HT Guys...need thoughts on audio

[Mallette]

Just acquired a Roland R-44 4 channel recorder. I wanted to do an "easy" test by loading up my Asylum Street Spankers 4 channel recording from way back. I figured the easiest way to get 4 identical speakers would be to replace the LF/RF speakers I use with my video setup with LS-5s from my office, as I have LS-5s as rears. Now, they aren't ideal for this experiment in that the rears are mounted up on the wall...but I figured it would be close enough.

Plugged LF/RF/LR/RR into the respective analog inputs on the back of my HT receiver and set it to analog multi-channel mode. Seemed straightforward enough, but the rear levels are a good 9db below the front. There are no level settings in this mode for anything except SW out. Even tried reversing the front channels to the rear...still low. Scratching my head... Channels are are 100w and speakers identical. Doesn't make sense to me.

Just thought I'd post and see if I was missing something obvious. Looks like I'll need to try separate amps or something.

I acquired the Roland to get back to my long absence from location recording and I want to work with SoundCube some more

Files still sounded awesome, and I could sense that the rear would be really surrounding if I could just get the bloody levels evened out.

Dave

[Chris A]

Does your HT receiver try to synthesize 5.1 from stereo in its default mode? If so, is there a Pure Audio mode or bypass mode?

My HT receiver provides canned modes and bypass mode(s). This could put the surround channels down 9 dB or more using the front stereo channels and synthesizing LR/RR surround sound channels.

Chris

Edited March 15, 2014 by Chris A

[etc6849]

What AVR are you using? I think some AVR's bypass some processing when you use the multi-channel inputs.

Edited March 15, 2014 by etc6849

[mustang guy]

Just acquired a Roland R-44 4 channel recorder. I wanted to do an "easy" test by loading up my Asylum Street Spankers 4 channel recording from way back. I figured the easiest way to get 4 identical speakers would be to replace the LF/RF speakers I use with my video setup with LS-5s from my office, as I have LS-5s as rears. Now, they aren't ideal for this experiment in that the rears are mounted up on the wall...but I figured it would be close enough.

Plugged LF/RF/LR/RR into the respective analog inputs on the back of my HT receiver and set it to analog multi-channel mode. Seemed straightforward enough, but the rear levels are a good 9db below the front. There are no level settings in this mode for anything except SW out. Even tried reversing the front channels to the rear...still low. Scratching my head... Channels are are 100w and speakers identical. Doesn't make sense to me.

Just thought I'd post and see if I was missing something obvious. Looks like I'll need to try separate amps or something.

I acquired the Roland to get back to my long absence from location recording and I want to work with SoundCube some more

Files still sounded awesome, and I could sense that the rear would be really surrounding if I could just get the bloody levels evened out.

Dave

Are you saying that when you changed the rear speakers to the front and vice-versa, the rear speakers were still 9db lower? If that is the case, 3 things come to mind.

1. There is something about the speaker position where there is less border gain or perhaps some cancellation.

2. There is additional resistance through the rear speaker cables.

3. The speakers are not identical to the fronts. Perhaps something is wrong with them like loose woofers etc.

Edited March 15, 2014 by mustang guy

[Mallette]

The selector says "6 channel analog input." That suggest to me it should be doing nothing but amping and sending to the speakers. Speakers are identical, and while not spaced perfectly not so far off as to have this level of effect. No way wire resistance could be that great, IMHO.

I THINK it's an SX-45 of the Panny Class D designs.

About to watch a movie and see how well it works. I need to move the Fraziers elsewhere when the new owner picks up the Elevens, so I'll likely leave the LS-5s there. The Fraziers were SO much more efficient that even with the rears at +10db they were pretty weak. We'll see if things are a bit more balanced now. About to introduce my son to "Dark City."

Dave

[derrickdj1]

With music, try an extended stereo setting if the avr has one for testing.

[Mallette]

With white noise test, all channels are equal...

Dave

[USNRET]

Less signal (information) to the rears? Does your AVR have All Channel Stereo mode?

[Schu]

With white noise test, all channels are equal...

Dave

Well then... to me this means everything is normal

With content playback, Rears dont normally carry much signal anyway do they? They are mainly for ambiance and movement.

Do you have any 5.1 music to test?

Edited March 15, 2014 by Schu

[derrickdj1]

Schu, that is what I was getting at. The rear speaker usually don't produce the same volume as the front speakers except in an all ch. stereo mode, and only then if they are identical to the front speakers.

[etc6849]

This is still what I suspect. The analog inputs bypass a lot of the digital processing (level attenuation, tone control, etc...) of the unit. Here's a quote from the user manual:

http://service.us.panasonic.com/OPERMANPDF/SAXR45.PDF

"For your reference

¡When DVD 6CH input is on

Speaker settings are ineffective. Change the settings on the DVD player if necessary."

What AVR are you using? I think some AVR's bypass some processing when you use the multi-channel inputs.

[Mallette]

Etc, Derrick, Schu...It's an SA-XR57 and intuitively I assumed precisely the opposite. If it's a true analog through input that is bypassing all HT processing and the channels are all the same power, why would the rear channels be attenuated? As mentioned above, the speaker setting SHOULD be ineffective in this case.

As I mentioned in my post in the two channel forum, I was able to adjust levels on the Roland to attenuate the fronts and achieve a balance. Can't say I am satisfied with that as I still don't see why this is happening. I am also not getting the volume levels I'd like. I was running at -6, almost wide open, which would produce a deafening level with the Fraziers and merely getting loud on the LS-5s, The speakers are much less efficient than Fraziers but 100w PC really should still be more than enough. Further, there was clipping at times which also surprise me given the apparent volume level which I really don't think was much over 90db or so. Guess I should measure it.

In any event, the surround playback was still wonderful and far superior to any of the steering or other surround methods. Of course, that's as an audiophile would expect as simpler is always better and no processing is always better than processing when it comes to fidelity. Of course, the rears being up on the wall and also not precisely aligned with the front (dictated by the room and point where a prior owner had rear speaker mounts on the wall) impacted it a bit but the audience remained firmly where they should be and the ambience was still quite immersive and involving.

Looks like I am going to have to set up a true 4 channel amplifier chain with no HT stuff involved and 4 identical speakers spaced correctly to really do this. Given that's what my research always suggested I guess I shouldn't be too surprised that equipment geared to electronic surround steering can't really handle "pure" correctly.

Dave

[derrickdj1]

Thanks for the clarification. Good luck with the project!