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Discussion Starter #1
1st of all, Hello! I've been reading extensively on this forum trying to educate myself,but have instead kinda confused myself with too much info. :doh:
I've noticed that the forum tends to be very helpful and friendly though.

What i am trying to accomplish is basically a 15" Dayton sub for home theater use (80-90%) primarily and a about 20% music. I really want it to shine in the HT department though. I have a Denon AVR991 and Dayton 6.5" bookshelf speakers in a 5.1 setup. ( possibly upgrading them in near future).

As far as a sub goes, i have a 26"w x 17" h x 66"L area to work with for an enclosure,seems roomy enough....thats why i was thinking a 15" would be nice. Id like to incorporate a plate amp on the enclosure as well. The enclosure will go under our bed in our bedroom as we have a small unobtrusive system in the living room. We really want OUR entertainment system in our bedroom (20x13x9)to be the nice one.
Id like to use about 300-500w plate amp and possibly a 15" Dayton sub (unless suggested otherwise).

From the research ive done,it seems like a low tuned ,ported enclosure is what im after. If at all possible,id like to design a simple to cut and assemble enclosure,because this is my first DIY.
Any help/suggestions are greatly appreciated !
Thanks in advance.
 

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Discussion Starter #3
I'd like to keep the subwoofer at 200.00 or less. and the amp about the same.
Ive been playing around with the dayton HF 15",but am not sure about my skill with the modeling software.
Also the ports have been giving me fits as far as proper tuning.
 

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Discussion Starter #6
Dayton HF as in RSS390HF?
Yes, the Dayton Audio RSS390HF-4 15" , sorry for the incomplete info.

I was wanting to do a down-firing configuration,if thats ok with that woofer. From the info ive gathered,it seems that larger,lower tuned enclosures seem to be the ticket when going with just one sub especially. I've seen several designs for 300L-350L ported to 16hz.

If that seems to be right,how do i accurately calculate the proper port sizes and length(thinking round),and then calculate they're displacement,so i can account for that in the enclosure vol?
 

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Down firing will subtract 4" from the height for the legs so the internal dimensions of the cabinet will be 24.5"w x 11.5" h x 64.5"L. That would be a 10.5 cu.ft internal volume. Subtract 1 cu.ft. for ports, bracing and driver volume leaves 9.5 cu.ft which the driver models well in.

Porting would be two P.E. 4" flared ports used full length, this gives the box a 18.5 tuning frequency. You can power it with a Bash 300 watt amp which would be at its limits or a 500 watt amp which will give you a bit of power reserve.

For figuring out displacement of ports and bracing click on the link below.

http://www.hometheatershack.com/forums/enclosure-volume-calculator/


390HF.JPG
 

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Discussion Starter #8
Thanks a lot! I appreciate the link.
Not too throw a wrench into the work you've put into this,but,,,,,, i did a little thinking this morning (before coffee) and started sketching a slightly more complex enclosure shape than just a equal sided rectangle. The area where the sub will mount would be the internal dimension you quoted above ( 11.5") for the 1st 20" of box length. Then it would increase in depth to use more of the available 17" of depth. ( figured 16" outside for wiggle room) That would make the remaining depth of the enclosure 14.5" deep. I thought the extra added depth would allow the enclosure to be shorter.
I just dont know if the additional 3" of depth is worth the added degree of build difficulty. but an added 3" over a say, 24.5"x 48" area is about 2cuft.
I also realize that the ports would need enough room to clear in length...cant make the too short.
Q: In your experience ,would there be any benefit with this driver to tune any lower? Or is the 18.5 hz a good sweet spot? just trying to optimize everything.
Thanks in advance.
 

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Discussion Starter #10
If i make the deeper section 36" long (outside dimension) i get 9.2cuft internal vol. 9 not including bracing ,sub or ports) ( thats 56" overall outside)

If i go 40" long on the deeper section (outside dimension) i get 9.9cuft. Not including ports,sub,bracing. (60"overall,outside)
So i guess the deeper section is saving me approx 6"-10" in length overall...not that big of a deal i guess.
 

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Discussion Starter #12
after looking at what it would take to put that "step" into the enclosure, i think the simpler design is better for me. I dont want to over complicate my 1st build.

One thing i am considering though, is to change the design to up firing.

It looks like (correct me if im wrong) i can go with a 9.1cuft gross internal vol (12x29x56 outside) which should net me 8cuft with ports,bracing,sub. If i tune to 16hz it models to 109-110db @ 20hz.
Am i on the right track,or just chasing my tail? Maybe over-thinking things?
Thanks again for your help.
 
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