A 4-way Horn speaker

Hi , I am in the process of evaluating several different ideas for a Horn speaker system. The one concept that is my Favorite is similar to Tune Audio's Anima horn speaker. I like the idea of saving floor space and the (WAF) :D - of standing the bass horn upright with the mouth facing the floor. I'm not able to clone their exact horn of coarse , they don't list their drivers so my drivers and design will be a little different , they use a tweeter horn crossed over at 1500Hz , to an unknown 5 inch driver in their midrange horn, and cross it over at 250hz to their 15 inch driver in the upright bass horn with it's mouth facing down, and of coarse a sub woofer. I would really like to keep the same number of drivers and basic look of their design ... but I was really wanting use a driver for my midrange horn that needs to cross over at 400hz. My question is -- is the 150Hz difference between their crossover point of 250Hz and mine at 400Hz to much of a difference? I don't no much about bass drivers facing down verses your bass driver facing forward to know if that is too high of a cross over point? -- I realize the best way to know is to model and build it to find out , but the drivers I want to use for the midrange horn are about $1,400.00 a pair , Way too much money (to me) if I find out they won't work in that design! -- So I was hoping that someone here would be able to answer the question ??? Does anyone here know? - Thanks for any help you can give! - Dean
 
- Tune Audio , Anima Horn Speaker
IMG_4028.JPG
 
  • Like
Reactions: 2 users
diyAudio Moderator
Joined 2008
Paid Member
Opening to the floor would appear to be a discontinuity. The length of the horn at this point looks roughly about a half wavelength of 250Hz. I assume they were going to EQ this in the cross, and deal with 125Hz some other way. But then there's 375Hz...
 
Yes 400hz is too high to face down I would say. Even 250 is pushing it. The fundamentals of low human voice are down there. Imagine if a person was singing through a megaphone pointed at the floor, or pointed towards you. The sound would suffer much pointed down.

It is a beautiful speaker, but i always sctatch my head when people are building 4-5 way systems, since I am covering the full range with 2. Unless your room is a gymnasium I don't see a need for so many drivers and the coherency compromises they create.
 
  • Like
Reactions: 2 users
4-way + a subwoofer is necessary, I think.
1. Midwoofer will most likely be an efficient 12-15", which will not play much bass.
2. A large horn that is crossed at 400Hz will not sound as good as a smaller horn at 2000Hz.
3. And a smaller horn will not sound as good at 5000Hz and up as a dedicated supertweeter with almost no horn.
 
It is a beautiful speaker, but i always sctatch my head when people are building 4-5 way systems, since I am covering the full range with 2. Unless your room is a gymnasium I don't see a need for so many drivers and the coherency compromises they create.

This is about engineering compromises.
If you choose the higher efficiency and directional control of a true horn, you also get a maximum bandwidth of about 1 decade. Absolute Minimum of 3 way. Waveguides have higher bandwidths than true horns, but have other tradeoffs.

HTH
 
This is about engineering compromises.
If you choose the higher efficiency and directional control of a true horn
Also the direct radiating membranes ( commonly known as speakers :p)
exhibit the same characteristics, due to the phisical size( diameter-> pistonic behaviour) and geometry of the membrane ( more or less depth, conical, exponential profile or flat membrane...even convex )
 
This is about engineering compromises.
If you choose the higher efficiency and directional control of a true horn, you also get a maximum bandwidth of about 1 decade. Absolute Minimum of 3 way. Waveguides have higher bandwidths than true horns, but have other tradeoffs.

HTH

An excellent point. I'm getting neither the efficiency nor the directivity below 500hz, and directivity is falling quickly by 700. Which seems to me a good compromise, but certainly others disagree.

AllenB, I guess my megaphone example was a guess. But it seems logical and consistent with the generally accepted principle to not fold a front loaded horn path below about 200hz. I believe that's the frequency I've seen cited. Perhaps im wrong?
 
A gentle J-shaped bend can be achieved without being too destructive above 200 Hz. My horn for a compression driver that is crossed from 440Hz would have been 100 cm deep including the driver if I didn't bend it a little. The same same can be done for midwoofer horns. Question is where you want it to bend. Actually, the question is if you want it to even be a horn. I built both a JBL 2220H horn and a ported cabinet for JBL 2225H and liked the ported version better than the horn. A combination was even better, but it had a rather low WAF.
 
I'm a little out of my depth here and may not understand what you are saying so if i'm wrong please don't be offended - :) - but the Volti Vittora Horn's Bass horn is a folded horn that runs from 400hz to 50hz and is a wonderful sounding horn - it has many rave reviews and I just spent two days listening to it and love the horn system . The Living Voice Vox Olympian Horn system uses a folded horn from 300hz to 70hz , and it is considered one of the best commercial horn systems in the world. -- :confused: -- Best Regards, Dean
 
diyAudio Moderator
Joined 2008
Paid Member
It can be done, just carefully. The Volti looks like a bifurcated J horn, which as Rewind has said, can be a less harmful compromise.

