Ringing Out The Room – Channel or Overall PEQ?

[AndreasModerator]

Really nice pictures and so misleading. Knowing that the Qu outputs are normalized to +4dBu one could think the +4dB position may be the right one. This is a system where I’d wish to have some more metering… 😉

[[XAP]BobParticipant]

There is a clip light on the speakers, but it’s on the back – possibly useful for the OP, not at all for me

[DoctorGParticipant]

Regarding the volume control settings for the Yamaha speakers: I guess it goes without saying, but the setting of the volume control depends on the level of the incoming signal.

Line-level signals are higher than mic-level signals; the control must be turned down for higher-level signals and up for lower-level signals. The correct setting is one that gives adequate output without distortion caused by over-driving the electronics in the speaker and also leaves some headroom for large signal swings.

It takes a bit of judgement, but the peak/limit indicator is there to help. With the loudest signal source playing, turn the volume control clockwise until the Peak LED flashes, then rotate it counterclockwise a few degrees to give yourself some headroom. How much headroom you need depends on the dynamics of the signal source – that’s where your judgement comes in.

You should recall that this is how most level controls on mixers are adjusted to maximize the signal/noise ratio.

There’s more that could be said, but this should get you going.

[[XAP]BobParticipant]

Yes, but on these, with the QU (a combination I use frequently) I run at the line in level as indicated. That makes good use of the designed output range of the QU.

The limiter light should never light IMHO, but it should be about to do so when the desk hits 0dB (at which point you’ve got much bigger problems)

[DoctorGParticipant]

Yes, the limiter should never light in performance; that is what headroom is for. However, the only way to judge where your signal level is with respect to the limits of the point in the chain where you are working is to get the limit light to flash. As others have said, your actual situation depends on the metering you have at the point where you are setting the level control.

For example, if you have a meter with a string of LEDs that can be used at the point of adjustment, then you can set the gain so that only the yellow flashes occasionally. You don’t have that luxury on the Yamaha speaker.

If your judgement and experience has informed you that setting the level at 9:00 with the QU gives you adequate volume without distortion, then apply that judgement. I was speaking about the more general case.

[Dick ReesParticipant]

Regarding the volume control settings for the Yamaha speakers: I guess it goes without saying, but the setting of the volume control depends on the level of the incoming signal.

Just to clarify a bit, while the gist of the statement is true, the term “volume control” is actually a tad misleading when folks consider that adjusting the control makes the amp “get louder”. Actually, the amp always provides exactly the same amount of signal amplification at all times. It’s a fixed quantity.

What the “volume control” actually does is to regulate the amount of incoming signal voltage required to drive the amp to the full output of which the speaker is capable exactly as stated in bold above. This is absolutely correct.

But it is helpful to school folks about the difference between a control which controls input sensitivity and a “volume knob (sic)”.

In CK’s situation I’d consider beginning with the 9 o’clock “line” setting and confirm with the recommended observation of the clip light and determining the final, “best” setting from careful trial. But in the end, speakers whose peak SPL capability is less than 120dB are not likely to produce either adequate performance volume or quality when tasked with rock/pop. There’s just no useful dynamic headroom and driving them as hard as is likely will have quite a likelihood of distortion compared to a speaker capable of 6-10dB more output…which will simply be twice as loud.

You don’t HAVE to use it, but…

[AndreasModerator]

Don’t want to get too picky here, but

Actually, the amp always provides exactly the same amount of signal amplification at all times.

may be ok for analog power amplifiers but not necessarily for digital amps.
And from a user’s view it doesn’t matter at all, since this only affects the internal gain structure of the box.
The user sees an input, an output (air pressure in this case), a knob to control the overall amplification between input and output and possibly some blinking level indicator.

For this discussion, particularly for the MSRs, it would be interesting where this peak/clip lead is internally connected.

If it is connected at the input of the amp (after the pot, fixed gain afterwards), it probably can not determine clipping from sustained power requirements (i.e. playing bass over that PA). A proper clipping detection should check the output swing regarding to the (internal) power rails, which is much more complicated to realize than a simple “volume” detection.

[DoctorGParticipant]

Once again our great guru DR has spoken. Seems he loves to quibble.

Who said anything about the amp “getting louder?” I think you somehow made that concept up yourself in your effort to prove your vast store of technical wizardry. I spoke simply about signal level control, and that is the description given for the knob in question.

Oh, great guru, please tell me this: If I feed a signal into the speaker in question and rotate the level control about which we speak, what happens to the volume of the sound radiating from said speaker? So does that control regulate the sound volume or not?

[AndreasModerator]

Please not again… Doc, you know the answer to these questions… hopefully… 😉
I do not understand why it is necessary start a new fight after Dick agreed to your previous post and (correctly) described what technically happens inside the box. We’re all free to simply ignore comments containing too much detail or too common information, others may decide to learn from reading, though.

[robbocurryParticipant]

Is this post coming out in paperback or hardback? 😉

[MarkPAmanParticipant]

😀

[audioklaParticipant]

well spoken, Andreas

[AndreasModerator]

Paperback only:

Paperback: 1 Page
Language: all
Contents: table of contents, index, foreword from the author, full length uncut version of original posting
Bonus contents: making of, comments from the author
Size and Weight: 71kBytes

Currently out of stock, sorry… 😉

[DoctorGParticipant]

Andreas, thanks for your humor. Well done.

However, it needs to be directed to DR. He is the one who seems to get his jollies by reading his own views into statements made by others and then taking issue with them. He does it to others besides myself – I’m just one who is outspoken enough to respond to his crazy rebuffs and innuendos.

I regard my remarks to DR as just another form of humor. At least we have added some level of interest to an otherwise dry subject. The kudos need to go to the OP who started this thread. Who would have known that a simple question – Channel or Overall PEQ? – would have generated such wild and wide-ranging verbosity?

Your response regarding an amp always providing the same amount of gain is a good example of how easily one can broaden the context of someone’s statement. I assume you are referring to a VCA, which is one example of an amplifier whose actual gain can be controlled. These things do exist, but that is certainly not the case with regard to the level control on the powered speaker in question. I feel sure that even DR knows about VCAs. I hope he doesn’t take offense.

[AndreasModerator]

I’m not talking about VCAs, I’m talking about ClassD amplifiers which, in fact, follow a pretty different approach in making a lightweight signal strong enough to drive a speaker and produce some air movement. “Amplification” in a ClassD amp is a function of scaling the input signal to some sort of PWM, this could be done easily within the digital domain effectively controlling gain inside the amp.
Just thought it could be worth mentioning for someone interested in details, please ignore my post.

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