Yeah, I know what you mean. It for sure jolted me out of my high SPL infrasonic invoked reverie. I tweaked my back so bad launching myself out of a beanbag 'chair' that I still have a hard time getting down on the floor and an even harder time getting up without help.
Even now, every time I audition a fairly serious HT, I mentally cringe during any really low LFE , keeping one eye cocked to the heavens, so to speak.
GM
Even now, every time I audition a fairly serious HT, I mentally cringe during any really low LFE , keeping one eye cocked to the heavens, so to speak.
GM
Ok, no underlayment. No cement board. Very well, I will have to go "conventional" and at least MDF, maybe even Baltic Birch (not that I see they sell it at the big box home improvement stores...). I still hold a candle for unconventional materials; I am hoping to find perhaps a monument maker (headstones) that can get "seconds." Kidding! But I wager that you could make a damned-near [cabinet] resonance free huge sub out of marble slabs, and upon your death it could serve as the family mausoleum 
I still was glancing at the foamboard insulation, but it's not that cheap and might not do good duty as a sub cabinet. Ah yes the problem of mounting a 50- or 100-LB driver to it...
My silliness aside, I am slithering towards some DIY build. I am settling on likely drivers. The Alpine R-series sound good and have been prostituted by a noted poster here 🙂 as well as on other forums. Or one of the Dayton 18" ones maybe...
I still was glancing at the foamboard insulation, but it's not that cheap and might not do good duty as a sub cabinet. Ah yes the problem of mounting a 50- or 100-LB driver to it...
My silliness aside, I am slithering towards some DIY build. I am settling on likely drivers. The Alpine R-series sound good and have been prostituted by a noted poster here 🙂 as well as on other forums. Or one of the Dayton 18" ones maybe...
Or "s" type, whatever...
I see that Alpine SWS15D4 (-D2) can be had for less than 1/2 of the MSRP -- that would be a pair for $230. Even if this is a previous years' model -- should I jump on this? Appears one or two would make a passable subwoofer, mayhap at Tapped Horn?
Must .... purchase electronic crap
.......must............ 
I see that Alpine SWS15D4 (-D2) can be had for less than 1/2 of the MSRP -- that would be a pair for $230. Even if this is a previous years' model -- should I jump on this? Appears one or two would make a passable subwoofer, mayhap at Tapped Horn?
Must .... purchase electronic crap
.......must............
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Based on just one positive response but egged on by all the good press they received in the recent past, I've committed myself* to a pair of the SWS-15D4. The price is right, curiously they sim very much like the pricier "R series" (of course, my Hornresp skills are about seven days old )... Also, there is a guy here considering the same drivers for a build:
http://www.diyaudio.com/forums/subwoofers/250573-alpine-sws-15d2-tapped-horn.html
So I will watch with interest. I am going to devote a token amount of time to studies, midterm exams, papers and all that, but i will be hatching plans to build a (perhaps!) working tapped horn, using conventional materials and methods even!
*I'm sure a lot of you wish I would commit myself. But here in FL they only keep you for up to 72 hours, and then they send you an insurance bill for a few thousand bucks. Seen it happen to a friend. Not pretty. As for me, they just haven't caught up with me yet, and I'm enjoying my remaining liberty while I can. :*)
http://www.diyaudio.com/forums/subwoofers/250573-alpine-sws-15d2-tapped-horn.html
So I will watch with interest. I am going to devote a token amount of time to studies, midterm exams, papers and all that, but i will be hatching plans to build a (perhaps!) working tapped horn, using conventional materials and methods even!
*I'm sure a lot of you wish I would commit myself. But here in FL they only keep you for up to 72 hours, and then they send you an insurance bill for a few thousand bucks. Seen it happen to a friend. Not pretty. As for me, they just haven't caught up with me yet, and I'm enjoying my remaining liberty while I can. :*)
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Ok, no underlayment. No cement board. Very well, I will have to go "conventional" and at least MDF, maybe even Baltic Birch (not that I see they sell it at the big box home improvement stores...). I still hold a candle for unconventional materials; I am hoping to find perhaps a monument maker (headstones) that can get "seconds." Kidding! But I wager that you could make a damned-near [cabinet] resonance free huge sub out of marble slabs, and upon your death it could serve as the family mausoleum
I still was glancing at the foamboard insulation, but it's not that cheap and might not do good duty as a sub cabinet. Ah yes the problem of mounting a 50- or 100-LB driver to it...
My silliness aside, I am slithering towards some DIY build. I am settling on likely drivers. The Alpine R-series sound good and have been prostituted by a noted poster here 🙂 as well as on other forums. Or one of the Dayton 18" ones maybe...
You might be able to find arauco (pine) plywood at home depot. It's cheaper than baltic birch for experimenting with
Arauco was good stuff, but have not seen any at Home Depot since stock was used up after the factory burned down some time ago.
You gotta know when [how] to fold 'em...
