Calibration Microphone

[alin_im]

Hi all,

I am new to room acoustics and I want to start dabbling with it. I am a network engineer which is passionte about DIY and AV. I am not an audio producer so am I only listening to it.

I am in the market for a room calibration microphone with calibration file, but I am not sure if the price difference between the different models is worth it, so please let me know what you think.

My main object is to play with REW software and try to acoustic treat my rooms. I am not considering USB calibration microphones, I preffer the XLR ones.

I am currently looking at the following 3 models:

• SonarID reference Mic (80 EUR mic only or 190 EUR including Speakers & Headphones software - special price)
• Dayton EMM-6 (80 EUR)
• Beyerdynamic MM 1 (230 EUR)

The 230EUR price tag is the absolute maximum price budget I want to allocate for the mic. The question is it worth getting it for hobby use / family and friends uses ? (worth mentioning in the grand scheme of AV the price difference between the cheaper models and this one might be overlooked if the performance is worth it). I want to get something good and reliable and not stress about it in 5 years time if I will move houses, something that lasts a liftetime.

Also, is Dayton better then SonarID? to my untrained eye in this field, they are identical, apologies for my ignorance, but between the two I might go with the SonarID and software.

Also, is SonarID software worth it for untreated rooms? I know DSP is used as the last tweark after the room is treated. I am not sure if I need this software at this point, please correct me if I am wrong.

One last thing, please let me know if you have any good resources for acoutic tutorials.

My setup:
Office Room:

• PC
• SSL2+ Audio Interface
• Adam A3X Speakers and Adam Sub 8
• ATH M50x Headphones
• Shure SM7B mic

Livingroom Room:

• Cambridge Audio CXA81 amp
• Kef LS50 Meta speakers
• Kef KC62 sub
• Bluesound Node network streamer

EDIT: After further research and your inputs, I decided to go with miniDSP UMIK-1. Thank you all!

 

[Blumlein 88]

The Dayton should be fine for your needs.

 

[DVDdoug]

USB measurement mics have a (potential) advantage in-that they are calibrated for SPL And of course, they are more convenient. With an analog mic the digital signal depends on preamp gain so if you want SPL as well as frequency response they have to be manually calibrated with an SPL meter every time they are set up. Or you can measure SPL separately with an SPL meter.

 

[Keith_W]

The Dayton or SonarID will be fine for your needs. Make sure you buy one that comes with a calibration file. You will also need a mic boom stand like this one.

More expensive mics have greater sensitivity, wider frequency range, and "better design". By this I mean that the capsule is smaller. Normally a smaller capsule means poorer sensitivity, but you WANT a small capsule because the microphone itself can interfere with the measurement if it is too large. I have an Earthworks M30 and two Behringer ECM8000's. The Earthworks is about 10dB more sensitive. It doesn't really matter because I can turn the gain on the mic preamp up, then it's the same.

Re: SonarID (or any DSP) for untreated rooms. Bear in mind that room treatment and DSP address different issues. DSP is less effective for addressing high frequency problems. For that, you want room treatment if you have issues. But room treatment is less effective for low frequency problems, because they need to be so large that it becomes intrusive. DSP is the tool of choice. Toole said that most listening rooms do not need room treatment. Furniture, carpet, curtains, etc. is usually enough to reach the target.

Re: resources for acoustics. I recommend two books: Toole or Everest. I have both. Toole is the better general purpose book for hobbyists. Everest is better for industry professionals. It is possible to learn all you need to know for free from reading dozens of threads on ASR (after all, Toole is extensively discussed and referenced here) but it is better to just get the book.

My personal opinion: everybody on ASR should own a microphone and a copy of Toole. Get your microphone first and do some measurements. Then read Toole and decide what you need to do. ONLY THEN should you consider room treatment and/or DSP.

 

[alin_im]

The Dayton or SonarID will be fine for your needs. Make sure you buy one that comes with a calibration file. You will also need a mic boom stand like this one.

