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This is a spin-off from the Most BASS for the $$$ thread.
Since finishing my HT earlier this year, I've been cruising a lot of the DIY subwoofer threads here. I bought 2 of the JBL GTO1514D subwoofer drivers... seemed like an affordable way to get started.
Last year I bought the plans for the THTLP (Tuba Home Theater Low Profile) and was originally going to build that, but it looks like the F-20 might be a little simpler to build. Plus I already had a couple of sheets of 3/4" ply in the garage that I needed to use. The THTLP insists on 1/2" ply, which I didn't already have, so I'd have to buy 3 sheets.
There are already a couple of good F-20 build threads. And since this is my first build, I'm sure they're probably better than I'll do. But the main F-20 thread is a little overwhelming, so this thread is mainly just notes to myself where I can consolidate my thoughts as I step through the build this week.
I'm currently using two 15" subs behind my AT screen, leftovers from the HT I built 10 years ago in our previous house:
My inuke 3000DSP from ebay arrived today.
I drew a cut list to see if I could use the large scrap piece of ply I already had.
Only needed to buy one sheet.
So I got started.
I'd borrowed my friend's table saw. But I've borrowed it before and struggle with cutting large panels, especially since I'm usually working by myself. I could never cut a straight line with a circular saw... seems like the harder I try, the worse it gets.
So I did some googling on "building a jig to make cuts with a circular saw" and came across this thread. Too long... didn't read. So I just skimmed down to the picture at the bottom captioned "Make your cut" and thought "I can do that!"
I went to Home Depot, got a 16' long piece of 1"x2" finger-jointed pine ($6.44, only used half of it) and a 4x8 sheet of Tempered Hardboard ($13.44, only used 12" of it)... used my air stapler to staple the hardboard to the 1x2. Then ran my circular saw down each side, using the 1x2 as an edge guide. Voila... the blade just made its own cutting guide. I clamped it (using 2 of these $2.99 clamps from HF) to a 4x8 sheet and made my first cut.
OMG. I wish I would've learned this 40 years ago. I've never seen such a straight cut. Since the edge of the jig was cut with the blade of my own circular saw, it cuts exactly where it's clamped... no messing with drawing a line, no worrying about the thickness of the pencil line or the angle that you hold the pencil, no slipping straightedge as you try to draw a long line, no need to guess the width of the blade's cut width (kerf), no need to blow sawdust out of the way so you can see your pencil line as you cut.
Clamp the edge of your jig on your measured marks, place the saw on the jig, slide the saw along the edge of the 1x2. Perfect cut.
You can easily see exactly where the cut line will be by looking at the edge of the jig, so I used 2 folding tables to hold each side of the panel I was cutting. I just needed a gap as little as 1" between the tables. And I could push the saw from anywhere I could reach... no need to see the line, just push along the edge of the 1x2. Oh well... too much rambling over something so simple. Probably obvious to most of you, but maybe there's someone else out there that can't do straight cuts with a circular saw.
I cut 11 panels in about 30 minutes. Used a pencil to check off my cut list and labeled each board as panel 1-11.
Halfway though the cuts, UPS dropped off this box... contents: 15" JBLs, qty: 2.
You can see my fancy "sawdust management system"... a quick blast from the leaf blower after each panel.
Now to go read the next step on how to draw the points on the side panels to play connect-the-dots tomorrow with a jumbo tube of PL.
Gasket tape, speaker terminals, and duratex on the way from PE.
Since finishing my HT earlier this year, I've been cruising a lot of the DIY subwoofer threads here. I bought 2 of the JBL GTO1514D subwoofer drivers... seemed like an affordable way to get started.
Last year I bought the plans for the THTLP (Tuba Home Theater Low Profile) and was originally going to build that, but it looks like the F-20 might be a little simpler to build. Plus I already had a couple of sheets of 3/4" ply in the garage that I needed to use. The THTLP insists on 1/2" ply, which I didn't already have, so I'd have to buy 3 sheets.
There are already a couple of good F-20 build threads. And since this is my first build, I'm sure they're probably better than I'll do. But the main F-20 thread is a little overwhelming, so this thread is mainly just notes to myself where I can consolidate my thoughts as I step through the build this week.
I'm currently using two 15" subs behind my AT screen, leftovers from the HT I built 10 years ago in our previous house:
- Definitive Technologies Powerfield 15
Dimensions 17 1\\2H by 17W by 17D
Freq. response 18-125hz
Driver complement One 15" woofer with polymer laminated cone
Amplifier 200 wattsRMS
High pass filter 12db/octave selectable (50 or 100 cycles)
Low pass filter 24 db/octave continuously variable (50 or 100 cycles)
- Cerwin Vega LW15
Woofer size 15"
Nominal (RMS) output power 200 Watt
Response bandwidth 27 - 150 Hz
Crossover frequency 40 - 120Hz
Enclosure material MDF
Weight 72.3 lbs
My inuke 3000DSP from ebay arrived today.
I drew a cut list to see if I could use the large scrap piece of ply I already had.

Only needed to buy one sheet.
So I got started.
I'd borrowed my friend's table saw. But I've borrowed it before and struggle with cutting large panels, especially since I'm usually working by myself. I could never cut a straight line with a circular saw... seems like the harder I try, the worse it gets.
So I did some googling on "building a jig to make cuts with a circular saw" and came across this thread. Too long... didn't read. So I just skimmed down to the picture at the bottom captioned "Make your cut" and thought "I can do that!"
I went to Home Depot, got a 16' long piece of 1"x2" finger-jointed pine ($6.44, only used half of it) and a 4x8 sheet of Tempered Hardboard ($13.44, only used 12" of it)... used my air stapler to staple the hardboard to the 1x2. Then ran my circular saw down each side, using the 1x2 as an edge guide. Voila... the blade just made its own cutting guide. I clamped it (using 2 of these $2.99 clamps from HF) to a 4x8 sheet and made my first cut.

OMG. I wish I would've learned this 40 years ago. I've never seen such a straight cut. Since the edge of the jig was cut with the blade of my own circular saw, it cuts exactly where it's clamped... no messing with drawing a line, no worrying about the thickness of the pencil line or the angle that you hold the pencil, no slipping straightedge as you try to draw a long line, no need to guess the width of the blade's cut width (kerf), no need to blow sawdust out of the way so you can see your pencil line as you cut.
Clamp the edge of your jig on your measured marks, place the saw on the jig, slide the saw along the edge of the 1x2. Perfect cut.
You can easily see exactly where the cut line will be by looking at the edge of the jig, so I used 2 folding tables to hold each side of the panel I was cutting. I just needed a gap as little as 1" between the tables. And I could push the saw from anywhere I could reach... no need to see the line, just push along the edge of the 1x2. Oh well... too much rambling over something so simple. Probably obvious to most of you, but maybe there's someone else out there that can't do straight cuts with a circular saw.
I cut 11 panels in about 30 minutes. Used a pencil to check off my cut list and labeled each board as panel 1-11.
Halfway though the cuts, UPS dropped off this box... contents: 15" JBLs, qty: 2.
You can see my fancy "sawdust management system"... a quick blast from the leaf blower after each panel.

Now to go read the next step on how to draw the points on the side panels to play connect-the-dots tomorrow with a jumbo tube of PL.
Gasket tape, speaker terminals, and duratex on the way from PE.