TOPIC:

Dear All,

As some of you already know, we've been battling few issues during the release of the UMIK-1 microphone, some minor, others less trivial that we are in the process of solving. It's now been few weeks that we're into it and despite the best effort of our team, there are still some outstanding items. Although we’re still waiting on our supplier to resolve some of the calibration file related problems , we'd like to provide an update. The following post will also be emailed to concerned customers in the next few days.
Note that depending on the nature of your application, the issues covered may or may not affect you.

<strong>Current status & Shipment SN#:</strong>

- Low frequency calibration: Our initial calibration files (SN#700-0000~700-0189) provided by the microphone supplier at the factory were done down to 5Hz. After few investigation and feedback from the field, we realized that achieving accurate calibration data down @ 5hz was just not possible unless done in an anechoic chamber. Reproducing accurate data (from a speaker) at 5Hz just requires an extensive setup. In a factory floor and the quantity we're talking about, it's unfortunately not practical. For this reason, it was decided to remove the data from 5~20Hz from all calibration files. This step was taken in an effort to provide accurate data for future revision and in general no microphone will have data below 20Hz. With this said, we realize that some of you bought this microphone previous to this update to our specifications on the miniDSP website(i.e. Early Feb 2013 ). To clarify a potential misunderstanding, the microphone will still be able to perform measurements down to 5Hz. Nothing changed with that regards. What changed is the fact that the calibration file isn't provided with calibration results down to 5Hz. Hoping this clarifies. For those of you who feel it is an issue, please see below for the possibility of product return.

- Frequency spikes: For microphone between SN# 700-0190~ 700-0539, an internal modification to the input stage of the microphone ADC created some spikes close to the noise floor. Being close to noise floor (-68~-74dBFS), these spikes may have not been noticed by most of you since most acoustic measurements would be done with sufficient headroom to overcome the acoustic background noise. With this said, that is an issue that we're aware and fixed in the subsequent batch starting from SN#700-0540 and up. Few dedicated members like George posted some simple rework on the microphone circuitry (required adding a capacitor). A good documented thread is available here . If you can perform that little rework and are able to open the microphone, it's certainly worth a try since it's not a complex task. I guess it's in the good spirit of DIY audio. If you damage the microphone during the process, no worries, we can still help and your warranty won't be voided in this special circumstance. Now we don't expect all of you to be willing to do this modification and therefore we have some additional options listed below in the "Pledge to our customers" section.

- SPL meter in REW: Finally, some of you noticed that REW would not correctly report the dBSPL value in the SPL meter. With the great help of John, we've been finding an offset that now need to be carried out on both REW and the calibration file. Once a script goes on the file and modifies the value, an announcement will be made along with the request for you to "download" the REW install package. Please bear with us for this small inconvenience.

- Current batch in sale from Early April: Starting from SN700-0540 and up, we have successfully solved the noise floor issue and also improved the sensitivity of the microphone (i.e. reported showing low level). We're also glad to announce the partnership with a 3rd party testing lab in USA. CrossSpectrum will now provide 3rd party calibration services for those of you looking for it.


<strong>Our pledge to our customers:</strong>

We built the UMIK-1 product to help the miniDSP community get a plug&play and affordable measurement system. Thanks to the help of some of our partners (e.g. REW), it was made even more plug&play. However not everything always goes according plan when it comes to hardware and unfortunately in this case, it wasn't as smooth as it should be. This mishap however doesn’t change our pledge to make sure you're happy with our products. So here are some options for microphone SN#700-001 to 700-0539 at the core of the issue and with some of you finding the microphone unusable for the intended job:

OPTION ONE: Complete refund for SN#700-0190~700-0539: To simplify logistics, this offer will last for the next month (last day of processing will be May 16th, 2013). To process a refund, here are the steps:
a) Send an Email to "This email address is being protected from spambots. You need JavaScript enabled to view it." with the title "Product Recall UMIK - SN#700-0XXX" where XXX is your serial number. This process is required to initiate a recall and mics received at our office without prior email won't be accepted. Thanks for your understanding.
b) In the body of the email, please confirm the Paypal address you'd like the refund to be made to. (i.e. tied to your Paypal account)
c) In an effort to prevent a faulty microphone to stay in the field, the old microphone body (not accessories) must be shipped back to us before the refund is processed. It must be send via standard registered airmail (e.g. USPS, AirMail) in a padded envelope. You should take a picture of the receipt for the postage cost (used for refund). In some countries, cost of shipping will not make sense (e.g. higher than 20USD). We ask you to contact us in that case.
d) Once the microphone received, we will process the refund via the Paypal address including shipping costs incurred (on initial shipment + ship unit back to us).
Please contact us in any doubt.

