I have a pretty big order to fill.
I currently have a 9 cubic foot enclosure housing a single 18" McM pa subwoofer driver. My brothers and I built it 12 years ago and it's still running strong. However it's output and bass extension is unacceptable. I would like to modify the enclosure to fit two 15" drivers.
My goal is extension to 20hz. I personally am not too interested in output below that. Right now the 18" has usable output down to 30hz, at low spl.
Are there any drivers on the market right now that cost not much more than 200 dollars each that would fit the bill?
I currently have a 9 cubic foot enclosure housing a single 18" McM pa subwoofer driver. My brothers and I built it 12 years ago and it's still running strong. However it's output and bass extension is unacceptable. I would like to modify the enclosure to fit two 15" drivers.
My goal is extension to 20hz. I personally am not too interested in output below that. Right now the 18" has usable output down to 30hz, at low spl.
Are there any drivers on the market right now that cost not much more than 200 dollars each that would fit the bill?
I assume you are going with a sealed enclosure? With that much enclosure you might be able to go with a pair of 18's. Maybe something like these: Fi. Assuming you are just using them for subwoofer duty. I think the inductance is fairly high on those so you wouldn't be getting much above the subwoofer range.
Otherwise the Dayton RSS390HF-4 are pretty highly regarded inexpensive 15's that would work well in an enclosure that large.
Otherwise the Dayton RSS390HF-4 are pretty highly regarded inexpensive 15's that would work well in an enclosure that large.
I would second the RSS 390 HF drivers from Dayton Audio, sold by Parts Express. These don't have over 20mm Xmax (more like 15mm), but I would be surprised if your old pro driver has over 5mm Xmax.
Another option would be to go with three 12" subs. There is one that comes to mind, sold by Creative Sound Solutions (CSS), called the Trio 12 ($150ea) that has 20mm Xmax and a good motor.
-Charlie
Another option would be to go with three 12" subs. There is one that comes to mind, sold by Creative Sound Solutions (CSS), called the Trio 12 ($150ea) that has 20mm Xmax and a good motor.
-Charlie
Hi hornloaded,
If you have a little time, these are currently out of stock, due 6/27/2012:
TC Sounds Epic 12" DVC Subwoofer 293-650
or on the low end of the price scale (but may need a bigger box if vented):
http://www.parts-express.com/pe/showdetl.cfm?Partnumber=295-206.
Regards,
If you have a little time, these are currently out of stock, due 6/27/2012:
TC Sounds Epic 12" DVC Subwoofer 293-650
or on the low end of the price scale (but may need a bigger box if vented):
http://www.parts-express.com/pe/showdetl.cfm?Partnumber=295-206.
Regards,
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Using slot loading you could potentially fit as many as four 18" speakers or six 12" speakers in that baffle size, with room for ports on the front.
Four 15" would easily fit.
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(I I)
"(" = cone, "I" = slot, viewed from cabinet front.
The speakers could be mounted push pull (with the "backwards" cones wired with reversed polarity if you wish to reduce even order harmonic distortion.
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Art
The Alpine SWR1522D is a 200 dollar 15" that has a 21mm xmax and reaches 20HZ flat in a 4 cubic foot ported box tuned to 20HZ. I run one in my living room system with a dayton 1000watt class AB plate amp and its really clean sounding high quality bass. I get really good output even at 15hz. Use a 6" port. I run a 2.5x15.5 vent but it kicks up the box volume over 5 cubes for the vent volume.
I run the exact same 4 cube net box with that 15 in my hummer with a Rockford Fosgate 4000watt amp and I cant believe the power it takes after all these years.
Run the specs for yourself. Its for real. The SWR1542D is two 4 ohm coils instead of the dual 2's in the 1522 and it needs a 5 cube net box extending to 19HZ flat. The advantage of the dual 4's for me was the higher damping factor since power wasnt an issue but tighter bass from better control was audible. I've run both models.
Hello hornloaded,
The Dayton TIT400 for ~$233 each comes to mind. 20.5mm xmax....
As far as venting 2 of these in a 9ft^3 box goes... That is a bit problematic. I suggest tuning below your desired bandwidth to avoid chuffing issues. A 6" flared port, as long as will fit on the longest dimension of that box (~30" length), should get your tuning down around 15hz, and your peak air velocity @Xmax@20hz down to a reasonable 15m/s.
The simulation below is at ~2000W@1M
Regards,
Eric
The Dayton TIT400 for ~$233 each comes to mind. 20.5mm xmax....
As far as venting 2 of these in a 9ft^3 box goes... That is a bit problematic. I suggest tuning below your desired bandwidth to avoid chuffing issues. A 6" flared port, as long as will fit on the longest dimension of that box (~30" length), should get your tuning down around 15hz, and your peak air velocity @Xmax@20hz down to a reasonable 15m/s.
The simulation below is at ~2000W@1M
Regards,
Eric
Attachments
That 15 is asking for a huge box for optimum ported at over 10 cubes but flat to 18hz is impressive. If you have the room for it, its a good cheap alternative with a copper shorting ring.
