La Scala Horn

[Duke Spinner]

has anyone got some plans for a " Dean " ..???

[D-MAN]

Duke, here ya go.

DM

[D-MAN]

Here's the Classic, as well...

DM

[pauln]

OK, instead of cutting the corner walls to make a recess for the LS, what about cutting some slots in the back to allow the horn to split a second time on each side and use the walls and the sides of the LS to extend the horn - would have to build a couple of add on panels (in red) to do so... what about that?

[Daddy Dee]

The "Dean" looks interesting. Is that a cobraflex mounted in the horn?

[Guest " "]

OK, instead of cutting the corner walls to make a recess for the LS, what about cutting some slots in the back to allow the horn to split a second time on each side and use the walls and the sides of the LS to extend the horn - would have to build a couple of add on panels (in red) to do so... what about that?

due to the nature of the throat design, rather than cutting slots in the main cab, you are better off creating an elevated base for the lascalas with the back open, dog house access panel removed, and a panel inserted in the elevated base on a slight angle (simular to the pitched baffle and open back design used in the aristocrat).

.

[D-MAN]

Daddy-Dee, that is indeed a Cobraflex.

Pauln, THERE YOU GO - THINKING OUTSIDE THE BOX AGAIN! Good job!

DM

[Bill Cain]

due to the nature of the throat design, rather than cutting slots in the main cab, you are better off creating an elevated base for the lascalas with the back open, dog house access panel removed, and a panel inserted in the elevated base on a slight angle (simular to the pitched baffle and open back design used in the aristocrat).

What if the La Scala bass bin was aimed INTO a corner, so that the effecive horn size was the same at the beginning of the wall-floor horn as the La Scala horn?

The floor and walls would effectively be three sides of a horn. A triangular fourth "wall" could then be lain on top of the bass bin, creating the fourth horn wall.

All that would then be needed is an appropriate wedge-shaped insert, for the corner, to transition the La Scala horn effectively to the wall horn.

Stack two bins to double the effective horn size and halve the cutoff frequency.

Any flaws in this approach? []

[ajsons]

This mod doesn't take a lot of work, if you have a split La Scala and completely reversible. Have the La Scala facing down to the floor, add four legs about a foot long, and you got a floor horn. Then put in the room corner. Sort of a mini-Monolith horn (Edgar's).

In a corner, the horn will exhaust through the (new) front and one side.

The legs can be a totally separate assembly, with horizontal crossmembers, and the enclosure just sitting on it.

Armando

[ajsons]

If you have a wooden floor that absorbs a lot of bass energy like Edgar's, or if you want to place the enclosure against a wall, not in a corner, add a pyramidal reflector. The horn exhausts to the front and the two sides.

[D-MAN]

Armando, that is so cool. And your drawings! Wow!

Just a reminder to all that you're not going to gain any more low frequency reponse, the flare rate(s) remains the same, and it will raise the overall Fc slightly higher (the LS uses 2 separate flare rates and the one you are expanding is the higher of the two (120Hz!).

You would have to change the flare rate on the "addition" to gain a lower frequency response, however, even an additional "addition" of doubling the size of the exit in 18" of travel from the "original" will lower it down to approx. 50Hz or so for the overall Fc of the combined flare rates. Unfortunately, changing the flare to gain a lower frequency cutoff will make the horn "peaky" because the mouth size is still too small for a lower Fc. That's the rub, kids.

However, maintaining the same rate will be more efficient and have a smoother response due to a larger mouth size, especially for 1/2 space placements. A corner could be exploited a bit...

Dana

[ajsons]

Thanks, Dana.

Like at my work, it's always nice to have somebody with more design experience to check your drawings. I appreciate your inputs very much. Someday, I'll earn that horn designer badge.

Armando

[Guest " "]

If you have a wooden floor that absorbs a lot of bass energy like Edgar's, or if you want to place the enclosure against a wall, not in a corner, add a pyramidal reflector. The horn exhausts to the front and the two sides.

couldn't you do this by removing the dog house access panel and make a base per your diagram. Alloing the lascala to operate normally from the front of the driver, and having the rear of the driver project to the floor.

[ajsons]

couldn't you do this by removing the dog house access panel and make a base per your diagram. Alloing the lascala to operate normally from the front of the driver, and having the rear of the driver project to the floor.

The horn will not function "normally" from the front 'coz now you don't have a compression chamber.

