DRPA+ setup

[rec]

Is this a reasonable starting point for my DRPA+ set up for the x-over?
I am reading the DBX forum and this forum. Bare with the noob here as this is my first venture
Into sound setup. Thanks ahead of time

HP filter on the low outputs
35.5hz BW24 0.0db
LP filter on the low outputs
100hz BW24 0.0db

HP filter on the high outputs
100hz BW24 0.0db

I don't quite understand the db setting

Next is setting my limiters & compressor

Here is my equipment list:
2-OT12’s(deltalite 2512, melded array’s) on a QSC GX5 amp
2-T30’s(4012HP, 24” wide) on a QSC 1850HD amp

[BrentEvans]

HP filter on the low outputs
35.5hz BW24 0.0db
LP filter on the low outputs
100hz BW24 0.0db

HP filter on the high outputs
100hz BW24 0.0db

I don't quite understand the db setting

That's dB per octave of gain reduction. Setting it a 0 does nothing. 24 or more is recommended, 48 is preferred.

[rec]

ok, that makes sense
So would I set the db gain for all three areas to 24 as a starting point

[thijs666]

Is this a reasonable starting point for my DRPA+ set up for the x-over?
I am reading the DBX forum and this forum. Bare with the noob here as this is my first venture
Into sound setup. Thanks ahead of time

HP filter on the low outputs
35.5hz BW24 0.0db
LP filter on the low outputs
100hz BW24 0.0db

HP filter on the high outputs
100hz BW24 0.0db

I don't quite understand the db setting

Next is setting my limiters & compressor

Here is my equipment list:
2-OT12’s(deltalite 2512, melded array’s) on a QSC GX5 amp
2-T30’s(4012HP, 24” wide) on a QSC 1850HD amp

Looks very reasonable!

Addition to Brent's post:
To be precise: 'BW24' stands for Butterworth 24dB/octave. 48dB/octave would be better, but not mandatory. If you can, just listen to the differences between 24 and 48 (don't know if your processor has that option).

[raytsmith]

I don't quite understand the db setting

That's dB per octave of gain reduction. Setting it a 0 does nothing. 24 or more is recommended, 48 is preferred.

I may have misunderstood this answer, but I believe it to be incorrect.

Choosing a BW24 gives you the 24 db cut by definition. The db setting off to the side on this screen of a DRPA lets you increase or decrease the signal to balance the volume of your tops/subs.
If your tops run louder than your subs, you can either increase the db setting on the low crossover or decrease the db setting on your high signal to balance them out.

If you raise the db setting to +24, you will run into the limiters pretty quick, and if you haven't set your limiters, you could be shopping for new drivers.

At least this is how mine works - I tried raising the db setting at a low volume, and well before it got to +24 on the Low crossover signal, the T39's completely drowned out my OT12's and the low signal was hitting the limiters.

[rec]

The db setting off to the side on this screen of a DRPA lets you increase or decrease the signal to balance the volume of your tops/subs.

Ok that makes sense. So would I want to start at zero DB and work my way up one I have my limiters set?
Basing my increase or decrease in volume(db) on what I am hearing.
I am not going to run and substantial volume thru my system until I get the limiters set.
I have a volt meter and that is my next task.
I wanted to to get my mind around the xover section first

[raytsmith]

The db setting off to the side on this screen of a DRPA lets you increase or decrease the signal to balance the volume of your tops/subs.

Ok that makes sense. So would I want to start at zero DB and work my way up one I have my limiters set?
Basing my increase or decrease in volume(db) on what I am hearing.
I am not going to run and substantial volume thru my system until I get the limiters set.
I have a volt meter and that is my next task.
I wanted to to get my mind around the xover section first

Mine have been on 0 since the day I got it, except when I played with it earlier today to make sure what I thought I remembered was right....
My understanding is the only reason to mess with it is if you need to balance out the volume of your crossover signals.
I usually balance mine out with the attenuators on the power amps, if needed. Usually, with T39s and OT12s, mine sound pretty close with both signals set the same. Different rooms sound different, and its easier to tweek an amp knob than to change the DRPA screen.

If I were you, I'd leave them on zero until everything else is worked out, then IF you have a mis-match between the volume of your subs and mains, either use the amp attenuators or change the db setting on the crossover screen.

I like the DRPA fairly well, but the manual was apparently not written by anyone who actually uses it. There was a forum off the DBx website with a lot of usefull info on these boxes, dunno if its still around or not.

