View Single Post
  #3 (permalink)  
Old December 24th 04, 01:00 PM posted to uk.rec.audio
Jim Lesurf
external usenet poster
 
Posts: 3,051
Default Magneplanar 1.6 QR speakers

In article , dersu wrote:
Anyone got them? I auditioned a pair today - I hadn't got my own choice
of CDs with me and the selection of classical music in the shop was
poor. However I was impressed. Are they as good as I thought they
sounded at first hearing? If I buy them they will be replacing Rogers
LS3/5a's and LS1 subwoofer in a larger listening room. My amp, which I
do not want to change, is a Quad 34/405 recently overhauled and
performing "as new." Will this be sufficient? Any other comments will be
appreciated.


I would be cautious of assuming the 405 would be an appropriate power amp
for the Magneplanar speakers.

IIRC Magneplanar speakers have a general reputation for having low
impedances. I've just looked at some reviews of the 1.6QR and they seem to
report that it has a 'typical' resistance of 4 Ohms.

You do not say what version of the 405 you have, nor if the overhaul has
actually brought it up to the performance of 'late' versions, or to its
orginal state. However the early version of the 405 had quite 'strict'
current limiting.

The (potential) problem is that if the amp can only supply the order of 5
Amps, then that will only give about 20V across a 4 Ohm load. i.e. about
half what the 405 can supply into higher impedance loads. The amp can
probably do better than 5 Amps, but you may find the peak levels you can
get are current limited.

If you only listen at modest or low sound levels and are not in a large
room, the above may not matter at all as you may not be wishing to produce
high levels, and hence any current limitations of the 405 may not matter in
your case.

You are unlikely to get this problem with LS3/5A's as they have a
relatively high impedance in most of their incarnations. :-)

What amp did the shop use when demo-ing the Magneplanar speakers?

As with Electrostatics, the Magneplanars tend to interact with the room
acoustic in a different way to conventional 'cone-and-box' speakers. Hence
this is something else you may need to consider.

Thus the suitability may depend on your taste in music, the levels you like
to listen to, and the listening room. Hence it is hard to be more specific
in answering your questions without more info.

Will the shop either let you try the speakers before you buy, and/or
perhaps let you take the 34/405 into the shop and use them there to drive
the speakers?

FWIW I personally prefer 'panel' speakers - in my case the Quad ESL's - to
conventional types. Hence I am not trying to discourage you from choosing
the Magneplanar speakers. But I would be wary of using a 405 to drive them.

Slainte,

Jim

--
Electronics http://www.st-and.ac.uk/~www_pa/Scot...o/electron.htm
Audio Misc http://www.st-and.demon.co.uk/AudioMisc/index.html
Armstrong Audio http://www.st-and.demon.co.uk/Audio/armstrong.html
Barbirolli Soc. http://www.st-and.demon.co.uk/JBSoc/JBSoc.html