26 Jun 2020, 09:57
Dayton Audio UM10-22
Closed, Vb: 21.9l
So I designed a subwoofer in SBL, basically a 325mm cube with an Dayton Audio Ultimax UM10-22. The graph in SBL shows 40Hz at -3.8dB and 30Hz at -6.2dB. Now I built it with a Monacor SAM-300D and measured it with my UMIK-1 and REW, and it measures 40Hz at 71.4dB and 30Hz at 55.9dB which is way off from what I was expecting. What am I doing wrong?
As I can see you have a very high slope, maybe you turned on subsonic or have any crossover in your system?
28 Jun 2020, 07:57
There's no configurable subsonic filter in the sub amp, and I've set the crossover to 200Hz (the highest setting). I've ordered a different sub amp now, Dayton Audio SPA500DSP. Hopefully I can tune it flat using the DSP.
1 Jul 2020, 09:06
You designed the box for a Dayton Element but built it with a Monacor…?
5 Jul 2020, 07:03
Just the plate amp... I didn't think that that should make a big difference in the box design other than the cutout.
I've put the Dayton Audio amp in there now and with the DSP I managed to flatten it out a bit, but it's still not great. https://i.imgur.com/2hd3eXX.png
24 Jul 2020, 03:54
So just a curious question did you add any bracing and account for the displacement if so
7 Aug 2020, 09:42
The 300D has a built in bass boost at 40 Hz. Depends on how they implemented it. If it's a high Q high pass it works as subsonic filter as well. That might be the reason of the steep slope and the reduced output at 30 Hz.
7 Aug 2020, 09:44
This isn't a Nearfield measurement, right ? So IMHO you are measuring the room as well at such low frequencies.