My Story Tannoy Monitor Gold 15" (LSU/HF/15/8) were on my wish list since I
discovered coaxial speakers and the theory behind putting two
drivers on one axis. Couple of years ago I have become a lucky owner of these beautiful drivers. They were bought
from London, from the first owner who in 1968 bought them in Lancaster enclosures.
The gentleman used them in his private recording studio for couple of years during 70s. Afterwards, drivers were taken
out of the enclosures, with an intention of building better enclosures. This has never happened, and for over 30 years these
drivers were waiting for me in storage.
When I first plugged in these monster drivers in hardly
optimized test cabinets I was very impressed with their sound. And this was done using crossovers with old electrolytic
capacitors. Many hours of
soldering and even more hours of
working after, and I was able to test these drivers with
crossovers based on very good quality components and in heavy,
sand filled, 25mm thick plywood, 210l bass reflex enclosures.
More about building of these can be found in DIY section of this
As you gathered by now, I bought these drivers without any
enclosures so I was not able to review any particular model of
vintage Tannoy speakers that use Monitor Gold drivers (for
instance Lancaster or York). Nonetheless, from what I have
heard, Tannoy enclosures from the basic range are not very rigid
and people who buy them, sooner or later replace them with
better quality DIY cabinets. Having heard monitor gold drivers
in many different closed and bass reflex enclosures, I am
confident that enclosures used for this review allowed the drivers
to show their character and basic sound qualities.
Tannoy Monitor Gold 15in are the largest (and
most expensive) drivers in the Monitor Gold range. The "Monitor
Gold 15" is a common name, but their factory model name is LSU/HF/15/8. They were are successors to Tannoy Monitor Red
15, and were first launched in 1967. The reviewed pair is from
1968, therefore, from the second year of production. These
drivers feature unique 'Dual Concentric' construction (visible
on the scan of the sales brochure above), which ultimately means
that we have two drivers (tweeter/bass) combined in one driver
and working on the same axis. This itself would not be so unique
as there are many other coaxial drivers out there, however, in Tannoys, the tweeter diaphragm is placed behind the driver's
magnet and the same magnet is used to power both - the bass and
the tweeter diaphragms. Furthermore, the tweeter diaphragm is
positioned in inverted phase. The airwaves produced by it travel
through the PepperPot phase plug, and then, they are
'acoustically amplified' in the metal horn throat (inside the
magnet) and finally 'amplified' further by the bass diaphragm,
which acts as a horn extension. Horns can usually be fond in the
PA speakers, however, there are number of HiFi manufacturers
that use horns with very good results (e.g. Klipsch, JBL,
Altec, Lowther) and Tannoy is one of them. This is a rather
basic description, but it gives a good overview of how these
drivers work. People who are into DIY may find it strange, that
a heavy paper cone (LF unit) is crossing over with the efficient
HF unit at 1kHz, as this contradicts with best practices that
can be found in many speaker building books. But, it works, and
it works rather well! Having two diaphragms on one axis (in
theory) should result in better pin point imaging than in
traditional speaker designs, as the whole frequency range
originates at one point source of sound, not from two or three
different drivers placed somewhere on the speaker face.
Couple words about history... Tannoy Monitor Gold range was very
popular in the recording studios,
in 1970s. Many famous studios (including Abbey Road in London) used these speakers for mixing
- check the photo of the right, found somewhere on the internet - pair of Tannoy Lancasters, presumably with MG15 inside.
Numerous legendary albums were mixed using these speakers, so if you have
a pair at home, you may be hearing the recording in a very
similar way to the person who mixed it (this isn't always a good
news though ;). Also, I have found something that indicates that
some of the recording studios may have been using these speakers
in more modern times. The photo on the left is an inner front cover of
the Marchin' Already album by Ocean Colour Scene.
Looks familiar? Recording was made in 1997. Apart from studio
monitoring, these drivers were also used in higher end of domestic
market. They were used in large horn loaded enclosures like GRF,
GRF Professional and Autographs.
Power Handling Capacity:
Free Air Resonance (FS):
Price When Launched:
Equivalent Present Day Price:
Current UK Price:
£1,300 to £1,800*
pair of drivers & crossovers.
Look & Feel
These drivers, 46 years after they were made, still look very
impressive. The baskets are made from a very
rigid die cast alloy and are stove enamelled. Diaphragms are made form paper.
Interestingly, the diaphragm suspension is an extension of the
actual diaphragm (paper) and it is coated with rubbery looking
substance, presumably to aid with cone termination and to tune
resonance frequency to the desired level. The throat of the horn
is made from untreated metal, which when mixed with humid
British weather, often results in minor oxidation on the throat
surface. The motors are rather large alnico magnets hidden under
gold plastic covers. The crossovers are nicely soldered,
using components available at the time when these were made. Wires and plugs
are rather low quality by modern standards, however, they were
probably ok back in the day. Overall, despite the pitfalls,
really impressive drivers. Playing with these drivers was like
playing with an old Jaguar E Type - classic beauty. Photos
below present the drivers and crossovers after the
When plugged in for the first time they were very
overwhelming - in a good way though. The presentation of the
sound is very different than in the traditional speaker
constructions. First thing that I noticed was the soundstage. It
was like a massive wall of sound, quoting Troels Gravesen, it
sounded like "giant pair of earphones". The soundstage was
still there, and I was able to separate the instruments, etc.,
but the sound was never coming from 10 meters behind the
speakers, so not much soundstage depth.
The speakers are also
very fast and dynamic. And when compared with modern speakers,
this can be very nice. Feeling the physical impact of the sound
is not something that people are used to these days, especially
people who use stand mount monitors for playback. Bass is never
floppy or boomy and always stays under control. And it goes
deep, very deep. Even at 35Hz using signal generator you can
clearly hear the sound.
Midrange and treble sound very good indeed, being very sweet and
easy to listen. Saying this, the MG15s are not the most detailed
speakers in the world.
They are many more speakers that are more detailed and provide
better separation, but there are not many speakers that deliver
full bodied sweet sound that these Monitor Golds do. What they
do best is saxophones (I have never heard Ben Webster's My
Romance sounding so realistic on any other speakers), double
bass (Temptation by Diana Krall sounds mind bowing) and vocals,
although some of the higher sections may sound a bit edgy - like
Tears Behind My Eyes by Spooky Tooth. Where these speakers
struggle, is when depth of the soundstage and separation play
important role in the track - try Eric Bibb - Needed Time or
Chris Rea - Auberge. And don't get me wrong,
they will still sound fairly detailed and easy to listen, however,
they are other speaker within this price range that can deliver
much deeper soundstage imaging. They are also not the most
truthful presenters - there is a degree of sound colouration.
But, don't be put off by this as this is part of their character
and part of what makes them special. To me the most important factor
when listening is
enjoyment and engagement, and these drivers can
certainly deliver both.
Regarding amplification, many people (probably due to
sensitivity of these drivers) suggest using them with valve
amps. From what I have read, these drivers were designed with
transistor amps in mind, hence their 8 ohm nominal impedance.
I've tried them with both valve and transistor amps and I much
prefer their sound with good transistor, mainly due to better
dynamics and bass control.
Very musical and easy to listen. No the most detailed, and
the soundstage depth is far from ideal, but despite these
pitfalls, still very enjoyable. Overall, sweet sound, with a lot
of kick and energy to it.
Balance of Sound:
Neutrality of Tone:
Please note - if you want to know what I
mean be the descriptions above, hover you mouse over them.
More detailed information will be available in separate
section of this website.