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La Scala Bass Reflex Mod


sootshe

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There's no damping material in the doghouse. I would think it would make the build difficult to remove the rear panel. Then you would have to remove the ramps and then the baffle with the slot in it.

Attached are drawings with measurements taken from multiple LS to get close to the real deal.

What woofer is in yours?

Bruce

Was told by the builder the woofers are the same that came in the originals, once I'm ready to go will address everything.

Honestly these speakers now are more than impressive before I change much inside will first get the boxes built the holes cut in the doghouses and give them a test drive.

Having the LS drawings makes me all the more anxious to dive into this project. It will have to wait a while presently restoring one of our Heathkit W-5M tube amps. Our summer season is approaching fast with a wife that likes being busy,no complaints I have a lot of things to keep me occupied besides trying to keep up with her.

Will certainly continue putting together all the info I need to tackle this project once the season changes. One thing is for certain will plan on previewing a pair of original LS.

Thank you again for all the great info.

Mike

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Also wonder about changing the speaker wont it be acting a bass reflex with the doghouse vented?

Yes, it will act like a bass reflex but at the same time a horn. In my opinion it is a win win. I would not own another pair of Lascala without the port mod.I tried both port lenths, 10"and 7", the 7 inch was the clear winner for me.Dave

+1 :emotion-21:

Edited by DizRotus
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Hi mdross and welcome

Let me introduce myself - I am the current owner of these speakers

I have made some tweaks to the bass box to suit my components and the listening room

Let me just answer a question you posted above regarding the access hole in the dog box - as you are building a custom cabinet you will still require the hole as it's your only way to fit and remove the bass driver

And if you want a listen you need to come to Australia ;)

I proceeded to rework the insulation inside the bass cabinet section

The previous owner Sootshe had it fully lined with fabric covered fibreglass insulation

This was carefully removed and vacuumed cleaned to give me a blank canvas to work with

Sound testing without insulation was first tried to get a ball park idea of what was required and it displayed some reverberations in bass output

I used my go to motor room insulation that I have had success with on my other speaker builds

The only sections that were insulated was the - sides, back and top ceiling area with the bottom and front left bare

Also a couple of insulation strips at the port pipe entrance and finally added recently some 400mm X 200mm plastic air balloons 3 per tube

The diference this mod has done to bass delivery and definition is nothing short of amazing

I dont have any testing equipment My ears and senses tell me that it easily gets to below 30 htz ( The Crites bass driver is rated @ 26 htz ) However after the cab tweaks - the bass produced is so crisp & fast, very defined without muddiness

Hope that helps

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Edited by Full Range
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Hi Full Range and thanks,

It sure does help if it were not for the spring and summer season that's finally blossoming all around us I would be tearing into the Speakers. I'm so hoping my custom cabinets are true replicates of LaScalla's outwardly they are exactly the same. No matter I'm still going to build the base boxes and do the same thing you have done let my ears be the judge.

The air ballons in the tubes sure is interesting, reading these posts is so inspirational. May not be able to wait till fall. Once the tube amps are up and running will at least tear into one of the LaScalla's and see what I have.

Mike Ross

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Fullrange,

Where and how do the airbags go?

Inside the port tube from the front - so if the mod did not work, the air bags would be easy to remove

At first tried to roll 3 of them together but only 2 would fit

So in the end I placed 2 rolled together and placed in length wise snugly and the other one followed across and delicately squeezed in so it fitted snugly

The previous owner had made some foam disks to fit inside the port tubes - they were reused

Here are a couple of photos to view

post-57741-0-95860000-1397686678_thumb.jpost-57741-0-31940000-1397686707_thumb.j

Edited by Full Range
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The breathable foam I understand, the bags? Not so much.

Dave

To tell you this truth I didn't think it would make any diference

It was just an experiment after reading about the late speaker builder John Wyckoff

He used bubble wrap sheets in his design the Super 12

I may not like it in a month and if that is the case, they can be easily removed - but all I can say now, is the speakers sound wonderful

But there is a difference in a good way and it's subtle

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Without knowing what is inside my outwardly look a like LaScalla's and they sound incredible I might add. Before I dive into this project maybe it would be a good idea if I had a base test on their present state of tune. How do I measure the output to get this base reading?

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Instead of porting a LaScala and getting Direct Radiator bass and increasing distortion, why not just greatly extend your bass AND midrange by building a QuarterPie with your K33's. It's only time and lumber, right? Talk about a sonic improvement! Keep everything else the same, heck you can even use the LS bottom as an empty stand for the K400/K77 top end. LOL. Just pull your woofer, build a QuarterPie for $80 out of MDF!

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Edited by ClaudeJ1
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Better yet, the guys with the commercial versions that have K-43's will have even better perfomance without buying new woofers. Porting is a cool mod, I agree. But if you are going to all that trouble, of making sawdust, you may just want to try a bigger horn with lower distortion all around, better bass slam, AND better midrange too. I'm just sayin'.post-20774-0-33580000-1397845339_thumb.j

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Instead of porting a LaScala and getting Direct Radiator bass and increasing distortion, why not just greatly extend your bass AND midrange by building a QuarterPie with your K33's. It's only time and lumber, right? Talk about a sonic improvement! Keep everything else the same, heck you can even use the LS bottom as an empty stand for the K400/K77 top end. LOL. Just pull your woofer, build a QuarterPie for $80 out of MDF!

attachicon.gifLaScalaVsQuarterPieK33.jpg

Where would you put the 1/4 pies then... On their sides next to the La Scalas?

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Where would you put the 1/4 pies then... On their sides next to the La Scalas?

Underneath

Wouldn't it be better to put the 1/4 pies on their side so as to 1: conserve space, 2: have the mids and tweeters at the stock heights?

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Where would you put the 1/4 pies then... On their sides next to the La Scalas?

Underneath

Wouldn't it be better to put the 1/4 pies on their side so as to 1: conserve space, 2: have the mids and tweeters at the stock heights?

IndyKlipschFan has all splits and puts milk crates under his tops. So under will raise the mids to a better height

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1/4 pies are new to me and would enjoy knowing all there is to know. What are they,how do they add to the sonic pleasure?Have been toying with building a pair of WE SATO horns along with the ported bases and love the smell of sawdust.

Check out his Q-Pie thread. Very interesting. I'd possibly be interested myself but need to cross over at 500 Hz.

Paul

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