[rec]

If I were you, I'd leave them on zero until everything else is worked out, then IF you have a mis-match between the volume of your subs and mains, either use the amp attenuators or change the db setting on the crossover screen.

Thanks Ray, that sounds like reasonable advice
I am going to work on setting my limiters tonight
I would agree that the dbx manual is not the best, especially for a noob such as myself

[BrentEvans]

Addition to Brent's post:
To be precise: 'BW24' stands for Butterworth 24dB/octave. 48dB/octave would be better, but not mandatory. If you can, just listen to the differences between 24 and 48 (don't know if your processor has that option).

Choosing a BW24 gives you the 24 db cut by definition. The db setting off to the side on this screen of a DRPA lets you increase or decrease the signal to balance the volume of your tops/subs.
If your tops run louder than your subs, you can either increase the db setting on the low crossover or decrease the db setting on your high signal to balance them out.

If you raise the db setting to +24, you will run into the limiters pretty quick, and if you haven't set your limiters, you could be shopping for new drivers.

At least this is how mine works - I tried raising the db setting at a low volume, and well before it got to +24 on the Low crossover signal, the T39's completely drowned out my OT12's and the low signal was hitting the limiters.

Doh! Never post technical info before lunch. This is the correct info, just different from what I'm used to seeing.

If your unit has a "LR" or Linkwitz-Reilly setting, use that, instead of Butterworth. If you DO use butterworth, you'll have an effective EQ bump at the crossover frequency, which may sound odd, and have to be EQd back down. L-R filters don't have this issue, but do induce a phase shift at certain values, use 48db slopes to avoid this.

[rec]

So I set my limiters last night on the GX5 for my OT12's.
Now I have a couple of questions.

When the OT12's are hooked up and I am playing music thru them I attached my volt meter to the binding post to see what voltage I was pushing.
I was only getting a reading of 1.5 to 2.0 volts.
Is that an accurate reading? It was as loud as I could stand in the spare bedroom at that low of a voltage
I cannot imagine getting up into the 20volt range

Secondly when I set my limiters on the DRPA+ I was selecting the overeasy level (ended up at level 5).
Is that all there is to limiting the voltage? with the speakers disconnected and the amp attenuators turned all the way up, my DJ mixer on 10 and the channel gain turned all the way up I was at 30volts at overeasy level 5.

[Tom Smit]

So I set my limiters last night on the GX5 for my OT12's.
Now I have a couple of questions.
I was only getting a reading of 1.5 to 2.0 volts.
Is that an accurate reading? It was as loud as I could stand in the spare bedroom at that low of a voltage
I cannot imagine getting up into the 20volt range

That sounds about right considering you are in a bedroom! Don't forget, the OT12's are very efficient. Once you get them in a larger room with more sound competition, you will put more voltage to them.

[raytsmith]

Most people here recommend a 'brick wall' type limiter. Since the DRPA limiter isn't a brick wall, the closest you can get is to turn the Overeasy setting off. Or at least turned down to 1. I keep mine on 1, and never hear anything bad from doing so.

Why 1 ? - I dunno - the manual isn't clear on whether it limits harder with the overeasy completely off, or turned on at its lowest setting. I suspect off is the way to go...

If you aren't pushing the volume it might be fine to have it set higher, but if you start getting close to the max, it should be limited harder.

Its better to check voltage using pink noise - music will give a lot of fluctuations and make it hard to tell what you are really putting out.

[rec]

So with the overeasy setting turned to either 1 or off, what adjustment on the DRPA limits the voltage
Sorry if this is a basic quiestion but this stuff is totally new to me
Thanks

[rec]

So after doing some more reading, it looks like the limiter "Threshold" is what limits the signal
Is this correct?

[gdougherty]

Following up on Brent's comment. Highly recommended to use the LR24 crossover type in the PA+. It doesn't have an LR48 option, you have to spend for the DR260 before you get those. An all in one unit like the DRPA+ would autocorrect for any phase issues created by the crossover type but an LR24 type will also be in phase with itself.

Think of the threshold on your limiter as the signal ceiling. When you hook it up to an amp, depending on the size of the amp you'll get a certain voltage output from the amp based on the input signal. When people talk about limiting around here you'd hookup a multi-meter to the output of the amp, put an input signal into the DRPA+ and see what voltage is produced. If the output voltage is too high, then you can roll the threshold down and limit the strength of the signal coming out of the DRPA+ so you never generate too high a voltage out of the amp.