Tried your Umik-2 file for a convolution correction with my own Umik-2. Following both your guides. You do some great intricate instructions if you follow along doing the thing as you watch.
The cal files work inversely when loaded to a measurements. Convolving as in AxB multiplication will have the opposite effect. Umik-2 cal files are individual (if you believe MiniDSP) so it's not unexpected that the one for my unit will not be perfect for your unit. If you have questions on the instructions, feel free to ask here.
It's all fun trying out what the difference is. You have some great detailed videos on how to get improved results with Room/Audio correction. You just get more detailed and better with each as you go from your first ones and then watch your latest videos. All useful to a great extent for someone getting started with this.
Just to compare the cal file for your Umik-2 has ~5dB+ difference in the Brilliance range 10kHz+ compared to my own. Gives a large difference there if I use my own calibration or try out your one. Elsewhere you can't really notice much measuring the frequency response of the speakers as a test.
YEs, most of the cal file differences (including 0 deg vs 90 deg) are beyond the frequencies that you would wanna apply filters. Above 1kHz, you should think twice before applying any correction to a speakers' response. @@nighthog7003
Thank you for the guide, I really love it! I am now calibrating really cheap microphones ($6) against UMIK-1. I have found that the responses are off course smoother when measuring very close to the speaker element. Would you advice this or rather measure in the room? When SPL aligning the measurements you get a gain from the offset to the reference microphone that would not be included in the exported calibration file. Isn't it better to calibrate witout doing the SPL alignment first?
Near field measurements would generate smoother responses with less reflections. We try to simulate it by applying octave band smoothing but I think NF is still better. Only USB mics need that gain adjustment. While comparing responses mics volume levels should be eliminated. Best way is to use REW Align SPL tool before creating correction.
I'm a bit doubtful that your unsmoothed DIY cal file will remain valid once you move the microphones even a bit. It just seems contaminated with room acoustics if that makes sense. I'd try to make multiple measurements at different locations in the room, then let REW calculate the difference for each position, overlay them all, and see how similar they are. I suspect that there'll be a general Trendline, but the peaks and dips in the delta above ~1kHz will probably be different for each position.
They all measure the same sweep, noise, distortion simultaneously but room reflections arrive from different angles and distances to the tips of the mics and that's about 2cm difference. Smoothing above 15kHz would make sense. I tried smoothed vs unsmoothed cal files at different locations. Unsmoothed version always gave better results. The downloadable cal files are all smoothed to 1/3 though.
Dirac A.R.T vs trinnov WAVEFORMING vs VBA ? it was supposed to be live by this time but you didn't uploaded it . Any reasons behind it ? eagerly waiting for that video.
Hey OCA, have you tried measuring the system with the zero degree file? I just got a UMIK2, and I'm wondering good the 0 degree would sound vs the 90 degree.
Yeah, I just checked the calibration file. The difference is a lot. I wondering if I can get more accuracy measuring directly at the speaker, Going to try it today.@@ocaudiophile
Hey OCA, have you tested a UMIK2 with the default calibrated file vs the upgraded UMIK2 calibration file? Can you hear a difference after calibration? If I use the file that you've provided will my UMIK2 perform as good as an earthworks MIC? I'm going to test your 90 degree file and see if I can measure and hear a difference.
İ did but Umik-2 mics are individually calibrated (not batch calibration like the Umik-1) and the cal file supplied was pretty accurate. You'd benefit from generating a min phase version of its cal file though if you intend to make accurate phase corrections.
Do you recommend the UMIK2 vs the UMIK1? I heard the UMIK2 had issues when it was first released. I want to buy a 2nd calibration microphone. Do you recommend UMIK2?
Umik-2 has better resolution and accuracy compared to Umik-1 but it all depends on the calibration file at the end. USB interfaces have clocking issues though and for the best phase measurements you need an analogue mic which will also need an audiointerface. The best option is this (used by pros): www.isemcon.net/shopus/product_info.php?products_id=9 A cheaper alternative is this: www.rationalacoustics.com/products/ra-rta-420 As per the audio interface, options are many but here's a reasonably priced one from Motu with very low distortion and digital loopback option: www.amazon.com/MOTU-M2-USB-C-Audio-Interface/dp/B0812B26TN
You need to calibrate volume before taking a measurement with an analogue mic by using REW's SPL meter. REW will normally remind you to do that before taking a measurement? Only USB mics come with their volume alignment data embedded in their mic cal files.
@@ocaudiophile got it, just need to figure out how to do that, it's late here I'll have a look at it tomorrow. Thanks for all your videos and interaction with the comments
Great! This will make the price of the pro version even more attractive. Any requirements for the speakers except for some response in the measurement range?
Not really, although you need to produce a sweep that plays all audible frequencies and for lower bass, your speakers should be adeqaute or have a subwoofer connected to them.@@eventhatsme
i was wondering. arent calibration files just some eqs? that means they could be iir and mess with the phase response, even when you try to flatten it. is that how it works?