Hi SpinMonster,
I don't think it's "asking" for a box that large at all. When all considerations are taken in, like thermal limits, excursion limits, typical room response, etc, 4-5ft^3 per driver is actually a very good region to be in. Giving it a larger box is fine, but not necessary.
Regards,
Eric
I don't think it's "asking" for a box that large at all. When all considerations are taken in, like thermal limits, excursion limits, typical room response, etc, 4-5ft^3 per driver is actually a very good region to be in. Giving it a larger box is fine, but not necessary.
Regards,
Eric
I used the word optimum and was relaying what WINisd said was best for max flat extension. I guess 4 cubic feet with a -3db point at 27hz and a 1db ripple at 55hz is good too but it isnt optimum. At 5 cubes sealed you would be at 35hz -3 with a much slower roll off and no group delay issues. 4 cubes ported to low 20's will have a long port at 6" diameter....so you would be near 4.7 cubes net.
It looks good both ways.
What are the sound quality changes/characteristics of using a smaller than optimum ported box?
Hello SpinMonster,
In this context, are we still talking about a number that winISD spits out? The problem with this question, is that the word "optimum" has a very pre-loaded, misguiding effect. It's like the old cliche, when you want a confession, ask a question where all answers result in the admission of guilt. IE: "Were you wearing a hat when you killed your wife?"
WinISD pro has 5 different options to choose for calculating an "optimum." Among those 5, it will spit out [roughly] 3 different box volumes, and 4 different tuning frequencies in various arrangements. So which one of those is "optimum?" The answer: none of them. They are just different.
In this case, I think the "optimum" box is the one that doesn't have to be built. We have a 9ft^3 box already constructed, that makes it very "optimum" in my eyes
The effects of the "undersized" vented compared to "maximally flat optimum" apply to about half an octave of the lowest useful range of the design.
1. Reduced efficiancy.
2. Reduced maximum SPL.
3. Reduced Group delay.
4. Increased Xmax limited Pe
As far as distortion or other related issues are concerned, the difference is probably very negligible.
Regards,
Eric
In this context, are we still talking about a number that winISD spits out? The problem with this question, is that the word "optimum" has a very pre-loaded, misguiding effect. It's like the old cliche, when you want a confession, ask a question where all answers result in the admission of guilt. IE: "Were you wearing a hat when you killed your wife?"
WinISD pro has 5 different options to choose for calculating an "optimum." Among those 5, it will spit out [roughly] 3 different box volumes, and 4 different tuning frequencies in various arrangements. So which one of those is "optimum?" The answer: none of them. They are just different.
In this case, I think the "optimum" box is the one that doesn't have to be built. We have a 9ft^3 box already constructed, that makes it very "optimum" in my eyes
The effects of the "undersized" vented compared to "maximally flat optimum" apply to about half an octave of the lowest useful range of the design.
1. Reduced efficiancy.
2. Reduced maximum SPL.
3. Reduced Group delay.
4. Increased Xmax limited Pe
As far as distortion or other related issues are concerned, the difference is probably very negligible.
Regards,
Eric
Perhaps the best fit instead of two cheaper drivers is to use one TC sounds LMSr15 which works nicely in a 6-9 cubic foot box and costs the same as the two cheaper drivers that you may be comtemplating. Its 433 each rather than two 200 dollar drivers giving up some extension to make them fit.
In this fitment you would be using some of the internal volume to house a bigger vent system but still is a nice fit all around for that driver with really low distortion and a 19hz extension. The LMSr 15 also has a 29mm Xmax so it sweeps 50% more air than a 20mm xmax sub.
In addition, you didnt memtion what amplification you have, unless I missed it, as two 15's may or may not set the impedance where your amp will be best with. If you have a single bridged amp needing no lower than 4 ohms, then two 4 ohm drivers arent going to be as good as a single 4 ohm 15 that is a better fit for the existing box you have.
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Hi SpinMonster,
There's no on-paper advantage to the TC driver over the 2xTIT400s. Both configurations will hit Xmax ~2000W, both configurations will be limited to about 120dB@1M@20hz, however, the 2xTIT400s will play an average 3dB louder through the majority of the remaining bandwidth for the same power input and in doing so, produce a more room friendly response.
Regards,
Eric
There's no on-paper advantage to the TC driver over the 2xTIT400s. Both configurations will hit Xmax ~2000W, both configurations will be limited to about 120dB@1M@20hz, however, the 2xTIT400s will play an average 3dB louder through the majority of the remaining bandwidth for the same power input and in doing so, produce a more room friendly response.
Regards,
Eric
I guess it comes down to my post pointing out the final inpedance of the system. If his amplifier makes 2000 watts (or its best power) into 8ohms, the 2 dayton 15's may fit his need. If his amplifier makes its 2000watts (or best power) into 4 ohms, the TC will be the better way to go as the other system will likely lose 3db or so to the lower amp power at the higher impedance. I didnt note the TIT400 coming in an 8 ohm version.
My bet would be the stronger motor of the TC 15 for SQ & Its 33 bucks cheaper.
Did he mention what amp he has?
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