DBX Driverack PA question

John Chiara

Senior
Jan 11, 2011
931
0
0
Troy, NY
Have a bunch of small systems all using the Behringer DCX 2496. Out helping a friends band tweak his club PA which has a Driverack, and trying to get a basic high freq roll off parametric EQ on the L/R outputs. Is it me or us this unit about as in intuitive as can be?
 

David Karol

Administrator
Staff member
Jan 10, 2011
2,084
22
38
San Francisco, CA
www.davidkarol.com
Re: DBX Driverack PA question

Have a bunch of small systems all using the Behringer DCX 2496. Out helping a friends band tweak his club PA which has a Driverack, and trying to get a basic high freq roll off parametric EQ on the L/R outputs. Is it me or us this unit about as in intuitive as can be?

It's not you- it's the unit.

IIRC, you only have 3 bands of parametric EQ per channel though. Are they actually shelving filters? :)

Have fun!
 

Dick Rees

Curmudgeonly Scandihoovian
Jan 11, 2011
1,551
0
0
St Paul, MN
Re: DBX Driverack PA question

IMO, the DRPA (or PX) is the most mis-used, worthless piece of gear right up there (or down there) with the Sonic Maximizer.
 

Brian jojade

Senior
Jan 15, 2011
718
9
0
Wausau, WI
www.happymacshop.com
Re: DBX Driverack PA question

Or Pain in the Ass. Getting it unchained and all the extra things turned off is hard enough, but then 2 EQ per output in the lows and mids? That's just mean. The 260 is a BIG step up.

I'll have to agree. The PA is a severely crippled piece of crap that shouldn't be out in the wild. The 260, which looks similar on the outside, is a vastly, by a factor of about a million, superior unit. I wouldn't ever waste a dime on anything less.
 

Brent Handy

Sophomore
Aug 22, 2012
194
0
0
Olathe, KS
Re: DBX Driverack PA question

I'll have to agree. The PA is a severely crippled piece of crap that shouldn't be out in the wild. The 260, which looks similar on the outside, is a vastly, by a factor of about a million, superior unit. I wouldn't ever waste a dime on anything less.

I normally sell EV DC Ones over dbx 260s. Recently, I sold a DRPA because it was an emergency. I regret it. The unit is in an amp room that has sequencial power. When the amps are turned off, so is the DRPA. When that happens, a squeal is sent to the audio outputs to the amps. Really sad. The DR stuff is junk because the output processing is not compensated for. Lets say you time align your system and then come back later to add an EQ to the output. Well, your out of time align again. There is no onboard compensation. You have to break out SMAART or something to measure again. Bad deal. I like the QSC processors as well. They offer better features than the 260 and have latency compensated for, no matter what you use or where you use it.
 

Mike Brown

Sophomore
Feb 7, 2012
214
5
18
Re: DBX Driverack PA question

I normally sell EV DC Ones over dbx 260s. Recently, I sold a DRPA because it was an emergency. I regret it. The unit is in an amp room that has sequencial power. When the amps are turned off, so is the DRPA. When that happens, a squeal is sent to the audio outputs to the amps. Really sad. The DR stuff is junk because the output processing is not compensated for. Lets say you time align your system and then come back later to add an EQ to the output. Well, your out of time align again. There is no onboard compensation. You have to break out SMAART or something to measure again. Bad deal. I like the QSC processors as well. They offer better features than the 260 and have latency compensated for, no matter what you use or where you use it.

Since you have experience working with both.... is there any reason to look at the DR260 over the DC-One?

I've used and recommended to clients the DC-One many many times... never even thought to look at the DBX processors to be honest... there doesn't seem to be a reason for the higher price tag.
 

Bennett Prescott

Just This Guy, You Know?
Staff member
Jan 10, 2011
10,848
18
38
36
Wallingford, CT
www.bennettprescott.com
The DR stuff is junk because the output processing is not compensated for. Lets say you time align your system and then come back later to add an EQ to the output. Well, your out of time align again. There is no onboard compensation. You have to break out SMAART or something to measure again.

This is news to me. Are you sure you're not thinking of phase shift introduced by the filters you're adding? I'm not saying its not possible for a processing block to add latency, but I do not recall this being a problem while designing presets using the DriveRack PA. Then again, I always measure while I'm doing my alignments, so a small amount of latency over what I expect from the filters I change could sneak by me and I would compensate for it without realizing.
 

Peter Etheredge

Sophomore
Jan 11, 2011
113
1
0
St. Charles, IL
tnprod.com
Re: DBX Driverack PA question

Since you have experience working with both.... is there any reason to look at the DR260 over the DC-One?

I've used and recommended to clients the DC-One many many times... never even thought to look at the DBX processors to be honest... there doesn't seem to be a reason for the higher price tag.