OPTION TWO: Upgrade of internal PCB layout for noisy UMIK-1 affecting (SN# 700-0190~ 700-0539)
This option applies to those of you who are using the UMIK-1 fine but are bothered by the spikes. If you can't perform the hardware rework mentioned above, we can send you a new internal PCB which can easily be inserted inside the microphone. We are now manufacturing new bare boards but it will take a bit of time to have full stock. Note that this trick still requires a bit of hardware understanding and a soldering iron; therefore you should have a try at opening the microphone first to see if the fix is possible. It may not be for everybody.

In order to get closure on this issue, if you have some issue mentioned above, we'd like to ask that you select either Option ONE or TWO within the recommended time limit.

-> Finally, just an update to all others members that we're still in the works of communicating with our suppliers trying to remove the kinks of the calibration file. We will provide an update to you shortly. Thanks again for your patience and your support!

Hoping this info helps, if you have any questions and need some specific support, feel free to email us. Although we receive a lot of inquiries daily, our team is doing its best to answer within a short time. Note that the miniDSP forum/email is the safest bet for your message to reach us quickly. HometheaterShack or other forums are not powered/monitored by our team and shouldn't be considered as our mean of communication. Thanks for your understanding.

Hoping this info helps and have fun with your DIY projects wherever you are!

DevTeam

hello devteam
Thanks for the extensive communication.
Regarding Option Two, changing the PCB. I understand that the sensitivity is changed. Does this change the calibration file?

devteam wrote:

Dear All,

As some of you already know, we've been battling few issues during the release of the UMIK-1 microphone, some minor, others less trivial that we are in the process of solving. It's now been few weeks that we're into it and despite the best effort of our team, there are still some outstanding items. Although we’re still waiting on our supplier to resolve some of the calibration file related problems...
Our pledge to our customers:

We built the UMIK-1 product to help the miniDSP community get a plug&play and affordable measurement system. Thanks to the help of some of our partners (e.g. REW), it was made even more plug&play. However not everything always goes according plan when it comes to hardware and unfortunately in this case, it wasn't as smooth as it should be. This mishap however doesn’t change our pledge to make sure you're happy with our products. So here are some options for microphone SN#700-001 to 700-0539 at the core of the issue and with some of you finding the microphone unusable for the intended job:

OPTION ONE: Complete refund for SN#700-0000~700-0539:...DevTeam

Okay so you admit you sent out UMIKs that didn't meet the published specs and the expectations of your customers... its been 2 and half months since the second batch started shipping and now you say you want to do right by your customers now and offer a pledge.

I think its time to talk the specifics of what you are offering exactly...
A complete refund should include all shipping costs, not only the $20 that was charged to us to use Speed Post but also the return shipping and registered airmail service you're requesting for this return. Your customers purchased the second batch UMIKs good faith and instead received a defective product (regardless of if you knew about it at the time or not) therefore we should be made whole again and not have to pay any out of pocket expenses for a mistake your company made. Remember the customer played no part in you sending out defective product... in fact, we've been inconvenienced by the whole experience. So please assure me and anyone else considering a return that you will indeed refund all shipping costs associated with the original purchase and this return including the return shipping expenses. What sort of proof do you want me to provide for those costs?

My Thoughts:
In the end you should still break even (or even maintain a tiny profit margin) since you'll simply replace the board, change the serial # and resell it as a Rev C or third batch UMIK... that profit should pay for the shipping expenses you will incur on any returns and the small cost of a replacement board which I assume you will do in-house.

