La Scala Bass Reflex Mod

[moray james]

a good project to remember Dennis by.

[Full Range]

On 9/5/2018 at 10:08 PM, BrianJacobs said:

are you guys screwing the bass bin to the La Scalas, or just using the 123 pound weight of the La Scala to seal the boxes? 

 

Just a high density rubber compound seal is used - Hope these photos help 

 





[OO1]

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[BrianJacobs]

played with the reflex bin in multiple configurations, no foam, some foam, lots of foam. while I did find the freq. to be a bit lower it seemed to loose its snap. I am convinced PWK is a much better audio engineer than I am and back to standard box (with upgraded components) and if I want more bass I will turn my sub on. 

[OO1]

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[Marvel]

That only worked when he had them in corners.

[richieb]

23 hours ago, Randyh said:

the only way to get more bass from a Scala is relatively very simple - remove the dog house and seal off the dog house opening - then add a full 1 inch motorboard - like all regular bass reflex speakers , then you will have real bass -   the scala design is just not made for bass , in comparison to a k-Horn , there is simply no volume - or again , make a bigger doghouse  , and more volume , and you will have more bass -

 

=== - and you have nothing remotely similar to a LaScala. —“make a bigger doghouse, and more volume and you will have more bass”. And no longer have a LaScala —. Getcha some Cornwall’s- whala’ - more bass

[OO1]

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[OO1]

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[OO1]

bump

[ClaudeJ1]

10 hours ago, Marvel said:

That only worked when he had them in corners.

Yes, while killing the 200-400 Hz. response. Get a Jubilee.

[ClaudeJ1]

10 hours ago, Randyh said:

 

I agree , 100% ,  I own CW and Scala speakers , when I bought my industrial Scalas , I wondered why the speaker was anemic as far as bass , now the brochure did say the bass was good , but it didnt say , that it was a tiny bass , and a 43 has even less bass than a k33 --

Get a sub, preferably a horn sub.

[Marvel]

Below approx. 125Hz., a La Scala acts like a direct radiator, due to the smallish horn in the bass cabinet. That was and is the whole point of making the doghouse larger (either by adding the extension underneath or by opening the top and enclosing the back) and porting it. If the port tubes are over 7 inches the bass will get a bit sloppy. The other thing on La Scalas, which I almost always recommend, it to move the mids down abut 3db. This will allow you to turn up the gain (to get the mids back), while then bringing up the bass.

 

Bruce

[Marvel]

Tom Brennan always said LaScalas were like having a buzz saw hit between the eyes. 😉

[ClaudeJ1]

6 minutes ago, Marvel said:

Below approx. 125Hz., a La Scala acts like a direct radiator, due to the smallish horn in the bass cabinet. That was and is the whole point of making the doghouse larger (either by adding the extension underneath or by opening the top and enclosing the back) and porting it. If the port tubes are over 7 inches the bass will get a bit sloppy. The other thing on La Scalas, which I almost always recommend, it to move the mids down abut 3db. This will allow you to turn up the gain (to get the mids back), while then bringing up the bass.

 

Bruce

DJK's (RIP) mod with the 7" tubes appears to be the best way to squeeze the most performance from a LaScala, along with the active filter/boost. Plus it raises up the tweeter. That being said, I would still prefer a THT or F20 sub if there's room, since, unlike a tapped horn, you can use them from 20-100 Hz. (LaScala has a 104 Hz. cutoff as a horn). Even with the DJK mod, the LaScala is still smaller and better than a Voice of the Theater, which also adds bass reflex to a short horn.

 

[Marvel]

It has been a long road for me to get this beater pair of LS back into use. All I got for $100 was the cabinets, so I had to accumulate parts over time. I decided to front mount the K-400, which causes another problem in that they don't fit flush. I will need to use caulk to seal them to the top section. I still have to get the backs enclosed as well. I will first use them without the bass ported (I have the opened doghouse closed of at the moment). Once I get that done I will try to run some sweeps and then finish off the porting and run them again for comparison. I thought I would have them done last summer, and now this one has pretty mush slipped away.

 

Life gets in the way, and in the end I won't have them. I'm NOT shipping them to the Philippines!

[pioneerhip]

On 8/22/2009 at 11:22 PM, sootshe said:

So..... sealed aroung the perimeter of the dog house opening....& used off cuts to double seal any potential gaps.

Then put another seal around the external sides. I cut all pieces slightly oversize so they would butt up tightly.

Do you have the measurements for this piece?

[Full Range]

On 11/28/2018 at 7:49 AM, pioneerhip said:

Do you have the measurements for this piece?

 

 

I see you are a new member and welcome to the Klipsch community 

This information was posted on the previous page 

 

But I will repost it again just for you 😎

However and please NOTE - the outside measurements of the bass extension need to coincide with the bass / dog box of your speakers

 

 I have measured the Bass extension cabinet of my La Scalas that were built by the Original Poster - @sootshe

 

Edit 

The bass drivers in this build are Crites 

Some people prefer the tube length to be 7” to 7.5” when using the original klipsch bass drivers 

 

 

[pioneerhip]

Thanks for the reply and welcome!

 

I am going to have someone else build them for me and was hoping to not have to flip the La Scala upside down to get the measurements for the entrance to the dog box. Thanks for the photo attached it is a big help. I guess I'll flip the ol La Scalas upside down soon and take the measurements 😃 Its hard to take them out of rotation!

[DizRotus]

Aesthetically, the outside dimensions of the box should coincide with those of the La Scala. It is not necessary to turn your La Scalas upside down to get those measurements.  The dimensions of the openings need not match exactly.  It is important that the La Scalas and the boxes be sealed together and that the overlapping openings have a surface as large as possible; substantially greater than the combined areas of the port openings.  For example,  the upper board with the cut out in the exploded drawing above could be eliminated completely if the seal between the La Scala and the box is achieved.  Having that board in place provides more surface are to effect a seal.  Better that the opening to the box be larger than the woofe access hole, than smaller. In any case,  the seal between the La Scala and the box can be achieved using gravity and weather stripping.