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Pair of Sealed Dayton 18" Flat-Pack Subs Build - Page 2

post #31 of 50
3/12/13 at 4:56pm
Thread Starter 
Assembly pics...

"bottom" side of assembly (really the back of the sealed enclosure).



Titebond 3 in background...a rubber mallet is handy at this stage to gently tap the three braces into position in their rabbeted grooves.



I used the pneumatic finish nailer to shoot 1.5" brads at the joints of the braces to better tie them into each other.
Must be from my framing days...the more ways it's tied together, the better.
Is it needed here?...why not?











That's it! I'll have the second done in no time and assembled like the first.

Once glue joints are cured in about 24 hours, I will seal all internal seams that are exposed to the exterior of the enclosure with white silicone caulk.

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post #32 of 50
3/12/13 at 5:13pm
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All interior seams now caulked and cured on both boxes.
Have just finished sanding some light spackle spots and seams.
Will be applying one coat of dark-tinted BIN primer to both enclosures tonight and then taking a break for several days to attend to business.
Will take more pics and post prior to/after DuraTex application.

Thought I would add the two photos below of the newly arrived DuraTex and EP4000 amp (the CV5000 is heavier than this???...holy crud!).
My miniDSP is waiting for me at the local post office. That's just about the last of my needed parts!



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post #33 of 50
3/12/13 at 5:18pm
nice progress, i recomend moving the sub boxes without subs and doing the final install close to their location. things are fing heavy

also the furniture sliders are a godsend if you have carpet
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post #34 of 50
3/12/13 at 5:22pm
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Sibuna...if I run the Y-adapter, it will allow me to run the subs in stereo?
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post #35 of 50
3/13/13 at 6:14pm
Thread Starter 
Getting ready soon to stuff my sealed enclosures with fiberfill.
Is there a good rule of thumb on the amount to use?
Would I be able to use something like "Morning Glory Premium Polyester Fiberfill, 5 lb. Box" from Wally World?
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post #36 of 50
3/13/13 at 8:08pm
aprox 1 lb per cubic foot is what most do
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post #37 of 50
3/14/13 at 1:50pm
The 1 lb/cu ft recommendation is very common, but I hadn't seen data on the effect until recently. There's an interesting experiment in Dickason's LDC showing the effect on FR and impedence of a wide variety of sealed box stuffing materials, densities and configurations. 1 lb doesn't look so good compared with some other choices. The most low end response comes with 4 lb.cu ft. fiberglass, either alone or 50/50 with a lesser density of fiberglass or fill. I've been using the real stuff in my subs for a while, and while I can't say I put in 4 lb.cu ft., it's packed real dense into the corners... got to leave free space for driver excursion.

As always, it try and see what you like!

HAve fun,
Frank
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post #38 of 50
3/14/13 at 2:28pm
Quote:
Originally Posted by blah450 View Post

Getting ready soon to stuff my sealed enclosures with fiberfill.
Is there a good rule of thumb on the amount to use?
There is none. You use it to lower the Q of the cab, assuming it needs to be lowered. The only way to know if you've added enough is to measure the box Q, with a WT3 or the equivalent, or measure the response outdoors to make sure there's no hump in the response. The higher the box Q is to start with the more stuffing you need to bring it down. But if Q is less than roughly 0.8 to begin with there's no need to stuff it at all, just line it with two to three inches of damping.
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post #39 of 50
3/14/13 at 5:22pm
Thread Starter 
Quote:
Originally Posted by fbov View Post

The 1 lb/cu ft recommendation is very common, but I hadn't seen data on the effect until recently. There's an interesting experiment in Dickason's LDC showing the effect on FR and impedence of a wide variety of sealed box stuffing materials, densities and configurations. 1 lb doesn't look so good compared with some other choices. The most low end response comes with 4 lb.cu ft. fiberglass, either alone or 50/50 with a lesser density of fiberglass or fill. I've been using the real stuff in my subs for a while, and while I can't say I put in 4 lb.cu ft., it's packed real dense into the corners... got to leave free space for driver excursion.

As always, it try and see what you like!

HAve fun,
Frank

Thanks for your couple of responses during my build, Frank. They have been informative.
Do you have a link to Dickason's LDC that you were referencing above?
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post #40 of 50
3/14/13 at 5:28pm
Thread Starter 
Quote:
Originally Posted by Bill Fitzmaurice View Post

There is none. You use it to lower the Q of the cab, assuming it needs to be lowered. The only way to know if you've added enough is to measure the box Q, with a WT3 or the equivalent, or measure the response outdoors to make sure there's no hump in the response. The higher the box Q is to start with the more stuffing you need to bring it down. But if Q is less than roughly 0.8 to begin with there's no need to stuff it at all, just line it with two to three inches of damping.

Hey, Bill. From the many posts of yours I have read, your sonic knowledge is in another dimension far beyond mine at this time. Apologies in advance for the prehistoric rookie questions:

How does one measure the box Q? What is the "box Q"?

What is a WT3?

You would recommend 2-3 inches of damping WITH fill AND without?

2-3 inches of damping would be achieved using what material and for what benefit?

Sorry for the rapid-fire questions...but I WILL try to move up the sonic evolutionary ladder...with a helping hand here and there I hope.biggrin.gif
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post #41 of 50
3/14/13 at 6:49pm
Have seen this build come up a lot lately...yours is looking good too. Interested in how they come out.
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post #42 of 50
3/14/13 at 7:20pm
Quote:
Originally Posted by blah450 View Post

How does one measure the box Q? What is the "box Q"?
Look here:
http://www.bcae1.com/spboxad2.htm
Quote:
What is a WT3?
Woofer Tester 3. It tests raw driver specs and finished cab parameters, including Qtc. You also will get a predicted Qtc when modeling the driver/box combination. That can tell you if you should bother to stuff the cab, but if you do you can only see the result by measuring it.
Quote:
You would recommend 2-3 inches of damping WITH fill AND without?