I'll try explaining the resonance from my first post (assume the floor openings are equal in area to the cross section of the lower part of the horn, so there is no restriction at the exit).

The horn holds pressure, being a narrow duct. When it reaches the exit and the vast openness of the room, it dissipates quickly creating a relative vacuum at the mouth. This travels back up the horn and interferes with the signal from the speaker. This can cause peaks and nulls in the response at multiples of the lengths involved.
 
Hi , thanks Allen for the explanation , I understand now - not sure of how they solved the problem .... so I sent the question off to the designer of the Anima Horn - hopefully he or someone else here can explain how they solved the problem... :tilt:
- the Volti Vittora Bass horn is actually a W Bin , built in a similar way to the Klipsch LaScala Horn, but about twice the volume of the La Scala and much better built - many layers of 1/4 inch Baltic Birch Plywood are laminated with a two part permanent glue till it is an inch thick , and then placed over a curved form and vacuum bagged to the shape of the form to get the very strong curved shape he wanted.
The design for the w-Bin was farmed out to someone in Europe I believe -- then many different throat area designs were tried out of chip board till the over all horn designer Greg Roberts was happy with the sound he was getting from the new W-horn.
 
It may be my fault that I put us down a rabbit hole that may not be the most relevant to your question. If a carefully folded horn can sound good up to 400hz, that doesn't mean that it will be ideal if pointed at the floor. I'm guessing it isn't ideal.

Also as I mentioned, my 2 way loses directivity around 700hz, which is a compromise. The higher you cross to that downward facing horn the higher you will be losing directivity, which is a big reason for having such a complex system in the first place.

Also, right where you cross over, your dispersion is going to go from narrow on the front facing midrange
horn to 360 degrees on the down facing horn. If that happens at bass frequencies where the dispersion is 360 anyway (because that's how bass acts), then its fine, but at 400hz, that sudden change in directivity will not be ideal. I wish it were easy for me to flip my woofer section somehow to down firing. It would be a fun experiment to hear for myself just how much of a compromise it would be. I know it would require a level boost for the frequencies near the crossover, which would definitely alter the power response (the total sound at the listening position including both the direct from the driver and the muddier sound from the room reflections).

At any rate, horns are a blast. I'm glad you're starting down the road to building some. Sorting out these details is a very good learning experience for all of us. Craig
 
diyAudio Moderator
Joined 2008
Paid Member
to flip my woofer section somehow to down firing.
It's curious that there was recently a 'slot loaded' woofer trend here. Not convinced, I took a pair of 15" woofers in 3cu' boxes face down on the floor, sides facing forward, tops touching, and propped the fronts up on bricks (at the front only). There was a certain je ne sais quoi, very appealing, but there are so many possible explanations that I don't want to guess.

By the way, these drivers were closed box suitable, definitely not horn material. Crossed at 200Hz.
 
Last edited:
I had a listen to this system again today. BASSHORN XD - Avantgarde Acoustic Hornloudspeaker
TRIO XD - Avantgarde Acoustic Hornloudspeaker

Previously I found the basshorn a bit boomy, but today I asked them to increase the volume and it is just the lack of lower midbass from the Avantgarde Trio. The sound from the basshorn is crisper than a regular subwoofer, but not much detail is left after it has been folded several meters. So it behaves just like a regular subwoofer, with not much usable sound above 80-100Hz, just slightly more snappier och crisper, but maybe also muddled from having such a long folded horn. Someone can probably explain why, better than me.
The Trio itself is fine, I just prefer my version which can produce a full midbass without the help of a subwoofer/basshorn, crossed a little too high.
 

Attachments

  • 20190511_150039.jpg
    20190511_150039.jpg
    784.5 KB · Views: 918
  • 20190511_145528.jpg
    20190511_145528.jpg
    713.1 KB · Views: 912
Last edited:
  • Like
Reactions: 1 user
Member
Joined 2007
Paid Member
I had a listen to this system again today. BASSHORN XD - Avantgarde Acoustic Hornloudspeaker
TRIO XD - Avantgarde Acoustic Hornloudspeaker

Previously I found the basshorn a bit boomy, but today I asked them to increase the volume and it is just the lack of lower midbass from the Avantgarde Trio. The sound from the basshorn is crisper than a regular subwoofer, but not much detail is left after it has been folded several meters. So it behaves just like a regular subwoofer, with not much usable sound above 80-100Hz, just slightly more snappier och crisper, but maybe also muddled from having such a long folded horn. Someone can probably explain why, better than me.
The Trio itself is fine, I just prefer my version which can produce a full midbass without the help of a subwoofer/basshorn, crossed a little too high.

This is a cafe? where is it?