terry gt

Just upgraded my radio to Alpine cr 138 BT so I have a hands free phone , can plug in my I phone . Sounds great ! lots of power ! See the small mic on the pod ? . The PO installed new speakers and the amp . The speaker on top of the rear quarter panel are missing but you would never know it . This is in my 91GT

Paul Dortkamp

A nice head unit. Amp install is neat. it looks to me like the amp has the big power terminals exposed. The speaker connections have a cover, maybe think of some insulation for the power screws.

hans14914

I will order a set of the SWS 6.5 and see if I can machine an adapter ring to make them work.

I have had a dealer application sitting on my desk for a while for Earthquake. The 10" Dayton I had been using for the Sharkwoofer was recently discontinued, so going to try the 10" SWS to see how that does. Once I have my application in, if anyone needs Earthquake drivers, I am glad to help.

Will get back to people on if they can be fit to the 89+ cars easily. I know they can fit on the 84-88 cars, as my drivers 6.5" have the larger ISO flange, and I can get them to fit. My drivers are not really bass specific though, so would be nice to have these as an alternative to a rear install like Sharkwoofer.

hans14914

Paperwork in place. I am now an Earthquake dealer, and ordered samples today. I will get some adapter plates fabbed up for the 6.5" speakers for use under the factory grills.

Paul Dortkamp

I turned the volume up too far on my subs yesterday and had one sub cone bouncing off the grill, so I am looking forward to an adapter plate. I have another set of stock rear mounting bases and grills ready to go in.

ammonman

Great news Hans. I will most likely be looking to get a set of the SWS 6.5s along with some of your new 89+ grills/mounts and a set of adapter rings to fit the SWS units if everything comes together. Fingers crossed.

Mike

Paul Dortkamp

Following the upgrades I had an obtrusive whistling noise during quiet periods of music. Solution was to fit a filter to the positive feed to the amplifier. Managed to fit it in under the cover on top of the fan control unit. I also tried running new separate earths for the amp and head unit back to the earth point at the top of the CE panel, no real change. I remembered that the noise appeared when I changed the amp and before all the other changes - head unit and Hans door speakers. With the upgrades the whistling noise became more obvious, it increased in volume as the revs went up, so I assume that it is alternator related. I saw in the wiring diagrams a while ago, that the original S4 installation had a choke in the circuit. This was not present in mine.

Tom in Austin

Bump to Hans ... is Earthquake SWS 6.5 a workable solution for post-89 B-pillar speaker replacement? What are your thoughts/conclusions on modifying and re-using the factory 6.5 mountings?

hans14914

Tom,

I dont see any easy way to add to the 89 and newer round grill. The early square grills are not a problem.

The only real solution I have found for the rears on the newer cars is to have a new part injection molded. I can have them made, I just need enough people to commit. I really cant front the cost of tooling another grill, still haven't come close to breaking even on the first run of speakers.

Thanks
Hans

Tom in Austin

BTW, how does the newer round grill and speaker come out? Looks like in two sections but no visible fasteners ... do the two parts snap together?

I feel the need to take one out and look at it ... worst case, assume I can refoam and go with what I have ...

And hardly need be said again, but thanks Hans for all you've done for the community on this ...

ammonman

The grill pops off the face of the mount. The plastic ring of the grill is fragile so be very careful removing them. Use a butter knife or stiff plastic scraper to help pry them off. Once the grill is off there are four screws through the face of the mount that secure it to the quarter panel.

Mike

davek9

Hans I'm interested in these too as my Spare Tire space is being used for another purpose

Sounds like a great solution for Base to match up w/ your door speakers I installed last summer.

Thank you,

Dave

hans14914

Cutting the first batch of test adapters on Sunday for the square grill cars. See how it goess

auzivision

I know of an 87 not too far away with lots of amp that could be used as a mock-up stage

hans14914

I have a working adapter for the Earthquake SWS-6.5 for the early square grill cars. I need to make a couple tweeks to the design to incorporate the speaker hold-down clamps, but apart from that, everything is good to go.

Pics included, both with grill and without so you can see. This sets the driver back so it should not hit the grill under most conditions. This spacer is 3/8" and I may try 1/2", but this is already tight when installed on the quarter panel. The cone is rated at 3/4" forward travel from rest, and so with the domed grill, its close to clearing full extension, but not quite. Hopefully people wouldnt max out the mechanical limit of the drive anyhow, as that never sounds good anyway.

I will try and get revision2 done this week and get pricing out for those interested.

Thanks
Hans