Measurement mic for home theatre calibration

[AVsion]

Hi All,

I'm new to this forum but been following audioholics for a while, best place to learn about audio, great job guys.

i would like to buy a good quality measurement equipment for our home theatre installation jobs, to be able to properly calibrate the speakers and subwoofers, without the audyssey auto button

The equipment we after will be used in average home theatre consumer installation (with the option measure hi end systems in the future). From the research i've done there are two ways (or more) to go about it , such as USB MIC or Phantom power balanced MIC with interface. i think i prefer going towards Phantom power balanced MIC with interface option ,as for the low noise and other, but happy to go with just USB mic if you think i'm going overboard.

Measurement mic specs
the measurement mic should allow SPL HT reading (without using separate SPL meter) to balance the speakers and subwoofer levels, allow to take room EQ measurements for use with REW software and Smaart (rational acoustics), allow RTA (real time) measurements (with smaart, option to upgrade in the future), allow good frequency range for subwoofers and speakers, comes with calibrated file, work with both OS PC and MAC or suggest any other specification you think i should need for my use.

Budget - up to $500 (less the best)

Interface Spces

The interface should have the option for 2 or more mic inputs (if need?) and enough outputs , OS PC and MAC, or suggest any other specification you think i should need for my use.

Budget - up to $500 (less the best)

The Microphone i looked at are the miniDSP UMIK-1 and the AUDIX TM1 Plus

Can you please let me know what is the best way to go for a USB MIC or Phantom power balanced MIC, what interface you recommend to get? what brand/model? how much should i spend? how many MIC do i need?

FYI we don't have much experience with REW but very serious about it

Appreciate your help

Thank you

 

[lovinthehd]

I'd go with a Umik-1 or the Dayton UMM-6 or maybe the CSL version of either in conjunction with use of REW, or for simplicity just pickup the Omnimic v.2 from parts-express.com

 

[TheWarrior]

Hi All,

I'm new to this forum but been following audioholics for a while, best place to learn about audio, great job guys.

i would like to buy a good quality measurement equipment for our home theatre installation jobs, to be able to properly calibrate the speakers and subwoofers, without the audyssey auto button

The equipment we after will be used in average home theatre consumer installation (with the option measure hi end systems in the future). From the research i've done there are two ways (or more) to go about it , such as USB MIC or Phantom power balanced MIC with interface. i think i prefer going towards Phantom power balanced MIC with interface option ,as for the low noise and other, but happy to go with just USB mic if you think i'm going overboard.

Measurement mic specs
the measurement mic should allow SPL HT reading (without using separate SPL meter) to balance the speakers and subwoofer levels, allow to take room EQ measurements for use with REW software and Smaart (rational acoustics), allow RTA (real time) measurements (with smaart, option to upgrade in the future), allow good frequency range for subwoofers and speakers, comes with calibrated file, work with both OS PC and MAC or suggest any other specification you think i should need for my use.

Budget - up to $500 (less the best)

Interface Spces

The interface should have the option for 2 or more mic inputs (if need?) and enough outputs , OS PC and MAC, or suggest any other specification you think i should need for my use.

Budget - up to $500 (less the best)

The Microphone i looked at are the miniDSP UMIK-1 and the AUDIX TM1 Plus

Can you please let me know what is the best way to go for a USB MIC or Phantom power balanced MIC, what interface you recommend to get? what brand/model? how much should i spend? how many MIC do i need?

FYI we don't have much experience with REW but very serious about it

Appreciate your help

Thank you

Sounds like you have a good head on your shoulders. At best, Audyssey will do nothing. Even as an auto setup rig, it still confuses distances.

Assuming you start with good loudspeakers - Smooth on axis, controlled off axis, sound power, and directivity index (very few manufacturers actually supply this info) - then most of the work needing to be done in small rooms is below the transition frequency, where bass resonates in conjunction with the physical dimensions of the room.

If you are really committed to sound quality, buy 'Sound Reproduction - Loudspeakers and Rooms' by Floyd Toole. For all intents and purposes, it is a text book without a classroom.

Skip to Chapter 13, with perhaps an intro 'course' in Chapter 14 that summarizes the book up to that point. The examples used are for rectangular rooms, but the information can be applied to any room.

That said, $500 would be a waste. Like Lovinthehd said, the UMIK is plenty. Its around $70, and REW is free. The Dayton mic supplies its own software, which I have found to be inadequate.

 

[WaynePflughaupt]

I’d recommend a calibrated UMIK-1 from Cross Spectrum Labs.

The calibration file, when loaded into the measurement platform, essentially gives you a mic with perfectly flat response. Thus a cheaper mic (like the UMIK) can be used instead of, and just as well as, a pricey one (like the AUDIX).

the measurement mic should allow SPL HT reading (without using separate SPL meter)

I know you can do that with a USB mic like the UMIK, but I’m not sure about a mic used with an interface. The USB mics come with a calibration file with a sensitivity line as the first entry, which is necessary for a program like REW calculates dB-SPL. I’m not sure if the calibration file for a phantom-powered measurement mic includes that line. Mine doesn’t seem to, but it’s 10 years old – maybe things have changed since then.

