New install - 2 way help

viper

I removed a dbx crossover, and have started to install the DriveRack PA as recommended to better protect and enhance our system. The DriveRack and amps are installed and wired. I'm using the 2 way quick setup guide. Was doing great until it came time to select speakers and amps. Mine are not listed, and I'm not sure where to go from here.

On the high side we have 2 Peavey SP-6's driven by a Peavey GPS3500.
Connected to the low outputs we have 2 SP218X driven by a CS4080HZ.

The SP6s have 2 15's and mid ~6 inch horn and an RX22 HF horn driver.
The Subs each have a pair of 18 Black Widows.

Reading ahead, the rest of the setup doesn't look too bad if I can first properly define our equipment to the DriveRack.

I just feel if this step is not done right the rest will all be out in left field

Thanks in advance.

Dra

Welcome, Any speaker or amp that is not listed is entered as \"custom\". All that does is tell the DRPA not to \"set\" any pre-loaded parameters, like x-over. Just set up yourDRPA x-over basically how you had you old one. I would recommend using a 24 db slope and LR type between the Hi's and Lows. Set a lo-pass for the subs BW 18 at or just below the -3 db point to give some protection to the subs.
Now you need to do a system gain structure and limiter set as describe in the back of the manual and all over this and the old forum.

***Beware the Auto EQ*** read all you can on this subject before you try to use it. Many pitfalls.

DRA

viper

First, thanks for the fast reply. I'll use the \"custom\" option. Not sure about how to enter the slope and LR yet, but hopefully as I go through the initial config it will become apparent.

The Auto EQ sounds dangerous. Seen many posts. I worry that it will push the horns too hard and damage them again. The main reason we got this was for the limiters, so we don't take out another set of HF diaphragms and bulbs. Peavey has some bulbs that are supposed to dissapate an overload. We found that when the bulbs go, you have to replace them and the diaphragms that they were supposed to protect. Murphy's Law.

Dra

Yes, it is set up in the X-over section after you come out of the Wizard area. If you get stuck post back. It is all cover in the manual.

DRA

viper

Made it through the wizard section. Using the dbx mic, it pinked to a flat response perfectly. Next, setup the Gain structure. at 0 on the board I couldn't get the amps to clip with Pink noise so I justed moved up the slider until they did, then set the High and Low limiter so that they were just short of clipping (and saved). Feel a bit protected now.

The only thing I was not able to do was your recommendation:
\". . using a 24 db slope and LR type between the Hi's and Lows. Set a lo-pass for the subs (4) BW 18s or just below the -3 db point . .\"

This I need a bit of a walk thru (step by step) on.

The system is used for a band, but ran the iPod break music through it, and so far it sounds wonderful. The iPod is also a great place to keep 3min of AAC Pink noise. I prerecorded it to do the RTA, but obviouly didn't need it. (It was used for the gain structure setup).

Dra

1st - the gain structure is to set everything to climp at the same time.
Unplug speakers.
Amp attenuators down.
DRPA x-over gains @ -0-
Board master down.
Select a channel.
Channel fader down.
Channel input gain down.
Input pink noise.
turn up gain until peak / clip light barely ignites.
Bring channel fader to -0-.
Bring up masters to they are clipping (or hitting top red on meter hard).
Turn up amps until they clip.
Go into limiter (not compressor) and set the over easy to 4 (you can play with this, but 4 is common) and set the threashhold to where the amp stops clipping.
Turn the limiter(s) off.
Turn the amps down to where they stop clipping.
Turn limiters on.
Now you have the most protection (although not a brick wall like the 260) you can have AND the most ouput with out clipping the amps.
Now if you alter the x-over gains, redo this proccess.
Also this process should be done after to get the x-over set the way you like it.

