The official "Theta" thread - Page 153

It is to make an objective determination of what might be happening that causes the difference in subjective quality.
No. If I had a CBIII the mystery would have been easily resolved with some simple test gear.
The test reduces the need to guess. I read John B's quote, and it looks to me like he is carefully avoiding explaining that the stereo mode departs from his description of Matrix: >>the front left and right channels are as close to Analog Direct mode as possible<<, so I do not expect pressing the point would get very far.

I see that the issue regards digital sources, not analog. In that case, the same test can be done but some particular source material must be used. A test disc with signal only in one channel, like Alan Parson's Sound Check II CD, track 34.

If no one wants to do the test, that's fine. I just think part of the fun of this hobby is in understanding what makes two ostensibly identical 2-ch playback modes sound so different.

I am wondering myself. What I am hinting is that the signal from the description of the Matrix mode will not be available at the digital outs and the test not worthwhile. John Baloff likely can offer answers. My bet is that Matrix mode is adding some sort of processing to the stereo signals.

No one listens to digits. If it is audible, then it is audible from the analog outputs.
Easy to find out...

Roger, my system is down (a vinyl-related mishap with the Thiel speakers that requires rebuilt of the subwoof drivers ) but I could give this a try when it's up and running.

1. I only have digital going into the Theta (all analog signals going to CJ tube pre). Could you revise the test for digital, as mentioned above? It is the test that is relevant for me and most people on this forum.

2. I tried to decipher your testing conditions/parameters but couldn't. Would you please explain, in above test:
A. If there is audible signal on R speaker in any particular mode, stereo or matrix, what does that mean?
B. If there is no audible signal on R speaker, what does that mean?

I didn't say "listens to." I said "available at the digital outs." Many do have Digi out cards.

If you are going to do this, I believe the proper way to "mute" speaker channels is to go into CB speaker config and set every channel to "off" except the R channel. Note that per original advice I received on using this mode for 2ch listening on a digital source input, instruction was to go into speaker config and turn off all channels except L/R. I decided to leave Sub1 enabled since I use my sub for 2ch.

For your questions on 'what does this mean' given potential differing results, the only credible answer source is Theta. Outside of that would just be speculating or guessing, for what that's worth.

What would you propose to do with a digital output in this test, if not listen to it?

Wow, if that works as I hope, it would make such testing very easy. In most speaker configuration systems, if for example you tell it there is no center speaker, it not only leaves the C output silent, but it reroutes the C signal into the L/R speakers so it remains audible. This downmixing is correct in normal circumstances, and even for the Matrix mode you enjoy. But it could disrupt the test I am suggesting if setting the various speakers to off causes any change whatsoever in signal handling.

So, to ensure this is not happening, it is best not to inform the system any speakers are being removed. Just disconnect all but the right speaker.
Yes indeed. The same test can be done with a digital source. It has to be a case where there is signal present in only one channel, preferably a 2-ch source. One that I have on hand is Alan Parson's Sound Check II CD, track 34. Another is the earlier Sound Check CD, track 2. These are available as online downloads for burning on CD-R. Or, if you have the AIX Blu-ray test disc, it has a PCM 2.0 channel ID test signal that will work fine via either S/PDIF or HDMI. Any such test signal will work as long as it is purely in the Left channel.
When you play the L-only signal, and the L speaker is disconnected, one would expect to hear nothing. If you hear nothing, there is no signal processing that would affect the spatial properties of the channels. If, OTOH, some of the source audio is audible in either the Stereo or Matrix modes, that could tell us something about why they sound different. The one with the crosstalk is not pure stereo. If no crosstalk is heard in either mode, this eliminates one of the possibilities, but does not assure they are treating the source audio identically.

I did the test using an EMI test CD. In Matrix mode a left channel only signal only plays out of the left speaker; a right channel only source plays only out of the right speaker.

Thanks. So it's dead silence in the "off" channel?

How does the Stereo mode do? Same?

Yes, Stereo is the same.

