Home Theater Forum and Systems banner

301 - 320 of 887 Posts

·
Registered
Joined
·
1,298 Posts
We all make mistakes, but the key is how and fast we correct them.

I think the problem is that they didn't change the specs until after the consumer first bought it up. Ideally you would hope they would back the consumers opportunity to return there mic if it is not going to fill there needs due to this?

Will be interesting to see.
 

·
Registered
Joined
·
79 Posts
The problem I have is that there has been no communication to owners outside this thread and briefly on their forum. If you didn't check, you wouldn't know.

I'm on my second Umik (the first died), and whilst Minidsp did ship the replacement with no questions asked, i'd expect them to notify those with the new batch.

I only found out because John (Hifizine) asked me how the new mic was going and i told him I was getting a weird boost.

The sensitivity issue also bugs me.

I have a bunch of Minidsp products, but this and the issues with differing EQ results for different plug-ins gives me pause
 

·
Registered
Joined
·
15 Posts
sonic_blue...
Don't get me wrong, I realize mistakes and goof-ups sometimes happen and that's just a part of business but I do concern myself with is how the problem is resolved, that ultimately will tell me something about the company and if I'd be willing to do business with them in the future. I actually ordered a miniDSP from them (before receiving my UMIK) , it just hasn't been delivered yet (...today hopefully) and I'm pretty excited about it. Once I have it in hand and see that its working properly (and I have no doubt it will)... only then I will inquire directly to miniDSP to ask if they will accept a return of my UMIK on their dime (meaning they pay shipping) and I will explain my reason as due to false advertising at the time of the purchase... and see where it goes from there. (IF they do approve the return I intend to then purchase a calibrated UMM-6 from cross-spectrum).

I don't think the UMIK is a bad deal and expect it to be as good as my EMM-6, its just that I don't need it if I can't get a calibration file with it that goes below 20Hz. Its already down -2dB as it crosses 20Hz so without any calibration it most likely is easily off by over 2dBs and who knows how much more at anything lower. My basement theater is a highly treated acoustical space... do I absolutely NEED to tune my subs' low end response accurately? nope, I agree its not critical but why do I need two mics with the same range of accuracy? I just feel it was a waste of money spent being as I already own an EMM-6 that is calibrated to 20Hz and also have a RS digital SPL meter.
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:

If it were a legal case, I don't think you could argue that because the previous batch had calibration data all the way down to 0hz that therefore they are obliged to provide the same calibration data for the current batch. Because, nowhere in the product specs does it say you will get calibration data outside of the range specified.
 

·
Registered
Joined
·
26 Posts
Hi,
as already known, minidsp has been published the new calibration files for SN#7000190-7000439.
Ok here is the comparsion of these 250 cal-files. Look here for the "older ones".

Now they look more similar to calibration files (see 500 calibrations of different mics: http://www.hifi-selbstbau.de/index.php?option=com_content&view=article&id=367)
Four mics are a little bit out of range (267, 342, 344 and 406).

View attachment 40638

What is very interesting all files have zero dB at 990 and 1002 Hz.
View attachment 40637

Edit: Last Friday my UMIK arrived. It has been pending with customs 4 or 5 days. So the delivery duration was about a week. There was no tax but importation VAT of 19% ~ 15 Euro.
Thanks for putting together this information dezibel. Looking at the 0 db at 990 and 1002Hz, could it be that because 1KHz is the "accepted" middle of the 20Hz to 20KHz scale, this area was the zero point for the calibrations? I've read that in reality, the center of the scale is actually closer to 640Hz.
 

·
Registered
Joined
·
8 Posts
Hi Rob41. Normalization [email protected] is usual (see the link to hifi-selbstbau.de). The arithmetic average is (20000-20)/2= 9990 Hz. This has nothing to do with the measurement method and of course the scaling - it's logarithmical.
I guess what you see at 640 Hz is about the middle of the scale. Exactly the middle is at 634 Hz. This is because there are 559 measurement points - from 20 Hz to 20 kHz.
 

·
Registered
Joined
·
169 Posts
The sensitivity values has been changed when I looked today but can they be trusted?
Good question... mine went down to -18dB but others have gone up to as high as -26dB and that was after looking at only 10 files. I don't think the whole first batch of UMIKs spanned that much sensitivity variation between files but then I didn't look at every single file in that first batch, only spot scanned about 40 or so several days ago and those seemed to range between -14.3 dB to -16 dBs or there 'bouts. All these changes cropping up without much explanation forthcoming even on the manufacturer's forum leaves one with more questions than answers about what exactly went wrong with the second batch's calibration files and speaks to your concerns which prompted your question "...but can they be trusted?" that's a question even those with first batch UMIKs might now be asking as well. I no longer know what the he*ll is going on with these UMIKs... I now just wish some offical representative of miniDSP would speak up about these 'silent' updates (the whys and hows of what's being done behind the scenes with each change) to those of us who've already purchased one of their mics to calm our growing fears about the accuracy of these ever changing calibration files.
 

·
Registered
Joined
·
169 Posts
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:...
Unbelievable!!! So its now a question of how important is the range between 15-20Hz? Its important to me but apparently not to you... but somehow you missed the real point which is I AM NOT TO BLAME FOR THE MISLEADING SPECS... somehow its more convenient to blame the customer isn't it? It certainly costs less. Explain again... HOW WAS I TO BLAME EXACTLY?

