These and a pair of original LEAK's (15 Ohm) were the "little buddies" of our LEAK LT10 tube amplifier - sorry but the amp and original LEAK's have found new homes already.
BACKGROUND RELEVANT TO THESE SANDWICH 300's
Historically significant design and considered at the time to be very good loudspeakers. They still do themselves proud although loudspeaker design has moved on from 50 years ago!
Designed and components supplied by H.J Leak (England) but assembled here in Australia (Sydney) due to the high demand for the LEAK Sandwich range in Australia, their appointed agents were Simon Gray Pty Ltd (see the advertisement, this company was your "one stop shop" for all high quality audio products in the day)
A lot of this high demand was created by the audio industry, LEAK were (and still are) considered as a very respectable "name" and known for innovative design technology.
The "big brother" Sandwich 600's were widely used in the broadcast industry as monitor loudspeakers, particularly the Australian Broadcasting Corporation.
There is a LOT of background information on H.J LEAK (Harold Leak who was later joined by his son) online so I won't repeat that info BUT I will try to "fill in" some detail about this specific Australian assembled model ....
Let's get on with the description!
H.J LEAK - Stereo (Two) Loudspeakers
Circa 1970's
Assembled in Australia
Model: Sandwich 300
Rear identification badges (Serial # 2L/11710) *** See COSMETIC CONDITION FOR A NOTE ABOUT THE SERIAL NUMBER
Configuration: 2x 2.5" Drivers 1x 6" Woofer SEALED (NO porting)
Nominal impedance: 8 Ohm
Speaker terminations (rear)
DIN standard (1x flat pin & 1 x round)
Spring loaded hard wire connections (NO facilities for banana plugs)
Nominal crossover frequency 900Hz
Design frequency range: I cannot determine with accuracy the figures for these 300's, they sound great but ...
The Australian print advertisements do not state the frequency range, even in the technical specifications
The UK print advertisement just says "the beauties are capable of reproducing any sound fed into them, faithfully and with perfection" Now that's are very non-useful technical description!
An American print advertisement indicates these are "good" from 50Kc (Hz) to at least 12.5Kc (12500Hz) and then "beyond normal hearing" - also very vague claims.
I no longer have the original manual but I am sure that the professional music/audio industry would not have purchased these in droves based on the very wishy washy technical description above!
I have let my ears (tired as they are now due to age) do the evaluations, my rather nice test equipment has long found new homes - I am left with just my ears and really isn't that what good speakers are all about - forget the technical mumbo jumbo (although I like that!) but it's the listening experience that REALLY MATTERS.
Power handling 18 Watts RMS per channel
CABINET:
Particle board finished with Walnut (SEE COSMETIC CONDITION NOTES ABOUT THIS COLOUR) veneer (REAL wood veneer not plastic!)
18mm thick particle board used throughout (sides/front/rear/top/base)
Brushed aluminum front frame
Heavy cloth front grille (push fit into the frame)
Name badges fitted (both) - these are all metal AND rotatable NOT glued.
Floor standing design although we used these in various configurations, even laid side by side on a studio console surface. This is where fully rotatable name badges come in handy. This side by side configuration is also why ONE cabinet has the 4x felt pads on what would normally be the top! The felt pads are not difficult to move around anyway.
DIMENSIONS:
280mm Width x 500mm Height x 260mm Deep
WEIGHT: 11Kg EACH CABINET
OBSERVATIONS:
I hear you! WHAT THE....!
It must be realised that 50 year old speakers will most likely need some tender loving care, particularly in areas such as the crossover network capacitors (they do go "out of tolerance" over time) and possibly other little "tweeks" to improve the loudspeaker performance.
So that the new owner can really see what condition these are in (I feel that it is almost certain that these Sandwich 300's will be shipped so no viewing would be possible) I am including copious amounts of photographs which I hope will help out someone who is considering these little beauties.
The major thing I noticed is the lack of glue used by H.J LEAK! So many contemporary loudspeaker designs use glue EVERYWHERE and it is a real nuisance if there was a need to "clean up the old girl" - these Sandwich 300's don't have that problem!
REAR:
Plastic bucket (Black) is used to house the DIN and spring loaded terminals.
Wiring is a bit of a "rats nest" and the gauge of wire used is not large but then, these are 18W RMS speaker systems we are talking about, not a high current situation but then I looked at the crossover inductors and they are very "meaty" and capable of handling far more than 18 Watts RMS.