Based on conflicting wisdom, I may just go with the horrible $8/sheet OSD sheathing and just call it a prototype 🙂
In the planning stages...I came up with a single fold very simple layout (sorry no diagram--I'm working with graph paper.) Looks like with a single fold (just one panel inside?) I could reasonably get about 24-100 Hz +/- 5 db.
A general question: the sims show I could get stupid low if I wanted (e.g. mid teens) but would need like a 30 ft path. Rather than construct a maze for my first sub, should I try simpler (above)?
Also I have modelled a slightly lower corner (18 Hz) and reasonably flat with some peaks but no dips up to about 100 Hz; would that one be better?
Since I am still in the design phase, it comes down to how lazy do I want to be? Is 24 Hz and a ragged response worth it, or should I plot a betterer path for that elusive infrasonic response.
Based on conflicting wisdom, I may just go with the horrible $8/sheet OSD sheathing and just call it a prototype 🙂
In the planning stages...I came up with a single fold very simple layout (sorry no diagram--I'm working with graph paper.) Looks like with a single fold (just one panel inside?) I could reasonably get about 24-100 Hz +/- 5 db.
A general question: the sims show I could get stupid low if I wanted (e.g. mid teens) but would need like a 30 ft path. Rather than construct a maze for my first sub, should I try simpler (above)?
Also I have modelled a slightly lower corner (18 Hz) and reasonably flat with some peaks but no dips up to about 100 Hz; would that one be better?
Since I am still in the design phase, it comes down to how lazy do I want to be? Is 24 Hz and a ragged response worth it, or should I plot a betterer path for that elusive infrasonic response.
Attachments
What's your driver, again ?. Sorry I haven't pored through the whole thread.
For what it's worth, I made a crude video a few months back describing how to ballpark design a T-TQWT (reverse taper tapped horn). Should be applicable for TH too. http://www.youtube.com/watch?v=fjU__o5wEj8 . If you're driver doesn't model well in a TH, try a T-TQWT . The inverse applies too.
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2x Alpine 15" SWS-15D4:
Alpine Electronics of America, Inc.
I can model a TQWT and see what differences I get. Thank you.
Alpine Electronics of America, Inc.
I can model a TQWT and see what differences I get. Thank you.
Here's what I came up with (please double check the TS parameters - especially Bl since the data sheet didn't list all of them, had to use hornresp to calculate the missing parameters).
This is for a single driver with voice coils in series (not sure if the supplied Le is for series or parallel connection). The enclosure size is 217 liters and should hit the low notes. and is single fold friendly 🙂 Perfect for a prototype. Assuming I got all teh driver parameters right, you should be able to tweak the length and cross sectional areas a bit to suit your size & response requirements
PS. Don't be alarmed by the droop towards the low end. Room gain should fill it in.
This is for a single driver with voice coils in series (not sure if the supplied Le is for series or parallel connection). The enclosure size is 217 liters and should hit the low notes. and is single fold friendly 🙂 Perfect for a prototype. Assuming I got all teh driver parameters right, you should be able to tweak the length and cross sectional areas a bit to suit your size & response requirements
PS. Don't be alarmed by the droop towards the low end. Room gain should fill it in.
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Possible error: I calculate a MMD of 267.69 (verified that). Your other parameters agree with mine. The graphi is not quite as pretty with the correct values 🙂
No prob, I will hire it out as a foghorn!
I am impressed by the detailed graphs. What is the app?
I am impressed by the detailed graphs. What is the app?
Hi Djim,
Good observation..
No, I forgot that, it seams to be ~+3 dB to much of input Power if to stay within Max Rec. Volume-Velocity ( ~10 m/s Rms or<15 m Peak) when a Filter and Stuffing is in use.
b🙂
I done some more diddling with a T-TQWT, this time starting with Eazy Horn's suggestion. I can do as well or better with a "reasonable" (maybe single fold) TH sim. My best performer can do (supposedly) 95 db or better 15-137 Hz (not flat, but peaky > 48 Hz. However, this is with a L23 = 698 cm, that would be some folding. I can't recall reading anyone claim a T-TQWT did better than a TH, in fact quite the opposite. My "testing" would seem to confirm that. Now, whether my TH will do any better than your basic sealed box, remains to be simulated 🙂
I have posted my current hornresp.dat here, if anyone would like to download it and see the latest sims. I guess the next build should have a name. I have been calling it the Ijit Mark II or just Ijit II, what do you think?
http://bmmoser.myweb.usf.edu/shared/TEMP/
I have posted my current hornresp.dat here, if anyone would like to download it and see the latest sims. I guess the next build should have a name. I have been calling it the Ijit Mark II or just Ijit II, what do you think?
http://bmmoser.myweb.usf.edu/shared/TEMP/
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Lead me not into temptation....oops, too late!
Oh boy! The drivers arrived tonight. At first I thought there was a mistake.