In any event, I’m sure Herb at Cross Spectrum could clarify this for you.

As far as phantom-powered mics and interfaces go, if you choose that route, Cross Spectrum recommends the Dayton EMM-6. It appears that the Premium Plus calibration may have the sensitivity figure you need for SPL, but again Herb can clarify. If it turns out that you can’t get a sensitivity figure in the calibration file for a phantom-powered mic, you’ll need an outboard SPL meter.

For a suitable interface, there are plenty of recommendations on the REW Soundcard Database thread. I’d pay particular attention to the information in Post 102.



Bottom line, you can get into this for way cheaper than your $500 budget.

Regards,
Wayne A. Pflughaupt

 

[AVsion]

I'd go with a Umik-1 or the Dayton UMM-6 or maybe the CSL version of either in conjunction with use of REW, or for simplicity just pickup the Omnimic v.2 from parts-express.com

Thank you for the info will check out those models, sorry for the late reply was on daddy duty this weekend

 

[AVsion]

Sounds like you have a good head on your shoulders. At best, Audyssey will do nothing. Even as an auto setup rig, it still confuses distances.

Assuming you start with good loudspeakers - Smooth on axis, controlled off axis, sound power, and directivity index (very few manufacturers actually supply this info) - then most of the work needing to be done in small rooms is below the transition frequency, where bass resonates in conjunction with the physical dimensions of the room.

If you are really committed to sound quality, buy 'Sound Reproduction - Loudspeakers and Rooms' by Floyd Toole. For all intents and purposes, it is a text book without a classroom.

Skip to Chapter 13, with perhaps an intro 'course' in Chapter 14 that summarizes the book up to that point. The examples used are for rectangular rooms, but the information can be applied to any room.

That said, $500 would be a waste. Like Lovinthehd said, the UMIK is plenty. Its around $70, and REW is free. The Dayton mic supplies its own software, which I have found to be inadequate.

Thanks for your reply,

I agree when setup with audyssey most of the parameters are incorrect especially the crossover, in one of the installation audyssey set a HT satellite speakers down to 40hrz when the specs where way above normally I turn audyssey off and do all the AVR setup manually using laser meter to take distances and SPL meter for balancing the speakers/subwoofer levels to 75dB, speakers all to small, crossover between 80 to 110 dB depending on the speakers. This way I find the sound is clear and natural both for movies and music.

I know Floyd toole didn’t read the book, on my to do list, but watched all his videos on youtube especially “Floyd Toole - Sound reproduction – art and science/opinions and facts” and “Dr. Floyd E. Toole - Get your music listening right” on home theatre geeks with scott wilkinson must watch both.
I personally believe that Floyd way is the way to go, in sound reproduction we should first solve the room issues With good speakers and deal with the low frequency room issues by adding multiple subs. Absorbing the energy with acoustic panels first, is creating a problem, why should you absorb all the energy that the artist created, expensive gear you spend on to reproduce that content and turn it to heat! What is the logic in that. I would use it for sound production or as last option.

I will read about the options you mentions, thank you very much

 

[lovinthehd]

Thanks for your reply,

I agree when setup with audyssey most of the parameters are incorrect especially the crossover, in one of the installation audyssey set a HT satellite speakers down to 40hrz when the specs where way above normally I turn audyssey off and do all the AVR setup manually using laser meter to take distances and SPL meter for balancing the speakers/subwoofer levels to 75dB, speakers all to small, crossover between 80 to 110 dB depending on the speakers. This way I find the sound is clear and natural both for movies and music.

I know Floyd toole didn’t read the book, on my to do list, but watched all his videos on youtube especially “Floyd Toole - Sound reproduction – art and science/opinions and facts” and “Dr. Floyd E. Toole - Get your music listening right” on home theatre geeks with scott wilkinson must watch both.
I personally believe that Floyd way is the way to go, in sound reproduction we should first solve the room issues With good speakers and deal with the low frequency room issues by adding multiple subs. Absorbing the energy with acoustic panels first, is creating a problem, why should you absorb all the energy that the artist created, expensive gear you spend on to reproduce that content and turn it to heat! What is the logic in that. I would use it for sound production or as last option.

I will read about the options you mentions, thank you very much

It's not that they're incorrect, just perhaps not what you expected. The room and speaker response for an f3 point at 40hz is what most avr's (not Audyssey) use....and delay (distance) setting for a sub has to do with more than just physical difference....

 

[lovinthehd]

Thank you for the info will check out those models, sorry for the late reply was on daddy duty this weekend

No problem the CSL I referred to is Cross Spectrum Labs....

 

[AVsion]

Thanks all for your reply,

Look like the UMIK 1 from CSL is the recommended one for using with REW software, i have few questions regarding the UMIK 1

1. I read on CSL FAQ page that CSL calibration file sensitivity data is not included (see below) and on other forums say that the miniDSP version SPL reading are not accurate as a SPL meter. is there a fix for the sensitivity issue yet? as i prefer to have one microphone that will do both SPL reading and EQ measurements

What about microphone sensitivity?
We provide sensitivity values for our EMM-6 Premium+ products which can be directly determined by measuring the voltage output of the microphone for a given SPL input. For USB microphones like the UMIK-1 this process is more complex as we have found that computer hardware, OS settings and program settings can affect the sensitivity value. Therefore we do not provide this information with our calibration files.

