TDL RTL-1 Studio Monitors

Foam on acoustic baffle removed by previous owner ---ding on one corner (see pic) Monitor compares to PMC / Tannoy with extended low frequency response via reflex transmission line. Mids are forward but smooth. These are excellent, neutral and natural performing monitors.

The TDL RTL 1 are full 'reflex transmission line' loudspeakers, yet within enclosures sufficiently small to be considered bookshelf speakers.

Equally suited to that position, or placed on stands, they possess the sonic stature and power handling of much larger speakers.

Indeed, the aural illusion of the RTL 1 is of far greater sound sources, thus making them an ideal complement for the RTL 2 or RTL 3 in a surround system.

Amongst other speakers, the TDL RTL 1 should be the first to be auditioned.

Specifications

Type: 2 way, 2 driver loudspeaker system

Frequency Response: 35Hz to 20kHz

Recommended Amplifier: 20 to 80W

Crossover Frequency: 3000Hz

Impedance: 8Ω

Sensitivity: 87dB

Bass: 1 x 172mm loaded polypropylene cone

Tweeter: 1 x 19mm soft dome

Enclosure: reflex transmission line

Finish: black ash, rosewood

Dimensions: 390 x 200 x 220mm

Weight: 16kg

 "Transducer Design, Ltd. (TDL), based in Buckinghamshire, England, specializes in making transmission-line speaker systems. The company, founded in 1969, makes quarter-wave reflex transmission line speakers, such as the RTL 1, and larger, half-wave models. Like infinite-baffle and acoustic-suspension designs, halfwave transmission line speakers are configured to absorb the output from the rear of the woofer cone. The bass driver’s rear wave is directed through a tunnel whose length equals a half wavelength of the lowest frequency to be reproduced. The tunnel, which often is tapered, is usually folded and filled with an absorbent material, such as long-fiber wool. In quarter-wave reflex transmission lines, the tunnel’s length is one-fourth the wavelength of the lowest frequency to be reproduced. The back wave is not completely absorbed, emerging from the tunnel to ten force the woofer’s front wave. Several advantages are claimed for transmission-line systems. They are said to produce good output at very low bass frequency. TRANSMISSION LINE SPEAKERS CAN PROVIDE GOOD LOW BASS FROM SMALL WOOFERS. They enable the use of small woofers, whose output can thus extend into the mid frequencies. And their enclosures are inherently very well braced by the tunnels inside them. The RTL 1 ,s a two-way system, with a 1-inch dome tweeter and 6-inch cone woofer made by TDL. It is designed to be placed on a bookshelf or mounted on a stand. The enclosure (including the partitions forming the transmission-line tunnel) is made of medium-density fiberboard, % inch thick except for the 3/4-inch-thick front baffle, and is finished in black wood-grain vinyl. A small amount of Dacron is behind the tweeter, but there is no other absorbing material inside the cabinet except at the tunnel’s exit. That exit, at the bottom front, is divided into two openings with open-cell foam grilles. The foam is intended to help limit the woofer’s excursion at very low frequencies by restricting airflow in and out of the openings. The front of the enclosure, except for the tunnel openings, is covered by a grille of acoustically transparent black stretch cloth with a snap-off plastic frame. The input terminals are near the top of the rear panel. Five-way binding posts are provided for the crossover’s high- and low pass filters, which are normally connected by gold-plated metal straps. By removing the straps you can hi wire or biamplify the RTL 1; this might be advantageous sometimes, such as when long cable runs are required. The red and black posts of each pair are spaced 34 inch apart to accept standard dual-banana plugs; the two pairs are on shelves, angled at 45°, for easy access. Rated Frequency Range: 35 Hz to 20 kHz Rated Sensitivity: 87 dB SPL at 1 meter, 2.83 V rms applied. Rated Impedance: 8 ohms. Recommended Amplifier Power: 75~400W"