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I have now sent two emails to Minidsp with no reply. The first at the beginning of February about the status of more order, and the second earlier this week with regards to the calibration files. No answer to either.
Not the best customer service / communication.


At this point I think I am going to get the Omnimic.
If you want the software as well thats fine, but i don't think they sell the mics seperately?

Another option is the Dayton UMM-6 USB MIc from Cross-Spectrum, although it doesn't a sensitivityfactor?

How does the UMIK form the zero gain required for absolute SPL?
 

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Okay, FINALLY today I get some time to try out my UMIK and compare it against my EMM-6
They appear to have come from the same manufacturer... housings are nearly identical (small length difference due to the balanced socket on the EMM-6 makes it a tad longer). The plastic cases, mic holder, foam filter are all exactly identical.

The sensitivity factor on my calibration file appears to be exactly 6dB too large... IOWs after I changed it from -18.5026dB to -12.5026dB it matched the EMM-6 response curve level-wise as well as agreed with my digital RS SPL meter (using Pink Noise) so I'm sure that change in the sensitivity factor was due to the modification of the electrical sensitivity that miniDSP claims they performed on the second batch of UMIKs.

It appears my two calibrated mics read essentially the same as you can see from my REW measurements just taken in our upstairs living room (the real theater is in the basement... I'll be playing around in there later tonight hopefully). The green line is the UMIK and the blue line is the EMM-6... both were in the identical same place as I swapped them in and out of a mic holder at the end of a rigid boom mic stand. Bottomline is after my adjustment to the sensitivity factor I can now trust this mic's calibration file as much as I do my EMM-6... down to 20Hz that is. Hope this helps others.
 

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The sensitivity factor on my calibration file appears to be exactly 6dB too large... IOWs after I changed it from -18.5026dB to -12.5026dB it matched the EMM-6 response curve level-wise as well as agreed with my digital RS SPL meter so I'm sure that change in the sensitivity factor was due to the modification of the electrical sensitivity that miniDSP claims they performed on the second batch of UMIKs.
Hz that is. Hope this helps others.
I have noticed the error with the sensitivity factor for the latest batch. The devteam on minidsp says that they increased the gain of the microphone by 6 dB.
This should be the reason for decreasing the factor by 6dB.

This is a silly mistake because an increase of the gain should increase the sensitivity factor instead of lower it.

I highly doubt they increased the gain at all because that would mean that the current factor is 12dB wrong instead of the 6dB you measured.
I have written about this on the minidsp forum.
Thank you for measuring this. It helped me.
 

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...I highly doubt they increased the gain at all because that would mean that the current factor is 12dB wrong instead of the 6dB you measured...
Yes, that is my guess too at this point. I'm just amazed that they didn't even look at those calibration files BEFORE they began shipping hundreds of UMIKs out the door to customers around the world... you would have thought they'd have taken all of 20 minutes to spot check just one of these UMIKs from the new second batch as soon as they arrived in-house especially since there were engineering changes made as well as modifications to the test beds and that would have caught all these errors in time to correct them thus allowing miniDSP to preserve a professional reputation... instead we now know they are unresponsive to their customers in time of crisis as well as lacking in ordinary QCing inspections of incoming and out-going product... not very inspiring and to top it off, they have now made it known that changing specs AFTER the sell is an acceptable business practice in their eyes.
 

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Really, what was there reasoning?

Some people would find this acceptable, but some not.
That's just it, there was no stated reasoning, they just did it... so apparently this is an acceptable business practice. It seems sometime during manufacture of the second batch of UMIKs it was decided that any calibration data below 20Hz was no longer to be considered reliable, so calibration files just stop at 20.1Hz... however they continued to maintained on their website that these mics still had a tolerance spec of 15Hz-20kHz +/-1dB until I asked them point blank last week how could that be? Then they just changed the spec... which leaves me to wonder how the first batch of UMIKs was able to have reliable calibration data down to 4.6Hz... or were they lying about those also?

When Hyundai was caught touting overly optimistic MPG figures, it was not thought to be okay by the government though many of their customers didn't seem to mind... however when caught in the lie Hyundai owned up to it, apologized and made monetary reparations to their customers thus keeping much of their reputation in tact.
 

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That's just it, there was no stated reasoning, they just did it... so apparently this is an acceptable business practice. It seems sometime during manufacture of the second batch of UMIKs it was decided that any calibration data below 20Hz was no longer to be considered reliable, so calibration files just stop at 20.1Hz... however they continued to maintained on their website that these mics still had a tolerance spec of 15Hz-20kHz +/-1dB until I asked them point blank last week how could that be? Then they just changed the spec... which leaves me to wonder how the first batch of UMIKs was able to have reliable calibration data down to 4.6Hz... or were they lying about those also?

