What equipment do you recommend for accurate measurements of frequency response?

[vintologi]

The main problem with mics like the earthworks M23 is that they require mic preamp with phantom power but i am not sure if there are even any particularly good option for that and that could mess up the calibration since that will impact the frequency response as well.

Grace M101 Microphone Preamp Review

This is a review and detailed measurements of the Grace Design M101 single channel microphone preamp. It is on kind loan from a member and costs US $833. OK, this is not a design that I would fall in love with but in the context of studio gear, it will get a pass. I really like the gain...

www.audiosciencereview.com

Ribbon button per documentation gives you a DC path with no phantom power.

There is of course the cheaper umik-1 and umik-2 but neither seem reliable enough for more serious speaker design work.

Then i also need to find a good amplifiers for my speakers (never found any particularly good option).

I guess my old asus xonar STX still works as DAC+ADC.

 

[john61ct]

If you really want accuracy in the phase / time domain, you want to have your input and output clocked by the same DA/AD converter / interface. Or separate ones in sync via BNC Word Clock. Clocking via the signal is OK but not as good.

Bottom line, hardware loopback is much better for accuracy than acoustic reference.

UMIK-2 is much better in this domain than UMIK-1 but all USB based mic's have that basic flaw.

So, XLR. Which means mic preamp(s) and yes 48V PP.

But an inexpensive mixer can provide that, or they are sold standalone, does not need to be built into the converter / interface.

Preamp for a single XLR measurement mic

I plan to use an Echo Audiofire 12 for REW and other measurement / filter design tools. It is I/O only, includes neither HPamp nor mic preamps. I have UMIK-2 but have decided to also get a calibrated XLR mic in order for both the signal output and the measurement precisely clock-sync'd by the...

www.audiosciencereview.com

 

[vintologi]

If you really want accuracy in the phase / time domain, you want to have your input and output clocked by the same DA/AD converter / interface. Or separate ones in sync via BNC Word Clock. Clocking via the signal is OK but not as good.

Bottom line, hardware loopback is much better for accuracy than acoustic reference.

UMIK-2 is much better in this domain than UMIK-1 but all USB based mic's have that basic flaw.

Yes i do need the phase measurement to be accurate as well.

 

[john61ct]

I picked up E-MU 0404 USB 2.0

for $36 delivered on eBay

preamp included for your Earthworks M23

if you already bought that

but TBH IMO overkill pricey unless for a profitable business use case

Read that thread, also good discussion in the Acourate thread, search on mic

 

[john61ct]

ASR Acourate users

So bass management is the function category for all that. With "phase / delay issues" mostly a part of that as opposed to "Custom designing speakers from separately driven drivers" ? aka "bi- or tri-amping" which I expressed not a current goal for me. So, add speaker / room compensation EQ...

www.audiosciencereview.com

What continent are you on?

Cross Spectrum Labs has a great rep

Sonarworks SoundID Reference thread +mic

Shopping for a REW measurement mic individually calibrated for multiple angles https://www.audiosciencereview.com/forum/index.php?threads/asr-acourate-users.47057/post-2541445 Came across Sonarworks' "SoundID Reference mic" at Sweetwater $89 and when I called in they took confirmed its...

www.audiosciencereview.com

 

[vintologi]

What continent are you on?

I live in the EU.

Cross Spectrum Labs has a great rep

Sonarworks SoundID Reference thread +mic

Shopping for a REW measurement mic individually calibrated for multiple angles https://www.audiosciencereview.com/forum/index.php?threads/asr-acourate-users.47057/post-2541445 Came across Sonarworks' "SoundID Reference mic" at Sweetwater $89 and when I called in they took confirmed its...

www.audiosciencereview.com

Ill check it out.

Let's see if i find something better than Grace M101 + Earthworks M23 gen2.

 

[Keith_W]

For serious professional work, you are much better off with an XLR mic + a good mic preamp. The reason: loopback measurements. More expensive XLR mics usually have better sensitivity and wider bandwidth, but I am not sure if any of their other advantages are of practical benefit for most of us.

For hobbyists, any mic will do provided it's an omnidirectional condenser mic with a "small" capsule (i.e. smaller than the shortest wavelength you wish to measure) AND comes with a calibration file. Or you could send it for professional calibration. 20kHz has a wavelength of 17.2mm, so a 1/4" (6.35mm) mic will do the job easily. Any smaller than that, and you run into problems with poor sensitivity. Anything equal to or larger than 17.2mm, and you start running into problems with diffraction around the mic capsule itself.

But - by far the biggest variable is the user. It can be very difficult to take an accurate measurement, depending on what you want the measurement for, how low you want to measure, etc.

 

[john61ct]

My impression when looking is the EU has more / better options.

Messtechnik Pack MM-1C – HiFi-Selbstbau-Der Shop

You can of course spend a lot more money, but IMO does not actually get much more value

 

[vintologi]

My impression when looking is the EU has more / better options.

Messtechnik Pack MM-1C – HiFi-Selbstbau-Der Shop

You can of course spend a lot more money, but IMO does not actually get much more value

I need to have reliable frequency response data both for the mic and the pre-amp.

 

[SSS]

I need to have reliable frequency response data both for the mic and the pre-amp.

They offer the option to calibrate the mic individually.

 

[SSS]

I picked up E-MU 0404 USB 2.0

for $36 delivered on eBay

preamp included for your Earthworks M23

if you already bought that

but TBH IMO overkill pricey unless for a profitable business use case

Read that thread, also good discussion in the Acourate thread, search on mic

Until I purchased the Quantasylum QA403 measurement box I used the E-MU 0404 and the E-MU Tracker pre. These units have good performance and work up to 90 kHz which is more than other mic ADC products. Low distortion, good for measurments. Lack of calibrated in- and output brought me to invest into the QA403 which is a real pretty good measurement system which I use much for amplifier repair and tune up.

 

[vintologi]

I do think it's better to have flat frequency response (and no phase shift) than to have uneven frequency response and then have to rely on calibration (which may not even remain accurate).

Earthworks M23 gen2 does seem decent but not more and also requires phantom power. I assume phantom power doesn't work with DC coupling making it not ideal for testing at very low frequencies (such as 0.2 hz).

Someone on reddit mentioned APx1701 which you can also use to power the speakers it seems but you have to contact them to get price info (i assume the price is very high like 10K $).