I don't have my DRPA in front of me, so take info with a grain of salt.
Press x-over button.
You will see Hi or Lo.
if...
Hi - press select (knob) to scroll through parameters at the bottom of the screen.
Select the freq (hz) and rotate the knob to 100hz.
Press select (knob) and go to filter (may say type) and scroll to select LR24.
The other selection is for gain of that band.

if...
Lo - set the Hi pass (lo cut) where you want it and BW18
Set the Lo-pass (hi cut) to LR24.


You have 2 options to \"balance\" the tops & subs. Never turn up a amp, but you can turn one down. Or use the gains in the x-over to boost or cut(but as always you have to go back and re-do the structure, including limiters).

Back and forth until it's right.


You said you pinked to flat? Remember the the auto EQ is dangerous. read read read

Hope this helped,
DRA

Dra

Oops, forgot to mention that to get from one x-over page( hi, lo/lo, lo-hi) to the next, press \"next page\" button (or previous).

DRA

viper

Wow, thanks for the input. I guess I'll take another run at it tomorrow,
from the begining. I'm learning the unit, and no smoke yet :-)

\"Remember the Auto-EQ is dangerous!\" This bothers me. I haven't found what you're referring to. My guess is that it has a tendancy to force compensation to unsafe limits, but I have not found the link or the aricle yet.

Not sure what good the RTA is if it's that dangerous . . .

Dra

It is wonderful for outdoor use, then you can use the PEQ's to \"mimic\" and then have all the GEQ filtes available for other things. Also to Flatten an imperfect cab (you know those little dips and humps) set up outside and pink away. Then when you have figured out how to use the PEQ and are happy with the response you can save the program and then when indoors you start with a system that is really close to flat and you GEQ adjustmen won't be as severe.

Anyway, have you been to the \"Former Forum\" above? Search \"auto EQ\".
There may even be a \"white paper\" on the subject.

In a nut shell. Only use one stack when doing it. After Auto EQing (inside a venue) look at the graph it gives you. You'll likely see, most of the lower freqs boosted way up. 1) they are boosted because the waves that the mic \"hears\" are canceling at the mic, but not in reality, so the DRPA boosts them to compensate. 2) in this unneeded boost condition there is a real threat of damaging your speakers. The upper freqs are also incorrect for the same but different reason (huh?). Anyway, leave the freqs from 160 to 700 hz where there are (these are not affected by the reflections and cancelations that the room presents to the mic). Return all others (above and below these points) to -0- and then them adjust by ear. Remember that sounds good is good.

DRA

viper

Got in there today and saw what you were talking about in the EQ. Three of the lower bands were pushed @ + 12, and found a bit of that up on the high end. Normaled it out to my \"Ear\", which we've used for the past 18 years :-)

Found the cross over point at set it to 140Hz, as recommended by the manufacture, then changed the slope to LR24. Once you're in there you can see the effects on the graph.

Any other recommendations you have I'd be more than happy to hear or try.

Dra

140hz seems really high for a 15\" (much less a dual 15 cab). That is putting an awful lot of work on the subs and not utilizing the tops. Consider dropping to 120 and take a listen, then drop to 100 , then 90. Then go with what sounds best. If I had to guess I'd say 90 or 100.

DRA

viper

The subs each have twin 18s\" . The SP6s have twin 15's, a 6\" horn and a HF high compression horn. The sub amp is 4000w and the HF amp is around 3500.w 140 was picked to move a bit more into the subs.

I will try varying the xovr just to give a listen . .

Do you recommend any compression of the upper cabs? I was wondering if some amount is a normal/standard to give a precieved boost in level.

Dra

The problem with compression is that if you have dynamics in your music, then you will lose those dynamics. Plus the compressor is whole system, so if your kick causes a reduction, then everything is reduced right along with it. Some DJ's will use compression (set with a really high threashhold) and then boost the gain of the uncompressed signal so that it's all loud, all the time. That a real good way to cook your speakers and overheat your amps, because nothing has a chance to breathe.
My 2 cents....

DRA

viper

I think we'll stick with what we have. We do use compression on the mics set for a very high threshold. (When out in a crowd we've had a few screamers get a hold of the wirelesses.)

