One more thing, the driver has more holes than are required to mount the driver which at first I just let be but after doing the stethoscope test (plastic tube low frequency sine wave to listen for leaks) I found they leaked badly. 5 Minute epoxy and no more issues with leaks anywhere (PL works). Didn't really affect the SPL as far as I can tell but I didn't re-measure and the key improvement is you don't get that awful air rushing sound playing low frequency sine waves and it helps driver pressurization and control.
I've had no issues with EQing it to flat and getting that "punch" EDM sound, aka when they throw 90 Hz on top of the 45 to cover up distortion and make it seem louder >.< yes that's a face of shame on you producers. Anyways I should probably do a SPL test of the high end of the pipe but I'd have to disconnect my mains in order to just measure the woofer response, needless to say it sounds way too good for the price and I have 0 fault width the subs "bandwidth", especially after a couple bands of EQ to deal with the room issues and balance the high end.
Now I'm attached to this sub and don't want to sell it :/// For whatever reason (maybe placement) it sounds better sound quality wise than my horn. Very slight differences but it does seem clearer (hard to describe). Will get back when have made conclusion. It really impresses the crap out of me.
Saba,
I am glad that the sub is working out so well for you, and also that the subjective quality of it makes your ears happy!
I am sure that your friend (the guy that you built those subs for) will like them a lot if you can stand to hand them over to him ! hehe
Good tip on filling those extra mounting holes, and also a good tip on how to find those leaks! very cool ..
I get that pesky dip in response around 80 or 90hz here at my place as well when i have tried to measure indoors ... I have also witnessed the same thing when trying to take measurements inside of other houses with different sized rooms (even odd shaped rooms) but the common factor was the 8 foot ceilings , which i am pretty sure is the cause ..... The dip will be most prominent at around center height between floor and ceiling and can get less pronounced when you move the measurement mic closer to the ceiling or floor but then you can end up with other crazy interactions from every other boundary or large object in the room, so i have pretty much given up on trying to get any decent measurements of bass indoors, unless the measurements are taken extremely close to the box which seems to negate the influence of the room .....
The room's 43hz resonant bump that you mentioned has the exact same contour on both the T60 and the ML-TP so yeah, thats a dead giveaway , definitely the room's effect ...
From the graph I can see that your room looks like it might have a resonant peak around 60hz , then there is your dreaded dip at 90 , then you may have another peak around 120hz .... Sound about right?
I am looking forward to any unfiltered outdoors measurements that you make , or even a lower power unfiltered measurement taken very near the mouth indoors...
I am glad that the sub is working out so well for you, and also that the subjective quality of it makes your ears happy!
I am sure that your friend (the guy that you built those subs for) will like them a lot if you can stand to hand them over to him !
heheGood tip on filling those extra mounting holes, and also a good tip on how to find those leaks! very cool ..
I get that pesky dip in response around 80 or 90hz here at my place as well when i have tried to measure indoors ... I have also witnessed the same thing when trying to take measurements inside of other houses with different sized rooms (even odd shaped rooms) but the common factor was the 8 foot ceilings , which i am pretty sure is the cause ..... The dip will be most prominent at around center height between floor and ceiling and can get less pronounced when you move the measurement mic closer to the ceiling or floor but then you can end up with other crazy interactions from every other boundary or large object in the room, so i have pretty much given up on trying to get any decent measurements of bass indoors, unless the measurements are taken extremely close to the box which seems to negate the influence of the room .....
The room's 43hz resonant bump that you mentioned has the exact same contour on both the T60 and the ML-TP so yeah, thats a dead giveaway , definitely the room's effect ...
From the graph I can see that your room looks like it might have a resonant peak around 60hz , then there is your dreaded dip at 90 , then you may have another peak around 120hz .... Sound about right?
I am looking forward to any unfiltered outdoors measurements that you make , or even a lower power unfiltered measurement taken very near the mouth indoors...
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Will need to do the THD measurements outside as 100 dB is all to easy corner loaded. Thing is the T60 measures ~3 percent distortion down at 25 Hz at 105 dB in room, so I'm sure it isn't the distortion that makes it sound less clear but rather a fequency or time domain response difference, still trying to figure out why i prefer the tapped pipe at the moment but experience tells me it most likely has the "better spot" in the room (they have different corners) but the T60 won't fit in the spot the pipe is in.
Saba,
I am glad that the sub is working out so well for you, and also that the subjective quality of it makes your ears happy!
I am sure that your friend (the guy that you built those subs for) will like them a lot if you can stand to hand them over to him !
Good tip on filling those extra mounting holes, and also a good tip on how to find those leaks! very cool ..
