Well after 4 long months of crunching mathematics and trying to make what looked good on paper look good in the real world, My box builder and I finally came up with a box design that allows for interchangeable slot porting. Now most would say why bother you can just use round ports and change the length. Well that sounds good on paper to but round ports tend to whistle thus not sounding as good.
So anyway we came up with a design that basically works like this. First you need to determine the resonant frequency of the car. In this application it was 49hz. So we built the box initially with a program tuned for the maximum output at 49hz. We then went back into the program and retuned it for a snappier cleaner response and tuned it to 35 hz. So basically what we ended up doing is building a port that slides into a larger port. Using the program we were able to keep the length the same and actually just change the cubic volume of the port by sliding a port sleeve into the larger port. And then we put it into real world testing.
Using a small kicker 600.1 kicker amp and a pioneer TS-W3004SPL we first popped a 5 second note at 49hz with the sql port sleeve. Not bad we pegged 136db. Then we removed the sq sleeve port and fired the same 49hz 5 second note and bang like clockwork 138.5db. A sucess although we were hoping for a full 3db increase, that is only likely in a perfect world. Also note that this sub was greatly underpowered when we tested it. It can handle up to 3000 watts peak and is rated for 1000 rms. It can take a full 2000 watt rms without skipping a beat in the spl lanes so we are guesstimating it to hit in the 141-143 db range. I'll post some pics up of the box this week sometime.
Also might add i took it for a sound quality run and the difference between the 2 ports is like night and day. The sound quality port is snappy tight and responsive and just sounds like music to your ears and the spl port is the total opposite and quite boomy but thats what we wanted anyway.
FYI a 2.5db gain is almost doubling the output. In most cases to get a 2.5 db gain you need to do both A. double your cone area and B. double your power.
I've accomplished the near impossible.
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mr1in6billion
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Re: I've accomplished the near impossible.
Almost doubling it? It's a ratio, so shouldn't it be more than doubling it?chew* wrote:FYI a 2.5db gain is almost doubling the output. In most cases to get a 2.5 db gain you need to do both A. double your cone area and B. double your power.
And this thread is worthless without pics.
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mr1in6billion
- Supporting Member
- Posts: 961
- Joined: August 28th, 2005, 9:06 pm
- Location: Fog City
