JBell,
Yes please give us more info. I have 4 3015lf's ready for sub duty. I am trying to decide which to build, this mini or TDA's mini TH using a 15 rather then the 12. Not sure yet which will offer the most bang and also be the easier to move around.
I also have several MCM 10" drivers(no longer available) for tops. Would like to do something with those like what you are doing for tops. I have some Otop 12's. The cut outs for the handles are feedback magnets! Are you going to put the holes instead in the flairs?
Thanks Mike
Yes please give us more info. I have 4 3015lf's ready for sub duty. I am trying to decide which to build, this mini or TDA's mini TH using a 15 rather then the 12. Not sure yet which will offer the most bang and also be the easier to move around.
I also have several MCM 10" drivers(no longer available) for tops. Would like to do something with those like what you are doing for tops. I have some Otop 12's. The cut outs for the handles are feedback magnets! Are you going to put the holes instead in the flairs?
Thanks Mike
Mike:
I guess it all depends on what you want out of a sub on which design to use. If you want awesome 'kick' and 50hz on up is fine, oliver posted a great suggestion a few posts back. My cube is good to 40hz in pairs or more it looks like, so if really strong 40-70hz is your main goal, the cube looks good. I'll still say, screamers box is a great all around box -- you'd be hard pressed to beat it in the 'all around' category. As for anything else -- run hornresp first before building. The 3015lf really wants about 500sq.cm. at s2, anything less and you get a really bumpy ride pretty quick..
On the tops, yes ports in the flares. In the earlier pic I didn't have the ports cut in all of the cabinets yet. Yes, side ports are feedback magnets. Black paint kinda hides things, but I think you can see where I put the ports.
I'm not going to post anything on tops until tested. However I will say they were designed around standard 15x22 and 22x30 grills. The single driver cabinet perfectly cuts a pair of tops per sheet, and the dual driver cabinet has a little left over per sheet. Drivers are beta12a-2's. Since the demise of the 55-1740, I've been really scratching my head on what to do for tops. My hope is that this is the answer I've been looking for -- testing will tell for sure.
Best little box for the 55-1740 was my 12x12x24 box, 6" horn with a 'relaxed' melded array (35degree angle, not 45) with ports in the flares. Great sounding little box, loved it. Paired with dual 55-2421 FLH subs, a xti1000, and a mixer - it would put on a show on the cheap. I've also gone 'big' with the 55-1740... not sure it was totally worth it, small box was my favorite.
As soon as I get some time to do some testing, and some real world listening -- I'll update.
I guess it all depends on what you want out of a sub on which design to use. If you want awesome 'kick' and 50hz on up is fine, oliver posted a great suggestion a few posts back. My cube is good to 40hz in pairs or more it looks like, so if really strong 40-70hz is your main goal, the cube looks good. I'll still say, screamers box is a great all around box -- you'd be hard pressed to beat it in the 'all around' category. As for anything else -- run hornresp first before building. The 3015lf really wants about 500sq.cm. at s2, anything less and you get a really bumpy ride pretty quick..
On the tops, yes ports in the flares. In the earlier pic I didn't have the ports cut in all of the cabinets yet. Yes, side ports are feedback magnets. Black paint kinda hides things, but I think you can see where I put the ports.
I'm not going to post anything on tops until tested. However I will say they were designed around standard 15x22 and 22x30 grills. The single driver cabinet perfectly cuts a pair of tops per sheet, and the dual driver cabinet has a little left over per sheet. Drivers are beta12a-2's. Since the demise of the 55-1740, I've been really scratching my head on what to do for tops. My hope is that this is the answer I've been looking for -- testing will tell for sure.
Best little box for the 55-1740 was my 12x12x24 box, 6" horn with a 'relaxed' melded array (35degree angle, not 45) with ports in the flares. Great sounding little box, loved it. Paired with dual 55-2421 FLH subs, a xti1000, and a mixer - it would put on a show on the cheap. I've also gone 'big' with the 55-1740... not sure it was totally worth it, small box was my favorite.
As soon as I get some time to do some testing, and some real world listening -- I'll update.
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Thanks JBell for the info. Also wanted to point out on the bottom of page 36 Don Synder had some questions for you. I posted mine after his post, but it started a new page. Just want to make sure you see his post.
