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wizard with Peavey gear
mikegrny
Posts: 4
I'm running a Mackie VLZ 1604, driverack PA, PV3800 X1, PV2600 X 2, 4 X SP2X, 4 X SP118. The 3800 handles all four SP2X's at 4 ohm per channel load. I've loaded the SP118's with 4 ohm speakers and run 2 per 2600. I used the wizard to set up. When I got to amp selection I chose the appropriate amps. I adjusted my power amps sensitvity knobs as per the display on the driverack. When I tested the system with pink noise, the amp's DDT lights started flashing before I ran the fader all the way up. I was not clipping on the channels or mains on the board. I thought the wizard settings would maximize my headroom. I was able to eliminate the clipping by lowering the threshold on the limiters to around 5dbs. Should I keep the limiters set like this, or leave it as the wizard set?
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Why would you put 4 ohm drivers in a 118 cab? The 2600... gives.. oh... I see...no 4 ohm bridged rating... hmmm...no 2 ohm stereo rating either...bummer...
That's 900 watts per driver for a speaker that's rated 600/1200/2400 watts...hmmm under powered....
The same problem exists with your tops...650 watts per speaker cab... that's all...to a speaker that wants at LEAST 1000 watts per speaker, and 2000 watt peaks (read that...headroom)
Ok...
you never said WHICH amps were into DDT right away...and I bet you didn't do a gain structure as specified in the READ ME FIRST BEFORE POSTING section...
fact:
1. You are underpowered on BOTH ends...
2. I bet you didn't do a system setup and gain structure? If not then you have no idea, and neither can we, about what the problem really is... not enough info..
My gut tells me you have a few problems over and above the limited power thing... but alas ... you haven't given any where near enough info... We need your processor settings and setup plan for the system...
room size
audience
system function (weddings/DJ/KJ Live sound/etc.)
System DSP...
HPF for the subs
LPF for the subs
HPF for the tops
Please Include crossovers type and slopes for best results...
Are you using the compressors?
Limiters?
if so what settings...
any other modules used? sub synth...PEQ... GEQ.. what adjustments?
Did you auto eq?
So many questions...
Gadget
As far as the gain structure procedure goes, I initially did it before I found the PV amp presets in the wizard. I'm a little confused about the preset idea, Isn't it telling me to set the sensitvity to match the screen? Shouldn't the preset set the limiters for optimum headroom? Or am I supposed to be doing the gain structure procedure and then changing the screen on the preset to match it?
I'm not using any DSP.
This is for live band use with music playback during set breaks.
Running it 2 X 4
Low X Over: BW6 at 35.5 to LR12 at 100 Level = 2.5db
High X Over: LR12 at 100 Level = 0.0
No stereo compressor use on the mains
Hi Limiter-Overeasy 4 / Threshold 16db
Low Limiter-Overeasy 4 / Threshold 18db
No sub-synth, PEQ, or GEQ.
I haven't auto EQed yet. I'm actually just trying to get the gain structure set up in my basement, so I don't have to do this at a gig. Once I brought the threshold down to 1db on the Hi limiter and -2db on the low, I had no amp clipping all the way up the fader. When I say clipping, I mean just an occasional flicker on the DDT. Shouldn't the limiters catch this? The 3800 first and then the 2600's.
The way things are set up they sound great. I played some steely dan (Aja) through them and they were perfectly clear with all instrumentation audible. I'm just concerned with what will happen when I'm pushing them hard outside of my basement.
Not true...all the settings in the DRPA are your DSP..
This is dangerous...the slope is too shallow to protect the woofer and the 35.5hz frequency is too low for your power, and speakers...
The crossover frequency is ok but the slope again isn't steep enough to minimize interaction in the crossover region...
When we use these tools we have to make choices...I must say I don't understand why you chose those crossover types??? her we approach this with a little more pragmatic approach perhaps. We look at the power available, the slopes available and make decisions from a point of knowledge and past experience... a collective experience...
We have found that the LR and BW slopes are very often speced by the manufacturers, but with different slopes than you are using. We have found that a very steep filter is necessary to protect the woofer in the sub... a BW 18 is sufficient but BW 6 is inadequate...
Further, if you intend to overlap crossover regions (as JBL often does) then the BW 24> filters are best for smooth interface.
Adjacent xovers LPF/HPF that do not have sufficient slope and allow too much interaction in the crossover region, which affects the frequencies in the region in a non musical fashion...
We suggest at least an LR24 xover for LPF?HPF from the sub to the tops...
If you decide to put am LPF on the tops THEN an LR 6 is a good choice.
Now, the problem with your scheme here is that with the DDT AND the limiter on the driverack you are limiting the power available, and stacking the limiters like that is giving you a false sense of security.. it shouldn't. too much limiting will INCREASE the potential for damage to the speakers. Limiters are a crutch that gives a false sense of security... your far better off to set the gain structure properly and then you KNOW when the amps are clipping... OR in this case NOT clipping because the board is at clipping and the amps are just below that... your not depending on the limiters to protect you... and if you don't have enough spl then you need more system... not more limiting...
So that said, lets just forget all about the clock setting suggested in the setup wizard... lets use the method in the "START HERE" thread in the READ ME FIRST BEFORE POSTING section ...
viewtopic.php?f=61&t=959
with the DDT OFF on the amps... this will determine EXACTLY where the amps clip, and get all the equipment talking the same language...(voltage) besides, the limiters on the DRPA are not brick wall and the harder you hit them...the more gets through, and the higher the duty cycle of the amp becomes...which will heat the voice coils on the speakers unnecessarily.
After this is done you should really do an auto eq..it will smooth the response of those speakers... and believe me.. they need it if you intend to keep feedback to a minimum...
Oh... and set the HPF @45.5 hz... and yes BW18...this will help with your power issue
G
G