How big a Khorn to reach 20Hz?

[Colin]

The classic Klipsch corner Khorn goes as low as 30Hz without any apparent effort, giving it a lean, but very natural sound. The question is, with the bass bin already huge, how much larger would the bin have to be for Khorn bass to extend down to 20Hz?[:^)]

[DrWho]

I've thought about this as well....a two or three piece khorn (one

piece similar to the original, and then other pieces to finish out the

flare down to 20Hz only because a single piece wouldn't fit through the

door). I don't think the original khorn could be modded to do this

though; as in I think a new driver and new flare rate would be needed

(also requiring a midhorn that digs even deeper, which then means a

tweeter that digs deeper too). Perhaps a 4-way speaker would be in order.

I believe the horn would have to have a mouth somewhere around 8'x8'

(so we're talking a huge room too and a floor to cieling

speaker)...though it would be kinda cool to have a bass horn that uses

the floor and cieling of the room - with the proper time alignment it's

bound to sound good.

[Colin]

so not merely another fold, or 20% taller, or another foot wider?

what about making it twice as high?

[colterphoto1]

Too big to fit through a door. That was actually a limiting factor in the original Khorn design, per Trey. One of the dimensions had to easily fit through a normal residence doorway.

Michael

[boom3]

Scaling horns up is not merely an excercise in mathematics; for a bass horn, the folding geometry would have to change. Changing the folding scheme affects the upper bass/lower midrange as well. Then there is the matter of the room itself supporting a 20 Hz wave. Most domestic living rooms don't do a very good job, due to size and flexure of walls windows, doors and floors. However, if we use the auto cabin model, a tightly sealed room with more rigid boundaries would allow one to sit in the pressure domain of the wave. The current HT crowd won't go for this sort of remodeling.

I'm not sure I would want a bass horn to go to 20 Hz. There is very little (some say no) musical information below 32 Hz even on the best recordings, and trying to reproduce the acoustic 'trash' below that point introduces more distortion of all kinds. If you want to reproduce sound effects, buy a subwoofer, and keep your Klipsch Heritage speakers for the other 99% of the music.

[formica]

There is very little (some say no) musical information below 32 Hz even on the best recordings, and trying to reproduce the acoustic 'trash' below that point introduces more distortion of all kinds.

I'd have to disagree with that... especially on modern recordings. Turning off my subwoofer makes this readily apparent. Obviously I'm not referring to classic rock from the 60s which was recorded with vinyl's limitation in mind. The difference between a 40Hz and 20Hz is a full octave.

I do agree that scaling up the Khorn does drastically change the design and force a four way design. The EV Patrician comes to mind, which, unfortunately it didn't improve the lower Fc very much while it significantly reduced it upper range.

Some horn guru could provide more details.

Rob

[ZAKO]

Formica....What music do you play that goes down to 20hz ??? I have some orgeon music that trips 25hz but who cares. You still need a large room.

[DrWho]

to name a few: About 30% of Nightwish and Ayreon, about 10% of

Avantasia...I know a lot of Dream Theatre digs pretty low as well. And

then there is CellDweller too. I have some "German Techno" that hits

down about 16Hz. So basically all the modern (not mainstream) rock will

have subharmonic material at some point. And yes, it makes a huge

difference to the enjoyment of the music when you take it away.

Btw, room size has nothing to do with a "lowest frequency" you can

hear. Another one of those audio myths that seems to float back to the

top every once in a while.

[Nklipsch]

we all want 20hz-20khz but is it really required? I find ~32hz a decent cutoff for music,I listen to DnB.

A 650litre labhorn sized unit will only reach ~27hz in room. With a 1.2m flare extender it will go a little bit lower.

http://www.geocities.com/xobt/basshorns/basshorns.htm

http://web.archive.org/web/20000610064936/http:/www.arl.mil/ARL-Directorates/ISTD/aat/MOAS.htm

[DrWho]

we all want 20hz-20khz but is it really required? I find ~32hz a decent cutoff for music,I listen to DnB.

A 650litre labhorn sized unit will only reach ~27hz in room. With a 1.2m flare extender it will go a little bit lower.

http://www.geocities.com/xobt/basshorns/basshorns.htm

http://web.archive.org/web/20000610064936/http:/www.arl.mil/ARL-Directorates/ISTD/aat/MOAS.htm

And with 650L you can get a lot more sub by going with direct

radiators...namely more sensitivity / less cone movement - thus

negating the biggest benefit of hornloading (not to mention the

other compromises associated with hornloading).

I'll just stick to my IB subs (once I get a house of course) []

[formica]

Formica....What music do you play that

goes down to 20hz ??? I have some orgeon music that trips 25hz

but who cares. You still need a large room.

