We did it! And it is awesome! We finished up on Monday night with the first one. Sealed, tested and delivered....
So how did it do? It was too late to do the testing outside, so I tested it in the media room downstairs. I have to keep my neighbors happy ya know...
I have attached a picture of the measurement of SPL and phase. I think we were pretty close to the design, but I would like to get everyone's opinion.
I have also attached a picture of the project about half way through. I don't have final pictures yet because I haven't done any final finishing yet. I wanted to get everyone's opinion on any tweaks that I should do before putting any finish on. Right now it is still pretty easy to get into from any side.
I ended up making the side pieces a little longer which gives it feet and brings the sub up from the ground along with giving us a place for the cable to come down through the front piece and floor and out the back. I found that the easiest way to put the thing together was to lay the glued boards down on to one of the sides, measure all of the pieces and where they belong, trace the boards (as you can see in the picture), and then put the other side below the previously traced side piece and do all of the pre drill work for the screws. In other words drill through both boards. What this allowed us to do was then know where to put the screws for both sides. We didn't want to miss any of the inside boards ya know....
You will also notice that I put a couple of extra braces on the sides of the driver. I figured that the sound risk was probably low, but that the the half inch of wood holding the driver might not hold up over the long term.
How does it sound? VERY NICE! There is a notch at around 30hz which seems to be related to the resonant frequency of the driver. You can also see where the phase kicks in. I think I might have too much stuffing in the back (tail) pipe which might be affecting the lower extension. I put a ton of stuffing in there. Also, keep in mind, that I am not using a high tech mic or any kind of a fancy sound card. And I know that the mic doesn't do well at all on the low end.
I am definitely going to finish the other one as well. But before I do, I would like to get feedback on any tweaks that I should try out or perform. If any. Or better yet if anyone wants to experiment with some new idea, let me know, and I am willing to try it out on the second one. I am currently driving the 4ohm load with an old Acurus amp, but have a few others laying around. I can test a 7.1 100W Pioneer to see if it holds up, I have a few different Adcom's, a Rotel and a few 100W tripath based boards if someone is interested in seeing an amp melt down and what that looks like.
I just love this thing. It has got to be the best sub I have ever built. And I have built a few in my day. And none of them have been as clean on the low end.
Thanks again everyone.
I look forward to everyone's comments.
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Hi uptime,
Looks like you got a winner. Wonder what that little response irregularity around 30Hz is from? Is it the mike? Could there be a leak at the driver mounting gasket that mainly shows up when you hit resonance? You might want to play a little with the stuffing, as suggested in the drawing in Post #180 ("I put a ton of stuffing in there." - That worries me a little
.) Also, don't forget about bjorno's series inductor suggestion from Post #172, something interesting to try.
The main difference to the drawing is, that the front/back/top/bottom boards in the drawing are not inserted between the sides, but are attached to the outside of the side boards. The idea was to make them more easily removable. With the removable boards inserted between the side you may want to add full-length corner cleats to mount removable boards, and use weatherstripping for a seal.
Regards,
Looks like you got a winner. Wonder what that little response irregularity around 30Hz is from? Is it the mike? Could there be a leak at the driver mounting gasket that mainly shows up when you hit resonance? You might want to play a little with the stuffing, as suggested in the drawing in Post #180 ("I put a ton of stuffing in there." - That worries me a little
.) Also, don't forget about bjorno's series inductor suggestion from Post #172, something interesting to try.The main difference to the drawing is, that the front/back/top/bottom boards in the drawing are not inserted between the sides, but are attached to the outside of the side boards. The idea was to make them more easily removable. With the removable boards inserted between the side you may want to add full-length corner cleats to mount removable boards, and use weatherstripping for a seal.
Regards,
Yeah, I think you may be right. I do think that there is a little resonance going on because at certain low frequencies and high volume, I can hear some leakage. Almost a flap or flutter. Which is of course why we didn't seal everything up and lock it down. All of the sides/front are holding together very nicely and no leaks. It has to be around the driver. Nobody around here listens to it at the volumes it takes to make it flutter, so it hasn't been a problem, but it is still something I am going to tackle when I have some time this week.
So, yes, you are right about the front and back. And I really debated that as well. I may still do it that way for the other one. Or maybe after I crack open this one. So the thinking went like this, right now I can take all of the sides off, but if I wanted to only take one piece off (the side) to get in and change something, it would be nice to have just one of the sides, not the front and back have to come off. But in this case (because of the driver), and in the long run, it would be nice to be able to take three off. And it holds together pretty well either way. So I think I will try the other one the way you have the drawing and let you know which way I like it better and let you know.
