INTRODUCTION:
For many years we had a pair of speakers designed and created by the multi-instrumental, progressive rock musician Bo Hanssen from Sweden.
Sure there are great loudspeaker systems made by "backroom boffins" who only deal in the technical details of loudspeaker creation but any musician wants that "sweet" sound and in Bo's case, if you can't find it then you produce it yourself.
Bo had the philosphy of creating high-end loudspeaker systems but at affordable prices! Depends what you call affordable, these were still VERY expensive systems in their day.
Sad about the choice of trade name (SINUS), perhaps it means something different in Swedish!
SINUS was Bo's early venture into "better sounding" loudspeaker systems before morphing into RAUNA of Sweden, then Bo went off on his own (creative artist differences with his partners - happens a lot in the music industry) and was the driving force behind Opus-3 and other systems such as the CaveRex, Okko, Huggin & Munin - watch out for these names, loudspeakers that will astound and surprise!
As luck would have it, Bo was getting set to ramp up production and it all ended very suddenly with his sad passing away in 2011.
If you find this sort of information fascinating (I do!) then take a look HERE for more nitty gritty (no dirt band) on Bo Hansen and his exploits in the world of audio.
So what happened Russ? (I hear you ask, head cocked to one side and one eye closed!)
I was offering our complete A 103D system but not much interest once people found out how much it would cost to have them shipped! Bo made the cabinets extremely sturdy and the result was loudspeakers that felt like they were made of steel!
I waited and waited but the "right person" didn't appear from the mists, I have now decided to use these lovely old A 103D's as a component farm - sad but at least someone else can proudly say "Mate, I have Bo Hanssen inside my speaker system ... listen, you can hear him playing!"
So hear we go with this SPARE PART for the SINUS A 103D (or your own custom loudspeaker design) .... Read and enjoy
In brief, the A 103D was rated at 100W RMS per channel, presenting a 4 Ohm Impedance load to the audio amplifier
The configuration was 3 way - Bass, Mid Range and Tweeter.
The sound was "nice", while not truly in the audiophile class they sounded quite OK to us and I liked listening to them very much. But with these speakers it is not just about the sound but more about the fact that here was a loudspeaker designed by an accomplished musician! I like that ...
SINUS (Bo Hanssen) - A 103D Loudspeaker System SPARE PART ONLY
Part: Mid Range Loudspeaker
Made in Sweden
Circa 1970's
Part #: 0465D
Each loudspeaker (I have two) has a production number (948) on the rear magnet label
Impedance: 4 Ohm
150mm x 100mm OVAL cone
Voice-coil is an open design - no dustcover is used
Cone looks to be paper based (ribbed) with NO rubber surround
Basket is all metal, partially enclosed
Solder tag for wiring (no spades used here!)
DIMENSIONS:
Oval metal frame is 154mm across (at the widest point) x 103mm height
Mounting holes are spaced in each corner, 120mm apart horizontally and 92mm apart vertically
Front to Rear (including the magnet) depth is 65mm
Voice-coil diameter 14mm
COSMETIC CONDITION:
CLEAN ***
SPECIAL NOTE: While they might be clean now, when removed from the cabinet(s) they were not! Why? The reason is that the cabinet was FILLED with small foam rubber or fibre small cubes or pieces packed LOOSELY. Even though this speaker was sitting in a plastic "bowl like" well, some dust from that filling made its way to the rear of both mid range speakers. I had to spend quite some time very carefully cleaning out all this dust but now they are nice and clean.
The manufacturing label on the rear of the magnet is discoloured - it is NOT a moisture marking but after 50 years, something has caused this discolouration, which is the same on either speaker being offered.
BOTH Mid Range loudspeakers being offered have CONE DAMAGE!
Now while you might say, "Oh No that is very bad" - well, audibly I did not hear any significant issues when I listened to the system one last time (playing Bo's vinyl of course!) but it would be a good idea to either cement or "patch" the cone in the near future. Re-coning may not be an option due to the shape and specialty of this oval loudspeaker. If you search online, there are LOTS of different ideas and products for the professional repair of paper based loudspeaker cones.
EXTENT OF CONE DAMAGE:
Speaker One: very small hole or cut right up on the outer edge of the ribs, 3mm length. Manual operation of the cone (gently pushing and releasing the cone) showed no cone movement issues and no noises from the voice-coil movement (which would happen if misaligned)
Speaker Two: this is a true "tear" in the paper cone, extending 13.8mm out towards the inner ribs and then moves 18mm along the ribs. Again I manually operated the cone gently and the tear does not separate, cone movement "looks" and feels normal and no noises from the voice-coil movement.
As stated above, I (and my staff) never noticed a dramatic issue with the sound quality produced and in fact until last week when I removed the daggy old Green cloth front grilles and opened up the loudspeaker cabinets, I never knew these mid-range drivers had any issues!
TESTING:
While working fine in the past, up until last week prior to dismantling, I like to check the speaker characteristics immediately AFTER removal (to ensure no electrical damage has occurred when removed/desoldered)
EACH speaker measures 4.2 Ohm DC voice coil resistance (NOT impedance) and 0.06mH inductance
*** Where the photograph shows multiple loudspeakers, this advertisement is for ONE SINUS loudspeaker only - not all that are shown! ***
This loudspeaker has now been placed "cone down" onto a stiff cardboard backing and sealed within clear plastic to protect it until a new owner is found.
