Frequency response of the Sampan FTL with TL-ABC

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Frequency response of Role Audio Sampan FTL

Frequency response: 35 Hz to 20,000 Hz, +/-3.5 dBs.
Big picture

This on axis measurement shows the Sampan FTL with Transmission Line Acoustic Bass Contouring (TL-ABC) has a frequency response of roughly 35 Hz to 20,000 Hz, +/- 3.5 dBs.  As an indication of the usable "in-room" frequency response that can be achieved with room reinforcement, the minus 10 dB response of the Sampan FTL is 27 Hz. This frequency response is unprecedented for a loudspeaker that uses a 3 inch transducer, weighs 3.7 pounds, and has dimensions that are 4 X 8 X 9.5 inches.

How the measurement is derived

Using the DRA Laboratories MLSSA acoustic measurement system, the measurement is a weighted average of the Sampan FTLs transmission line vent's nearfield frequency response, the Sampan FTL's driver's nearfield frequency response, and the Sampan FTL's farfield frequency response.

The transmission line vent's nearfield frequency response is taken with the microphone placed just inside the edge of the vent. The driver's nearfield frequency response is taken with the microphone placed as close as possible to the cloth covering the baffle and driver without touching it. The loudspeaker's farfield frequency response is a single reading taken one meter from the front baffle on the drivers axis.

The nearfield measurements of the transmission line vent and the woofer are weighted and spliced together and the resulting bass response curve is then spliced to the loudspeaker's farfield frequency response.