TOPIC:

This is my 2nd DDRC-24 and I simply can't figure out what I am doing wrong after all my experience with my first DDRC-24 which I had no problems using Dirac Live. Set ddrc-24 into USB mode connected to Windows. I launched Dirac Live and set the volume calibration master volume to -32db, so that each channel is picking up roughly -25.5db which sounded loud enough to do a calibration. Go on to measure and suddenly I barely hear the signal through my speakers. Going back to the volume calibration its back to -95.5db on the master volume. No matter what I do, it won't stick to -32db which is really the level I need it at. What am I doing wrong?

I had first tried it on a Mac OS and thought it was an issue with Mac and then tried it with windows and the exact same issue. This is driving me nuts.

Are you using the most up to date firmware and plugin? Check the user downloads section if you're not sure.

Ultrasonic wrote:

Are you using the most up to date firmware and plugin? Check the user downloads section if you're not sure.
 

Yes, that was the first thing I did upon getting the new unit. Plug in version 1.16 FW 1.17 and Dirac Live 3.3. In fact the windows 10 was a clean fresh install just to solve this problem. I tried MacOS first before switching to a windows installation.

I just tried out the miniDSP on another system of mine (I have four, with 1st miniDSP to the main setup, and this 2nd one was for system #2). On this 3rd system DIRAC worked - the sweep signal was of sufficient strength and I was able to successfully complete the calibration. So the only difference between this 3rd setup and the 2nd setup is literally the amplifier. #2 is a class A tube amplifier (Nobsound 6P1) while #3 is a SMSL DA-9. Other than that, everything is exactly the same - same laptop, same cables, same mic (UMIK-1), and nothing in between the miniDSP and the amp and signal being fed through miniDSP USB inputs. The only thing this could mean is that the input signal to the Class A amp is insufficient, but it was at MAX volume and gets plenty loud at that despite only pushing 6w/channel to my Klipsch RP-280 which has a sensitivity of 98dB. I have no idea why the amp the miniDSP is connected to can make this kind of difference.

I am also having this issue with my DDRC-24.  Have updated firmware and re-installed software but whenever I proceed past setting the master volume and levels, it reverts back to -95.5db.

Any suggestions?

Podmore wrote:

I am also having this issue with my DDRC-24.  Have updated firmware and re-installed software but whenever I proceed past setting the master volume and levels, it reverts back to -95.5db.

Any suggestions?

 

From what I understand, going back to the volume calibration screen always resets any changes to master volume or mic levels. In my case, the sweep signal was extremely low only on my Class A tube amplifier (Nobsound 6P1). It works ok on other amplifiers (SMSL DA-9, and DA HTA100BT), leading me to believe that it may have something to do with impedance mismatch (DDRC-24 has output impedance of 560 ohm and my amp's input impedance is 100K ohm, which should have been ok, but I guess most amps have input impedance in the 20-30K range rather than 100k possibly making the amp harder to drive). I put a pre-amp in between the DDRC-24 and the amplifier (set at no gain or attenuation) and it solved the problem. If you have a neutral pre-amp like the Topping L30 and RCA cables, I would recommend trying to put that between the DDRC-24 and your amp or downstream equipments.

Thanks for the suggestion.  I am running right into my SMSL SA-98E with volume set at 50%.  Levels are otherwise great, and I am able to set and get good levels when doing the volume calibration.  Just when it comes to the sweeps there is only the faintest sound coming through.  Surely if it was an impedance mismatch I woudnt be getting sufficient levels to get normal audio through.  A bit stumped as to why.

Podmore wrote:

Thanks for the suggestion.  I am running right into my SMSL SA-98E with volume set at 50%.  Levels are otherwise great, and I am able to set and get good levels when doing the volume calibration.  Just when it comes to the sweeps there is only the faintest sound coming through.  Surely if it was an impedance mismatch I woudnt be getting sufficient levels to get normal audio through.  A bit stumped as to why.

 

It could be a combination of both impedance mismatch and input sensitivity on the amp side resulting in the same problem - the volume levels on the volume calibration screen was loud enough, but the actual sweep was much fainter. I am entirely guessing here, but I don't think the volume calibration is representative of the actual sweep signal strength. All it might be doing is increasing a very low sweep signal strength proportionally to the gain you set in the volume calibration screen (say you increased the gain by 2x, then the sweep signal would also increase 2x, but not match the actual sound levels) which might still be insufficient. I was expecting the sweep signal strength to sound as loud as the volume calibration, but thinking through all the calibrations I have done in the past (quite a few over 6 months), I now believe that is rarely the case. By introducing a pre-amp, you get better input sensitivity downstream which allows the sweeps to sound sufficiently louder.

I wish this disconnect between volume calibration levels and actual dirac sweep levels is properly documented as this is likely causing the most frustration for us. Also, a popup dialog informing that the volume calibration screen that levels have been reset whenever you visit that screen would clarify that it is by design rather than a DIRAC bug. Obviously, this falls into the DIRAC documentation, not miniDSP.

vvume wrote:

This is my 2nd DDRC-24 and I simply can't figure out what I am doing wrong after all my experience with my first DDRC-24 which I had no problems using Dirac Live. Set ddrc-24 into USB mode connected to Windows. I launched Dirac Live and set the volume calibration master volume to -32db, so that each channel is picking up roughly -25.5db which sounded loud enough to do a calibration. Go on to measure and suddenly I barely hear the signal through my speakers. Going back to the volume calibration its back to -95.5db on the master volume. No matter what I do, it won't stick to -32db which is really the level I need it at. What am I doing wrong?

I had first tried it on a Mac OS and thought it was an issue with Mac and then tried it with windows and the exact same issue. This is driving me nuts.
 

I reached out to miniDSP support and they correctly identified the issue - apparently my mic levels were low. I had no idea that mic gain levels affected how the master volume behaved. Just to wrap up this thread, this should be prominently splashed at the very top of the DIRAC Live user manual and on their webpage. Not knowing this causes considerable headache:

• Mic gain may affect sweep volume. Ensure both master volume and mic gain is increased until you hear a sufficient sweep signal.
• Once you move away from the volume calibration screen and revisit it, it will reset all values. This is by design.
• Saving the project does not save the volume calibration levels.
• The actual sweep volume levels may not match the volume levels heard on the volume calibration screen.

 

So I ran into this same problem last week when trying to reset things after getting a new computer and accidentally deleting my configs from the miniDSP unit. It was super frustrating, but I inadvertently ran into a way to get it working. I had my MacBook attached to the miniDSP via USB, and I had the miniDSP set to use USB on the inputs. With this configuration, I kept experiencing the same low-volume issue when trying to run the measurement sweeps. I'm not sure what made me think to do this, but I switched the miniDSP input to "Analog", and then I ran Dirac again (obviously still connecting through the USB cable). This time it all worked just fine. After doing the measurements and updating the Dirac config on the miniDSP, I switched its inputs back to "USB", and everything works fine now.

My 2 cents: had the same issue, I'm on a Windows laptop. Definitely mic works fine in Windows, Dirac app has access to it, during Volume Calibration levels are changing depending on output, but when I proceed to measurements, the test tone is too silent. Restarting Dirac and DDRC-24 didn't help.
In my case the problem just disappeared itself after a coffee break and closing the laptop. So no idea what happened. I didn't reboot the laptop, didn't power cycle Flex. So I guess redoing some stupid things like plug-unplug, open-close stuff. somehow did help. Magic.

That solved it. I think it is a bug.