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View Full Version : Bandpass question/discussion..



Savant
12-19-2002, 09:52 PM
Ok guys, here's the thingy..

First off, this plot is probably pointless since the woofer used isn't the one going in the box, I had to pick something that I thought 'might' be close (looking at TS-W1041DVC but there isn't on in WinISD and can't find the specs for those.. so.. guessing :p )

So.. now.. This is a 4th Order Bandpass.. has 4 ports (2.5" each, mach 0.01).. tuned to 115 Hz..

Here is the question.. would a 6th Order reduce the sag in the middle of the range? If so, how much? (guess).. How would I go about trying to figure out the front/rear chambers, ports, etc.. WinISD doesn't support 6th order..

I looked at maybe using straight ported but that's a bit off looking.. sealed might be the way to go on the 10"s too (the 12"s will be sealed I think.. maybe ported.. haven't tried plotting those yet)..

So.. 6th Order... ? Worth it for what I want? (that being the 10"s subs to run ~75Hz to ~175Hz)..


Here is the image (kinda *****.. sorry)

Thanks :)

Man.. that's bad.. K, front chamber 0.7 ft^3, rear chamber 0.405 ft^3.. frequency 115.. 4 2.5" ports 3.77" long.. If you need more info, let me know..

K.. the peaks are at +9dB, the valley at +5db.. 75 Hz (+6dB) is about the same as 175 Hz (+6.3dB)..

Savant
12-19-2002, 10:42 PM
Originally posted by Jmac
LOL, you're running 1800 watts man ! Sealed should be more than loud enough :)

Jmac-ster :)

Yeah.. but.. I was looking over some wireing diagrams today... a calculator.. there is NO way I can run all 1800 Watts.. that's like 260 Amp draw at clipping.. I bet my Alt is only 120amp (if I'm lucky).. So, I was looking at running the 12"s at about 200 Watt and the 10"s around 150.. (looking at wiring it that way too.. so if I run it up too high I'll blow fuses ;) )

Cause I'll be running so low (compared to what I could be) I'd rather maximize what I can.. bandpass is great for the range I want if 6th order flattens out that dip a bit (plenty of room in the back of my S-10 Blazer if it requires large boxes).. Just not sure how to go about checking it.. ya know?

Anyway.. I could probably get away with sealed on all 4 speakers.. but c'mon, what fun would that be??? :)

Savant
12-19-2002, 10:50 PM
A) I love a challenge.. if I mess it up and it sounds shi**y, I fall back to sealed/ported ;)

B) ported don't really increase SPL at the given tuned Hz, do they? I mean, a little, but not like bandpass (looking at around 9dB bandpass.. doubled 3 times in loudness, right? 3dB doubles perceived loudness?)..

C).. hmm.. *shrug* I get the idea you are trying to get me to do this the easy way :nono:


But, all in all.. you are probably right.. Ported and be done with it.. given the stock nature of the rest of the system, I'll still be drowned in Bass... *sigh*.. still, what's the point of trying to be an Audiophile if you don't get to make nifty stuff? :)

Savant
12-19-2002, 11:19 PM
*sigh*

I guess I have to agree.. unfortunately..

I'm looking at the ported, and it's a bi*** to get a smooth curve at around 115 Hz.. the sealed is pretty smooth, a bit of a hump at ~92 - ~100.. but only like 2 dB higher than the low points in what I'm shooting for..

Oh well.. Unless I get the T/S.. I guess I don't have much of a choice, huh?

I'll keep my fingers crossed for those specs when the speakers get here :) If I get them, you are gonna have to help me find a 6th order plotter ;)


If I'm gonna go sealed.. would it be better to go iso-baric? To do that, are they in phase or out (they push on each other, or help each other).. That has a much smoother curve, like .5 dB across the whole 100 Hz.. Though, I'm not entirely sure what is required to make a solid iso-baric setup..

Savant
12-19-2002, 11:25 PM
WinISD Beta 0.44... no idea.. got it from their site..

Does Pro do 6th order?