fatty matty

iTrader: (4)

One of our vehicles is a 98 Ford Ranger extended cab. I have a nice Diamond Audio 10 inch sub in a custom ported box that is very flat to around 35 htz. While driving with the windows open I get a lot of nice low bass with plenty of volume. As soon as the windows roll up I can barely hear the bass, especially at lower frequencies. I have no problem with this in our car (not noticeable anyway) because there is more volume in the car for the bas to load (I think that is the term).

My question is - if I beef up my bass by adding subs, say moving to a pair of 10s or 12s, can I ever get more volume at these lower frequencies in this truck or am I limited to what I currently have due to the volume of airspace in the cab?

Thanks in advance.

Ravemeister

iTrader: (36)

On paper, when you double your power, you should get about 3 dB more but, in a car environment, there are too many factors ( space, temperature, etc). The reason you are getting more volume with your window open is because you car becomes a ported enclosure, and you are tuning the box with openeing of the window. Volume is SPL, sound pressure level. If you add speakers AND power, you increase the pressure (volume) within the cabin.

The Tube Doctor

I might be accused of sounding like a broken record, (remember those big black discs?) but you can use LEAP to do a highly accurate simulation of how your enclosure will perform with a given enclosure. (One of many cool techniques Howard Doctor showed me.)

You can define the interior volume of your vehicle as an acoustical filter and accurately model the bass response of your woofer system for any given window opening. The model ends up looking like a serial-loaded bandpass.

I had a similar problem with two sealed 10" woofers in a Benz C-class. With either the windows or trunk open, the bass was great. Not so great with everything closed.

Yes, the sub-box had to be redesigned, but the results were highly satisfactory with no need to add more power or drivers.


When properly calculated, you can achieve up to (or maybe more than)
10 db of room gain (that acouctical filter) versus anechoic.
Most programs yield anechoic data, but LEAP takes things to a higher level.
(pun intended)

If you don't have the means to fork out big bucks for LEAP, try to find someone who's got the program and who knows how to use it.
I'd sooner spend a couple of hundred getting the calculation right (or as close as possible) rather than having to second guess less than optimal results, rip things apart and buy more equipment.

http://www.linearx.com/products/soft...5/LEAP5_01.htm