2-3 inches of damping would be achieved using what material and for what benefit?
Damping and fill are the same thing. You damp all cabs to control internal reflections. If you also need to lower Q you stuff it.
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post #43 of 50
3/14/13 at 8:14pm
Quote:
Originally Posted by blah450 View Post

Thanks for your couple of responses during my build, Frank. They have been informative.
Do you have a link to Dickason's LDC that you were referencing above?
LDC Loudspeaker Design Cookbook by Vance Dickason, 7th ed. Lots of data and equations, but you see how things work.
http://www.amazon.com/Loudspeaker-Design-Cookbook-Vance-Dickason/dp/1882580478

In this case, for one driver/box combination...
Dacron, Acousta-Stuff, fiberglass, acoustic foam
50%, 100%, 50/50
Fiberglass at 1, 2, 4 lb/cu ft.

Granted, most of the changes occur through the midrange more than low bass, but data extends to 20Hz... you can see why folks suggest trying different amounts!

Have fun,
Frank
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post #44 of 50
3/16/13 at 12:30pm
Thread Starter 
I would imagine come type of screw that is meant for MDF with pre-drilling and is NOT bugle head style would be best for mounting the drivers to their respective baffles??
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post #45 of 50
3/16/13 at 6:08pm
i used #6 wood screws which may be a bit small

many go with #10 spax screws which are beefy
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post #46 of 50
3/19/13 at 5:24pm
Thread Starter 
I'm back at it again...been out of commission for a while.

Thx, Sibuna.
Just posted a separate thread about the fastener and MDF question...thought some people might share their strategies and fasteners of choice when mounting drivers to MDF.
I did see the plywood backing blocks...nice idea.

Will have pics of finished cabs before driver install.

By the way, 4" roller is fine with DuraTex. Just make sure you use the one they offer or a similar one that is made of material that will not wick moisture like the soft sponge rollers.
The vertical application of DuraTex with a sponge roller goes wonky with moisture for some reason.cool.gif
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post #47 of 50
3/21/13 at 4:54am
Thread Starter 
Pics pre-driver install later tonight...I hope.

Planned on using 12-gauge in-wall speaker wire for my amp to sub runs of 60' and 50'...should be okay...yes?

Why speaker wire instead of the shielded RG6 coax I use currently?????
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post #48 of 50
3/22/13 at 8:41pm
blah450 - What binding post did you use?
I've ordered these from PE, http://www.parts-express.com/pe/pshowdetl.cfm?&Partnumber=260-284
I like binding posts to be recessed into the sub for placement options close to wall, and also that in moving it I won't grab a binding post by mistake.


How did your DuraTex paint job come out?
Did you hit the hard edges with a router round over bit or leave them as is?
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post #49 of 50
3/31/13 at 12:17pm
Thread Starter 
mtb...I like what you used, likewise your sound rationale for using them.
I did not want to bother with a cut...so I used the bare binding posts that go through a 1/4" pilot hole and stick out about 1 cm. from the back of the enclosures.

I had considered a small round-over edge for all the the edges, and it could easily be done, and it would have looked great...however, another step I did not want to take (boy...I'm coming across really chintzy. eh?).
I detail some of the DuraTex findings in Post 46, and will let you be the judge of it in the pics below. A second coat is HIGHLY recommended. Also, two of Erich's 4 cu.ft. cabs might possibly be completed with about a quart rather than gallon of DuraTex.

Also, I finally got around to drilling a hole in a test scrap of MDF and trying a brass knife thread insert to mount the drivers. Had some trouble with them not wanting to pull through quickly. Opted out of that after trying several different means of mounting including opening up the pilot hole a little more. Rather than mess around with having inserts align perfectly with screws, I followed the lead from others and just went with screws...just too darn quick and convenient! I found the below pocket-head screws at Lowes. I used #8 by 1.5", the head was easily wide, and the underside flat enough, to securely hold the flange of the Dayton 18" HO subwoofers. Being pocket-hole screws, it was a nice, wide, deep thread that held in the MDF very well. I did drill pilot holes despite the "cut-point" of the screws allowing for an easy start.

After returning the other hardware, total cost for a pack of these screws was $5.








Sub #1 (not sure what I will be doing with the eD A5-350 now. It's been really solid...just wanted to try something else with the DIY.


Sub #2...No spots on sub in following...just funky artifacts from camera...frown.gif





I have hooked them up just to make sure everything is powering up correctly....and cause I was too flipping excited!

Beacuse of a great deal, I opted for a Matchbox HD to take the unbalanced RCA feed from the Y off my receiver, and give me balanced XLR output on 2 lines...and therefore the ability to control FR of each sub via the miniDSP below.

My next step is to bring the 2 XLR wires to the miniDSP post Matchbox (I will cut the XLR cables in half and just use bare wire to feed in and out of DSP phoenix connectors) and then out to amp. I picked up a RatShack Enercell 12vDC 500mA wall wart with a bare wire adapter end to feed power to the miniDSP...they were on sale, so why not? I know what I am getting instead of playing a guessing game with an unused cell phone adapter.

I am running 12AWG speaker wire bare off amp to speakers.

Will be setting up calibrated Dayton Audio USB mic soon and playing around with placements and tuning.
I can already understand why some have said, "Why stop at 2?" biggrin.gif
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post #50 of 50
3/31/13 at 12:31pm
Thread Starter 
I am hooking up an "open" 2x4 balanced DSP with an "advanced" plug-in.
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AVS › AVS Forum › Audio › DIY Speakers and Subs › Pair of Sealed Dayton 18" Flat-Pack Subs Build