Here is Don's post.
Hi JBell,
How can we use the 2 ft cube? Will 4 units be enough? The dual 10" tops look interesting. Give me some more info, and I'll try to come up with
a plan. Are you going to use the 3k piezos for tweeters?
__________________
Don
Here is Don's post.
Hi JBell,
How can we use the 2 ft cube? Will 4 units be enough? The dual 10" tops look interesting. Give me some more info, and I'll try to come up with
a plan. Are you going to use the 3k piezos for tweeters?
__________________
Don
shawn.
Like the big box, the cube is a very simple design, and isn't exactly well tuned for upper bass. (140hz is tops for the cube in it's current state) This is the 'art' of designing a tapped horn -- to get 40hz, while also sounding good at 160hz. This is what tom does exceedingly well. Scott (screamers) about lost his mind working on his... because he ended up doing error by trial testing to finally get the upper bass 'tone' right.
I am certain that both designs can easily accomplish upper bass 160hz with a carefully designed reflector or small alteration to the horn path close to the throat (s2 area) In each TH I've built, I've found that is the area for trade offs. In the cube, with no reflectors, I got more 40hz than hornresp predicted, and a steeper drop at 160hz than predicted. There is your trade off. A couple shallow reflectors in the first couple bends will most likely alter that dramatically. (more 160, less 40)
For me personally, where I judge a subs performance by the 40hz yardstick... and I always cross at or under 100hz, the obvious trade off for me was to leave the extra 40hz in there. To answer don's question -- I believe that 2 or more cabinets is sufficient to get the 40-100hz bandwidth that I require.
On tops, I don't want to post design till I hear it. Selenium 220's with wave guides and piezo arrays will both be tried. According to hornresp, the tops hit hard at 100hz in 4pi space, so I think they'll be a good match for the cubes.
Like the big box, the cube is a very simple design, and isn't exactly well tuned for upper bass. (140hz is tops for the cube in it's current state) This is the 'art' of designing a tapped horn -- to get 40hz, while also sounding good at 160hz. This is what tom does exceedingly well. Scott (screamers) about lost his mind working on his... because he ended up doing error by trial testing to finally get the upper bass 'tone' right.
I am certain that both designs can easily accomplish upper bass 160hz with a carefully designed reflector or small alteration to the horn path close to the throat (s2 area) In each TH I've built, I've found that is the area for trade offs. In the cube, with no reflectors, I got more 40hz than hornresp predicted, and a steeper drop at 160hz than predicted. There is your trade off. A couple shallow reflectors in the first couple bends will most likely alter that dramatically. (more 160, less 40)
For me personally, where I judge a subs performance by the 40hz yardstick... and I always cross at or under 100hz, the obvious trade off for me was to leave the extra 40hz in there. To answer don's question -- I believe that 2 or more cabinets is sufficient to get the 40-100hz bandwidth that I require.
On tops, I don't want to post design till I hear it. Selenium 220's with wave guides and piezo arrays will both be tried. According to hornresp, the tops hit hard at 100hz in 4pi space, so I think they'll be a good match for the cubes.
Thanks Jim for all the info. I am happy with the performance of my OT 12's loaded with beta 12a-2's. For a cheap driver, it gives alot for the money.
I will be using the subs for DJ work. With crowds of less then 200. Mostly used for country, old rock, metal, pop, and a little hip hop. What do you think about 4 cubes handling sub duty for the small to med... bars, mostly under 100 people? Most rooms would be 24' x 40' or less in size.
Thanks Mike
I will be using the subs for DJ work. With crowds of less then 200. Mostly used for country, old rock, metal, pop, and a little hip hop. What do you think about 4 cubes handling sub duty for the small to med... bars, mostly under 100 people? Most rooms would be 24' x 40' or less in size.
Thanks Mike
4 would kill or overkill a 200 person bar, I think I would use a pair for that size room, but then I'm a little conservative compared to others on the volume knob. For dj work, you probably don't have the feedback issues on the OT12's -- sounds like you are good shape.
