Audax MTM speakers and DBX DriveRack PA

[cpsmith]

Hi all,

I just finished a speaker project designed to get me into the world of active crossovers and tri-amped speakers.

The project is using the Audax 6.5" Aerogel woofers (HM170Z18) and neodymium tweeter (TM025F1) in a MTM configuration. For the active crossover I went with the DBX DriveRack PA over the Behringer DCX2496 for a couple reasons: (1) The DBX has a switch on the back that increases the input sensitivity for use with consumer gear; (2) The DBX has the RTA mic so you can "pink" your room to achieve flat frequency response.

Overall I'm very pleased with the results. When trying it out with my old PSBs, I couldn't really detect any way in which the DBX negatively impacted the sound. Meanwhile the "pinking" cleared up some boomy room response and made the vocals sound more alive.

A couple things to note for others considering the DBX DriveRack PA:
(1) The RTA mic and room pinking requires you to turn the volume up fairly loudly before it runs. This means that it is giving you level frequency response at a loud listening level, which may not sound the same at lower/reasonable levels. As a result I've found myself manually adjusting the crossover a bit afterwards to improve the sound.
(2) The DBX crossover section does allow you to set outputs at reduced dB levels so that it works better with consumer gear. For example, I had all my crossover levels set at -25dB. However the DBX itself produces some static that was audible from my listening chair. What I ended up doing was putting a -28dB voltage divider directly into the XLR connectors (just enough room for the two resistors inside the Neutrik connectors) and then the static was taken away. I then moved my crossover levels back to ~0dB and all was well.

I've put up a more detailed description here for those interested:
Audax Speaker Project

I plan on making some more advanced/expensive designs down the road, but wanted to start out with something relatively straightforward. It's always good to get some practice woodworking before building those multi-thousand dollar speakers, right?

Thanks to the many other members who have posted regarding their experience with these pro-audio active crossovers. It was very helpful!

Cheers,
Chuck

[Studio Au]

I have a broken DCX2496 and spotted a second hand DBX Driverac PA for £250, are you still happy with your choice?

[pinkmouse]

SA, "cpsmith Last Activity: 17th November 2004 05:30 AM".