All internal connections are soldered direct to terminals, no spade connectors used here!
Rear panel (matt Black finish) is permanently fixed to the cabinet, non-removeable
UNDERNEATH:
4x White felt pads fitted (glued) to the base on one cabinet and the TOP on the other. Move them around as needed. The current felt pads measure 26.25mm diameter x 5.5mm thick - uncompressed.
INSIDE:
Off (out) comes the woofer.
LOTS of thick fiber wadding but loosely packed
Peeking down inside I can get a "birds eye" view of the crossover network.
3x large inductors - I have not measured these but it is unlikely they have gone "out of spec"
1x ELCAP 4uF
1x ELCAP 12uF
1x ELCAP 25uF
1X DUCON 8uf (40V NP)
SPECIAL NOTE: It is highly likely that these capacitors are now out (probably well out) of specification and would need replacing by modern "good quality" capacitors - not a difficult task but one that should be undertaken.
Hard wired point to point and on a baseboard which is removable from the cabinet
FRONT:
Very strong brushed aluminum frame around the front edges, welded corner joins. This frame is easily removable (Philips head screws), such as would be required for a cabinet restoration.
Push fit cloth covered grille (tight but not too tight - use a thin blade to prise off the grille e.g a knife (do not use a SHARP knife or you risk damaging the cloth covering!)
Metal LEAK badge top left hand corner (both loudspeakers) - attached on the inside by a metal clip. These badges are 360 rotatable.
WOOFER:
Wow! So very hand crafted and unique!
This clearly shows the "piston action" sandwich cone construction developed by LEAK and obviously made by hand. The magnet is SQUARE and measures
Frame measures 203mm diameter
Cone measures 155mm diameter (this is the cone diameter, the part that actually pushes air around)
Magnet 68mm
NO identification marking to the rear at all - this surprised me a little.
I have NOT cleaned the rear of the woofer, you can see a light grey "powder" all over the rear of the Woofer - this looks to be due to oxidisation, it rubs off with a cloth but I decided to leave it well alone.
Gentle cone movement does not reveal any "rubbing" or off centre problems.
DRIVERS:
Frame measures 85mm square
Cone measures 70mm diameter
Magnet diameter 68mm
ALL drivers sit in a Black plastic "well"
On the front of each driver is a very fine, Black fabric dust cover protecting the voice-coil.
When shining a very bright light inside, it appears these are the purple cones, its a bit tough to tell due to the dust cover but I can see "splashes" of purple around the surround, the cone and right into the voice-coil area
Solder terminals
COSMETIC CONDITION:
Out of 10 I would give these an 8 for cosmetic condition
All cabinet work is sound (no bulging particle board from moisture!)
Wood veneer finish is NOT seriously damaged, a couple of chips (rear corner(s) mainly) I have taken photographs of the WORST areas
Some superficial scratches to the veneer, NONE are so deep that they go right through the veneer!
ALL corner joins are sound and NOT separating
The strangest thing is the colour of the veneer! These originally came in Ash, Walnut and Mahogany finishes. One cabinet is definitely Walnut but the other cabinet is much lighter in colour. I have no idea what has happened here, we only had one set of Sandwich 300's so why one cabinet is such a different colour is beyond me!
If the new owner was to be restoring these (which I am not going to do!) it would be sensible to take out the speakers and rear terminal well, remove the front aluminium frame, give it a good Walnut or Mahogany stain and finish with a nice matt/satin finish. They would then look "as new" and real "show ponies" for any home or studio environment.
I did see two "dings" in the aluminium frame near the base, these are not major dents and in no way do they affect the integrity of the frame - it is the correct shape, true and without bending.
Rear spring loaded terminals move freely, no sticking. These are suitable only for small diameter speaker cabling, my test cable was just 2mm diameter core, solid conductor.
DIN sockets have been cleaned and were also checked (fine) when testing the loudspeakers.
BOTH front cloth grilles are in very good condition - absolutely NO holes at all (or even loose threads)
BOTH cloth grilles are clean and the same colour! The material used in heavy cloth and it is tightly drawn over the front panel.
BOTH front grilles fit into the frame nicely (push fit, held by friction only but there is no way these will fall out)
*** Only one cabinet has the complete serial number showing (metal label) because the other cabinet label is intact BUT only half of it is there!
On the rear panel and the front baffle you may notice little flecks of Black that are missing - that was caused by me opening up the loudspeakers to look inside, that Black paintwork is not very stable and the particle board easily comes away leaving the white/yellow of the board underneath. This also supports my notion that no-one has looked around inside these loudspeakers for many many years!