About the stuffing, I only had the lighter fill, so I had to put more of it in. I used my wife's tulle to hold it all in and stapled it down. It worked out real nice because the back layed out flat, including the top stuffing, I could staple everything down, and then fold/roll it all up and put the screws in. What this allows me to do now is undo the screws, take the side off, unfold it all and take some stuffing out without having to unstaple everything.
Anyway, it's all just thoughts. I am a pretty flexible guy and pragmatic. And I am willing to try anything at least a few times. If I had a way to cut groves, I would probably make the front and back slide in and then screw them down. Probably be a lot more stable.
Thanks again for hanging in there with me.
So, yes, you are right about the front and back. And I really debated that as well. I may still do it that way for the other one. Or maybe after I crack open this one. So the thinking went like this, right now I can take all of the sides off, but if I wanted to only take one piece off (the side) to get in and change something, it would be nice to have just one of the sides, not the front and back have to come off. But in this case (because of the driver), and in the long run, it would be nice to be able to take three off. And it holds together pretty well either way. So I think I will try the other one the way you have the drawing and let you know which way I like it better and let you know.
About the stuffing, I only had the lighter fill, so I had to put more of it in. I used my wife's tulle to hold it all in and stapled it down. It worked out real nice because the back layed out flat, including the top stuffing, I could staple everything down, and then fold/roll it all up and put the screws in. What this allows me to do now is undo the screws, take the side off, unfold it all and take some stuffing out without having to unstaple everything.
Anyway, it's all just thoughts. I am a pretty flexible guy and pragmatic. And I am willing to try anything at least a few times. If I had a way to cut groves, I would probably make the front and back slide in and then screw them down. Probably be a lot more stable.
Thanks again for hanging in there with me.
Hi uptime,
Just two more thoughts: tulle is usually very tightly woven, maybe a loose weave cheesecloth would be a better choice; and an occasional dowel (or piece of wood scrap) between the back (or front) board and nearest inside board can't hurt, even though these boards are pretty narrow to begin with.
Regards,
Just two more thoughts: tulle is usually very tightly woven, maybe a loose weave cheesecloth would be a better choice; and an occasional dowel (or piece of wood scrap) between the back (or front) board and nearest inside board can't hurt, even though these boards are pretty narrow to begin with.
Regards,
That tang band driver is not available anymore
Tang Band W8Q-1071F 8"x12" Subwoofer 264-838
is there a another driver they sell that could be a good substitute without changing the box size too much?
thanks
Tang Band W8Q-1071F 8"x12" Subwoofer 264-838
is there a another driver they sell that could be a good substitute without changing the box size too much?
thanks
Thanks OW for the link ...
also a question for you, TB46 and Bjorno ... I am in the process of building 2 X 15" ported subs in 13 cu ft enclosures as part of the riser in my theatre (room size is 14' X 23' - both rear firing - riser 5' from back wall) )
the question is do you forsee a problem with building one or 2 of these single or double subs to put at front of theatre? built into a stage
also a question for you, TB46 and Bjorno ... I am in the process of building 2 X 15" ported subs in 13 cu ft enclosures as part of the riser in my theatre (room size is 14' X 23' - both rear firing - riser 5' from back wall) )
the question is do you forsee a problem with building one or 2 of these single or double subs to put at front of theatre? built into a stage
Hi Scruffyht,
Basically, that should be OK. You might want to start a new thread, and provide some room sketches, etc. For starters: http://www.diyaudio.com/forums/subwoofers/134568-multiple-small-subs-geddes-approach.html - start with the link in Post #5; and, http://www.diyaudio.com/forums/subwoofers/160879-build-your-own-2x12-th.html - folded tapped horns (or bjorno's T-TQWTs) could make nice risers.
Regards,
Basically, that should be OK. You might want to start a new thread, and provide some room sketches, etc. For starters: http://www.diyaudio.com/forums/subwoofers/134568-multiple-small-subs-geddes-approach.html - start with the link in Post #5; and, http://www.diyaudio.com/forums/subwoofers/160879-build-your-own-2x12-th.html - folded tapped horns (or bjorno's T-TQWTs) could make nice risers.
Regards,
Just chiming in, the original dual driver sub seems to have really came to life the last week or to, so to speak. Apparently the drivers have broken in. I had to turn the gain on the amplifier back about 25 percent.
I am finishing my basement remodel and i want to build something rediculous for it...........need to find a suitable larger driver.
I am finishing my basement remodel and i want to build something rediculous for it...........need to find a suitable larger driver.
Heres something rediculous!
http://www.diyaudio.com/forums/subwoofers/210339-tapped-horn-th-121-build.html
http://www.diyaudio.com/forums/subwoofers/210339-tapped-horn-th-121-build.html
No EQ for me. I think TQWT (love the way these sound) with a few 12's or even a 15 would be great. My main caveot is that I have an APA150 from dayton audio for the project, so maximum output with minimum input voltage is what I will need once again. I have a feeling that I have not even come close to pushing the dual 8X12 speaker to its limits, which are substantial.
