Ours will have a larger cavity behind it and will be side vented. This should yeild better quality sound.

If you can do it with a stock appearance and minimal or no loss in legroom, you've got a customer lined up right here. Amp is ready with a fifth channel, and I'm holding off on buying a subwoofer until I see your setup.

Thank you for doing this!

That's exactly what we are shooting for. Just been a bit busy with the fiberglass today.

Just a few notes from an audio geek -

Vented enclosures are a tuned system, meaning the port size is very much dependent on the driver's specifications and internal volume of the enclosure. The advantage of a vented enclosure over a sealed box is only power efficiency and SPL. The trade-off is that vented enclosures are typically a lot larger than than sealed boxes, and that the boosted frequencies from the port are usually a pretty narrow frequency range.

If you vent the enclosure but it's not done in accordance to the driver's specifications you'll end up screwing the pooch. You'll get peaks at a higher frequency that the sub isn't able to play - for example it might actually be quieter than a sealed box at normal sub frequencies and then have a big peak of volume at 300 hz which it isn't playing anyway. Since a ported box is open, the sub also requires that all of its suspension comes from it's spider and voice coil, and if it's not tuned correctly you can over drive it more easily than you could with a sealed box which, in a way, keeps the driver under better control.

My advice would be to make the largest sealed box you can throw at this project using a subwoofer that works great in smaller, sealed enclosures, and mate it with a high powered class D amp. The class D amps are so small they easily fit under the dash.

If you must go ported, you need to model it using any number of free software apps to make sure it's all makes sense. Again, I'm not sure if you're planning on offering this with a woofer, which would be the only way a tuned, vented box would work. If you're not offering the box with the sub, then it really has to be a sealed enclosure.

Sorry if this is all stuff you already knew.

Cheers!

Very interesting, and appreciated. Wonder if the solution isn't to have a port with a screw-on lid? Then the owner can experiment?

Running a 5-channel amp by JL, with a Class D mono for a sub (I think...need to go look at the box, as it's been sitting a long while—as better audio in my 914 has been pretty low down the list!).

My preference is for a sealed box. If it is vented, I'll just wind up sealing it myself. I'm looking for the tight punch of a sealed box rather than big boom of ported anyway. Louder is not necessarily better.

FWIW, you can see my sub installed on a foot board a couple pages back. Sounds like shit compared to mounted in a box. Even just running this sub in the cardboard box it shipped in sounds way better than free air on the board. Sure, even on the board it sounds way better than not having a sub at all, but it really needs a proper enclosure to get the best sound. For keeping foot space, I'm planning to bottom mount my sub under the face and install an expanded metal grate over it to protect the cone from feet.

Also, my Class D amp fits nicely inside the center console for a completely stealth install.

Not enough airspace to be vented.

Easier to sell un-vented.

Just checking on the status of the sub boxes @Mikey914

Tooling underway 3 weeks give or take for parts.

Thanks! Can't wait to give them a shake down.

My stereo is actually pretty neat but its missing a sub, this would round out the sound really well...can't wait!

A little late to the party, but here's mine. 6" between the seats. I have bumped my elbow a total of two times. Otherwise I don't notice it's there (aside from the THUMP THUMP).

Is that a JL Audio 8" sub? That was the first one I bought for my car and the sound was amazing! Unfortunately, it didn't quite fit in the footwell recess for a full stealth installation but man do I miss that sound. I kind of wish I had never heard it now. So tight and punchy.

I remember experiencing Troy's foot thumper. It took up no more space than the OG footwell foam piece. And it worked! The carpet over it, so stealthy. The right grill and you don't have to worry about foot damage like Rob's. Footwell has so much better bass potential.The thump is always better coming from the feet.

@Mikey914 Any updates on these?

Still working on the tooling to mass produce these. Should be January

Thanks for the update

Very nice. What amps did you use? I think you need to vacuum your car. 8^)

2.5-inch mounting depth
13.5-inch diameter
Only needs 0.8-sqft of box
Rave reviews...

Oh my. The price, too…

https://www.amazon.com/13TW5V2-4-Audio-4-Oh...8593NJZKYNTBWMX

Dammit Pete, you got me excited when I saw it was a JL Audio sub. The first one I bought for my project was an 8" JL Audio can that sub sounded NICE. Unfortunately just a tad too deep for the footwell space so I had to exchange it for a sub that is okay but not as good as the JL. That price is a little rich for my blood though.

Right there with you on the price. Yikes. And it looks heaaaavy too. I'd love to have great bass, but $600-700 and 20+ pounds (as much as my whole system, if not more) is probably going to cross that one off my list…as beautiful a piece of engineering as it looks to be.

JL makes good gear.

They sure do. I'm really impressed with the quality of the parts. At a consumer level (short of audiophile stuff, in other words) it's the best I've seen by far.

And we 914 people have a wacky way of looking at parts pricing. I just paid $400~ for a pair of new exterior door handles—low-tech parts for which the styling, engineering, and tooling was paid for a long time ago—but hesitate when considering a beautifully made sub that would potentially solve a space issue. Decidedly so-so Bose gear in a new Boxster is $990 over the anemic standard sound system, while Burmester is $4,690. So maybe I'll save a little longer over getting a normal eight-inch sub. Question is whether Mark's box would accept something like this thing, and offer 0.8 sqft in volume. Weight will be a consideration, though...