[Bill Cain]

Just a reminder to all that you're not going to gain any more low frequency reponse, the flare rate(s) remains the same, and it will raise the overall Fc slightly higher (the LS uses 2 separate flare rates and the one you are expanding is the higher of the two (120Hz!).

You would have to change the flare rate on the "addition" to gain a lower frequency response, however, even an additional "addition" of doubling the size of the exit in 18" of travel from the "original" will lower it down to approx. 50Hz or so for the overall Fc of the combined flare rates. Unfortunately, changing the flare to gain a lower frequency cutoff will make the horn "peaky" because the mouth size is still too small for a lower Fc. That's the rub, kids.

However, maintaining the same rate will be more efficient and have a smoother response due to a larger mouth size, especially for 1/2 space placements. A corner could be exploited a bit...

Dana

Let me try this again........

What if the La Scala bass bin was aimed INTO a corner, so that the effecive horn size was the same at the beginning of the wall-floor horn as the La Scala horn?

Sorry, I don't have a diagram. []

The floor and walls would effectively become three sides of a horn. A triangular fourth "wall" could then be lain on top of the bass bin, parallel to the floor, creating the fourth horn wall.

All that would then be needed is an appropriately shaped reflector, for the corner, to transition the La Scala horn effectively to the wall / cabinet exterior horn.

Would stacking two bins double the effective horn size and halve (or significantly lower) the cutoff frequency?

Any flaws in this approach? []

[djk]

Stacking a pair of LaScala helps quite a bit, four of them per side pack a good punch! Deep bass? Not really.

Its all about taper rate and mouth area. As D-MAN said: you can increase the mouth area various ways, but your taper rate just isn't there.

Best pair of non-vented LaScala I heard were flush mounted in a pair of block-wall corners at the ceiling, with 6dB boost at 32hz, and a similar cut in the 128hz band, a small ~2dB dip around 1Khz, and about 3dB boost at 16Khz.

[jorjen]

Bill,

Interesting concept, don't know if your exact idea has come up before. Just for the heck of it, later today or tomorrow, I will toss together wedged reflectors/splitters for the corners of my room and turn my La Scalas into the corners. Right now I have the wood Tractrix horns I built and JBL 2404H's just sitting on top of the cabinets. All I have to do is turn them around, piece of cake. I will listen and play with placement(distances into corner, from adjacent walls, etc.) a bit before reporting back. I will take some pictures as well.

Any thoughts on the distance from the adjacent walls to the front of the cabinets(shoved into the corner at 45) outer edges(horn mouth)one would desire to continue the mouth/flare in a somewhat close to ideal manner? Once this is determined, I will construct the reflector to the needed size to come close to the front(back)of the cabinet.

Oh, one more thought. I assume we would also want to seal off the top of the bass horn with a wedge running from the front bottom edge of the top section into the corner, like the Khorn right? So, the reflector/splitter would be the height from the floor to the top of the bass bin and the sealing wedge would go from the front of the La Scala and rest on top of the reflector/splitter in the corner. Otherwise we will have waves escaping out the top vertically. Am I making sense?

[Guest " "]

couldn't you do this by removing the dog house access panel and make a base per your diagram.  Alloing the lascala to operate normally from the front of the driver, and having the rear of the driver project to the floor.

The horn will not function "normally" from the front 'coz now you don't have a compression chamber.

My understanding is that the compression chamber in a horn loaded woofer is actually the area in front of the woofer. see attached diagram and look at area vf indentifed as a compression chamber.

While I was in europe from 86 to 89, I did a lot of work recovering and re-directing sound waves from the "enclosed" area of speaker cabinets. In this particular senerio, a base bin with an open side, fitted with a horizontal baffle 3/4's the lengths of the base bin, angled as the horrizontal baffle used in the electrovoice aristrocrat, would recover some of the waves while not canceling out the waves from the front.

The idea of turning a lascala around and directing the waves into a corner or floor, would result in loss of some of the waves in the mid-bass area.

[WMcD]

Speakerfritz,

May I inquire from where the diagram and equation came.

Thanks,

Gil

[Guest " "]

Speakerfritz,

May I inquire from where the diagram and equation came.

Thanks,

Gil

The original source is a set of klpisch papers that are in paper circulation as part of a dealers kit called klipsch notes.

Someone on the fourm uploaded the particular image as part of another discussion.

If you want the whole article, let me know, and I'll check my dealers kit to see how many pages it is.