Speaker Question: Do JBL GTO 329's fit dash on Pre-Bose Models?

I've seen several threads mentioning the JBL GTO 329's for the 996 dash speakers, but all those discussions have been for the Bose system. Do the JBL 329's also fit the Pre-Bose cars? (my car is model year 2000 if it matters) The reason I ask is because I have the Alpine SPS 410 currently, which are 4" and the JBL's 329's are only 3.5 inch. Also, are the JBL's truly bolt-in? On the Alpine's, I had to modify the speaker basket a bit before they fit. I am considering the JBL's over the Alpines for two reasons: 1) The seemingly great feedback on RL for the JBL's sound quality; and 2) I've had two Alpine's fail so far. The first was replaced under warranty, but now the 2nd one has failed (rattling noise on bass both times). At this point I think I'd rather change to JBL's rather than get another Alpine, particularly if the JBL's sound better. I don't really crank the stereo ever, so not sure why I've had 2 Alpines fail.

<-- POST DELETED --> I thought for a minute that JBL 429's (4") would work instead of 329's (3.5") since I know 4" Alpines fit. Looking more closely at the pictures though, it looks like 429's cannot be mounted from underneath while 329's can mount from underneath because there is a ring around the speakers. Comparison of JBL 429 and Alpine SPS-410 -> https://www.crutchfield.com/S-0Md18X...e-SPS-410.html Specs for JBL 329 -> https://www.crutchfield.com/S-2Tn2M7...BL-GTO329.html Crutchfield indicates that Alpine SPS-410's will fit a 996 with mods (which is true). Crutchfield says that JBL GTO 329's and 429's do not fit a 996 (but it seems like RLers have fitted 328/329's without issue, at least on Bose cars, still not sure about pre-Bose).

I cannot answer your question, but my �99 non-bose setup needs all new speakers as well. I have a JL amp and sub that are waiting patiently.

Here is a post on installing GTO428, https://rennlist.com/forums/996-foru...l#post13963787 . I compared GTO428 and 429 specs on the Harman's website and it seems 429 indeed has slightly larger cut-out diameter, 3-1/2 vs 3-3/4. I have a set of 429s also waiting to be installed, so will have to get on with it before the return expiration date.

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Awesome! Thanks for the feedback. I was afraid I was talking gibberish (of course, it is gibberish unless you happen to have any of these speakers ). Look forward to seeing how your 429 install goes! Is your 996 Bose, or pre-Bose?

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My experience is that you will get a sound pretty big sound improvement from replacing the dash/rear speakers. If you have the HiFi option, the stock mid-bass woofers in the doors are actually pretty good. For whatever reason, the build quality of the factory woofer is much higher than the factory dash/rear speakers. I replaced the door woofers with Tang subs and, while they go deeper than the factory woofers, it's more difficult to get balanced bass and the power of the Tang subs can overwhelm the door enclosure limits (the door can rattle with bass-heavy songs). If I had to do it again, I'd leave the stock woofers and use an external sub to fill out the bass as it sounds like you are doing.

I just pooped open one of the GTO429 boxes and removed dash speakers to size it up. Unfortunately, it looks like it will require trimming the original plastic mounting trim. I initially thought grinding away the inner most "ring", marked with orange but I would have to grind away about half of the outer ring, marked with green. It seems it is largely due to the way outer structure of the speaker is built. 428 has magnet mounted on top without anything covering it but 429 has plastic outer structure covering magnet which makes it bulkier. I think I will order a set of 329s which probably will fit with less surgery.

I am interested to see how this goes. The speakers in my 99 also need to be replaced.

Im also interested to see how it goes, I want to pair new speakers up with the Porsche classic radio. Have everything factory looking.

329s are on their way, should be here tomorrow. I do have Bose with CDR220, and my plan is to update the speakers, add Bluetooth to the factory head unit for the time being, especially since a LARGE of sum of money is being spent on suspension overhaul. I was surprised to find that it is almost impossible to find an aftermarket head unit (Double DIN) with volume ****, Apple Car Play (or proprietary app that effectively can mirror select apps, like Waze) and HD radio. Any suggestion would be (feel free to PM) welcome. Thanks. John

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I had to go back to photos to remember what I did to mount the Alpines, but basically it was to cut off the for mounting tabs so they would fit in the factory speaker basket. I'm not sure how this compares to what you would need to do to get 429's to fit. Looking forward to your feedback on 329's. Factory Dash Speaker (with awesome "100% genuine paper" cone! ) Factory Speaker (from side) Alpine with mounting tabs cut off to fit in factory speaker basket ' Alpine glued into factory basket Mounted alpine before reinstalling (speaker wire harness from Crutchfield)

Just finished mounting 329s to the dash housing as well as rear side panel housings. It was pretty straight forward and definitely easier than the 429s. All you need to to is cut the mounting tabs half way, just so that you can use the remaining plastic tabs to hold it against the frame with screws. I applied some hot glue to make sure it won't come off or rattle. I cut the wires to the Bose tweeters and wrapped with electrical tape. I turned the stereo on to verify sound from all speakers but did not do much listening so cannot say much about the sound quality at the moment. It definitely has more bass as well as clarity, but Bose was actually pretty decent, except for occasional crackle from the right dash speaker. I will get to the 529s tomorrow.

