Ok, if the t/s are close to original you shouldn't have any problems.
You don't need to spend money on a woofer tester. You can use free software - LIMP (ARTA) or Room Eq Wizard and a homemade jig consisting of a couple 3.5mm cable ends and a single resistor (less than $2 worth of parts) and measure t/s that way.
Huh, what?
I have REW. And some spare 3.5mm ends.
Must google this. But, I'm in the middle of 1.5 weeks of hard-core training at work that started today. I doubt I'll be getting serious about anything other than work for a couple weeks or more. Thanks for the heads up though!
Xen 5.5 this week an LPI 101 starting next week. I'm sure at least one of you will know what that's all about.
DIY woofer tester. Can't believe I never thought to google that up before!
Btw, I hate google now. Yahoo Advance Search is better, IMO. At least if you know exactly what you're looking for. Google just tosses in anything it can think of that might be "similar" and doesn't trust me to know what words to use in my searches anymore. Booo, Google. You've really gone downhill lately!!!
You need the newest version of REW, the original version didn't have t/s measuring. If you look in the instructions they probably tell you all you need to know about the jig you need to make - but I'm not sure, I haven't checked.
I still use LIMP (ARTA) mostly because sometimes REW refuses to do the sweep for me and LIMP never fails. But the LIMP jig seems to work fine with REW so that's a bonus.
I still use LIMP (ARTA) mostly because sometimes REW refuses to do the sweep for me and LIMP never fails. But the LIMP jig seems to work fine with REW so that's a bonus.
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Hi,
The OD-TL in my simulation have in room a bandwidth of not less than 30 Hz to ~150Hz when placed near a wall but if near a corner down to ~21 Hz.
An OD-TL = Offset Driver Transmission-line ~= TQWT = Tapered-Quarter-Wave-Tube
T-TQWT = Tapped-Tapered-Quarter-Wave-Tube.
Submitting simulation of a T-TQWT that probably can be XO:ed at 150 Hz too(depending on how much stuffing is used and if accepting a small FR ripple)) but would have a wider BW Band-width than the OD-TL: minimum15 Hz or much lower if the terminus(opening) is placed as close as possible to a corner junction.
The purpose for simulating the T-TQWT as an OD-TL is to show the impact of placing damping material at frequencies above ~80 Hz where the T-TQWT when stuffed will inherit a very similar FR like the OD-TL indicates.
b
PS: No EQ is needed but a HPF should be chosen to define a suitable lower
cut-off frequency.
Attachments
Thank you for posting that, bjorno. It looks very interesting.
I have decided to stay with a horn type subwoofer though.
And unless I can figure out how to clone the DTS-20 design, I think I may build the THT-LP which I remembered is 18" wide. I already have the plans for it in fact.
Btw, the DTS-20 is kind of fascinating. It's a horn subwoofer that uses large PVC piping to couple the driver to the horn. Or something like that.
I have decided to stay with a horn type subwoofer though.
And unless I can figure out how to clone the DTS-20 design, I think I may build the THT-LP which I remembered is 18" wide. I already have the plans for it in fact.
Btw, the DTS-20 is kind of fascinating. It's a horn subwoofer that uses large PVC piping to couple the driver to the horn. Or something like that.
This old project of mine using an Adire Shiva might interest you (T-TQWT). Can't quite hang with high efficiency mains (anything over 95 db/w/m) but works great and more than a match for normal speakers.
http://www.diyaudio.com/forums/subwoofers/171322-tapped-tqwt-stuffing-stuff-line.html
http://www.diyaudio.com/forums/subwoofers/170277-opinions-needed-tapped-horn-drivers.html
http://www.diyaudio.com/forums/subwoofers/171322-tapped-tqwt-stuffing-stuff-line.html
http://www.diyaudio.com/forums/subwoofers/170277-opinions-needed-tapped-horn-drivers.html
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