I get that pesky dip in response around 80 or 90hz here at my place as well when i have tried to measure indoors ... I have also witnessed the same thing when trying to take measurements inside of other houses with different sized rooms (even odd shaped rooms) but the common factor was the 8 foot ceilings , which i am pretty sure is the cause ..... The dip will be most prominent at around center height between floor and ceiling and can get less pronounced when you move the measurement mic closer to the ceiling or floor but then you can end up with other crazy interactions from every other boundary or large object in the room, so i have pretty much given up on trying to get any decent measurements of bass indoors, unless the measurements are taken extremely close to the box which seems to negate the influence of the room .....
The room's 43hz resonant bump that you mentioned has the exact same contour on both the T60 and the ML-TP so yeah, thats a dead giveaway , definitely the room's effect ...
From the graph I can see that your room looks like it might have a resonant peak around 60hz , then there is your dreaded dip at 90 , then you may have another peak around 120hz .... Sound about right?
I am looking forward to any unfiltered outdoors measurements that you make , or even a lower power unfiltered measurement taken very near the mouth indoors...
BFM made me paranoid about leaks, and rightfully so. People who are interested in horn designs stand a lot to learn from reading his plans. billfitzmaurice.com.
Resonant peak at 60 is most likely wall resonance ( I tend to get that)
However, the ceilling here is ~11 feet so it may be a different reason for the 90 Hz dip. However our ears are imperfect enough that I can't tell that I'm missing that spike at 90 Hz (nothing other than a sine wave test would pick up on it enough to worry about).
Ask and ye shall receive, here is a 3 inches from mouth away from the corner measurement done at a level where I had 0 worries about excursion, I took all filters EQ HP/LP etc off and here is the raw response in red with the HP LP no eq at all response in blue.
Yup that's looking nice.
Flat as a river stone to 117
Oh, the green line picture is just run up to 500 Hz for those who are interested.
Mind you guys that the simulation showed a 3 db dip from 55-100 Hz whereas the "measured value" is actually darn near flat, ofc it's not an ideal measurement (center of a room measured extreme nearfield) but it's the best I can do for now.
Yup that's looking nice.
Flat as a river stone to 117
Oh, the green line picture is just run up to 500 Hz for those who are interested.
Mind you guys that the simulation showed a 3 db dip from 55-100 Hz whereas the "measured value" is actually darn near flat, ofc it's not an ideal measurement (center of a room measured extreme nearfield) but it's the best I can do for now.
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I did a quick test at 40 Hz and it was 2.45 % total thd, didn't run for long at all because it was bloody loud and rattled the windows badly. The distortion of the fan in my room and rattling combined with slight coil whine/ humm ( gx 3 amplifier) are greater than any I can hear from the driver (can't run sine waves at full power I would destroy something). I'll get back to you if I get to do a distortion test outdoors where it won't shake so many things.
I actually changed it slightly from the "final CAD model" because I screwed up due to failure to label EVERYTHING. The only difference is the rear panel is shifted one wood thickness (3/4 inches) down. Other than that it's the following dimensions.
Here's my best effort at using solidworks to label all the pertinent details.
PS this is as close to "as built" as I can get the dimensions (added in the goof up).
Here's my best effort at using solidworks to label all the pertinent details.
PS this is as close to "as built" as I can get the dimensions (added in the goof up).
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Note my "actual brace" didn't have quite as many holes, I went to town when I was messing with solidworks. also, all my widths are only as accurate as the saw I was cutting on and I'm pretty sure the "5.25 inch" section could actually be 5.5 which shifts things over slightly, not too worried though as it shouldn't change much.
Saba ,
Thank you for getting those close measurements, its good to know that the saddle shaped response in the sim is really not an issue in reality. The same goes for the peak at the upper cutoff, its not nearly as bad as what we see in simulation
I typically care very little about saddles and peaks unless they are extreme because I expect to use EQ even if they do show up in the final measured result. I used 4 filters all with huge +- and widths to get the thing close to flat including room response, and that's starting with a relatively flat sub
. Efficiency and displacement limited power handling are what I look for (and why the sws looks appealing).
(-might add the port lengths to that drawing) - how is the constricted port shown in a hornresp model?
car speakers seem to offer a lot of value
1260W TQWT http://i.imgur.com/rdYbq3D.jpg
car speakers seem to offer a lot of value
1260W TQWT http://i.imgur.com/rdYbq3D.jpg
The driver I used is a car subwoofer, It's a few pages back but it's the alpine swe-10s4 and it has better performance per cubic foot that any 1260 design I've seen due to the cabinet size requirement discrepancy, even better however is the sws 10d4 and the lab 15 (special run) though.
Also, the port lengths are labeled. The width between those two panels is 6 inches, the distance between ports is also labeled, takes a little math but you can do it.
Also, the port lengths are labeled. The width between those two panels is 6 inches, the distance between ports is also labeled, takes a little math but you can do it.
oh yeah - and a good 35Hz is a lot of extension - should do theater and jazz organ well - plus this new design will fit a lot of trunks - I don't have a license currently due to long term balance issues - my only car with a trunk (tiny) may not run anymore plus was too loud for any normal stereo - hope its block didn't crack this last winter
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