Looking for advice on subwoofer box with odd dimensions - AVS Forum

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DIY Speakers and Subs

denverb's Avatar denverb
02:17 PM Liked: 10
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Hey guys,
I am trying to get a subwoofer box built with these dimensions:
100 inches long 48 inches wide (depth looking at the box from an aerial view) and 10-11 inches high. At this point I have not selected a speaker. My hope is to get 2 18 inch subs in the box.

The trick is the top of the box must be flush. It has to be a smooth surface all the way across the top. Would you just build a box and mount the drivers on the inside versus the typical install type? Would you use something really thick and mill the wood so the surface will be flush (I am not very handy and have limited tools)? Will this have any adverse affect on performance?

Is there anyone that builds and ships these type of custom boxes?

If not I still need to research proper wood, screws, glue, stuffing, speaker connects, ported or sealed etc.

If it matters I am using Dynaudio Focus 380's matching center and B&K Reference amps. Room is 20ft by 12ft dedicated theater room with 8ft ceiling


Thanks in advance for any advice.


LTD02's Avatar LTD02
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got a pic of where this box goes?
chalugadp's Avatar chalugadp
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As long as the subwoofer depth is enough you can recess mount and will sit flush.

Shipping something that big will be crazy expensive. Better to do yourself or hire a local guy.
denverb's Avatar denverb
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Quote:
Originally Posted by LTD02 View Post

got a pic of where this box goes?

It will go under back row of theater seats




Just watching golf but you get the idea


LTD02's Avatar LTD02
03:09 PM Liked: 1170
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the consideration about dimensions isn't really an issue. several guys have built subs into "risers" like you plan to do. the trick in your case would seem to be getting drivers that are not too deep themselves to fit in the enclosure.

also, i'd suggest a ported cab with 16hz tuning. you probably have somewhere in the neighborhood of 20 cubic feet of internal space to work with and that is really good for max bass into the mid teens.
denverb's Avatar denverb
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Quote:
Originally Posted by chalugadp View Post

As long as the subwoofer depth is enough you can recess mount and will sit flush.

Shipping something that big will be crazy expensive. Better to do yourself or hire a local guy.

Thanks for the reply

Recess mount was the wording I was looking for thanks When you say recess mount you are not talking about mounting to the inside of the box rather having a lip in the box the has enough depth for the sub to sit down in with another lip to mount to? Perhaps using more than one sheet of wood...

I know there are a millions options do you have any personal advice on brand? It will need to be 4ohm and of course not need tons of depth space.

A friend recommended these to me but I don't want something that requires 2000 watts to drive. Plus they are capable of way more than I need. I am not trying to blow the walls down just want more deep bass for music and a better HT experience.

TC Sounds LMS Ultra 5400 18"
LTD02's Avatar LTD02
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here would be two subs, low profile that could be used as risers.

driver mounted from rear inside cab with protective grate over driver "just in case".
denverb's Avatar denverb
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Quote:
Originally Posted by LTD02 View Post

the consideration about dimensions isn't really an issue. several guys have built subs into "risers" like you plan to do. the trick in your case would seem to be getting drivers that are not too deep themselves to fit in the enclosure.

also, i'd suggest a ported cab with 16hz tuning. you probably have somewhere in the neighborhood of 20 cubic feet of internal space to work with and that is really good for max bass into the mid teens.

Thanks for the reply.
I agree volume should not be an issue will take note of the tuning. I am more worried about how to get the subs mounted correctly. Do you have an example of a riser? As I said I am not very handy but I think I can manage to build a rectangle as long as I understand how to mount the drivers.

for instance this is a random low profile driver. It is quite a bit higher than the lip you use to install. If you screwed this in from the back the driver would be hitting the wood. If you do a recess install that would make sense I just don't know how it would be done.


