Box design for Dayton Audio DCS385-4 15" Classic Sub

Ninesvnsicks · 2011-12-12 12:30 pm

mdocod said:
As for the port box and port designs...

I would go with a box shape of roughly 19.5" x 25.5" x" 34" or something similar. Front baffle "inside" dimension is then 18"x24" assuming 3/4" wall thickness (less a few inches top or bottom for port slot). I suggest doubling the front baffle thickness to 1.5" (glue-n-screw 2 sheets together). Bolt the woofer down really good.

I would build the port into the front of the box as a "slot" style port. on the bottom. 18" x 2.25" opening, 24.5" length. That should give about a 23hz tuning and the final box should wind around ~7ft^3. With 160W signal level (highest the unit should be played at to prevent distortion/over excursion) the air velocity in port will peak ~35ft/s just below 20hz. The port should be nice and silent through the useful listening range.

I'd use a round-over tool on the router (just a smallish round-over, like 3/8") and run it around the vent opening, also, i would apply a round over to the back of the baffle that makes up the top of the vent slot.

I'd certainly suggest rabbit jointing in a few braces and lining the inside of the box and braces with a thin layer of fiberlgass or polyfill.

I do not have the tools to do rabbit joints so liquid nails and screws will have to do. I'm still not sure on what type of wood to use I'd like something that looks good stained. I still have 4" pvc pipe left from my last build I might just use 2 round 4" ports just because if I do a slot port and it would probably have to do an L corner and I don't have a table saw to do 45 degree angles. I don't want to have to use stuffing (assuming that's what you meant by poly fill.) If I need bracing I could use round wooden dowels I've seen others use them before.

Ninesvnsicks · 2011-12-12 10:17 pm

mdocod said:
As for the port box and port designs...

I would go with a box shape of roughly 19.5" x 25.5" x" 34" or something similar. Front baffle "inside" dimension is then 18"x24" assuming 3/4" wall thickness (less a few inches top or bottom for port slot). I suggest doubling the front baffle thickness to 1.5" (glue-n-screw 2 sheets together). Bolt the woofer down really good.

I would build the port into the front of the box as a "slot" style port. on the bottom. 18" x 2.25" opening, 24.5" length. That should give about a 23hz tuning and the final box should wind around ~7ft^3. With 160W signal level (highest the unit should be played at to prevent distortion/over excursion) the air velocity in port will peak ~35ft/s just below 20hz. The port should be nice and silent through the useful listening range.

I'd use a round-over tool on the router (just a smallish round-over, like 3/8") and run it around the vent opening, also, i would apply a round over to the back of the baffle that makes up the top of the vent slot.

I'd certainly suggest rabbit jointing in a few braces and lining the inside of the box and braces with a thin layer of fiberlgass or polyfill.

Ok I keep hearing 100w-160w isn't this a 300w rms sub woofer? Shouldn't it take 300wrms?

revboden · 2011-12-12 10:24 pm

Ninesvnsicks said:
Ok I keep hearing 100w-160w isn't this a 300w rms sub woofer? Shouldn't it take 300wrms?

No, in a BR box drivers are limited by Xmax not rated rms.

Ninesvnsicks · 2011-12-12 10:26 pm

What is a BR box? As far as I know I was building the same kind of box I have built for my cars and the subs always handled rated rms or more.

revboden · 2011-12-12 10:35 pm

BR = bass reflex. (ported) Auto subs are a different critter, often used in an undersized box tuned high, you use lots of power in an undersized box. thus your experience.

Ninesvnsicks · 2011-12-12 10:37 pm

revboden said:
BR = bass reflex. (ported) Auto subs are a different critter, often used in an undersized box tuned high, you use lots of power in an undersized box. thus your experience.

ah ok well I'm fine with it using less than it's rated because my amp will be able to give it clean power than but 100w vs 300w seemed like a large amount less. Right now I'm thinking of doing the 7cuft tuned to around 23hz what do you think it would handle at that? SQ is what matters since it's for my dad but I do want it to be plenty loud if possible.

mdocod · 2011-12-12 10:42 pm

If you have winISD then you should already have your answer to that, just switch to the "max power" display.

