BillFitzmaurice.info

rec wrote:So after doing some more reading, it looks like the limiter "Threshold" is what limits the signal
Is this correct?

Yep, you need to make sure your DRPA has EQ, sub synth, etc. turned off, and play pink noise through the amp with speakers disconnected to see how much voltage your amp puts out.

Note the voltage on your amp with attenuator settings at -9, -6, -3, 0, etc. If you want to limit your Otops at 30 volts, for example, and -3 on your power amp is 30 volts, set the DRPA limiter threshold to -3.

Thats interesting about the LR slope, I'll check it out on mine. I have the older model, and am thinking the LR settings only went to LR12, whereas the BW choices went to BW24.

raytsmith wrote:

rec wrote:So after doing some more reading, it looks like the limiter "Threshold" is what limits the signal
Is this correct?

Yep, you need to make sure your DRPA has EQ, sub synth, etc. turned off, and play pink noise through the amp with speakers disconnected to see how much voltage your amp puts out.

Note the voltage on your amp with attenuator settings at -9, -6, -3, 0, etc. If you want to limit your Otops at 30 volts, for example, and -3 on your power amp is 30 volts, set the DRPA limiter threshold to -3.

Thats interesting about the LR slope, I'll check it out on mine. I have the older model, and am thinking the LR settings only went to LR12, whereas the BW choices went to BW24.

Believe they all went down to LR24. Worth the switch. It allows you to develop EQ's for just the components of the system that get each portion flat down past the crossover frequency then combine them together and just adjust relative gain with no additional headaches. With butterworth your crossover point is at the -3db point on the slope, so in theory you could calculate the -6db points on each side and adjust your frequencies out to there. You've still got phase issues though, so you might as well just use the LR slopes.

I have the following turned off EQ, sub synth, etc.

I have followed the advice on setting my Gain Structure. That went ok and is pretty straight forward.
http://www.dbxpro.com/forum/viewtopic.php?f=61&t=959

My questions arise when setting my limiters. I can play pink noise and turn my amps up to where they just clip. As soon as I turn the limiter to ON my voltages drop considerably. The voltage is nowhere close to what everyone recommends, even for half power. Then if I decrease the threshold the voltage drops even more. Is this what is to be expected, or am I missing something basic?

rec wrote:I have the following turned off EQ, sub synth, etc.

As soon as I turn the limiter to ON my voltages drop considerably. The voltage is nowhere close to what everyone recommends, even for half power. Then if I decrease the threshold the voltage drops even more. Is this what is to be expected, or am I missing something basic?

Never noticed a drop by just turning the limiter ON on mine, until the theshold is lowered, then it will drop the voltage. You might try turning the Overeasy completely off, or turn it on to the highest setting and try that, and make sure your db settings are at 0.

Its been a while, but I do seem to remember mine being a bit squirrely that way. I ended up bypassing the DRPA, running pink noise straight from the mixer to the amp, and getting the voltage measurements there, then hooked the DRPA back up and set the threshold according to the numbers I wrote down. I haven't broke anything yet, and have cranked it pretty hard on several occasions.

I'm sure there are other ways of doing it....maybe someone else has a better understanding of the process.

rec wrote:I have the following turned off EQ, sub synth, etc.

I have followed the advice on setting my Gain Structure. That went ok and is pretty straight forward.
http://www.dbxpro.com/forum/viewtopic.php?f=61&t=959

My questions arise when setting my limiters. I can play pink noise and turn my amps up to where they just clip. As soon as I turn the limiter to ON my voltages drop considerably. The voltage is nowhere close to what everyone recommends, even for half power. Then if I decrease the threshold the voltage drops even more. Is this what is to be expected, or am I missing something basic?

What's the threshold setting when you initially turned the limiter on? As you decrease the threshold, I'd expect the voltage to decrease, yes. Higher signal into the amp = higher voltages. Lower threshold on the limiter = lower signal to the amp assuming the input signal to the DRPA+ is above the threshold.

I decided to resurrect an old thread instead of making a new one for my question.

To do an accurate RTA is it necessary to use the dbx's mic or can I use a 58 or an E835?

Dan30 wrote:I decided to resurrect an old thread instead of making a new one for my question.

To do an accurate RTA is it necessary to use the dbx's mic or can I use a 58 or an E835?

You need a flat mic.....vocals mics like a 58 don't cut it. You'll need a reference mic. There are several out there.

Thanks for the help Bruce. With some searching I found a website with side by side charts of different reference mics.

http://www.realtraps.com/art_microphones.htm