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Photo of La Scala II with speaker grill removed


Tizman
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Hi All.

 

Just wondering if anyone has a photo of the La Scala II without its speaker grill?  I am curious to see how the mid-range and tweeter horns are terminated at their mouths on the LS II, and haven't been able to find a photo online.

 

Cheers,

Tiz 

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You can find the video re the Museum Edition on YouTube and also the third subject on the forum.  Plus as a bonus you get to hear two fellows speaking in the anechoic chamber and a lapel microphone.  Most of the photos of the original LS has the grill cloth removed because they were made that way.

 

WMcD

 

 

LSII and Tony Martin.jpg

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  The pics above are as good or better than mine. I was confused by the cutout in the motor board and the size of the K77D. 

  The K77D is really not terminated, there is a gap around the edge of the mouth. The K400 is rear mounted, the motor board is straight cut and a little rough in finish. 

  Was told that the tweeter cut out is sized for the old style K77 with Z brackets. It also allows a little wiggle room due to the proximity of the Mid Horn and the top of the cabinet. 

 One member mentioned fabricating an adapter flange to allow mounting the older style K77 horns in a La Scala ii. I think the project is in evaluation phase to judge potential demand. So far the market size is two adapters.

  I would also like to try the larger style horn and a B&C DE-10. But there is no way. The K77D is a tight fit. 

  The termination of the mid horn mouth could be implemented better too. Continued flare and a machined surface. 

  Both drivers play great by my ears. I overthink the details sometimes.

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Thanks for the replies and photos.

 

I have been doing some reading lately about horn mouth termination and it’s impact on measured horn performance and subjective listening.  

 

I own a pair of 1976 La Scalas, and have wondered why they have a straight cutout for the midrange and tweeter horn instead of having the transition be bevelled to follow the angle of the horn’s mouth.  Given the wavelengths in each case, this would seem to be a bigger issue for the tweeter horn, but is not ideal in either case. This is based upon what I have been reading online.

 

I was wondering if the LS II corrected this.  It looks like it is made in the same way as the older LS.  The transition from horn mouth to the room is straight, and thereby interupts the expansion of the horn with a constriction and a small lip at a point where it would be best to have either a bevelled motorboard matching the line of the horn, or this bevel in addition to a rounded termination of some sort.  

 

They say that a little information can be a bad thing, and I am a relative newbie with respect to horn speakers, so I may be off base about this.

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I just finished watching the video referenced by WMcD (thanks!), and it looks like the termination of the tweeter horn in the LS II is better than in my LS.  The tweeter horn is surface mounted in the LS II.  The midrange horn termination in the LSII is the same as the LS.

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4 hours ago, Tizman said:

I own a pair of 1976 La Scalas, and have wondered why they have a straight cutout for the midrange and tweeter horn instead of having the transition be bevelled to follow the angle of the horn’s mouth.  Given the wavelengths in each case, this would seem to be a bigger issue for the tweeter horn, but is not ideal in either case. This is based upon what I have been reading online.

 

I "feel" what you're saying.  At the least in order to lessen diffraction it seems there should be a generous radius on the outer edge of the hole.  Continuing the horn flare would serve to increase the size and length of the horn - to benefit or detriment?  Front-mounted, inset the depth of the flange would seem to be best for function.

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9 hours ago, Tizman said:

I just finished watching the video referenced by WMcD (thanks!), and it looks like the termination of the tweeter horn in the LS II is better than in my LS.  The tweeter horn is surface mounted in the LS II.  The midrange horn termination in the LSII is the same as the LS.

 I am far from an authority on horn termination. The tweeter on the LS ii looks worse the the mid. The mid changes to straight at motor board. 

 The tweeter is flush mounted but has a gap all the way around. If the hole matched the K77D I would think it would be an improvement in function and cosmetically. 

  But it sounds great regardless. 

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so far as the K77 goes it does not know that the gap exists, the tweeter does not "see" the gap it does not radiate to the gap, all that comes out of the tweeter horn is confined to within the horn profile. The only real issue you may have is to how it looks. As to the K400 mounting behind the baffle it is not a big deal. The baffle cut out simply presents to the horn mouth as a very short parallel section of the horn which provides zero expansion. It does not really do anything good or bad, as PWK used to say about it compared to mounting flush "it does not make a dimes worth of difference". Paul was not 100% correct about this but the difference between a unit like yours and a flush mounted horn is not very much. Given the option I would prefer a flush mount horn but I would not say no to a used set at a good price which were rear mounted. The difference between the two comes down to small additional reflections from the mouth. This is not a night and day difference. Many people do not even hear the difference. At the time Paul did not consider it worth the effort to go to the trouble and the added cost to flush mount and it was more of a marketing choice rather than one of performance in the end to make the switch.

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I wouldn’t modify my La Scalas, but I will go to the effort of terminating the horns better in future DIY speaker builds that include horns.  It’s a matter of many small differences adding up to larger ones.  That’s why I asked about the LS II.  Perhaps the termination isn’t audible.  I wonder if anyone has modified their La Scalas to create a better transition, and have measurements or listening impressions to share?

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pull the tweeter and mount it onto a piece of wood then slide the tweeter back so that you align the diaphragm of the tweeter to the diaphragm of the mid horn that will make for a significant improvement in sound quality. This will be a much more significant difference that what you would hear between a flush mounted mid horn and a back mounted mid horn.

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