Three years to get around to my own install.

[soundstreamer]

I dont have as much of a history about Pro Tech speakers as you do. I do remember seeing them in a lot of the car audio magazines back in the day and as far as I know they were an in house speaker for PJ's Autosound in Erie, PA. I always wanted to stop in their shop but never had time as I used to go through Erie on my way to see my sister in Rochester NY. That's very cool you have a stash of their speakers and that slot ported box with 8 8's had to be pretty cool. I did get to hear a vehicle with 2 of their 12 inch subs many years ago at a show and was very impressed by them but I was also mainly a basshead back then.

[geolemon]

in house speaker for PJ's Autosound in Erie, PA. I always wanted to stop in their shop but never had time as I used to go through Erie on my way to see my sister in Rochester NY.

You are pretty local to me - I'm just south of Buffalo, NY in Orchard Park.
As far as I know, PJs definitely was one of the biggest customers - and that may have even been the original owner who owns PJ's, I don't know. I only was introduced when I met Mike. I don't have much - for a very short time my old garage was the warehouse, but Rich moved out, I moved in with my Fiancee, and I sold that old house, Rich still has a little stockpile, but there's just not much.
Part of me would love to take it over myself, have my own little side-business - but I've done my time in the industry. Retail is tough, I have done that as well, managed a shop, made purchasing decisions - and while I personally always wanted to support the little guy, I recognize that 90% of the people out there would buy a turd with an RF logo on it at 200% of the price of a truly well-engineered subwoofer they've never heard of. That's just sad reality.

[geolemon]

Ok, well I will get to this a little later and it will be some work to input it so stay tuned.

I wasn't looking to cause you lots of work - I do have some modeled.
If you want to validate or compare to these, that's definitely appreciated (especially since my W7 specs in my database at the moment are the minimal spec), but I'll load some of my graphs shortly, because there's some interesting findings already...

[geolemon]

So here's what I have so far - first the graphs, then the "experiments"

So you can tell "what is what", I made the W7 plots shades of blue, and the GTi shades of red.
For the signal, I put 600w - that's about what I'll give them (they each interestingly are 3 ohm nominal subs)

Frequency response:

Cone excursion:

Impedence:


**The sealed are the dark red and dark blue. Both totally normal.

**The PR are the brighter red (GTi) and blue (W7) I'm glad I didn't go smaller than 1.25 cu.ft... because even with the mass disc attached it's the equivalent of maybe a 38hz tune.
...I'll be playing with how much mass I need to add to get that closer to 30hz. Hoping to stay at 1.25 cu.ft.

**I modeled a "normal" vented box - the orange/red (GTi) and teal-blue (W7). For that, as expected I literally have to double my enclosure size.
I modeled up 2.35 cu.ft. vented at 29 hz (literally double the net size, with port displacement).

Interesting stuff:
--38hz tune with huge PRs? I didn't even think that was possible!
Makes me want to include a 38hz vented box with a "bigassports" vent and do an SPL comparison, too... We'll see.

--For "king of the hill" subs that have massive excursion capability - we're barely taxing them here!
That's not totally a surprise with these small-ish boxes, but note even if I *quadruple* the sealed box to 5 cu.ft., you finally cross the W7 Xmax at 25hz... and even then only if I nearly double my power to the full 1000w limit.

--It could even be said that these particular subs are somewhat of a waste for these applications... Which is one reason I wanted to start with these, then shuffle in some more "average" subs.
It's possible that they'll not only keep up with these, but if more efficient (as less capable subs frequently are) - surpass these in some ways!

[JCsAudio]

Oh sure, what a great offer... WinISD pro has some functionality for that and I've done a little modeling, but actually I didn't specifically run some alignments. Does BassBox Pro have a driver database with sufficient details (beyond Qts, Vas, and Fs) for these subwoofers?

• JL Audio 12W7
• JBL GEI Mk1 12"
• Adire Audio Brahma 12 (mine is a 2008 version, but I think it's the same as current)
• JL Audio 12W0 (version 1... going back into history)

The T/S specs for these PRs (these specs are with the bolt, but without the mass disc):

• Fs = 25.5 hz
• Vas = 4.52 cu.ft.
• Qms = 7.0
• Cms = 0.38661 mm/N
• Mms = 289 g
• Sd = 483 sq.cm.
• Xmax = 4 in (doesn't state 'one way' so I'm assuming that's peak-to-peak)

The mass disc that it comes with adds 255 grams, but of course other washers can be added, in combination with or substitution for that disc.

