12v Nick

Yesterday we had a client drive three hours from the Seattle area to have us install a Stage One tweeter upgrade and acoustically treat the floorboard while it was here. Thought I would share some photos of the process for anyone interested in what it takes to do something like this!





The product we're using is the Musicar Stage One v2 tweeter upgrade and three tubes of SoundShield PRO.







STEP ONE — Removal of seats, interior trim and finally, carpet.











STEP TWO — Clean all surfaces, cut SoundShield to fit and apply. It's self-adhesive but needs to be worked into the compound curves of the floorpan. If it's not making good contact it will never be optimally effective.



















STEP THREE — Once we've got the media properly applied to every surface that doesn't interfere with any mounting or modules, we can reinstall the interior.



TWEETER INSTALL — This has been outlined in other threads time and time again, but the first step is to remove the air vents to gain access to the factory dash grille clips, remove the grilles, disconnect the tweeters and set aside.





Once we have the factory tweeters out of the way we can install the u-nut hardware, connect the new tweeters and bolt them into place.













That's pretty much it. Once we have the tweeters in and tested, the new Burmester version grilles get snapped into place and the project is done! The owner made the three hour drive back last night and said the difference was well worth the investment. He'll actually be coming back next week for us to address some major issues with the audio upgrade that was done up in Seattle when the PCM was replaced. I'll snap more photos and share some info when it's back!

P991GTS

Very nicely done.

quattroboy

@12v Nick I'm interested in the effectiveness of the sound treatment on the floor versus the doors. Did you do any objective sound level measurements before and after.

If not, was there a subjective noise reduction with the floor treatment. The reason I ask is I'm trying to decide what is the best way to reduce road noise.

BTW, I'm a happy customer of your tweeter upgrade!

Tier1Terrier

This is cool and thanks for posting.

12v Nick

I've tried running objective measurements on these types of projects in the past, but it's really difficult to extract any useful information without having a controlled testing environment like a race track or closed road course. Otherwise conditions are just too variable to gauge results on paper. That said, there are certainly subjective results and they're great. The doors make the biggest impact on road noise(and also help your door woofers sound better) but this car had already received door treatment, so we worked on the next most important area — the floorboard.

The owner got a great chance to evaluate the difference since they drove 3hr down and another 3hr back home the same day. Verbatim, the response from that was "After testing the job on the drive back, it seems good!"

devtec

Beautiful. Thank you, Nick!

911Raider

I have put sound deadening on my doors, but not the floorboards. I was wondering if putting it on the exposed metal behind (hidden by carpet) the seat where the rear fusebox would help much?

12v Nick

We've done that on past projects and it hasn't been much of an ROI. It can quiet down a little of the engine noise, but with the symposer in the 991 it's a bit of a futile effort. Doesn't hurt though!

bsitebsitebsite

I’m the owner of this vehicle and thanks again Nick for the awesome work on it!

I actually have some data before and after the job. I tested by coasting at 70mph with cruise control on the same stretch of road and using a sound meter app on my phone and from baseline (when i first got the car a few months ago) to now I went from an average of ~85.5dB to about ~84.5dB

The audio frequency average remained the same but p90 went from 107Hz to 96Hz which i guess implies less higher frequency noises in the cabin?

All in all, this is pretty rough because there’s a lot of factors like outside temp, tire temp, amount of wind etc etc but thought it was a fun exercise to try to quantify this!

911Raider

I did my doors only and did better than that, subjectively, of course. That does not sound correct. I used Dynamatt but there is a noticeable difference. I can’t imagine having the floorboards done didn’t produce better results than you are presenting here.

Levy

outstanding post. love the upgrade. when i eventually upgrade from my S too a TTS (my keeper/grail 911), i'll be doing the same or something very similar.

thx for posting!

spyderbret

Nick did my upgrade back in 2019 and adding the sound deadening in the doors made a big difference for me. I did upgrade the door speakers and amp at the time vs just tweeters so the sound difference was, and still is, incredible. Nick knows his stuff!

12v Nick

Hey, I recognize the back of that head! Only from photos like this, of course

That was a fun install. I always love traveling for on-location jobs — Thanks for the opportunity to do that for you!

james280

Wow - that looked like a lot of work for a 1dB improvement.

bsitebsitebsite

Subjectively, it was a pretty big difference for sure. dB is a logarithmic scale so if the base dB is high, then a 1dB difference can be significant still. The biggest gains I've found were on really rough pavements, I think the variance in noise between different pavement types is much lower as well so that's another plus