Here is what i have been working on for the last 2 months. My brother helped me finish 2 right before the new year. i have been taking my time finishing the last 4. i have 2 more coats of duratex to put on and then load the drivers. they should be done this weekend so i can listen to them and take some measurements.
built with 1/2" 5x5 sheets of baltic birtch. each box take a little less than 1 sheet. 4 boxes for me and 2 for my brother. i can't wait to fire them up!
you can see more photos here:
Tapped Horn build
i have one extra gallon of duratex. brand new still sealed. $40 + shipping if anyone is interested.
Bob
built with 1/2" 5x5 sheets of baltic birtch. each box take a little less than 1 sheet. 4 boxes for me and 2 for my brother. i can't wait to fire them up!
An externally hosted image should be here but it was not working when we last tested it.
An externally hosted image should be here but it was not working when we last tested it.
An externally hosted image should be here but it was not working when we last tested it.
you can see more photos here:
Tapped Horn build
i have one extra gallon of duratex. brand new still sealed. $40 + shipping if anyone is interested.
Bob
i'm using the MCM 55-2421. oh, these are not my first. i built 2 test boxes out of MDF last november. i posted about them in this thread: http://www.diyaudio.com/forums/subwoofers/154705-how-much-better-can-i-make-th.html
bob
bob
Cancellation is a possibility, as are phasing problems in the impulse response due to the length of L12.
However, this one is interesting, in that the whole first section could be a throat chamber, or it could be L12 and part of L23. When I build my quad-driver TH (split throats, drivers side by side, detailed in the collaborative thread), I saw a few dips that may have been cancellation related, but the response was pretty close to the predicted result so I did not sweat it. That one sounds great.
However, this one is interesting, in that the whole first section could be a throat chamber, or it could be L12 and part of L23. When I build my quad-driver TH (split throats, drivers side by side, detailed in the collaborative thread), I saw a few dips that may have been cancellation related, but the response was pretty close to the predicted result so I did not sweat it. That one sounds great.
i cut all the panels using a clamp on straight edge and a circular saw. a few cuts were done with a table saw. i took my time to make sure all the cuts were done right. i think it paid off because they went together very easy.
i should mention that i used PL Premium and 18 gauge brads to put these together. the PL is messy so make sure you wear something that you dont care about ruining. i then used a straight edge router bit to clean up the edges, bondo in all the brad holes, and sanded like crazy. i put on 1 coat of black latex paint on the out side, two coats in the throat area and 3 coats of duratex on the outside.
yes i live the pdx metro area. i think i got the handle idea from other boxes i looked at. i really did not want to cut another hole that could possibly leak air and 12 handles at $8 each really adds to the cost. i made a template my router could follow to cut all the handles. i think they turned out nice.
the 3.5" and 4" might be swapped. i did not have the original drawings in front of me when i made the digital drawing.
bob
i should mention that i used PL Premium and 18 gauge brads to put these together. the PL is messy so make sure you wear something that you dont care about ruining. i then used a straight edge router bit to clean up the edges, bondo in all the brad holes, and sanded like crazy. i put on 1 coat of black latex paint on the out side, two coats in the throat area and 3 coats of duratex on the outside.
yes i live the pdx metro area. i think i got the handle idea from other boxes i looked at. i really did not want to cut another hole that could possibly leak air and 12 handles at $8 each really adds to the cost. i made a template my router could follow to cut all the handles. i think they turned out nice.
the 3.5" and 4" might be swapped. i did not have the original drawings in front of me when i made the digital drawing.
bob
in case anyone is interested here is how this box models. i finally figured out how to use hornresp thanks to littlemike's tutorial on the AVS forum.
bob
An externally hosted image should be here but it was not working when we last tested it.
An externally hosted image should be here but it was not working when we last tested it.
bob
Lookin' good bko. I recall you're near pdx metro area?
I just got the shipment notification on my mcm's. I'm targeting 30hz or lower for HT however. I think I'll steal your rather nice handle idea.
Be sure to use an appropriate high-pass to protect your drivers. I've got a pair of MCM 55-2421s in a 30-Hz tapped horn currently, they will bottom out with extreme LFE (Batman Begins) when turned up (~105 dB at the couch, so only ~50 watts into the pair).
My THs are finally done! They look good and they sound good to my ear, but i'm a little embarrassed to post the final measurements. I'm not sure what went wrong. My test box had better measurements. Must be the 45s i put in the corners for the handles.
the full photo set can be seen here: Tapped Horn build
30hz 30db
35hz 49db
40hz 64db
45hz 70db
50hz 73db
55hz 76db
60hz 78db
65hz 80db
70hz 81db
75hz 82db
80hz 83db
85hz 84db
90hz 84db
95hz 86db
100hz 87db
bob
An externally hosted image should be here but it was not working when we last tested it.
An externally hosted image should be here but it was not working when we last tested it.
the full photo set can be seen here: Tapped Horn build
30hz 30db
35hz 49db
40hz 64db
45hz 70db
50hz 73db
55hz 76db
60hz 78db
65hz 80db
70hz 81db
75hz 82db
80hz 83db
85hz 84db
90hz 84db
95hz 86db
100hz 87db
bob
Last edited:
http://www.diyaudio.com/forums/subw...ecific-tapped-horn-thread-54.html#post1829475
yep, each reflector can make a big difference.....
yep, each reflector can make a big difference.....
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