Corner-loaded bass horn designs other than Khorn?

[mark1101]

Here's the MCM in 4 way with subs this time. HF curve has been flatened as well.

[djk]

Looks pretty good, how was the speaker measured? Indoors, outdoors, 2Pi, 1Pi, or .5Pi?

[seti]

Seti, lookin'good. That must sound pretty good bro.

Thanks they sound awesome with alot of help from you, ibslammin, jwc, maron, and that crazy horn builder.

[djk]

"I've heard that tapped horns go very, very low, but that they trade this
depth for a loss in efficiency. Is this right? "

No, look at the graph of the 4015LF2, it's 108dB/2.83V/1M in 2Pi, and ±2dB from 31hz~150hz.

Actual measurements of the single sheet TH challenge box:

40hz 98.5

45hz 100.5

50hz 102

55hz 103.5

60hz 105

65hz 105

70hz 105

75hz 104.5

80hz 104.2

85hz 104

90hz 104

95hz 104

100hz 104.5

105hz 105

110hz 105

115hz 105.5

120hz 106.5

A conventional horn CANNOT compete (unless much larger).

Compare with a BFM tuba of the same bulk

http://www.prosoundshootout.com/Measurements/Tuba24_28v.gif

How about the much, much larger Titan 48?

[djk]

"Love the chart for that dual 15" corner horn! Do you have drawings
or pics of it?"

I would lay it out someting like this:

This is similar to the 30W version of the EV patrician, and about as simple a way to build a cornerhorn as there is. With solid walls extending another 2'~3' beyond the box it should perform close to the computer model.

"Is the K44E still availble? How is it different
from the standard 33?"

It has a 3" coil and a 95oz magnet. You would have to contact Klipsch about availability, they may have a better driver to recommend.

[psg]

"Yes, I was. I hadn't actually seen a frequency response curve. I liked
the relative ease of build and have a spot for a La Scala sized sub.
Do any of the Tuba builds measure well if you consider only up to 80 Hz
(or less)? "

"This is the (advertised) curve"

The pro sound shoot-out I posted the Tuba 24 graph from has also posted several of his other designs. None of them measure as advertised.

A tapped horn is much better than a small conventional horn. jbell has a one 4 x 8 sheet tapped horn challenge going on over at DIY audio, any of them would be preferable to a BFM design, and be easier to build. Here is a 2' cube entry:

http://www.diyaudio.com/forums/subwoofers/127908-jbells-set-four-tapped-horns-41.html

Very interesting thread over there!

Forgetting about the Tuba 24 (since I meant the Tuba HT) what is a recommended easy build for low end extension? say to 20 Hz? I don't need anything over 80 Hz for home theater (and as a sub for Klipschorns). A Spud?

Is there a real measurement of the Tuba HT somewhere?

Thanks!

[mark1101]

The MCM system was measured in room each driver individually from 3 ft. away using pink noise. The dip at 177hz is a Klipsch spec'd PEQ setting. I don't know what's up at 500hz, but both XII mid-bass modules do the exact same thing. No EQ on those XII modules. The HF drivers are TAD 4002 and they are flat as a razor. It might look like I have the system tilted toward too much bass but it has tons of top end. Sounds very balanced.

[Olorin]

"Yes, I was. I hadn't actually seen a frequency response curve. I liked
the relative ease of build and have a spot for a La Scala sized sub.
Do any of the Tuba builds measure well if you consider only up to 80 Hz
(or less)? "

"This is the (advertised) curve"

The pro sound shoot-out I posted the Tuba 24 graph from has also posted several of his other designs. None of them measure as advertised.

A tapped horn is much better than a small conventional horn. jbell has a one 4 x 8 sheet tapped horn challenge going on over at DIY audio, any of them would be preferable to a BFM design, and be easier to build. Here is a 2' cube entry:

http://www.diyaudio.com/forums/subwoofers/127908-jbells-set-four-tapped-horns-41.html

Very interesting thread over there!

Forgetting about the Tuba 24 (since I meant the Tuba HT) what is a recommended easy build for low end extension? say to 20 Hz? I don't need anything over 80 Hz for home theater (and as a sub for Klipschorns). A Spud?

Is there a real measurement of the Tuba HT somewhere?

Thanks!

A SPUD is good, and so is the Lab12 tapped horn, and so is the Volvotreter 20 Hz tapped horn here and here. The Lab12 and VT tapped horns have the advantage of being open source and may or may not be a friendlier form factor than the SPUD, depending on your space.

[Lime Twig]

"I've heard that tapped horns go very, very low, but that they trade this
depth for a loss in efficiency. Is this right? "

No, look at the graph of the 4015LF2, it's 108dB/2.83V/1M in 2Pi, and ±2dB from 31hz~150hz.