As for the enclosure - I've built a box that will net 1.25 cu.ft., using the displacement of the GTi 12 and W7 12 which have nearly identical displacement.
The Brahma won't be too far behind that, probably will work out to be about 1.3 cu.ft... and for the W0, I'd expect net displacement to be about 1.4 cu.ft. It's a little guy.

I'd have gone smaller on the box but I actually want to have a direct comparison to a 1.25 cu.ft. sealed - and also because I don't want to have a PR exposed to damage risk in my hatch, I'm going to fire the sub forward, have one PR on the back side, and one PR on the top - so really the smallest I would have gotten anyways is maybe 1/2 cu.ft. smaller.

Interested in what you model up, thanks!

Here is the first run with the W7. Something is off with those PR specifications but I put them in anyway. The Sealed and PR box are 1.25 net and the ported box is 2 cu ft tuned to 30 Hz.

JLW7 Sealed (red) vs Ported (orange) vs Yellow (PR) on 750 watts


I have specifications for a JBL W12GTi MkII but not what you listed?

[JCsAudio]

Adire Audio Brahma 12 Sealed (red) vs Ported (orange) vs Yellow (PR) group delay same box sizes as above on 750 watts

[JCsAudio]

JL Audio WO12D4 Sealed (red) vs Ported (orange) vs Yellow (PR) cone displacement on 300 watts which is pushing it to its limits.

[geolemon]

Here is the first run with the W7. Something is off with those PR specifications but I put them in anyway. The Sealed and PR box are 1.25 net and the ported box is 2 cu ft tuned to 30 Hz.

JLW7 Sealed (red) vs Ported (orange) vs Yellow (PR) on 750 watts


I have specifications for a JBL W12GTi MkII but not what you listed?

Interesting - do you know what's off with the specs? WinISD took them, maybe Bassbox has some validity checking that WinISD doesn't? Those are just from the spec sheet they came with - and note that doesn't include their 255g mass disc.

I am surprised at *MY* plot that shows the PR tune is effectively so high...
I dismissed that just because of the small size, but we'll have to see which plot is right!

Sent from my LM-G710 using Tapatalk

[JCsAudio]

Not yet but I can figure it out if I put my head to it. I already shut down the old laptop but can fire it up again tomorrow. Just off the top of my head the fs or the Mms in grams was off. Either the fs wanted to be 15 or the Mms 100 ish grams. Also your plot is higher because I think you used two PR and I used one.

[geolemon]

So here's a fun dilemma:
I want to be able to swap several subs back and forth into these boxes... and of course, each sub has it's own cutout.
The biggest - 11.125" cutout for the classic 10 spoke basket that I have on some prototypes and the Adire Brahma.
The smallest - 10.5" cutout for the 12W7... didn't expect that would be THAT much smaller.

My initial thought after measuring the JBL GTi with a pair of giant calipers is that I thought I could get away with a 10.75" cutout and that would be good for both the GTi and the W7 - and then I could make an adapter ring for the 10 spoke basket subs, with the taper of the frame it would fit fine.

Problem is - my giant caliper doesn't have giant arms, so I was trying to gunsight it down the arms - and clearly I measured wrong. The 11" cutout listed in the GTi 12 spec sheet must be actually legitimate...
So we'll flip that plan. I'll cut the holes at 11.125, then make an adapter ring for the W7 at 10.5". No biggie, other than "spacer + big excursion" is going to mean I need some real clearance in front of these boxes.
...in actuality, it could mean "easier swapping", because I can make a ring that the 12W7 stays permanently mounted to, and then I can just swap that whole assembly out.


I'm also going to try something that I think will just add a touch of professionalism to some otherwise boring, carpeted boxes.
I hate visible carpet seams, so I think I'm going to work some trim - maybe aluminum stock - in kind of a frame, an inch or so inside the outer perimeter of the sides.
That'll give me a clean set of lines to carpet to.
This is a home product and not the aluminum I have, but the picture is the closest thing that I can find to what I'm thinking, but just as an accent separating black carpeting from more black carpeting:


I also hate visible wires, which is going to be a challenge since I'd normally mount a terminal cup on one side or the other, but in this case I want the option to fire the box either forward or backwards, without having the wiring be visible - which pretty much leaves me the bottom. So I'm thinking about how to pull that off without spacing the box off the floor.

I'm leaning towards routering a groove all the way across the bottom, drilling a hole for a wire to exit the box (on either side, if I decide to reverse it), and then having a quick disconnect on the speaker wire path. To me, that's a lot better than a terminal cup on the speaker box, where [if disconnected for any period of time, to remove the box to use the hatch, etc] there's that risk of the two wires touching themselves or any metal, and presenting your amp with a dead short.