Hey folks,
I am in the planning stages on my subwoofer project and want you guys to run a reality check on my ideas, plans, etc.
I have two Meniscus SW1238R 12" subwoofers:
Xmax: 13mm (one way)
Fs: 18hz
Qms: 10.04
Qes: 0.41
Qts: 0.395
Sd: 500 cm2
Vas: 170l
Le: 2.0
Nominal power handling ability: 200W
Re: 3.10 ohms
# of voice coils: 1
I have a closet that is behind the wall of the room my system is in....and it is in the corner of the room. I can utilize 17ft3 of the closet to place a sub enclosure (wife OK'd that space). I can net about 14ft3 of internal volume after bracing,ports,etc once I put a box in the closet. I would front fire the drivers and ports out from the right hand corner of the room near the floor (through an opening in the drywall). My room is 18' x 22' with 10' ceilings.
Wiring the drivers in series gives me Re=6.1 ohms. I run some various numbers though the latest version of 'Unibox' and I chose the following alignment:
Net Enclosure Volume: 400 liters (14ft3)
# of ports: 2 (3" x 17"/each)
Fb: 14 hz
max output (without room gain) at 20hz: about 110 db (excursion limited)
Power needed to reach 110db at 20hz: 260W
Port air speed: Only gets objectionable at 15hz.
I plan to use the 80hz low pass xover of the HT receiver for right now.
This alignment gives me a gentle 5db rolloff from 80hz to 17hz....which, with room gain should give me relatively flat response, in-room, down to 14hz. Response drops like a stone at 14hz. In reading JonM's discussion of 'room gain' and flat bass response, he noted that a 5db rolloff from from around 100hz to 20 hz usually gets a system bass close to flat, in-room. This alignment doesn't seem to require a special plate amp with their 'boost' circuits...from what I can discern, no boost is required.
I own a NAD amp that I can bridge to 400W into 8ohms, I have the woofers, I have the wood, and I have the wife's OK to build it as planned, I don't have to spend any money.......I am ready to start making sawdust.
Am I making good decisions here? :huh: I don't want boomy bass OR thin bass....I want bass as it should be. Please don't suggest other drivers or amps, I have this stuff on-hand and am trying to do the best I can with what I have.
Any thoughts from anyone......any at all? Please...feel free to give your thoughts/observations/opinions. :T
Many thanks,
Steve Paul
I am in the planning stages on my subwoofer project and want you guys to run a reality check on my ideas, plans, etc.
I have two Meniscus SW1238R 12" subwoofers:
Xmax: 13mm (one way)
Fs: 18hz
Qms: 10.04
Qes: 0.41
Qts: 0.395
Sd: 500 cm2
Vas: 170l
Le: 2.0
Nominal power handling ability: 200W
Re: 3.10 ohms
# of voice coils: 1
I have a closet that is behind the wall of the room my system is in....and it is in the corner of the room. I can utilize 17ft3 of the closet to place a sub enclosure (wife OK'd that space). I can net about 14ft3 of internal volume after bracing,ports,etc once I put a box in the closet. I would front fire the drivers and ports out from the right hand corner of the room near the floor (through an opening in the drywall). My room is 18' x 22' with 10' ceilings.
Wiring the drivers in series gives me Re=6.1 ohms. I run some various numbers though the latest version of 'Unibox' and I chose the following alignment:
Net Enclosure Volume: 400 liters (14ft3)
# of ports: 2 (3" x 17"/each)
Fb: 14 hz
max output (without room gain) at 20hz: about 110 db (excursion limited)
Power needed to reach 110db at 20hz: 260W
Port air speed: Only gets objectionable at 15hz.
I plan to use the 80hz low pass xover of the HT receiver for right now.
This alignment gives me a gentle 5db rolloff from 80hz to 17hz....which, with room gain should give me relatively flat response, in-room, down to 14hz. Response drops like a stone at 14hz. In reading JonM's discussion of 'room gain' and flat bass response, he noted that a 5db rolloff from from around 100hz to 20 hz usually gets a system bass close to flat, in-room. This alignment doesn't seem to require a special plate amp with their 'boost' circuits...from what I can discern, no boost is required.
I own a NAD amp that I can bridge to 400W into 8ohms, I have the woofers, I have the wood, and I have the wife's OK to build it as planned, I don't have to spend any money.......I am ready to start making sawdust.
Am I making good decisions here? :huh: I don't want boomy bass OR thin bass....I want bass as it should be. Please don't suggest other drivers or amps, I have this stuff on-hand and am trying to do the best I can with what I have.
Any thoughts from anyone......any at all? Please...feel free to give your thoughts/observations/opinions. :T
Many thanks,
Steve Paul
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