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Advice for Beginners - consider this test from an audio club


ODS123
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6 hours ago, DizRotus said:

I have a pair of 30+ year-old DIY LS3/5a monitors with recently replaced networks from Falcon Acoustics in the UK.  While not an officially licensed pair, they’re made according to Falcon plans of the same materials and with the same KEF drivers as the licensed examples.

 

They were designed by the BBC to be portable monitors in the field.  As Bruce @Marvel said, they’re very inefficient.  They do sound excellent in small spaces at moderate levels.  Claude @ClaudeJ1 said he could understand the fuss about LS3/5a speakers after listening briefly to mine.

 

Personally, I feel they enjoy a cult status beyond their delivered performance.  My non-audiophile friends are ALWAYS impressed by the “large” sound from “small” speakers.  The attached photos are from the web, but mine look exactly the same.

 

I would not sell mine.  They have their place.

 

C63772CB-4406-455C-9916-3EF01B355769.jpeg

I heard these in the 70's along with a version by other companies including those by Irving M. Fried with his Transmission Line subwoofers. I also heard the Spendors. I thought both were overpriced and I had already build some Super Cornscalas in 1974 and was about to buy Khorns.  I was a DJ 3 years before Saturday Night Fever came out, so none of those "mickey mouse" speakers would have worked for me. Dynamic would NOT be a word I would use to describe their sound. Cohesive and smooth would be better terms.

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11 hours ago, ODS123 said:

LS 3A/5A...  A wonderful and timeless dynamic radiator speaker design. ...And a great many of its copies & iterations were constructed from MDF.

They were spec'd by BBC specifically to be 11 mm birch ply (other woods they tested were inferior for that size), beech bracing and heavily dampened.  The screws were even specified.

 

Rogers went out of business and was sold to a Swiss company before they started actually making them.  

 

There was a great Sterophile article about all of this I can't find right now.

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'For a speaker to be still available, virtually unchanged, 14 years after that date. Such is the case, however, with the $650/pair LS3/5a design, which is still popular well into its teenage. (Only a number of horn speakers from Tannoy and Klipsch have been around as long.)

 


Read more at https://www.stereophile.com/content/bbc-ls35a-loudspeaker-1989-rogers-version#ys8Eb4gOWpqeG3b4.99

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Thanks for the read, pretty interesting. I was also surprised to kinda agree with stereophile. When I had these I listened late at night, lower volume, maybe 80 some db. I also incorporated a sub and eq after a few days to get a fuller sound. If I lived in a 10 x 12 room full of stuff I could be pretty happy with em'.

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1 hour ago, ClaudeJ1 said:

Dynamic would NOT be a word I would use to describe their sound. Cohesive and smooth would be better terms.

 

Agreed.  Perhaps the OP meant to type "direct radiator," instead of "dynamic radiator?"

 

Did they have a bass peak around 80 to 150 Hz? 

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1 hour ago, dwilawyer said:

They were spec'd by BBC specifically to be 11 mm birch ply (other woods they tested were inferior for that size), beech bracing and heavily dampened.  The screws were even specified.

 

Rogers went out of business and was sold to a Swiss company before they started actually making them.  

 

There was a great Sterophile article about all of this I can't find right now.

 

You're correct Travis.  The battens are beech.  The BBC specs are attached below.  MDF not mentioned and would not have been acceptable.

 

BBC%20LS35a%20design.pdf

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1 hour ago, ClaudeJ1 said:

I heard these in the 70's along with a version by other companies including those by Irving M. Fried with his Transmission Line subwoofers. I also heard the Spendors. I thought both were overpriced and I had already build some Super Cornscalas in 1974 and was about to buy Khorns.  I was a DJ 3 years before Saturday Night Fever came out, so none of those "mickey mouse" speakers would have worked for me. Dynamic would NOT be a word I would use to describe their sound. Cohesive and smooth would be better terms.

 

Claude the IMF speakers had KEF B110 and T27 drivers but they were not built to LS3/5a specs.  There were many small 2-way speakers that used the same KEF drivers, but also were not LS3/5a speakers.  The BBC never intended these for DJ use; dynamic is not their strength.

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8 hours ago, DizRotus said:

I have a pair of 30+ year-old DIY LS3/5a monitors with recently replaced networks from Falcon Acoustics in the UK.  While not an officially licensed pair, they’re made according to Falcon plans of the same materials and with the same KEF drivers as the licensed examples.

 

They were designed by the BBC to be portable monitors in the field.  As Bruce @Marvel said, they’re very inefficient.  They do sound excellent in small spaces at moderate levels.  Claude @ClaudeJ1 said he could understand the fuss about LS3/5a speakers after listening briefly to mine.

 

Personally, I feel they enjoy a cult status beyond their delivered performance.  My non-audiophile friends are ALWAYS impressed by the “large” sound from “small” speakers.  The attached photos are from the web, but mine look exactly the same.

 

I would not sell mine.  They have their place.

 

C63772CB-4406-455C-9916-3EF01B355769.jpeg

I just noticed that the woofer has the same quibble in the cone as the original. It does not show up so much in my pics but they were the same. It seems like the color was even black/green hue

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8 minutes ago, Fish said:

I just noticed that the woofer has the same quibble in the cone as the original. It does not show up so much in my pics but they were the same. It seems like the color was even black/green hue

 

Are those your speakers in the photo I snagged from the Internet?  They certainly aren't mine, which are stored away and not easily photographed.

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31 minutes ago, garyrc said:

 

Agreed.  Perhaps the OP meant to type "direct radiator," instead of "dynamic radiator?"

 

Did they have a bass peak around 80 to 150 Hz? 

Yes, which limited there about to less than 90db because the woofer was working so hard, but the stereophile article I quoted said if you have a sub-cross it at 80hz iirc, you can go to 100 to 103 db.  

 

They are very finicky about room placement.  Can't be in corners, have to be out into room etc.  

 

Lots if measurements in the Stereophile article

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34 minutes ago, DizRotus said:

 

You're correct Travis.  The battens are beech.  The BBC specs are attached below.  MDF not mentioned and would not have been acceptable.

 

BBC%20LS35a%20design.pdf

P. 6, last paragraph, other hard woods found to have resonance in lf that resulted in coloration of sound.

 

15 ohms so a 100wpc amp is quickly 50wpc.

 

Travis

 

 

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https://en.wikipedia.org/wiki/Medium-density_fibreboard:

 

The name derives from the distinction in densities of fibreboard.  Large-scale production of MDF began in the 1980s, in both North America and Europe.

 

I clearly recall the particle board that was generally available as a plywood "substitute" through 1970s and would never have considered it for cabinet construction myself.  "Modern" MDF is quite different excepting superficiality.

 

It would be better had the referenced design document actually mentioned consideration of anything but plywood panels.

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1 hour ago, DizRotus said:

 

Claude the IMF speakers had KEF B110 and T27 drivers but they were not built to LS3/5a specs.  There were many small 2-way speakers that used the same KEF drivers, but also were not LS3/5a speakers.  The BBC never intended these for DJ use; dynamic is not their strength.

 

1 hour ago, DizRotus said:

 

Claude the IMF speakers had KEF B110 and T27 drivers but they were not built to LS3/5a specs.  There were many small 2-way speakers that used the same KEF drivers, but also were not LS3/5a speakers.  The BBC never intended these for DJ use; dynamic is not their strength.

Never had much interest then or now to pursue the details of that type of speakers. I didn't like what Mr. Fried said about PWK, and he struck me as a real shyster. I don't think his stuff had much lasting value as the others of that ilk, but I still don't care either way at this point in my career. I always like the bigger stuff!

 

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