(150W)

The difference between 150W and 240W is only 2db, so don't fret about it.

revboden · 2011-12-12 10:55 pm

here's an example of that driver one tuned for SQ and one tuned for SPL.

Ninesvnsicks · 2011-12-12 10:58 pm

mdocod said:
If you have winISD then you should already have your answer to that, just switch to the "max power" display.

(150W)

The difference between 150W and 240W is only 2db, so don't fret about it.

Yup I have 3 versions of winisd only one has the box creater part which is the most important part. alpha, beta and the newest 0.7.2 or whatever also bass box 6 pro. I'm going to check them all out now.

revboden said:
here's an example of that driver one tuned for SQ and one tuned for SPL.

I'm not sure how to read the cone excursion graph.

revboden · 2011-12-12 11:10 pm

The red line at 9.3mm is the Xmax of that driver. that wavy line moves as you change 'system input power' to show excursion per frequency.

oops. you can't see the bottom of the graph... the first green vertical line on the left is 20hz second 30hz etc.

Ninesvnsicks · 2011-12-12 11:15 pm

Ok so far I'm thinking 7 cuft at 23hz would be good I'm looking into Pro-rabbit from caraudio.com building it for me if the shipping and price isn't too much. It would be sub and slot port on front with 45 degree angles and rounded edges inside.

revboden · 2011-12-12 11:19 pm

Here's your 7ft/23Hz design. vs 12ft/18Hz. for reference.

Ninesvnsicks · 2011-12-12 11:22 pm

you put different wattages for the 2nd one and I'm not sure which is which lol. The 2nd one went way over xmax at 161w

mdocod · 2011-12-12 11:23 pm

Woops... yea, ~160W, not 150W maximum... I brought up the wrong dayton driver.

mdocod · 2011-12-12 11:24 pm

You don't need to worry about it going "way over xmax" down at like 13hz because you aren't going to be using that range anyays.

revboden · 2011-12-12 11:27 pm

you know what that chart shows now

Yes, at 161w if a signal has information below tuning, because that amps HP is set at 18Hz, you will push the driver past xmax. although most drivers have about 1/4 more excursion before you hit Xmech. So it shouldn't be a problem as long as you limit either the levels or the signal sent to the amp.

Ninesvnsicks · 2011-12-12 11:27 pm

mdocod said:
You don't need to worry about it going "way over xmax" down at like 13hz because you aren't going to be using that range anyays.

Ok so I'm probably going to set the crossover to 80hz what do you think it will handle between 20hz-80hz?

revboden said:
you know what that chart shows now Yes, at 161w if a signal has information below tuning, because that amps HP is set at 18Hz, you will push the driver past xmax. although most drivers have about 1/4 more excursion before you hit Xmech. So it shouldn't be a problem as long as you limit either the levels or the signal sent to the amp.

Yea I'll be careful at first and make sure I don't blast it and set the gain so it doesn't distort or kill the sub. I can't wait to hear it tho my dad hasn't had anything good for a long time right now he has a 60w realistic from like 15 yrs ago that is falling apart so this is going to be a giant step up. Next step after the sub is to make the speakers to match.

revboden · 2011-12-12 11:32 pm

Handle? if watts, same as above. The LP has no effect on power handling.

mdocod · 2011-12-12 11:33 pm

Well, it will "handle" anything from about 20-200hz I imagine, but the 7ft box is really more optimized for the 30-100hz range. Which for listening to music is ideal.

Ninesvnsicks · 2011-12-12 11:34 pm

mdocod said:
Well, it will "handle" anything from about 20-200hz I imagine, but the 7ft box is really more optimized for the 30-100hz range. Which for listening to music is ideal.

Yup that is what my dad will be doing with it. I was afraid that the amp wouldn't be giving it enough clean power but now that I know it will be handling less wattage it shouldn't be an issue at all now. Thank you for all the help guys I really appreciate it hopefully when it is all done and running I will take a video of it to show you

Box design for Dayton Audio DCS385-4 15" Classic Sub

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