Dirac / XMC-1 F.A.Q. (work in progress)

[geebo]

Wow, never had to go through any of that on two laptops with the original or UMIK mics. Must be something somewhere causing a conflict with your setup. I only have to click the Dirac icon and I'm good to go.

[klinemj]

Same here...never had anything like that! I have just hooked it up and run it.

Mark

[wilburthegoose]

Me either - Works perfectly with my desktop, but I didn't want its sound to interfere with the recording. All good

[danfan78]

I recently mic'd my room with Dirac for the first time. I have a few questions:
1. I own a Velodyne FSR-15 subwoofer. It does not have an LFE input, but has L and R inputs instead. I set the XMC-1 to stereo sub and connected a patch cable from both sub outputs to the L and R inputs on the sub. Dirac treats it like two subs during setup. Would I be better off using dual mono or connecting a Y adapter to the left subwoofer output instead?

2. I was amazed at how much correction for each channel that Dirac's PEQ accomplished and how close the corrected signal is to the target. There is an issue with my right main dropping down several dB at 200hz after correction. I'm sure that is due to my L-shaped couch causing an obstruction. When I used my DBX in the past, that same dip was there. However, I could "fix" the problem with the custom PEQ in the DBX. Is there a way to fix the same issue with the PEQ when using Dirac? I know that the additional filters in the XMC-1 are not available in Dirac mode. Just curious if I could actually manipulate the PEQ for that channel in Dirac.

I am on firmware version 4.1 on the XMC-1 and running Dirac Live Full.

3. I have a pro mic boom stand that I use for mic placement. When I used it for the Emotiva mic, the USB mic cord was too short because I am running Dirac from my HTPC which is in the rack. Is there a longer USB mic cord available or can a USB extension cord be used with a calibrated mic? I have a 25' pro XLR mic cord that I used with my DBX gear. Could I plug that into the USB mic cable and into the Emotiva mic or would it screw up the calibration? If I could do that, I'd have all the cord I ever needed!

[emofrmcgy]

Mar 21, 2018 23:47:47 GMT -5 danfan78 said:

I recently mic'd my room with Dirac for the first time. I have a few questions:
1. I own a Velodyne FSR-15 subwoofer. It does not have an LFE input, but has L and R inputs instead. I set the XMC-1 to stereo sub and connected a patch cable from both sub outputs to the L and R inputs on the sub. Dirac treats it like two subs during setup. Would I be better off using dual mono or connecting a Y adapter to the left subwoofer output instead?

2. I was amazed at how much correction for each channel that Dirac's PEQ accomplished and how close the corrected signal is to the target. There is an issue with my right main dropping down several dB at 200hz after correction. I'm sure that is due to my L-shaped couch causing an obstruction. When I used my DBX in the past, that same dip was there. However, I could "fix" the problem with the custom PEQ in the DBX. Is there a way to fix the same issue with the PEQ when using Dirac? I know that the additional filters in the XMC-1 are not available in Dirac mode. Just curious if I could actually manipulate the PEQ for that channel in Dirac.

I am on firmware version 4.1 on the XMC-1 and running Dirac Live Full.

3. I have a pro mic boom stand that I use for mic placement. When I used it for the Emotiva mic, the USB mic cord was too short because I am running Dirac from my HTPC which is in the rack. Is there a longer USB mic cord available or can a USB extension cord be used with a calibrated mic? I have a 25' pro XLR mic cord that I used with my DBX gear. Could I plug that into the USB mic cable and into the Emotiva mic or would it screw up the calibration? If I could do that, I'd have all the cord I ever needed!

1. Definitely the Y adapter

2. You “could” change the target curve for a sharp boost at that frequency. You may end up running out of amp power with more than a few dB of upward correction.
Unless the null is audible, I’d leave it alone. But I’ve taken to the ignorance is bliss outlook this last year or so.

3. Try it see what happens. Worst thing would be you need to redo your measurements. I never had that issue as I always used a umik-1 with my xmc.

[danfan78]

Y-adapter--as in connect it to the left sub output (set to mono) on the XMC-1 then to both patch cables going to the subwoofer?

[emofrmcgy]

Mar 22, 2018 22:05:22 GMT -5 danfan78 said:

Y-adapter--as in connect it to the left sub output (set to mono) on the XMC-1 then to both patch cables going to the subwoofer?

