How far from a Klipsch type horn can I possibly get?

[Marvel]

In actuality, they should take up the same amount of room my DBBs are taking now. I currently have the DBBs laying on their side since adding the Oris horns on top made them too tall to keep the DBBs upright. The mouth of the wave guide is about 48" and the whole thing is about 26" deep minus drivers.

Thanks for the pic of the back and giving the dimensions. They take up less room than I thought.

They look cool! If they sound good, then what's not to like?

In the end, we want what we like to listen to, yes?

I appreciate all the work you put into these searches, and even more so like the fact that Klipsch will let you put all of this on here.

Bruce

[mikebse2a3]

Interesting design Rudy. The Orelo plots are showing you the advantages of polar control and it's effects on efficiency and smoother response vs the dbb design at the listening position. The polar control is also in evidence in the front vs back plots of the Orelo.

miketn

[Rudy81]

Bruce,

I'm putting this experiment on here since I know quite a few guys like to tinker with this stuff. True, I appreciate Klipsch allowing us to talk about other designs etc.

I agree that what is best is what you like to listen to.

[Rudy81]

Interesting design Rudy. The Orelo plots are showing you the advantages of polar control and it's effects on efficiency and smoother response vs the dbb design at the listening position. The polar control is also in evidence in the front vs back plots of the Orelo. miketn

So you attribute the improvement in response and efficiency to polar control. Interesting. I'm still not clear on the whole polar control issue, but I do have some basic understanding of the concept. I just can't believe such a simple design, which BTW is Bert Doppenberg's (he has been nice enough to assist with my build, even though he sells the Orello), would work so well.

What are the drawbacks? I realize the DBB can go lower in response, near 40Hz, which this thing cannot do. I don't understand why this type of setup has not taken off more. Particularly in the days of good subwoofers etc.

[Guest David H]

I still can't get over the fact that this thing actually works with no enclosure! Just crazy.

This is a sweet looking design. Have you considered installing a cap on top of the horn, this might help with the 300hz drop you are seeing indoors.

I suspect from looking at your graphs you have some cancelation. The floor and wings provide plenty of separation however I suspect the open top is allowing phase cancellation. Try placing a board across the top and see if that helps.

You may want to look at H frame open baffle designs.

Very cool project.

Dave

[Rudy81]

Dave,

I have considered adding a top to enclose the wings and see what happens. One issue is that the Oris horn hangs down into the space right now. On the plus side, I don't need to go past 200Hz with the woofers. So, the need to go above 200Hz is not a big deal to me. I just noticed that the response dropped in room vs. the outdoor measurement.

It will also be simple to add some side panels to give it an H type setup. Lot's of stuff to try and overall very simple in implementation.

BTW, I found some screen mounting hardware that makes a perfect clip for mounting the woofers.

[Guest David H]

I have considered adding a top to enclose the wings and see what happens. One issue is that the Oris horn hangs down into the space right now. On the plus side, I don't need to go past 200Hz with the woofers. So, the need to go above 200Hz is not a big deal to me. I just noticed that the response dropped in room vs. the outdoor measurement.

I would certainly give it a shot, this will mostly impact low frequencies, however I suspect it would straighten out the null at 300hz.

Did you lose a bit of spl running the woofers OB?

Dave

[Rudy81]

I would certainly give it a shot, this will mostly impact low frequencies, however I suspect it would straighten out the null at 300hz.

Did you lose a bit of spl running the woofers OB?

Dave

Dave,

I plan on trying out your theory when I get things set up in the media room in a few weeks. In particular my center channel is crossed at 800Hz, so I would rather not lose much above 200Hz.

I am still in awe of what the OB can do. NO, I did not lose any SPL compared to the DBBs. In fact, when I tested a single OB in my room to see the room interaction I noticed it was 'louder' when compared to the opposite DBB. I figured out the OB is more efficient than the DBB and plays louder with the same setup and same drivers. I get a Qts of .55 with both Kapplite LFs in parallel, on the baffle.

The other thing which jumped out at me was the relative lack of room mode interaction with the OB vs. the DBB. The plot below is totally raw and you can see very little room interaction in the LF. My DBB or Khorn plots were full of room modes unles I played around with the gating. Just weird...I never would have believed the OB can compete with an enclosure. Of course, the lower frequencies do suffer in the OB vs. the DBB. I can run the DBB down to 40Hz outside no problem. The OB started rolling off below 100Hz. That can be remedied with some different drivers and EQ. In order to get the 80-200Hz I need I will need to EQ just a little. Based on the in room response, I plan on attenuating the range between 100-250Hz, rather than boosting from 80Hz on up. I'm not sure if that is the suggested technique, but I know the drivers can handle plenty of power and I have plenty of it so matching the Oris Tang Band driver should not be a problem.