True but they are minimum phase filters so the effect to phase is minimal and mic calibration files don't have phase information so it's completely ignored!
@@ocaudiophile your response is yes but no. i think its not needed since the eq is applied internally and no phase adjusments needed. look what i found: The disadvantage of IIR filters is the nonlinear phase response. IIR filters are well suited for applications that require no phase information, for example, for monitoring the signal amplitudes. FIR filters are better suited for applications that require a linear phase response. if this is true this means the phase from the cal file should be extracted and inverted in the final phase response, and that linear phase is calibrated to the phase of the iir filter. is this the case?
You cannot correct phase response with IIR filters, they only work on the frequency magnitude response although they all have some minimal often ignored effect on the phase. All eqaulizers (GEQ or PEQ) are IIR filter types. If you want to correct phase, you need FIR filters which are filters convolved with the speaker's response continiously with multiple taps by a convolution engine. They are much more capable than IIR filters but also require processing power and expensive chipsets (ie a PC) so they are more rare. Now, if you want the best correction, you need to correct also phase response as this adjusts timing differences between different frequencies. A frequency can be made to sound at the correct level by an IIR filter but IIR filter cannot fix if it arrives too early compared to the next frequency. To be able to fix phase, you also need to measure the phase response correctly and for that your measurement microphone's own phase anamolies should be separated from the speaker's response.@@Smecerul08
@@ocaudiophile so even a o diaphragm microphone has phase anomalities? I was thinking more on getting the phase just from the calibration file then calibrate it using all pass filters, or maybe with a combination of iir and fir. Is this possible?
All I can say is just WOW.... Love this channel .. My home theater 7.2.4 Atmos/ Auro system has never sounded so damn good.. Thanks OCA !!!
You're welcome!
Love your content as you know, glad to be here
You need more people who watch your stuff, come on algorithm!
Cheers!
I'm at the very beginning of the journey. Thank you for this beautiful video
You got this!
Another great video, thank you OCA!
My pleasure!
Tried your Umik-2 file for a convolution correction with my own Umik-2.
Following both your guides.
You do some great intricate instructions if you follow along doing the thing as you watch.
The cal files work inversely when loaded to a measurements. Convolving as in AxB multiplication will have the opposite effect. Umik-2 cal files are individual (if you believe MiniDSP) so it's not unexpected that the one for my unit will not be perfect for your unit. If you have questions on the instructions, feel free to ask here.
It's all fun trying out what the difference is.
You have some great detailed videos on how to get improved results with Room/Audio correction. You just get more detailed and better with each as you go from your first ones and then watch your latest videos.
All useful to a great extent for someone getting started with this.
Thank you. I'm only sharing information I gather in the search for perfect sound ;)@@nighthog7003
Just to compare the cal file for your Umik-2 has ~5dB+ difference in the Brilliance range 10kHz+ compared to my own. Gives a large difference there if I use my own calibration or try out your one. Elsewhere you can't really notice much measuring the frequency response of the speakers as a test.
YEs, most of the cal file differences (including 0 deg vs 90 deg) are beyond the frequencies that you would wanna apply filters. Above 1kHz, you should think twice before applying any correction to a speakers' response. @@nighthog7003
This is insane.
Thank you for the guide, I really love it! I am now calibrating really cheap microphones ($6) against UMIK-1. I have found that the responses are off course smoother when measuring very close to the speaker element. Would you advice this or rather measure in the room? When SPL aligning the measurements you get a gain from the offset to the reference microphone that would not be included in the exported calibration file. Isn't it better to calibrate witout doing the SPL alignment first?
Near field measurements would generate smoother responses with less reflections. We try to simulate it by applying octave band smoothing but I think NF is still better.
Only USB mics need that gain adjustment. While comparing responses mics volume levels should be eliminated. Best way is to use REW Align SPL tool before creating correction.
I'm a bit doubtful that your unsmoothed DIY cal file will remain valid once you move the microphones even a bit. It just seems contaminated with room acoustics if that makes sense.
I'd try to make multiple measurements at different locations in the room, then let REW calculate the difference for each position, overlay them all, and see how similar they are. I suspect that there'll be a general Trendline, but the peaks and dips in the delta above ~1kHz will probably be different for each position.
They all measure the same sweep, noise, distortion simultaneously but room reflections arrive from different angles and distances to the tips of the mics and that's about 2cm difference. Smoothing above 15kHz would make sense. I tried smoothed vs unsmoothed cal files at different locations. Unsmoothed version always gave better results. The downloadable cal files are all smoothed to 1/3 though.
Dirac A.R.T vs trinnov WAVEFORMING vs VBA ? it was supposed to be live by this time but you didn't uploaded it . Any reasons behind it ? eagerly waiting for that video.
I've got surprize visitors, hopefully be posted by the weekend
Hey OCA, have you tried measuring the system with the zero degree file? I just got a UMIK2, and I'm wondering good the 0 degree would sound vs the 90 degree.
