ONKYO QuartLam-III

Commentary

A floor-type speaker system using the QL system.

The QL system applies the principles of flute and Yokobue. It uses an ALT (Acoustic Loading Tube) installed at the back of the speaker to resonate the sound emitted from the back of the speaker at the speaker at frequencies corresponding to 1/4 of the length of the tube, and efficiently reproduces low frequencies. The structure of this type of enclosure looks similar to that of a backload horn. However, the mounting position of the unit differs between the QL type and the backload horn. In the QL type, the unit is installed in the middle of the tube.
In the QuartLam III, the tube length is designed to be 1.8m, and the resonance frequency at 1/4 wave length (lowest resonance frequency) is 47.2 Hz, which is the lower limit of the lower range.
In addition, as a resonance tube, resonance occurs at frequencies of integral multiples with a minimum resonance frequency of 47.2 Hz. In order to prevent this, measures are taken such as changing the thickness of the tube by tapering the partition plate, attaching an appropriate amount of sound absorbing material to a part of the tube, adjusting by installing a tuning port, and selecting the mounting position of the speaker strictly. These measures reduce the Q and prevent disturbance of the response.

The low range is equipped with W-1608C which is a 16 cm cone type woofer.
In this unit, light and long fiber cone paper and highly compliant urethane Ω type roll edge realize bright and rich bass reproduction. In addition, the magnetic circuit uses large magnet of 100 mm diameter and voice coil of aluminum foil bobbin of 30 mm diameter to improve damping and linearity.

TW-825A/TW-825B 8 cm cone type tweeters are mounted in the high range.
These units have different edges, fixed edge and free edge respectively. This gives different characteristics even with the same 8 cm aperture. By shifting the responsible band and overlapping with the stagger, the high-frequency reproduction capability is enhanced.
The network structure is also independent of each other.

Equipped with a level control on the rear surface, the level of the tweeter can be switched to 3 levels.
In the Minimum position, Tweeter 1 is cut.

Hard particle board is used for the enclosure, and the thickness of the front baffle is especially thick.

Model Rating

Method	2-way / 3-Speaker / QL System / Floor Type
Units Used	For Low Range : 16 cm Cone Type (W-1608C) For High Range : 8 cm Cone Type (TW-825A, TW-825B)
Playback frequency band	47 Hz to 20 kHz
Max Input	40W
Output sound pressure level	94dB/W/m
Impedance	6 Ω
Crossover frequency	1kHz
Level control	For high frequency, 3 steps
External dimensions	Width 240x Height 730x Depth 380 mm
Weight	13.5kg