tls80 review : Stereo Buyers Guide

Product report : IMF TLS 80 Monitor

Stereo Buyers Guide

The TLS-80 speaker system is a domestic version of the acclaimed IMF Professional Monitor.


Like its professional counterpart, the TLS-80 features full transmission line loading - the rear end of the bass driver being exhausted into a tapered and filtered passageway. The midrange driver is also contained within its own short line preventing intermodulation and colouration from return waves reflected from the back of the cabinet.

Both a tweeter and a supertweeter are employed for proper handling 'conducive with wide dispersion', according to the manufacturer.

The TLS-80 is fitted with a three position `perspective control'. In the central `O' position the mean hemispherical response is nominally flat, whilst the '-' position tailors mid band energy to provide a response which psycho-acoustically increases the effective distance of the listener from the transmitted performance.

Similarly in the `+' position the mid and high frequencies are brought forward to provide a response relating to a close listening position, such as to enhance some popular music performances, especially under high ambient noise.

From a technical viewpoint the TLS80 incorporates a 300mm x 210mm flat polyster bass driver, a 150mm plasticcone midrange unit, a 45mm diaphragm tweeeter, and a 19mm dome super tweeter. Crossovers are at approximately 375Hz, 3.5kHz and 13kHz.

The TLS-SO is a freee standing system measuring 978mm(H) x 460mm(D) x 456mm(W) and supplied in a mirror image pair.


Bass response is very extended but doubling is evident at the low extreme.

Midrange frequencies were very smooth and pleasant sounding, but tended to be swallowed up by the powerful bass. The high frequencies are very well maintained with a nice clean `shimmering' quality.

Transients were handled superbly and the majority of musical pieces reproduced very faithfully. Clarity is excellent and colouration is mostly very low.

Test Results

The response graph shows a 50Hz - 15kHz - curve ± 6dB and the peak at 65Hz confirms our impressions about the bass response. This could however, be tamed by correct placement and amplifier tone control adjustment.

Distortion was minimal and impedance is nominally 6 ohms.


This is an impressively large speaker with performance to match its size.

IMF Monitor TLS-80 Suggested Price: $1610 Distributor: International Dynamics Agencies Pty.Ltd.