Need Sound Advice

Hello fellow 996 aficionados, Recently I've removed the entire interior of my highly modified 1999 C2 for an interior color change and rear seat delete. While I was in there I've added about eleven pounds of Kilmat soundproofing aft of the front seats and intend on upgrading the stereo speakers, amp and adding a subwoofer. The car came highly modified, including the stereo. It's a non-Bose, non-factory subwoofer car and one of the previous owner has removed the original stereo, bypassed the factory amp (appears to me) and has four wired aftermarket in the doors and rear quarters directly to the Atoto head unit. Not sure if the factory amp works or not but I imagine it was bypassed for a reason. The new doorcards are from a GT3 so pockets, not speakers. Will move the door speakers to the dash. I know nothing about sound or stereos but I like the Atoto A6. It's fast: boots very quickly and the backup camera is instantaneous. There will be absolutely no plan to return this car to anything close to stock. So here are my questions: Should I add an amp? Where? Wires to use? What sub should I use? Plenty of room behind the seats & roll cage Should I get a self-contained amp like a Bazooka? What wires? Should I keep the aftermarket speakers (RockfordFosgate Punch P142 30wattRMS 4ohm? Is that rear quarter insulation factory Porsche? It's applied with double sided masking tape. Should I remove and put more Kilmat soundproofing there? Thanks in advance, please see photos below: Atoto A6 head unit rear ​​​​​​​ Sound proofing going in the rear area. Maybe 10-11 pounds. Is this a good speaker for a 996? Is this Porsche insulation?

Yea that looks to be factory insulation / soundproofing. I think you will find that the best bang for buck sound deadening will be on that rear deck as it looks you have focused efforts there. Less is more on the dynamat type solutions. I did a complete sound system refurb on my 04’ 996 coupe ( had 6 factory speakers and most amp). Happy to help of you have any questions on the amp bypass and options there. I have tried multiple combos on adapters , factory setups with mods and total rip and replace….

On the speaker question……. I went with some JBL’s off of Amazon for the dash and rears and stuck with factory subs in the doors. Note all the factory speakers are very low ohm. The answer depends on the amp driving them or if you are doing a factory amp re use via adapter.

This thread is of great interest to me, and think my questions will help and not hijack the thread. I�m ready to rip out the base factory Bose junk and put in six speakers, a double din, and an amp where the CD changer currently sits. I would like to keep it under $1,000 so I was thinking of the following but would love to hear suggestions. - Sony double DIN (chose this for the volume ****) - 4 Alpine speakers / amp (to stay within budget) - 2 bass speakers for the door (no idea that to use)

Man I guess I am the only one here that find the Bose speakers perfectly fine in this tiny cabin.

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I don�t disagree. On my 03 996tt , it has the Bose package. For that car I used an adapter to leverage the existing amp and speakers. A bergville fx harness was used so nothing was cut. It has the continental unit with CD player and USB port and sound is fantastic. I also have done another setup where an isimple unit piggybacks the cdr23 and that works just fine too. Depends of you want it all original looking or not.

My .02 on this... Because of the MOST system the only thing I would do is completely replace the head unit, amp, ALL speakers and replace them with a matched up/proven to work awesome units, everything! You can re-use the wiring...

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See, this is why I asked. Thought provoking comments�. 1. I don�t think I have the MOST system. Just the basic Bose. Could I get the Sony double DIN head unit and use the bergville fx harness to preserve the speakers and the factory amp?

Thank you for all of the thoughtful responses. I don�t have Bose or MOST and have no ambition of going back to original. The new door cards are off a GT3 so no subs or speakers in the doors (the old six speaker system had subs in the doors?). The rear seats aren�t going back in (GT3 carpet) but there will be a half cage (DAS sport) to which an amp or self-contained subwoofer can be bolted. Do I want it loud? The car is loud so, yes loud, but more importantly clear. I�ve never really been an audiophile but my �12 Cayenne has Burmeister and damn if I didn�t get used to that. The car is 22-23 yo, modified with some questionable choices (found the rear speaker secured to just the insulation w drywall screws) so I�m wondering if I should rewire the speakers while I�ve got it all apart. As much as I would prefer buttons in conjunction with my double-Dinn, I like the Atoto head unit. -do need an amp? -should it go in the frunk? -what amp? -are the RF Punch P142 speakers worth using? -what gauge wiring should I get? I know nothing, thanks for all the advice. You Tube

Any updates on this thread? The factory dash speakers are deteriorated, the new door cards are from a GT3 (no speakers/subs), the factory head unit is long gone, I don't have Bose or MOST and the factory amp is bypassed-presumably dead. The rear quarter speakers are the RF Punch 142s (haphazardly installed by a p.o.) and the head unit is an Atoto A6 Pro, which I like and have just ordered a CarPlay kit and a remote volume ****. I'd like to have decent sound by keeping the RF punch quarter speakers, add a self-contained sub somewhere in the rear, replace the dash speakers and? maybe a 5-channel amp. If anyone has a better solution, I'm very interested in hearing it. If the advice is return to stock, well that's not going to happen.

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My dash speakers (Nokias) are deteriorated, the door speakers/subs are removed for the new GT3 door cards, the factory head and amp are gone, as are the rear quarters. So.....