I've used and installed both. Honestly not a huge fan of the audio quality on the DR260. I don't hate them or anything, and for what you pay they have a nice feature set, but the DC-One just seems to sound a bit better and last I was aware of they can be had for a few bucks less. Plus it uses USB, so no RS-232 adapter headaches.
 

Brent Handy

Sophomore
Aug 22, 2012
194
0
0
Olathe, KS
Re: DBX Driverack PA question

This is news to me. Are you sure you're not thinking of phase shift introduced by the filters you're adding? I'm not saying its not possible for a processing block to add latency, but I do not recall this being a problem while designing presets using the DriveRack PA. Then again, I always measure while I'm doing my alignments, so a small amount of latency over what I expect from the filters I change could sneak by me and I would compensate for it without realizing.

Tis true. Ask dbx. The output DSP is not compensated for.
 

Bennett Prescott

Just This Guy, You Know?
Staff member
Jan 10, 2011
10,848
18
38
36
Wallingford, CT
www.bennettprescott.com
Tis true. Ask dbx. The output DSP is not compensated for.

Do you mean as in "when I enable this PEQ the DSP adds 0.X msec of pure delay, which is not the same as other signal paths", or do you mean "When I add this PEQ the phase is shifted 40 degrees at frequency X and the DSP doesn't add delay to the other signal paths to compensate"?
 

Brent Handy

Sophomore
Aug 22, 2012
194
0
0
Olathe, KS
Re: DBX Driverack PA question

Do you mean as in "when I enable this PEQ the DSP adds 0.X msec of pure delay, which is not the same as other signal paths", or do you mean "When I add this PEQ the phase is shifted 40 degrees at frequency X and the DSP doesn't add delay to the other signal paths to compensate"?

In the DRPA, no matter what you do to channel 1 or 2 on the input side, they will come out in time. All of the processing induced latency has been accounted for. The output processing will add latency, which has not been accounted for. So, if you are measuring all along, it is going to be no big deal. But, if you stop measuring, and go back in to add something, without dialing that back out of the delay on the front side, things will be off a bit. It may not be a big deal for some people and environments, but it is to me.
 

Bennett Prescott

Just This Guy, You Know?
Staff member
Jan 10, 2011
10,848
18
38
36
Wallingford, CT
www.bennettprescott.com
Brent,

You still haven't answered my question directly. I'm not trying to be pedantic, and it sounds like you know what you're talking about, I just want to make sure we're talking about the same thing in order to expand my understanding of this bargain DSP.

Is this pure latency created by enabling additional processing blocks (presumably regardless of whether they are actually used to do any processing?) or phase shift induced latency that is frequency specific and would result from the application of an identical filter in any DSP?

I am being so cautious because there is at least one DSP that inserts pure delay to "compensate" for the phase shift induced by some filters. This has always driven me absolutely batty.
 

Brent Handy

Sophomore
Aug 22, 2012
194
0
0
Olathe, KS
Re: DBX Driverack PA question

Brent,

You still haven't answered my question directly. I'm not trying to be pedantic, and it sounds like you know what you're talking about, I just want to make sure we're talking about the same thing in order to expand my understanding of this bargain DSP.

Is this pure latency created by enabling additional processing blocks (presumably regardless of whether they are actually used to do any processing?) or phase shift induced latency that is frequency specific and would result from the application of an identical filter in any DSP?

I am being so cautious because there is at least one DSP that inserts pure delay to "compensate" for the phase shift induced by some filters. This has always driven me absolutely batty.

Ah-ha. Got it. No, it is not frequency specific. It is latency induced by the process in and of itself, affecting all frequencies of that channel together.
 

Silas Pradetto

Graduate Student
Re: DBX Driverack PA question

It's not you- it's the unit.

IIRC, you only have 3 bands of parametric EQ per channel though. Are they actually shelving filters? :)

Have fun!

There are shelving filters. You can set the highest or lowest filter on each output to be shelving, it's an option on the main EQ screen before you go into each filter.

A huge issue I have with the 240/260/PA/PX line is that they do not actually bypass the crossover filters when you scroll them to 'out'. All it does is change the screen to show that it's off, when the crossover filter is still in, just at the extent of the audible range. While the filter may not affect the magnitude response much, it still causes a MESS to the phase response because the filter cannot be bypassed. So if you intend to bypass the crossover, because maybe you're connecting that particular band to a powered speaker or something, then change the crossover to the lowest order filter present, the 6dB Butterworth.

Yes, I've measured this to confirm.
 

Art Welter

Senior
Jan 11, 2011
833
20
18
Florida
Re: DBX Driverack PA question

There are shelving filters. You can set the highest or lowest filter on each output to be shelving, it's an option on the main EQ screen before you go into each filter.

