DJ's do you set your limiters with sine waves or music ?

[djtrumptight]

I noticed that when i set my limiters using Sine waves then play recorded music my limiters kick in early and i dont get as much sound from the speakers so what i have been doing for awhile now is setting the limiters with recorded music but i limit my T48's to 53 volts and my DR's to 37 volts.Any other DJ's have that same problem ?

[Grant Bunter]

The only probelm I see with that method is this:
What's to say you played the loudest possible song on your list?
You can only say that if you have analysed every part of every song you have or will play.

The sine wave method guarantees limiters are right.

Reducing your limiter by a volt or two here or there is almost meanningless. Most of the time, in subs, a volt here or there is only a reduction of 10's of watts, not 100W.

If you're into your limiters straight away with recorded music, either your gain structure is a bit out, you're running the system to hard, or you need more cabs.
Part of the "problem" may be that you set the limiter with say 60Hz, but you have a lot of 30Hz content.
Even if you set limiters with a sine wave lower than usual, you will still find yourself into the limiters early.

This holds true for DJ or live music BTW...

[djtrumptight]

I'm not into the limiters straightway.What im saying is,if i set the limiters for my subs with a 60 hz sine wave,when i play recorded music my limiter will kick in at the point i designated but my output coming from my amp will be about 30 or so volts.I remember awhile back another DJ had that same problem,im still looking for the post.

[SoundInMotionDJ]

I noticed that when i set my limiters using Sine waves then play recorded music my limiters kick in early and i dont get as much sound from the speakers so what i have been doing for awhile now is setting the limiters with recorded music but i limit my T48's to 53 volts and my DR's to 37 volts.Any other DJ's have that same problem ?

Using a sine wave will cause the limit to be conservative, by about 3dB over using a "full range" signal. I can't recall where I got that rule of thumb from...there have been a LOT of places I have collected nuggets of wisdom from over the years...and I don't remember all of them.

The advantage of the sine wave is that it is stable. Using music will cause the signal to "bounce"...getting an accurate reading of the amps output voltage would be difficult with a volt meter.

Some slight compression of the music will raise the RMS signal level...and that could be used to get the overall sound level up to par.

[escapemcp]

How are you measuring your volts? Unless you have an oscilloscope (or perhaps a peak volt meter (if they exist??!!)), then you are not measuring the peak voltage... Only RMS. If your voltage is set at, say 50V, them your peak limiter (because that's what it is unless you have one of those fancy amps with RMS limiting as well as peak) will set itself to when the amp outputs 70.7V (NOT 50V!!) due to the 3dB crest factor of a sine wave.

Now if you run music through this system, the RMS voltage on your meter may only measure 35V, but those transients are still at 70.7V when the limiter kicks in. This is down to music's higher crest factor (which I think would be 12dB in this case ).

[escapemcp]

Or maybe that should be 6db as doubling the voltage = quadrupling the power = 2 lots of 3dB. ...

[djtrumptight]

I think i will go back to the sine wave limit,better safe than sorry since i rent my system out alot.I will just limit to the full 60 volts for the T48's and 40 volts for the DR's.Also i remember i set my tops with a 100hz signal instead of 1khz so that could have been a problem too.Thanks for the education fella's.

[escapemcp]

I think i will go back to the sine wave limit,better safe than sorry since i rent my system out alot.I will just limit to the full 60 volts for the T48's and 40 volts for the DR's.Also i remember i set my tops with a 100hz signal instead of 1khz so that could have been a problem too.

Setting the tops with a 100Hz signal though is probably not a good idea. If your crossover point is also at 100Hz (I'm assuming that it is), then the signal is down 3dB at this point (the -3dB thing is the very definition of crossover frequency). 3dB means half the power! So if you set the DRs for 40V @ 100Hz (@8Ω), then that should be 200W (and it is at 100Hz). Once you start increasing the frequency though, twice the power will be able to get to the speakers You probably don't want to allow 400W (56.6V) through to your DRs, and you DEFINITELY don't want to allow someone else (as you are hiring the system out) to allow 400W through (as they won't know/care until they go past the point where the speakers stop making any noise - you would pay more attention when your speakers start sounding distorted and back off accordingly).

