[PLMONROE]

Since the Behringer DCX-2496 is used in a slightly different manner with the RM-V60s this should have its own thread.   

In looking over the Behringer while awaiting my Digilink to get things up and running I note that the frequency band is divided into three segments; 20 -223 hz, 223 - 266 hz, and 266 -  19.6 khz. This brings three questions to mind for Brian:

1) Why the third band of 223- 266 hz  instead of just two bands of 20 - 266, and 266 - 19.6 khz?
2) Since the mid bass unit does not go down to 20 hz why not set the first band pass lower limit at 40, 50, 60 hz?  This would let the amp powering that band  work a bit easier I would think.
3) Why set the upper bands top limit at 19.6 instead of allwing it to go higher (not that we can even hear to 19.6 khz but some claim this inaudible extension adds some sort of extra "aura" for lack of a better term)?
 

Paul

[Brian Cheney]

1. The mid band is not used in the two way Digilog configuration.  Use the treble band from 266Hz on up to HF cutoff.

2. Do not cut off the 6.5" in their lower range.  They need a full LF signal to function properly,

3. The treble HF cutoff defaults to 19.6kHz, you can extend it to 20kHz if you like, there is no sonic consequence.

[PLMONROE]

1. The mid band is not used in the two way Digilog configuration.  Use the treble band from 266Hz on up to HF cutoff.

Then could a pass band of say 20-80 hz or some such be set in the unused mid band to run the VLAs? aa

Paul

[Brian Cheney]

Haven't tried that, but should work.

[Housteau]

In order to do that the output configuration would need to change from Brian's standard configuration of LH LH LH to either LMH LMH, or LL MM HH.  Is that correct and will it then be possible to run the VLAs from the Behringer in a triamp configuration?

[PLMONROE]

From looking at it, it has the left preamp output going to outputs 1, 3, and 5 with the right output going to 2, 4, and 6 so it would seem 1 and 2 could feed one amp, 3 and 4 another, etc which would allow tri amping. Or am I missing something? However, I think I have a better, albeit more expensive solution which would involve no changes in the use of the Behringer. That would be to take  additional full range L and R outputs from the preamp and feed  them to a pair of Velodyne SMS-1 Digital Drives, one hooked up to each VLA. The SMS-1 can be configured as a digital pass band filter with selectable settings in one hz increments between 15 and 198 hz with slopes of 6, 12, 18.24,30, 36, 42, and 48 db/octave. Within the pass band there are 8 equalizer bands which can be infinitely adjusted to the frequency and Q one desires. Whats more for the faint of heart there is an automatic feature that only requires setting up a microphone, hitting a button, and sitting back and let the unit optimize itself to the room. Is that cool or what?

Brian, if I go that route what settings would you recommend trying first, 16 to 70  hz? What slope would you suggest?   

Paul   

[Housteau]

Looking at the manual and from what you describe it must be set to LL MM HH, which would leave the midband free.  But, are you able to select a low frequency to outputs #3 & 4 from that midband?  The manual is not specific on this and you need a unit in front of you to check.  My understanding is no, but to be honest, I am a bit confused and not sure anymore.  The output to the V60s should be 1, 5 and 2, 6, if your unit is set to LL MM HH.

[sendler]

You can set any of the channels, any way you like. All of the settings are available in any channel just the same. L, M, or H are just names to designate which channels are paired together when the link feature is selected. Some mods do make the outputs specialize for bass or treble, I usually set them up LMH LMH, but a stock DCX2496 won't care if you take the pair that is designated M and configure them for stereo subs.

[PLMONROE]

That is correct. The manual leaves a lot to be desired and is not very helpful (IMHO). Unless I am very sadly mistaken, anything connected to 3 & 4 will receive whatever parameters are set into 3 & 4. So you can set 20 to 266 hz in 1 & 2, 20 to 80 or even full band in 3 & 4, and 266 to 19.6 khz in 5 & 6.

