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Discussion Starter · #1 · (Edited)
(2) Infinity REF1262W, 9 ft3 (net), 18 Hz tune, BASH 500W

F3 at 22 Hz. F6 at 17 Hz.


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107 dB at 16 Hz. 111 dB at 20 Hz. 115 dB at 40 Hz. All 1 m GP. SPL is shown at Xmax (13 mm) of drivers.


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Stock Bash HPF (Fc 17.36, Q 0.817) is included for all graphs.


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Peak port velocity of 23.5 m/s.


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Complete WinISD project file attached.

1 5/8" Spax MDF screws and Titebond II are being used. The SPAX screws are especially made for use in MDF. They do not require pre-dilling and testing revealed they do not split the MDF as long as they are placed at least 2" in from any corner. Acrylic urethane caulk was used to secure the port tube in place. T-nuts for the drivers had a dab of Gorilla glue placed on them to prevent any possibility of movement.


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Any vertical braces going in?
 

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Discussion Starter · #3 · (Edited)
No vertical braces.

A 3/8" round over bit was used on all edges. All screw holes were then sanded flush using 120 grit. The entire surface area of the enclosure was also scuff sanded with 120 grit to help with primer adhesion. It has taken several applications of Ready Patch to completely fill the screw holes due to some minor shrinkage. Ready Patch was also applied along the seams and edges as needed to ensure smooth transitions.


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Looks great I bet you can't wait to fire that puppy up.....:clap:
 

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Discussion Starter · #5 · (Edited)
All screw holes, edges, and seams have been detail sanded with 180 grit. It's now ready for 2 coats of primer, which will be Zinsser Cover Stain (oil base). ~20 hours of labor to date. ~5 hours was filling/sanding screw holes, edges, and seams.

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Truly a labor of love. :T
 

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Discussion Starter · #7 ·
Texture is coming out just how I was hoping it would with 2 coats of Cover Stain rolled on with a 6" x 1/4" nap roller. At 18 hours post-application, the primer is already very dry and could be lightly sanded.

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Excellent job. :T
 

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Discussion Starter · #10 · (Edited)
Done; listening to it as I type this, but still have not had a chance to calibrate it. I will likely do that after "breaking it in" a bit.

Exterior dimensions (not including 1.5" tall feet) are 54" tall x 24" wide x 16" deep.
Assembled weight is ~125 lbs.
Total build time was ~35 hours.
Total build cost was ~$600.

I think my nickname for it will be the "Tower of Power". It reminds me a bit of the mysterious black monolith from 2001: A Space Odyssey! :D

Build log:

The (2) 4-ohm voicecoils in each driver were wired in series to give an 8-ohm load per driver. Readily available 16-gauge lamp cable was used and worked great due its low resistance at these lengths.


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(2) 3.5" layers of fiberglass insulation (R-13) were put on the bottom of the enclosure. This was done to counter the primary 129 Hz (1/2 wavelength) height resonance due to the internal 52.5" height. It may also help some with higher harmonics. All other primary enclosure resonances are well above the crossover point, so no other absorptive material was placed. The second layer of insulation was cut in the shape of an "H" to clear the basket and magnet structures.


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All wiring was securely attached and ran clear of anything that it could slap or vibrate on. Each 8-ohm driver was connected in parallel to yield a stable 4-ohm load for the plate amp.


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All assembled.


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Texture from 1/4" nap roller. 3 coats of Olympic One latex eggshell were applied over 2 coats of Zinsser Cover Stain primer. Primer was sanded fairly flat prior to applying top coats to keep the rolled texture from getting too aggressive.


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For size reference that is a 65" plasma and a SVS 20-39 PC+; the sub being replaced by this DIY.


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Discussion Starter · #11 · (Edited)
Things I would do different next time:

1) Oversize appropriate panels by 1/2" total. Then inset panels 1/4" on each edge, so there is a 1/4" overhang. After assembly, trim overhang with a flush trim bit to create an excellent transition between the panels. Follow-up with a round over bit as desired. This would have saved ~3 hours.

2) Have the enclosure sprayed with Line-X. Cost: $150 (I called after the fact to get an estimate.) Net Cost: only $100 more because primer, paint, and other painting supplies would not have been needed.

This would have saved time and anxiety on the top coats, which I had to be very meticulous about so that they would turn out nice - i.e. blowing/rinsing new rollers to help prevent shedding, lightly sanding out any shedding that still occured, wiping enclosure multiple times with a tack cloth between top coats, quickly applying paint and back rolling for uniformity, etc. Line-X also would have been fully cured (and fully durable) in less than an hour vs. the 2-week full cure time required for latex.