When Hyundai was caught touting overly optimistic MPG figures, it was not thought to be okay by the government though many of their customers didn't seem to mind... however when caught in the lie Hyundai owed up to it, apologize and made monetary reprimands to their customers.

My opinion is that customers should be given the opportunity to return them, again some will, some won't?
 

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My opinion is that customers should be given the opportunity to return them, again some will, some won't?
Agreed, but return for a refund of the full amount including shipping both ways... however, because paying shipping both ways will surely eat up any profit that would have been gained upon the resell, many a company will balk and refuse to eat the shipping costs apparently perferring to suffer damage to reputation rather than give up any profit margin at all. And definitely no company would pay the shipping if it would result in a net loss.

In the end I'm glad the calibration file for this UMIK is accurate enough (and the sensitivity factor can now be easily adjusted, though I'm sure miniDSP will correct it for all the files soon) so these mics have some value on the used market... meaning one can resell on eBay, etc and expect to get a reasonable price for it. If the calibration files had been totally bogus these UMIKs would have much less value. BTW, I never experienced any issue with a high noise floor... hope those guys follow up on that issue when they find out the answer.
 

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Agreed, but return for a refund of the full amount including shipping both ways... however, because paying shipping both ways will surely eat up any profit that would have been gained upon the resell, many a company will balk and refuse to eat the shipping costs apparently perferring to suffer damage to reputation rather than give up any profit margin at all. And definitely no company would pay the shipping if it would result in a net loss.

In the end I'm glad the calibration file for this UMIK is accurate enough (and the sensitivity factor can now be easily adjusted, though I'm sure miniDSP will correct it for all the files soon) so these mics have some value on the used market... meaning one can resell on eBay, etc and expect to get a reasonable price for it. If the calibration files had been totally bogus these UMIKs would have much less value. BTW, I never experienced any issue with a high noise floor... hope those guys follow up on that issue when they find out the answer.

Yes for people that would like to return them (the specs not what up to some peoples purposes, 20 vs 15hz), it would be probally cheaper just to send another mic and not return the old one?

I'm glad that you are happy with the mic.
Has there been any notification that the mic files have had problems, why i ask there doesn't seem to be very much posting vs the ammount of mics sold?
Customers could be out there using the mic not realizing the problem, and how easy it is to fix.
 

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monomer thanks for your measurements, glad your findings matches mine.
Hopefully miniDSP will give there point of view on this and finally get the sensitivity factors
they published correct.
 

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I've been struggling getting a decent sound card calibration generated and finally did, hopefully if I rerun the procedure it will be repeatable. So I started working with my UMIK-1 (Ser#70000425) and when I bring up the SPL meter I get this in a quiet room:

SPL.jpg

Does this look normal? Like I have a ~ -60dB noise floor in my room/circuit? I even put the mic in it's case and partly closed it up and get the same reading so it has to be primarily mic circuit noise. My handheld SPL meter reads from the UMIK-1 and I get similar readings from 3 different computers so it can't just be the electronics on the computer side. I guess this continues to raise the question of the accuracy of the sensitivity measurement in the cal file, if I edit my file from -21.1 to -16.1 I can get it to agree with my SPL meter for the "C" weighting.

Any thoughts out there?
 

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...Any thoughts out there?
First of all since you say your sensitivity factor is still -21.1dB, I'm going to suggest you go back and retrieve your calibration file again as they've changed all the sensitivity factors back to their original readings (meaning back when those files were bogus and needed rescaling)... backstory: somehow after rescaling the calibration files, all the sensitivity factors were set to -21.1dB this was a mistake and since then they've been changed back to their original values.

Your UMIK serial# 7000425 has a sensitivity factor of -19.0671dB according to your current calibration file (I looked it up)... I suggest subtracting 6dB from that value (due to yet another mistake they made), which will make it -13.0671dB and edit your file with that value in place, now "save" the file... you will then need to "Clear" and then "Select" the file again so that REW will be forced re-load the calibration file with the new sensitivity value in it. Now check your SPL reading again. What's it reading now? A quiet room should be somewhere in the forties.

You don't need to calibrate the sound card with a USB mic. How are you connecting your computer to your receiver? hopefully you're using an HDMI connection. The UMIK is essentially 'plug-n-play' once you get the calibration file with the corrected values in place.
 

