Building a high-end audio system for top sound quality in the Boxster

[newBgeek]

My competition car scored 116db in the SPL tests which was on the low side since I was tuned for sound quality. The average was about 118-119 with the loudest cars hitting 125. I'm running the same power in my Boxster and from general impressions, I'm probably hitting very close to the same levels.

With the top down and the windows up, the Boxster cabin is an amazingly quiet and refined place to be, and you can enjoy your tunes at moderate listening levels, and still be able to have a conversation with your passenger or be able to hear sirens. On a busy freeway, the noise from other vehicles becomes a problem and you really need to crank it to overcome the noise, so it's nice to have that flexibility.

Also, the decibel scale is logarithmic, so every 10db gain has 10X the sound intensity, so a 30db gain actually has 1000 times more sound intensity which qualifies as hi-fi in my book.

While I don't think it's ever a good idea for a driver to wear headphones, I'm also a headphone junkie and got my start in real hi-fi with a pair of Sennheiser HD430 headphones which were an amazing headphone in it's day and still one of my favorites to this day. Headphones are great to use as a reference sound due to their very low distortion levels and high quality per dollar spent. A very good reference headphone to use to setup car audio systems is the AudioTechnica ATH-M50x. They are very clean with strong, extended bass that is slightly on the heavy side, but is what you want in a car environment. If you can setup a car audio system to sound like these, you have done very well.

[alm001]

Originally Posted by newBgeek

Also, the decibel scale is logarithmic, so every 10db gain has 10X the sound intensity, so a 30db gain actually has 1000 times more sound intensity which qualifies as hi-fi in my book.

While this information is not incorrect, I believe you misunderstood Topless's comment regarding dynamic range.

With an 80db noise floor (his example, not mine. But I can measure it next time I take the car out) you lose a lot of information because you only have a 30db "window"

From a quick search, here are the dynamic range capabilities of various media;
78 RPM Phonograph = 40 dB quickly reduced to 30 dB and worse due to wear
Compact Cassette = 50 dB
Digital 16 Bit Audio = 96 dB
24 Bit Audio = 144 dB

So while a snare may measure 116db at your ears, a soft piano key may fall below the 80db floor, and get lost. You can overcome this with equalization and compression, but you end up with stifled dynamics.

Probably not helpful, I just wanted to clear up dynamic range vs max spl.

[newBgeek]

Originally Posted by alm001

While this information is not incorrect, I believe you misunderstood Topless's comment regarding dynamic range.

With an 80db noise floor (his example, not mine. But I can measure it next time I take the car out) you lose a lot of information because you only have a 30db "window"

From a quick search, here are the dynamic range capabilities of various media;
78 RPM Phonograph = 40 dB quickly reduced to 30 dB and worse due to wear
Compact Cassette = 50 dB
Digital 16 Bit Audio = 96 dB
24 Bit Audio = 144 dB

So while a snare may measure 116db at your ears, a soft piano key may fall below the 80db floor, and get lost. You can overcome this with equalization and compression, but you end up with stifled dynamics.

Probably not helpful, I just wanted to clear up dynamic range vs max spl.

Yes, I get what he meant. I was just making the point that 30db is actually a lot more dynamic range than what the numbers might suggest. We want a 90db or greater noise floor in our music source so that we can have absolute silence when the music isn't playing. Gone are the days when we could set our music volume by the noise we hear before the music starts playing! True, we are going to lose some of the nuances of the music due to road noise, especially during quiet music passages, but that is true with any car. Is it still worth doing a decent stereo in the Boxster? If you have a stock or mild aftermarket exhaust, then absolutely. If you have a racing exhaust, it's probably not worthwhile.

Most of us drive the Boxster because it makes us feel special. Sometimes we just want to put our foot in it and hear the song of the engine, which is great. Other times we just want to cruise and turn on some cruising tunes. It's nice to have a sound that is rich, lush, and wraps around you like a warm blanket. It just gives the Boxster that extra-special feeling of refinement.

[alm001]

I agree, always worth it to upgrade the stereo.

I'm making slow progress in my current car, but all my previous cars have had extensive work done.

[Topless]

Yep, most of my audio experience is in pro sound, not car audio so I do have an appreciation for excellent music and and understanding of the relationship between dynamic range and SPL. The other half of this topic not yet discussed is the effect of driving around in a car every day with music at 110-115 db. Hearing damage is pretty certain and once they are gone, they are gone. Choose wisely gents.

https://www.google.com/search?q=osha+spl+chart&ie=UTF-8&oe=UTF-8&hl=en-us&client=safari#imgrc=NADVANC4d8NHeM%3A