@ monomer,

Yes we will pay for shipping costs back and forth (hence the initial post asking for the receipt). Please read the clarified section explaining the sort of proof you need.

As for your other comments, we're unfortunately sure what else we can add here. We did try to explain to our best the above the reason for the delay, we do provide a refund in the end for all products... I'm not sure what else you're looking for here but if you have any questions, feel free to ask.

Devteam

turboman wrote:

hello devteam
Thanks for the extensive communication.
Regarding Option Two, changing the PCB. I understand that the sensitivity is changed. Does this change the calibration file?

hello devteam

I checked the calibration files on your website, and I noticed that the sensitivity factor for the mics with serial number 700-0540 and up, is different from the serial number below 700-0540.
So my interpretation -as a non expert- is, that the calibration file is not correct anymore when changing the PCB.
Can you confirm if this is correct? If yes, how do we get the correct calibration file when changing the PCB?

@ Turboman,

oops, sorry for missing your earlier post!
- The sensitivity factor is indeed changed by the new PCB, but not the frequency response. A known offset (gain) is required here. When someone upgrades the internal PCB, our team will provide a new calibration file which will have the correct offset. That's electronic input stage which is a "known" variable since it's analog/digital electronic. It's not related to acoustic (i.e. frequency response of the capsule) or "sensitivity drift" of the capsule which is once again capsule related (e.g. -20.5 or -20.8 or ...)

Does this make sense?

DevTeam

Hello devteam,

Thank you for this updated information, and for the two possible remedies.

I have microphone 700-0410, and am planning to try the remedy advanced by Georgio's work... not too scary, since I did come into this project from the "DIY" community

Is the procedure for registering for "Option Two" (receive new PCB) the same as "Option One" (return/refund)? ...that is, send in a confirming email? I'm comfortable with extracting and soldering on the board, but feel it would be prudent to have a replacement in hand if the project goes badly.

Please advise at your convenience- thank you!

Ed Henderson

dear sir,

i bought umik -1 second batch with serial no 700-0436 , the name was dr purushothaman , india and i was following all the problems and read the lattest offer from your side

my problem is i lake DIY skill to attach the board,and i have bought the mic through credit card as rules in my country doesnot allow me to have paypal account, so i cannot receive the refund and i also does not want to send back the mic because of so many logistics involved and i want to have a accurate mic also

so instead of you paying me both shipping cost,( if i have to return the mic) can you give free shipping and additional discount ( covering the shipping which you have to bear if i send the mic) for a third batch umik mic

iam ready to pay the same through the credit card and have a additional umik third batch mic

i hope you understand what iam proposing ,monetary wise it is same for both us , instead wasting money and time on shipping , i would like have additional mic by paying some extra money

it is win win situation for both of us

the air mail resgister post to hongkong to may place will be 25 dollrs apporximately

expecting the answer

devteam wrote:

@ monomer,

Yes we will pay for shipping costs back and forth (hence the initial post asking for the receipt). Please read the clarified section explaining the sort of proof you need.

As for your other comments, we're unfortunately sure what else we can add here. We did try to explain to our best the above the reason for the delay, we do provide a refund in the end for all products... I'm not sure what else you're looking for here but if you have any questions, feel free to ask.

Devteam

Thank you so much for your response. Its quite reassuring to hear you'll stand by your pledge. I've been extremely busy this week at work and haven't had time to check back here until now.

I really wanted to like this UMIK but it just seems this second batch had too many issues right from the start that never got straighten out. However it would seem the third batch that's now shipping doesn't have any of those issues. I had wanted to do an exchange but if my only choices are as outlined in your post, I'll have to choose to return my UMIK.

Thank you for all the info and providing us with choices.

I have a UMIK-1 serial #387 if I choose to go with the new board what effect will this have on the existing calibration file since the mic will not be in your possession to recalibrate. I would much prefer to be sent a new mic that has no issues with a return packing slip for the return of the old mic. To me this would be a much more acceptable solution. DIY with such a small components for me poses too much risk of damaging the mic and having to return it anyway.

Thanks in Advance.