Loudspeaker cones are ALL in great condition, although I truly cannot view the driver cones because of the dust covers.
Those wonderful Woofer cones look great ALTHOUGH I did notice some rubber issues right out around the surround of both Woofers - rubber splitting. These splits are on the very outer edge of the surround which is an area where there is no cone movement at all but it does indicate that the rubber is beginning to fail after all these years. Rubber is one of the biggest problems in old electronic equipment e.g cassette decks, Oh dear, don't talk to me about rubber belts! I have lightly applied some "rubber rejuvenator" to slow down the breakdown process on these Woofers.
TESTING:
Woofer: DC resistance 5.5 Ohm ***
Driver (Left hand): DC resistance 5.3 Ohm ***
Driver (Right hand): DC resistance 1.3 Ohm ***
Rear terminals DC resistance: 5.5 Ohm ***
*** Both loudspeakers have identical measurements at the above points
*** Note that of course these are DC readings and NOT impedance
*** It is highly likely that the driver measurements (in particular) are being influenced by the crossover network)
EAR EAR EAR - WHAT DO THEY SOUND LIKE?
Keep in mind that the crossover is probably not splitting the frequencies correctly due to those ORIGINAL capacitors, I have had these running all of last week (warm 'em up) at low and medium levels, keeping in mind that 18W RMS is really as much as you should be pushing into these.
I ran my loudspeakers Left and Right separated, meaning one side was the LEAK Sandwich 300 under test and the other side was either my nice Aaron's (Australian Northern NSW manufacturer) or my Dali's (Denmark)
No matter what those condition those crossover caps are in, I was stunned! Here is a loudspeaker system 50 years old and damn she sounds good! On the up side I liked the "detail" very much, I felt it was better than either of my own speakers - I played classical, guitar (acoustic) and nice percussion pieces to check out how these sounded. All drivers are working fine and the same goes for the Woofers. I particularly liked the "sound" of the Woofers with low frequencies such a kick drums - a very realistic sound! I feel the "low end" response isn't as good as my Aaron's or Dali's but hey! this Woofer is a baby size quite frankly and the crossover frequencies (the capacitors mentioned above) are most likely way out of wack, the comment I found in an American advertisement (mentioned above) is probably quite true, don't expect great bass response below around 50Hz.
I used various drive levels to see how the speakers coped and no issues here at all, in fact I felt they enjoyed being pushed just a bit hard! I mean by this that they seemed to "brighten up" a bit when pushed at higher levels.
Having these sit in my storage units for the last few years, I am amazed at how these perform without having any updating to components. I did see online that others who have changed their capacitors get startling results for their time spent - I strongly encourage the new owner to do the same.
OVERALL OBSERVATIONS:
Although I am very happy that the components are all originals, and in very good condition, it's a pity that none of them have identification markings!
I do believe that prior to us getting the speakers (I am sure we would remember "digging inside" sometime in the past) someone has professionally and skilfully been inside - Why do I think this?
The speaker securing screws on each cabinet are different i.e one speaker uses slot heads on the Woofer and the other Philips heads. One speaker has plain silver grey finished screws whereas the other speaker uses Black screws.
One driver has a different shaped rear - "chopped" off at the sides.
Wiring to the Woofer/Drivers is colour coded on one speaker cabinet but the other cabinet wiring uses much more ordinary looking "figure-8" interconnecting wire which is not colour coded.
Crossover(s) have definitely not been touched in 50 years! While this MIGHT seem a good thing, I am absolutely sure that replacing these capacitors with "decent" equivalent values will bring renewed vigor to the loudspeakers - something like a "SOLEN" would be a great choice. Something with high tolerance, stability and a great reputation in the weird and wonderful world of audio.
FINAL NOTE (Yes I do actually stop somewhere ....)
Shipping these around Australia, safely and insured, is NOT a problem.
Due to my policy of FREE SHIPPING (around Australia) over orders over A$75, there is NO SHIPPING CHARGE when shipped within Australia
I will have to use a Courier service as Australia Post will NOT accept these (exceeding their weight limits)
If by chance the new owner wishes to pickup the loudspeakers from Rooty Hill NSW (Western Sydney area) this saves me time, packing and Courier costs and by entering the code LEAKPICKUP, the asking price is automatically reduced accordingly. This code is only eligible for those who wish to pickup these speakers!
