Peavey IPR 3000 "DDT" kicks in way before DCX2496 limiter

[ripNdeb]

I set up 4 T39s outside for the first time and with two on each channel (4 Ohms) I had the volumes/attenuators barely over 9:00 before the DDT would kick in and, of course, sound like s$*T. I had previously set my limiters to 50V on my DCX2496. Did I miss something? Is the IPR 3000 too much for 4 T39s?
Thanks,
Dana

P.S. they sounded awesome even though they might have been held back.

[escapemcp]

I had previously set my limiters to 50V on my DCX2496.

With the IPR3000 attenuators fully open? (just checking )

Did I miss something? Is the IPR 3000 too much for 4 T39s?

1490W into 2ohms (published specs)=54.6V (equals 375W per speaker), seems ok (although a little on the close side), or are Peavey telling porkies?
You could measure the voltage when the DDT activates and see what happens then
Also, what is it like with only 3 connected?
This might help troubleshoot the issue... might not, but more info is always good

EDIT: Hang on... 2 per side... not 4 on one channel.. that's not right... it's supposed to do 840W into 4ohms. Measure those voltages and see if that sheds any light on it.

[Ryan A]

I set up 4 T39s outside for the first time and with two on each channel (4 Ohms) I had the volumes/attenuators barely over 9:00 before the DDT would kick in and, of course, sound like s$*T. I had previously set my limiters to 50V on my DCX2496. Did I miss something? Is the IPR 3000 too much for 4 T39s?
Thanks,
Dana

P.S. they sounded awesome even though they might have been held back.

Which is it, sounded awesome or sounded like s$*T? I'll bet its not the amplifier, as the DDT doesn't allow much distortion/clipping.

[Bas Gooiker]

When using LMS i would always remove any amplifier based limiting etc.

[Ryan A]

DDT can't be deactivated. I would recommend checking voltages as well.

[ripNdeb]

It was weird. When the DDT (yellow light) kicked in the bass went away, like a badly compressed swell type of sound. Voltage was checked with attenuators all the way up. I'll recheck everything as I've since added a DEQ2496.

[Grant Bunter]

Dana,
Tell us what you did to set it up...

I only ask because I find what you're saying is a little confusing to me.

Let me see if I'm with you so far:
You set up a signal level, ran it through a DCX to an IPR3000, then used the limiter on the DCX to set a voltage of 50V?
And that was all good, and wasn't making the DDT on the IPR engage?

Now you've added in a DEQ as well and your hitting the DDT on the IPR with the attenuator at 25%, but not hitting clip on the DCX? Which side are you not hitting clip on, input or output or both?

Did you by any chance check the output level buttons on the back of DEQ?
IIRC the output switching at the back of the DEQ can boost output, by about 14dB.
A slight bump while changing leads can switch it.
That may not make the input signal on the DCX clip, but it would bump overall output a lot...

[escapemcp]

And I take it you have the DCX LAST in the chain (so it can still effictively limit). If you have put the DEQ as the last device in the signal chain before the amp then

[ripNdeb]

Yes, DCX tested with 65Hz. At full tilt it was around 76V. DCX was attenuated almost all the way (18 or 24db; can't remember right off the top) to achieve the desired 50V. DEQ was added later but the system wasn't tested after that. It was just run here at home for practice.
At the gig, the DCX wasn't even breathing hard. And, yes, it's last in the chain.
I didn't check the output buttons on the back of the DEQ; truth be told, didn't know there were any
Like I said, I'll recheck everything and get back with the results.
I may be barking up the wrong tree too. Anyone know what DDT sounds like when it kicks in? As there are two more LEDs to go I wouldn't think you'd be able to here is so much as I did. On a related note, anyone know what it sounds like when the DCX limiter kicks in?

[Tom Smit]

Yes, DCX tested with 65Hz. At full tilt it was around 76V. DCX was attenuated almost all the way (18 or 24db; can't remember right off the top) to achieve the desired 50V. DEQ was added later but the system wasn't tested after that. It was just run here at home for practice.
At the gig, the DCX wasn't even breathing hard. And, yes, it's last in the chain.
I didn't check the output buttons on the back of the DEQ; truth be told, didn't know there were any
Like I said, I'll recheck everything and get back with the results.

Did you recheck after installing the DEQ?

On a related note, anyone know what it sounds like when the DCX limiter kicks in?

Awful...if you're hitting it hard.

[sine143]

I assume (sorry if im wrong) that initial tests were done with no speaker load. in the real life situation, you are running a 4 ohm load per side. you sre most likely hot on the same ac supply as when you were limiting, and it might not be up to par (ac voltage supply drops, current drawn skyrockets, amp output is diminished, maybe causing ddt to come on early). coupled with the fact that you are now oushing a 4 ohm load rather than no load, im assuming (sorry again) that the amp just isnt capable of the previously mentioned 76 volts at thst impedence on that power supply.

[MissileCrisis]

My amp does 58 volts no load, limited at 50-55 depending on the sub I'm using I can get the amp to clip with low bass, amp output power at 25hz is not the same as what I limited it at (50 hz sine) , now I could use my other amp but I'm fine with it because I basically have double safety and max volume is more than I need in small rooms.

[miked]

Did you EQ AFTER you set the limter on the DCX? Boosting any freqs, especially bass freqs will raise your output voltage. Sorry if I'm way off here, but it popped into my head and out of my fingers.