Horn-loaded port.

[Circlotron]

Does anyone here have any experience with a bass-reflex system that uses a horn at the outer end of the port? Particularly retrofitting a horn to an existing system.

Maybe even a horn on *both* ends of the port. That'd be interesting.

[roddyama]

Hi Graham,

That imagination of yours never takes a rest does it?

Using a horn for a port would be similar to using a flared port. The horn would be too small to have any real effect at the operating frequencies of the port.

[till]

No port with horn, but not far. My Altec A7 like Loudspeakers as far as i understand are portet boxes below ca. 150Hz. These speakers are not really famous for bass response. Measurement of the box standing free in room shows something like bass from 60Hz up. Placed in the rooms corner (= horn) i have bass form about 40Hz upwards. So i think about building a room with 2 suitable corners to avoid subwoofers.

http://home.tu-clausthal.de/~tpa/VotT/IMAGE0056.JPG

[Circlotron]

Originally posted by roddyama
Using a horn for a port would be similar to using a flared port. The horn would be too small to have any real effect at the operating frequencies of the port.

I'm imagining using a BIG flared port, maybe 1 or 2 metres long. Actually, now I think of it, the speaker box would be like the compression chamber, only much bigger than usual.

What I really want to do is put a big funnel on the port hole of my sub to get super-duper efficiency over a necessarily limited range of frequencies. Or should I just shove it over the front of the driver instead? Or have both the driver *and* the port hole talking into the small end of the horn?

/Circlotron - making horn experts groan for sure.

[Volenti]

Originally posted by Circlotron

Or have both the driver *and* the port hole talking into the small end of the horn?

/Circlotron - making horn experts groan for sure.

I would try this first, from my experience in car audio, where many vehicles effectively horn load the subwoofers and vented enclosures have high efficiency there.

I would also initally set the port tuning frequency a bit higher than you would in a standard vented box, also from my experience in car audio, assuming you will be making a pretty large horn.

[Centauri]

I'm imagining using a BIG flared port, maybe 1 or 2 metres long.

Starting to sound like a rear-loaded horn cabinet......

Cheers

[mikee12345]

http://www.decware.com/wicked1.htm

1m horns are not bass useful.

not a horn but a waveguide

how would you calculate it? youd have to use horn software as a p ort cant be expanding like that and still be calculated.

Like a giant vero-vent the chambers are allowed to breath through the carpeting altering the impedance curve on the fly to enhance efficiency, and more importantly create a sympathetic diaphragm out of your floor!

[zobsky]

Originally posted by Circlotron

I'm imagining using a BIG flared port, maybe 1 or 2 metres long. Actually, now I think of it, the speaker box would be like the compression chamber, only much bigger than usual.

What I really want to do is put a big funnel on the port hole of my sub to get super-duper efficiency over a necessarily limited range of frequencies. Or should I just shove it over the front of the driver instead? Or have both the driver *and* the port hole talking into the small end of the horn?

/Circlotron - making horn experts groan for sure.

isn't that what a rear loaded horn speaker does (the front radiates sound directly at the user and the rear picks up the efficiency [usually of the lower frequencies] by channelling the rear wave through a horn guide)?

[roddyama]

A port in a BR type system operates on a different principle than a horn. A horn is an acoustic impedance transformer. The horn serves to increase the acoustic impedance on the compression driver so it can more effectively deliver its power to the room. A port holds a mass of air that resonates when excited at a particular frequency (tuning frequency) against the “spring” of the air in the box.

I’m implying that this idea won’t work, just that there are two different principles at work here.

[Ilianh]

Its interesting how this morning I was thinking the exact same thing.

I'd suspect someone good with double BR boxes (MJK has a worksheet for them) could help on this one.