I did mine a month ago, and although I used Focal brand speakers, I had the same issues that I think every speaker option will run into. I ended up buying these custom machined adapter rings from Car Audio Innovations . They're machined to fit the stock speaker grills although you do have to trim the mounting ears off like others have mentioned. You still need a Dremmel to tweak the stock grills but it is mostly for the tweeters.

Replaced Bose woofers in the rear deck with a pair of 529s, which fit without any modification. The mounting ears are plastic so just make sure not to tighten the screws down too much, otherwise they will crack. I spent a few minutes adjusting bass and treble setting (it was set way too high on the treble). I think I left them at 3 on both and sounded very nice, and I prefer the sound in the 996 compared to Bose system in my wife's 2014 Cayenne which may have something to do with the size and shape of the space, I wonder? I will eventually have to replace the door speakers but if I did not already have the speakers, I'd be just as happy with the way they are now.

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Thanks for the feedback. Based on this, I think I am going to order the 329's too replace my failing Alpines rather than getting a replacement set of Apines. My car is "Pre Bose", but seems likely that, if the dash speakers fit in Bose cars, they should fit in pre-Bose (at least I hope).

I'm going to try these on my pre-Bose 996. Does the factory wire harness fit the JBL's, or do you need an adapter?

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I can't speak definitively for the JBL's because I don't have them yet, but I'm pretty sure they don't come with the speaker wiring harness because the connector is specific to Porsche. I know the Alpines definitely did not come with them. The speakers are just two wires, so you can just splice in if need be, but it's a lot cleaner to use the wiring harness. I got my harnesses for the Alpine (which should also fit the JBL's) from Crutchfield. Amazon carries some harnesses, but I didn't see one for Porsche (there was one for VW, but it looks different then Porsche in the picture).

JBLs have the same spade-type fittings so no need to modify wires. You may need to crimp it a bit for snug fit but that's about it, at least on my Bose-equipped car.

On the pre-Bose cars (at least on my MY2000), the harness actually plugs directly into the speakers rather than having the typical male spades you see on most speakers. Actually, the terminals inside the connector look a bit like spades, so you might be able to attach speaker leads, but the cleanest way is to use the harness (shown in the last pic of post #11). The harness helps ensure that the speakers have proper polarity (speakers will work fine connected either way, but you loss bass if they are not both wired with the same polarity because the speakers moving in opposing directions causes the bass soundwaves to be cancelled out). Here is a photo of the back of my original (pre-Bose) speaker that shows where the harness plugs in: Original (Pre-Bose) Speaker

Have you been able to install the GTO329s in the rear speaker baskets? I received mine this weekend and it's not a snug fit. I was told by CAI that their ring adapters will not fit these speakers...

So this thread motivated me to swap my speakers to the 329's. I just cut the basket off the old speakers and noched the speaker cover and the old basket to samwich the 2, 329 speaker tabs. I did not have to cut the tabs. I then hot glued the tabs to secure the speaker. I did have to trim the plastic on the speakers i the rear because they hit the grill. I guess i should have taken a pic . I think my door speakers will here today, got a set of i nfinity KAPPA52.11i nfinity KAPPA52.11i They had a few good reviews and amazon had an open box for half off. they sound pretty good compared to the factory, my system is deffinately not bose on a 2000 c2, but i do have what looks like an factory amp in the frunk. I really want to keep the factory radio because of the clean look but i probably swap out the amp with an adjustable low pass filter.

So i put the infinity speakers in the door. I cant say i would recomend them because they sound a little muddy. Im not sure if its the speakers, factory head unit or the Haas 6x40 amp. Im sure the system really needs an eq. Here r a couple p8cs from the install. The screw pattern is the same, but u need to open up the box slightly for clearence. I just used my knife because i was too lazy to get the dremmel. Hope this helps someone in the future.

Bringing this back to life, has anyone swapped out the factory amp with an aftermarket one? Are there any out there that fit the factory bracket in the frunk? Also, for dash and rear speakers, it sounds like any 3.5" speaker will fit in the factory enclosures with some fiddling, is there anything else out there besides the GTOs that anyone likes?

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I found a link on here last summer, a guy found an amp that would fit and did the whole install himself. So yes it can be done. Its a great write up.

Hey Everyone, I replaced my dash speakers with a set of Polk DB351 3.5" speakers and the passenger side is getting little to no power. When I isolate that speaker, adjust balance and fade to front right, there is only a very faint sound coming from that speaker yet when I do the same for all other speakers they sound loud as expected. I double checked the wiring on both the new speakers and redid it every way possible but always got the same result. Any ideas on where I should check to sort this out?

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Do you have a meter to check resistance? Sounds like a short. You can try swapping the channels to see if the amp is shorted

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That's kind of what I was thinking also, I'll see if I can borrow a meter from somewhere, would it be worth pulling out the stereo and checking the connections there or would it more likely be from the amp? I pulled the amp off and all the wires are tied into a couple big plugs so I'm not sure how to swap channels. There aren't RCA inputs like on an aftermarket amp. My car is non-bose 6 speaker system with CDR-220 stereo and factory frunk amp btw.

I have a 2000 c2 cab. I put polk 4x6 in front and rear. Lots of cutting , replaced door with polk 6.5 added kenwood double din and kenwood 5channel amp in frunk with a kicker 8 inch boxed woofer behind driver seat foot well. Gives me hands free and sounds much better . I had the cr220 and hifi option.

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The basket of the new speaker could be pinched. This would make it sound like it's getting little to no power.