Breaks in? I can't decide whether they broke down or broke up.The Paulinator said:
Anyway... mrfeedback you'll be glad to know that today I finally scraped together 2x AUD$30 for those WES drivers you wax poetic about for the subs . It's a pity though that they have foam surrounds. Never mind. I'll try and remember to order them tonight. Gotta get the sub amp going again too. 
Might just take the GainClone approach this time. Have to drop the rails a little bit though. I'll be sure to report the results.
skinny boy..
isobariks have a dip at midbass freqs i heard.
model it in winisdpro see how it is.i think it is worth it for cheap subs..i do want to make one sometime tho lol
but.because the box is half the size,the ports wil go much longer for same tuning wont they so not always useful.
my jbl 2226h box is being cut by a professional joiner, 175Litre, 50$ labour,50$ MDF = not so bad
mmmm low distortion!
isobariks have a dip at midbass freqs i heard.
model it in winisdpro see how it is.i think it is worth it for cheap subs..i do want to make one sometime tho lol
but.because the box is half the size,the ports wil go much longer for same tuning wont they
so not always useful.my jbl 2226h box is being cut by a professional joiner, 175Litre, 50$ labour,50$ MDF = not so bad
mmmm low distortion!
Pushing junk uphill with a pointy stick
Well now, I've had these pair of boxes going for a year now and it seemed high time to break new ground. for quite a while I had been looking closely at this tragic excuse for a speaker that Jaycar sells for AUD$50 (you can get it wholesale for about $28) http://www1.jaycar.com.au/productVi...d2=&pageNumber=&priceMin=&priceMax=&SUBCATID=
and seeing it was awful on paper, I plugged the details into WinISD and it really WAS awful. Look at that horrid Qts! Anyway, I thought "what the heck, time to live dangerously". So I cut a pair of holes in my boxes and covered up the old ones and re-tuned the boxes to 25 Hz with a port 102mm diameter x 57mm deep.
Most of the rotten response of these speakers is because when the port+box begins to load the cone at low frequencies, the speaker just throws it's hands in the air and says "too hard!" That means of course that the lack of LF is because of low cone excursion, and THAT means a bit of equalisation will by no means over-Xmax it.
Sooo.... I put a -6dB per octave low pass filter with a corner frequency of 15Hz in line with the sub amp so as the frequency goes down the drive goes up proportionally at 6dB per octave. I'll post a picture soon, but here is a graph of the frequency response from my normal listening position.
As you can see, the 50-35Hz needs a bit of sussing out, but the bit from 35 down is really nice. About 2dB rise at 28Hz and then down to level again all the way too 21Hz. I'll have to maybe make up a parametric equaliser or similar to straighten out this thing.
I measured the frequency response by using a gliding tone from 50Hz down to 16Hz in a little over 30 minutes. Analysed using CoolEdit 96. The rapid drop above 50Hz is because there is no signal above there, just ambient noise. This was WAY more fun that using an expensive driver!!
Well now, I've had these pair of boxes going for a year now and it seemed high time to break new ground. for quite a while I had been looking closely at this tragic excuse for a speaker that Jaycar sells for AUD$50 (you can get it wholesale for about $28) http://www1.jaycar.com.au/productVi...d2=&pageNumber=&priceMin=&priceMax=&SUBCATID=
and seeing it was awful on paper, I plugged the details into WinISD and it really WAS awful. Look at that horrid Qts! Anyway, I thought "what the heck, time to live dangerously". So I cut a pair of holes in my boxes and covered up the old ones and re-tuned the boxes to 25 Hz with a port 102mm diameter x 57mm deep.
Most of the rotten response of these speakers is because when the port+box begins to load the cone at low frequencies, the speaker just throws it's hands in the air and says "too hard!" That means of course that the lack of LF is because of low cone excursion, and THAT means a bit of equalisation will by no means over-Xmax it.
Sooo.... I put a -6dB per octave low pass filter with a corner frequency of 15Hz in line with the sub amp so as the frequency goes down the drive goes up proportionally at 6dB per octave. I'll post a picture soon, but here is a graph of the frequency response from my normal listening position.
As you can see, the 50-35Hz needs a bit of sussing out, but the bit from 35 down is really nice. About 2dB rise at 28Hz and then down to level again all the way too 21Hz.
I'll have to maybe make up a parametric equaliser or similar to straighten out this thing.I measured the frequency response by using a gliding tone from 50Hz down to 16Hz in a little over 30 minutes. Analysed using CoolEdit 96. The rapid drop above 50Hz is because there is no signal above there, just ambient noise. This was WAY more fun that using an expensive driver!!
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The left one. Notice the port - I made it out of an old plastic cable drum. Just cut it to the right length and guillotined the cheeks to a rectangular shape. Cost = zero. Actually it had to cover up the old rectangular port so that is why they are so large. The old speaker holes are covered with the wood cut from the new holes. Really ugly...
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Circlotron said:
First, Cool, gutsy, project! And I appreciated seeing your quantitative approach laid out so clearly.
If the plates covering the old driver cutouts are not glued on and you'd like some suggestions on how to do it so there are not objectionable protrusions from the box so that it can be finished more properly* I can provide some.
*Of course you could decide, as did a good friend of mine, to take pride in EXTREME functionalism. (But from some of the photos I gather that at least one member of the family is going to object.)
Or you could go mod and paint the plug one color the cabinets another and do a circular grill for the woofer in another?
(Na--doesn't go with the bird and flowers.)Or you could paint it and drape thin cloth of the same color over it? In anycase, it pays to keep the "financial controller" happy.
One question though; you say: "a pity though that they have foam surrounds." From what I've read here recently foam is good. Why do you think not?
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