The difference will be only in the high frequencies...
Yeah, I just checked the calibration file. The difference is a lot. I wondering if I can get more accuracy measuring directly at the speaker, Going to try it today.@@ocaudiophile
Hey OCA, have you tested a UMIK2 with the default calibrated file vs the upgraded UMIK2 calibration file? Can you hear a difference after calibration? If I use the file that you've provided will my UMIK2 perform as good as an earthworks MIC? I'm going to test your 90 degree file and see if I can measure and hear a difference.
İ did but Umik-2 mics are individually calibrated (not batch calibration like the Umik-1) and the cal file supplied was pretty accurate. You'd benefit from generating a min phase version of its cal file though if you intend to make accurate phase corrections.
okay, I'll try that instead. Thanks.@@ocaudiophile
Thanks OCA.@@ocaudiophile
Do you recommend the UMIK2 vs the UMIK1? I heard the UMIK2 had issues when it was first released. I want to buy a 2nd calibration microphone. Do you recommend UMIK2?
Umik-2 has better resolution and accuracy compared to Umik-1 but it all depends on the calibration file at the end. USB interfaces have clocking issues though and for the best phase measurements you need an analogue mic which will also need an audiointerface. The best option is this (used by pros):
www.isemcon.net/shopus/product_info.php?products_id=9
A cheaper alternative is this:
www.rationalacoustics.com/products/ra-rta-420
As per the audio interface, options are many but here's a reasonably priced one from Motu with very low distortion and digital loopback option:
www.amazon.com/MOTU-M2-USB-C-Audio-Interface/dp/B0812B26TN
@@ocaudiophile I ordered a umik2 😀.
Definetely the most accurate of easy to set up mics!
@@ocaudiophile thanks OCA 👍.
Nice, should be getting it in a couple of days. @@ocaudiophile
Hocam dosyalar mevcut değil tekrar upload yapabilirmisiniz?
It's all there brov!
Thank you very much, interestingly, I was able to see the file when I looked through VPN.@@ocaudiophile
out of courisity i downloaded your ayd mic cal file and took a measurement against my umm6, the ayd mic is 20db higher....am i doing something wrong?
You need to calibrate volume before taking a measurement with an analogue mic by using REW's SPL meter. REW will normally remind you to do that before taking a measurement? Only USB mics come with their volume alignment data embedded in their mic cal files.
@@ocaudiophile got it, just need to figure out how to do that, it's late here I'll have a look at it tomorrow. Thanks for all your videos and interaction with the comments
@@ocaudiophile I've got the umm6, will be an issue if I use it at 90 degree even though it doesn't come with a 90 degree calibration file?
You will have a correct response only until 10-12kHz which is usually more than enough for creating filters.@@andrew1977au
Can this technique be used for 90 degrees mic orientation as well?
Yes, I tried it myself after the video and shared the cal files produced in the decsription link.
Great! This will make the price of the pro version even more attractive. Any requirements for the speakers except for some response in the measurement range?
Not really, although you need to produce a sweep that plays all audible frequencies and for lower bass, your speakers should be adeqaute or have a subwoofer connected to them.@@eventhatsme
i was wondering. arent calibration files just some eqs?
that means they could be iir and mess with the phase response, even when you try to flatten it. is that how it works?
True but they are minimum phase filters so the effect to phase is minimal and mic calibration files don't have phase information so it's completely ignored!
@@ocaudiophile your response is yes but no. i think its not needed since the eq is applied internally and no phase adjusments needed. look what i found:
The disadvantage of IIR filters is the nonlinear phase response. IIR filters are well suited for applications that require no phase information, for example, for monitoring the signal amplitudes. FIR filters are better suited for applications that require a linear phase response.
if this is true this means the phase from the cal file should be extracted and inverted in the final phase response, and that linear phase is calibrated to the phase of the iir filter. is this the case?
its cool thet m23r doesnt even need the calibration file
You cannot correct phase response with IIR filters, they only work on the frequency magnitude response although they all have some minimal often ignored effect on the phase. All eqaulizers (GEQ or PEQ) are IIR filter types. If you want to correct phase, you need FIR filters which are filters convolved with the speaker's response continiously with multiple taps by a convolution engine. They are much more capable than IIR filters but also require processing power and expensive chipsets (ie a PC) so they are more rare. Now, if you want the best correction, you need to correct also phase response as this adjusts timing differences between different frequencies. A frequency can be made to sound at the correct level by an IIR filter but IIR filter cannot fix if it arrives too early compared to the next frequency. To be able to fix phase, you also need to measure the phase response correctly and for that your measurement microphone's own phase anamolies should be separated from the speaker's response.@@Smecerul08
@@ocaudiophile so even a o diaphragm microphone has phase anomalities? I was thinking more on getting the phase just from the calibration file then calibrate it using all pass filters, or maybe with a combination of iir and fir. Is this possible?