Interesting. So what's the trade-off? If TH are highly efficient, go lower, are smaller, and easier to build, what do they give up?

and thanks for the corner horn sketch! I was wondering if one could modify the MWM design to increase the flare to 90 degrees and make full use of the corner. Have you built this one before?

[Olorin]

"I've heard that tapped horns go very, very low, but that they trade this
depth for a loss in efficiency. Is this right? "

No, look at the graph of the 4015LF2, it's 108dB/2.83V/1M in 2Pi, and ±2dB from 31hz~150hz.

Interesting. So what's the trade-off? If TH are highly efficient, go lower, are smaller, and easier to build, what do they give up?

and thanks for the corner horn sketch! I was wondering if one could modify the MWM design to increase the flare to 90 degrees and make full use of the corner. Have you built this one before?

They are tapped quarter-wavelength resonant enclosures, so low frequency extension still means big boxes. They don't go lower for the same enclosure volume than other designs, and they are not necessarily easier to build. They have a narrow usable bandwidth, usually less than three octaves, and you almost always need a low-pass filter to prevent overexcursion when the driver unloads at the corner. Their ONLY advantage is that, when properly done, they are very efficient in their passband. Hoffman's Iron Law is still made of iron.

If you're really interested in tapped horns, it's worth your while to invest some time in the collaborative tapped horn thread at diyaudio.com. Bring lunch; you'll be there for a bit.

EDIT: Not low pass filter. HIGH PASS filter. Duh. Thanks for the catch, psg.

[Lime Twig]

They are tapped quarter-wavelength resonant enclosures, so low frequency extension still means big boxes. They don't go lower for the same enclosure volume than other designs, and they are not necessarily easier to build. They have a narrow usable bandwidth, usually less than three octaves, and you almost always need a low-pass filter to prevent overexcursion when the driver unloads at the corner. Their ONLY advantage is that, when properly done, they are very efficient in their passband. Hoffman's Iron Law is still made of iron.

If you're really interested in tapped horns, it's worth your while to invest some time in the collaborative tapped horn thread at diyaudio.com. Bring lunch; you'll be there for a bit.

I've been reading over the thread. It's interesting. I'm always a bit suspicious when I encounter a new (to me) design which seems to promise all the answers! Thanks for filling me in on the (inevitable) trade-offs.

What I really want to know more about is their sonic character. I need something that will mate well with my La Scalas. To me, that means I want a sub with real snap, so I can hear the strike of the bass drum that gives dance music it's character. That's one feature that all the good club systems have in common. The more reading I do, the more I realize I don't need (or even want!) a sub that goes to subterranean depths, what I need is one that will match the La Scalas fast, snappy horn sound. Can anyone tell me their impressions of a tapped horn's sound compared to a conventional folded horn?

[djk]

"and thanks for the corner horn sketch! I was wondering if one could modify the MWM design to increase the flare to 90 degrees and make full use of the corner. Have you built this one before?"

That drawing is basically an MCM designed for a corner.

This design was quite popular in the midwest about 30 years ago. Used for live music, it usually had a single JBL K151 loaded, and was intended to be used with 'barn doors' (mouth extender wings). Most users ended up leaving the loading doors off for the woofer, and it behaved like a tapped horn/scoop hybrid.

[Lime Twig]

That drawing is basically an MCM designed for a corner.

I thought so. I'm wondering, you said earlier that you thought the MWM would be a bad choice for dance music. This design looks very similar yet peforms incredibly well according to the graph you posted. Where's the difference coming from?

Most users ended up leaving the loading doors off for the woofer, and it behaved like a tapped horn/scoop hybrid.

I'm missing something obviously, since I don't understand how it could be like a TH or scoop. Is the driver not in a compression chamber in this design?

[djk]

"I'm missing something obviously, since I don't understand how it could be like a TH or scoop. Is the driver not in a compression chamber in this design? "

By "leaving the loading doors off for the woofer", it's now open for the backwave to add to the front wave.

" This design looks very similar yet peforms incredibly well according to the graph you posted. Where's the difference coming from?"

The tri-hedral corner and the contour of the cabinet make the air path over 98" effectively vs the 72" path of the MCM. Plus, the wall greatly extends the mouth area, and completes the hyperbolic taper (MCM is exponential, hyperbolic will have better bass). Just placing an MCM in the corner will not yield the same results.

For in close bass, I don't like conventional horns, they feel like they have no bass. A tapped horn is not actually a horn in the range that we want it to work in, and does not suffer like a conventional horn does.

http://forum.speakerplans.com/near-and-far-fields_topic37512_post379068.html?KW=velocity#379068

http://forum.speakerplans.com/labs_topic12843_post121927.html?KW=velocity#121927

[John Warren]

This is similar to the 30W version of the EV patrician, and about as simple a way to build a cornerhorn as there is. With solid walls extending another 2'~3' beyond the box it should perform close to the computer model.

