is this a form of rear load horn scoop?

Not too different to this thing i have drawn a while back...

Only your driver fires into the mouth...

But I have a sneaking suspicion that the same tline/horn theory applies to mini scoops. Unless the mini scoops are actually mass loaded [img]smileys/smiley3.gif[/img] (think of a horn with a plate across it so only a small section of the mouth is visible, this can be modeled in hornresp with an extra section with a very small length...)

Quick thought exercise for you scoopers...

Take an ordinary scoop and another one and mentally stack them not mouths together but drivers together. Modify it mentally so that the very tall double scoop now has the driver firing onto two horns, each can either be loaded of either end of the now enlargened rear baffle, or they can lead off a single hole in the middle of the rear baffle. What do you have now? it resembles a tall slim W-Bin with a driver moved up to the flat bit between the mouths. Now think of each mouth as a driver, bass drivers, and replace the direct radiator with a mid.


what do these look like?

Deadbeat wrote: Mykey, those Lowthers... I looked at the price list and...well....[img]smileys/smiley9.gif[/img]

On these types of t-line/horn speakers:
(most "horns", including the Frugel-Horn are actually hybrid TL/horns. Below a given frequency the mouth is not large enough to damp the pipe resonances giving undamped TL action. Above this frequency the mouth becomes large enough to provide the horn damping and you transition to a horn loading.)

copied from frugel-horn.com

They sent me the trade X works prices and i thought they were the retail prices ....still! when your the best,I suppose you can demand it

[img]smileys/smiley3.gif[/img]

But whether they're the best is debatable...

Most people use cheapy Fostexes (which are still very good drivers, especially with modification, some on par with Lowther)...

But once you get into the higher ranges, like the 108ES-R and all those limited ones and the Japan-only specials, Lowther's look like midranges. Not like I can afford any...[img]smileys/smiley36.gif[/img]...I just got to try some out, THEN see the price lists [img]smileys/smiley3.gif[/img]

And when we get into stuff like the French manufacturers like PHY-HP and Fertin, the rices become very strange indeed.

I think the fullrange driver blh band can help a lot with modern scoop design. They concentrate on a good clean midrange, and squeeze as much bass as possible out of a tiny speaker without overexcursion, which is a challenge as one of the popular drivers has an xmax of 0.35mm (well, others have xmxes of 9mm+).

Some more thoughts. Most of you will know this, but it's nice to link it all up.

The first applies to any design.
You get standing waves in any enclosure with parallel walls. This occurs at frequencies determined by this:

f = 344/x/2

f is the frequency in which the first resonance occurs
x is the length between the walls in metres
2 gives the half wavelength.

So resonances appear in the half wavelength frequency. They also appear in upper harmonics, this is given by multiplying the number you just found by 1, 3, 5, 7, and onwards.

What does this have to do with making a scoop play mid?
Simple. If you look at nearly all the fullrange designs, you will see that there are parallel surfaces, yes, but the distance between them is minimised (hence the flat looking designs), so the resonances will be much much higher. The other option of course is non-parallel walls as much as possible.

Part 2 will deal with the baffle, and how it is dealt with.

In the following episodes, we will touch upon more design features. Including - the use of BB, BVRs and more! Stay tuned.

Good stuff, I will stay tuned!

Baffles debaffled. This is a BASS MATTER, so listen up!

Some resources needed for my next installment. You don't have to read them all, but I would suggest at least one out of the articles given:

frugel-horn design sheet (don't you wish people released designs like this???)
homepage.mac.com/tlinespeakers/FH/downlo...n-v1-maps-130307.pdf
See pages 1, 16 and 17 for info on the 'Suprabaffle'.

The Edge, a free Baffle Step simulation program (it's very very easy to use):
www.tolvan.com/edge/
If you want to see it happening, have a play with this and plug in different shapes and sizes.

tline's article on Baffle Step
www.t-linespeakers.org/tech/bafflestep/index.html

Rod Elliot on Baffle Step
sound.westhost.com/bafflestep.htm

John Murphy's which inspired Elliot's, only included for completeness (has extra graphs).
trueaudio.com/st_diff1.htm

Some pages from Olson's Acoustic Engineering, buy it, it's indispensible.
The shape of the graph is what is interesting, not the frequencies really.

Page 23 is the only one that shows up [img]smileys/smiley11.gif[/img] so here's links to the other important ones:
www.diyaudio.com/forums/attachment.php?s...785&stamp=1042615260
www.diyaudio.com/forums/attachment.php?s...974&stamp=1158429306

Edited by: Deadbeat

For the nonbelievers-

look at page 23 and these.

Mykey's UFOs. Spheres, the best possible one (from a BSC point of view).


Truncated parallelepiped
Note the curved mouth and reflector on the back, I may cover these yet. It's in the plans that I linked.

I like the look of those rear refector panels, they would make the horn mouth seem massive.