software

I know what electro is going to say

"damn...."

I didn't know it was a SPL sub only....sorry electro that we didn't catch this earlier....sell it

 

Look back at post 123, I think thats right. At 30Hz your graph is down -18 dB, in other words there is no sound that low. At 40 hz you are still down -9db and thats your peak and your port tuning. Thats the problem, you need to be at 0dB or slightly higher. At 50 Hz it begins to roll off again, down 12dB and it gets worse from there.

The only way to get above 0dB is to seriously increase the box size, but the box and speaker is still peaky. It peaks at port tuning, only competition woofers do that. We call them one note wonders.

Even in the graph that you have you can see that, the only note being produced is 40 hz, it down -9dB only because the box is too small

sorry

 

Your box design is actually a well thought out size with a reasonable port. Many woofers would work well in it.

The graphs below is what we need to see in a box and woofer. Notice that in both graphs the Amplitude Responce goes above 0. Many purists will tell you that it should stay on 0, they are weird and have no clue. Up to +6 is acceptable as long as the graph is smooth and gently rounded. Mountains are typically bad (red graph). But if your in the trunk of a car and need to get into the passenger comartment, then a little peaky is OK. But be careful here. The red graph is really boarder line.

These graphs are from my Mercury (orange) which has a Polk Audio EX12. The other is from my sons Cavalier (red) with 2 PowerBass 12-inch woofers. Both cars sound great.

Judging from the graph which car is louder? Which hits Lower?

 

Almost forgot, the Mercury has a port tuned at 40 Hz and the Cavalier is tuned closer to 42 Hz. Not big difference in tuning. Different boxes like different speakers or is it the other way around.

I would still build your box, and then find the best speaker for it. But thats me. The smart way would be to choose three or four different speakers and then play with the program. Besause you will be in the trunk of a car, lets get a little peaky. The peak will change with port tuning, how low it gets will change with size.

With this info, look at the graphs above, which box is bigger?

 

Most of the time the manufactures will tell you wether the t/s parameters are measure with the coils in series or parallel.

Not much changes though from either wiring I believe...I know that the motor force(Bl) doubles when in series compared to when in parallel because of double the magnetic flux...good ole physics from last quarter lol