Hello DevTeam,

I have serial number 700-0507 and I would be happy to receive a PCB to replace the current one in the mic. I'll send you an email separately as I would also like to get a MiniSharc and other items. We may as well make use of the shipping...

I have a question about the current mic. I too have found the sensitivity in REW to be very low. I know there is a calibration file change that would be needed with the new PCB - no problem.

However, my current PCB has DIP switches are in a different position than shown by your post (in the other UMIK thread) which is also different than what George posted. On my mic, with no DIP switch changes, I have all three switches in position closest to the label "ON".

http://lh3.googleusercontent.com/-VtomSPIWpZI/UW87UVeCzAI/AAAAAAAAAD8/0fI-WpE_Iso/w497-h373/13%2B-%2B1

I assume this means they are all on and provide 0 dB gain according to the silk screen chart on the back of the board. Beside the text "ON", is the text "DFF" the switch brand? It caught off guard as it reads close to "OFF", which wouldn't make sense.

Your post appears to show switches 1, 2, and 3 in the OFF, OFF, and OFF positions (36 dB gain):

devteam wrote:

Please see the diagram below as a reference for location of pads.

Regardless, while I wait for the PCB, with my current calibration file, what position should the switches be in (gain)? Should they all be off?

Thank you,


Brendon

Sorry, the image wouldn't link in my prior post in Google+. My DIP switches are shown here.



Brendon

ejh2854 wrote:

Hello devteam,

Thank you for this updated information, and for the two possible remedies.

I have microphone 700-0410, and am planning to try the remedy advanced by Georgio's work... not too scary, since I <em>did</em> come into this project from the "DIY" community

Is the procedure for registering for "Option Two" (receive new PCB) the same as "Option One" (return/refund)? ...that is, send in a confirming email? I'm comfortable with extracting and soldering on the board, but feel it would be prudent to have a replacement in hand if the project goes badly.

Please advise at your convenience- thank you!

Ed Henderson

Ed,

Option2 (i.e. receiving a new PCB) is essentially similar to doing a rework. It's really for end users that can't solder a cap on the PCB. The modified PCB has a bit of other modifications but that's mainly to modify the overall analog gain. You can easily do the same with the DIP switches (see other comments below).

One advise, have a try at adding the cap. It's really the simplest modification as already shown by George. If you have any issues or run into some problems or board doesn't work, just feel free to contact us and we'd be happy to ship you a new board. Sending a simple email to us will suffice. Makes sense?

DevTeam

drgnanam wrote:

dear sir,

i bought umik -1 second batch with serial no 700-0436 , the name was dr purushothaman , india and i was following all the problems and read the lattest offer from your side

my problem is i lake DIY skill to attach the board,and i have bought the mic through credit card as rules in my country doesnot allow me to have paypal account, so i cannot receive the refund and i also does not want to send back the mic because of so many logistics involved and i want to have a accurate mic also

so instead of you paying me both shipping cost,( if i have to return the mic) can you give free shipping and additional discount ( covering the shipping which you have to bear if i send the mic) for a third batch umik mic

iam ready to pay the same through the credit card and have a additional umik third batch mic

i hope you understand what iam proposing ,monetary wise it is same for both us , instead wasting money and time on shipping , i would like have additional mic by paying some extra money

it is win win situation for both of us

the air mail resgister post to hongkong to may place will be 25 dollrs apporximately

expecting the answer

@ drgnanam,

OK, your case sounds different to the 2 options we provided..
We see that you emailed us already. We'll answer by email to see how we can help.

Sounds good?
DevTeam

@ Boxerdog,

Our answer will be the below:

The sensitivity factor is indeed changed by the new PCB, but not the frequency response. A known offset (gain) is required here. When someone upgrades the internal PCB, our team will provide a new calibration file which will have the correct offset. That's electronic input stage which is a "known" variable since it's analog/digital electronic. It's not related to acoustic (i.e. frequency response of the capsule) or "sensitivity drift" of the capsule which is once again capsule related (e.g. -20.5 or -20.8 or ...)

Easiest if you don't want to perform the change that you select Option ONE in this case.

Hoping this answers your question.
DevTeam