At the Melbourne AV Show, Australian Hi-Fi magazine’s Edgar Kramer caught up with Legend Acoustics’ proprietor and chief engineer DR Rod Crawford for a brief impromptu conversation re the new Tikandi Grande Be flagship speakers…
Dr Rod Crawford: The Tikandi Grande Be is my attempt to crystallise the last 20 years of commercial speaker design including the stuff at Linn. Basically the Tikandi Grande Be takes our original design to another level essentially by adding a dedicated bass/midrange driver which operates roughly from 150Hz to 450Hz. That takes the pressure off the other drivers. One of the problems with the 3-way Tikandi is that the drivers are operating at the limits of their range; you’re pushing them as far as you’d like and sometimes even a bit further, in terms of trying to keep them linear and without break-up and all the distortions that come with that. But that is a bit of a compromise. Adding that extra driver, making it a 4-way system, allows us to use a much more dedicated midrange/upper midrange driver free of where many drivers start to cause problems above 1kHz-2kHz where the ear is most sensitive. They start to break-up where, in terms of music, you hear a hardness or brightness to the sound. That’s avoided with a dedicated driver. The Grande Be has two 12-inch drivers firing in opposite directions to cancel cabinet vibrations.
Edgar Kramer: And it’s an active system, no passive offered?
RC: Purely active at that level. Each driver requires its own amplifier channel which is expensive but the advantages are that the drive units are directly driven which translates to very low distortion, great detail and massive dynamics, things that are compromised in passive crossovers.
EK: Can you tell us about the drivers used in the Tikandi Grande Be?
RC: The Beryllium tweeter is a Scanspeak with the multi-pole magnet structure. The Beryllium allows it to go to a higher frequency without break-up. In fact, I think the break-up is somewhere around 40kHz and doesn’t come back down unlike aluminium and other tweeters which seem to break-up a bit above 20kHz and there’s debate as to whether it feeds back down into the hearing range. The improved magnet structure allows it to go down quite low with 0.1 percent distortion which is lower than some good valve amplifiers in the 1kHz range. We use it down to 2kHz and it’s incredibly smooth across the range.
EK: Did you test a whole lot of tweeters, like ribbons for example?
RC: Not for this speaker. I’ve tried ribbons in the past… I’m a bit of a heretic… I have problems with ribbons from the theoretical, measurements and listening sides. I think that with ribbons, once you start them moving they don’t stop moving as quickly as a rigid dome. Yes, they are light but they rely on that stop and start with air damping and viscosity. It’s like a drum, once you hit it keeps vibrating until it dissipates all its energy. That’s just the theory. In terms of music, I listen to a lot of classical music, the ribbons can sometimes sound hard with strings. Mind you, in real life that’s how strings can sound. Not the old gut string instruments but the modern steel stringed ones where you get a massive crescendo with 30 violins playing together and with the modulation Between them the sound can get quite hard. Some planar speakers soften that; some people like that but the problem also is that you lose dynamics in percussion and electronic instruments. With some slow-decaying musical instruments the ribbon’s effect may be quite pleasing. It’s nice sugar but too much can be annoying.
What I like about the Tikandi Grande Be is that they can play all sorts of music and the tweeter is very accurate. And that massed string section can still sound great if the recording is good. This is a very accurate speaker with extremely low distortion and it will expose inadequacies in the rest of the system chain.
The Tikandi is now controlled by DEQX and the DEQX has an extraordinarily good USB stage so at the source level it’s excellent. But like I said, it all comes back to the recording.
EK: So apart from low distortion and the active configuration, what were you looking for as far as the new speaker’s sound and how do you balance measurements with listening tests?
RC: I’m looking for the speaker to actually get out of the road. Most speakers have some sort of ‘character’ and that’s almost a given with this type of device. I’m trying to achieve a speaker that disappears. Again, very low distortion and linear drivers combined with the crossover and correction accuracy of the DEQX. It’s a very flat frequency response and a very linear phase response too and those things are markers of a very good speaker. I accept that there may be things that we can’t or don’t know how to measure when it comes to speaker design but if you get those things right technically you’re heading in the right direction in terms of neutrality and accuracy. That was my aim.
“There is nothing so practical as good theory and understanding.”
When designing a speaker I regard it as a problem to be solved, within certain constraints like price, size, application etc. As the price goes up the constraints usually come down, as with the Tikandi Grande Be. This understanding, built from knowledge of the physics, materials, acoustics etc, illuminates my choice of drivers, cabinet shape, crossover points, etc. This is for all the speakers I design, including the Grandes in which I thought about the small weaknesses of the Tikandi and how to solve them. However, as I said in a recent SNA post the scientific and technical process is like a train needing two tracks in sync to stay on the rails; theory, understanding and measurement. But of course even though the process is problem-solving, the aim and end-point is hopefully enjoyment of music, for me and others. Obviously this involves lots listening to lots of different types of music, from solo piano, guitar, etc through to small scale ensembles such as jazz and pop, to heavy-duty rock and orchestral. This takes around 80 percent of the development time and is the most pleasurable part. So with speaker development one actually needs three parallel tracks; understanding, measurement and listening!
I guess because the DEQX is so accurate and quick at changing things you spend less time going backwards and forwards as you would when designing passive speakers. Like experimenting by changing a crossover component when trying to control a subjective rise in the sound in the upper mids, for example. Even though I loved doing that at Linn. Linn had a great dedicated room, which you could lock from the inside and I’d spend the morning listening to music! I couldn’t spend the day just measuring, I’m a physicist, a big picture guy. I’m hopeless at detail.
Having said that, I’ve made contact with musicians and other ‘good ears’ to help provide second opinions because you tend to become too involved and focused and you lose objectivity.
EK: Are there any plans to trickle down the Grande Be’s technology to the rest of the line-up?
RC: Not really. We started with the truncated pyramid enclosure construction with the isobaric standmount which you reviewed. It’s an expensive construction process so we won’t be trickling it down to the entry level speakers. But the flagship speakers give us a benchmark to aim for on the lower ones.
EK: Sonic trickle down rather that technical?
RC: Yes, exactly. I’m going back to look at the rest of the speakers in the range after signing off on the Tikandi Grande Be. Looking at the Kurre 8. It was the first Kurre that got an Australian Hi-Fi Award. It was hard to beat but fairly expensive at $3.5k back then and a lot of Australians won’t spend that money on a local speaker. I’ve virtually gone out of home theatre but I’ve kept a centre and a sub. We just launched the Kantu 8 which was our first speaker nearly 20 years ago now. It uses that same Eton ceramic coated magnesium midrange as used in the Tikandi Grande Be. It’s the best midrange I’ve come across and the equal to an Accuton I listened to a few years ago which was incredibly expensive and very fragile. I would have loved to use it. This new driver has those qualities, especially the clarity which I’ve never heard since the Accuton. I like pistonic drivers while other designers like soft drivers like ATC and Proac use. Neither is right or wrong, just different and I’m for the pistonic ones.
For me, speaker design is partly a science and partly an art. It’s an artistic expression of my personality.