Thanks for your interest.
I have sent my cheque and await the materials arrival,it should be with me in a couple of weeks.
This should be interesting as it is 18microns of copper on 12microns of polymide,this is the thinest I can obtain in small quanties of the shelf.
Other options have been 12 copper on 12 polymide and 5 copper
on 25 polymide but these have to be bought by the roll at
£6000 a roll OUCH!!
My present material is 18copper on 25 polymide so the mass reduction is worthwile.
There are so many possible design approaches with these planars
that I would like to try but with cost/time restraints I am having
to jump in a particular direction and hope any problems are not
fundemental to the chosen design.
I have found someone who can laser cut the steel pole piece profiles out for me [and other potential flat pieces] so this will
help with man hours for the next stage; making several pairs of phones for doing comparison work.
I am considering moulding the magnets/pole pieces into an integral whole using a filled epoxy for the transducer frame/body.
With pre cut metal parts layed into a mould and cast as one with
threaded inserts for fixtures, this should make producing the transducers a bit less painfull to make.
Properly designed ear pads and head band are in consideration also.
I am now investigating an amp design to partner it but this is
at very early stages,that said it is ever more urgent that I have
a very good amp for testing these things[not forgetting test equipment proper]
I have listened to the current phones for many hours now.
It is strange, put a sine wave sweep through them and they are
far [very] from perfect but boy they are nice to listen to with music.
It is always difficult to describe the sound of something but I would say they sounded thus:
A very powerfull bass with a stonking mid bass with the punch and torque continuing down to 40HZ[ish maybe a bit lower] then
rolling of relatively fast below that in power terms.
The punch and energy continue in the mids giving a fruity forward
sound marred by some uneveness caused by too much damping
at the ribbon ends[I feel 90% of this can be sorted in the next version]
Treble is smooth and natural but because of the hot mid and bass components can sound a tad dark.
The soundstage could be bigger though but suppose that is the
penalty for the forward gutsy intimate sound.
I would like to keep some of the above characteristics but certainly want better ambient low bass and some more air in the
Reading the above I do not know what sort of sound will be pictured but I am comparing with a Stax 4040 system with an
Arcam CD23 as source.
As for music they sound ok with all styles.
At the moment I really have no Idea how far I can improve this
design I hope I can achieve a balance of colorations that sound
nice, as for graphs etc who knows,
Afterall this is an artists folly.