What the heck is a Tapped Horn???

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It's a bandpass horn where both sides of the driver diaphragm are used to contribute to the sound. How high or low they will go depends quite a bit on both the driver and the horn design. A good design can get you around 3 octaves - it's a little tricky to get them right.

My own tapped horn uses two Tang Band 8x12" woofers and has a bandwidth of 16-80Hz. Not perfect, but it was a first time effort. It will do above 80Hz, but not with the same sound quality you get in the passband. It's tolerable up to about 100Hz, but I don't usually let it play that high.
 
I'd like to know if you can mount two woofers in one enclosure and get some impulse compensation? Would this still be 6dB louder than one woofer and do I have to double the crosssections too?
Those rectangular Tangband woofers seem efficient to put in pairs into an enclosure.
 
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I haven't really tried too hard in modeling only one of the TB woofers, but I can say they like big boxes whether you use only one or two. I went with two because I thought if I didn't, people wouldn't think I was crazy enough ;)

I did get slightly better modeling results using two for the 16Hz corner I was after, but I'm not sure if that's just because I gave up on only using one due to SPL and Xmax limitations.

Mine ended up being 74x42x17" - it's absolutely huge. I did everything I could to get the size down, but those woofers weren't having any of it. Got a design on the drawing table that does the same job at higher SPL in about 60% of the space.

I'll leave the impulse compensation part to those a little further down the learning road than I am. I've only tried the tapped horn thing once so far ;)
 
I'd like to know if you can mount two woofers in one enclosure and get some impulse compensation? Would this still be 6dB louder than one woofer and do I have to double the crosssections too?
Those rectangular Tangband woofers seem efficient to put in pairs into an enclosure.
If I understand you, no. The impulse response is a function of the frequency response, of the whole system the tuned pipe included. In my mind the two woofers sum to be one synthetic woofer driving the pipe.

You could mount one woofer reversed to reduce some distortion products,frm memory the 2nd harmonic
 
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Chris661: interesting you mention this, since a sealed box causes 2HD by itself due to the compression of the air. There is an equation floating around which can give you an indication. I think the linkwitzlab thor subpages showed this. Whether or not it matters compared to the distortion of the subwoofer itself is another issue.
 

GM

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Joined 2003
I'd like to know if you can mount two woofers in one enclosure and get some impulse compensation? Would this still be 6dB louder than one woofer and do I have to double the crosssections too?
Those rectangular Tangband woofers seem efficient to put in pairs into an enclosure.

As already noted, in the horn's pass-band the drivers become a summed unit unless physically spread > ~1/3 WL apart.

Right, to get the extra 3 dB of acoustic gain you have to double the horn's net volume (Vb), i.e. double its cross sectional area (CSA).

GM
 
W8Q-1071F:

Thanks! I get 314+ L for a 12.96 Hz DTS concept, so you're right, not exactly petite, but not too bad though considering its theoretical ability to meet DD/DTS/THX reference down to 16 Hz in 1pi space on only 170 W.

GM
 

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post 10 pic.
The box looks too wide for the drivers.
Chop 3 to 4inches off the internal width and that will reduce the volume by about 20%.

It's as wide as it is because the compression ratio is 3.25:1 - I was worried about what I could get away with on those woofers. I probably didn't need to - they like it just fine.

Thanks! I get 314+ L for a 12.96 Hz DTS concept, so you're right, not exactly petite, but not too bad though considering its theoretical ability to meet DD/DTS/THX reference down to 16 Hz in 1pi space on only 170 W.

Yeah - they're quite good woofers for tapped horns. My double effort is 650L. The response isn't quite as smooth as it could be, but this was a first time effort and I wanted an easy fold so compromises were made.

It still sounds great though. SPL wise, I don't know what it'll really do in anything but eighth space because it's too big to move around much and I don't have the measurement gear. I will say I got mid 120's at one meter while it was doing reference at my listening position.

I haven't seen its upper limits yet. Most of the time I don't like my movies that loud... I'm just content to have some headroom I didn't with the old sub.
 

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