Personally I'd be happy setting the limiters on any frequency that is at least an octave away from the crossovers (so 200Hz). With the sub, it's best to pick a frequency that is in the centre (logarithmically) of the HPF and LPF, as you cannot simultaneously get one octave above the HPF (35Hz would mean 70Hz) and one octave below the LPF (100Hz would lead to 50Hz). Around 60Hz is therefore the best bet and will ensure that the crossover slopes are not reducing output when setting the limiter.

Thanks for the education fella's.

Thanks for the thanks for the education fella It was a slow day on the forum anyway, so it was nice to have a question I could answer and get my teeth into. Going over these concepts publicly is good as it helps me remember them. If I have got something wrong someone will correct me, which in turn ensures that I have these things down pat (never did understand that term).

[djtrumptight]

My limiters have been reset using a 60 hz Sine wave for subs and 1khz for tops.You answered questions i had about why we use 60 hz and 1 khz.Thanks again.

[67baja]

(or perhaps a peak volt meter (if they exist??!!))

fyi, my Fluke 87III multimeter does have a MIN/MAX button that can be used as you suggest. Not that it makes it okay to use music to set the limiters, just letting you know that these DO exist. I use it to see what the peak voltage went to my sub when playing a movie scene, etc.

[escapemcp]

(or perhaps a peak volt meter (if they exist??!!))

fyi, my Fluke 87III multimeter does have a MIN/MAX button that can be used as you suggest. Not that it makes it okay to use music to set the limiters, just letting you know that these DO exist. I use it to see what the peak voltage went to my sub when playing a movie scene, etc.

Thanks for that, I wasn't sure if they did make them or not Fluke makes good kit

As a side note, if you did use your multimeter on peak, then I can see no reason why you couldn't use music to set the limiter. Just redline the music and then dial in your limiter so that it hits RMS x root 2 (for a sine, RMS x root 2 = peak) - for a 60V RMS value of the OP, this would be 84.8V. If you are sure that the music is hitting the limiter then setting 84.8V peak means that a sinewave driven through the same limiter & amp settings HAS to result in a 60V RMS figure. You don't need to worry that music isn't constant, as you are only ever measuring the instantaneous peak voltage - there is no time component to average out (which is the very reason why a sinewave is normally used with our RMS (i.e. averaging) only meters).
DISCLAIMER: Please do not use the above (untested) method to set your limiter, follow the plans instead. You could however use the peak function to quickly double-check your settings after using the 'normal' method to actually set the limiter.

[djtrumptight]

(or perhaps a peak volt meter (if they exist??!!))

fyi, my Fluke 87III multimeter does have a MIN/MAX button that can be used as you suggest. Not that it makes it okay to use music to set the limiters, just letting you know that these DO exist. I use it to see what the peak voltage went to my sub when playing a movie scene, etc.

Thanks for that, I wasn't sure if they did make them or not Fluke makes good kit

As a side note, if you did use your multimeter on peak, then I can see no reason why you couldn't use music to set the limiter. Just redline the music and then dial in your limiter so that it hits RMS x root 2 (for a sine, RMS x root 2 = peak) - for a 60V RMS value of the OP, this would be 84.8V. If you are sure that the music is hitting the limiter then setting 84.8V peak means that a sinewave driven through the same limiter & amp settings HAS to result in a 60V RMS figure. You don't need to worry that music isn't constant, as you are only ever measuring the instantaneous peak voltage - there is no time component to average out (which is the very reason why a sinewave is normally used with our RMS (i.e. averaging) only meters).
DISCLAIMER: Please do not use the above (untested) method to set your limiter, follow the plans instead. You could however use the peak function to quickly double-check your settings after using the 'normal' method to actually set the limiter.

No thanks lol,i have reset the limiters with Sine waves and the wife just left,i'm about to fire up the system and see what i get.

[escapemcp]

Trumptight... Any chance you can see what your peak voltage is (without speakers attached)?? I'd be interested to see if it does indeed match up for both a sinewave and music. No bother if you can't measure it, I'm just curious.

[djtrumptight]

I'm just now seeing this.I actually may be able to do this soon,i was searching thru some old post's gathering some information because i plan on taking my system outside to do some tweaking.I will keep you posted.

[Bill Fitzmaurice]

The problem with music is the dynamic range, which can easily run with 6dB peaks above that of the average content. That's twice the voltage. Keeping those peaks in check is one reason for limiting. If you're seeing a lot of peaking that may indicate inadequate compression, which is a different matter entirely than limiting. Broadband compression by 3-4dB will tame those peaks that are causing premature clamping by the limiter.