And two equals true love....
Once again, I just wanted to thank everyone for their help on this one. And the second one! We built the second box and this time using better stuffing and not as much. And they are both very nice! There is just something about having nice bass response in stereo. I personally just find that I really don't like bass coming from one side of the room no matter where you put it. And since I already have two 72 inch ribbons, these go very nicely right next door to them.
Since we built them, I have built two more traditional ported speakers using a Hivi m8n, a Tang Band W5-704D, and a Dayton Audio PT2C-8 Planar Tweeter. I hung them in my home office, and I must say that they make for a very nice combination in that room. If anyone is interested, I would be happy to start a new thread.
My next project is one in where I am going to attempt to make a bit smaller set of speakers, but I have really come to like the bass response from these larger drivers. I have tried a bunch of drivers, and I must say that I am still partial to ribbons for the mid to highs and the tang bands and hivi's for everything else. But I am willing to be convinced to try anything. As long as they are affordable.
On the next one (a three way), and because I am trying to make them smaller, I am thinking of either a sealed box for the sub or something like a horn. On these, I would still like to focus on the low end. I would also like everyone's opinion on it, but I will start a new thread.
Anyway, a big thanks goes out to bjorno, tb46, Permo and the rest of the gang for making all of this possible.
Once again, I just wanted to thank everyone for their help on this one. And the second one! We built the second box and this time using better stuffing and not as much. And they are both very nice! There is just something about having nice bass response in stereo. I personally just find that I really don't like bass coming from one side of the room no matter where you put it. And since I already have two 72 inch ribbons, these go very nicely right next door to them.
Since we built them, I have built two more traditional ported speakers using a Hivi m8n, a Tang Band W5-704D, and a Dayton Audio PT2C-8 Planar Tweeter. I hung them in my home office, and I must say that they make for a very nice combination in that room. If anyone is interested, I would be happy to start a new thread.
My next project is one in where I am going to attempt to make a bit smaller set of speakers, but I have really come to like the bass response from these larger drivers. I have tried a bunch of drivers, and I must say that I am still partial to ribbons for the mid to highs and the tang bands and hivi's for everything else. But I am willing to be convinced to try anything. As long as they are affordable.
On the next one (a three way), and because I am trying to make them smaller, I am thinking of either a sealed box for the sub or something like a horn. On these, I would still like to focus on the low end. I would also like everyone's opinion on it, but I will start a new thread.
Anyway, a big thanks goes out to bjorno, tb46, Permo and the rest of the gang for making all of this possible.
Once again, I just wanted to thank everyone for their help on this one. And the second one! We built the second box and this time using better stuffing and not as much. And they are both very nice! There is just something about having nice bass response in stereo. I personally just find that I really don't like bass coming from one side of the room no matter where you put it. And since I already have two 72 inch ribbons, these go very nicely right next door to them.
Since we built them, I have built two more traditional ported speakers using a Hivi m8n, a Tang Band W5-704D, and a Dayton Audio PT2C-8 Planar Tweeter. I hung them in my home office, and I must say that they make for a very nice combination in that room. If anyone is interested, I would be happy to start a new thread.
My next project is one in where I am going to attempt to make a bit smaller set of speakers, but I have really come to like the bass response from these larger drivers. I have tried a bunch of drivers, and I must say that I am still partial to ribbons for the mid to highs and the tang bands and hivi's for everything else. But I am willing to be convinced to try anything. As long as they are affordable.
On the next one (a three way), and because I am trying to make them smaller, I am thinking of either a sealed box for the sub or something like a horn. On these, I would still like to focus on the low end. I would also like everyone's opinion on it, but I will start a new thread.
Anyway, a big thanks goes out to bjorno, tb46, Permo and the rest of the gang for making all of this possible.
Hi,
Thank you for your feedback, always nice to read.
Sealed subs are always a good idea but I prefer a single T-TQWT as main sub
together with a couple of smaller ( 15-20 L) lateral placed closed box subs.
Submitting a picture of a smaller T-TQWT using a favorite driver, the Wavecor
-SW178WA01 that provides IMO,IME outstanding SQ (Music use).
b
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I haven't forgot about you guys, I will be starting another project soon and I can't wait to work with everybody on it again.
I think I am going to wait for the 8X12's to go on sale again and buy 4 of them......?
This sub has impressed everybody that has heard and seen it, its beautiful, sounds great and is quite a conversation piece.
I think I am going to wait for the 8X12's to go on sale again and buy 4 of them......?
This sub has impressed everybody that has heard and seen it, its beautiful, sounds great and is quite a conversation piece.
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