If you need the sensitivity value for a given microphone for REW, you can try downloading the MiniDSP factory calibration file and copying the sensitivity line onto the top of our .FRD calibration files.

2. i read on CSL FAQ page that there is some issues (see below) with the clock source, is that will limit me in some way for tuning HT? and what this issue will affect?

What is the down side?
The major issue we have discovered with the UMIK-1:

• The microphone may not work properly with software that expects the input device and output device to share the same clock source (for example, ARTA has issues when averaging multiple measurements with the UMIK-1).

3. is there a big difference between the calibration files from CSL and mini DSP? except of the frequency response ,which is a big tick, as i live in sydney australia and it's much easier to get it from miniDSP in hong kong, but happy to pay the extra money to get the best.

mini DSP Frequency response 20 Hz - 20kHz +/-1dB with calibration loaded
CSL Frequency response 5 Hz - 25kHz +/-1dB with calibration loaded

4. CSL mention he has few calibration files which one should i go for?

Thank you

 

[TheWarrior]

Thanks all for your reply,

Look like the UMIK 1 from CSL is the recommended one for using with REW software, i have few questions regarding the UMIK 1

1. I read on CSL FAQ page that CSL calibration file sensitivity data is not included (see below) and on other forums say that the miniDSP version SPL reading are not accurate as a SPL meter. is there a fix for the sensitivity issue yet? as i prefer to have one microphone that will do both SPL reading and EQ measurements

What about microphone sensitivity?
We provide sensitivity values for our EMM-6 Premium+ products which can be directly determined by measuring the voltage output of the microphone for a given SPL input. For USB microphones like the UMIK-1 this process is more complex as we have found that computer hardware, OS settings and program settings can affect the sensitivity value. Therefore we do not provide this information with our calibration files.

If you need the sensitivity value for a given microphone for REW, you can try downloading the MiniDSP factory calibration file and copying the sensitivity line onto the top of our .FRD calibration files.

2. i read on CSL FAQ page that there is some issues (see below) with the clock source, is that will limit me in some way for tuning HT? and what this issue will affect?

What is the down side?
The major issue we have discovered with the UMIK-1:

• The microphone may not work properly with software that expects the input device and output device to share the same clock source (for example, ARTA has issues when averaging multiple measurements with the UMIK-1).

3. is there a big difference between the calibration files from CSL and mini DSP? except of the frequency response ,which is a big tick, as i live in sydney australia and it's much easier to get it from miniDSP in hong kong, but happy to pay the extra money to get the best.

mini DSP Frequency response 20 Hz - 20kHz +/-1dB with calibration loaded
CSL Frequency response 5 Hz - 25kHz +/-1dB with calibration loaded

4. CSL mention he has few calibration files which one should i go for?

Thank you

Hi, I haven't been on this week...

It is good to have an analog SPL meter just to verify everything. I think some of the phone apps are decent as well.

If you are using REW, you should not have any issues with UMIK. The cal file is downloaded from miniDSP, just have to import to REW. I've never used ARTA, so I can't comment on compatibility issues.

So you're planning to start a home theater set up company?

 

[AVsion]

Hi, I haven't been on this week...

It is good to have an analog SPL meter just to verify everything. I think some of the phone apps are decent as well.

If you are using REW, you should not have any issues with UMIK. The cal file is downloaded from miniDSP, just have to import to REW. I've never used ARTA, so I can't comment on compatibility issues.

So you're planning to start a home theater set up company?

Hi, I placed an order over the weekend with miniDSP hong kong as Herb from CSL is away and all orders are on hold. I got the UMIK 1 and miniDSP 2x4 for tuning multiple subwoofers, hopefully the issues with the sensitivity can be solved.

I have AV installation company in sydney for few years now www.avsion.com.au
our core business is audio visual but also offer installation services for residential and businesses such as Networking /WiFi, home automation, CCTV and telecommunication cabling. i love technology but my passion
was always audio, striving for the best sound. i'm building at the moment my home theatre, the sound processing will be based on AURO 3D 11.2 ,my favorite over Dolby Atmos, for the gear i'm using the Maranz MKII preamp, EMOTIVA XPA5 Gen 3 AMP, focal chorus speakers and SVS Subwoofers. i would like to have my system tuned using REW with UMIK 1 to get the best results possible and also offer this new service to our clients (once i master it).

if you have more information or tips will be great,

thank you for your help.

 

[TheWarrior]

'Sound Reproduction: Loudspeakers and Rooms' is about 530 pages. I couldn't hope to offer you a better source of information. You will find that Floyd's CIRMMT video is like a short 'audio-book' version.

It's complex stuff, but I hope it some day becomes a requirement, especially for manufacturers to adopt the standards proposed by, and developed in conjunction with this book.