I did some A-B listening between Stereo and Matrix; the differences between the two are subtle and I can't tell if a blind test would be the same but the Matrix mode seems to have a shelf EQ set. It's a little smoother in the high end. Where the Stereo mode has somewhat more sibilance. Like I said this was a subjective listen for about an hour on Jackson Browne's Solo Acoustic 2 disc. YMMV

Thanks very much for your help with this. That pretty much eliminates the possible issue of the Matrix mode adding any subtle processing the the L/R signals while going about the business of creating the C or Surrounds.

The EQ difference, or something like that, would be the next place to look. If indeed EQ is a factor, that would be easily measured. If someone has REW (and appropriate audio interface for the PC) it is a snap, at least for an analog input.

Or a volume difference, Roger? Dunno if that's a possibility in this scenario, but it's one of the usual suspects and an easy check.

Not if the "test" is a subjective one. Occam's razor comes to mind. Just call John and ask the mechanism instead of making a lot of assumptions based upon subjective reports. My first assessment, is that John Baloff is an expert on the Casablanca. The mere suggestion by John of any differences introduces a massive "expectation effect." Therefore asking for subjective opinions alone seems useless. i don't discount subjective assessments but I don't discount my education in exp. psych either.

I can't speak for others but my evaluation only switched between the two "modes"; no volume changes between the two. And again any difference was slight and I won't swear it's real; but I can tell you that the volume control was not a part of my A-B comparison.

That was my first question to which was replied:

It is not subjective to ask if a signal is present or not. It is subjective to ask how it sounds. I asked the former.

A few months ago I experimented Matrix vs Stereo modes, two channel, all other speakers and subs "off". I found a 1 dB difference in my setup using Matrix v Stereo, this by ears only. Initially, Matrix sounded better. But once I adjusted the sound level, I really couldn't tell them apart. This was using redbook - don't recall to what extent I used any higher rez material. Volume does make a difference. I recall that I also played using sub crossovers as well as main speakers full range and I couldn't tell any appreciable difference once I subjectively adjusted the volume.

But after reading some of the above, I am wondering if I am "KOOKY"?

Don't have time or inclination to experiment on this further in the near future. Maybe next year?

Steve, have you had the chance to compare the Compli Blu 3D and the Bryston BDP-1?

It hasn't shipped yet. Hopefully within the next few weeks!:D

serial #bruzer001 shipping tomorrow

I now have running right now the first Theta Compli Blu 3D blu ray player, outside of Theta-ATI!!!@@@ Burning in endlessloy playing the blu ray of "Neil Young Journeys", what a fantastic looking and sounding one man concert disc!!@@

I took some photos including with the cover off. Will post them probably tomorrow if I can remember how to post the photos!

A really nice looking and sturdy HDMI transport - looks and sounds great!

Congratulations with the new player.
I'm looking forward to see the pics of the new compli 3D and to hear how good it hopefully is.

Photos of my brand spankin' new Theta Compli Blu 3D!!@@@
Edited by Steve Bruzonsky - 12/8/12 at 2:08pm

Thanks for the pics Steve! I've been pursuing other audio interest and have not been on AVS much lately. It was a pleasant surprise to pop back in and see your pics .

Bulldogger pointed out to me that the picture at the very bottom right, at the very bottom, has my TOES showing up. Some photographer I am!@@

Re the one with your toes, I wonder if the multi-region chip still works on this as it does on the Oppo....it normally fits in the front right of the machine. No multi-region, no interest.

It the chip works on the Oppo 95, on which this is based on, then my bet is it would work with the Compli Blu 3D. Your risk, of course.

So rigid exterior box, better damping for the optical mechanism in the middle, better (linear) power supply on left and the analogue stage ripped out. The digital main board looks basically the same as the Oppo 93/95. No apparent (from the pics) upgrades to the clocks. Hmmm. I have the analogue section in my 93 unplugged (it takes about 2 minutes to do). J H Lee does a linear power supply - as good as Theta? I doubt it. Good enough? Good question. I'd really like to know if Theta did anything to the player-side HDMI etc.

Hi, long time... Congrats to Steve with new player. Would be interesting to get some reports on how it performs compared to the Oppo 93 and also the new 103.