How to properly setup the DBX DriveRack 260 speaker processor

Hi Jonathan,

As you've requested, I've started a thread so others can benefit from this. I have the Monolith IIIx speakers and will be using the 260 as an active crossover and for all the other neat things it can do. At first, I'd like to try it as a 2 way with the 12" woofer. I also have a pair of 15" open baffle subs, and I'll eventually work my way up to a 3 way system. Thanks for your help.

Adrian

Hi Adrian, cool, we'll cover all the bases in this thread.

First off, we'll discuss the process of setting up for a 2-way. But before we start, you need to have the DriveWare program installed on a laptop or PC so you can connect to the 260 via the serial cable they come with.

If your laptop does not have a serial port, you can use USB to serial adapters such as this one.

Once your laptop is connected the Driverack, we can load an existing config I'll upload in a separate post that will get you started.

Oh, this is so cool. I don't think my laptop has a serial port, but I may already have an adapter somewhere at home. I'll be back in touch after I get the software loaded. Should I go ahead and order the DBX mike, or can I use the Peavey unidirectional mike I already have?

Adrian

Since we really will not be using the DBX itself to do the measurements, it probably does not matter, as long as there is a reasonable match calibration file available for that Peavy mic.

You will be using an acoustic measurement tool such as REW to check the results and tune based on in-room responses.

OK, I wondered whether to extract a ton of info I have on Drive Rack setup from a word doc and do a long sequence of posts, or just post a PDF. I'm busy, so here's the PDF for now. If everyone wants to see this as a big old string of posts, I'll consider breaking it out.

It's not yet complete, as the whole discussion of gain management is not in there yet. I have drafts of that that I'll post this weekend.

See the PDF here.

Oh, is this software or hardware that I need to buy? Can you send me a link, or am I jumping ahead of things?

I did manage to find a couple of serial to usb adapters last night. I downloaded the proper driver for the one I chose, and it installed just fine. However, it wanted to use COM4 while the manual states that the 260 looks for COM1. Even after I got the adapter changed over to port 1, the DriveRack hangs when I try to open it. The laptop doesnt see it yet. I'm running XP home edition. All the pc installation requirements are being met. What now?

Adrian

Here are the actual DriveRack Config files I have:

The first is one I created for another forum member who had a sub in his config:
(Remember to right mouse-click and select 'Save Link as...')

Monolith Active - Contains a 2 x 5 setup with two variations.

Here is the Guide Doc to the configs included.

These others are ones that I had lying around and are undocumented:

DR260-rears 2x4 is a 2x4 config (might match best where you are starting from)

DR260- Rears - I don't recall what this one was

DR260Monolith - Is a config I had used on the Monoliths for a while.

DR260 Monolith 2x5 - is an early draft of the of the documented one above.

Just load these in DriveWare and you can see what they have.

jedi35 said:

Oh, is this software or hardware that I need to buy? Can you send me a link, or am I jumping ahead of things?

I did manage to find a couple of serial to usb adapters last night. I downloaded the proper driver for the one I chose, and it installed just fine. However, it wanted to use COM4 while the manual states that the 260 looks for COM1. Even after I got the adapter changed over to port 1, the DriveRack hangs when I try to open it. The laptop doesnt see it yet. I'm running XP home edition. All the pc installation requirements are being met. What now?

Adrian

Click to expand...

The REW software I link in that doc is free. But you might need to get an audio interface (~$80) (which they discuss at length on their forum) to interface the mic to the laptop and the laptop to your audio system for the measurements.

DriveWare works with other Comm Port IDs, I used to use Com4 on a multiport serial card in my automation PC for it. So I know that's not it.

Check the Comm port setting in the app, ensure it's set for whatever you adapter is set. Then quit the app, then reload.
IIRC, the app does not dynamically switch comm ports and you need to restart the app after switching Comm settings.

Let's talk about physical setup.

Do you have an all balanced chain (using XLR's) between preamp, driverack and amps?

If not, what is it?

Yep, I've checked the port settings in device manager as well as in the Driveware software. Both are set for the same COM port. I've tried port 1 as well as 4. I'll try some others when I get home tonight. Thanks for the ideas.

Ok, I have unbalanced outputs only coming out of my tube hybrid preamp. Right now, I do have XLRs and RCAs on the 2 stereo amps for the Monolith panels and woofers. One unbalanced stereo amp powers the 2 subs that I'd like to add to the system later, after I learn my way better. I'd just been using an adapter to go into the previous crossovers, XLRs out to the Monolith amps, and XLR to 1/4 " cables for the sub amp, since the RCAs on that amp are dedicated to the surrounded receiver front channel, when in use. The Monolith amps are the same, but the sub amp is something else.

Adrian

jedi35 said:

Yep, I've checked the port settings in device manager as well as in the Driveware software. Both are set for the same COM port. I've tried port 1 as well as 4. I'll try some others when I get home tonight. Thanks for the ideas.

Click to expand...

Remember to quit the app after making a com port setting change and re-launch.

jedi35 said:

Ok, I have unbalanced outputs only coming out of my tube hybrid preamp. Right now, I do have XLRs and RCAs on the 2 stereo amps for the Monolith panels and woofers. One unbalanced stereo amp powers the 2 subs that I'd like to add to the system later, after I learn my way better. I'd just been using an adapter to go into the previous crossovers, XLRs out to the Monolith amps, and XLR to 1/4 " cables for the sub amp, since the RCAs on that amp are dedicated to the surrounded receiver front channel, when in use. The Monolith amps are the same, but the sub amp is something else.

Adrian

Click to expand...

The first item of business might be to put in an isolation transformer between that preamp and the drive rack.
This will eliminate any risk of hum becoming an issue.

