27-Oct-2015, 18:58
I'm by no means an expert on sub-woofer integration, although I have dabbled a bit. Please forgive me if I'm suggesting things you already know or tried out...
25 Hz seems a very low cross-over frequency to me, especially if your main speakers are bookshelf-sized. Something in the region of 80 Hz is more normally used. Maybe that would be worth experimenting with?
I would expect, as you did, that the 25 Hz high-pass filter on the main speakers shouldn't be having any noticeable effect at 100 Hz. However if the speakers are small I would also expect there's not much output from them anyway at 25 Hz.
Are you sure that the sub-woofer is receiving a low-pass filtered signal both when the mains get a full-range signal and when they're high-pass filtered? From what you've said it sounds as though maybe the sub is also getting a full-range signal when the mains are. At least, that's the only way I can understand what you described.
My other thought was to do with time/phase alignment of the sub-woofer with the mains. Unless you've taken some care to make it so, it's very likely that the sub and mains will not be in phase at the cross-over frequency. That is generally considered to be a requirement for good integration. Maybe some tinkering with the phase control on the sub-woofer would be useful. (Is it continuously variable, or just a 0/180 degrees polarity control?)
25 Hz seems a very low cross-over frequency to me, especially if your main speakers are bookshelf-sized. Something in the region of 80 Hz is more normally used. Maybe that would be worth experimenting with?
I would expect, as you did, that the 25 Hz high-pass filter on the main speakers shouldn't be having any noticeable effect at 100 Hz. However if the speakers are small I would also expect there's not much output from them anyway at 25 Hz.
Are you sure that the sub-woofer is receiving a low-pass filtered signal both when the mains get a full-range signal and when they're high-pass filtered? From what you've said it sounds as though maybe the sub is also getting a full-range signal when the mains are. At least, that's the only way I can understand what you described.
My other thought was to do with time/phase alignment of the sub-woofer with the mains. Unless you've taken some care to make it so, it's very likely that the sub and mains will not be in phase at the cross-over frequency. That is generally considered to be a requirement for good integration. Maybe some tinkering with the phase control on the sub-woofer would be useful. (Is it continuously variable, or just a 0/180 degrees polarity control?)
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