3) Install 2 recessed bar handles. Cost: $20

Still debating about this, because I think it might have made it look too "pro" audio. However, this thing is a beast to move and can only be moved now with a furniture dolly or a handcart. A recessed bar handle on each speaker side of the enclosure would have allowed two people to move it without the need for a dolly or handcart. Less chance of damaging the finish as well.
 

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Looks killer either way. I think your plan for a finish looks great also. You could have done Duratex or other finishes but do you plan on moving this cabinet very often?

I have Duratex on my pro audio cabinets with handles and corner protections. BUT I throw them around a lot and dont want to worry about damagin the cabinets.
 

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Discussion Starter · #14 ·
Looks killer either way. I think your plan for a finish looks great also. You could have done Duratex or other finishes but do you plan on moving this cabinet very often?

I have Duratex on my pro audio cabinets with handles and corner protections. BUT I throw them around a lot and dont want to worry about damagin the cabinets.
No plans on moving it often. I also tossed around the idea of adding some 2" casters, but I thought that would kill the look I was going for, too. Also considered using Duratex, but it would have been $70 to get it here. The qt of primer and qt of top coat that I used were bought locally for $23.
 

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Discussion Starter · #15 · (Edited)
How does the sub compare to the SVS?
Too soon to tell, as I have not calbrated it or broken it in yet. Theoretically, it should have about 8 dB more output than the SVS at 16 Hz, about 4 db more output at 20 Hz, and be roughly even at 32 Hz and up.

This is with the SVS in its standard 20 Hz tune mode. If the SVS were placed in 16 Hz tune mode by blocking one of the ports, the difference would be smaller at 16 Hz, but then larger at 20 Hz and up.

I designed my DIY so that it would purposely contrast with the SVS. The SVS uses (1) 12" long Xmax driver and a 525 W RMS amp with boost to reach low. On the other hand, my DIY uses (2) 12" shorter Xmax drivers and a 500 W RMS amp with very little boost (I went with the stock Q of 0.817). At roughly $400 less, my DIY should easily outperform the SVS at 20 Hz and below; the obvious trade-off being an enclosure that's roughly 220% larger - gross volume 9.9 ft3 vs 4.5 ft3.

I will report back later with my impressions, after some more time has elapsed and after calibration.
 

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(2) Infinity REF1262W, 9 ft3 (net), 18 Hz tune, BASH 500W F3 at 22 Hz. F6 at 17 Hz. 107 dB at 16 Hz. 111 dB at 20 Hz. 115 dB at 40 Hz. All 1 m GP. SPL is shown at Xmax (13 mm) of drivers. Stock Bash HPF (Fc 17.36, Q 0.817) is included for all graphs. Peak port velocity of 23.5 m/s. Complete WinISD project file attached. 1 5/8" Spax MDF screws and Titebond II are being used. The SPAX screws are especially made for use in MDF. They do not require pre-dilling and testing revealed they do not split the MDF as long as they are placed at least 2" in from any corner. Acrylic urethane caulk was used to secure the port tube in place. T-nuts for the drivers had a dab of Gorilla glue placed on them to prevent any possibility of movement.
This am be a simple question, but are the woofers moving in the same direction --kind of like a push-pull or are they both moving out at the same time and then in at the same time?
 

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Discussion Starter · #18 ·
This am be a simple question, but are the woofers moving in the same direction --kind of like a push-pull or are they both moving out at the same time and then in at the same time?
The woofers move in and out at the same time (i.e. they are wired in phase with each other). This alignment has the effect of cancelling the opposing cone motions as per Newton's 3rd law, and results in very little cabinet movement/vibration. This is one of the primary benefits of a dual opposed design.

Another benefit is that response changes very little with different orientations (firing into the corner, firing sideways, firing forward, etc). This allows for more placement flexibility.
http://www.data-bass.com/data?page=content&id=77
 

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Discussion Starter · #19 · (Edited)
That's very impressive work. Congratulations to you!
Thanks. There was a slight learning curve, but all in all I think it turned out quite well.

As far as how it performs compared to the SVS 20-30 PC Plus that it replaced, I think my DIY does better - a conclusion I reached after doing some A-B testing between the subs.

To test, I put both subs next to each other in my listening area and then individually level calibrated each using my receiver's sub tone. I then played identical source material and switched between the subs listening for differences. This was repeated several times. To my ears, my DIY went lower and had more impact with HT. It also sounded just as good with music. This is admittedly a very subjective test, so take it for what it's worth.

For more objective measurements, I plan to take my DIY outside one day and do some GP measurements with REW and a calibrated mic. I also am very curious to see how well it matches up with its design/theoretical performance as determined by WinISD.
 

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wow! impressive work! and the name just suits it best! may i ask how do i open .wpr file which is in the attachment? sorry but i'm still a newbie and i do want to learn more.. thanks!
 
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