Who did it, are you happy with it, would you do it again, etc. ... the Lascala Bass bin addition

[Wrinkles]

Hello Fellow Audiophiles,

I have been reading with great interest your Forum comments about the Lascala Bass bin mod. Although, not too much has been mentioned in a while. So, I wanted to know if you are still happy with it, still have it installed, what kind of bass response did you get from it, any required crossover mods required, etc. I do NOT want to enclose the mid horn and tweeter area, even though I am not using them right now. For right now, I want this to be completely reversable.

I want to add to the low end frequency range of the LaScalas. I do not want to add seperate subs and I really do not want to modify the crossover, if possible (I have the AL-3 crossovers).

I also need the dimensions of it and what plywood/partical board thickness you used. I have the LaScala base plate length and width only.

Thanks for your opinions, insights and information.

Wrinkles

I just reread my post. Although I sound demanding with my "wants" I do not mean to come across that way. I just am very interested in this mod.

[jacksonbart]

Not going to do it again, but I am happy.

[Groomlakearea51]

Considering it, but happy the way they are now in case I change my mind before doing it...

[DrWho]

What kind of processing do you have available? The reason I ask is

because djk (the guy that came up with the mod) is using a peaking 2nd

order highpass for this mod. It rolls off the lows below the tuning

frequency, but it also boosts the output at the tuning frequency. Below the tuning point the cone becomes unloaded and the excursion becomes very large, which the high pass eliminates. But at the tuning frequency, the cone excursion is a minimum so as long as you're not thermally limited, you can practically boost it as much as you want - in this case boosting to a flat response.

Without the EQ, there are minimal gains to be realized...and more distortion if you don't limit low frequency content.

[jacksonbart]

Ok, I might have done it once, but that does not count, if you tell anyone I will deny it, I am still happy.

[mas]

I realize that everyone will get upset at this suggestion, but if you want to truly augment the LaScala's bass low end response, instead of playing around and adding only a few hertz to the response with a reflex mod, simply adding a quality subwoofer would make a much greater contribution, extending the LF range much deeper with much greater flexibility in terms of sensitivity for both music and home theater enjoyment.

[Coytee]

I realize that everyone will get upset at this suggestion

I am now officially upset...

[colterphoto1]

[in best Fonzie voice]

CORRECTUMENDO

[colterphoto1]

[in best Fonzie voice]

CORRECTUMENDO

[Rotorhead09]

Yes, I would... I just don't have the time now!!

S. Lee

[seti]

I have never seen this mod. How do they sound? They look very cool!

[Marvel]

I realize that everyone will get upset at this suggestion, but if you want to truly augment the LaScala's bass low end response, instead of playing around and adding only a few hertz to the response with a reflex mod, simply adding a quality subwoofer would make a much greater contribution, extending the LF range much deeper with much greater flexibility in terms of sensitivity for both music and home theater enjoyment.

I would say that flat to 30Hz is rather respectable, considering the low cost of the mod. Plus, the eq mod isn't required.

Bruce

[Marvel]

Rotorhead, you have been living with those for some time now. Do you still like them, and can you give a comparison to the stock LaScala?

Bruce

[DrWho]

I would say that flat to 30Hz is rather respectable, considering the low cost of the mod. Plus, the eq mod isn't required.

Flat to 30Hz? I think our definitions of flat differ by quite a bit. Here is a graphical representation of the measurements you so often refer to in the other threads:

[DrWho]

One of the problems with this measurement though is that it was taken

in a room and only has a very poor resolution and none of the details

surrounding the measurementn are provided. The peak at 65Hz in

every measurement is very clearly a standing wave in the room, masking

the fact that

the horn is typically 6dB down from 50 to 100Hz. We do see the typical

6dB gain at the tuning frequency and the 40Hz dip is again room

related. It also looks like there is a standing wave right around 32Hz

too (notice how the different tuning points have peaks at the same

frequency). Also, the natural roll off of the original cabinet

shouldn't have a peak at 30Hz either. The higher tuning frequency is

getting masked by the room induced dip.

Nevertheless, you can clearly see that you need at least 10dB of

attenuation down low. I think Dennis recommends around 6dB because

there is a peak around 150Hz that is about 4dB higher than the rest of

the bass bin's passband. With the EQ, you can expect cornwall-like performance except you don't have the 5dB rise at 80Hz.

Without

the EQ, you're talking marginal shifts in timbre. With the EQ, you

definitely have more bandwidth, but at what distortion increases? djk

recommends the K-43 instead of the K-33 in this application because it

has both better efficiency and more power handling (making the

distortion increases less dramatic).

