Tweet
Hi Cam,
It’s going to be impossible to compare the Tempest to the BP without seeing readings from both, with both in the same location. The first set of numbers you gave for the Tempest were missing a lot of frequencies compared to the ones for the BP.
Perhaps it’s changed since you moved it, but the readings you posted for the BP are anything but “flat.”
But they do explain the problem you’ve been having. You have a 20dB hole centered at about 46Hz, and it’s a full octave wide. That explains why DVD’s sound so anemic, and it also explains why you keep damaging the driver. It takes a lot of excursion to get the kind of numbers you’re generating below 30Hz. Turning up the sub to compensate for the 20dB hole at 46Hz hole obviously sent the driver into convulsions. It’s a wonder the BP doesn’t look like the driver in the picture I posted the other day.
You’ve already tried to EQ the hole, and it didn’t work. That seems strange. True, you can’t EQ a null, but I’ve never seen a null that was a full octave wide. Typically they’re only 1/6-octave or so. It’s hard to say why the EQing didn’t take without knowing the frequency centers, bandwidth etc., but once you equalize you should be very happy with this sub. Jeepers, I wish it were mine!
It would be best to find a location somewhere that will minimize the 46Hz hole. Once you do that, post some 1/6- or 1/12-octave numbers and we can try some filters.
As others have noted, you need to watch your SPL levels with those sine waves. Sine waves are similar to a constant-voltage signal, which is very hard on a voice coil. All you need is to be above ambient room noise. We know that 46Hz is your low point – As long as 46Hz reads at least 65dB or so, you should be fine for the other frequencies.
Regards,
Wayne A. Pflughaupt
It’s going to be impossible to compare the Tempest to the BP without seeing readings from both, with both in the same location. The first set of numbers you gave for the Tempest were missing a lot of frequencies compared to the ones for the BP.
It is a fairly flat to begin with, just that dang 40-50Hz dip that unfortunately
is noticable when watching DVDs.
is noticable when watching DVDs.
But they do explain the problem you’ve been having. You have a 20dB hole centered at about 46Hz, and it’s a full octave wide. That explains why DVD’s sound so anemic, and it also explains why you keep damaging the driver. It takes a lot of excursion to get the kind of numbers you’re generating below 30Hz. Turning up the sub to compensate for the 20dB hole at 46Hz hole obviously sent the driver into convulsions. It’s a wonder the BP doesn’t look like the driver in the picture I posted the other day.
You’ve already tried to EQ the hole, and it didn’t work. That seems strange. True, you can’t EQ a null, but I’ve never seen a null that was a full octave wide. Typically they’re only 1/6-octave or so. It’s hard to say why the EQing didn’t take without knowing the frequency centers, bandwidth etc., but once you equalize you should be very happy with this sub. Jeepers, I wish it were mine!
It would be best to find a location somewhere that will minimize the 46Hz hole. Once you do that, post some 1/6- or 1/12-octave numbers and we can try some filters.
As others have noted, you need to watch your SPL levels with those sine waves. Sine waves are similar to a constant-voltage signal, which is very hard on a voice coil. All you need is to be above ambient room noise. We know that 46Hz is your low point – As long as 46Hz reads at least 65dB or so, you should be fine for the other frequencies.
Regards,
Wayne A. Pflughaupt
Comment