Since I don't have much else to do that day, I am going to enter the Vision's dB Drag here. Since I don't have any thing else to enter with I am going to use the wifes '86 VW Cabrio. It has a single 12" Infinity Reference getting about 200 watts RMS, in a ported box tuned to 32 Hz. What frequency should I start with since I have no way of doing any testing before the event. What effect will all the pressure loss (air leakage) because of the convertable top have on frequency? Up or down or does anyone know?

Try a higher frequency. Usually a 40-55 is what I use. 32 just seems too low. Somebody in town must have a RTA that they can test you out on.

Or before the show ask them to run a pink noise so you can see your highest frequency.

32 is more geared towards the SQ department, and we all know that SQ is for the birds ;)

You will peak higher than 32, so why not start there. Just start at 32 and go up from there.

And as far as it being a convertible...running 200 watts, you wont notice a huge huge difference. Now a convertible is a no no for a pure SPL vehicle, but just for the local show you will be fine.

I wish you good luck at the show, and I will see ya there.

Shawn

Giv'er with something around 50hz. Hell, for your first run (qualifying) do a sweep of some sort. There is a graph at the bottom of the termlab that tells you which note was highest.
(Not the most efficient way to do it considering you're on battery power, but I don't see that amp killing your battery too quickly)

OH... I'd also sit in the car for the run if I were you. In dbDrags you are allowed to sit in so long as your score doesn't go above 140. I'm pretty sure you won't be due to the top, so it's just a lot easier than messing with a remote.

Your score will drop dramatically due to the convertible top.

If you're just there for fun though, who really cares? [img]graemlins/thumb.gif[/img]

Basically I am there just to fill space [img]graemlins/thumb.gif[/img] as there is no SQ at this show AFAIK. The box is tuned to 32, because the car is an everyday driver, and not a one note wonder. I guess I will just get someone to watch the meter for me during the first qualifying and hope I get into the rounds, I am guessing street A is where I will be.

Yeah, you'll be in Street A.

If you ask the guy working the mic to keep and eye open for you I'm sure he'll be able to tell you what frequency.