I'm into mostly alternative industrial influenced styles like

Industrial Metal, Industrial, EBM, Drum-n-Bass, Tripp-Hop, experimental

techno, etc... but the heavy bass signals are limited to those

styles. You'll find some good 20 to 25Hz signals in international

music like Kodo or Blue Man Group ... as well fusion artists like

Victor Wooten and Bela Fleck & The Flecktones.

When you compare this to the Cornwall I... which is rated to 38Hz

with ±5db add to the fact that its probably rolling off at 24db per

octave... you are missing almost a full octave. Is it me, but

that sounds like something John Warren would say? [:|]

Colin: if you really want to model a 20Hz horn you could download

Hornresp program at http://www.users.bigpond.com/dmcbean/ and plug in

some numbers. I would be huge even in 1/8 space... but I rather

leave exact mouth sizes to horn gurus l...

Rob

[Nklipsch]

And with 650L you can get a lot more sub by going with direct radiators...namely more sensitivity / less cone movement - thus negating the biggest benefit of hornloading (not to mention the other compromises associated with hornloading).

I'll just stick to my IB subs (once I get a house of course)

Not all of us have an attic that we own to cut holes into :-)

Actually,I disagree. Try it. For $/dB horn is the best anyway. I wont bother comparing 14 x 8"s to the six 12" business.

Im not advocating compromised pipe horns for 20hz,I think that sticking horns to an octave higher is a more practical idea,eg edgar horns.

edit : we both own 2226 for sub duty :-)

Mike.e

[DrWho]

$/dB I think it comes out to about the same...but I guess it depends on

your goals. Mounting four $300 drivers in the cieling doesn't cost too

much beyond the cost of the drivers (so let's call it $1500) - I bet

you could easily drop $1500 on a huge bass horn (a sheet of plywood

costs like $40-$80 depending on how nice you want it - multiplied by 10

is pusing $600, then add a $300 driver which comes to $900 and then a

few hundred for finishing and nails and all that). I think the few

hundred dollar difference makes up for itself when you take into

account the amount of floor space you save (perhaps we should include

the average price per square foot of our houses too) []

[D-MAN]

This 2-page article about a 25Hz horn might clear some things up...

It should indicate the impracticality of a 20Hz horn, that's for sure!

DM

[D-MAN]

page 2 of 25hz horns article.

DM

[formica]

I was wondering when you were going to reply...

This 2-page article about a 25Hz horn might clear some things up...

Looks like it could be interesting if we could actually read the text... Think bigger... [:|]

[Nklipsch]

$/dB I think it comes out to about the same...but I guess it depends on your goals. Mounting four $300 drivers in the cieling doesn't cost too much beyond the cost of the drivers (so let's call it $1500) - I bet you could easily drop $1500 on a huge bass horn (a sheet of plywood costs like $40-$80 depending on how nice you want it - multiplied by 10 is pusing $600, then add a $300 driver which comes to $900 and then a few hundred for finishing and nails and all that). I think the few hundred dollar difference makes up for itself when you take into account the amount of floor space you save (perhaps we should include the average price per square foot of our houses too)

4 15"s in the ceiling wont acheive the same SPL. Their sensitivity will be about 90dB/1watt vs 105dB/1watt for the one hornloaded driver.. Ofcourse the sealed box response will roll off nicely to give about 80dB/1watt at 20hz.

I wouldnt use ply,its not going to move.

For the LF I wouldnt consider basshorns,they approach ROOM size.. For the midbass,yes. Most of use dont need it that loud anyway.

Apples vs oranges. Would be cool to integrate it with the design of a new house though!

[TBrennan]

I used this array of JBL 4648s to augment Altec A5s below 100hz. Efficiency was 103db, distortion was very low and dynamically they kept pace with the Altec basshorns. With a some EQ (6db at 30hz) these were flat down to 25hz.

I see no need for basshorns to go this low if one is going to use a large array of direct-radiators like this.

[WMcD]

Hey D-Man. I'd like to read the article too. It would be nice to have a bigger scan.

I would not say that the K-Horn gets to 32 Hz (or so) without any problem.

The bass horn has a flair of Fc=48 Hz. The resonance of the driver is down around 35 Hz.

The article on the Jubilee shows that in an outside corner, both have fairly poor bass response, though the Jubilee is better. Naturally it is room gain, and perhaps the presense of two bass horns, which make up for the roll off.

I've also posted articles from a French magazine about the K-Horn. The graphs seem to show this too.

It might be that a variation on the Jubilee with drivers with a low Fs and / or a passive radiator could get to 20 Hz in the right room. Maybe.

Gil

[D-MAN]

Guys, I have to apologize, I don't have any other copies but those posted which are too small to read. I didn't know it at the time.

As far as the Khorn expansion rate, here is an except from a 1957 Klipsch brochure. See the "boxed" area. As another point of Khorn Konfusion, PWK states the "current horn" (assumed to be the Khorn) in the Jublilee paper has an expansion rate of 38Hz!

DM