssey doesn't care how you cable up your speakers. It pings each speaker and will try to flatten the response. If your pre-pro has both XLR & RCA jacks for each channel, they will both carry the same Audyssey-corrected signal.

If you want your shakers to receive an uncorrected input, the best way to do that is to use the LFE output from your source (eg. Blu-ray player). If you don't care for the limitations involved with going that route, you could get an external sub eq (eg. Anti-Mode), EQ your sub with that, then run Audyssey. Audyssey's low frequency correction should be minimal if this were done. This would involve using a Y-cable however, which you said that you hate. Not sure why...

 

[Glimmie]

The XLR and RCA jack should have exactly the same signal as far as any processing goes.

However in properly designed gear, the RCA output is a -10 to 0db and the XLR should be at +4db which is quite a level difference. Now some "high end" consumer gear runs the XLRs at non standard levels so that can be a trap.

So no, it's doubtful you can have two processed different feeds between the XLR and RCA jacks unless this is specifically supported.

P.S. there is nothing wrong with Y cables. They are sonically transparent to spite audiophile fokelore. If you don't like the mechanical mess, that's another issue but they will not "sound bad".

Also running balanced XLR to your subs is the best way to avoid ground loop hum.

 

[neils]

To henrich 3, there is no other way around it, no marketing scheme involved, just some brilliant engineering for what is considered one of the best HT speaker rigs ever made (noticed I said one of and not THE, there are many others). The Polk Audio RT5000 rig, which consists of the RT3000 fronts, which is a 2 cabinet design, with the bottom part being 2 powered (300w) 8" subs. The 2 cabinets were designed to work together as a single speaker. I am not feeding the bottoms with an LFE signal, I am feeding them the same front L or R signal as the tops. Hence why I need to use both outputs on my prepro. The RCA going to my power amp to power the tops, and the XLR going to a pro converter to RCA then onto the bottom active subs.

So that is why I was asking if Audyssey will apply XT32 processing to both the RCA and XLR outputs at the same time, considering them as one. But logically thinking about it, it uses pink noise, and should pick up both outputs as 1 speaker.

Glimmie, I am familiar with the differences in RCA and XLR levels, did pro audio for many years (still tinker from time to time). That is why I am using a pro solution, to ensure the conversion of signal levels is accurate, APHEX 124. I know levels are matched, and for whatever mental reason, am not convinced Y adapters are just as good. I could have the best audio cable money can buy, then I stick 2 of them onto a $50 Y adapter from a reputable company, not sure if I am degrading the audio going from one type of wiring to the next. Not to mention that I am also not convinced that the voltage levels will be the same coming out of both ends of the Y. With the APHEX, I can control that level, knowing it is -10dB to 0 reference.

 

[Glimmie]

and for whatever mental reason, am not convinced Y adapters are just as good. I could have the best audio cable money can buy, then I stick 2 of them onto a $50 Y adapter from a reputable company, not sure if I am degrading the audio going from one type of wiring to the next. Not to mention that I am also not convinced that the voltage levels will be the same coming out of both ends of the Y. With the APHEX, I can control that level, knowing it is -10dB to 0 reference.

Well with modern gear, a Y cable should not cause an audible level drop. You might be able to measure some HF loss in the 15-20khz range due to the increased cable capacitance and to some people that could be audible.

Now older pre 1970s pro audio gear did utilize power matched line level systems. 600ohms to 600ohms matched. So here a Y cable could (would) cause a 3db drop with two 600 ohm loads on it. But for this very reason professional audio system went to voltage matching in the early 1980s. Once you get over about 200khz, like video and RF, power matching still rules.

But your solution is certainly "doing it right"!

 

[jaddie]

Well with modern gear, a Y cable should not cause an audible level drop. You might be able to measure some HF loss in the 15-20khz range due to the increased cable capacitance and to some people that could be audible.

Not even that, if you look at the source impedance of the output. It would take a long cable to get enough C to roll of the high end.

Y cords have lower noise and less distortion than the Aphex. The subs should have input level controls, right?

The advantage of the Aphex would be the prevention of ground loop noise, but that assumes balanced cables up the the Aphex located near the speakers.

There's no reason any prepro would have a processing difference on the XLR output vs the RCA.

 

[Glimmie]

Not even that, if you look at the source impedance of the output. It would take a long cable to get enough C to roll of the high end.

Y cords have lower noise and less distortion than the Aphex. The subs should have input level controls, right?

The advantage of the Aphex would be the prevention of ground loop noise, but that assumes balanced cables up the the Aphex located near the speakers.

There's no reason any prepro would have a processing difference on the XLR output vs the RCA.

Yes I certainly agree 100% but I was just offering a slight benefit of doubt as not to start another cable debate.

And I have seen some piss-poor balanced output implementations on very expensive consumer gear. Meaning a gold plated XLR connector literally wired in parallel with the RCA jack! So in this case the output impedance is a crap shoot.

After all, any good audiophile knows the XLR only sounds better because it's an XLR connector. The balanced drive circuit makes no difference in true high end gear.