Bigger takeaway for me is that, more often than not, we are beyond lucky to have the choices we do. LED headlights for $300~, or less? The upcharge for LEDs over the standard bi-xenons on a new 718 Boxster? $1,180—or $2,140 on a 718 Spyder, for some reason. Granted, 718 LEDs are superior, and dynamic too, but…

It's frankly amazing what is available for these cars five decades after they were built—whether it's from Porsche AG, 914Rubber, Spokeworks, 914-6werkshop, Tangerine Racing, Vintage LEDs, etc or any number of "non-914" suppliers.

I noticed they also have a shallow mount 10" at about half the weight and price but double the depth. https://www.amazon.com/10TW1-4-Audio-300W-4...1076&sr=8-4

Just the perfect kit to whip out to play a bit of Aerosmith.

Nice find!

10" 4-ohm subwoofer mica-filled polypropylene injection-molded cone with rubber surround
power range: 75-300 watts RMS peak power handling: 600 watts
top-mount depth: 4-3/8"
weight: 11 pounds
sealed box volume: 0.35 cubic feet
ported box volume: 0.625 cubic feet black steel mesh grille

$272

Now, if it works in the footwell box @914Rubber we might just have an ultimate setup for the 914.

@Mikey914 What's the latest?

Need to get back on this it's simple enough. Just haven't had the time lately. I'll follow up this next week as we can easily do these
Mark

You say that for everything.... then a half year goes by.... then another....

@Mikey914 Any progress to report? No worries if not, but I need to get my sub mounted in a box soon so might have to take a stab at a DIY solution. However, if these will truly be ready soon, I'll wait.

I've been sidetracked. I'd like to say we can do it in the next 8 weeks but that might be pushing it.
Mark

If I recall that correctly, there is a difference between the "early" (70-71) and the later foam blocks in the footwell?
I am looking for an stereo upgrade, too and the "foam block" solution sounds good to me.
I checked on my ´71 and there is only a relatively small foam block. Any comments on this are greatly appreciated.

Arno

It has been so long since I had an early MY 914 that I don't remember what the foam looked like other than the foot well was deeper and used the moveable foot rest. However, the bulkhead parts did not change so a subwoofer box shaped like the late model foam piece should still pop right into an older car. The only difference being that your floor carpet or mat will run up onto the box because it is cut longer than the late pattern. I have the 50 year anniversary mats that are cut to the early model pattern in my 73 and do mind that the passenger side runs long.

This might be a good excuse to pester Mark about the status of these boxes again @Mikey914

Yes I need to be poked on this. Need to finish the tool for it.
Currently side tracked trying to finish getting car ready for WCR, as well as the WAS top for Jim. The 1st one of new production. As well as finishing up the latch rebuild kit and the new covers. Making good progress and will have at least 2 of these done this week.

Mark

http://www.914world.com/bbs2/index.php?sho...7620&st=300

Take a look at how Eric at PMB worked out the sub in my 1970 MY 6. 4 will be the same. All is custom

Bob B

http://www.914world.com/bbs2/index.php?sho...7620&st=300

Take a look at how Eric at PMB worked out the sub in my 1970 MY 6. 4 will be the same. All is custom

Bob B
Click to view attachment

Hey Mark @Mikey914 - just another friendly nudge on these.

Nice product. Just remember to reverse the phase at hook up.

It’s fun to see my old subwoofer still kicking around in threads all these years later. I wonder where this thing even is now, I got the impression the guy that bought my car ripped out all the “unnecessary frills”. I had built a few different subs for my teeters over the years and this one was the best of them.

Seems to be some great Knowledge here, so I’m hoping I can learn something.

I am planning to build a box, or two separate boxes, to place two 8 inch subwoofers behind the front seats, on the floor of my 1984 911.
I have seen an older fiberglass box that is no longer produced, and a few other pictures.

This is for subs.
8 inch pair
One behind each seat
Separate amp for the subs

1) does a sub box need to be ported for air to escape?
2) size of enclosure for 8 inch? What if it’s too small?
3) same amp fir two subs?
4) same box fir two subs, or separate?
I have another amp that powers both door speakers, both tweeters, and rear speakers
I currently have a single 12 in sub in the front trunk I want to remove so I actually use the front trunk.

Advice?

Watch youtube. This guy in particular. CarAudioFabrication

Too much to try to explain here.

@Mikey914 any progress on the subwoofer boxes?

Brent - I did "your" stereo install - same amp and location/method as well as some new Alpine 6-1/2's replacing the older Blau's. Sounds good but holding off on a sub even tho I have George's pre-cut panel ready to go. I'm thinking a sealed box would be best....

Good plan. I made a panel to mount the sub in as a temporary measure. To be honest, I think the bass is worse with that setup than if I had no sub at all. I'm going to see if I can figure out a way to make the panel seal tightly against the bulkhead to form a sealed compartment. If that doesn't work, I may just disconnect my sub until a 914R box is available or I have time and $ to make one myself. To do it right will require making a mold so I'd need to make enough to sell a few to recoup costs. Doesn't make much sense to do that with a 914R unit in the works. I need to do something though. I need my tunes!

Couldn't a small sub box be made to fit where the foam kick panel is in the passenger foot well?

Yup - that's exactly what we're talking about....it just needs to be made!

They have been about "six weeks out" for over two years now.

Honestly I had been pushing forward an the door panels, the dash tops the side front pillars and the exhaust. The resins cost has spiked and is actually starting to stabilize. I have the fiberglass bumper top in front of them and they are about to be released.
Mark

Thanks Mark - we know you're busy and always bringing something new to the market - just keeping this in line!