They always do meander a little bit, some of these guys have a way with changing even the most convinced of minds
Thanks for the links Oliver, I took a quick look and that's pretty much what I imagined, I'll have to dig around a bit in that thread for my "I gotta try this at some point" scrapbook
Hmm, I haven't followed the forums much for awhile now, but thought your sub system had already been worked out in a long thread quite awhile back.
Regardless, the needs of the app dictate the driver's specs, alignment, so don't know if the LAB 12 is even the right driver for yours.
FWIW, it's just a 'bulletproofed' Avatar/Adire Audio Shiva designed principally for car audio apps in the late ‘90s, so has some history in various vented, sealed, PR and BP alignments.
Personally, I used a pair + their 15" PRs to create a mini-Contrabass for a friend since it was a bipolar alignment in approximately the same cab layout, net Vb [~8-10 ft^3, I forget now] as Tom Danley's Servo-Drive Contrabass servo sub.
Tuned to ~14 Hz with 300 W/driver, it shook my old floating floor, stick built house pretty good back when the movie U-571 was the low bass reference recording and gave a more 'solid' performance at THX/DD/DTS reference in a below grade poured concrete basement HT app.
In a ½ WL long, low tuned tapped pipe horn similar to the DSL DTS10 and limited to the same ~two octaves, it will theoretically match it performance except for peak power handling, but the trade-off is a ~854 L net Vb cab, so wouldn’t be my first choice unless the room is either at least medium size, but allows optimum positioning or quite large for multiples based on the trials n’ tribulations of the folks using the DTS10: Danley DTS-10 "Super Spud" DIY kit
Simple bi-fold ‘BIB’ concept corner pipe horns are probably a better choice overall in most apps that allow multiple large cabs; otherwise, PR vented cabs are going to be the best bang/buck in a relatively small cab AFAIK, especially if a > ~60-80 Hz XO point is desired.
GM
LOL, that's a heck of a bomb to drop, it looks like the response is nearly the same!
I've decided that I'm just going to build the "proper pair" with mdf again because it's cheap and I keep going through and trying different designs, so there's no telling how long I'll have them. They're about 80% completed right now, I just have to finish working on the S3-S4 angled pieces (that are giving me grief, my old saw just doesn't cut like it used to!).
Before I button it up this afternoon, I do have one remaining question. From the worksheet posted by bjorno, it appears that the S1-S2 stuffing should be fairly thick and S3 should be thinner. I'd like to make sure that I have the stuffing perfect before I PLP the side on, can anyone confirm the appropriate stuffing amount? I'm planning on using a roll of fiberglass insulation because I have it handy already.
Edit: oh, and lordy, placement options abound, with the usable frequency response up to nearly 130 cycles, I'm wondering if these should become my new stands for mains. Might be a tradeoff, not using corner placements, but it seems like integration would be much better.
I sense lots of measurements and fiddling this weekend.
Before I button it up this afternoon, I do have one remaining question. From the worksheet posted by bjorno, it appears that the S1-S2 stuffing should be fairly thick and S3 should be thinner. I'd like to make sure that I have the stuffing perfect before I PLP the side on, can anyone confirm the appropriate stuffing amount? I'm planning on using a roll of fiberglass insulation because I have it handy already.
Edit: oh, and lordy, placement options abound, with the usable frequency response up to nearly 130 cycles, I'm wondering if these should become my new stands for mains. Might be a tradeoff, not using corner placements, but it seems like integration would be much better.
I sense lots of measurements and fiddling this weekend.
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The OD-ML-TL, my usage of proper pair was a contrast to the hastily assembled test version I did with a single driver just to see what the performance would be like.
That TQWT Oliver posted, which I believe to be along the lines of what you were talking about, is probably next on my project list, but I'll fire up a build thread if I do a couple of those.
