DBX DriveRack PA2

I was looking for an active crossover and ended up deciding to just go for a full loudspeaker management system!

The goal was - 1.) get full crossover functionality with different filters available, 2.) have remote control capability through PC and 3.) spend no more than ¤400 for it.

The candidates - Behringer DCX2496, Digisynthetic DS24, Phonic i2600, dbx DriveRack PA2 and finally the t.racks DSP's.

After reading ALL the specifications and reviews I could find for each unit, here is a short summary:

Behringer DCX2496: best for pro-level sound systems, where delay lines are a must. Three IN's, two of which can also accept digital AES/EBU signal. Has the most features out of all candidates, but the old remote software and old RS-232 connection are a nightmare to set up (you need an USB modem and not all of them will work). Also, reports of crackling sound and bad ribbon cables inside, along with hum on the signal make it a gamble I was not willing to take.

Digisynthetic DS24: considering the price of only ¤180 (in my country) and having all the crossover filters I needed (up to 48db/oct), it was looking really good! A 3-band PEQ at input and 5-band at output, a limiter, free routing for each output (A, B or SUM) - really all I needed. But then I tried the remote software... it was an epic horror. Buggy, with the graphs for crossover and EQ not working, limiter settings were completely invisible behind a graphics glitch - absolutely useless and out of the question.

Phonic i2600: it is a step down from the DCX2496 in terms of features, lacking in PEQ bands and having one less input channel. Has a USB port for remote control, the software looks good, it even has one digital stereo AES/EBU input. It does two things better than the Behringer - the RTA functionality to automatically measure and set up your sound system and it's got a subharmonic synth for extra bass response. But it's missing ONE important option - the LR 48db/oct filter! It only goes up to 24db/oct, which sometimes isn't enough to roll off a frequency. So I looked at the next option...

The t.racks DSP's: there were 3 models actually, first one the DS 2/4, which had the dreaded RS-232 remote port (not for me), the Achat DSP 24, which looked A LOT like the Digisynthetic DS24 (but 2x more expensive) and finally the DSP 26...which was actually cheaper than DSP 24. That didn't make sense, because it's got 2 more outputs than the former model! Then I read the manual... no LR 48db/oct crossover filters again. Pass!

dbx DriveRack PA2: ...saving the best for last. First off, the negatives - 35% more expensive than the DCX2496. And in terms of professional settings, it doesn't compare to the Behringer (no input/output routing, weaker delay options, no digital ins and one less input channel). But from here on, it starts to catch up - a LAN remote control through a router (even a WiFi one!), snappy modern software, smooth playback while you change settings live (the Behringer actually cuts out playback at some setting changes!). Then, we move on to the full 31-band stereo graphic equalizer, the subharmonic processor, a complete feedback destroyer, the RTA wizard, along with pink noise and white noise generators (all of which don't exist on the DCX2496) and now I saw its price tag as very justified! Then, there is the full filter set on the crossover, 8-band PEQ's on the output stages, a really good limiter and to top it all off - a comprehensive list of presets for different brands of speakers, amplifiers, plus a vivid software that makes setup easy and fun!

My choice was already made on the DBX DriveRack PA2 at this point, but there are 3 more very important things to mention about this unit:

1.) DI Box Functionality - It actually has a +4dbu/-10dbv switch for balanced/unbalanced input signal and a Ground/Lift knob on its back. This means, if you want to connect your PC, phone or home audio to it, go right ahead - no external DI box needed, more cash saved! Eliminates ground hum noise at the touch of a button.

2.) Sound Quality - my ears are happy and so are all other buyers, from the reviews Ive read across the net.

3.) Reliability - again, based on all the reviews, this unit will perform a long time, especially if you take good care of it and don't block its heat vents.

I hope someone finds this review useful! As they say in German, Klare Kaufempfehlung for the DBX DriveRack PA2 from me! Im out :D

This is what makes my speakers play nice at home, and someone else's speakers play nice elsewhere when setting up PA in smallish venues. If you bother learning some of the science behind what this device is for, it'll pay you back in sound quality. The best results are achieved when you have multiple amplifiers and speakers to be driven and spend the extra time to configure the crossover and phase alignment delays before AutoEQing. Also, as usual for dbx rack gear, this one lacks a power switch as well.

This unit has a single stereo/mono input with three stereo outputs of which the LOW output can be configured mono for single subwoofer use. I suggest reading the manual to find out more about the features. (Yes, RTFM before buying!) Some special cases will need a bit more manual tinkering, eg. setting up a PA with three subwoofers. (Yes, one of the setups I did had a full-range stereo pair from HIGH outputs, stereo subwoofers from MID outputs, and a third mono subwoofer in the middle in front of the stage from the LOW output, and it was awesome!)

Originally I was looking for just an analog stereo EQ to overcome some of the acoustic problems at home but started looking at digital speaker management systems instead as the entry level devices weren't that much more expensive and came with a lot of other features which would need a bunch more separate devices in the analog world. The dbx DriveRack® PA2 ended up being my choice with the matching RTA microphone as the cheaper option had (luckily!) just run out of stock. And then it also found use where it's at its best, smaller scale live sound reinforcement.

