Setting limiters - Which mutlimeter?

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Noclu
Posts: 22
Joined: Sun Nov 20, 2016 11:03 am

Setting limiters - Which mutlimeter?

#1 Post by Noclu »

Hello everybody,

i worked thru the Setting limiter thread, and read what Bill wrote to the T60´s on the plans.
We run 2 T60 (15") on one Proline 3000 Channel in parrallel.

I took my cheapo multimeter and measured 50V (tested different frequencies from 50 - 200 without filtering - Had no chassis connected, just the multimeter)

After realizing my DCX2496 (probably) cant limit the Proline 3000 accordingly i built a small PAD Adapter to reduce the incoming Signal on the AMP.

Now i sent maximum Signal thru the DCX, measured around 50V on my multimeter and set the limiter that it won´t exceed 50V.

My question now is (as i´m no electronics expert, and not too good in english) Do i need to make the measurements with a true RMS multimeter?

I mean, the two T60´s are loud, but i got the feeling that i did something wrong.

As the AMP is rated 1300W at 4 Ohm. Without limiting i measured up to 130V (without PAD adapter) per channel with my multimeter.


Please correct me if i´m wrong, as i´m kinda new to the limiting stuff.
Blew 4 PD 1550 in our old scoops before and trying not to blow the two T60s

Thank you

Kind regards

Noclu
Last edited by Noclu on Sun Jan 08, 2017 3:56 pm, edited 1 time in total.

Bruce Weldy
Posts: 8301
Joined: Fri Nov 27, 2009 11:37 am
Location: New Braunfels, TX

Re: Setting limiters - Which mutlimeter?

#2 Post by Bruce Weldy »

Noclu wrote: As the AMP is rated 1300W at 4 Ohm. Without limiting i measured up to 130V (without PAD adapter) per channel with my multimeter.
1300 watts at 4 ohms is 72 volts. Are you sure you didn't have the amplifier in bridge mode?

130 volts would produce over 4000 watts at 4 ohms.

What amp are you using?

6 - T39 3012LF
4 - OT12 2512
1 - T24
1 - SLA Pro
2 - XF210


"A system with a few knobs set up by someone who knows what they are doing is always better than one with a lot of knobs set up by someone who doesn't."

Noclu
Posts: 22
Joined: Sun Nov 20, 2016 11:03 am

Re: Setting limiters - Which mutlimeter?

#3 Post by Noclu »

Oh, you´re totally right!

We use the T-Amp Proline 3000.

The amp shouldn´t be in Bridged mode, but accordingly my measures it must´ve been or my multimeter or the amp is defective!

I will take new measurements made sure the amp is not in bridged mode!

Edit :

But to get back to the multimeter - i checked the description - no info about true RMS or something in it. So i think it´s a Peak/Peak one?

What should i use as guideline for limiter setting?

Grant Bunter
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Location: Ilfracombe Queensland Australia
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Re: Setting limiters - Which mutlimeter?

#4 Post by Grant Bunter »

You don't need True RMS.

You are looking to measure AC volts. It seems what you have already is doing the job...
Built:
DR 250: x 2 melded array, 2x CD horn, March 2012 plans.
T39's: 4 x 20" KL3010LF , 2 x 28" 3012LF.
WH8: x 6 with melded array wired series/parallel.
Bunter's Audio and Lighting "like"s would be most appreciated...

Noclu
Posts: 22
Joined: Sun Nov 20, 2016 11:03 am

Re: Setting limiters - Which mutlimeter?

#5 Post by Noclu »

Thank you!! :)

CoronaOperator
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Joined: Wed Mar 25, 2009 7:07 pm
Location: Medicine Hat, Alberta, Canada

Re: Setting limiters - Which mutlimeter?

#6 Post by CoronaOperator »

Noclu wrote: But to get back to the multimeter - i checked the description - no info about true RMS or something in it. So i think it´s a Peak/Peak one?
The cheapo multimeters display a "calculated RMS" voltage which is the same as "true RMS" when measuring sine waves, up to about 3500 hz. Above 3500 hz they can be a few % points off. "True RMS" meters are only useful when the waveform is very irregular, has spikes,non-sinusoidal waves, etc.
Built:
17" width 10" driver Autotuba
2 x 29" width dual Lab12 Tuba60
6 x DR250 2510/asd1001
In progress:
2 x DR250 2510/asd1001
For best results, point the loud end of the array towards the audience

Noclu
Posts: 22
Joined: Sun Nov 20, 2016 11:03 am

Re: Setting limiters - Which mutlimeter?

#7 Post by Noclu »

Thank you, too! :)

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