Paul

[Housteau]

You can set any of the channels, any way you like. All of the settings are available in any channel just the same. L, M, or H are just names to designate which channels are paired together when the link feature is selected. Some mods do make the outputs specialize for bass or treble, I usually set them up LMH LMH, but a stock DCX2496 won't care if you take the pair that is designated M and configure them for stereo subs.

That is what I have always seen from the manual, but when I had asked this question in another thread with the intoductions of the SDE technology http://www.audiocircle.com/index.php?topic=54410.0, Brian responded:

"At CES we will control the main V60 wings and one sub from the DCX2496, the second sub from a Dayton sub amp with EQ.  This is because the DCX is set up for biamping a two way and one subwoofer and does not permit stereo subs.

What I suggest for you or any V60 owner is biamping the wings with the DCX and a second amp through the speakers' direct inputs, using the "digilog" adapter, rather than triamping.  I don't think triamping will improve matters and we have programs written for biamp operation with the "digilog" that took weeks to do.  I'd continue to use the Dayton amps on the VLA's, they sound good, have plenty of power, and that nice parametric EQ builtin.

The big improvements from biamping through the DCX: floor-to-ceiling room mode correction for the wings as well as for the VLA's, elimination of the mid panel 1-3kHz hump, compensation for the CDWG treble rolloff, and a few more tricks I won't discuss that are embedded in the password-protected program.

If you have an unused good quality amp for the bass section of the wings, go for it.  Otherwise amplification options have been discussed here at length."

Now, at the CES we did not do that and instead ran the Dayton mono amps directly out of the preamp parallel with the main outputs to the behringer for the V60s.  Plans do evolve over time as they should as more is learned about different options available.  I get that.  But, now there is that same conflicting information once again about connecting stereo subs to the Behringer along with biamping the V60s.  This is why I am now confused about the whole thing.  Was it just a misunderstanding of what was possible in the beginning?

[PLMONROE]

I spoke with Mike Galusha, to whom I will be forever indebted for agreeing to do one last DCX2496 mod for me. He states (if I am paraphrasing him correctly) that whatever is programed in 3 & 4 is only directed to the output connectors for 3 & 4. That being the case it would appear that the 223 to 266 hz set in 3 & 4 goes nowhere with no connectors to 3 & 4. The issue of running the VLAs directly from the preamp is that now you have to set a fixed volume on the Behringer and use your preamp volume control to control the sound level. This is OK but now it becomes difficult to consistently drive the Behringer at the level it sounds best. Life just gets tedious, don't it?

Paul

[mgalusha]

What Scott said is exactly right, any channel can have any XO frequencies and EQ applied. The LMH are just labels, running stereo subs from the MM outputs is no problem at all.

Any of the modified units that have Jan Didden's analog IO board in the, which Paul's does, need to be used in the LLMMHH configuration. This is because Jan's board allows setting the relative amplifier gain compensation and channel balance in the analog domain. The gain settings are relative to channels 3/4. In other words if the bass amps need 3dB more gain than the HF amps you could set them to +3dB in the volume control chip. This will increase the level going to channels 1/2 by 3dB. The same applies to the HF settings and the gain adjustment is routed to channels 5/6. In this case since it's used in a biamp configuration using 1/2 and 5/6 only one of them needs to be adjusted if the amplifiers have different gain. Talking with Paul he lucked out as both of his amps have 26dB of gain so no compensation was required. The balance control is configured so that left is channels 1/3/5 and right is 2/4/6. It can't be changed as this is how the board is designed and the controller code is written. Maybe one could convince Jan Didden to write a special version of the micro controller code but I doubt it.

