I designed the Signature 50 speaker for LSA quite a few months back but it’s finally starting to roll off the assembly line and will be shipping soon.
It’s a 6.5in 2-way bass reflex that uses a premium 28mm silk dome tweeter, and I gave details of some of the measurements earlier in the What’s on the Bench Tonight thread.
Predicted response of crossover:
Step response is quasi transient perfect (inverted due to mic response):
Custom crossover uses inverted passive Harsch topology of my design. All high quality parts like pure copper wire inductors, and custom made film caps and non inductive wire wound resistors:
Impedance as function of frequency shows a true 8ohm speaker with lowest dip at 6.5 ohms above 20Hz:
Here is the measured response (yellow) overlaid with the predicted response (blue) based on raw measurements from in-cabinet measurements of the drivers to account for driver offset and cabinet diffraction.
And here is the measured harmonic distortion as a function of frequency - measured at 2.0Vrms and 0.5m:
You can listen to the first sound test here:
First review is now in from Tone Audio:
https://www.tonepublications.com/review/the-lsa-signature-50-speakers-2/
It’s a 6.5in 2-way bass reflex that uses a premium 28mm silk dome tweeter, and I gave details of some of the measurements earlier in the What’s on the Bench Tonight thread.
Predicted response of crossover:
Step response is quasi transient perfect (inverted due to mic response):
Custom crossover uses inverted passive Harsch topology of my design. All high quality parts like pure copper wire inductors, and custom made film caps and non inductive wire wound resistors:
Impedance as function of frequency shows a true 8ohm speaker with lowest dip at 6.5 ohms above 20Hz:
Here is the measured response (yellow) overlaid with the predicted response (blue) based on raw measurements from in-cabinet measurements of the drivers to account for driver offset and cabinet diffraction.
And here is the measured harmonic distortion as a function of frequency - measured at 2.0Vrms and 0.5m:
You can listen to the first sound test here:
First review is now in from Tone Audio:
https://www.tonepublications.com/review/the-lsa-signature-50-speakers-2/
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What is the 6.5 speaker on the LSA signature 50? And is there an 8" version? I'd like to build a base/stand
like the Pearl Graphene by Joseph Audio, for the LSA Signature 50's that I recently ordered. Thanks.
like the Pearl Graphene by Joseph Audio, for the LSA Signature 50's that I recently ordered. Thanks.
For the Signature 50, the 6.5in woofer is an OEM for LSA, no equivalent brand for a commercial off the shelf driver exists. On the LSA Signature 80, the driver is the Dayton RS180-8. Thanks for ordering the Sig 50’s! I am not sure what you mean by adding a stand with 8in drivers? That would require redoing the Sig 50’s with a high pass so that they only handle the midrange and above?
How does the Harsch crossover work in this application without a substantial physical offset between the tweeter and woofer centres?
By using a high crossover frequency (5.5kHz), the offset distance is smaller - but still not enough which is why it’s called an inverted Harsch, the tweeter polarity is flipped. This gets the time alignment just about right and the overall step response looks like a right triangle with a negative leading edge overshoot.
Very nice cabinets! 👍
Is the midbass polarity negative also, as the tweeter? If that is true, what will happen (sound wise) if you flip polarity of both drivers together, to get positive triangle?
Is the midbass polarity negative also, as the tweeter? If that is true, what will happen (sound wise) if you flip polarity of both drivers together, to get positive triangle?
Hey folks, a new review from Audiophiliac on the LSA Signature 50’s. Funny how it seems to be quite appropriate following the head banging rocking above.
I was looking at your website and I was interested in purchasing these speakers with the matching stands but didn't seem to find an order page.
Unless it is right in front of me which means of course I missed it. 😀
I don’t think there is a link to buy the stand. You can request it through a phone call to Underwood HiFi when placing your order.
You can buy the stands from Wally. It's on their site as well.. https://www.underwoodhifi.com/products/lsa-speakers (right below the first pic).