|
Audio Asylum Thread Printer Get a view of an entire thread on one page |
For Sale Ads |
209.226.237.77
In Reply to: Re: Using series capacitors to "boost" bass - here's one sim posted by freddyi on February 15, 2007 at 10:48:34:
Very good Freddyi, I am sure it will perform just like the curve says. You can tell by the impedance.I finally got your name right!
Follow Ups:
"freddi" was closer as my middle name starts with a "D" - ought to be "dummy" but parents weren't clarivoyant-- for fun, sure wish AJ did mutual load (can it be tricked?) - those things with driver in mooth need a method of accurate simlulation to lure diy-er's
over at Speakerplans, was contended that AJ & hornresp missed out on a large scoop
shunt with 400uF and 25mH inductor - L's dcr might matter - does this prediction look screwy to you?
That one looks a bit optimistic, but it does work. You can do the same thing with compression drivers, the right combination of components allows you to vary the Q of the filter for a steeper rolloff below f3 with higher sensitivity above. You can do the same with low pass filters too.
hi Bill - that's almost a dead short so take a real constant-voltage source to get gain up - then that amount looks kinda odd (?)
Ah, you noticed that. The way these things work is to reduce system impedance,up the current draw and literally suck more power out of the amp, but if you go overboard you'll reduce the impedance too much and end up with all sorts of problems. As always no such thing as a free lunch.
still seems screwy as had to up inductor's DCR quite a bit for acceptable resultssealed box ~3rd order case at top of thread with 500uF cap and no low Z dip looked a pretty good tradeoff
vented box - tuned too low
Upping the inductor DCR gets the impedance up but also reduces the effectiveness of the circuit. You have to diddle with both the cap and coil values to find the combination that gives the best compromise between response and impedance. The excursion price isn't a price per se, you'd get that if you used EQ to fatten the response too. On the other end of the spectrum you can use a 2nd order LP filter to flatten out the upper end of a horn, compensating where the LP function of the horn kills the highs. Same caution applies, you can overdo it and get too low a Z.
See below. Lots of good links in that thread, including documents, Spice, etc.
This post is made possible by the generous support of people like you and our sponsors: