stuffing rocks - hZ - Tweakers' Asylum

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stuffing rocks

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Posted by hZ on May 7, 1999 at 23:15:30

In Reply to: Re: thanks for the input posted by Clayton Oxendine on May 7, 1999 at 21:14:47:

LOT of box coloration, eh? Never mind. I DO like a totally quiet box; I want the music, pure and clean. I'll go with stuffing in all the chambers, if/when I do such a project. Why can't I win the lottery so I can sit in my garage all day building speakers?! Seems sooooo unfair. =)

Speaking of stuffing... I got bored last night and opened up my sub. I removed the 2nd order 140 Hz low pass (left over from when it was just a passive sub) and added an acoustic-foam "hammock" behind the driver (got creative), holding pillow stuffing in the top back corner (I was totally surprised to see that I'd left that back wall untreated... I'd glued egg carton foam to the top and adjacent sides). Well, since I did two things, I don't know which one is the primary contributer, but WHOA... the sub has REALLY tightened up and sounds cleaner. It used to have a bit of the boominess common with subs, but now it's just precise (tighter sounding than the 4" drivers in the mains), and seems to extend lower. Maybe it was removing the series 13 mH, maybe breaking up a nasty standing wave, or mabye a little of both. I'm just glad I did it.

I also was reminded (looking at the inards of the Parapix amp) that the speaker level high pass was nothing more than just a series electrolytic of about 160 uF (125Hz@8Ohms). Ewwwwwwww. I added another 50 with a 0.47 poly cap, bringing the crossover down to about 96 Hz, closer to the HCM2's f3 of 80. That also made a noticable difference. The main's bottom end is a little fuller/tighter, making for a smoother transition to the sub, and the treble seems just a wee bit more airy. It's just mickey-moused right now... I'm gonna have to calculate the correct amount for an 80 Hz x-over point and include at least 5 uF worth of poly in the mix. I can't understand why I didn't think of this before rather than just stew about having such a high fixed x-over point.

Sorry for babbling. I'm so happy with the results of such simple tweaking and wanted to let someone know. My roomate's not likely to consciously notice any difference... though he and his girlfriend had the stereo up a bit louder than usual and were happily singing along... hehe.

I'm most curious what this recent project of yours was and how it turned out, though I realize you said you're feeling a bit burnt out because of it.

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Follow Ups Full Thread

Topic - drivers in series - hz 19:41:36 05/04/99 (19)

Re: drivers in series - mikeo 11:57:18 05/06/99 (1)

Re: drivers in series - hZ 18:56:06 05/06/99 (0)

Wire two identical drivers in parallel - Richard Greene 08:30:58 05/05/99 (13)

ok, but... - hZ 01:16:10 05/06/99 (12)

Why to avoid drivers connected in series ... - Richard Greene 13:20:12 05/06/99 (3)

I almost got it... - hZ 19:50:40 05/06/99 (2)

Re: I almost got it... - Lukasz F 01:29:07 05/07/99 (1)

thanks .nt. - hZ 23:20:53 05/07/99 (0)

Re: ok, but... - Lukasz F. 10:49:34 05/06/99 (7)

Re: ok, but... - hZ 19:32:58 05/06/99 (6)

Re: ok, but... - Clayton Oxendine 10:33:51 05/07/99 (5)

thanks for the input - hZ 14:26:09 05/07/99 (4)

Re: thanks for the input - Clayton Oxendine 21:14:47 05/07/99 (3)

stuffing rocks - hZ 23:15:30 05/07/99 (2)

Re: stuffing rocks - lukasz f 10:49:12 05/09/99 (1)

Re: yup, I know - hZ 20:34:28 05/10/99 (0)

Re: drivers in series - Alan Ersen 23:29:32 05/04/99 (2)

sensitivity, efficiency... difference? (nt) - hZ 00:52:26 05/06/99 (1)

Re: sensitivity, efficiency... difference? (nt) - Alan Ersen 23:41:54 05/06/99 (0)

Follow Ups

stuffing rocks - hZ 23:15:30 05/07/99 (2)

Re: stuffing rocks - lukasz f 10:49:12 05/09/99 (1)

Re: yup, I know - hZ 20:34:28 05/10/99 (0)

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