More expensive mics have greater sensitivity, wider frequency range, and "better design". By this I mean that the capsule is smaller. Normally a smaller capsule means poorer sensitivity, but you WANT a small capsule because the microphone itself can interfere with the measurement if it is too large. I have an Earthworks M30 and two Behringer ECM8000's. The Earthworks is about 10dB more sensitive. It doesn't really matter because I can turn the gain on the mic preamp up, then it's the same.

Re: SonarID (or any DSP) for untreated rooms. Bear in mind that room treatment and DSP address different issues. DSP is less effective for addressing high frequency problems. For that, you want room treatment if you have issues. But room treatment is less effective for low frequency problems, because they need to be so large that it becomes intrusive. DSP is the tool of choice. Toole said that most listening rooms do not need room treatment. Furniture, carpet, curtains, etc. is usually enough to reach the target.

Re: resources for acoustics. I recommend two books: Toole or Everest. I have both. Toole is the better general purpose book for hobbyists. Everest is better for industry professionals. It is possible to learn all you need to know for free from reading dozens of threads on ASR (after all, Toole is extensively discussed and referenced here) but it is better to just get the book.

My personal opinion: everybody on ASR should own a microphone and a copy of Toole. Get your microphone first and do some measurements. Then read Toole and decide what you need to do. ONLY THEN should you consider room treatment and/or DSP.

Thank you for the detailed reply!

I will have a look at the recommended books.

So the what what you are saying is that for my use case, an expensive mic like MM1 is not worth the expense and as long as I purchase one with calibration files, like the sonarID, I should be ok.

 

[MAB]

Thank you for the detailed reply!

I will have a look at the recommended books.

So the what what you are saying is that for my use case, an expensive mic like MM1 is not worth the expense and as long as I purchase one with calibration files, like the sonarID, I should be ok.

In case it helps, here are on-axis calibration curves for UMIK-1 and UMIK-2:

These are fairly normal values for a measurement mic's calibration. For example, even the UMIK-2 is going to measure a +1dB emphasized response around 4kHz, and >2dB shelved treble above 7kHz.

I have an Earthworks mic as well. It has incredible bandwidth, and is able to measure noise from the LED lights, plus some audio signals of interest . You will be fine for most room and speaker measurements with a simple USB measurement mic + calibration file.

 

[Keith_W]

If you want to learn more than you ever needed to know about measurement microphones, take a look at Bruel & Kjaer's website and this article. Although B&K talks about difference in design between free field and pressure field microphones, in reality you don't need to buy different mics for each application. One mic with free field calibration is sufficient.

Another difference between cheap and expensive microphones that I forgot to mention is that they may have a different polar response. Omnidirectional microphones are not truly omni. They have a polar response that looks like this:

What this means is that mic orientation matters. As long as you point the mic at whatever you are measuring, or have a calibration file for that orientation of mic, you will be OK.

As you can see, there are differences between cheap and expensive mics. The differences are: wider frequency range, greater sensitivity, better polar response, build quality, availability of calibration, and product support. None of these will get in the way of typical in-room measurements of the type you are planning to do. The MINIMUM mic you should buy should be an omnidirectional condenser type and have a calibration file. If not, then send the mic in for calibration.

 

[AnalogSteph]

As you can see, there are differences between cheap and expensive mics. The differences are: wider frequency range, greater sensitivity, better polar response, build quality, availability of calibration, and product support.

Not to forget noise level and distortion. I have resorted to using a regular LDC mic for speaker measurements because my old measurement mic was lousy in both regards.

 

[Blumlein 88]

Not to forget noise level and distortion. I have resorted to using a regular LDC mic for speaker measurements because my old measurement mic was lousy in both regards.

Which LDC are you using? I've measured distortion on a few SDC's and it is quite variable. Definitely high on old Audio Technica AT 4033 mics. Some cheap CK-1 Avantones are not bad at all.

 

[alin_im]

In case it helps, here are on-axis calibration curves for UMIK-1 and UMIK-2:
View attachment 398890
These are fairly normal values for a measurement mic's calibration. For example, even the UMIK-2 is going to measure a +1dB emphasized response around 4kHz, and >2dB shelved treble above 7kHz.

I have an Earthworks mic as well. It has incredible bandwidth, and is able to measure noise from the LED lights, plus some audio signals of interest . You will be fine for most room and speaker measurements with a simple USB measurement mic + calibration file.

Thank you for the info. I have seen a lot of people are choosing the UMIK-1.

TBH my initial thought was not going with a USB microphone because they might be lacking quality and wanted a more old school reputable brand (not that soundID is one compared to Beyerdynamic). Now, reading more about UMIK-1 and seeing it used by people on YouTube, I am thinking about it for the simplicity and portability of the setup.

I might be overthinking this too much for my needs, but I don't want to spend money and time twice.

 

[MAB]

Thank you for the info. I have seen a lot of people are choosing the UMIK-1.

TBH my initial thought was not going with a USB microphone because they might be lacking quality and wanted a more old school reputable brand (not that soundID is one compared to Beyerdynamic). Now, reading more about UMIK-1 and seeing it used by people on YouTube, I am thinking about it for the simplicity and portability of the setup.

I might be overthinking this too much for my needs, but I don't want to spend money and time twice.

UMIK-1 is great for your purpose.

 

[Keith_W]

DO NOT BUY A UMIK OR ANY USB MICROPHONE if you want to avoid spending money twice! If you desire anything more than simple room or speaker measurements and want to use software packages like Audiolense or Acourate, you will have to buy an XLR microphone.

This video gives you a few other reasons why you should get an XLR microphone.

USB mics have their place. They are cheaper and more portable.

 

[alin_im]

DO NOT BUY A UMIK OR ANY USB MICROPHONE if you want to avoid spending money twice! If you desire anything more than simple room or speaker measurements and want to use software packages like Audiolense or Acourate, you will have to buy an XLR microphone.

This video gives you a few other reasons why you should get an XLR microphone.

USB mics have their place. They are cheaper and more portable.

I will have a play with UMIK when it comes and see if this satisfies my requirements. As you said, I need for simple room measurements. Nothing too advanced TBH. Worst case I will just return it within 14 days and get an XLR one.

 

[oversky]

From REW HELP pdf.

 

[dfiler]

Good call, start with the simplicity of the USB mic. It will be a long time before the UMIK is your limiting factor, if ever. Knowledge and calibration experience are far more important than fidelity beyond this mic.

My take is that the hassle of calibration causes most people to avoid recalibration and the iterative experimentation that is necessary to truly optimally EQ a room. This includes myself. I bought a new couch with a much lower back than the old one. And yet I haven't re-run Dirac and new sweeps. That couch makes a bigger difference than usb vs xlr. So my opinion is that your system will sound the best by doing whatever it takes to keep up to date on calibration. Make that process as simple as possible.

 

[alin_im]

So many opinions I made the decision to chat with audio dealer and they will send both a UMIK1 and a Dayton. Will test both and return one.

 

[AnalogSteph]

Which LDC are you using? I've measured distortion on a few SDC's and it is quite variable.

I think that was just my regular t.bone SC400 at the time (about the cheapest "real" condenser LDC you can buy around here, and arguably not the worst). In more recent times I also had some fun indirectly calibrating my old Samson CL8 which while a tad noisy by LDC standards has an omni mode.... not perfect but OK-ish.

 

[Blumlein 88]

DO NOT BUY A UMIK OR ANY USB MICROPHONE if you want to avoid spending money twice! If you desire anything more than simple room or speaker measurements and want to use software packages like Audiolense or Acourate, you will have to buy an XLR microphone.

This video gives you a few other reasons why you should get an XLR microphone.

USB mics have their place. They are cheaper and more portable.

Stupid video.

 

[Keith_W]

Stupid video.

What do you disagree with?

 

[SSS]

Microphone buying decision should be made based on the target application. If it is a hobby occasional usage without extreme need for accuracy then all the relatively low priced will work well. If precision is mandatory then only a professional mic (high price) will work with repeatable accuracy. For exact measuring SPL a calibrated sound source is needed as well to check the microphones responsiness. Myself I use a professional USB mic with calibration file and I have a set of different Bruel&Kjaer microphones where one is able to go up to 50 kHz. This for listening to bats for instance. And I use a calibrated sound source just to check the mics.