As I mention in the setup guide, a Jensen is unbeatable. let me know if you need one (or two), as I have 2 available for sale.

But if your current adapter cables work (without hum), then fine for now, but I highly recommend the Jensens.

OK, sounds like the cabling to the rest of the rig is handled then. So we wont go into that.

Gain structure between all this stuff will need to be addressed, but we'll get into that as we go.

Adrian, what is the nominal VRMS output spec for your pre-amp?
(it should around 315 VRMS)

What is the max output spec?

Or point me to the manufactures spec sheet.

This has to do with figuring gain management into the driverack.

BTW- this is why I am a huge advocate of digital everything, as analog impedance/level interfacing is a PITA. But then so is figuring clock synchs and all the myriad data formats on digital. Sigh, one can't win, it will always be complex.

It semes that I'm in good shape as far as hum (or the lack of it) is concerned. The tech who built my adaptor used to repair Threshold amps, and he's quite knowledgeable about these kinds of things. He built something of very high quality and was very concerned about how the pins were connected, cable quality, shielding, etc. There is currently no noise in the system, even after running through 2 McLelland pro xovers that don't seem to be as high quality as the 260. I'd like to start off by using what I have. If I get into trouble down the road, I'll go with the Jensens. I hope that sounds ok to you.

My preamp is the Audible Illusions Modulus 3A. I still have the paperwork somewhere around here, so I'll have an answer for the spec you need soon.

The Monolith amps were built by another local tech who has a company called BPT(Balanced Power Technologies). He personally uses his own digital amps that run on his own battery power supplies. He's selling me 2 analog balanced amps that use the ICE amp power modules, ordered directly from that company or website. I'll have to find out more about the specs, but they should be standard for what a 250 wpc(into 8 ohms) ICE amp should do. Yes, I know those use a switching power supply. They sound good for now, and don't have to do any low bass. My Threshold Model 4000 amp is having the right channel rebuilt by this same guy. He found that the amp was unstable and subject to blow at the drop of a hat because whoever had been fixing it in the past had been using cheaper output transistors that are not as rubust as the originals, not the same size, and certainly not the same specs. This created variances, overloads, and shorts. He also said that it creates a huge amount of noise. A section of the main circuit board go burned, and needs to be dealt with. It'll cost me, but it sounds like he can fix it correctly so that I can use it long term as my ESL panel amp.

Eventually, I'll have my two Krell KMA 100 monoblocks back. I need to pay off a loan from last summer to get them. A friend is keeping them safe. They'll probably drive the Monolith woofers, or maybe the 15" subs when I'm ready. Right now, I'm using a simple Parasound stereo amp(HCA 800 MKII) for the subs. It does 100 wpc into 8 ohms.

Yes, I have been closing out the Driveware program when the com changes were made. Heck, I even tried restarting the laptop. Nothing has workd yet. There has to be an answer to this.

Wow, it sounds like there is a lot of stuff that I still need to buy just to get started with the measuring setup. Along with the Jensens, do you have any extras fo sell? Could you explain why we will not be using the 260 to measure things?

Regards,
Adrian

My preamp has a high level section and a phono section. Specs in the manual for the high level section include gain, THD, signal to noise, overload, input impedance, signal phase, freq. response, slew rate, overall gain, output impedances, and tube compliment. I can do some checking on the web if none of these are what you need.

Edit: Here is a link to a indepth review that mentions a lot of specs for my unit:

http://www.stereophile.com/tubepreamps/316/

Adrian

Here is a link to the specs on the manufacturer's website:

http://www.audibleillusions.com/products/M3A_specs.htm

jedi35 said:

...
Wow, it sounds like there is a lot of stuff that I still need to buy just to get started with the measuring setup. Along with the Jensens, do you have any extras fo sell? Could you explain why we will not be using the 260 to measure things?

Regards,
Adrian

Click to expand...

Actually, very little more required to do measurements, you already have the mic, the software is free (REW) and all you need is an audio interface.

If the mic is a phantom powered XLR-connected mic like most, then you will need a gizmo like this one to connect it to the laptop.

Tascam US-122mkII




As to why you can't use the DBX for measurements, well, all it does is Real time analysis on the front panel, no way to actually see and graph what is measured except for the bouncing bars. Not very accurate for what we want to do.


A good audio measurement rig is to an audiophile what a good tape measure is to a carpenter. Can't do a good job without it

Once you get that Tascam, you perform a soundcard calibration, a loopback is connected from a right channel line-out to a right channel line-in and then removed once the calibration file is created and saved.

For actual measurements it's pretty simple. One cable to the mic, and one cable to the preamp. That's it.

Here is a diagram of how you use it with REW:

jedi35 said:

Here is a link to the specs on the manufacturer's website:

http://www.audibleillusions.com/products/M3A_specs.htm

Click to expand...

Ok, it looks like it probably has enough juice to get a decent gain structure. The max distortion claim is at 1.5v output, which should only require increasing the input gain in the DBX by +3dB or +4dB.

jedi35 said:

..

I did manage to find a couple of serial to usb adapters last night. I downloaded the proper driver for the one I chose, and it installed just fine. However, it wanted to use COM4 while the manual states that the 260 looks for COM1. Even after I got the adapter changed over to port 1, the DriveRack hangs when I try to open it. The laptop doesnt see it yet. I'm running XP home edition. All the pc installation requirements are being met. What now?

Adrian

Click to expand...

Might want to re-install that USB-serial driver, and let it default to COM4.

Then config the DriveWare app for Com4 and see if that does it.

And just to check, you do have the proprietary DBX driverack rs-232 serial cable right?
I believe it's a null modem cable.