In message , Don Pearce
writes
On Tue, 24 Oct 2006 23:48:43 +0100, Kevin Seal wrote:

In message , Don Pearce
writes
On Tue, 24 Oct 2006 18:52:21 +0100, Kevin Seal wrote:

In message , Don Pearce
writes
On Mon, 23 Oct 2006 23:05:05 +0100, Kevin Seal wrote:

In message , Don Pearce
writes
On Mon, 23 Oct 2006 19:03:29 +0100, Kevin Seal wrote:

As I said, I am not saying these show the response of the cartridge,
which has many mechanical factors affecting it. What my posts show is
the way the response *changes* with capacitive loading. There could be
all sorts of lumps, bumps and sags in the actual response, but that is
not what I'm dealing with.

But if your maths do not show what real world tests produce, surely
something is missing from the equation?
--

Sorry, Kevin, I'm not explaining this again. If you haven't understood
by now I have to give up.

I understand perfectly what you are saying. But what you won't accept is
that your maths do not show the truth, the V15V was less affected by
capacitance loading than the V15III.

The V15III requires double the load capacitance of the V15V so a given
change in total absolute capacitance will constitute only half the
percentage change in relative capacitance. There will therefore be
less variation as a result.

That's easy for you to say!


That is reflected in my results, but is
not the point I am making.

Having looked at your graphs again, I see that they are in fact totally
wrong.
Increased capacitance will actually *decrease* the HF response.
Hence why people found the V15III bright and harsh, because they had not
applied the correct capacitance load.

My graphs are wrong? They derive from my maths, which is shown as
well. If that is wrong, please show me the error - I'm always eager to
learn. If you are saying that while my calculations are correct, the
result is wrong, then I will have to ask you where Shure got
permission to abdicate from the real physical world.

What I am saying is, if you run a frequency reponse test using the gear
I mentioned in a previous post, and load the V15III with 250pF, the HF
will peak.
If you then increase the load to 450pF, the HF will flatten out.
This is the total opposite of what your graphs show.

Show me.

Well there you have me, I don't work for Shure any more, and I didn't
think I would ever have the need to keep the B & K pen recorder traces!!

History is on my side though, as all the Hi Fi mags of the day
complained about the bright top end of the V15III. After we pointed out
to them about the loading, it got much better reviews.

--
Kevin Seal
F800ST
{kevin at the hyphen seal hyphen house dot freeserve dot co dot uk}