Tapped-Horns for "Gallery Style" bass

[Brian Steele]

Just curious if any of you have used or are interested in trying out tapped-horns for gallery style bass..

A tapped-horn is basically a horn that has the subwoofer driver mounted within the horn itself, usually close to the mouth. The advantages of this design are higher efficiency when compared to simple sealed or vented designs, greater bandwidth compared to typical high-efficiency bandpass designs and smaller box size and lower cutoff efficiency when compared to true horns. It's not something I'd use for SQ, or even for peak SPL competitions where one-note bass is actually a requirement, but it might work well if you want gallery-style bass on a budget and you've got the space to spare

[nervewrecker]

they use rear loaded horns:

http://forums.trinituner.com/forums/vie ... light=horn



http://www.mktrinievents.com/forum/phpB ... =23&t=1131

[Brian Steele]

they use rear loaded horns:

Were those properly-designed, or did the builders "try a ting"?

Rear-loaded horns require drivers with high Fs and low Qes and are not known for their low bass capabilities (there's a direct link between not only horn length, but mouth size and low frequency capability). A properly-designed tapped horn of the same volume will give better low bass at the expense of output around 100 Hz or so, primarily because the mouth size can be a lot smaller.

[jeff]

slacker jack actually tapped horns are totally different topic

they looks like this


i heard one already but i find the size of the enclosure sometimes does not equate to a similar size enclosure in a 4th order with more drivers

[Brian Steele]

slacker jack actually tapped horns are totally different topic

they looks like this

That's a low frequency TH - looks like 30 Hz or lower.

A 40 Hz TH might work better for a car, and be a lot smaller (horn length will be a lot shorter).

i heard one already but i find the size of the enclosure sometimes does not equate to a similar size enclosure in a 4th order with more drivers

They will be bigger, but also more efficient, with a better passband. They're closer to 6th order BP than 4th order BP.

[infinite_RPM]

they use rear loaded horns:

Were those properly-designed, or did the builders "try a ting"?

Rear-loaded horns require drivers with high Fs and low Qes and are not known for their low bass capabilities (there's a direct link between not only horn length, but mouth size and low frequency capability). A properly-designed tapped horn of the same volume will give better low bass at the expense of output around 100 Hz or so, primarily because the mouth size can be a lot smaller.

tried a thing lol.....those rear loaded have a very small bandwidth which they could play... was gona try the TH but the folding of the horn was getting me annoyed and i jus never got around to finishing it....Now that i have time i gonna try and finish it... any pointers?

[Brian Steele]

those rear loaded have a very small bandwidth which they could play... was gona try the TH but the folding of the horn was getting me annoyed and i jus never got around to finishing it....Now that i have time i gonna try and finish it... any pointers?

If you can fold a RLH, you can fold a TH . The only things different toyou're doing is (1) removing the rear chamber (though there are some TH designs that include this - IMO it just makes the design more complex than it needs to be) and (2) moving the driver into the horn itself. Google "fury box" for an example of a way how to do it.

[pugboy]

Coincidence,
I just built one for kicks, I just built a box that somebody already designed for a particular driver, it probably is not optimized for mine (12" Deltapro)
but it is playing quite loud and good to 40hz, not much below but very loud above.


This is the second one I built, the first was Danley TH-SPUD clone, its the big one in the background.

Tapped horns are getting a lot of interest over the last few years, more than any other speaker methodology especially since ported and bandpass techniques are over 50 years old.

Everybody is using the Hornresp program, its been pretty much proven to be quite accurate in modelling and predicting responses, if you check the diyaudio forums there are plenty scientists over there who have built and measured with their fancy test equipment. A guy over there built 4 boxes using 15"'s and says people can feel them a couple football fields away.

I am presently playing the Hornresp program and gonna try doing a proper box.

[Brian Steele]

This is the second one I built, the first was Danley TH-SPUD clone, its the big one in the background.

Nice job there. Response might be a bit wobbly in the passband though if the Deltapro's specs are significantly different to the driver used for the original model. What design did you copy?

