My new subwoofer build has been designed for an extremely low QTC and so far I like it. TO be honest, I wish I can get even more tighter and controlled but this isn't bad.
Anyway, for a .45 QTC you could imagine the roll off is really steep and no where near flat but when measuring nearfield I get a pretty flat frequency response. Of course when measuring from listening position I get all weird anomalies.
I measured from about 5cm away from the centre of the cone. I chose the sub(have dual subs) which had no side walls.
Have I done something wrong or can room gain really bring up the lower frequencies? This is what I planned but it seems to good to be true...
Or any other theories to this?
Anyway, for a .45 QTC you could imagine the roll off is really steep and no where near flat but when measuring nearfield I get a pretty flat frequency response. Of course when measuring from listening position I get all weird anomalies.
I measured from about 5cm away from the centre of the cone. I chose the sub(have dual subs) which had no side walls.
Have I done something wrong or can room gain really bring up the lower frequencies? This is what I planned but it seems to good to be true...
Or any other theories to this?
Phase Response in Active Filters Part 2, the Low-Pass and High-Pass Response | Analog Devices
Q does not affect the roll off slope, it only affects the transition between rolling off and passing. A low Q means a slow transition transition.
Q does not affect the roll off slope, it only affects the transition between rolling off and passing. A low Q means a slow transition transition.
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What are you exactly suggesting? And how does it connect to me getting a flat frequency response. If you provide me with a conclusion I am sure I can put two and two together....
@ Trdat
First of all any loudspeaker system is a bandpass system, made up of a high pass and a low pass. The diagram shows the high pass part. The speaker shows a certain high pass characterisitc depending on chassis and enclosure, resulting in a certain combination of high pass frequency and Qtc.
Secondly, a low Q like 0.45 results in a flat response in contrast to high Q where a resonant response results and the diagram shows this well.
Last not least, in order to evaluate your "flat response" finding, it would be best to show your measurement results, so misunderstandings are avoided and we "sing from the same song sheet" 😉
Best Regards,
Winfried
First of all any loudspeaker system is a bandpass system, made up of a high pass and a low pass. The diagram shows the high pass part. The speaker shows a certain high pass characterisitc depending on chassis and enclosure, resulting in a certain combination of high pass frequency and Qtc.
Secondly, a low Q like 0.45 results in a flat response in contrast to high Q where a resonant response results and the diagram shows this well.
Last not least, in order to evaluate your "flat response" finding, it would be best to show your measurement results, so misunderstandings are avoided and we "sing from the same song sheet" 😉
Best Regards,
Winfried
5cm is not nearfield. Put the mic 1cm from the cone. Make sure that the subwoofer is also raised up off of the floor or this will also affect the measurement results.