This gives some idea, the rear looking woofer loads a throat that expands upward then out thru the top front of the enclosure.

[djk]

I sold my 30W to an organ buff, interesting conversation piece.

[psg]

"Yes, I was. I hadn't actually seen a frequency response curve. I liked
the relative ease of build and have a spot for a La Scala sized sub.
Do any of the Tuba builds measure well if you consider only up to 80 Hz
(or less)? "

"This is the (advertised) curve"

The pro sound shoot-out I posted the Tuba 24 graph from has also posted several of his other designs. None of them measure as advertised.

A tapped horn is much better than a small conventional horn. jbell has a one 4 x 8 sheet tapped horn challenge going on over at DIY audio, any of them would be preferable to a BFM design, and be easier to build. Here is a 2' cube entry:

http://www.diyaudio.com/forums/subwoofers/127908-jbells-set-four-tapped-horns-41.html

Very interesting thread over there!

Forgetting about the Tuba 24 (since I meant the Tuba HT) what is a recommended easy build for low end extension? say to 20 Hz? I don't need anything over 80 Hz for home theater (and as a sub for Klipschorns). A Spud?

Is there a real measurement of the Tuba HT somewhere?

Thanks!

A SPUD is good, and so is the Lab12 tapped horn, and so is the Volvotreter 20 Hz tapped horn here and here. The Lab12 and VT tapped horns have the advantage of being open source and may or may not be a friendlier form factor than the SPUD, depending on your space.

Thanks! These are great! I hadn't realised that high-pass filtering was essential. I thought that you could just be careful with the source material and keep the volume down with ultra-low content. That adds to the expense a bit, and is something I know little about.

[Lime Twig]

For in close bass, I don't like conventional horns, they feel like they have no bass.
A tapped horn is not actually a horn in the range that we want it to
work in, and does not suffer like a conventional horn does.

Thanks for the explanations of increased horn length and how it fucntions as a TH.

I'm curious about your dislike of conventional horns though. I mean, there are obviously very different schools of thought in audio circles, but disliking folded horns tout court seems to fly in the face of all the most renowned club systems. Richard Long's original systems, Funktion One and Martin Audio's contemporary flagships, as well as the smaller "boutique" NY installers like Gary Stewart Audio and Systems By Shorty. They all use horns exclusively and are all renowned for their bass. Are you not a fan of these systems, or do they achieve something that you feel horns usually don't? Alternatively, perhaps you feel they aren't good examples of what you're describing here?

[Olorin]

A SPUD is good, and so is the Lab12 tapped horn, and so is the Volvotreter 20 Hz tapped horn here and here. The Lab12 and VT tapped horns have the advantage of being open source and may or may not be a friendlier form factor than the SPUD, depending on your space.

Thanks! These are great! I hadn't realised that high-pass filtering was essential. I thought that you could just be careful with the source material and keep the volume down with ultra-low content. That adds to the expense a bit, and is something I know little about.

Nice catch on the high-pass filter; I misspoke on that in my earlier post and have edited.

An HPF doesn't have to cost more than $100 -- you can do it with a BFD or DEQ if you can pass at 20 Hz or above, while the Behringer MIC-2200 can get you 24 dB at 15 Hz if you chain the inputs and the Reckhorn B2 goes all the way to 10 Hz.

[djk]

"'m curious about your dislike of conventional horns though."

There seems to be no bass close to them. Read the references in my previous post. Olson wrote about this more than 50 years ago.

"Richard Long's original systems,"

Used JBL 5420s on top of RCA Olson bins.

The 4520s are a scoop (back loaded horn), and act like a direct radiator above the bottom octave. The RCA Olson bins are open in the back, and are not a conventional horn.

"Martin Audio's contemporary flagships"

The flagship ASX (which replaced the GSA at MOS) is a hybrid ported horn.

"They all use horns exclusively and are all renowned for their bass."

MOS replaced the GSA "Big Bertha's" with ported horns to get better bass. The RLA and GSA were never horn loaded in the midbass region either (4520s)

"Are you not a fan of these systems,"

Which ones? The RLA with the Olson bins sounded better up close than the GSA with the "Big Bertha's", but I can't say I like a 4520 for midbass.

" Alternatively, perhaps you feel they
aren't good examples of what you're describing here?"

I'll wager the Martin system now in MOS that replaced the GSA system, with ported horns and horn-loaded midbass, sounds better.

Conventional horns sound OK in the bass if you're back 40' or so. Bass on the dance floor? I don't think so.

You are " I'm using to DJ small parties and we need bass.", that sounds like a "Big Bertha" type bass horn may not be what you want.

One of the worst dance club installs I ever heard was an MWM right at the edge of a very small dance floor, no bass, zip, nada.

If you could scare up a KP600 system it might be what you could use.

http://s259.photobucket.com/albums/hh297/dpbenson/?action=view&current=KlipschForum016.jpg