How to balance channel level in RSP1068

[wywong]

Hi, I wonder if anyone out there can answer the following questions:
- the result using the Sound and Vision disc is different than the Rotel 1068 sound test. For 75 DB, the sound and vision test need the left front speaker should be at +6 db, center - +8 db, right front - +7 db, where as using the Rotel 1068 pink noice, left front - +7 db, center - +5db, right front - +7db. Who should I trust. With different settings, the sounds are different.
- when I use the SPL, should I point the SPL toward the speaker directly or should I point the SLP to the ceiling. Which way will produce accurate results. I found out that position the SPL meter yield different result. Thanks!!

[Cracking Oboe]

Hi WY.

The 1068's tone generator is poor. I would trust the Sound and Vision disc. You could also try the "THX optimiser" included with many DVD titles (like Monsters Inc.) and see what readings you get with that.

Point the sound meter to the ceiling at ear level to take your readings. (set to "C" weighting and slow)

Looking at your adjustments so far, it appears that you are working your Pre/Pro pretty hard. I'd suggest lowering your F/C/L levels to zero, and set your surrounds to -6 (or whatever result you get). Let the amp work harder as it is designed to.

Cracking!

[alkalay]

Hi Cracking,

What do you mean by "working your Pre/Pro pretty hard"?

Is it really so? Does lowering the channels levels put less stress on a pre? It's not like we're talking about any kind of amplification as far as the pre "cares", are we?

Itai.

[Cracking Oboe]

Should your Pre/Pro's speaker levels be at Max + /Min - / or 0?

Hi Cracking,

What do you mean by "working your Pre/Pro pretty hard"?

Is it really so? Does lowering the channels levels put less stress on a pre? It's not like we're talking about any kind of amplification as far as the pre "cares", are we?

Itai.

Akalay

Well, now that you ask, I think that is a good question to ask me. (I'd hate to spread untruths).
I thought I read it here in HT guide- Club Rotel - but I can't find the thread - the source seemed trustworthy. In previous years, I had seen several receivers, which would not allow you to increase the speaker levels - only lower them. As a result, the thread seemed reasonable to me. I turned my 1068's settings down as I had suggested to WY. IMHO it ran cooler afterward. (A false illusion proceeded from the heat-oppressed mind?)

Perhaps the electrical engineers on the site could confirm what I had been led to believe:

What is the optimal range to set your speaker levels at? (Assuming 5 identical, evenly spaced speakers should the speaker levels on a Rotel all be set to +7, -7, or 0 ?) Why?
Do processors operate differently than analogue two-channel preamps (which I thought acted simply as attenuation devices) and do pre/pro's handle the signal differently post processing requiring increased demands from the power supply?

Cracking!

[wywong]

Hi, this would be an interesting question. We could either crack up the volume to achieve the 75 db and then adjust the channel level, or we could increase the channel level and leave the volume to a normal listen level. I never thought it would make a different and will work the pre/pro harder. This is an interesting question, and I wonder any expert out there can answer. I am using the Rotel RSP 1068 with RMB 1075 amp.

[alkalay]

Let it Continue...

I don't see how does an example of a pre letting you only lower the levels support the stress issue. It may be just an implementation matter.
How 'bout if I told ya the 1068 only let ya lower the settings as well. Take the highest level as +10 and anything below is lower than that.
Am I missing something? Does it matter if the display goes from -10 to +10 or -20 to 0? What are those -+ db are related to? The original signal? Are they? Do all pre at 0 level send an exact signal? If they don't it really doesn't matter what range of numbers is displayed.
Am I missing something here?

Itai.

[Kevin D]

The pre-amp is adjusting the low-level signal. Depending on how good the amplification is in the preamp, it could be good or bad. If it's not the greatest amplification, running close to max levels on the adjustment could add distortion and noise to the signal. If the amplification section is good running things close to max could give you a stronger signal going to the amps letting them run more efficient and not as hard.

Chances are it probably won't sound any different either way on the 1068.. I typically turn the main unit up to '75' and then set all channels to 75db. If it's +8 or -8 across the board so be it..

Kevin D.

[Cracking Oboe]

I don't see how does an example of a pre letting you only lower the levels support the stress issue. It may be just an implementation matter.
Itai.

alkalay,

On it's own... it meant nothing to me (IMHO it was just poor implementation). One would have to be pretty thick to make such a far reaching conclusion about setting channel levels from just that. It was only after I read the thread suggesting the middle range levels (maybe at a different site?) that it reminded me of these other units and think, "hmmm...".

Kevin,

Am I understanding you correctly? Is there a degree of amplification of the signal in an A/V preamp that could be stressed in some poor quality pre/pros if the output settings are set high? But, not in quality equipment like Rotel? Thanks for your input.


Cracking!

[Kevin D]

Kevin,

Am I understanding you correctly? Is there a degree of amplification of the signal in an A/V preamp that could be stressed in some poor quality pre/pros if the output settings are set high? But, not in quality equipment like Rotel? Thanks for your input.

Cracking!

Sure, in theory.. You going to get a certain level signal from the source. To go higher will require increasing the output. Again, it probably won't have any effect at all on the sound untill you get to full reference levels..

Kevin D.

[wywong]

Hi,
Thanks for all your reply. I do not know the technical reason, but when I turn the RSP1068 speaker channel levels down to 0, crack up the volume to achieve the 70db sound level and adjust the speaker level one by one. I got left front 0db, center 0db, right front +1db. Guess what the sound is a lot more smoother than my previous settings of +7db, +8db and +7 db respectively, especially with the vocal and the high. I also got more solid bass (i guess the RMB1075 is working harder now because when the new settings, the volume has to be crack up to at least 8-10 db more). Thank you Cracking Oboe, you really help me to fine tune my system a step higher.

[basementjack]

I would say you'd want the levels at or close to zero, if only so that you could use the remote's C, R, and S buttons for on the fly adjustments, which start off at whatever level you had set.