Thanks for all your help.

kpippen

Hello Viper,

I agree with Dra... Unless you use compressors only on those individual microphone channels it could cause you more problems than benefit.

System compression allows increased energy to reach amplifiers and loudspeakers,...which may increase the possibility of feedback... When the signal level goes above the threshold,...the level of the signal is then brought down... This makes the overall signal quieter because the peaks have been compressed... Makeup gain (especially in a quite passage) is provided to bring the peaks back up to where they were... If 6dB of compression is used the feedback margin is reduced by 6dB,...and a couple dB more might set the system ringing…

Also,…the increased energy could potentially create failure (usually in underpowered systems) with the loudspeakers (like burn a voice coil),...or it could trigger the thermal protection of an exhausted amplifier from a higher duty cycle (especially if driving a low impedance load),...which will shut it down...

Another side effect of compression might be \"dulling the sound\"… The frequency content of music has a lot more energy in the low frequencies than the high ones... When a kick drum is compressed the cymbal hits (which may happen at the same time) are also compressed…

Now with that being said,...if you do decide to use compression I wouldn't use any make-up gain...

Kevin

PS. Dra,...I stayed at the Holiday Inn last night!...

kpippen

Dra,

Which is it...Ginger or Mary Ann?

The question that has plagued mankind for decades...:)

Kevin

Gadget

Ah the age old question... the pocket rocket.. or the wholesome girl next door...
At my age the pocket rocket of course... :twisted:
G

kpippen

Gadget,

I've always been a fan of good ole sweet home made apple pie...but I'm not knocking the pocket rocket!... Ohhh...you know what I mean...:D

Kevin

Gadget

Well, part of my absence here is that I have a totally cute little pocket rocket right now...and I'm enjoying the dickens out of it!!!! :shock: It's good on a whole nother level... :oops: :idea: I know.. I'll bottle this feeling...! It's like sitting in front of 6 Labs... flat out...blowing away a 6 figure sound system and watching the system provider stew.... Then he realizes all the subs are driven by one 17 lb amp....

Be well guys...I'm heading for the \"barn\"!!!
G

Dra

If I have to pick, it would be Mary Ann. Ginger has too many muscular facial expressions.

Gadget,
Do you have a new motorcycle? Or is that a metaphor? Either way, be sure to wear leathers.

DRA

kpippen

Dra wrote:

Gadget,
Do you have a new motorcycle? Or is that a metaphor? Either way, be sure to wear leathers.

viper

Keep hearing good things about \"Labs\" scattered throughout the forum. the comment about them being driven by 1 amp is amazing. Anyone have a link for more info?

From what I've read it's a DYI project (?) I guess some key questions is what speakers do these beasts have in them, what power is used to drive them? And, are they really that good?

kpippen

Hello Viper,

Here's a start http://www.dbxpro.com/Forum/viewtopic.php?t=611&start=225... The blue text are also links...

You can get all of the information you would ever need at this link http://srforums.prosoundweb.com/index.php/f/3/0/...

Kevin

Dra

Yeah, but what a \"one\" amp.

DRA

kpippen

Yep,...A QSC RMX2450 or BEH EP2500 would have it's hands full trying push \"one\" LabSub...even at 3-ohms in bridge-mono...:)

Dra,...My drivers came in from EM today I'll post back later at the \"Audiophile\" thread...

Gadget

In a word yes.. the Labsubs are awesome.. they are bug, and heavy but MAN do they cook! The amp was a Digam (Powersoft) 5000... now THAT is an amp.. and its the baby of the family...there is a 10,000 series.. :shock: :shock: :shock: YIKES! but the labs are awesome.. they work in groups of two.. but REALLY start to hook up with 6 units ..and with 8 you can pretty much dominate small countries...

Thats great Kev.. PM me some shots of them will you..
G

kpippen

I agree...they are BUG!!!...

Gadget,...see the \"audiophile\" thread...