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Discussion Starter #21 (Edited)
Matt sent me a good question via P.M.

He asked if other drivers could be dropped into the horn to make it work, as in less expensive drivers.

The answer is yes, there are a few that will give you most of the performance.

Lab 12 comparison.png

The LAB12 will get you pretty close. And it is quite a bit less money. So if it the cost of the driver that is holding you back this one will get you most of the bang for the buck. It is about 2 to 3 db different in a few areas. So no real big deal.

For those that want the ultimate, there is still the pro drivers.

As for actual excursion numbers there is a discrepancy between the X-max figures given for the TRIO12 and the actual performance of the TRIO12.

About a year ago Bob was questioning if he should build another run of the TRO12. I did some very exhaustive tests on the driver. It turned out that the mechanical excursion available was only 15mm. This was tested over a dozen times because I kept thinking I was doing something wrong. It was on a driver with many hours of play time, so it was broken in. In fact I developed an almost fool proof method of testing the mechanical excursion that use to this day. It was decided to delete this driver from the line.

So that explains why this driver is no longer available. It was not up to CSS standards of quality.
 

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Thanks for posting that comparison Mark. If the sims are to be believed, something tells me that my house will be hitting its drywall cracking limits before I'd max out even the Lab12.
 

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Okay... I'm trying to plan this out in detail now. Turns out I don't quite have the 92" of height to stand it upright in the basement :( so looks like I'll be disguising it as a rather large bulkhead instead...still with the mouth ducted in through the floor.

What are the dimensions of the mouth when it's placed on the long narrow side of the box?

Thanks
Matt
 

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Discussion Starter #24
Mouth dimensions stay the same in any point on the box faces.

The key is the same area.
 

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Discussion Starter #25
Ok a couple of points.

Anybody building or getting ready to build.

Post all questions, criticisms etc here.

My skin is not thin, and I don't bite. Making this better and smoother of a build is the aim.

Second.

What can we call this thing?

I know that the thread is about as lame a name as I could come up with.

Ultimate subwoofer comes to mind.

Can a Moderator make the change?

Calling Mr. P Mr. Mike P.
 

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Discussion Starter #30
"Kravchenko Krusher"
ALright! :scratch:

Now I'm a fairly big dude.

But not that big!:yikes:

A name like that belongs in wrestling.

But maybe .........
 

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A couple thoughts I had:
"Kravchenko Thunder Horn"
or
"Ultimate Front-End Loader Horn" since Mark used a tractor to lift the prototype.
 

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I personally like "The Kravchenko." Strong name already. :D
 

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Discussion Starter #34
So not even a peep from all the builders. Either everything has gone swimmingly or down the drain.

Only time will tell.
 

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Discussion Starter #36
With all that polyurethane adhesive floating around they may have glued their fingers together!
 

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I got my plywood and PL purchased and made the long cuts with my father over Christmas break. He's got a great wood shop and I would have loved to get more done while I was there but couldn't get more than a couple hours away from the rest of my family.

We're back home now and I'll start my build thread this weekend.
 

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Discussion Starter #38
At least you put first things first. Looking forward to seeing your progress.
 

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Mark

Is there a measurable difference in the output or sound quality of
the original end 'exhaust' build versus the modified side 'exhaust'
build? ...Why or why not? -Thanks.
 

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Discussion Starter #40
Is there a measurable difference in the output or sound quality of
the original end 'exhaust' build versus the modified side 'exhaust'
build? ...Why or why not? -Thanks.
Sure ask the easy questions. :scratch:


Well the straight and simple answer is there is no difference. No measurable or audible difference.

The question that follows is why?

Basically in a horn air is being pumped and it is constantly under pressure that is higher than atmospheric pressure until it exits the horn. Compressed air behaves more like a fluid than like air at normal atmospheric pressure. So take this one level further to understand why it makes no difference.

Take an imaginary water tank. Say a 5 gallon bucket, and drill a one inch hole on the bottom. The water will drain out right?

Drill the same size hole on the side close to bottom, and the water will still drain out of the bucket. At the same speed too, as the exit is exactly the same size.

Our horn has the same criteria. Keep the exit area the same on a side or end exhaust and it will "drain" at the same speed.

But says you, what about the sound?

Ok lets get into some waves.

Sound is composed of a multitude of pressure fluctuations that have amplitude ( louder or less loud ) and physical dimension. Take 16 hertz as an example. A half wavelength of 16 hertz is approximately 32 feet. The full wavelength is 64 feet. This is more or less the designed low end of this horn. So pop up and octave or three and see what the wavelength of sound is.

One octave is a doubling or halving of frequency, so here are some numbers:

16 - 32 - 64 - 128

The dashes represent an octave spread. The numbers are the frequency in hertz.

Corresponding half wavelengths are:

32 - 16 - 8 - 4 ( sorry this is in feet )

Full wavelengths are double that so:

64 - 32 - 16 - 8 ( feet )

No one is going to use this horn up to 128 hertz. But say you did. The physical wavelength of 128 hertz, even at the length where a horn can manipulate it's sound with effect ( a quarter of the wavelength ) is still 2 feet. So as long as these conditions are met there will be absolutely no change in output.

The exit area is the same either on the side or the end of the horn. And there is less than two feet difference in the location of the exit.

Keep in mind a horn works on path length so I'm still promoting an exit close to the very end of the horn.

Hope this long winded piece will answer the questions.
 
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