Help with WinISD, RE SE 12" box :(

chodecz · Post by **chodecz** » Wed Mar 22, 2006 5:35 am

Hi guys,
Im trying to design a box for a RE SE 12" sub (powered by JL 500/1). Im using both WinISD and http://www.bcae1.com to help me.

I checked RE website and they recommend for a SQL setup.. 1.8cuft ported with 32hz tuning. I input the data of the sub in WinISD and it came up with a 3.429cuft box. I then set the tuning to 32hz and found a better SPL gain overall. I think it will be much better for me to go with the 3.429cuft, I see a 2db gain in the 35hz region. Or if i tune the box to 35hz, the benefits are even better.

Would it be better to go with 1 or 2 round ports?? I was thinking of two 3" ports at about 6.70" length - the vent mach at this is 0.04. Is this good, or will there still be port noise of any kind? Also, what would be an optimal port to buy? I saw a Lightning Audio PNR AeroPort here.. http://www.crutchfield.com/S-ufh6m8qvvp ... &I=495PNR4
Would this provide benefits that it claims it does???

Please please, anyone give advice. Is there disadvantages as to making a box too big or tuning too high or low? (other than from what i can see in terms of Gain and SPL in WinISD)

Also, I noticed WinISD and http://www.bcae1.com produce different results for the ports!?! With two 3" ports, WinISD says vent length 8.44, and mach 0.04. http://www.bcae1.com says port length: 8.832", port area: 14.137"sq, port volume 0.072cuft. I also noticed WinISD doesnt calculate speaker displacement from box size volume??

Also, one last question... what would be the optimal setup out of these 2?
http://homepage.ntlworld.com/con2000/subssss.JPG

I know this may seem like a lot of questions, but I would greatly appreciate ANY advice. My system is relying on it

. :help:

Robert Wollenberg · Post by **Robert Wollenberg** » Wed Mar 22, 2006 5:48 am

Just my two cents worth, but you don't want to mix SQ and a "gain in the 35hz region." When you start getting gain in your enclosure, espeically a ported enclosure and even more so in a bandpass, with gain comes a lack of SQ. You end up with a hump in your frequency response that, like you said, gives you a gain at 35hz. Which means you don't have a flat response, which is what your after in the first place. A box is only going to be too big or too small based on the driver you're using. Some require bigger boxes to achieve a flat response. Some can do it in a small enclosure. Ports sorta work in the same way. Once you have your drive and you've build the box the correct size, the diameter, lengh and number of ports will change your tuned frequency and can totally mess up your enclosure if you don't calculate it all correctly. The sub is only one small piece of the equation. I'd rather have crappier subs in the right box than the best subs on the market in a totally f'ed up box.

Bwcad1 · Post by **Bwcad1** » Wed Mar 22, 2006 6:11 am

he is completely right! now for people like me who build one note wonders we want a huge peak that is very steep because we want a huge gain on 1-3 freqencys. for instance i just built a 6.6cf box for a single 18 tuned to 58hz and i had a 34db gain at 51hz. try and keep your ports on the same face as the sub you will see better results in overall preformance that way. tuning will come in as you decide if you want to go more tword the spl (dark side) or the sq side (good side) lol

32hz is the normal for a decent mix of both but imo its more sq 35hz isnt bad and will give you a small boost in spl... i use only precision sound products ports because they are incredibly well made and hold up very well have no noise IF INSTALLED CORRECTLY!!! i use these ports and they stand up to 150 decibles+ and do not create noise. although you cant hear anything else over 150 lol. im a big advocate of larger boxes in that you can always make them smaller. although almost 3.5 for a single 12 sounds a bit to big.

i would go with a box around 2.5cf tuned to 34hz. see what that gives you in ISD. as for ports 2 2 inch ports would be good and even 2 3 inch ports if you want to get a bit more spl.

smoker · Post by **smoker** » Wed Mar 22, 2006 6:17 am

i generally trot my ass up to home depot and get me some pvc pipe which i cut to length and bevel the inside edges to reduce turbulence.....but then again im a po boy

sinister audio · Post by **sinister audio** » Wed Mar 22, 2006 7:19 am

pvc works pretty decent and you can paint it so it looks better too. i usually use slot ports or pvc unless they want to pay extra for areo. and the reccomended RE box is a good box.

chodecz · Post by **chodecz** » Wed Mar 22, 2006 7:46 am

Thanks for the advice guys!

Ok. I put what Bwcad1 suggested compared to what RE recommend for SQL. What do you guys think?? Also, what is Ql ... 'Ql = 7.00'?????

Btw, I want a daily 'boom' setup.

Please any suggestions...

**EDIT** heres the link.. http://homepage.ntlworld.com/con2000/winisd.JPG

William from NOLA · Post by **William from NOLA** » Wed Mar 22, 2006 8:03 am

SQL is just SPL+SQ. A new word that doesn't mean what the letters stand for! lol

Bwcad1 · Post by **Bwcad1** » Wed Mar 22, 2006 8:18 am

the graph doesnt look to bad what kind of ports did you do on it?

chodecz · Post by **chodecz** » Wed Mar 22, 2006 8:22 am

both boxes have two 3" ports, vent lengths 16.18" and 18.07".

Bwcad1 · Post by **Bwcad1** » Wed Mar 22, 2006 8:24 am

what do you want more of spl or sq? i know you want to run this daily but hell i ran my 45hz box daily made everything hurt and made me want to puke sometimes because it was so loud if i tried to listen to it at full volume for more than a few mins. bye the way that box was doin mid to high 140s on music. im going on my lunch break ill get back to you after.