The stereo in your car is similar to mine when I got it. The factory stereo was completely eliminated. My car had fairly high-end MB Quart speakers and a Pioneer navigation head unit that was top of the line when it was installed in 2006. But, by the time I bought the car in 2019 it was pretty dated and I could tell the install was not up to my standards so I yanked it all out and started over. I eliminated the door speakers in my car (I too have GT3 door cards waiting to be installed), and I just have the four 4" speakers in the dash and rear to provide the highs and mids. I went with Polk DB-series speakers and I am pleased with them. I built a custom box for the rear deck that houses a single 8" Polk sub as well. I didn't want a lot of bass, and the 8" sub is more than sufficient. I have an Alpine 5-channel amp that powers everything. I wouldn't call it an audiophile system by any means, but it sounds much better than the factory Bose stereo in my old C4S, it was budget friendly, and the sound quality is quite good considering the mids are only 4". If I were to do it again I wouldn't change anything except the Pioneer head unit I chose because I don't like the UI.

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On my 99 996 coupe - I recently put in the following. (Sorry, but it�s easier to just post pics of the boxes. Trying to start my weekend). But first I�ll tell you that a) I could have spent more on speakers and the amp, but I wanted CLEAN sound with quality mids and highs, and decent bass WITHOUT a sub woofer. It turns out I didn�t need to spend more. This set up worked out really, really nicely. b) I reserve the right to add a self-powered Nakamichi (or other)small form factor sub in the frunk at a later date. c) What I ended up with ($2,000 installed) is a really clear, punchy, surprisingly balanced sound. A sub would definitely make this system complete. But I�m just not sure I want to dump another $500 into it yet. This amp is more than enough to run all six speakers. Four 4� on two channels, and two 5 1/4� on the other channel. These speakers in the doors, but with the tweeters mounted inside the dash housings - really helped make the separations jump out in ways I�ve never heard, from musicians I�ve been listening to for 40 years These speakers in the doors and in the rear panels. I didn�t know JL Audio offered a budget speaker line ($99 a pair!) so these were a definite find. Pioneer double DIN with Apple Play. Went with this over Alpine because my car audio guy and his techs urged me to use this one instead. Told me the display would be much better in daylight and it is fantastic. �Some� of the user interface is a little cumbersome but nothing terrible here�s a shot of the amp and the crossovers mounted in the frunk. Pretty simple. Lastly, I don�t work on my cars. This is one reason why. It would make my head spin and I�d screw it up for sure.

Capt. Obvious Thanks for the response. That looks great. How did you design the box? There seems to be a whole science for those things-I've pulled the rear seats and have a half-cage (DAS Sport) to further complicate things. Do you have any photos of how you got the speakers attached to the speaker grills?

MBH911 Thanks for the response. I'd read your thread and posed my question there about mounting those JLA C1-400 speakers to the grill.

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pretty cool. Did you consider any low profile subs that could have fit in the frunk? I�m Only interested in something unseen. Just curious if you have any insight.

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Subwoofers in the frunk would produce good sound inside the passenger cabin?

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in the frunk would probably be far less effective. I don�t know. my guess is it will have to be something that fits behind the passenger seat, maybe mounted vertically against the rear �foot wall� (I made up that term) and facing the seat. There�s a JBL sub that might work. https://www.crutchfield.com/S-itWLFL...kaAg6TEALw_wcB

My plan is to try something similar to a guy on the 911uk forums did�he bolted a Focal powered sub horizontally under the passenger side dash. I can�t find any details but will explore when my car comes out of storage. You can see a bit of it in this pic; he had a leather covered fitted which I won�t bother with. http://www.911uk.com/viewtopic.php?t...asc&start=1020

I like what he did to his back seat area.........makes it useful and ads a bit of storage to a model that doesn't have a lot !

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If you aren't competing in a sound quality or SPL competition and just want a good sounding box, it's not too difficult. The most important factors are that the box is airtight, rigid (thick enough material), and the internal volume is correct for the sub. In the case of my sub, it requires a .75 cubic foot box. I achieved that by playing with dimensions until I had the volume I needed. Putting the sub in the frunk works on air cooled cars because of how they are constructed. There is actually quite a bit of space between the frunk and cabin on 996s, and thus no where for the sound to travel between the two. I looked into making some sort of port between the frunk and cab of my car, but I couldn't bring myself to cut up the car in that way, nor could I find a good spot to do it.

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Hello, I'am hoping to reach out to you. I was replacing my rear speakers but the depth is very shallow due to the factory sound insulation. Would cutting a hole and inserting the speakers have an adverse effect in the music sound? or would it harm the car? Sorry for the newbie question but I am stuck in the middle of installation. Any response is appriciated. thanx in advance. h.

Hello, I'am hoping to reach out to you. I was replacing my rear speakers but the depth is very shallow due to the factory sound insulation. Would cutting a hole and inserting the speakers have an adverse effect in the music sound? or would it harm the car? Sorry for the newbie question but I am stuck in the middle of installation. Any response is appreciated. thanx in advance. h.

I'm going to suggest, without any real knowledge that the sound insulation is to keep sound out, not to protect the speakers. If you cut out just enough to insert the speakers, you should be OK. But you might make sure there is enough space if you cut it out. You can probe the space available with a pocket knife.