HISTORY OF EVENTS:
I just purchased a mic according to my needs based upon their published specification at the time, only to have it arrive, find out there was a strange problem with the calibration files they put up and so I mentioned it here and start a thread on the miniDSP forum to call it to their attention while also inquiring about these calibration files ending at 20.1Hz while their specs claim otherwise... YES, I was the one who brought all this to their attention as well as your's!!! They conveniently ignored my question about ending the file at 20Hz despite rescaling the files... only AFTER I questioned them again directly on their forum about their specs on their website do they suddenly (WITHOUT notifying any of their customers) change the specs to accomodate their "new" calibration methodology which BTW was also done WITHOUT telling anyone that's what they'd decided to do on the second batch of UMIKs (the decision was apparently made a while ago too). Is this really being honest and forthcoming on their part? Then someone inquires about the unvarying sensitivity factor and without responding to this poster's question they suddenly (again, WITHOUT notifying any of their customers) change all the sensitivity factors. Wouldn't it have been more prudent to email all customers who've already purchased a UMIK from the second batch to call their attention to the fact that there are newer more accurate calibration files now online? Do you see a pattern of behavior occurring here? Its slowly becoming apparent that these new UMIKs had undergone significant changes in manufacture and calibration yet they failed to QC a single one of these new mics before they were all sent out to us, apparently we are now their beta testers. Amazing, just amazing. Now, a couple of new owners of these mics have noticed an unusually high noise floor apparently coming from the mic itself (suddenly only now we are being told it seems the new UMIK's electronics were modified from the first batch to increase sensitivity... could this have had any relation to the current high noise floor issues? Don't know, guess we'll just have to keep tuning in to find out...)

This is beginning to remind me of that tagline from the movie Jaws, "Just when you thought it was safe to go back into the water..." Anyone thinking about purchasing a UMIK might want to wait until the smoke clears first... I'm just saying...
 

·
Registered
Joined
·
19 Posts
I have taken some measurements with my UMIK-1 and am having some strange peaks at 45hz. I played a sine wave and recorded using the RTA function. The db reported with the calibration file loaded is 88db my spl meter reports 68db, could this be down to an incorrect calibration file or am I missing something? Is there any other tests I can do that would provide a better idea as to what is going on? :huh:

I have the latest stealth calibration file loaded.

thanks.

edit: it seems my SPL meter and the mic agree on the actual db down to about 150hz after that the two readings become further and further apart. Could it be my SPL meter is less sensitive at those frequencies at around 80db? or is the mic too sensitive?!
 

Attachments

·
Registered
Joined
·
1,298 Posts
Luckily i have being watching this thread.

Due to poor customer service / communication (extremely important to a business) very unlikely i will be purchasing any MiniDSP products.

As i have said in a previous post we all make mistakes, but how we fix them is the key.

It comes down to all the new fixes, can they be trusted?

The Dayton UMM-6 from Cross Spectrum is looking a great option.
 

·
Registered
Joined
·
4 Posts
Today I compared my UMIK-1 with a SPL meter and the Sens Factor in the latest calibration file is incorrect with exactly 6 dB. If I change the supplied Sens Factor of approx -22 dB to -16 dB my SPL meter and the UMIK-1 measure identically.

How hard can it be to get it correct from the manufacturer?

At least I now know what Sens Factor to use for my UMIK.:clap:

//Birdie
 

·
Registered
Joined
·
19 Posts
hmm, I've only found discrepancies at certain frequencies. I will re-test more thoroughly tonight or tomorrow. to make sure. my sens factor is 24.x but I will try at 18.x as well.
 

·
Registered
Joined
·
218 Posts
Sorry if I am asking a question that has already been answered, but I see some problems have been mentioned over the last few pages. I ordered a UMIK-1 this AM and am catching back up on it. Are the new cal files accurate, or am I going to be running into issues that are known here but not yet addressed?

I'm a little flustered. I've been meaning to order one of these for abut a month and finally got around to it today, and now I am seeing a lot of distressing info.

My concerns are more about the accuracy >20 hz (lower would have been nice), and the above posters comments that it seems there are some issues where the sens, tilts, for lack of a better word. I'm planning on using this for set-up/integration/acoustic panel placement with REW (the built in support from REW for this was a primary motivation for the UMIK-1 one over other mic's). The mic will not be used for creating eq files in the foreseeable future, if that makes a difference.

Should I try to contact MiniDSP and cancel this order?
 

·
Registered
Joined
·
19 Posts
Ok plotted some results, please excuse the graph! I only did from 40hz as I was measuring with my speaker and the response falls off massively below this. The biggest variance is between 40hz and 100hz with up to 14dB difference., although above this the differences are linear and a lot closer together..thoughts?
 

Attachments

·
Registered
Joined
·
169 Posts
Were you using the general compensation factor (correction table) for the SPL meter?
Actually thinking about it now... that would make the difference even greater wouldn't it?
 

·
Registered
Joined
·
19 Posts
Nope no correction factor. I just don't know what to make of it. Going back to what I asked before, a comparison of the UMIK-1 batch 2 vs another calibrated mic would help clear things up..right now I have no idea if my mic is accurate or not. No weird hidden agendas, just straight up easy to interpret results.
 

·
Registered
Joined
·
40 Posts
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.

If anyone is in the market for an opened but never been used mic PM me. I would be willing to sell it for $60+ shipping. At this point I think I am going to get the Omnimic.
 
301 - 320 of 887 Posts
Top