That’s how I’d do it.

I’d try just connecting the left sub out from the xmc to the left input on the sub. I have on OLD vivid 12 in my living room that I have connected this way. I also tried the y connector to the left and right inputs on it. It didn’t make any audible difference in my testing. The velodyne May be the same.

[danfan78]

Mar 22, 2018 23:08:41 GMT -5 emofrmcgy said:

Mar 22, 2018 22:05:22 GMT -5 danfan78 said:

Y-adapter--as in connect it to the left sub output (set to mono) on the XMC-1 then to both patch cables going to the subwoofer?

That’s how I’d do it.

I’d try just connecting the left sub out from the xmc to the left input on the sub. I have on OLD vivid 12 in my living room that I have connected this way. I also tried the y connector to the left and right inputs on it. It didn’t make any audible difference in my testing. The velodyne May be the same.

Yeah, it depends on the input stage and the amplifier setup for the subwoofer. The Velodyne has low-level stereo pass-through and the last sub I had that was designed that way required signal on both channels.  I'll try it and see.

[shaggy13]

I have two Sunfire HRS subs with automatic signal-detection circuits and after running Dirac both of the subs constantly come on and off during any content I play with a thump and click sound when they cycle into standby and then back on. I wonder the best way to handle this I have gone to the levels in Dirac and increased them by 7db to get them to stay on but this gives me over powering bass now. Please any advice would be appreciated. Thanks

[Jim]

Jun 14, 2018 15:01:15 GMT -5 shaggy13 said:

I have two Sunfire HRS subs with automatic signal-detection circuits and after running Dirac both of the subs constantly come on and off during any content I play with a thump and click sound when they cycle into standby and then back on. I wonder the best way to handle this I have gone to the levels in Dirac and increased them by 7db to get them to stay on but this gives me over powering bass now. Please any advice would be appreciated. Thanks

Can you disable the detection circuit so it’s always on?

If they’re going into standby when they shouldn’t, it sounds like possibly poorly designed signal detection circuitry.

[shaggy13]

It can’t be disabled I’m guessing that Dirac lowered the signal when the bass content is low or not there and you may be righ,t about being poorly designed.

[bluescale]

And I take it if you disable Dirac, the problem goes away?

[shaggy13]

That is correct but the Dirac makes the whole system especially the sides and rears sound so much better.

[tbro49]

I am getting this error message when running Dirac Full: REC2IMP_IMP_START_IMP_is_NEGATIVE. I've searched for a thread that might address this error but cannot find anything. Anybody know what this means and what to do?

[donh50]

Jun 14, 2018 15:01:15 GMT -5 shaggy13 said:

I have two Sunfire HRS subs with automatic signal-detection circuits and after running Dirac both of the subs constantly come on and off during any content I play with a thump and click sound when they cycle into standby and then back on. I wonder the best way to handle this I have gone to the levels in Dirac and increased them by 7db to get them to stay on but this gives me over powering bass now. Please any advice would be appreciated. Thanks

You might try turning down the gain on the sub, which will force the XMC-1 to increase its output level, and see if that makes the problem go away.

If you can set the subs to always on you could use a smart power strip to turn them on and off with the processor.

[tbro49]

Thx. Will give it a try. Are you referring to the gain on the sub, not in Dirac?

[tbro49]

Very frustrating. Adjusted subs and successfully ran first position then got too much clipping error for 2nd position. Adjusted subs down very slightly to once again set them right at the center of green and then got the "start idx is negative" error again. Does anyone know what this error means? I am assuming it has something to do with the signal being too low. When I make a slight adjustment to the subs up I get the clipping error again. I have checked the other settings , watched the level as the test ones are run and do not see anything that falls outside the middle green. Any ideas? 

[tbro49]

Oops. I thought Dohn50 was responding to me. Scratch my second post. Duh. Still need help, though.

[donh50]

Sept 18, 2018 15:48:26 GMT -5 tbro49 said:

Thx. Will give it a try. Are you referring to the gain on the sub, not in Dirac?

Sorry, I've no idea what your error message is, but doubt changing sub gain will help. I quoted a previous poster.

I have sent emails to Dirac with questions a couple of times and gotten fairly quick answers; I would try that.

[tbro49]

Thanks. I realized after I replied that you were responding to someone else with a different issue.