BTW, is that a Lowther in the background?

Everybody is using the Hornresp program, its been pretty much proven to be quite accurate in modelling and predicting responses, if you check the diyaudio forums there are plenty scientists over there who have built and measured with their fancy test equipment.

Yes, HornResp is a good tool. It doesn't include losses in its model though, which probably needs to be taken into consideration (losses will reduce any response ripple, but may also increase F3 and reduce efficiency a bit).

[pugboy]

box I built is
http://www.freespeakerplans.com/mth-30.html
the path length is about 7ft which more or less corresponds with the 40hz

I was going to build this one but didnt bother
http://forum.speakerplans.com/thmini-ta ... page6.html

The driver in the back is a Fostex 206e fullrange in a Sachiko double backloaded horn.

As you can probably figure out I like to build boxes for kicks.
I usually end up giving them away cheap.

I have been building boxes for a very long time, I started measuring t/s parameters in the early nineties and experimented with building proper ported boxes then as opposed to "tryin a thing"

If I had access to the right 15"s I would be tempted to build a serious tapped horn just to see how they really compare to scoops/eaw at that level.

[Brian Steele]

box I built is
http://www.freespeakerplans.com/mth-30.html
the path length is about 7ft which more or less corresponds with the 40hz

The Delta Pro looks like it might be a pretty good match for that design, with its 51 Hz Fs. Only issue I see is the somewhat low Xmax (4.6mm), which would limit peak SPL.

What's the dimensions of that box? I was able to come up with a 6.8 (net)cu.ft. TH for the Delta Pro that would do 100dB/1W/1M all the way down to 50 Hz and about 93dB @ 40 Hz, but your box seems a bit smaller...

[pugboy]

this box is 24x27x13.5 about 5 cu ft

You have the Hornresp parameters ? I am trying to play with it also.

[Brian Steele]

this box is 24x27x13.5 about 5 cu ft

You have the Hornresp parameters ? I am trying to play with it also.

Not from that box, but I think they're quoted in the thread that associated with the design you tried.

I came up with the following:

Horn:
S1=203
S2=280.56
S3=1312.44
S4=1500
L12=L34=25
AP=525
VTC=2446.30 (a guess)
LPT=2.54

Driver:
SD=532.40
CMS=2.02E-04
MMD=41.15
RE=5.71
BL=15.44
RMS=2.04
LE=0.84

[DJ Q]

Won't mind trying this in my car... pugboy... lemme know when you're ready to give away

Would a tapped horn work all the way down to say 27 - 30Hz?

[SR]

downside to this

overal external dimensions in most cases will not fit a standard car trunk

[DJ Q]

Well I was going with the case that:

24x27x13.5

...was average.

[Brian Steele]

Well I was going with the case that:

24x27x13.5

...was average.

The dimensions will depend on the cutoff frequency for your TH and the driver's parameters.

For example, it is possible to design and build a 30 Hz TH that will fit in a car's trunk, but you may have to settle with using a smaller driver than you'd prefer to use.

For "Gallery Style" bass, I wouldn't aim for 30 Hz anyway. I'd start around 40 Hz, if not higher.

[DJ Q]

for the very least I'd want about 33-35Hz

what size driver(s) would work in that enclosure AND fit in a regular trunk?

[Brian Steele]

for the very least I'd want about 33-35Hz

what size driver(s) would work in that enclosure AND fit in a regular trunk?

If you're aiming for that type of Fb, I'd suggest start looking for a 10" or 12" with mid Q and Fs around 45 Hz, then start modelling to see if the box size can be made small enough to fit in the trunk without excessive compromises having to be made.

[pugboy]

I'll take a look at those HR figures, might have questions for you.

