Car audio time delay measurement

[Audiostatus]

Hello to everyone for the first time.


So i been struggling with this problem.
I need an quick and easy way to measure phase difference between a car audio system speakers, or in simple words time align them.

Usually its a 2 way + subwooferor a 3 way + subwoofer.

I have an UMIK-1 or even multiple of them.
And a regular MIC (behringer ECM800) with EMU 0404

As i have tried the best way to measure was with the EMU 0404 with a loopback as a timing reference but i never got correct measurement, or to be precise good results.
Can some help to put an end for this topic ?

 

[Sonnie]

Have you read Jerry Austin's guide? https://www.dropbox.com/s/w7jmpozner6muzw/MiniDSP 2x4 Set-Up Guide Latest Version.pdf?dl=0

It might be helpful... skip on down to where he uses the impulse response overlays to compare timing.

I have been using the acoustical timing reference to check phase between subwoofers.

What processor are you using to set your timing? Does it not convert inches to ms? You could measure manually.

Are you running a sweep thru each channel? You want each speaker to have it's own sweep for time alignment. Don't combine them with any other speaker if at all possible... unless the speakers are co-located together. If you have one in the door and one in the dash... you need to separate the signal somehow if you are not using active crossovers. Keep you sub separate. You can go back and measurement the full set for corrections in response after you get each speakers timing set, but they need to be separated for the timing. For example... I have 7 speakers all with active crossovers... and each gets a tone for alignment. Then I route my sweep thru the entire left channel (including the sub) and then right channel (including the sub) to determine PEQ filters before running my Dirac Live for final corrections.

Of course a miniDSP C-DSP 8x12 DL would solve all your issues.

 

[Audiostatus]

Im using a similar DSP as a MiniDSP. I know that the 8x12 is an option, but its quite expensive for that build.

There is no problem to run sweeps to a separate channel, and i have done that.
And measuring by distance, or even ms is not a problem, i have done that for many years with great results, but when you have all the equipment needed you have to use it right. Also results should be better.

I will read the article.
I think in my case the setup or REW is a problem. Downt know how to setup it right

 

[John Mulcahy]

A loopback with an analog mic should work fine, or a UMIK with an acoustic reference, but in a car loopback should be more reliable. Make sure all your measurements cover the full frequency range for consistent timing of the loopback reference. You would typically need to offset all the results (by the same amount) to account for time of flight delays, that timing offset can be entered on the Measure dialog - or REW can estimate it from your first measurement and enter it for you using the Estimate IR delay feature, it would then automatically be applied for all subsequent measurements (the 5.20 beta version is needed for those features).

 

[Audiostatus]

Well i thought the same.
Also, i cant do a full sweep an o tweeter to cover full frequency range. Also the same goes to woofers and subwoofers.