Legend Acoustics | Brand
Legend Acoustics
Reviews
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25.01.2022 Back to loudspeaker development this time of the floor-standing Kantu 12s, that are the top of our passive loudspeakers. The change from model 10 to 12 again involves using the new ceramic-coated tweeter but also entailed relooking at their crossovers to see if enhancements could also be made there. It is part of our continuous improvement of all our range. My hierarchy of importance of loudspeaker components for sound quality is: 1. the drivers that create the sound wave...Continue reading
23.01.2022 We have recently launched version 12 of our Kama loudspeakers (note there is no version 11 as it may be mistaken for Roman numeral 2)! The Kama 12s are similar to version 10 but use a new tweeter. It is the one we used in the recently released Tripos, our top-of-the- range passive stand-mount speaker. The tweeter has a ceramic-coated dome that combines the exceptional detail of a metal dome with the smoothness and non-fatiguing characteristic of ceramic. It has a copper ...Continue reading
20.01.2022 I thought changing the tweeter in the bookshelf Joeys to make them version 12 as I had done in the last post for the floor-standing Kamas would be a simple matter of again just changing the treble resistor to account for the tweeter’s slightly different efficiency. However as often happens in speaker design things don’t always turn out as expected! The Joeys are the babies of Legend’s monitor range with their name reflecting the ‘fast open’ sound of their Australian desig...n and build. The tweeter for version 12 has the ceramic-coated dome that combines the exceptional detail of a metal dome with the smoothness and non-fatiguing smooth characteristic of ceramic. And we have retained from the Joey 10 the excellent mid-bass unit made from very strong aluminium-alloy with ribs to further increase their strength to increase their pistonic range. However I was concerned when just using the Joey 10 crossover that, while it sounded great at low to medium volume levels, it could become a bit ‘brittle’ in the treble at higher volume levels, particularly on the very highest notes on a piano. There were 2 possible reasons. Firstly chaotic cone break-up distortion of the mid-bass unit above 5 kHz was not being sufficiently suppressed by the cross-over’s 2nd order 12 dB/octave low pass filter at 2 kHz. Or secondly the distortion of the tweeter at its lower frequencies caused by excessive movement (that quadruples for each halving of frequency and stresses suspension & magnet structures) was not being sufficiently suppressed by the cross-over’s 2nd order 12 dB/octave high pass filter. After quite a lot of investigation both were solved by moving to 3rd order 18 dB/octave acoustic filters. As shown in the first measurement graph of frequency response (FR) of the individual drivers, the first bass-mid break-up at around 5 kHz is now over 25 dB down; and the tweeter’s output is also 23 dB down at 1 kHz where its excursion becomes too great and its distortion to significant. The second graph shows their combined response has a very flat FR with total harmonic distortion (THD) well below 0.1% above 1 kHz. Importantly this was translated into the lack of treble ‘brittleness’ at higher volume levels. However it did lead some extra cost and complexity of building the crossovers on the back of the terminal plate (to reduce signal path and number of soldered component junctions) as shown worthy of Origami! But I think was worth it for the improved sound quality - and we have not increase the SRP of the Joeys. The other more minor change was to resistively load the port by placing some open fibre wadding behind it. This allowed the advantages of a port (deeper bass) but with reduced disadvantages (with tighter bass) and it gave a better tonal balance to the overall sound which I am now very happy about! More details can be found at http://www.legendspeakers.com.au/products-joey/
17.01.2022 As I mentioned in my previous post, turntable systems are just the inverse of speakers systems both are electro-mechanical systems, the former converting mechanical vibrations into electrical signals while the latter converting electrical signals into mechanical vibrations - and their problems/solutions are similar. So I was not very popular when working at Linn for saying that I did not believe in the hierarchy where turntables were the most important. I was also not very...Continue reading
12.01.2022 In my last post I described how I modified the Xover filters for our floor-standing Kantu 12 loudspeakers in the light of our new ceramic-coated metal dome tweeter. Because our Tripos loudspeaker is essentially the top 2/3 of the Kantu without the second bass driver and in a standmount cabinet it prompted me to relook at the Tripos Xover filters. Given no driver is perfect one must try to balance the non-linear frequency and total harmonic distortions of the drivers to f...Continue reading
10.01.2022 This post is about another great Australian hi-fi company, Dynavector Australia. Whereas Dynavector in Japan makes very high quality phono cartridges, Dynavector Australia makes very high quality amplifiers, and in particular a phono pre-amplifier, designed and manufactured here in Australia. I came across their phono pre-amplifier quite by accident recently when visiting DEQX in Sydney. Alan afterwards invited me to his home to listen to his recently purchased second-hand L...Continue reading