It is definitely a very cool inexpensive mod, but it would be naive to

believe that it yields the best possible performance for the bottom 2 octaves.

[DizRotus]

The thread linked below contains links to most of the threads relating to the djk ported La Scala mod. It also details the process and results as applied to a pair of survivors of long-term duty in an <?xml:namespace prefix = st1 ns = "urn:schemas-microsoft-com:office:smarttags" />Ohio bar. Their current location is far from ideal, but after listening to them in their current environment and under more favorable conditions, I would not own La Scalas without the mod. Even when done though the top of the dog house with the top enclosed, the mod is completely reversible, but I am not aware of anyone who has gone back to stock. <?xml:namespace prefix = o ns = "urn:schemas-microsoft-com:office:office" />

Ported La Scalas

http://forums.klipsch.com/forums/thread/761099.aspx

[Marvel]

One of the problems with this measurement though is that it was taken
in a room and only has a very poor resolution and none of the details
surrounding the measurementn are provided. The peak at 65Hz in
every measurement is very clearly a standing wave in the room, masking
the fact that
the horn is typically 6dB down from 50 to 100Hz. We do see the typical
6dB gain at the tuning frequency and the 40Hz dip is again room
related. It also looks like there is a standing wave right around 32Hz
too (notice how the different tuning points have peaks at the same
frequency). Also, the natural roll off of the original cabinet
shouldn't have a peak at 30Hz either. The higher tuning frequency is
getting masked by the room induced dip.

















Nevertheless, you can clearly see that you need at least 10dB of
attenuation down low. I think Dennis recommends around 6dB because
there is a peak around 150Hz that is about 4dB higher than the rest of
the bass bin's passband. With the EQ, you can expect cornwall-like performance except you don't have the 5dB rise at 80Hz.









Without
the EQ, you're talking marginal shifts in timbre. With the EQ, you
definitely have more bandwidth, but at what distortion increases? djk
recommends the K-43 instead of the K-33 in this application because it
has both better efficiency and more power handling (making the
distortion increases less dramatic).







It is definitely a very cool inexpensive mod, but it would be naive to
believe that it yields the best possible performance for the bottom 2 octaves.

I was in error... Dennis says -3 at 31Hz with a K-33, -3 at 28Hz with an EV DL15W.

Who did this mod that was measured? I don't remember seeing this chart before. The higher power handling of the K-43 is (to quote Dennis) a red herring. The K-33 can deal with 150W. Most people aren't coming close to that in their living rooms/dens/ listening rooms.

It is all about tradeoffs... he did say you lose some efficiency doing this mod...I still plan to do it at some point... probably with the cabinet underneath first, just to make it simple to test further.

Bruce

[DrWho]

-3dB at 31Hz with EQ unless I'm totally reading it wrong.

(peaking 2nd order highpass that takes advantage of reduced cone excursion at the tuning frequency).

This

is the first time that chart was posted. It is a graphical

representation of the data provided by Pete Fowler in this thread:

http://forums.klipsch.com/forums/thread/345616.aspx

(which seems to have been taken with a 1/3 octave RTA)

I really wish someone would provide better measurements of this mod. I

don't doubt anything that Dennis claims, but he never provides any

screenshots of his measurements, nor provides the manner in which they

were measured. At the same time I respect the fact that he's not

required to share anything in the first place so I'm not complaining.

It's just that Klipsch has tried this mod before and determined it

wasn't worthwhile...lots of reasons can factor into that decision so it

doesn't necessarily mean that it doesn't provide any acoustic benefits.

But knowing how inexpensive it is to port out the back of the HF

chamber, you really gotta wonder if the sonice benefits are there. It

seems like EQ is really the way to go with this mod and that's not

something Klipsch can expect their customers to do.

It's just way easier to judge the benefit of a modification when you actually have proof of performance.

[DizRotus]

The fact that Klipsch doesn't do it doesn't mean that it isn't a viable improvement; it could just mean that a business decision was made to not do it.<?xml:namespace prefix = o ns = "urn:schemas-microsoft-com:office:office" />

Look at some other decisions Klipsch made regarding La Scala:

four screws to attach woofer;

horns mounted to back of baffle board; and

18 gauge zip cord.

Would anyone seriously argue that:

using eight screws to mount the woofer;

flush mounting horns to the front of the baffle board; and

using heavier gauge wire are not relatively inexpensive "improvements?"

I don't fault PWK's "not a dime's worth of difference" reasoning when making commercial decisions, but I wouldn't draw the conclusion that Klipsch would have done it if it were an improvement. Thirty years ago I put backs on Speakerlab SKs, like Klipsch did on the Anniversary Khorns.

[DrWho]

I would argue that they are solutions to imaginary problems.