TL7 O transmission line kit
The TL7 O is a mid-size, tapered, single-fold transmission line speaker kit. Our TL series uses modified SDX7 woofers matched with the OW4 Hiquphon Platinum dome tweeter or the optional RA104.5 ribbon. The TL7 O places its drivers in an MTM configuration, mirror-imaged, with OW4 Hiquphon Platinum dome tweeters.
What to expect: the bass is very tight, not boomy, with in-room response below 24 Hz, and the midrange and higher frequencies are very well balanced. The crossover is 3rd order at 1700 Hz.
Frequency range
15 Hz – 40 kHz · log scaleThe kit includes
- 4 × SDX7 XBL² drivers (modified cone treatment)
- 2 × OW4 Hiquphon Platinum dome tweeters
- Solen (Mundorf) capacitors, 16 gauge air core inductors, metal oxide resistors
- 2 terminal cups with custom terminal posts
- Wire, screws and poly damping material
- Cardas lead-free silver solder
- Cabinet construction plans, plus a CD with complete construction photos of the cabinets, the crossover layout plans with photos of assembled crossovers, and veneering and finishing information
Recommended cabinet
- Rear ported, tuned to 27 Hz: 44" tall × 9" wide × 19.25" deep
Measured
Responses were taken at 1 meter, showing the crossover point at 1650 Hz.
Impedance: an easy 4 ohm load with a small dip in the upper range, which is still no issue for most 4 ohm amplifiers (measured with the optional impedance correction network).
Off-axis horizontal measurements were taken at 15, 30 and 45 degrees, along with an unsmoothed spectral decay plot.