In 1973 the OA-14 and the smaller model OA-12 was introduced. They were the first Carlsson speakers built as left and right. I.E. the first stereophonic speakers with the speakers more directed towards the listening position compared to earlier models that were omni-directional. OA-14 and OA-12 were thought of as budget versions of the more exclusive OA-116 and OA-2212. The OA-14 and OA12 were sold in large quantities, especially the OA-14. The electric circuitry is identical apart from the fact that the OA-12 uses 4 pcs of eig-ht ohms tweeters in parallel series whereas the OA-12 users two sixteen ohms tweeters in parallel. The box-volume of the OA-14 is twice as big as that of the OA--12 and therefore it has a deeper bass-reproduction. The bass-reflex port is conical which counter-acts chuffing noise. This is something that most other designers discovered first in the nineties! The speaker stand on soft feet integrated in the design, also in this area Stig Carlsson was ahead of the competition. The design is well thought through with thick baffles made from ABS-plastic and with three perforated internal reinforcement sections, also made from ABS-plastic. The mid-bass used is the SC165, a Peerless 6.5” eight ohms speaker specially developed for Stig Carlsson. It is tilted towards the listeningposition. The tweeters are the same as in the earlier models, the MT20HFC. The filter components were premium quality. The speaker was sold from 1973 until 1979.
The OA-14 is a two-way floorstanding speaker designed to stand with its back directly against the wall. It reproduces the classic Carlsson-sound, integrated and relaxed and has the same ability to remove the walls from listeningroom as the rest of the speakers from the seventies. They do not demand amplifiers with high current capability and can therefore be driven by cheaper amplifiers and still deliver a good and pleasant sound-reproduction. The soundreproduction from a restored / upgraded pair is both revealing and comfortable. An upgraded pair of OA-14 with the new Peerless CT62 tweeter can compete with many more expensive speakers The most obvious thing about the OA14 is its ability to make the walls ”disappear” in the listeningroom. With the old tweeters it sounds as if the speakers have a bit of a phaseshift. This is, as in all older models, most likely due to the distortion coming from the old tweeters, the distortion is preceding the reproduced sound and comes as whistling sound prior to that. Upgraded with CT62 tweeters the OA-14 is a very good speaker that can be enjoyed for years to come!
The OA-14 is easy to restore, most things follow the general description in ”restoring and upgrading”.
As with all old speakers you need to start with the woofers.
The tweeters are seldom damaged but an upgrading should be considered, see restauration and upgrading
Speaker terminals and internal wiring is well worth looking over.
Normally there are no problems with the crossover but consider changing the capacitor to a newer and better type, also consider if you need to use the jumper for adjusting the tweeters.
After being broken in for a few weeks the new speakers will reach their full capacity, they will reach even lower into the low range.
The OA-14 is also very suitable to use with valveamplifiers.
As all other models from the sixties and seventies the OA-14 shall be placed with its backside against the wall.
The biggest improvement on the speaker is to replace the tweeters with the new Peerless CT62.
See restoring and upgrading.
Since October 2001 we recommend a new set-up for the tweeters; the “Y-configuration”.
This will remove the distorting comb filter effect
For further information on this contact CarlssonPlanet
Terminals and internal wiring
We recommend changing the terminal to goldplated ones. Install these in the bottom of the box.
It is not possible to access the inside of the OA-14. The baseboard is made of ABS-plastic and is an integral part of the box design.
It is not possible to access the baseboard from above because of the reinforcement sections inside the box.
Instead You have to take the leads out through the bass-reflex tube and lead them to binding posts set outside the box with L-shaped brackets.
TECHNICAL DATA Sonab OA-14
According to Sonabs handbook and/or ”Hifihandboken”
Box volume: 35 litres
Measures: B x W x D: 23 x 57 x 42 cm
Weight: 11,5 Kg
Principle: Omnidirectional, bass reflex type. With increased quota between direct and reflected sound.
Diagonally facing mid-bass speaker. Four tweeters, two facing listening position and two diffusing /
Impedance: 8 Ohms
Frequency range: 25-18.000 Hz
Frequency response: 29-15.000 Hz ± 3dB placed against the wall.
Crossover frequency: 1800 Hz
Mid-bass: 1pc 6,5 inch 8 Ohms Peerless SC165.
Tweeters: 4 pcs 5 cm 8 Ohms Peerless MT20HFC
Finishes: Rosewood, walnut, teak and black or white lacquer.
1975: 1950 SEK per pair.
Second hand: 1000 up to 1500 SEK per pair depending on the finish.
Restored: If well restored up to 2000 SEK.
Restored and upgraded: With new tweeters (Peerless 62CT13 Prices ranging up even up to 6.000 SEK. They are well worth this.
Martin Dellstig - Co-Editor
This page was last edited 2012-01-28 15:20:21 by Per