"Hmmm, cant seem to make it look any good at all now, been playing with sliders for hours..."
are you sure that you have entered the driver parameters correctly? changing bl will change qes, qtc, fs, vas, and rms. do you have the spec sheet with the t/s parameters on it? what driver is it that you are working with?
The drivers are acoustic elegance av10h-8 subs. The only specs available are for dual 4ohm versions in series, mine are single 8 ohm. I dont really understand how the parsmeters relate to eachother.
Link to specs.
but both should model exactly the same. the key is if using the dual 4 ohm, resistance will double, but bl only goes up by root 2 (1.414) and inductance should scale with resistance so 2x resistance = 2x inductance.
after a few minutes I gave up with the tapped horn too.
it works in a front loaded horn, but it is extremely sensitive to parameters. I wouldn't suggest it for a first horn attempt.
sometimes it helps to have a "starting point". you can use that one to increase length and so on, but again, it is REALLY sensitive to each adjustment and that makes it very difficult to say with certainty that it will translate once built.
The thing im still not sure of is the arrangement of the voice coils. These drivers are also duall voice coil and I don't know if the specs are with the coils in series or not. Is there any way to tell?
it will have no effect on the performance in the horn.
that is what i was trying to get at earlier. if you wire and measure the t/s for the coils in series, you get one set of numbers, measured in parallel, you get another set of numbers, but...both will perform identically in the horn, except for the change in sensitivity of course.
s2 is the area in front of the driver and divided into sd gives the "compression ratio" of the horn. at 500/425 your compression ratio is only 1.25. you could increase it by reducing s2 and that may help smooth things out a little. compression ratios of less than about 3 are pretty conservative.
Thanks LTD02. I have had to reduce the size of the box a little. Im planning on putting it inside an old timber dresser so I have fixed dimensions to work with.
Its around 38x118x180cm after the external skin is accounted for. Thats around 800 litres.
Just a couple quick comments... dealing with 10" drivers, in a pair, you need as much Xmech as you can possibly find to do anything in a tapped horn below 20Hz worth doing. Look for as strong a cone as possible, the smaller the Vas the better (to keep the box size down), the closer you can get to 0.3 Qes the better.
I wouldn't use the AE 10" based on those specs. If they measure better, great, but that's the key - you need confirmed, measured parameters to do a tapped horn well. Sometimes you can get by if the published specs are close to reality.
For 10s that should work well in a TH, I have a list of them in my signature build thread. You're better off with 12s though if you're intent on going below 20Hz.