Using channels 3/4 for stereo subs is no problem at all. You can either set them full range by simply setting the crossover filter type to "off" and allow the sub amps to handle the XO and EQ or this could be done in the DCX. Or the subs can be driven from the preamp. Personally I would drive them from the DCX so I could use the volume control of the DCX and in Paul's case use the Velodyne to handle the XO and EQ. The reason for this is that the Linear Audio analog board uses a very good sounding analog volume control chip which allows the analog signal coming into the DCX to be kept as high as possible without clipping. This will improve the signal to noise ratio vs using the preamp volume control. I know that Scott uses his attenuators after the DCX, which has the same effect in that the DCX runs with a high signal level, reducing the potential for noise. Of course this is not required and one can just set the analog output level of the DCX (modded only, not adjustable in stock units) high an use the preamp volume control. Lots of folks do this happily and it works fine. I just like to reduce noise or the potential for it as much as possible.

mike

[sendler]

which allows the analog signal coming into the DCX to be kept as high as possible without clipping. This will improve the signal to noise ratio vs using the preamp volume control. I know that Scott uses his attenuators after the DCX, which has the same effect in that the DCX runs with a high signal level, reducing the potential for noise.
mike

.
Having multi channel volume control for each output of the DCX, or at least a fixed pad on the amps inputs, is crucial to getting the best sound not only for signal to noise ratio, but more importantly for the analog conversion. As you know, just plugging the stock outputs of your DCX into good high end amps, as opposed to the pro audio amps that have their own built in volume controls for which the DCX was originally designed, gives you the undesirable situation where the analog input meters of the DCX are barely lit even though the sound level from your speakers is very loud. This causes the analog to digital conversion to have many of it's bits of resolution filled with useless zeros which yields a thicker, less detailed sound. Ideally, you want the analog input meters just tickling the top, the same as when making a cassette tape (remember those), when the music is playing at the volume you want. Or for the best sound, run digital in which eliminates the need for a good dac and preamp.

[PLMONROE]

John, 'ya been uncharacteristically quiet!  Cat got your tongue?   

Paul

[Housteau]

Having multi channel volume control for each output of the DCX, or at least a fixed pad on the amps inputs, is crucial to getting the best sound not only for signal to noise ratio, but more importantly for the analog conversion. As you know, just plugging the stock outputs of your DCX into good high end amps, as opposed to the pro audio amps that have their own built in volume controls for which the DCX was originally designed, gives you the undesirable situation where the analog input meters of the DCX are barely lit even though the sound level from your speakers is very loud. This causes the analog to digital conversion to have many of it's bits of resolution filled with useless zeros which yields a thicker, less detailed sound. Ideally, you want the analog input meters just tickling the top, the same as when making a cassette tape (remember those), when the music is playing at the volume you want.

Thank you both Scott and Mike.  These last few posts are full of some very good information that was certainly not known by me, or I would guess to many others.  I have not read any mention of this before and would venture another guess that most users of unmodified units do connect them directly to their amplifiers.

[PLMONROE]

YIPPIE!!!! Its Christmas!  My Digilink just arrived in the mail. Sure has been a long wait since I ordered it and the Behringer last September 30Th but the wait is now finely over. It looks like I should have everything hooked up in :45 minutes or so. I will post my impressions later. 

Paul

[Brian Cheney]

I understand Mike Galusha had your DCX for some time.  His full mod takes a while to install, plus he had difficulties with the audio boards.  It was your unit's vexing problems that led him to stop modding DCX's entirely.

However, you now own a state of the art preamp, digital crossover, and six band parametric EQ that will work wonders with your sound.  Just eliminating primary room modes is a huge step forward and is easy once you familiarize yourself with all DCX modes and functions.

Remember you will still have to adjust levels between bass and treble amps, since the gain of your dissimilar amps is close, but not exactly equivalent. Go slowly in 0.1dB steps for best results.

Have fun and let us know how you're doing.

[Housteau]

I understand Mike Galusha had your DCX for some time.  His full mod takes a while to install, plus he had difficulties with the audio boards.  It was your unit's vexing problems that led him to stop modding DCX's entirely.

So, its all Paul's fault.  Somehow I just knew it

[Brian Cheney]

That's the spirit!

[PLMONROE]

Brian earlier I shared the secret of my middle name with John but I haven't with you or Dave. It is Weft (Wrong Every Flippin Time - or something like that)!  aa