[Guest David H]

I am still in awe of what the OB can do. NO, I did not lose any SPL compared to the DBBs. In fact, when I tested a single OB in my room to see the room interaction I noticed it was 'louder' when compared to the opposite DBB. I figured out the OB is more efficient than the DBB and plays louder with the same setup and same drivers. I get a Qts of .55 with both Kapplite LFs in parallel, on the baffle.

A Qts of .55 is usable for OB, and your graphs look good. Seems like you are on to something to me.

I know the feeling, I am constantly in awe about the open baffle sound.

Dave

[mikebse2a3]

"So you attribute the improvement in response and efficiency to polar control. Interesting. I'm still not clear on the whole polar control issue, but I do have some basic understanding of the concept. I just can't believe such a simple design, which BTW is Bert Doppenberg's (he has been nice enough to assist with my build, even though he sells the Orello), would work so well."

Hey Rudy....certain frequency wavelengths that fall under control of the "waveguide" (which with the wings and floor are providing 3 finite boundries and is acting like a horn to some degree and thus changing the air impedance load on the drivers at those frequencies) will show an increase in efficiency on axis and the wings being angled will also add some directivity control at those frequencies. Note: If you add a top as mentioned then a basic rectangular horn is formed.

You can see this evident in the front versus back spl graph to some degree.

"What are the drawbacks? I realize the DBB can go lower in response, near 40Hz, which this thing cannot do. I don't understand why this type of setup has not taken off more. Particularly in the days of good subwoofers etc."

Well they can be viewed as drawbacks or attributes depending on a persons goals.

You basically have a system that is acting as a dipole open baffle design combined with a waveguide(ie:horn) at certain frequencies. There will be cancelations and nulls to the sides at very low frequencies and as the frequency wavelengths approach the baffle/waveguide(horn) dimensions you will see an increase in efficiency and on axis spl will rise as the energy is focused in a narrower angle in the forward direction (note: the rear wave will not see this focusing waveguide/horn loading effect.

miketn

[mikebse2a3]

The other thing which jumped out at me was the relative lack of room mode interaction with the OB vs. the DBB. The plot below is totally raw and you can see very little room interaction in the LF. My DBB or Khorn plots were full of room modes unles I played around with the gating. Just weird...I never would have believed the OB can compete with an enclosure. Of course, the lower frequencies do suffer in the OB vs. the DBB. I can run the DBB down to 40Hz outside no problem. The OB started rolling off below 100Hz.

The dipole side cancellations will definitly change the room mode interaction and for better or worse it will be room dependent as any system design will be.

Even if the DBB vs the OB measured or was eq'd identical on axis they wouldn't sound the same because of the polar differences of the two very different systems. This is why a simple basic on axis measurement can never totally describe the perceived sound of a loudspeaker in a room by itself.

Now if you could here two systems with very different polar responses but identical on axis measured responses in an anechoic chamber (or outdoors to a limited degree) then they would be perceived as very similar because the polar spl variations with room interaction never comes into play to be perceived by the listener.

miketn

[Rudy81]

Mike,

You have forgotten more about acoustic theory than I will ever know. However, learning all this stuff is really an enjoyable experience.

The true test of this experiment will be when I set everything up and really just listen to it. It is now a few weeks off, but I look forward to the experience.

I am very excited at the possibilities of this project within the limited scope of my requirements.

[DrWho]

How did you decide on the shape of the flare?

[Rudy81]

How did you decide on the shape of the flare?

I got the basic plans from Bert and he has assisted me with the basic build. The flare is just a simple curve, roughly 4' in radius.

[Rudy81]

After several weeks of work, I finally got to hook these things up. Based on initial impressions and prior to doing any tweaking, I think these are going to be keepers. Time will tell. I just couldn't resist listening to them after all that work. Thought I'd share some pictures before getting into the in-room response testing.

[Rudy81]

I still need to add some speaker spikes to raise them off the floor. According to Bert Doppenberg, lifting them will improve things just a bit.

Three of these things fill up a big room. I'm so glad this room is not subject to WAF....

[Rudy81]

Behind the open baffle...I still can't get over how good these sound and how simple the baffle is to build...the 'wings' are something else entirely.

[Guest David H]

Excellent......

Dave

[The Dude]

That is some heavy speaker wire, those are looking great.

[Rudy81]

That is some heavy speaker wire, those are looking great.

Thanks, they look ok, but they would not win any quality woodworking contests. I might consider these prototypes since it was my first shot at creating curved surfaces like that. At some future time, if they work out, I might look into making some nicer ones with a thinner profile at the throat and with a material that will take the lacquer better.

They definitely have a cool factor to them. I hope to have time tomorrow to take some frequency plots. I will also need to check the two SPUDs and make sure nothing major changed when I moved them. Since the center channel now blocks the middle of the screen area near the floor I had to move the SPUDs so that the horn openings are near the edges of the screen vs. the center. It will also be interesting to see what the center LF section can do...I need it to go up to 800Hz or so.

I sure am glad the room in large enough to handle those things. They are just over 52" wide at the mouth of the wings.