Impossible.
Efficiency is at best inversely proportional to cabinet size. Cut cabinet size in half from a reasonable 4 cubic feet (for 40Hz exension) and efficiency goes down 3dB.
Efficiency is at best inversely proportional to the cube of the low frequency cut-off. Increase bass extension in a small speaker from 80Hz to 40Hz and its efficiency decreases 9dB.
Switching to separate woofers (I wouldn't really call an enclosure covering up to 80 or 100Hz a sub-woofer) will help with small main-enclosure size.
>Current speakers are Usher 6381, large speakers that I believe are too big for my room.
Provided that you can sit far enough from multi-way speakers for the drivers to integrate properly (10' should do it) you can't have speakers too big for the room.
With a small room and high fundamental resonance you may get room gain in the audio pass-band; although a high-pass filter may be a better option than changing speakers. Your room's fundamental resonance is at 24.6Hz so this isn't an issue.
>Room is an open design roughly 23' wide, 12' deep and vaulted ceilings 8-12' high. Listening area is 15' wide as opposed to the 23'. Speakers must go along the wide wall at 10' apart, one speaker is in a corner. Listening position is 10' from the speakers. I can pull the speakers out at most 2' away from the walls, depending on how large the cabinets are.
Your biggest problems are the speaker in the corner, the speakers too close to the front wall, and your seat too close to the back wall. NO speakers are going to provide high-fi performance with that asymetric placement without changes to the input signal.
At low frequencies speakers are completely omnidirectional. A 100Hz wave is 11' long and wraps around any speaker you can fit in your living room like it isn't there. Most audiophile speakers have the on-axis sound cut at high frequencies so there's more output at low frequencies to compensate for this loss. When the front or side wall is nearby wall the energy is not lost and the reflections are closer to in-phase so they add for a big bass (through lower midrange in extreme cases) boost. This can be 5dB for one wall or 10dB in a corner which provides Bose-like frequency response and sound (good frequency response isn't +/- 1dB before you get the room involved).
Sitting nearer to the wall increases the frequency below which all frequencies add-in phase with their rear wall first reflection. Getting too close (6' is probably a good number, since it keeps the first reflection 10ms out) also means that your brain is integrating more of the rear-wall first reflection into the direct sound at high frequencies.
Shelving high-pass filters (as on a pro-sound parametric equalizer) or DSP room correction (Audyssey, TACT, DEQX, etc) will fix the excessive bass problem. A piece of rigid fiberglass (preferably thicker) on the wall behind your seating position will help, with such products available with attractive fabric (even printed) coverings for increased spousal acceptance.
Ripping some favorite tracks, measuring with an inexpensive Radio Shack SPL meter, correcting for C weighting, and adjusting those tracks with free software (maybe Audacity?) before writing them to a CD-R would be interesting. Stop correction at a few hundred hertz - your worst problems are at low frequencies and at low enough frequencies your brain needing a few cycles to pickup a tone means steady-state power response is a reasonable approximation of what you hear.
There may also be modal issues.
Efficiency is at best inversely proportional to cabinet size. Cut cabinet size in half from a reasonable 4 cubic feet (for 40Hz exension) and efficiency goes down 3dB.
Efficiency is at best inversely proportional to the cube of the low frequency cut-off. Increase bass extension in a small speaker from 80Hz to 40Hz and its efficiency decreases 9dB.
Switching to separate woofers (I wouldn't really call an enclosure covering up to 80 or 100Hz a sub-woofer) will help with small main-enclosure size.
>Current speakers are Usher 6381, large speakers that I believe are too big for my room.
Provided that you can sit far enough from multi-way speakers for the drivers to integrate properly (10' should do it) you can't have speakers too big for the room.
With a small room and high fundamental resonance you may get room gain in the audio pass-band; although a high-pass filter may be a better option than changing speakers. Your room's fundamental resonance is at 24.6Hz so this isn't an issue.
>Room is an open design roughly 23' wide, 12' deep and vaulted ceilings 8-12' high. Listening area is 15' wide as opposed to the 23'. Speakers must go along the wide wall at 10' apart, one speaker is in a corner. Listening position is 10' from the speakers. I can pull the speakers out at most 2' away from the walls, depending on how large the cabinets are.
Your biggest problems are the speaker in the corner, the speakers too close to the front wall, and your seat too close to the back wall. NO speakers are going to provide high-fi performance with that asymetric placement without changes to the input signal.
At low frequencies speakers are completely omnidirectional. A 100Hz wave is 11' long and wraps around any speaker you can fit in your living room like it isn't there. Most audiophile speakers have the on-axis sound cut at high frequencies so there's more output at low frequencies to compensate for this loss. When the front or side wall is nearby wall the energy is not lost and the reflections are closer to in-phase so they add for a big bass (through lower midrange in extreme cases) boost. This can be 5dB for one wall or 10dB in a corner which provides Bose-like frequency response and sound (good frequency response isn't +/- 1dB before you get the room involved).
Sitting nearer to the wall increases the frequency below which all frequencies add-in phase with their rear wall first reflection. Getting too close (6' is probably a good number, since it keeps the first reflection 10ms out) also means that your brain is integrating more of the rear-wall first reflection into the direct sound at high frequencies.
Shelving high-pass filters (as on a pro-sound parametric equalizer) or DSP room correction (Audyssey, TACT, DEQX, etc) will fix the excessive bass problem. A piece of rigid fiberglass (preferably thicker) on the wall behind your seating position will help, with such products available with attractive fabric (even printed) coverings for increased spousal acceptance.
Ripping some favorite tracks, measuring with an inexpensive Radio Shack SPL meter, correcting for C weighting, and adjusting those tracks with free software (maybe Audacity?) before writing them to a CD-R would be interesting. Stop correction at a few hundred hertz - your worst problems are at low frequencies and at low enough frequencies your brain needing a few cycles to pickup a tone means steady-state power response is a reasonable approximation of what you hear.
There may also be modal issues.