TDL Studio 0.5 Bookshelf Loudspeakers Reviewed

Published On: February 13, 1990
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TDL Studio 0.5 Bookshelf Loudspeakers Reviewed

While the Studio 0.5 is a smaller version of the Studio 1, it still looks "commanding in the all-black finish." It has a "remarkably coherent sound" which matches the Studio 1 for consistency. Once the speaker is ideally positioned for bass, our reviewer advised listeners to "ready yourself for amazement..."

TDL Studio 0.5 Bookshelf Loudspeakers Reviewed

By Author: Home Theater Review

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Bass versus size — the age-old dilemma has been addressed in a number of ways, some successful and some (usually electronic) not so successful. And whatever the satellite system designers produce — hidden subwoofers, for example — British hi-fi enthusiasts seem to prefer one full-range enclosure per channel.

One of the best ways of squeezing a quart out of a pint has been the transmission line concept, a not-too-distant relative of the folded horn. Among the pioneers of this system was IMF, which metamorphosed into TDL, familiar to most readers for a range crowned by the huge Reference Standard. But TDL rewrote the books with the diminutive Studio 1, with a footprint and an overall space requirement matching that of yer garden variety two-way

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I have to admit that I was surprised at how well the Studio 1 worked, because I thought that the convoluted folds which make up a transmission line could be reduced only so far. But TDL has reduced the speaker even further — in size and in price — to produce a transmission line speaker tiny enough to be called ‘cute’.

Before saying any more, I want you to be aware of the two most  relevant specs if this review is to have any meaning. First of all, the Studio 0.5 has a footprint of only 200x304mm (WxD) and its height is a mere 620mm. Add to this the dedicated stands and you increase it by only 70mm plus spikes. Best of all, though, is the price — #399, plus #70 for the stands, the latter a perfect match in both sonic and aesthetic terms.

The Studio 0.5 looks like a junior TDL, a shrunken-down ‘minilith’ which still looks commanding in the all-black finish. The grille is black cloth stretched over a rigid frame, the
cut-outs large enough to preclude any edge diffraction. The box itself is finished in black ash veneer, with the back and baffle in black paint. With the grille removed, you’ll see at the top a
ferro-fluid-controlled 25mm magnesium alloy tweeter, protected by a mesh dome and featuring a separate rear chamber.

Below this, its bottom edge situated roughly half-way up the baffle, is a 135mm doped polypropylene-coned woofer, tiny enough to look like it belongs in a Celestion 3-sized box. It features a phase plug sprouting from the centre and utilizes a Kapton  former, vented pole magnet and cast alloy chassis. At the very bottom are the two ports for the transmission line.

The back conatins two pairs of hefty binding posts in a recessed  area near the top; they accept bare wire, spade lugs or banana plugs, although they’re too far apart for 19mm spaced pairs. Still, access is good and the barrels are large enough to provide  a good grip. The speakers arrive with solid core wire links, but bi-wiring offered such obvious improvements that I can’t imagine why anyone would be so tight-fisted as to run these in
single-wire mode.

In addition to the clever carpentry, the secret of the 0.5 is the use of the long-throw woofer, which offers high power handling to compensate for the efficiency loss associated with trying to extract deep bass from a small enclosure. The Kapton voice coil former contributes higher power handling by virtue of its ability to withstand higher temperatures. The use of this non-metallic material also increases the electrical ‘Q’ of the driver. The phase plug is fitted to improve the transition from the bass/mid driver to the dome tweeter.

The crossover point for the 0.5 is at 3kHz, accomplished by a simple 5-element design incorporating the aforementioned bi-wiring capability. Other ‘magic’ wrought on this speaker
consists of a nice, safe nominal impedance of 6 ohms and a reasonable but not high sensitivity of 85dB. I used the speaker successfully with the Musical Fidelity B1 to see how it would fare with a budget amp, while I tested its limits with the far heftier Counterpoint SA-100.

Other products in the review system included the Basis turntable with SME Series V arm, Lyra Lydian cartridge, California Audio Labs Tempest II SE CD player, Counterpoint SA-1000 pre-amp and wire from Lieder, MasterLink, Space & Time, Sony, Audio-Technica, plus a few I won’t name as they sounded unduly awful. The profusion of cables leads me straight to the primary curse which plagues this speaker.
Click to Page 2 for Setup, Critical Listening, and the Conclusion

Let’s not mince words, huh? This speaker is so inordinately fussy for
what should be an easy-to-use, upper-mass-market model that it will
challenge any inveterate tweaker to near-breakdown. Maybe it’s the metal
dome tweeter, still an ornery device regardless of
its genuine potential, or maybe it’s the strange dispersion pattern —
whatever, this speaker needs as much fine-tuning as any megabucks
dipole, so don’t expect to just slap a pair on the floor for maximum

For starters, the 0.5 teeters on the edge of brightness, despite the
copious amounts of bass which prevent it from sounding lightweight or
top-heavy. If you used these in a blindfold test,
I’ll guarantee that your buddies will think that they’re hearing
something the size of an Isobarik or a KEF 105. But this rich bottom end
doesn’t counterbalance a tizz which leads you to an
array of cables for fine-tuning purposes. Unless, of course, you’re
lucky enough to have a dozen amplifiers and sources at your disposal for
producing a better match.

