DRPA & Powersoft
fgabor
Posts: 4
Hello,
I'd like to ask for some help, any would be appreciated. The text following seems to be long a bit, sorry about that, but I tried to collect some hopefully useful info.
I have the following setup:
2x JBL Mpro 415 (350W cont, 1400W peak)
DRPA
Powersoft Q4004 (4x1000W/4Ohm, 4x600W/8Ohm)
I will buy 2 pcs of JBL Mpro 418S subs soon, that's why I have the Powersoft Q with 4 channels.
I want to take out the biggest power from my loudspeakers but also prevent them from blowing out.
Here is a link to Powersoft's FAQ site where there can be found some useful information regarding DIGAM amps principles and power maesurement methods (to help you if it is needed:-) and also maybe it can be useful for others):
http://pro-audio.powersoft.it/faq_list. ... u=27&obj=3
And here are my questions:
1. How should I set the gain structure? The problem is, that the Powersoft has its own clip limiter which is about to prevent the amp (and the loudspeakers) from clipping. So it is harder to find the clipping point then at an amp without limiter.
2. Should I use the limiter of the DRPA too (there is no way to set off the clip limiter of the Powersoft) or is it enough to use the Powersoft's one? If it were better to use DRPA's limiter also how should I set it?
3. What is about to prevent my JBLs from blowing out? JBL website says that for live application (this is what we do mainly) the power of the amp should equal the cont. power of the loudspeaker. So what is the reality, I hear many, many different opinions about recommended amp power. And also in my case how is it possible to prevent my speakers? Some information about Powersoft regarding my question's theme: Powersoft has a long-term output power limiting, which acts to reduce the gain of the amplifier in the event of a long persistence (non musical) signal, for example in case of a real sinus wave. So this system works depending on the crest factor of the signal you use.
4. I have an other issue regarding DRPA's negative side, this is the behavior of DRPA during a power failure. This is a serious problem I think, which can have a really bad impact to the image of such a well branded company like dbx (I am marketing manager, that's why I am writing from this point of view also). There are here in the forum a lot of discussions about it, so I only want to know what the dbx guys think about it, and what kind of solution is there to solve this problem, or why do they not try to do something to solve this problem. I think the solution with an UPS can be a solution, but it seems to be not too professional...
I would really appreciate any help from you guys.
Best regards
Gabor
I'd like to ask for some help, any would be appreciated. The text following seems to be long a bit, sorry about that, but I tried to collect some hopefully useful info.
I have the following setup:
2x JBL Mpro 415 (350W cont, 1400W peak)
DRPA
Powersoft Q4004 (4x1000W/4Ohm, 4x600W/8Ohm)
I will buy 2 pcs of JBL Mpro 418S subs soon, that's why I have the Powersoft Q with 4 channels.
I want to take out the biggest power from my loudspeakers but also prevent them from blowing out.
Here is a link to Powersoft's FAQ site where there can be found some useful information regarding DIGAM amps principles and power maesurement methods (to help you if it is needed:-) and also maybe it can be useful for others):
http://pro-audio.powersoft.it/faq_list. ... u=27&obj=3
And here are my questions:
1. How should I set the gain structure? The problem is, that the Powersoft has its own clip limiter which is about to prevent the amp (and the loudspeakers) from clipping. So it is harder to find the clipping point then at an amp without limiter.
2. Should I use the limiter of the DRPA too (there is no way to set off the clip limiter of the Powersoft) or is it enough to use the Powersoft's one? If it were better to use DRPA's limiter also how should I set it?
3. What is about to prevent my JBLs from blowing out? JBL website says that for live application (this is what we do mainly) the power of the amp should equal the cont. power of the loudspeaker. So what is the reality, I hear many, many different opinions about recommended amp power. And also in my case how is it possible to prevent my speakers? Some information about Powersoft regarding my question's theme: Powersoft has a long-term output power limiting, which acts to reduce the gain of the amplifier in the event of a long persistence (non musical) signal, for example in case of a real sinus wave. So this system works depending on the crest factor of the signal you use.
4. I have an other issue regarding DRPA's negative side, this is the behavior of DRPA during a power failure. This is a serious problem I think, which can have a really bad impact to the image of such a well branded company like dbx (I am marketing manager, that's why I am writing from this point of view also). There are here in the forum a lot of discussions about it, so I only want to know what the dbx guys think about it, and what kind of solution is there to solve this problem, or why do they not try to do something to solve this problem. I think the solution with an UPS can be a solution, but it seems to be not too professional...
I would really appreciate any help from you guys.
Best regards
Gabor
0
Comments
We have the Didam series 5000, and the truth is we cant get it to blow up any speaker, no matter how small! We have run 6 Labsubs off the 5000 and it just pounded the living hell out of a square mile of outdoor realestate. %Those amps are amazing..
I wouldn't worry about the limiter in the DRPA. use the powersoft.
As far as power amps go, my take is the bigger the amp the better. Yes, you can over drive the cones, but you stand a far greater risk of damage with too little power. Just make sure your clip limiter lights stay out,or at least onmly hi occasionally.
The turn off thump is a well publisized matter. DBX will not comment on this issue, and will do nothing to change it.. Get the ups and live with it.
Gadget
first of all many thanks for your kind help.
This LabSubs are totally unknown for me regarding power, sensibility and impedance. And also would be interesting how do you use them with the Digam 5000? 3 of them parallel on one side or ...?
But the main thing is that do you recommend me to use my configuration without any fear? Is it enough to let the limiter of Powersoft work and it will ensure the amp not to clipping? So isn't there any chance that my Q4004 will blow my speakers? Of course in the case I keep the way of the signal free from clipping. So does it mean that I have nothing to do beyond this?
And only one more question regarding setting the gain on the Powersoft. When I tried to set it, I found that when I was increasing the gain, the clip LED was starting to blink for a few moments and then became dark when the limiter started to work (as I think). So should I maybe find the point where the clip LED start to blink for a moment and then decrease the gain a bit? By Powersoft this is possible in 2dB steps.
Best regards
Gabor
There was a provider there with 8 JBL 4719's(dual 18\") powered by 4 Crown Mac 5000's and you couldn't even HEAR his system while the labs were on! He was so pissed he could not believe 1, 19 lb 1 rack space amp could blow his system away like that! he actually followed the wires from the amp to the speakers and STILL couldn't believe it!
Just make sure the gain structure is done on the rest of the system properly..
We actually hooked the digam up to a 4 \" speaker and cranked the volume.. it went to a loud volume and wouldn't get any louder.. no matter what we did.. it just wouldn't blow the speaker!
Gadget