XMC-1 Level issue

[xsilverjag]

I just purchased a used XMC-1 on the forum, got it in yesterday. I purchased a full copy of Dirac and installed it on my laptopFirst thing I did was go through the setup instructions

I purchased a full copy of Dirac and installed it on my laptop.The first thing I did was go through the setup instructions. One problem is I am having is despite that fact that I ran through the procedures in the software to set the levels, the levels are massively off when I test them through the preamp itself when I test it with a SPL meter. Do you guys have any hints on how to correct the issue or do I need to send my mic in for calibration? 

THANKS~!

[millst]

The levels get equalized across the measurement area so they probably won't be dead on at the MLP. If they are different more than a couple dB, then something is probably off. Are you sure your SPL meter is accurate? If so, you might not have good measurements and should retake them.

You can search around and find advice about properly taking measurements. The gist is always take all measurements and spread them around the listening area (including slightly outside it and varying in height).

-tm

[xsilverjag]

So far I have done a factory reset and reran Dirac 4x times. On Monday I will call tech support. The center was off over 12 db and the sub was massively off I guess on Monday I will call technical support.

[qdtjni]

Where they that much in relation to the other speakers or the reference signal at 65, 75 or 85 dB?

If to other speakers, just to make sure, this is in Level is in the Dirac speaker preset?

[socketman]

Microphone position can cause all sorts of problems. In my last place one end of the couch was closer to the wall than the other ,i finally just tightened up my measuring locations. You will have to futz a round a bit to find what works for you. Also there is a bug of sorts i read about with regards to changing your speaker settings after running dirac. I had this issue so after running Dirac i did a factory reset and myleft and right speakers were once again balanced.

Search for threads by Ansat, there is a lot of info to read about Dirac on these forums. I had a bunch bookmarked but cant seem to find them anymore.

[millst]

If you're using the Emotiva provided calibration file, it is not flat. If I remember correctly, it rolls off the bass, which might account for your subwoofer level.

-tm

[xsilverjag]

Where can I find other calibrations files for the emotiva mic?

[klinemj]

Apr 17, 2017 14:48:18 GMT -5 xsilverjag said:

Where can I find other calibrations files for the emotiva mic?

Tony (ansat) created one. I believe you can find it at the end of the 1st post of this link: --->LINK<---

Or, if you order Dirac Full and a calibrated mic, you can use the cal file that comes with that mic.

Mark

[socketman]

In that download are 2 files one is a file created for the EMM1 microphone by cross spectrum labs and one that tony made and the necessary instructions.

[goozoo]

I haven't played around with DIRAC for some time (someone feel free to correct me here), but I believe the levels are reset in relation to the reference speaker (left front).  When you are setting your levels manually, you are using a SPL meter as the reference and setting the output level of the speaker in "reference" to that.  The issue with the sub has to be addressed differently as it kills too much of the low end.  Once your calibration is complete, you do have the option of increasing the individual levels of the speakers, but keep in mind that you will likely hit distortion (and/or popping) with just a few dB boost due to the way the levels have been calibrated.  For this reason, it is best to set your levels where you want them before running DIRAC and then making slight adjustments once you're done (post-calibration).  An easy way to determine how off you are ultimately is how much (if any) you need to turn up the volume (in comparison to before).  If it is a lot, then it means that there were a large number of peaks that DIRAC was attempting to correct due to either the in room response of the speakers, or the way you took your measurements.  We do a lot of room calibration for clients and the common error seems to be over correction or measurement anomalies.  Once again Ansat has a good tutorial on this and is probably the most knowledgeable about DIRAC.  It might also be helpful if you did some additional reading on this topic (room acoustics), as it will help you to better understand the graphs DIRAC produces and where you room needs correction.  

[socketman]

The odd thing with what i was experiencing was that even after setting the levels with a SPL meter (calibrated and purchased from Cross Spectrum) my system always sounded like it was biased to the right speaker. Now i even considered it was my hearing my sons all said the same thing. I found a thread on this forum which described this exactly and the solution was to reset the xmc-1 ,which does not have any effect on Dirac. After a reset and redoing my settings i no longer hear this bias. I wish i could find those threads again that i bookmarked but somehow i lost them when i started using chrome.

[klinemj]

Another thing this reminds me of...if you set levels at a point that some measured results would dictate that getting a target response required clipping, Dirac will adjust all levels down to the point that will not happen (if I recall correctly...).

Said another way...if you look at the pre-adjusted results and you have a big dip on one or more speakers in a particular frequency range, Dirac will not just boost that to the extent clipping results. Instead, it backs down other speakers until it finds a good balance. Look at your speaker by speakers results...they may be telling you something (again, if I recall correctly!)

Mark

[goozoo]

In talking with one of our audio engineers this evening who has more experience with DIRAC, he had the following recommendations:

• Invest in a different calibration mic with a proper calibration file (UMIK from miniDSP comes to mind)
• Ensure that your input and output levels in DIRAC are set properly for the mic as well as your speakers
• Verify AGC is turned OFF and mic input is at 100% in Windows if on a PC
• Measurements must be taken no greater than 8-10 inches in height from one another and be meticulous about  positioning.
• Measure everything with another software (e.g. REW) post calibration from at least the MLP and adjust accordingly

The problem with this kind of software (as great as it is), is the steep learning curve the overall topic requires to obtain the results that the person is looking for.  For most, this is more than they want to get into and instead just run the auto mode with the results they decide to live with.  What is nice about DIRAC is the flexibility it provides the user to custom tailor the sound based on their experience level.  Don't be afraid to experiment.  In time, you will have developed different settings for different scenarios that you can switch on the fly. 

Incidentally, mine is biased towards the left and I can't get rid of if no matter how many hard resets I do...thank God for external DSPs .