My small listening room has a low front wall due to sloping ceiling, it's kind of not usable for anything. The "waste of space" is marked on the image 1.1m from the front wall.
I had this weird idea, would it be possible to build a large bass horn by using the existing room shape (Yes), and then building multiple entry horns on the outer flares of the bass horn as an permanently installed stereo system/listening room So basically some kind of experimental multiple entry bass horn room.
Is it obviously impossible or just crazy enough idea that it might work?
I have basically unlimited freedom to experiment with the room/sound, as long as I don't destroy the house. So please talk me out of this, or encourage me to build it!
I had this weird idea, would it be possible to build a large bass horn by using the existing room shape (Yes), and then building multiple entry horns on the outer flares of the bass horn as an permanently installed stereo system/listening room So basically some kind of experimental multiple entry bass horn room.
Is it obviously impossible or just crazy enough idea that it might work?
I have basically unlimited freedom to experiment with the room/sound, as long as I don't destroy the house. So please talk me out of this, or encourage me to build it!
A bass loading horn is going to need free sides because a room wall doesn't support a growing rate of expansion.
I probably didn't explain the idea clearly enough. I would modify/ build the entire front of the room as the horn, not expecting to use the room shape as it is shown in the image. The rooms existing shape would be "just" the enclosure for the horn, so to speak.
Of course there will be room mode/acoustic problems added on top of everything.
Of course there will be room mode/acoustic problems added on top of everything.
I have a working knowledge of using the room itself as a horn. The type of horn you want to build makes an important difference.
Exciting project, I will follow with interest.
I've always wanted portability from my systems. Sure enough we did move from a custom room extension we built to a loft room.
You could use the 'unusable' space by filling it with suitable horns that fit the space but are not built in.
Tapped horns etc and enormous MEHs could shoehorn in nicely🙂 but retain moveability.
I've always wanted portability from my systems. Sure enough we did move from a custom room extension we built to a loft room.
You could use the 'unusable' space by filling it with suitable horns that fit the space but are not built in.
Tapped horns etc and enormous MEHs could shoehorn in nicely🙂 but retain moveability.
Not impossible, but the boundary reflection of the bass horn some distance from the .86 tall wall will tend to cancel some of the horn gain.
The boundary gain from front loaded subs mounted in the corners may approach the net horn gain unless the horn exit is the full width of the room.
You can calculate Speaker Boundary Interference Response (SBIR) with this calculator:
http://tripp.com.au/sbir.htm
Worth measuring output in your preferred listening position with the possible horn exit placements before proceeding.
Art
Something similar semi-permanent build I had in mind. I already have all the wooden parts ready for the Hinson meh's, still waiting for the speaker elements and amps. The problem I see with my idea is that the L&R MEH's would be located at the mouth of the bass horn/s, so kind of taps positioned inversely to wavelengths.
I've taken quite a bit of measurements as I've fine tuned the room treatments and speaker placements. I currently have a Genelec 7360 sub in the front of the room, which gets a hefty boundary gain for the lowest octave +9dB @ 19Hz, +12dB @~39Hz (1st axial mode). At the listening position the front sub(s) all have cancellations from ~65hz upward, combination of room modes and SBIR/LBIR. I've tried this with 1-3 subs in different locations on the front wall ie. half point, 1/4, 1/3, corners+mid wall and several combinations of these, including different heights.
I've raised the crossover fq since this OSM measurement to 90Hz, with side subs it works a lot better for filling the wide dip in Main L&R (55-80Hz) and the front wall sub, at the same time producing low frequency auditory envelopment based on David Griesinger's and Thomas Lund's presentations. This setup is the most balanced I've found, but the front sub is too small and upgrading that was what lead me to this topics idea.
Current placement is shown in the image below.
L&R: B&C 15cxn76 in 134l(net) bass reflex
L&R stereo subs: Eminence LAB12 in 32l(net) closed enclosures
Front sub: Genelec 7360
This room is my playground devoted to audio. I have a shallow understanding of acoustics but I'm completely newb when it comes to designing/building speakers, especially horns.
Do you think that with the boundary gain already provided by the shape, the large horn might be a bit of unnecessary complication compared to just a bigger BR or closed sub on the front? I'm not after high SPL but deep and balanced quality sound.
Thanks all for your insights!
Your room is kind of working for you already. You'll be fine putting a woofer half way up the wall (you'll need others beside it at the same height).
What you need to know is that it's only good to 200Hz. To go higher you'll simply need more woofers to spread around on the small wall, but they could also be smaller.
What you need to know is that it's only good to 200Hz. To go higher you'll simply need more woofers to spread around on the small wall, but they could also be smaller.
Last edited:
Yes, I think a large horn is an unnecessary complication if you are not after high SPL and want deep and balanced quality sound.
A large bass horn could offer higher efficiency with fewer drivers, which has nothing to do with sound quality unless amplifier power is limited.
Thanks @AllenB for sharing that Ripple tank image, I've used that to visualize other acoustics related concepts but never thought that it could be used to approximate this also.
Amp power is kind of limited. The house is old and can get uncomfortably hot during summer and I'd like to avoid adding more heat sources. This whole idea is so ridiculously excessive that I might have to experiment just for the sake of experimenting...
If your get your MEHs LF to play down well below 100Hz, I'm not sure that would matter..
I've found to below 60Hz, ideally 50/55 great when integrating with my tapped horns.
Above 55Hz the tapped horns are there with enough dB, but a bit too polite for my taste these days🙂
If you have time the bass and MEHs for best sound, perhaps it will work well.