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...Has there been any notification that the mic files have had problems, why i ask there doesn't seem to be very much posting vs the ammount of mics sold?...
You noticed that too... Last week I went in search of threads about this second batch of UMIKs and found that most audio related forums on the Internet apparently don't have even a single posting concerning the UMIK at all. Of the forums that do, most threads have less than 6 posts with the last posting dated sometime in the December timeframe. It seems like the HTS is about the only place other than over on the manufacturer's forum that is even actively discussing these calibration file issues. Only later did I realize that more than two hundred of the second batch UMIKs were shipped out and I ask myself the same question you just did. :huh:
My experience over the years tells me only about 3-5% of forum readers ever post anything on a forum ever so... that would mean 8 to 12 posters should represent nearly everyone, you would think... that is IF they are reading this one thread because there appears to be no other thread even on this forum discussing these calibration file issues.
...Customers could be out there using the mic not realizing the problem, and how easy it is to fix.
This I fear is probably what's happening... in fact because miniDSP has failed to notify new owners about changes in the calibration files, many are probably still using that first bogus calibration file they'd put up. I wonder if a thread should be started with a more revealing title to attract those individuals and update them:ponder:
 

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Thanks for the info monomer...and others here. I will need to follow your instructions when my UMIK-1 mic and miniDSP 4x10 arrive in a week...hopefully.

This will be my first time using any of this software (mic or REW or plug-in) and I have no other measuring instruments or software. With that said, if there is any way I can contribute any further information to add to what is already known I will. Just let me know.
 

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At the time of purchase were you aware that the specs for the umik-1 were 15hz-20khz? If so, then you can't really complain about not getting calibration data below 15hz. But you can complain about not getting data for 15-20hz. Whether 5hz is enough to warrant a refund is open to opinion though. If it was me and a customer was complaining about 5hz of calibration data I probably wouldn't be too thrilled about it :spend:...
Interestingly I was looking at a UMIK-1 flier the miniDSP guys stuffed in the box together with my miniDSP module... apparently I was wrong, it was worse... what I thought was 15Hz turns out to be really 5Hz... yes, that's what the UMIK-1 flier has on it! It says 5Hz-20kHz +/-1dB and then they show an example calibration file that goes down to 4.6758 Hz. I must have envisioned seeing a 1 in front of the 5Hz. I am still awaiting a response from them as to what my options are.
 

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...This will be my first time using any of this software (mic or REW or plug-in) and I have no other measuring instruments or software...
Tell me 'bout it... I too have a miniDSP which I won't be able to play around with until spring break (coming up in two weeks). However I have been using REW for years and I've also been playing around with the miniDSP plug-in and it seems simple enough to configure (in fact, that was the reason I purchased it). I too am in Michigan... Reed City, you anywhere close by? If you are I might be able to assist if you get too frustrated.
 

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Tell me 'bout it... I too have a miniDSP which I won't be able to play around with until spring break (coming up in two weeks). However I have been using REW for years and I've also been playing around with the miniDSP plug-in and it seems simple enough to configure (in fact, that was the reason I purchased it). I too am in Michigan... Reed City, you anywhere close by? If you are I might be able to assist if you get too frustrated.
I'm in Cheboygan. Thanks for the offer but I ship out in three weeks and won't be back home until the middle of July. The miniDSP plug-in does look pretty simple and like you, was part of the reason I went with it. I've already made my rough adjustments for crossover points ans specific driver corrections. I should be in the ballpark already. Now I just need to wait for it to arrive.

Do they send you an e-mail when they actually ship it? I ordered my and haven't heard anything accept the order confirmation they sent. How long did it take for you to get yours monomer?
 

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Yeah, they will send an email from Customer Service-miniDSP and in it is a link to HongKong SpeedPost and your tracking number. Click the link and paste in the tracking number. You will get that email the day they ship and within a day it will leave Hong Kong and appear to arrive in the U.S. within hours but that I believe is because of it is actually crossing the International dateline (as they fly back into yesterday). In any case, at some point its handed off to either USPS or some other stateside delivery service. My UMIK was shipped on a Thursday and arrived by DHL carrier that Saturday. My miniDSP also left on a Thursday but was handed off to USPS on Monday, which was President's Day so they weren't moving anything... it was finally delievered on Wednesday and has been sitting on my desk ever since. My particular set-up is going to be quite complex... four subs (two mid-bass units and two ULF units... so they will need to be crossed over) and I will be trying to find the best compromise for in-room bass response across 8 seated locations in a two tiered layout. It actually sounds pretty good right now with just an Audyssey Multi-EQ calibration but I want even better if I can get it. I'm estimating it will take me several days to get it right and once I get started on something complex I don't like to lose my focus until I'm satisfied I'm finished... that's why I'm waiting for spring break, when I'm at home and the wife's at work.
 

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Wait so I haven't read the whole thread I'm sorry. Did the first batch of mics have bogus cal file sensitivity?

And what are the dates for the first and second batches?

Thanks guys!
 
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