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NWCgrad's OD_MLTL? Your link justs goes to the top of the page............ http://www.diyaudio.com/forums/atta...gn-bj-b-t-n-lab-12-od-ml-tl-final_f3-21hz.jpg
GM
GM
Sorry, it was meant to go to the post where I uploaded a picture of the one I built, it was a quick-ish assembly with extra glue and uglyness that I really did just to see how the OD-ML-TL would sound.
I've spent the last couple of days off and on putting together a pair of them with a lot more care. I have one finished and the second one just needs to have the driver opening routed and the last side glued on.
Here's the one that's done. (No finish work yet.) The other one is coming later today!
Attachments
I have a TTQWT design from bjorno and tb46 for my 18" maelstrom x driver. It is tuned down to 13 Hz before the freq resp plummets and cone excursion goes crazy (10 Hz HPF required).
However, the enclosure is rather large. I am beginning to think 4 sealed subs (~5 cu ft each) would provide a smoother in room response and with a little EQ could get decent output to single digits. There are some blu ray's with significant impact below 10 Hz, but I'm not sure its worth the pursuit.
I'm torn, as I have never had a bass system that could go lower than 25 Hz with any authority. Perhaps I should find another 18" driver that models well in the bjorno/tb46 TTQWT design and couple the pair with the LAB 12's. The TTWQT design's projected response gets wonky above 60 Hz. I could use the TTQWT for the ULF and the LAB's for 30 to 120 Hz (120.Hz is the upper limit for the .1 channel).
Advise always sought and carefully considered. I am closely watching DrDyna's experience with this build. I assume they would play nice with the TQWT's. I have both a Behringer and MiniDSP for knocking down the peaks, hopefully the mutli subs will minimize the nulls (should let the literature). I am learning a lot in this thread, I hope it keeps going.
However, the enclosure is rather large. I am beginning to think 4 sealed subs (~5 cu ft each) would provide a smoother in room response and with a little EQ could get decent output to single digits. There are some blu ray's with significant impact below 10 Hz, but I'm not sure its worth the pursuit.
I'm torn, as I have never had a bass system that could go lower than 25 Hz with any authority. Perhaps I should find another 18" driver that models well in the bjorno/tb46 TTQWT design and couple the pair with the LAB 12's. The TTWQT design's projected response gets wonky above 60 Hz. I could use the TTQWT for the ULF and the LAB's for 30 to 120 Hz (120.Hz is the upper limit for the .1 channel).
Advise always sought and carefully considered.
I am closely watching DrDyna's experience with this build. I assume they would play nice with the TQWT's. I have both a Behringer and MiniDSP for knocking down the peaks, hopefully the mutli subs will minimize the nulls (should let the literature). I am learning a lot in this thread, I hope it keeps going.
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I played with tb46's model on hornresp and it looked pretty good to my untrained eye. Everytime I learn something in hornresrep I forget it next time I use the program. It isn't vet intuitive to me.
Would be cool to "see" what his TTWQT looks like, I think it would be a great match to the Mal-X design he visualized for me. With bjorno and tb46 this adventure would have been stillborn.
I finished the second one yesterday and spent a little time listening to the pair of them. I'm going to have to have the placement dance, I think I'm going to end up with a lower LPF and subs toward the back of the room again, they sound a little anemic when they're up front like that. Plenty of wall-breathing down really low, but hardly any visceral "kick".
My girlfriend actually commented that she was "spoiled" on the tapped horns and wasn't very impressed..I'm going to blame 75% of it on placement.
Once I find a spot where I can get a little hair-raising out of em, I'll try some real full-power testing. To me, they have a lot of potential to be very musical and "vanishing act" type subs, but I might have to augment them with another giant tapped horn just to have something that'll suck the breath out of you for HT and for when the girl feels like dancing
My girlfriend actually commented that she was "spoiled" on the tapped horns and wasn't very impressed..I'm going to blame 75% of it on placement.
Once I find a spot where I can get a little hair-raising out of em, I'll try some real full-power testing. To me, they have a lot of potential to be very musical and "vanishing act" type subs, but I might have to augment them with another giant tapped horn just to have something that'll suck the breath out of you for HT and for when the girl feels like dancing
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