Measurement Method for Bass Reflex Subwoofer

[Aucosticraft]

Hello Friends,

I have designed a Sub Woofer with satellite speakers ( 5.1) but now I am not sure where to place mic for measurements. I have seen few links which has given methods for 2 way or 3 way systems. but I am confused that if the port is on other side of driver then where to place mic ? Also if you could help me with method for measuring response of whole system.

Regards
Aucosticraft

[transphere]

One way to do it would be to make nearfield measurements of both the driver and the port, and sum these.

Another option (if you have the space) is to make proper far field measurements. But keep in mind that you need a radius of 17 meters around your sub free of reflecting objects to measure accurately down to 20 Hz.

[chris661]

I suppose you could put the mic above the box, so the port and driver have summed by the time the sound hits the mic.

[Aucosticraft]

Dear transphere & Chriss661 thanks for your efforts to answer.

transsphere, I guess your suggestion of nearfield measurement seems practical for me. will try it. I think I can use TrueRTA for this. Please suggest if there is any other tool good and be tried out. TrueRTA has memory facility where u can save and add them later.

Chris661, its a good idea but, it would be hard to find a precise point where driver and port gets equally added. More over the measurement might be angular response. What do you say?