What actual diameter of grill will the rear speaker recess fit? Polk vs. JL

[ewalberg]

So i've done my share of looking and searching through the forum and there's lots of tasty info, but what i can't find is the diameter of the recess that the rear speakers sit into? i see that many people are fitting the JL vr650-xi's in the back with spacers, but i DON"T want to use spacers because i regularly put the soft top back there and i need something that fits down into the stock recess for the drivers.

ALSO!!!.... I've read people said that the polk DB651s drop straight in with no mods accept perhaps with the supplied adapter ring?, but is that adapter ring an offsetting spacer ring just like i don't want to use? Anybody have any pictures of the DS651's installed back there?

My preference is to use the JL vr600-xi's as they're smaller than the standard vr650's and the VR600's frame is slightly smaller diameter than the Polk DB651s', so maybe it'll also be a drop in? I don't mind removing some foam, and i don't mind opening up the clearance hole diameter (though it's the same as the db651s), i just don't want to have to add spacers becuase of how i use the luggage area.

The JL VR600-xi's have a max outside diameter of Grill at 6.5" and a depth of 2.38"

[Implosion]

My Elise w/ 651s is parked in RWC right now. Want to come by to see?

[ewalberg]

That'd be sweet. I'm heading to RC after work... where you at? (I'll PM you to keep the details off list).


To others, any and all additional info regarding acceptable mounting depths and diameters would be great.


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[Walnuts]

I have DB651s in the rear of my Exige. I had to slot the existing holes for the screws and open the cutout in the panel to fit the speaker frame. It was really easy and looks great when finished. The covers fill the recesses made for the speakers very well. Sorry, not pictures for you though.

[ewalberg]

Walnuts, so you DIDN"T use the mounting rings (which are about .25" or so? Implosion used the mounting rings and just removed the extra tabs on them. it all fit up nicely but the speaker grill wasn't actually down in the recess... it looked like it might not fit down in there, but since you said yours was snug in the recess it sounds like you didn't use the mounting rings, and instead opted to do a little more trimming of plastic for the back side of the speaker?

These are the measurements i see that are different between the two which impact the fit.

Polk: DB651s
Grill height:1.12"
Grill Diameter: 6.85"
Mounting depth: 2.0"
mounting hole diameter: 4.9"

JL VR600-xi
Grill height: .91"
Grill diameter: 6.51"
Mounting Depth: 2.38"
Mounting hole diameter: 5.00"

Based on this i'm thinking the JL vr600-xi's may only need just a little foam removal to clear the magnet (along with a little trimming to the mounting hole and screw holes like the db651's), but that it should exterior wise be a good fit without any spacers. it'll actually sit a little more flush (which helps me with getting the soft top in and out of from behind the seats.

For reference i've fond the only real difference between 651s and 651 is how tall the grill is... the back of the speaker is the same (i checked on this after someone mentioned the db651 also fits.

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[JWA]

Originally Posted by Walnuts

I have DB651s in the rear of my Exige. I had to slot the existing holes for the screws and open the cutout in the panel to fit the speaker frame. It was really easy and looks great when finished. The covers fill the recesses made for the speakers very well. Sorry, not pictures for you though.

Same experience here. No mounting rings needed (or wanted, when you break away the tabs there are rough edges left). I trimmed away an 1/8" or so and made new holes for the screws. Very easy.

[Implosion]

Erik-- I should have written 651's in my original post. I have the full-depth version, not the slim version.

That said, I did dry-fit the grill into the cutout and didn't look like it was going to work. That contributed to my decision not to get into modifying the dense closed cell foam behind the firewall (hello mess).

Good meeting you today. Let me know if you need to drop by again. And apologies if I caused confusion in the model #s. I recall looking at them both, but did not occur to me that pluralizing 651 without an apostraphe is ambiguous in this situation

[stinkyonion]

I have the JL vr650 in the rear. The grill fits to like 1mm inside my v-force harness bar. I couldnt possibly use a spacer. I initially trimmed the foam, then that wasnt enuf, and cut a cylinder all the way to the firewall. It is sloppy looking but so what, hasnt effected anything. Others have said that they noticed a drop in quality if you went all the way to the firewall, but I dont notice anything but improvement over stock. I have seen photos here on lotustalk where people have cut perfect circles all the way to the firewall, like with a laser. I asked chuck risen how this was done, he says patient cutting with an exacto knife. I just kind of cut with a box cutter, which was too thick to do it nicely, but not sure if we really care about the appearance behind the liner.

[...m...]

...i bought the 6501 system first before deciding that i preferred the 5251 installation with OEM trim rings instead, so i have both the 6501 and 5251 component speakers...

...while while the former are the same depth as the 651s and fit just fine, the 5251 are actually deeper and a very tight fit...i had to trim out my rear insulation to make the 5251 drivers work, and they do, but anything deeper would definitely require spacer rings...

[ewalberg]

So i've got the foam at home (i'm going to be installing it if anybody find that believable, but anyway, i noticed that the foam that sits between the back of the magnet and the firewall is really only .25" at maximum... probably a little less... so cutting it out will gain a little clearance, but then you could have the magnet slapping the aluminum at high volumes which might explain some peoples statements of decreased sound quality total removal of the foam separating the magnet from the firewall. Along those lines i found that my car has a big 2" think piece of soft/compressible felt between the magnet and firewall so it seems that both the touring option (with foam) or base car (with this felt) has "something" to keep the magnet from slapping the firewall/bulkhead, so on doing an install i'd make sure they can't come in contact as it certainly wont sound good. Even just a layer of dynamat might help so it's not metal slapping metal.

So ...m... has successfully fit the DB5251 (i'm assuming the DB line), and they're at 2.31" depth but his thinking is that nothing really deeper will fit.

stinkyonion has fit the VR650's which are actually at 2.44", also cutting out all the foam to the firewall.

So with the VR600-xi's are at 2.38" it seems to be in a middle gray zone of possibly fitting, possibly needing spacers. It seems if it needs a spacer a couple rings of pressed poster board might be all that's needed... and that can be cut with fancy scissors. Since the speaker grill is so short i may opt to use and use a tiny bit of spacer to try and keep the foam between the speaker magnet and firewall... hummm... eitherway, it definitely still seems like a viable option.

Thanks for all the feedback guys. Good info.


Oh, side note, Oddly, just like the Polk DB5251 speakers, the JL VR525-xi's are also their deepest speakers so that's not a better option in this case... the vr600-xi's are actually the shallowest... and those are at 2.38" deep.