Floor-standing Speakers

Legend Acoustics Tikandi Speaker System with DEQX HDP-3 Processing

ARTICLE INDEX

Design

The Legend Acoustics Tikandi loudspeaker is one of a new generation of loudspeakers that is designed to be used only with a digital processor. The Tikandi consists of two pieces: a small "pod" containing the tweeter and midrange, and a larger bass module containing a pair of 10" woofers. Traditional binding posts are provided for the pod, while the bass module uses a Neutrik speakON connector. While the Legend looks normal from the outside, inside there's something different. No passive crossovers. The pod has two pairs of binding posts, one directly wired to the tweeter and the other directly wired to the midrange. The speakON connector has 4 conductors, with each woofer wired independently. The system was provided with a complete set of Exakte loudspeaker and interconnect cable with the proper connectors. The loudspeaker requires at least 6 channels of amplification, but that would require the two woofers to be wired in parallel, presenting a minimum 1.7 ohm load to the amp. In this system, a Marantz MM8003 8-channel amp was used, with each of the four woofers powered by its own amp channel. This is one possible amplifer option. You can buy the system without amplification and provide your own, or soon you'll be able to get the system with DEQXs new 4-channel digital amplifiers.

Legend Acoustics Tikandi Loudspeaker System with DEQX HDP-3 Processing

Legend Acoustics Tikandi Loudspeaker System with DEQX HDP-3 Processing

The 8-channel amp is driven from the 6 output channels of the HDP-3 processor. RCA T-connectors are used to split the low range output of the HDP-3 in two for driving the 4 bass amplifier channels. At that point, the magic starts. The HDP-3 processor has 6 channels of analog outputs (single ended, and two types of optional balanced outputs). One single ended and one balanced analog input are provided (digitized at 24 bits and 48 or 96 kHz), along with both coaxial and AES-EBU (aka AES3)digital inputs (also compatible up to 24 bits and 96 kHz). The HDP-3 processor provides 3 functions, apart from serving as a DAC, an ADC and Preamp........ . The preamp volume control is fully analog and the channels are matched to 0.1 dB. First, the HDP-3 performs loudspeaker driver correction. Each loudspeaker driver is measured using a time-gated tone sweep. This tone sweep is generated by the processor and played through the system. A microphone connected to the processor then listens to this swept tone.

The HDP-3 then computes a correction to produce a flat driver response in both frequency and phase. This measurement is typically made with the microphone close to the loudspeaker to avoid room effects. The woofer offers two setup possibilities: The drivers can be measured in the near field, and then have room correction applied later, or the driver can be measured from the listening position, correcting the driver and the room simultaneously. Second, the user (or professional installer) sets up the crossovers. Several different crossover filter types can be used, including Linear Phase, with crossover slopes from 12 dB per octave up to 300 dB per octave. Once the drivers are measured, their response can be analyzed using the DEQX software, both to verify the correction, and tune the crossover points and slopes to best match the driver response and integration. One important tool is the ability to see the time domain response of the drivers, allowing the user to add time delays to get perfect driver time alignment.

Third, after the crossover and driver measurements, the microphone is moved to the listening position so room measurements can be made. The results of these room measurements can then be used to set the parametric equalizer function of the HDP-3 to provide room correction. Unfortunately, the parametric EQ cannot be set independently for the two channels; one PEQ curve is applied to both the right and left channels simultaneously. The parametric EQ can be set either automatically or by hand. The HDP-3 can store 4 separate configurations, with different crossover settings, driver correction settings and parametric EQs. One is typically used as a bypass with only the crossover function implemented, although it can be set to anything.

The description above is actually a simplified one. The HDP-3 software gives the user control over every last detail of the crossover, driver and room correction process. This is a double-edged sword, though. The learning curve is rather steep. But this is not a problem because all Tikandi systems come with professional installation, so the owner doesn't have to concern themselves with all the details unless they want to. I personally love that kind of thing, but many owners will just prefer the professional install.

If you have lots of other analog sources (turntable, tuner, SACD player etc), or you want to integrate the system with a home theater, the small number of analog inputs could be limiting. This can be remedied with an analog switch like a Manley Skipjack, but that will run you an additional $700. There is no built in phono preamp. Also, for HT integration there's another issue. The total time delay through the HDP-3 is a bit over 20ms, although in some configurations it can be as low as 8ms. You will want to be able to dial in that much delay into your surround sound processor's center and rear channels to match the Tikandis. I could not do that with my old fashioned Rotel SSP. The delay mismatch wasn't so much that it was clearly obvious, but the 20 ms difference between the center and the FR and FL was definitely reducing the precision of the sound when watching movies. With a newer SSP, with a wider range of delay options, this won't be a problem. I also found the lack of a Toslink input rather annoying. I use a Mac laptop as my music server. It has a 24/96 capable optical digital output. For use with the HDP-3, I had to get a USB or firewire sound interface with a coaxial output, or use a toslink to coax converter. I did the latter, using a M-Audio CO2 bidirectional toslink to coax converter. This unit is completely asynchronous, so it should add little additional jitter. The HDP-3 completely regenerates the sampling clock driving its output DACs anyway, so the effect of clock jitter at the input of the HDP-3 should be nil.

Legend Acoustics Tikandi Loudspeaker System with DEQX HDP-3 Processing