[BMW DIY Guy]

I hope everyone is having a fantastic, week and I am excited to share my latest video! I have been working through installing SoundSkins Global products into my BMW M2C, to reduce road noise and improve the already amazing audio upgrades from BimmerTech.

With all of the sound mat work in the car, I wanted to provide a real concrete follow up on the results of those changes. Keep in mind that I have worked through essentially stage 1-3 of updates to my M2C.

Stage 1 wouldn't change sound floor levels so isn't represented in this video specifically. It absolutely though did make a difference in the sound quality of my door mids. They were more pronounced and richer in sound quality.

Stage 2 did make quite a bit of road noise difference and also continued to improve sound quality of the audio from the door speakers.

Stage 3 is the full meal deal, looking to go after road noise, but also with the underseat subs, insulate them away from the metal floor as well.

So with that, I took measurements at OEM, stage 2 and full stage 3 to show the real world effect of adding materials like this to your car.

The preview is I am super impressed and REALLY glad I did it. Check out the video for actual results and samples, but the instrumentation does show very positive results.

If you find your car a little too noisy, or you want to dramatically improve your audio quality, this is a fantastic way to do so.

[Billfitz]

Your results are probably better than you thought. The meter you used measures dBA. dBA doesn't measure low frequencies, only midrange. You need a meter that measures dbC to measure the full frequency range of human hearing.

A personal anecdote: A large outdoor concert venue near me was getting major complaints about neighborhood noise bleed, especially in the bass. They hired an industrial noise control company to analyze and fix the problem. One year and $50k later, which included installation of a metering system that was supposed to warn that the levels were too high, the complaints were worse, to the point that the town was ready to shut them down. They asked me to come by and see if I could help. It took me five minutes to identify the problem with their metering system. It was measuring dBA. The problem bass frequencies were being read 20 to 40dB lower than actual. The industrial noise company they hired used dBA, because that's what OSHA uses for industrial noise standards. They didn't know that dBA is never used in music applications.

[BMW DIY Guy]

Originally Posted by Billfitz

Your results are probably better than you thought. The meter you used measures dBA. dBA doesn't measure low frequencies, only midrange. You need a meter that measures dbC to measure the full frequency range of human hearing.

A personal anecdote: A large outdoor concert venue near me was getting major complaints about neighborhood noise bleed, especially in the bass. They hired an industrial noise control company to analyze and fix the problem. One year and $50k later, which included installation of a metering system that was supposed to warn that the levels were too high, the complaints were worse, to the point that the town was ready to shut them down. They asked me to come by and see if I could help. It took me five minutes to identify the problem with their metering system. It was measuring dBA. The problem bass frequencies were being read 20 to 40dB lower than actual. The industrial noise company they hired used dBA, because that's what OSHA uses for industrial noise standards. They didn't know that dBA is never used in music applications.

Awesome info my friend thank you, and excellent advice! You are right on a better meter for sure, and used what I could get my hands on quickly honestly. I was glad to have it, but certainly could have also used much broader spectrum, or more sophisticated meters as well.

You are right, that the results were significantly better than I expected as well. Speakers are SO much cleaner in sound quality and overall road noise is down audibly.

Great feedback, thank you!