low, mid, high price microphones for DIRAC & what their effect to the end result

[Narukama]

Hi, I read in DIRAC website there are 3 recommended microphone for DIRAC:

1. miniDSP UMIK-1 microphone around $75

2. XTZ Microphone Pro around &170

3. Earthworks M23 around $459 + Phantom Power?

 

My question is, if DIRAC is used for 2 channel audio system and 5.1 HT, using those 3 microphones, would the sound quality end result (after being optimized by DIRAC) be quite different? Or the result will be the same since all the microphones are calibrated?

 

If there will be a difference in sound, what one should expect by using affordable UMIK-1, medium price XTZ and expensive M23?

 

As a newbie I don't mind invest in M23 but only If the end result would be significantly better than say the UMIK-1.

 

I really appreciated if someone would explain to me in layman term and surely hoping to hear from someone who has tried those 3 microphones.

Other brand and type suggestion as additional option are also welcome and needed.

 

Thanks and Cheers,

Narukama

[firedog]

I don't think you will find much difference if you are only using the microphone to make a measurement file for DIRAC. I asked 2 companies that sell different mics about the UMIK, and they both seemed to think it was more that adequate for the purpose.

 

I used to have a TACT RCS preamp, and used the stock mic and an expensive measuring mic. Didn't really think it made much difference.

[iago]

Or the result will be the same since all the microphones are calibrated?

 

I have to disappoint you, the microphones are not calibrated. Dirac will just deliver a (generic) calibration file. This is something completely different.

 

You can use any microphone meeting the specifications mentioned on Dirac's web site (omni-directional small-diaphragm microphone) if you know it's exact frequency response. You can spend quite a significant amount of money and buy a class 1 (see IEC 61672) measurement microphone - here the manufacturer guarantees a frequency response within certain parameters. Or you buy an inexpensive one and have it calibrated as a service. Ideally you send them the microphone together with the amplifier, because it also has an influence on frequency response.

 

Avoid microphones wich come with generic frequency graphs or files (some of the inexpensive ones like t-bone have them), they are useless. Some compamies sell already calibrated microphones, these are perfect. iSEMcon in Germany is one of them. Buying your own microphone and having it calibrated is still more cost effective.

 

To give you an example why calibration is necessary, take a look at some diagrams. The example is taken from a German periodical (sorry, the text is in German) targeting the DIY speaker community. They also offer microphone calibration as a service and show a summary of the calibrations they did over the last years. You will find some popular brands and their deviations due to manufacturing tolerances.

 

 

As you can see from the various graphs in the link, the biggest deviations from the ideal frequency response occur below 50 Hz and above 10 kHz.

[Narukama]

I have to disappoint you, the microphones are not calibrated. Dirac will just deliver a (generic) calibration file. This is something completely different.

 

You can use any microphone meeting the specifications mentioned on Dirac's web site (omni-directional small-diaphragm microphone) if you know it's exact frequency response. You can spend quite a significant amount of money and buy a class 1 (see IEC 61672) measurement microphone - here the manufacturer guarantees a frequency response within certain parameters. Or you buy an inexpensive one and have it calibrated as a service. Ideally you send them the microphone together with the amplifier, because it also has an influence on frequency response.

 

Avoid microphones wich come with generic frequency graphs or files (some of the inexpensive ones like t-bone have them), they are useless. Some compamies sell already calibrated microphones, these are perfect. iSEMcon in Germany is one of them. Buying your own microphone and having it calibrated is still more cost effective.

 

To give you an example why calibration is necessary, take a look at some diagrams. The example is taken from a German periodical (sorry, the text is in German) targeting the DIY speaker community. They also offer microphone calibration as a service and show a summary of the calibrations they did over the last years. You will find some popular brands and their deviations due to manufacturing tolerances.

 

 

As you can see from the various graphs in the link, the biggest deviations from the ideal frequency response occur below 50 Hz and above 10 kHz.

 

Thanks iago, however I'm still confused because here:

Dirac Online Store. UMIK-1 USB Measurement Microphone

 

It says that it is provided with a unique calibration file based on the serial number to ensure accurate measurements.

 

so since the calibration file is based on unique serial number i assume each UMIK-1 is calibrated properly. Or this calibration file is generic?

 

thanks for the explanation.

[iago]

So since the calibration file is based on unique serial number i assume each UMIK-1 is calibrated properly. Or this calibration file is generic?

 

I have no experience with this particular microphone, so this is solely based on information I found on the internet. It is difficult to tell if the calibration file is really obtained by calibration. It is definitely individual, but the wording is ambiguous. I would expect them to state somewhere "we calibrate each microphone before shipping", which they do not. An individual measurement done by Hifi Selbstbau - the same source already quoted above - shows deviations between calibration data and frequency response.

 

 

Pro: Even with an inexact calibration file, the result seems to be within 2 dB of the exact frequency response. The microphone includes amplifier and ADC, there is no additional cost. Con: You only have an exact response for 0° orientation. Conclusion: If you need it for a one-time application, it's not a bad deal. I would still prefer a separate microphone plus individual calibration (about the same price), since I have the electronics around.

[firedog]

My understanding from email correspondence is that the UMIK-1 IS provided with an individually measured calibration file. If you want to be 100% sure, write them and ask them explicitly if the file is uniquely measured for each mic.

 

Alternatively, you can order from here and they individually measure each mic.

 

Thanks iago, however I'm still confused because here:

Dirac Online Store. UMIK-1 USB Measurement Microphone

 

It says that it is provided with a unique calibration file based on the serial number to ensure accurate measurements.

 

 

so since the calibration file is based on unique serial number i assume each UMIK-1 is calibrated properly. Or this calibration file is generic?