LTD02's Avatar LTD02
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"Recess mount was the wording I was looking for thanks When you say recess mount you are not talking about mounting to the inside of the box rather having a lip in the box the has enough depth for the sub to sit down in with another lip to mount to? Perhaps using more than one sheet of wood..."

yes.

just have to leave enough room for the driver to move forward if using a protective grill in front of it. not to scale. just for concept.



this driver is quite nice and is on double special this weekend.

http://www.parts-express.com/dayton-audio-um15-22-15-ultimax-dvc-subwoofer-2-ohms-per-coil--295-514

http://www.parts-express.com/pedocs/specs/295-514-dayton-audio-um15-22-specifications.pdf

a pair of them tuned to 16hz look something like this:



when powered with 550 watts each, which is what an inuke 3000dsp amp will do and that can be purchased for $250-300 delivered.
chalugadp's Avatar chalugadp
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Ltd has done it again. Problem solved smile.gif
denverb's Avatar denverb
03:41 PM Liked: 10
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Quote:
Originally Posted by LTD02 View Post

"Recess mount was the wording I was looking for thanks When you say recess mount you are not talking about mounting to the inside of the box rather having a lip in the box the has enough depth for the sub to sit down in with another lip to mount to? Perhaps using more than one sheet of wood..."

yes.

just have to leave enough room for the driver to move forward if using a protective grill in front of it. not to scale. just for concept.



this driver is quite nice and is on double special this weekend.

http://www.parts-express.com/dayton-audio-um15-22-15-ultimax-dvc-subwoofer-2-ohms-per-coil--295-514

http://www.parts-express.com/pedocs/specs/295-514-dayton-audio-um15-22-specifications.pdf

a pair of them tuned to 16hz look something like this:



when powered with 550 watts each, which is what an inuke 3000dsp amp will do and that can be purchased for $250-300 delivered.[/quote


Excellent thanks this is what I was looking for. I am using a B&K Reference 200.5 which is 375 watts at 4ohms per channel. I am not sure how that works with 2 2ohm coils but I can ask them about that.

LTD02's Avatar LTD02
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you want to run your subs off that amp? (just asking. for some reason that question doesn't sound right.)

if so, the coils simply get wired in series for 4 ohms per driver. one driver per channel on the amp.

the shape of the curve will be the same. just a couple db less with the lower power.

...

:-) d.
denverb's Avatar denverb
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Quote:
Originally Posted by LTD02 View Post

you want to run your subs off that amp? (just asking. for some reason that question doesn't sound right.)

if so, the coils simply get wired in series for 4 ohms per driver. one driver per channel on the amp.

the shape of the curve will be the same. just a couple db less with the lower power.

...

:-) d.

I suppose I am open to anything assuming there is an advantage using something else because I already own a couple of these. My current plan is to use 4 of the channels two for subs and two for some additional rears. I still have a long way to go anyway. I am going to poke around to forum to for materials to use. I will keep this post up to date for anyone else that may find this information useful.

I assume using something like this provides greater flexibility because you can tune to your liking and that is why it is recommended for sub use?
Martycool007's Avatar Martycool007
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Those amps may not be the most optimal amplifiers for subwoofers, nor the most cost effective. I would sell the B&K amp that you plan to use for these subs and get an iNuke3000dsp or an iNuke NU4-6000. Those are much higher powered amplifiers and cost less than the B&K amps. Subwoofers need more power than what you would typically use for other speakers, although, I would recommend the iNukes to power your other speakers as well ! smile.gif
denverb's Avatar denverb
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Quote:
Originally Posted by Martycool007 View Post

Those amps may not be the most optimal amplifiers for subwoofers, nor the most cost effective. I would sell the B&K amp that you plan to use for these subs and get an iNuke3000dsp or an iNuke NU4-6000. Those are much higher powered amplifiers and cost less than the B&K amps. Subwoofers need more power than what you would typically use for other speakers, although, I would recommend the iNukes to power your other speakers as well ! smile.gif

Thanks for the reply.
I am really pleased with the way the B&K sounds for the rest of the system it's amazing. For the subs I guess I will grab one of these instead of using the B&K.
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