Item 1: Solid core and/or thin strand wire — both of which I’ve
always though were lousy, desperate solutions of the
two-wrongs-don’t-make-a-right variety — aggravated the situation so
much that I even substituted short lengths of my preferred multi-strand
cable when assessing the speakers in single-wire form. I didn’t want to
gut the 0.5s to find out what was inside, but I wouldn’t be surprised if
it was solid core and/or thin-strand.

Item 2: Positioning is hypercritical, and not just in terms of
toe-in, or proximity to the walls. More important than either is the
amount of tilt you settle on, adjustable via the stands which
have spikes long enough to allow you to tilt the 0.5 back by a few
necessary degrees. This is entirely dependent on the distance between
the speaker and your listening seat, and it’s as critical as the tilt
factor of the Apogee Stage. The only way to accomplish this is by
enlisting the help of a friend or two, so you can bark out orders from
the hot seat. But it’s worth it.

Once you’ve eliminated the potential for tizz, you’re treated to a
remarkably coherent sound, the bass-to-mid-to-treble transitions
matching the Studio 1 for consistency. Don’t ask me
why, but the speaker sound smoother when bi-wired, despite splitting the
crossover, which does suggest that the links are inordinately critical
when you’re using a bi-wireable speaker in
single-wire mode. That inch or two of solid core…yecchh.

The bass quantity is tuned, as expected, according to the proximity
to the walls. I wouldn’t advise raising the speaker (above the level
provided by the dedicated stand) as a substitute
for the tilt, because the height off the floor via the stand is ideal
for bass quality, especially control. The tilting accomplishes one
thing, focussing the image for more accurate and
therefore three-dimensional portrayal; although raising the speaker so
that it fires at ear level would accomplish the same, it will
compromise the bass. So, just as with the legendary
Hadcock arm, addressing one area of set-up is bound to butcher the
perfection you’ve attained in another. To repeat myself:persist with the
dedicated stand.

Once the ideal postioning has been achieved — and I’d offer more
advice, but this can only be done by ear and in the actual listening
room — you can ready yourself for amazement. Now I am not trying to set
you up for an experience akin to listening to a tower full of Infinity
12in drivers, or a JBL Everest, or a Duntech. But you’ll find that
little can touch this baby at #399
when it comes to weight, slam, mass — whatever you’re looking for if you’ve embarked on a quest for more bass.

Regardless of what you think makes a speaker sound ‘big’ — the mass
provided by deep bass or dispersion which fills the space in front of
the listener — you’ll be pleased to note that a
painstakingly installed pair of 0.5s can mimic some real monsters. Image
height, when gauged from the listening seat with the tilt just so,
isn’t quite as convincing as with a pair of
Divas. But the 0.5, positioned with the tweeter some 6in below the
height of my LS3/5As, matches that of my favourite BBC-approved giant
killer. Stage width extends beyond the edges, as it should; try it with
the James Boyk microphone test CD for proof. And depth? This baby could
fool you into thinking it’s a thoroughbred dipole.

But however good the spatial characteristics, the smooth midband and
the clear treble (assuming you’ve paid heed to what I’ve written above),
it’s the bass quality which lifts this wa-a-ay above like-priced
competition. Given that you’ll hear these in a shop where the staff has
taken the time to set them up with the ludicrous amounts of attention
they demand, you’ll be staggered by the extension, the solidity and the
control. There’s no fat at all when you’re in the hot seat, though — and I know this sounds weird — they sound as flabby as an Isobarik off axis.

What the Studio 0.5 will not do is tempt those who think that
controlled bass must be as tight as a drunk on New Year’s Eve. The
Studio 0.5 is rich, not dry, and the harmonics on acoustic
bass are liquid and flowing. What happens when you play bass derived
from a keyboard hooked up via MIDI is that the edge is softened. I
consider that a virtue, because it may even fool you into thinking that a
musician rather than a computer operator made the recording, but those
weaned on MC Hammer won’t be amused. Fine, let them stick their heads in
the bass bins down at the club.

I’ve gotta say it: my fetishistic love for the LS3/5A
notwithstanding, I feel that the TDL Studio 0.5 is the best speaker you
can buy for under #500. And if you add the stands to the #399, for a
total of #469, you’re left with #30 to buy that extra length of cable
for bi-wiring while staying below the half-grand mark. If this speaker
doesn’t win some industry kudos, then the Oscars and the Booker prize won’t stand alone as warped awards.

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