 

thanks for the explanation.

[flak]

My understanding from email correspondence is that the UMIK-1 IS provided with an individually measured calibration file. If you want to be 100% sure, write them and ask them explicitly if the file is uniquely measured for each mic.

 

Alternatively, you can order from here and they individually measure each mic.

 

I quote Firedog and I add that I like the option of the UMIK-1 with the CSL calibration because of the availability of the 90° calibration that allows to measure with a vertical orientation of the mic at a limited additional cost of 20 dollars

 

Ciao, Flavio

[Narukama]

I quote Firedog and I add that I like the option of the UMIK-1 with the CSL calibration because of the availability of the 90° calibration that allows to measure with a vertical orientation of the mic at a limited additional cost of 20 dollars

 

Ciao, Flavio

 

I already ordered from miniDSP and since there was no option I guess my UMIK-1 will only be suitable for measuring room only which is what I solemnly intend to do (for now)

This is my 1st mic purchase & obviously it is more complex than I thought. Thanks all.

[Youreye]

Hi Narakuma,

 

you'll be perfectly fine with the UMIK-1! I bought it myself just for the DIRAC Live and the improvement to an receiver "puck" microphone that was giving similar response (peaks and lows) the outcome from a calibrated mic was like night and day!

Don't forget to post your speaker setup and the outcome from the measurement;)

[Narukama]

Hi Youreye,

Thanks for the information. I will set up my system in around 2 months from now. I will post my before/after calibration. Thanks again.

[Kafy]

HI guys,

 

 

I reborn this old thread because I want to buy a mike to use with Dirac Live and I would be very interested with any experiences.

I am planning to buy one of these mike :

UMIK-1

UMIK-1 from crossspectrum

XTZ

 

 

Does any one can give me the good / bad / necessaries to think to help for my choice ?

 

Thanks for your help

[firedog]

You don't need an expensive mic for this purpose. All of those are okay. Get one that has an individual calibration file.

[Fitzcaraldo215]

HI guys,

 

 

I reborn this old thread because I want to buy a mike to use with Dirac Live and I would be very interested with any experiences.

I am planning to buy one of these mike :

UMIK-1

UMIK-1 from crossspectrum

XTZ

 

 

Does any one can give me the good / bad / necessaries to think to help for my choice ?

 

Thanks for your help

 

Go with UMIK-1 from Crossspectrum. I think you will find the custom calibration much better. Not sure at all if the other options include a 90 degree calibration, like Crossspectrum does standard, but that is critical for room calibration work. It is only a few bucks more. The mike needs to point toward the ceiling with direct and reflected sound striking the mike mainly at 90 degrees.

 

Also, find a good mike stand with a boom. You need that to place the mike properly over the listening seats. Not expensive.

[baddog]

I got my UMIK-1 from minidsp.com, it did include the 90 calibration file as well ( you download the calibration files from their website after entering the serial number of the microphone.

[Kafy]

Thank you for your feedback.

Did you have the oportunitie to compare the miniDSP with the crossspectrum version with Dirac Live ?

 

It seems the XTZ is not very famous here. It has an AD converter outside of the mike what seems better for what I know.

In fact I suppose the differences between those three options will be very small but we all here are looking for those small differences :-)

[Melvin]

I purchased the XTZ Microphone Pro a while back for use with Amarra's iRC (Dirac) and have been pretty happy with it. Works great and is nicely packaged with tripod, cables, calibration file, etc. For my needs it was perfect, if not overkill. FWIW I have little experience with mics.

[armani-thomas]

I have both the XTZ and a CrossSpektrum Umik. I think the Dirac filters from the Cs Umik sounds a little better, than with the XTZ. But it's not a huge difference. Both does a great job?

[Kafy]

Hi,

 

Thank all for your feed back.

 

Armani-Thomas, did you test to use the UMIK with the miniDSP configuration file to compare with the CrossSpectrum one ?

[armani-thomas]

Haven't tried that yet. I'll post an update when it's been tested.

[Kafy]

Thank you very very much.

:-)

[kilroy]

You don't need an expensive mic for this purpose. All of those are okay. Get one that has an individual calibration file.

 

I'm also looking into Dirac and am new to microphones. How does one go about using the calibration file? Does Dirac itself recognize and use the file?

[Fitzcaraldo215]

Yes, provided the calibration file is in the proper format. I would go with their UMIK-1 recommendation, or the Crossspectrum calibrated version of same. Use the 90 degree calibration from among the various choices. You provide the file name to Dirac, and that is it.

[kilroy]

Yes, provided the calibration file is in the proper format. I would go with their UMIK-1 recommendation, or the Crossspectrum calibrated version of same. Use the 90 degree calibration from among the various choices. You provide the file name to Dirac, and that is it.

 

Thanks Fitz

[livelistenlearn]

Use the 90 degree calibration from among the various choices. You provide the file name to Dirac, and that is it.

 

btw, for 'stereo' dirac live 'instructs' you to point umik-1 at speakers for 2-channel measurements. iinw, 90º is for multi-channel.

 

recently acquired umik-1 from minidsp, as per flak's recommendation. can confirm login to minidsp site to DL both normal and 90º mic-specific calibrations.

 

cheers.

[armani-thomas]

Hi,

 

Thank all for your feed back.

 

Armani-Thomas, did you test to use the UMIK with the miniDSP configuration file to compare with the CrossSpectrum one ?

 

Hey kafy. I can now confirm there is no audible difference whether I use the standard umik 90 degree calibration file vs the cross spectrum one. In REW I can measure under 1db difference in bass region and about the same in the high treble >10khz. Between 100hz-10khz they look pretty identical.