[Brian Steele]

TH POC#2 here http://www.diysubwoofers.org/projects/other/PA310-TH/

Driver is a $75 Dayton 12" pro audio driver. I made a couple of mistakes in the design/build (which led to this thread - http://www.diyaudio.com/forums/subwoofe ... youts.html), so I'm going to take another try at it in a few weeks (POC #2.1 ). The result was still loud enough to loosen the dust from my living room's ceiling when fed about 100 W or so, unoptimized and all. The design is partly "digitized" or "stepped", i.e. the expansion occurs in a series of steps after the first fold. Typically this is inconsequential as far as bass horns are concerned, as any resulting variations in the response will occur outside of the passband.

[ruffneck_12]

going slightly off topic

does the red design qualify as a tapped horn?

[Brian Steele]

going slightly off topic

does the red design qualify as a tapped horn?

Probably not.

[ruffneck_12]

but for a outdoor application, will the red design will be heard at a further distance/more 'spreading' of the sound than the blue design considering that both boxes have the same specs?

[- Rovin's car audio -]

im not a expert on this horn thing but to me that red design just looks like a normal ported box with 45 degree corners & a slanted front - dunno if there will be any benefits from just a slanted front .....

[kurpal_v2]

Might get some sort of loading effect on the straight wall....

[meccalli]

Tapped horns really work by shifting the phase of the speakers back wave(if so aligned) i believe 180 degrees(not sure) in order to couple with the front wave and therefore reinforcing the output. Generally if you dont have space to spare or know what you are doing, stay away from exotic horns or exotic enclosures in general. you are bound to design a better system if you already know proven designs well. A rear loaded horn is the most common in car situations but require massive area. Small bass horns have wacky responses...hell, even normal ones do. Hornresp is definitely a must if you want to try it. JBL has done a similar design with tapped horns/check out the Jensen Transflex as well.

[carfreak1024]

but will using this kind of system with a single 12" subwoofer, be greater in output than a properly designed ported enclosure with 2 10" woofers if you have enough power to power the pair of 10" woofers.

I mean at what point does the benefit of having a single subwoofer in a large TH enclosure stop making sense and having 2 of the same sized woofers in the same sized ported enclosure sound better.

The only experience i have had with building horns or anything is with my uncle when he used to DJ and building a scoop, but he always had a kind of guidline that said for this size of subwoofer, you need this kind of specs. But those boxes were always HUGE, i mean he rell struggle to fit the pair in the back of the Isuzu Trooper he had, and that van was rell big. and these scoops were for just 12" woofers BTW.

[Brian Steele]

but will using this kind of system with a single 12" subwoofer, be greater in output than a properly designed ported enclosure with 2 10" woofers if you have enough power to power the pair of 10" woofers.

It's a good question, and in fact I've posted exactly the same question on another forum.

In the specific instance of my POC #2 TH, this $75 driver driven by about 125W or less in a 4.1 cu.ft. (net) box is louder than my two Infinity 122.7Ws driven by 250W each in a 3.2 cu.ft. (net, stuffed) box. Well, down to the cutoff frequency .

I mean at what point does the benefit of having a single subwoofer in a large TH enclosure stop making sense and having 2 of the same sized woofers in the same sized ported enclosure sound better.

If you want to get the most out of a particular driver and amp, and have some space to spare, a TH may do the job for you. If you want to get the most out of the space available, and you've got money to spare on drivers, amps, cables and likely an alternator upgrade and batteries, going vented might be better - but you might end up being embarrassed by a guy with a $75 driver in a TH driven off a 100W amp

The only experience i have had with building horns or anything is with my uncle when he used to DJ and building a scoop, but he always had a kind of guidline that said for this size of subwoofer, you need this kind of specs. But those boxes were always HUGE, i mean he rell struggle to fit the pair in the back of the Isuzu Trooper he had, and that van was rell big. and these scoops were for just 12" woofers BTW.

Rear-loaded horns, or "scoops", are close relatives to THs, but not the same. They need to be huge, as cutoff point is set by path length AND the size of the mouth. THs perform well with much smaller mouth (and therefore net volume) requirements.

[infinite_RPM]

What about tapped tlines?