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Ringmat
Concept Loudspeakers
For many years
Ringmat and QR Design have been using for their research a ‘Ringmat
modified’ version of Max Townshend’s ‘Sir Tristian’ Loudspeakers,
which were made when Max was manufacturing in Malta. They were the
only pair to be brought to the UK and have proved to be an excellent
tool for our design work.
Since those early
days, our understanding of the ingredients for accurate sound
reproduction has increased immeasurably and it is now desirable for
a wider audience to be acquainted with the fruits of our research
work. This will entail demonstrations of the advances we have made
and will show the direction in which the industry needs to move in
order to achieve a decisively more accurate sound reproduction in
the future. Not only of the audio equipment itself that is required
for accurate sound reproduction but also, and perhaps more
importantly, of the standards required in future for the software –
the records, CDs and DVDs. At the moment, the systems of
reproduction used everywhere and the software available for sale to
the public all contain a tremendous amount of avoidable corruption.
A big education
programme is required.
As a first stage in
our plan, we have taken delivery (August 2007) of a pair of
loudspeakers built for us by Auracoustic to our specification [http://www.auracoustic.co.uk].
These Ringmat speakers are unusual in that they embody many features
not found in other loudspeakers - they are speakers of the future in
terms of concepts, as opposed to any defined article. We therefore
refer to them as our ’Concept’ loudspeakers, in much the same way as
car manufacturers design ‘concept’ cars. This does not mean they
cannot be made available as custom-built orders, and we are already
receiving enquiries about them from people who have been aware of
our plans.
The significant
features are as follows:
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There is no crossover, there are
no capacitors or inductors, so no corruption of the absolute phase
of the signal
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The drive units are orientated in
a particular way to obtain maximum accuracy in imaging to our own
formula, with the right hand speaker being a mirror image of the
left hand speaker rather than identical; ideally, they need to be
driven by mono block power amplifiers fed separately from the
mains (i.e. each has its own mains lead); not for reasons of
‘power’, but so that the mains delivery to each power amplifier
can be separate, as the mains power to one power amplifier needs
to be inverted to that of the other; the ‘mirror image’ aspect is
purely to get imaging accurately reproduced because of the way the
signal is fed to the drive units in the particular configuration
we will specify for the amplifier and mains lead connections in
order to overcome a major aspect of corruption in commercial
software
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The drive units are accurately
time-aligned and in line perpendicularly down the centre of the
cabinets
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The cabinets are made of
substantially braced plywood
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We have opted for a special
textured paint finish (wood veneer is impractical for custom built
cabinets anyway); there is therefore a wide choice of colours
available
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The cabinets have been specially
lined with cork to our own specification, including internal use
of our cork domes – no foam, no wool, no carpet or any of the
usual stuff that damages sound reproduction obtained through other
loudspeakers
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Our own Pure Power speaker cable
has been used for internal wiring, the number of strands selected
as specified and connections crimped and bolted, not soldered
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The baskets of all the drive
units have been substantially earthed
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Ports are flared at each end
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There are no horn effects for the
drive units
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Although the cabinets are
substantial and very heavy, they can breathe
They are, of course,
designed to rest on large Ringmat Domes, each placed upon a set of 3
Ringmat Mammoth Feet. On top of each speaker is a Ringmat Cabinet
Damper.
Drive unit specifications
Each loudspeaker
has:
1 pair of Visaton
8ohm Ribbon Tweeters MHT12 (made in Germany) working in parallel
Efficiency/Sensitivity 91dB
Nominal
Frequency Range 2.5K – 40K
1 pair of 10” Volt
Studio 8ohm mid-bass drivers (made in UK) working in parallel
Efficiency/Sensitivity 92dB
Nominal
Frequency Range 32K – 2.5K
In view of the drive
unit arrangement, the speakers present a 2ohm load
16ohm drive units in
this arrangement would give a 4ohm load, but the Visaton Ribbons are
only available at the moment as 8ohm.
We initially
arranged the drive units in series rather than in parallel. This
gave us an overall 8ohm speaker instead of a 2ohm speaker, but we
have not had the opportunity to try them in this arrangement since
the final modifications were made to the internal lining and tuning
of the speakers. This was all done using the 2ohm load, with which
our modest 70w amplification has no problem at all.
One question in the
minds of some people might be the danger of using the ribbon
tweeters free range, as the conventional wisdom is that they would
overheat and thereby be damaged.
The way to protect the tweeters is
to use a small PTC (Positive
Temperature Co-efficient) resistor connected in series to the
tweeters called a polyswitch. If the current exceeds a certain
level, the resistance rises and at the appropriate point the current
is switched to protect the drive units. It is important to use the
correct value of the polyswitch, which value has been provided to us
by Visaton.
Another concern
might be the presence of bass response in the speakers, or lack of
it, due to the absence of a crossover. There is no lack of bass in
the concept speakers; indeed, the challenge is to position the
speakers within the listening room so that the listener is not
overwhelmed with bass, and that the clarity of the recording is
still retained despite the massive, deep bass response.
It hardly behoves us
to talk about the performance of these ‘concept’ speakers, other
than perhaps to say that in all his years of experience John Rogers
has never heard such an awesome and, at the same time, such a
musical and accurate reproduction from a pair of loudspeakers. It
is this combination of power and detailed, even delicate, accuracy
that is so special, that feeling that one is actually sitting there
at the time of the recording facing artists playing and singing,
talking even, which can be particularly difficult to reproduce
realistically.
© Copyright 2007
Ringmat Developments
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