A huge issue I have with the 240/260/PA/PX line is that they do not actually bypass the crossover filters when you scroll them to 'out'. All it does is change the screen to show that it's off, when the crossover filter is still in, just at the extent of the audible range. While the filter may not affect the magnitude response much, it still causes a MESS to the phase response because the filter cannot be bypassed. So if you intend to bypass the crossover, because maybe you're connecting that particular band to a powered speaker or something, then change the crossover to the lowest order filter present, the 6dB Butterworth.

Yes, I've measured this to confirm.
Silas,

Regardless of the DSP used, the A/D and D/A will introduce latency.
An engaged filter may add to the latency, but to find out how much in any case requires measurement.
Since measurement is needed for precise alignment (to avoid a MESS in the phase response) of a powered speaker using any type of DSP, I don't see that as a huge issue particular to the DBX lineup.

As a user of the DRPA, I have no sonic complaints (other than the shotgun noise when powered down before the amps) though the limited amount of PEQ filters means it is hard to correct truly awful speaker designs, and the limited delay time won't allow super long bass horns to be time aligned.
Polarity reversals on each band would be useful, and it would be nice if the input to output were not polarity reversed, but it is cheap and reliable.

Like any digital device with a tiny interface it is difficult to adjust until you become familiar.
Being familiar with the DRPA and other DBX DSP, I had similar problems John Chiara mentioned in the OP when I first tried adjusting the Behringer DCX 2496.

I would agree with Dick Rees that the DRPA is often misused, but that is commensurate with the knowledge of people generally at the price point of using a DRPA.
Anyone unfamiliar with speaker parameters, time and phase alignment, and measuring equipment will not be capable of good results even with the best available DSP, and generally will make stupid, horrible sounding mistakes.
And then blame the DSP, speakers or amps for their ineptitude.

Art
 

Silas Pradetto

Graduate Student
Re: DBX Driverack PA question

Silas,

Regardless of the DSP used, the A/D and D/A will introduce latency.
An engaged filter may add to the latency, but to find out how much in any case requires measurement.
Since measurement is needed for precise alignment (to avoid a MESS in the phase response) of a powered speaker using any type of DSP, I don't see that as a huge issue particular to the DBX lineup.

As a user of the DRPA, I have no sonic complaints (other than the shotgun noise when powered down before the amps) though the limited amount of PEQ filters means it is hard to correct truly awful speaker designs, and the limited delay time won't allow super long bass horns to be time aligned.
Polarity reversals on each band would be useful, and it would be nice if the input to output were not polarity reversed, but it is cheap and reliable.

Like any digital device with a tiny interface it is difficult to adjust until you become familiar.
Being familiar with the DRPA and other DBX DSP, I had similar problems John Chiara mentioned in the OP when I first tried adjusting the Behringer DCX 2496.

I would agree with Dick Rees that the DRPA is often misused, but that is commensurate with the knowledge of people generally at the price point of using a DRPA.
Anyone unfamiliar with speaker parameters, time and phase alignment, and measuring equipment will not be capable of good results even with the best available DSP, and generally will make stupid, horrible sounding mistakes.
And then blame the DSP, speakers or amps for their ineptitude.

Art

Art, I didn't say anything about latency at all. Simply that the crossover cannot be bypassed even though it says that it is!
 

John Chiara

Senior
Jan 11, 2011
931
0
0
Troy, NY
Re: DBX Driverack PA question

Silas,

Regardless of the DSP used, the A/D and D/A will introduce latency.
An engaged filter may add to the latency, but to find out how much in any case requires measurement.
Since measurement is needed for precise alignment (to avoid a MESS in the phase response) of a powered speaker using any type of DSP, I don't see that as a huge issue particular to the DBX lineup.

As a user of the DRPA, I have no sonic complaints (other than the shotgun noise when powered down before the amps) though the limited amount of PEQ filters means it is hard to correct truly awful speaker designs, and the limited delay time won't allow super long bass horns to be time aligned.
Polarity reversals on each band would be useful, and it would be nice if the input to output were not polarity reversed, but it is cheap and reliable.

Like any digital device with a tiny interface it is difficult to adjust until you become familiar.
Being familiar with the DRPA and other DBX DSP, I had similar problems John Chiara mentioned in the OP when I first tried adjusting the Behringer DCX 2496.

I would agree with Dick Rees that the DRPA is often misused, but that is commensurate with the knowledge of people generally at the price point of using a DRPA.
Anyone unfamiliar with speaker parameters, time and phase alignment, and measuring equipment will not be capable of good results even with the best available DSP, and generally will make stupid, horrible sounding mistakes.
And then blame the DSP, speakers or amps for their ineptitude.

Art

So on the DCX if I want to adjust the left speaker mid section, I press the appropriate output button and then scroll through ALL available parameters for that output. Is the a similar function on the DRPA?