Earl Geddes on bass frequencies. I'm not entirely clear on everything he wrote, however, he says:
1) low frequency room gain is bogus because rooms are too leaky.
2) use multiple subwoofers
3) locate those subwoofers as independently as possible (symmetry = bad)
4) locate one of those subs in a corner because it will see all the modes and do not place any others in corners (symmetry = bad)
5) In the first modal region (which I think is somewhere in the low bass region) use one sub and one sub only. Multiple subs don't help.
6) Bass room treatments help bass but harm high frequencies.
7) "When one knows that they will be using subs in all cases, then it makes no sense to try and extend the response of the mains" -- this one I understood clearly.
8) Take measurements - REW or HOLM impulse
9) Use digital signal processing.
10) Proprietary software -- BUMMER.
*note: Geddes did the software calcs for free when you bought his subs. Harman/JBL software is able to adjust for any and all subs and works in all room shapes. So the Harman software seems to be the holy grail as far as I know.
http://www.gedlee.com/Papers/multiple%20subs.pdf
Link to the power point slides:
http://www.gedlee.com/Papers/OptimalBassPlaybackinSmallRooms.pptx
1) low frequency room gain is bogus because rooms are too leaky.
2) use multiple subwoofers
3) locate those subwoofers as independently as possible (symmetry = bad)
4) locate one of those subs in a corner because it will see all the modes and do not place any others in corners (symmetry = bad)
5) In the first modal region (which I think is somewhere in the low bass region) use one sub and one sub only. Multiple subs don't help.
6) Bass room treatments help bass but harm high frequencies.
7) "When one knows that they will be using subs in all cases, then it makes no sense to try and extend the response of the mains" -- this one I understood clearly.
8) Take measurements - REW or HOLM impulse
9) Use digital signal processing.
10) Proprietary software -- BUMMER.
*note: Geddes did the software calcs for free when you bought his subs. Harman/JBL software is able to adjust for any and all subs and works in all room shapes. So the Harman software seems to be the holy grail as far as I know.
http://www.gedlee.com/Papers/multiple%20subs.pdf
Link to the power point slides:
http://www.gedlee.com/Papers/OptimalBassPlaybackinSmallRooms.pptx
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