So far the PA2 (firmware version 1.2.0.1) has locked up only when starting some Wizard features. External app connections will drop when this happens. This eats one of the quality stars, because setting up is one of the times when you want your tools to work. However, it's never done anything stupid after setting up and in production use, so I'll live with the occasional Wizard crash. The Mac software interface follows the layout of the iOS app and is slightly less responsive but does work. The iOS app has proved to be useful to tweak EQ, compressor, and such on the fly while the rack unit itself is somewhere out of reach.

The first A/B comparisons I did with a single stereo output, just with AutoEQ and nothing else, blew my mind with the improvement to the previous EQ-less setup. Later on I tried bi-amping a pair of passive speakers that offered the option. I set up the crossover with the speaker specs and finetuned it by ear, then used the output delay to phase match the tweeters with the full range drivers before AutoEQing. The improved clarity around the crossover range just... I don't have words for it. Let's say it just made an already great pair of speakers sound even better, and there's no going back to a single-amp setup!

The AutoEQ has proved to be great to set the baseline EQ for whatever acoustics the venue happens to have. Sometimes the larger corrections need to be dialed back a little by hand, but that's never been much of a hassle compared to doing the whole EQ setup from scratch. The apps offer you a calculated dynamically updating frequency response result graph when doing AutoEQ fine tunes by hand. The graphic EQ isn't used much by me, but I sometimes use it to make small fine tunes at select troublesome frequencies that resonate in some particular spots of a venue.

Configuring which outputs are enabled can only be done through the Wizard, which takes away half of the handling stars. When setting up special setups you will need to think which wizard choices enable what you need and then set up the crossover manually. I'd prefer a possibility to just enable and configure each output freely instead.

When doing output phase matching, I've used my iPhone and iPad at the same time because the phase inversion button and the alignment delay slider aren't on the same view in the app. This chews another half of a handling star since access to both are often needed at the same time! At the front panel this works fine as switching back and forth between the pre-selected settings happens with separate buttons, but you most likely don't have your PA2 installed in the middle of the venue at the sweet spot where you listen while setting up.

I have also used the PA2's RTA to set up separate EQs, eg. for monitors which are completely separate from the main PA. Just play pink noise through the system you're tuning and use the PA2's analyser to measure the frequency response, just like it used to be done before fancy AutoEQs. This method also works while setting up the crossover to make sure you have an even response around the crossover frequencies. PA2 has a noise generator for this purpose.

The compressor is a nice touch in this thing. So far I haven't needed it to make the PA louder, but I've used it a lot as a soft limiter with 2.4:1 ratio and the OverEasy setting around 4-6, just to keep peak volume in control when playing loud.

The feedback suppressor has been a great trouble solver for what little use I've had for it. The subharmonic synth has been mostly useless for me.

I haven't really used the output side parametric EQs but I've thought of a situation where I'd use the PA2 as a splitter and AutoEQ each output pair separately as needed, then manually transfer the AutoEQ settings to the output PEQs. I haven't used the limiters yet as the amplifiers and active speakers I've used have had them built in, but I'm sure a properly tuned PA2 would do limiting better and more transparently as well.

I had been considering the Behringer DCX2496 Ultradrive Pro, because of the third input, but very glad I chose the DBX PA2 instead.

I had a really weird problem with my sound system... One of the radio mics started to ring slightly so I turned the gain down... and that caused it to howl round completely... so I shut the fader and the howl round continued... so I shut the foldback fader and the howl round continued... so I shut the main output fader and the howl round continued... this is impossible!

I eventually traced it to either the 31 band stereo equaliser or the crossover. I replaced both with a DBX DriveRack PA2 () and DBX DriveRack RTA-M mic to go with it ().

Yesterday a friend helped me take the system with the new DBX digital crossover and equaliser to his warehouse for testing (pictures below). I had been hoping to do some other housekeeping (some new connectors to simplify wiring) with the money in 2017 for the sound system, but the new DBX unit is fantastic. It is quicker and easier to setup!

I used to have use a Phonic PAA () and send pink noise through the system then manually set 64 faders to the correct settings. This was a pain. Pink noise isn't pleasant to hear, especially as there are often many other people in the venue while I'm setting up. The DBX PA2 uses sweep tones and not only is it quick and easy the sound is a lot more pleasant. You can also take readings from multiple places (to correct for acoustics better.

It is also controlled by an app (iOS and Android) and will make my job doing sound for events a whole lot easier. The app walks you through all the settings with wizards (it already knew the Behringer speakers I use so I just selected them from the list, but not the Behringer amplifiers). The wizards are powerful and will help make setup a lot quicker.

One thing I liked was the fact you can make changes on the fly without any glitches, noises etc, so if you want to change eq mid show that's no problem.

Having the system set up in a warehouse away from everyone I could test every setting... and I did! Compressors worked well, as did the limiters: I'm in small venues a lot of the time (200 seats) with occasionally large ones (1,000+) so being able to reset the positions the compressors or limiters cut in will be helpful. The limiters are designed to stop clipping on the amplifiers, and although I use compressors on all the vocal mics (to make the mix more solid) having catch all limiters set on the output will be helpful.

The subharmonic enhancer worked will, producing a warmth to the sound that I liked.

Cons? No third input is the only con I can see so far.