what is soo unique about LS3/5A? Is it the crossover which makes much of the difference?

Nostalgia and historical significance.

And mysterious BBC dip. Though modern measurements eg. CTA2034A will probably show that it improves the power response.

speaker designers who have had the original and built modern variants eg. John Krevskovsky and the late Jeff Bagby have shown that modern drivers and modern tools for crossover design can make the for a batter 5L minimonitor speaker better


2011-04-29 8:37 pm
I do hope the modern ones are less coloured than the originals.
The last time i audioned a pair, they were kind of boxy sounding.
Mine are definitely not boxy or colored sounding, but they must have an excellent tube amplifier
to sound their best, in my experience. Some versions are not the best examples, though.
Last edited:
I modeled my homage to them by copying the step response as close as possible. I used a much simpler crossover, less expensive drivers, and set the crossover frequency higher. A member on SBAF (Inoculator) who had the LS3/5A’s did an A/B comparison and liked what I did. My crossover uses 6 components and the LS3/5A has twice that.
My step response:

LS3/5A step response:

Everyone who has built this loves the sound. They do have a very natural, non fatiguing way of recreating a beautiful midrange and when used as a bookshelf speaker with a rear wall in a smaller room, have a surprising heft to the bass. Complete plans are in the thread.
  • Like
Reactions: 1 users


2012-02-10 12:12 pm
Looking at the fan following of the Ls3/5a why is it soo famous? ... what makes the sound soo special?
The same thing that makes any other product being held in high regard, well executed advertising. That the engineering behind LS3/5 is sound, is beyond any doubt. There is quite a few people fishing in this pond to achieve the same. At least they are trying to.
well executed advertising.
from the wiki "A total of 11 companies were ever granted licences by the BBC to manufacture the model". With 3 making it at any given time according to the wiki.

With the creator, there are 12 possible advertisers. It is no wonder it is "famous".

Looking at the fan following of the Ls3/5a why is it soo famous? The crossover also doesnt look like conventional 2nd order or 4th order.

What is this all about? It could be some BBC standard ok then so what? what makes the sound soo special?
Here is Mr. Jones on the topic.
  • Like
Reactions: 1 user