One of the boxes was mis-labeled. Upon closer inspection, TWO (of four -- outer, inner) are mislabeled. I did not order a 6 1/2" marine speaker 🙂 The other one said it was a D2, not a D4 as ordered. No matter, each driver claims to be a "SWS-15D4" which is what was ordered. Curious: both drivers (and packages) appear new (also as claimed); are these some kind of weird factory seconds? 😕
No matter -- onward to test them.
From reading here I guess the basic method is to have the bare driver connected in free space (well, on a tile floor counts?) and run some sine waves at it. This I can do.
This is a temptation I do NOT need right now! I have one or is it two papers due in barely a week, not even researched yet. Plus two books to read. Does anyone know of a website DIY-Spanish-Literature? 🙂
Giving me my drivers on Spring Break is like [as some long forgotten comedian said] taking a reformed drug addict to a Grateful Dead concert
If Satan wants to supply me with a fully equipped CNC wood shop and, oh yes, a set of plans for these drivers, I will succumb! I can withdraw from the courses and probably be money ahead in the deal. I'm not afraid of losing my soul. Too late Mr. Beelzebub. According to one of my bumper stickers, "I had my soul removed to make room for all this sarcasm."
Actually pertinent to my embryonic design, I am considering push-push for dual drivers. Read up on this and it sounds like a valid idea to avoid having the sub walk around the room.
Now, if only I had someone in my life to
me on the priority tasks...
Oh boy! The drivers arrived tonight. At first I thought there was a mistake.
One of the boxes was mis-labeled. Upon closer inspection, TWO (of four -- outer, inner) are mislabeled. I did not order a 6 1/2" marine speaker 🙂 The other one said it was a D2, not a D4 as ordered. No matter, each driver claims to be a "SWS-15D4" which is what was ordered. Curious: both drivers (and packages) appear new (also as claimed); are these some kind of weird factory seconds? 😕No matter -- onward to test them.
From reading here I guess the basic method is to have the bare driver connected in free space (well, on a tile floor counts?) and run some sine waves at it. This I can do.
This is a temptation I do NOT need right now! I have one or is it two papers due in barely a week, not even researched yet. Plus two books to read. Does anyone know of a website DIY-Spanish-Literature? 🙂
Giving me my drivers on Spring Break is like [as some long forgotten comedian said] taking a reformed drug addict to a Grateful Dead concert
If Satan wants to supply me with a fully equipped CNC wood shop and, oh yes, a set of plans for these drivers, I will succumb! I can withdraw from the courses and probably be money ahead in the deal. I'm not afraid of losing my soul. Too late Mr. Beelzebub. According to one of my bumper stickers, "I had my soul removed to make room for all this sarcasm."
Actually pertinent to my embryonic design, I am considering push-push for dual drivers. Read up on this and it sounds like a valid idea to avoid having the sub walk around the room.Now, if only I had someone in my life to
me on the priority tasks...
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Hi Soldermizer,
Post #77: "...I am considering push-push for dual drivers."
Maybe a: PPSL T-TQWT or TH?
Any dual 15" horn (1/4 wave enclosure) will be large. By the way, for home use a T-TQWT may well be the better choice; it does not have the same delay as the TH, and it should simulate smaller than a TH.
Regards,
Post #77: "...I am considering push-push for dual drivers."
Maybe a: PPSL T-TQWT or TH?
Any dual 15" horn (1/4 wave enclosure) will be large. By the way, for home use a T-TQWT may well be the better choice; it does not have the same delay as the TH, and it should simulate smaller than a TH.
Regards,
Tell me more. What is PPSL? I know the others. Do you have a suggested sim for a TQWT? I tried a few and get less dB than doing a TH. I need to do more planning before being allowed near a lumber store 🙂
A famous wise-acre (actually I had a different word in mind but the auto-censor will not allow it, even though it is a perfectly allowable term for donkey, clown, as well as the part of your body you sit upon.) said something like: it would take a team of mathematicians laboring 100,000 years to produce the same error a single mathematician can produce in an hour with a computer. Change "team of mathematicians" to "team of speaker designers" and "single mathematician" to "Soldermizer" and you get the point...?
A famous wise-acre (actually I had a different word in mind but the auto-censor will not allow it, even though it is a perfectly allowable term for donkey, clown, as well as the part of your body you sit upon.) said something like: it would take a team of mathematicians laboring 100,000 years to produce the same error a single mathematician can produce in an hour with a computer. Change "team of mathematicians" to "team of speaker designers" and "single mathematician" to "Soldermizer" and you get the point...?
Hi Soldermizer,
Post #79: "Tell me more..."
I'm having some problems w/ the latest update of Hornresp right now, so I don't want to spend a lot of time w/ damping, and the Filter Wizard, but, for starters, here are two older examples of the enclosure forms in question:
Regards,
Post #79: "Tell me more..."
I'm having some problems w/ the latest update of Hornresp right now, so I don't want to spend a lot of time w/ damping, and the Filter Wizard, but, for starters, here are two older examples of the enclosure forms in question:
Regards,
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