ddaudi

I've been reading many threads about upgrading speakers and amps in the 991. I learned that the 991.1 with the base audio system (Sound Package Plus) has an "ASK" 7ch amplifier under the passenger seat. Installing an upgraded digital amp with tunable crossovers and 8ch can be done at that location and all (or most) of the needed wiring is accessible there.

I have a 2017 991.2 and I understand there is no amp under the passenger seat; instead the amp is built into the dash unit. I'm guessing there is still room under the passenger seat to install an amp but the signal and speaker wires would not be accessible there.
Can anyone tell me what would be needed to install an amp in a 991.2 with the base audio system? Install under the passenger seat with lots of rewiring of signal and speaker wires? Is there another location where the wiring would be easier? I'm wondering if this is something I can take on myself or if I will need to use a pro installer.

isugoo

I'm not sure on the ASK but Bose and Burmester have amps under passenger seats.
And PCM headhunt is same for every sound options so I'm thinking it may still be under the passenger seat....

ddaudi

I have the Sound Package Plus (SP+) and have read the amp for that is now in the head unit. Many have indicated that if you are going to upgrade, its best/easiest to start with the base system vs Bose.
I'm wondering if the head unit has any line outs or whether I'd have to access audio via the speaker outputs, run those signals via wires to under the seat, extend all the speaker wires from the head location to run under the seat. Hoping someone has added an amp to a 991.2 with SP+ and can describe how it was done.

Barnaby

Not sure if this is the same but this is for it is for a 2015 base radio..... https://www.diymobileaudio.com/threa...arrera.415081/

isugoo

I had no idea. Thanks for letting us know. At least for your speaker upgrade, checkout Rennspec.com for their speaker/harness/adapter options. They have amazing quality products.

PTS-BRG

I had a Bose system and changed the amp. Best decision ever. You can fit a JL Vxi amp under the passenger seat or the Mosconi. I dont know any other amp that can fit in the space under the seat with 8 channels.

ducktails

I have a .2 (2019) with the base audio. FWIW I got a Musicar NW Stage 3 kit and had a local shop do the install. The amp they installed is indeed under the passenger seat, and when talking me through the installation they didn't take my dash out or do anything too significant with the wiring; it's supposedly plug and play.

Edit: from @12v Nick "In the 991.2, the base stereo has no amplifier and instead uses the powered outputs from the in-dash nav system to driver the speakers ... we can use those analog outputs from the radio and send them directly into our new amplifier/sound processor."

Laszlo_Laz

Hello, was the amp swap plug and play or much more involved? I’m very interested in doing this.

Did you upgrade any of your speakers? If so, any tips on sizes?

Thank you in advance.

PTS-BRG

Laszlo: The answer is its complicated.

The speakers need to match the OHM's of the amp. The amp can be plug and play if you have a base system. If you have a BOSE system then you need a NAVTV box to deal with the fiber optics.
JL and Mosconi amps both fit under the seat.

Laszlo_Laz

Thank you.

I’ll need to do some more research on the NAVTV but understand it conceptually.

My thought as stage 1 of 2 is replace the amp first as I’m assuming the low wattage from the Bose amp is 75% of the problem.

Then go stage 2 with better speakers down the road.

When I was younger I’ve amplified so-so speakers and it made a huge difference.

And this amp you recommended is fully compatible for the car.

Thanks again.

PTS-BRG

It’s a two pronged problem. The Bose speakers are garbage and so is the amp. If you change the amp then your weak point is the speakers. Change the speakers and the underpowered, inefficient amp can’t power them. The only cheap upgrade is the tweeters which don’t need much power and can still use the Bose amp. Gotta change everything.

12v Nick

Sorry I'm a little late to the punch with this thread. It somehow slipped my radar.

Clarification on Sound Package Plus in the 991.2 — No external amplifier. All 8 speakers are powered by the PCM on 6 discreet channels(the midrange and tweeters in the front share one powered channel per side). The location for an amplifier DOES still exists under the passenger seat. You will need to run signal input & output as well as power & ground wiring into the cavity under the seat to add an amplifier. You'll also need to run wiring direct to each tweeter if you want to run all eight speakers on independent channels.

This is actually not a difficult task when you have all of the tools to make the job as painless as possible. Yes, I'm talking about our Musicar Plug-n-Play solutions for this platform. I think the Stage Two system we've designed is exactly what you're looking for and it improves the sound quality significantly without modifying the car in any way. Total installation time is about 4-6 hours(depending on skill level) and can be done as a DIY project. Here's a great example of the same system in a 718 GT4:

https://rennlist.com/forums/718-gts-...l-718-gt4.html

The 718 is identical to the 991.2 in this situation sans the tweeter mounting. Amplifier and installation is 1:1. I'm a bit biased, but for the price you'd be hard-pressed to find a better solution with less headache. For a more genuine review, THIS POST is the owner of that car chiming in on his experience.

EDIT: Another post in the same thread from a Stage Two Sound Package Plus owner: https://rennlist.com/forums/718-gts-...l#post17738521

There's more info in our (Now Closed) group buy thread here: https://rennlist.com/forums/991/1281...for-991-a.html

Hope that helps!

—Nick

Laszlo_Laz

Thanks, Nick.

Do you know when you’ll have the stage 3 in stock again for 991.2 Bose?

It seems like your solution is the best solution.

I love taking on a good project but piece-mealing the system may not work for me. Too experimental.

12v Nick

I'm a bit biased but I agree with your sentiment on piece-mealing/experimenting — it can be fun to build a system from scratch, but when the final sound isn't right you have no solid recourse.

All of our kits are built-to-order, and we have raw materials to build a Stage Three Bose right now. Lead time in the queue is about 2-3 weeks for build and ship, at most.