Three years to get around to my own install.

[geolemon]

Because isn't that always the way?

And actually - it's partly because I was leasing, but I love the car, so I'm just buying it out. Already installed heated seats which was a fun adventure.

They always start out so boring.

Stay tuned, giving myself two options out back.

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[geolemon]

Sneak peek teaser - already pulled these out of storage and (literally) dusted them off.

Here's the two I'm starting with, to fit the tiny spot I'm willing to give up in the hatch - just the area behind the smaller fold-down seat.

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[Cutaway]

Really excited for you!!! I hope you take us along for the adventure.
I had forgotten all about Earthquake, man i was a huge fan of their stuff back in the early 90's till i went team moon and stars

[JCsAudio]

I think I see a passive radiator there.

[geolemon]

I think I see a passive radiator there.

Two of them, since my intent is to try that box out with some pretty high excursion subs.

I'm sort of going into this install backwards, just based on what I have and what I'm still deciding. So - building the subs first.

I've been playing with PRs a bit in general... Had two (of my current favorite) eights with these 10" PRs in my last car.

Then I decided to make use of some of my other audio gear in my storage unit with this garage sale find antique radio. Actually have some great mids and tweets in there, Seas mids with Focal T90K tweets... With a super generic, relatively wimpy unmarked 12" sub that I think I picked up for like $20 at some manufacturer buyout sale, and used those 10" PRs that were on my shelves... Just a fun Frankenstein monster to make friends laugh - that actually came out sounding great. Even the sub, though it would be tighter with a better sub.

These 12" Earthquake PRs I bought because they actually seem engineered well. I like that they come with a mass ring (and a spec sheet baseline at that mass) that can not only be added to, but also removed and reduced - and look to have huge excursion capability.

We'll see how they actually perform, but Earthquake seems to stand behind them, pushing them, creating other products and official projects with them that they brought to trade shows - in my experience that's a sign of those "hidden jem" type products, so I'm optimistic.

I probably will end up building 3 boxes actually:
-- sealed, 1.25 cu.ft
-- passive radiators, 1.25 cu.ft
-- vented - TBD, but an intentionally generic compromise that works decent across my subs. I'd guess something like 2 cu.ft at 30hz.

I'll probably also swap in my Brahma 12, and probably pull a cheap or old school sub from the unit... I have an an ancient JL 12W1, just for fun comparisons. But that will have to wait until further down the road.

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[soundstreamer]

Wow haven't seen some Pro Tech subs in a long time. From what I remember those were really good sounding.

Love the old radio setup that would be a fun project to do.

[JCsAudio]

Geolemon,

I have an interest in learning more about modeling passive radiator setups with different subwoofers and since you seem to have a need or want to try those out and are not sure on the specifics yet, I may be able to help you with that? I have Bassbox pro and it has the capability to model different types and sizes of passive radiators. If you give me the specifications then I should be able to help you out? Bass box pro can also provide you with cut sheets that you can use as the basis of your design. Please let me know if you’re interested.

John

[geolemon]

Wow haven't seen some Pro Tech subs in a long time. From what I remember those were really good sounding.

Love the old radio setup that would be a fun project to do.

Thanks, it was fun - it sounds way better than I expected my "glorified bluetooth speaker" to come out.

How long ago did you hear of them? My history with them is pretty interesting-

They were a brand "back in the day", then they started to fade, and the original owner sold the company to an enthusiast who was running the company on the side, as just a fun little "lifestyle business".
I met him, Mike, coincidentally local to me, from my other ties in the industry back in the '00s.
I ended up doing some work with him when GE Capital sold an entire branch of business that I had been working in IT - he worked sales for an aerospace electronics manufacturing company, and got me a fun temporary job there while I idled a bit (had 8 months of severance pay from GE), and ultimately I ended up as one of three principal members of an SMT electronics contract manufacturing business also serving the aerospace company among others, which was a fun time for a few years, as I was the technical guy who programmed and ran all aspects of the robotic, automated SMT line. Google SMT pick and place machine, for fun. It's how circuit boards are made, although aerospace require much tighter tolerances and layers of inspections, than consumer electronics.

It was about the 1 year mark where the SMT business hit the $1M revenue milestone, so Mike decided to sell ProTech to focus on the 9-5 better...
...he ended up selling it to my very good buddy Rich. Rich kept some of the products going over time, and tried to work with the build houses to bring a few new products out (I was glad to help with that on a purely volunteer basis, this really was just fun, for both of us), but Rich was also going to medical school at the time (he's about 8 years younger than me, and was living in my basement apartment - I had just gone through a divorce so the roommate was great). Eventually it was just too hard to run - he had some local shops but of course 99% of enthusiasts only know brand names, and sales fell off (Mike was a much better sales expert). So today, there's not much happening.

In my storage unit, I do have a few ProTech subs - the 12 I've actually never used. The two eights - I did an install for a buddy of mine with eight of those eights, slot vented - it honestly was the "holy grail". It sounded good on everything. I own four of them, so maybe someday I'll do a half-size equivalent of that box.

[geolemon]

Geolemon,

I have an interest in learning more about modeling passive radiator setups with different subwoofers and since you seem to have a need or want to try those out and are not sure on the specifics yet, I may be able to help you with that? I have Bassbox pro and it has the capability to model different types and sizes of passive radiators. If you give me the specifications then I should be able to help you out? Bass box pro can also provide you with cut sheets that you can use as the basis of your design. Please let me know if you’re interested.

John

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!

[JCsAudio]

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