Transmit sweep Signal from REW

[caseopia]

Hi John need a help here.

Normally we used a 3,5mm to rca cable for transmit sweep signal from REW to any DSP for car audio measurement.

Question is if the DSP only provide high level (18 pin socket) to original car audio head unit (which no AUX input).

How to transmit REW sweep signal to original car head unit?So we can get impulse measurement and phase result.

 

[JStewart]

Hi John need a help here.

Normally we used a 3,5mm to rca cable for transmit sweep signal from REW to any DSP for car audio measurement.

Question is if the DSP only provide high level (18 pin socket) to original car audio head unit (which no AUX input).

How to transmit REW sweep signal to original car head unit?So we can get impulse measurement and phase result.

You will need to measure using a playback file generated in REW. Start on this page, scroll to “measuring with file playback”. Follow the links in the section for additional how to.

Making Measurements

 

[caseopia]

You will need to measure using a playback file generated in REW. Start on this page, scroll to “measuring with file playback”. Follow the links in the section for additional how to.

Making Measurements

Oh i get it it's called offline measurement?

Problem that i don't get it is how to record the file from my system?Using a recorder from my android phone or what

 

[ddude003]

Use the REW Generator function to create a .wav file... You would end up with a .wav file containing a sweep with a timing reference that can be transferred to a CD or USB jump drive that you play thru your signal chain (read audio head unit)... Or even transfer the .wav sweep file to your phone if you use that as your playback device for your signal chain... Use a separate laptop with a usb mic running REW to capture the measurement...

 

[John Mulcahy]

Measuring with file playback.

 

[caseopia]

Use the REW Generator function to create a .wav file... You would end up with a .wav file containing a sweep with a timing reference that can be transferred to a CD or USB jump drive that you play thru your signal chain (read audio head unit)... Or even transfer the .wav sweep file to your phone if you use that as your playback device for your signal chain... Use a separate laptop with a usb mic running REW to capture the measurement...

View attachment 71886

Thank you sir for your guidance. My brain cannot catch after i play with head unit.

I mean how to capture measurement on other laptop using REW and umik-1?
Use record on RTA or how?

Thank you beforehand

 

[John Mulcahy]

You just make a measurement like normal, with the playback set to "From file", exactly as it shows in the help.

 

[caseopia]

You just make a measurement like normal, with the playback set to "From file", exactly as it shows in the help.

Then no different since i cannot get the impulse result from my speakers because i cannot connect any cable to the car player (head unit) with no aux input

 

[John Mulcahy]

Please read the help I have now linked twice. There is no connection to the unit, the unit plays back a file.

 

[caseopia]

Please read the help I have now linked twice. There is no connection to the unit, the unit plays back a file.

Yes John been read it plenty of times and still don't get it the part after i play on my head unit.

How to capture the sound with REW on other laptop?

And how i get value (timing ref trim) to fill in the red box i attach?

 

[John Mulcahy]

You don't need to change the timing ref trim, leave it at zero. It is just like making a normal measurement except after pressing start on the measurement when REW shows "waiting for timing reference" you play the file. It is NOT offline measurement.

 

[caseopia]

You don't need to change the timing ref trim, leave it at zero. It is just like making a normal measurement except after pressing start on the measurement when REW shows "waiting for timing reference" you play the file. It is NOT offline measurement.

Ok let me type one by one and please correct me if my understanding are wrongs:

1. open REW and connect the UMIK-1 as usual
2. click generator icon on top right of the REW screen then choose sweeps box + measurement box under it
3. click save to file on bottom of the screen and click WAV right under the screen.
4. move that file to any data container (i choose USB flashdrive) and play it on my car head unit
5. on my other laptop that connected to UMIK-1 open REW and click measure
6. change the timing to wired timing reference and playback option to from file
7. then i will get the result.

Is that it John?

 

[John Mulcahy]

Not quite, no. You do not have a wired connection so you don't use a wired timing reference. Just follow the steps in the help: https://www.roomeqwizard.com/help/help_en-GB/html/makingmeasurements.html#fileplayback