Don't face them into the corner like a FLH, they are directional. For 'corner loading' put them in the corner facing out to the diagonal corner. You can also just put them under your dj table facing the dance floor. You are -10db behind them, so you won't get killed with bass. (I know, this blows up all of the 'where do you put horn subs' rules you've been taught.)
Great thing is -- it's a single sheet of plywood per... so weight/size/cost are a definite bonus on the cube.
I can't state it loud enough for all reading these posts... YOU MUST HIGH PASS.... You don't, and you build this design -- you will have a scrap heap of a driver. If you don't have at least a 24db/oct high pass available, don't even try these designs. When they unload, they unload quick and the carnage is immediate and final. If you think the 30hz high pass on the back of your behringer or whatever amp is good enough -- it isn't.
40hz HP at 24db/oct. apologies for sounding cranky -- just don't want any blown up drivers on my account.
Hornresp says you are good to 63volts xmax wise from 40hz on up. Scott swears with his cabinet, he pushes past that up to about 700 watts (75v) all night long without anything getting hot. (about 13mm xmax at 60hz) That is beyond my comfort zone....
4 cabinets should get you 136db from 40hz-140hz +-1db at 63volts outdoors. If you push it like scott to 75v, you might just touch 140db, but I wouldn't bank on it.
Sounds like enough for a 200 person bar.
http://www.diyaudio.com/forums/subwoofers/127908-jbells-set-four-tapped-horns-34.html#post2229599
yes, this should work. I lay things out a little different on the laps than don did, but this works very well. The only part where what I built and don's plans don't match is were I didn't quite have the baffle 'long' enough. Aka, I brought i,c panels down past the end of the baffle board j, because it is easier to construct that way. My baffle was 15", so total length was 16". Don shows it 16.75 total length -- which is correct. What I built was about .75 short, meaning the back vertical horn path was slightly larger than it should have been. In this area of the horn, I don't think fractions of an inch matter. Close to the driver they matter ALOT.
If you have a table saw, the cube cuts out REAL quick, a 24" rip, and 23" rip length wise, then cross cut side,side,top,bottom from the 24", and all the rest of the parts from the 23" You should end up with about a 12x23 left over, that I used to make braces with. A note, I lost a db at 40hz by putting in the braces -- you may want to hole saw the braces some if you want that db back. btw -- scott found the same thing -- a solid brace reduces the amount of down low you get, he had to open up his brace on the vertical back horn path, to get some 40hz back.
In the end... nothing but dust left over.
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Braces are supposed to prevent panels from "panting" (moving) and robbing energy from the cabinet's output at the panel's resonant frequency.
Unfortunately, they also decrease volume in the cabinet, which reduces the cabinet's low frequency output slightly. The trick is to keep the panel's
resonant frequency out of the cabinet's bandpass.
In short ... there ain't no free lunch !!!
Unfortunately, they also decrease volume in the cabinet, which reduces the cabinet's low frequency output slightly. The trick is to keep the panel's
resonant frequency out of the cabinet's bandpass.
In short ... there ain't no free lunch !!!
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there he goes again
Jim,
So I'm doing an innocent search to find how much those DSL TH-118 sell for just for fun ($3,332), and find this bit of ego'tude from our old friend <sigh>
dj forums - The Worldwide DJ Community - View Single Post - My Danley TH-118 review
I'm convinced the directionality in a TH sub is the result of two sound sources: the front of the driver at the mouth and the rear of the driver delayed by the path length and with an inverted polarity. Which should be similar to a cardiod array but is probably only happening at the resonant frequency which is thankfully the lowest where it counts the most. Although time delay and polarity swapping are not the same, they effectively become the same at only one frequency.
Jim,
So I'm doing an innocent search to find how much those DSL TH-118 sell for just for fun ($3,332), and find this bit of ego'tude from our old friend <sigh>
dj forums - The Worldwide DJ Community - View Single Post - My Danley TH-118 review
I'm convinced the directionality in a TH sub is the result of two sound sources: the front of the driver at the mouth and the rear of the driver delayed by the path length and with an inverted polarity. Which should be similar to a cardiod array but is probably only happening at the resonant frequency which is thankfully the lowest where it counts the most. Although time delay and polarity swapping are not the same, they effectively become the same at only one frequency.
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