The "Pimpala" v2 6th order, Team Fi, DC 10k, Juicebox Lithium. 10k Is In!!!!

[bcpballer64]

154.9 @ 31? Holy fuck balls batman

[DTS909]

Those woofers movin more than ron jeremy in his prime.

[tboorn]

lol thanks guys its definitely getting down now, more vids to come for sure

[Triticum Agricolam]

Looks awesome!

Have you measured to verify where your chamber tunings are at? Just curious.

[diegoclass2010]

Holly crap! Its getting down and loves the lows! X2 on what Triticum Agricolam said I'm also interested

[tboorn]

i havent been able to do any testing yet, its my friends car so this weekend ill bust out my AMM-1 and pull some power factor/rise/dyno power numbers and throw together a little graph if i can. I love seeing that stuff as it is. but it seems to be playing around where my math said the tuning should be. it seems to be peaking around 29-31 and i tuned the inner chamber to 30hz IIRC so we shall see. ill see if i can find or write up the math i used to calculate tuning

[Triticum Agricolam]

Sounds good man. I'd love to hear back what you find. Series tuned boxes can be tricky since the chamber tunings interact with each other.

Another way to find the tuning (besides using an AMM-1) is to just watch the cones while playing sine wave tones. The frequencies where the cone moves the least are your tunings.

[tboorn]

yeah they are super tricky to try and figure out but i have a deep love of math and all things about it so i took a lot of time trying to plan it out perfectly. it was especially difficult since when tuning a series, like you said, both ports interact with each other. and the only formula ive been able to find in order to calculate them uses the same size port openings for both chambers, then changing the inner port to fit your needs. the problem i had was my outer port was already built, and trying to tune the inner section with the port that is for a box twice its size becomes a hassle, but i got it figured out and math usually doesnt lie, so it seems to be working like i wanted.

i used this formula

http://www.diysubwoofers.org/bnd/6thord4.htm

its the only one ive seen that really shows a relation towards the two chambers that seems to make the most sense.

[Triticum Agricolam]

Yeah, there just isn't much info out there on series tuned boxes. I'm familiar with the diysubwoofers.org article you linked, unfortunately my own experience has been that that way of calculating tunings is incorrect. It doesn't account for the fact that when you add the rear chamber, it raises the tuning of the front chamber significantly. Also, when you changed the tuning of the rear chamber, the front chamber tuning changes along with it. Its doesn't make any sense to me that that would happen, but it seems to be the case. I did an experiment with series tuned bandpass boxes a little while ago, I posted about it here: http://www.stevemeadedesigns.com/board/topic/199877-series-tuned-6th-order-bandpass-experiment/

[tboorn]

i feel it somewhat takes that into account when you calculate what the tuning would be with the rear because it has you subtract the length of the front port from the rear port in order to get the correct rear port length. actually as im typing this i understand what your saying about the front port never having to be accommodated for the rear port. hmm interesting. ill have to see when i get to do some testing