Hi,
For my under the sofa subwoofer this is what I am going to do:-
1) Make two boxes of 6th order bandpass using 6.5 sub driver in each box ie both sides ported, technically. Bandwidth is 25Hz to 100hz, that's 2 octaves well within limits of this alignment
2) Now to save space actually use PRs on both the sides instead of ports to make two small enclosures. With placement slightly apart I ensure that there are four sources on the high side, the four sources spaced apart help prevent localization. The fact that the bandpass is acoustically filtered on the high side further helps suppress localization.
There are deliberate four sources, on the 100Hz high side, to form sort of a small line array, they add up considerable SPL due to near placement to each other as well as near placement to anyone on the sofa. Anywhere else in the room I dont care.
The 6.5' drivers are used to extract the most from the 6th order alignment I will never feel SPL lacking.
What do you think?
Warm Regards,
WonderfulAudio
For my under the sofa subwoofer this is what I am going to do:-
1) Make two boxes of 6th order bandpass using 6.5 sub driver in each box ie both sides ported, technically. Bandwidth is 25Hz to 100hz, that's 2 octaves well within limits of this alignment
2) Now to save space actually use PRs on both the sides instead of ports to make two small enclosures. With placement slightly apart I ensure that there are four sources on the high side, the four sources spaced apart help prevent localization. The fact that the bandpass is acoustically filtered on the high side further helps suppress localization.
There are deliberate four sources, on the 100Hz high side, to form sort of a small line array, they add up considerable SPL due to near placement to each other as well as near placement to anyone on the sofa. Anywhere else in the room I dont care.
The 6.5' drivers are used to extract the most from the 6th order alignment I will never feel SPL lacking.
What do you think?
Warm Regards,
WonderfulAudio
A single 6.5" driver will be quite limited at 25 Hz. But if you're ok with that - good.
The 25 Hz PR needs to have a lot of displacement. Either big Xmax or Sd.
At 25Hz, the pair of 6.5" PR at 20mm excursion are only capable of ~100dB output, sounding about as loud as 40dB at 1kHz. It will be interesting to feel how your couch cushions resonate at various frequencies.
The 4x5" PRs only require 1mm excursion for 100dB output.
There will be a "hot spot" ("butt ticklers") transmitted through the sofa cushions by each of the four sources.
I think experimenting with speakers under your couch to find out where your room peaks and nulls lie before committing to the under couch build would be a good idea.
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