Rear Speakers for a 1978 SC?

[silverlock]

Bought some RetroSound R-463N 4x6 speakers from Crutchfield (https://www.crutchfield.com/S-TM10KFGh9l1/p_068R463N/RetroSound-R-463N.html) after some research here and their fit guide, which is usually good.

Unfortunately they don’t fit: they are plenty shallow but none of the mounting holes are even close, and the mounting frame they come with doesn’t have any holes that align nor is it wide enough for me to Dremel out.

Open to suggestions & recommendations. I don’t need something amazing, just solid 4 Ohm 4x6’s will do. Driving them off a PCCM.

Grey = OE; Black = RetroSound.

[PeteKz]

Speaker sizes are "nominal" not exact, unfortunately. The ones you bought are significantly smaller than the originals. You might need 5''x7" instead of 4"x6". Maybe even a low profile 6"x9". Call back Crutchfield and tell them what problem you're having. I'm sure they have a larger set that will fit close enough to make work.

[silverlock]

Originally Posted by PeteKz

Speaker sizes are "nominal" not exact, unfortunately. The ones you bought are significantly smaller than the originals. You might need 5''x7" instead of 4"x6". Maybe even a low profile 6"x9". Call back Crutchfield and tell them what problem you're having. I'm sure they have a larger set that will fit close enough to make work.

I think you’re right about 5x7” - the P/N on the existing Blaupunkt’s is a 5x7: https://forums.pelicanparts.com/porsche-911-used-parts-sale-wanted/790291-blaupunkt-5x7-germany.html

[silverlock]

After a chat with Crutchfield I have a pair of Kenwood 5x7’s (shallow as I can get) and a couple of sheets of their custom ABS bracket templates in case I need to fab up mounts against the factory mounting bolts.

https://www.crutchfield.com/p_113C5796PS/Kenwood-KFC-C5796PS.html?tp=93

Will report back when they arrive.

[30westrob]

Looking forward to your findings, as my 81SC uses the same speaker. Rob

[silverlock]

OK, update after installing the Kenwood 5x7’s:

* They fit!
* They align with the existing fasteners, but the metal frame on the speaker ever-so-slightly interferes with the “corner” (bend) of the rear shelf. This means there’s a bit of a gap between the speaker frame and the underside of the shelf, which means the shelf sits just a little bit higher. It’s * really hard to tell: the four screws on the front of the shelf all line up, it just sits about 1/8” higher.
* I’m going to take them back out next weekend and remove a bit of material with the Dremel to improve the clearance.

In an ideal world there would be 5x7’s that are <= 2” deep but I’ve yet to find a pair, and manufacturer measurements aren’t always reliable.

In the photos below you can see they don’t quite sit flush. If they can sit flush it’ll be perfect.

[Anjizkit]

Hey. Are you installing the speaker form underneath the shelf? Mine were sitting on top of my self. Maybe mine are wrong but that’s what they were when I took mine apart. Mmmm.


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[silverlock]

Originally Posted by Anjizkit

Hey. Are you installing the speaker form underneath the shelf? Mine were sitting on top of my self. Maybe mine are wrong but that’s what they were when I took mine apart. Mmmm.

The original Blaupunkt’s were installed from below. The top of my rear shelf is perforated: there are no grills.

[mikesarge]

Thanks for breaking trail on this- just ordered a set of the Kenwoods, looking forward to some (at least) slightly improved sound!

[creaturecat]

Polk Audio makes a decent 5 x 7

[Anjizkit]

Originally Posted by silverlock

The original Blaupunkt’s were installed from below. The top of my rear shelf is perforated: there are no grills.

Oh interesting. Can you post a pic of your rear shelf.


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[PeteKz]

I would top mount hem and cut out the rear shelf perforated part. That has to absorb a lot of the high frequencies.

[silverlock]

Originally Posted by Anjizkit

Oh interesting. Can you post a pic of your rear shelf.

[Anjizkit]

Originally Posted by silverlock

That looks super nice


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[Mark Salvetti]

In this thread, someone used Infinity Kappa 64cfx 4"x6" plate speakers for the same undermount install: New Rear Shelf - Replacement Speakers?

According to Crutchfield, the undermount depth is just 2-3/16". https://www.crutchfield.com/S-Z3IIoLovm48/p_108K64CFX/Infinity-Kappa-64cfx.html But I also see that they are NLA there. Amazon still has them for $120.

Crutchfield does have the similar Infinity Kappa 463XF, they are more expensive but the undermount depth is even less (2-1/8").

Mark