Driverack PA Gain set up - Disabling limiter on amp?

Zonked

Hello all, I hope all is well. I want to set up the gain structure for my system. The instructions say that I have to disable the power amp's limiter. I have an EV CP2200 power amp. I have looked through the manual and it shows no way of manually disabling the limiters. What can I do? Thanks

Martin

Gadget

Nothing... Confucius say man with amp that has no limiter switch end up with limited output... Since there is no way to turn it off... there may be no way to determine if it clips.. perhaps a steady tone.. such as pink noise will fool the limiter.. see what happens...Maybe a no load situation will defeat the \"dynamic Limiter\"... whatever that means.

Gadget

Dra

Why of coarse that means \"to limit the dynamic\". :roll:
I think I'd use the limit lights as clipping indicators. Then possibly put the DRPA just in front or behind that point, depending on if you want more or less.

DRA

Gadget

I'm wondering if the lack of a \"dynamic\" such as a drum hit, or bass peak...screaming vocal...would not trigger the limiter into action...a steady signal such as pink noise while it does have a crest factor..lacks true dynamic peaks...perhaps a call to EV would divulge the needed answers?
G

Zonked

I guess I will have to compromise and as DRA says, I will have to use the limiter lights as the clip indicators for now. I hope that compromise is not to far off from optimum performance. Thanks again.

Dra

It is kind of lose lose. Get into the limiter and lose dynamics. Don't get into the limiter and lose headroom. :?

DRA

Gadget

Well, I know if I engage the limiter on my RMX2450 it goes down from 2400 watts bridged 4 ohms to about 1800...
But what would be the purpose of rating an amp @ 2200 watts @ 2 ohms if you can never achieve it? Another EV brainstorm...
G

Zonked

Lose, lose? So, should just for forget the gainstructure set up? I guess I am up the proverbial creek :? Any other possible sugestions fellas? Thanks.

Gadget

Ahhh...but you miss the point my young padawan...I would guess that the limited power is 2200 watts...see what the gain structure tells you... do you HAVE enough power.. if not you did not choose well...
G :idea:

Dra

Lose may be a bit harsh. How about... whatever you do there is a downside (even if but a little).

DRA

Zonked

So what I will do, is go ahead and try to sep up the system gain structure and see what I get. Now, one more question guys.....The last time I set up my system and fired it up, I found I had to lower the amp to the mains (QSC Plx 1804) to the 9 O Clock position and I had to raise the amp to the subs (EV CP2200) to full up, so I could balance sub to tops. I want to raise the gains for the subs on the DRPA x-over. Now, should I raise the gain on the DRPA before or after I go through gains structure set up? Thanks

Dra

Before we go any farther, what tops and subs are you using. Be sure to give # per cahnnel and if bridging or not?

DRA

Gadget

Actually all this should have been specified in the first thread...\"READ ME FIRST BEFORE POSTING means just that... and in that RMFBP section it specifies that if you DO NOT provide ALL the info of your system you will NOT get any help... there is a very good reason for this...if we don't know for instance what your amps are we cannot decide where your crossover point should be...

Why do you think I chose THAT avatar? I seem to beat my head against the wall and it never seems to change...

That said, this thread has been about a specific amp and it's gain structure setup... now however, it has taken on a \"whole system\" complexity, and even though it seems we need more info I have to say, it still falls into the same category as all the others...Do we just use the \"amp sensitivity method\" or do we mess with the crossover gains to bring the \"amp sensitivity\" voltage into play... your choice, but in the end it really isn't going to matter unless you exceed the headroom of the DRPA... and if you do... there will be HELL to pay...Just ask Dra what happens when you exceed the amps capability...

WARNING.... IF you start messing with the xover gains in the driverack.. make double dog sure you NEVER, EVER, come ANYWHERE NEAR clipping...12 DB of headroom is NOT too much...if you do clip the digital signal...\"Well, pilgram.. that's inviting a passel of trouble\"

IF you can't balance the mains and the subs with the sub amp cranked.. then adding xover gain is a necessity.... adding too much gain can cause digital clipping, and that AIN'T pretty! In fact it is downright DANGEROUS...Want to blow drivers... digital clipping will do it with very little over the clip level... analog distortion is a TOTALLY different subject..It is considered \"warm\" and desirable... Digital clipping is BAD... REALLY BAD... like SERIOUSLY BAD...get it?

Gadget

Zonked

Gadget and DRA, I appreciate your time and you knowlege.

I did read the RBP, FAQ and elswhere, but I didn't see an answer to my initial problem anywhere so I posted. I did not forsee the turn of events, and now it has become the initial problem plus. When I turn the low gain up on the Driverack PA, I will certainly watch for and keep adequate headroom.

Still, don't know if I should raise the gain for the subs before, or after I do a gain structure setup for my system....( tend to think it's after)

Anyway, My setup is as follows:

Tops - Pair of EV ZX4s (400w rms, 8 ohms each)

Amp for tops - QSC PLX1804 (600w/8 ohm, 800w/4 ohm per ch)

Subs - Pair of JBl MRX518s subs (4 ohms each, 500w rms each)
Planning to get an additional pair of MRX518's soon.

Amp for subs - EV CP2200 (500w/8 ohm, 800w/4 ohm, 1100w/2 P/Ch


I guess it boils down to a compatibility issue....I cannot optimize my set up with the EV power amp. What a shame, or a sham.

I will experiment prudently.

If you see anything else with the equipment now listed, let me know.

Once again, thanks for you time and help fellas.

Zonked

Zonked

Ooops! Forgot. No Bridging.

Dra

Try swapping the amps and see if you get a difference.

DRA

Gadget

Your not the only one that has a problem doing gain structure because of something to do with the amp.. The Macrotech line of amps has no clip light at all...but instead a power supply \"health\" indicator (ODEP) ... Again, I suspect that the \"Dynamic limiter\" on the EV amp will still elicit max output with a pink noise (constant) signal...and \"react\" to peaks in a totally different way.

If you do not do the gain adjustment on the DRPA BEFORE you do the gain structure, you will negate the whole process...
Besides, you haven't even tried it yet to find out if there even IS a problem...
G

Zonked

Experimantation is in order fellas. Oh, and Gadget, I did notice your avatar. Being an optimist, at least you are reborn just like the Phoenix

Gadget

Thank you.. that is so apropos... 8)