Low-pass filter thoughts
 

On Thu, 21 Oct 2004 19:33:58 +0100, "Wally"
wrote:

Stewart Pinkerton wrote:

If it's good enough for Meridian output stages, then it's good enough
for me! :-)

They're in the 203? That means that my audio signal goes through nothing but
5534s before hitting the valves (which are soaked in swamp water to give 'em
soul...).

They are indeed in the 203. Ditch the valves and you'll have some
chance of hearing what the performer intended (it's not all soul
music, y'know!)........................
--

Stewart Pinkerton | Music is Art - Audio is Engineering

Low-pass filter thoughts
 

In article , Stewart Pinkerton
wrote:
On Thu, 21 Oct 2004 19:33:58 +0100, "Wally"
wrote:

Stewart Pinkerton wrote:

If it's good enough for Meridian output stages, then it's good enough
for me! :-)

They're in the 203? That means that my audio signal goes through
nothing but 5534s before hitting the valves (which are soaked in swamp
water to give 'em soul...).

They are indeed in the 203. Ditch the valves and you'll have some chance
of hearing what the performer intended (it's not all soul music,
y'know!)........................

If you/anyone has available circuit diagrams for the 200/203/263 I would
love to have a copy. :-)

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

Low-pass filter thoughts
 

Eiron wrote:
Wally wrote:

Eiron wrote:


You really are better off with steep high and low pass filters.
Trying to match the hf response of a sub to the lf response of a
mid-range box is difficult, and putting a lot of power through the
mid-range below its resonant frequency is asking for trouble.



The 'midrange' is a KEF B110, which I believe has a sufficiently low
resonant frequency to serve as a bass driver as well.


I'm listening to one at the moment.
I like them but Stuart P thinks that the sound from a Bextrene cone
collapses at low levels.

Here are some specs for a typical box using the B110:
http://www.mhennessy.f9.co.uk/rogers/ls35a_page4.jpg

If you use an open baffle or reflex box then the cone will flap about
dangerously at moderate power levels (without a high-pass filter)
You should be OK with a closed box and up to a 100w amp
but I would still recommend a 2-way 4th-order Linkwitz-Riley crossover
at 100hz or higher.


Very good active crossovers can be obtained from Marchand Electronics.
Fully assembled variable crossover frequency (XM9) = $700. Single
crossover frequency kit (XM1)= $100

No connection. just a happy customer

N

Low-pass filter thoughts
 

On Thu, 21 Oct 2004 00:03:27 +0100, Eiron wrote:

Wally wrote:

Eiron wrote:


You really are better off with steep high and low pass filters.
Trying to match the hf response of a sub to the lf response of a
mid-range box is difficult, and putting a lot of power through the
mid-range below its resonant frequency is asking for trouble.


The 'midrange' is a KEF B110, which I believe has a sufficiently low
resonant frequency to serve as a bass driver as well.

I'm listening to one at the moment.
I like them but Stuart P thinks that the sound from a Bextrene cone
collapses at low levels.

Here are some specs for a typical box using the B110:
http://www.mhennessy.f9.co.uk/rogers/ls35a_page4.jpg

If you use an open baffle or reflex box then the cone will flap about
dangerously at moderate power levels (without a high-pass filter)
You should be OK with a closed box and up to a 100w amp
but I would still recommend a 2-way 4th-order Linkwitz-Riley crossover
at 100hz or higher.

The B110 should always be used in a small enclosure of less than ten
litres - and yes, the low-level detail does collapse as you wind down
the volume. That's why no one uses Bextrene any more.
--

Stewart Pinkerton | Music is Art - Audio is Engineering

Low-pass filter thoughts
 

Jim Lesurf wrote:

Scots Guide? One of your pages?

Erm... Hundreds, actually. ;-)

Have a look at the 'Scots Guide' address in my sig, below. When
there, go to the section on 'Analog and Audio', and you will then
find a link to some pages on active filters. There are bits on
related topics scattered around the 'Guide'.

Thanks, Jim. I'll have a look over the next few days - I've got a borrowed
scope coming after ther weekend (my own has packed in - one trace down, and
nil timebase - can't do much with a vertical line!), so I'll be wanting to
make a start with the breadboard by then.


--
Wally
www.artbywally.com
www.wally.myby.co.uk

Low-pass filter thoughts
 

Dave Plowman (News) wrote:

I haven't looked for them yet - found a Phillips data sheet that
said hey were discontinued, so assumed they might be hard to find.

Could be that refers to an 'N' suffix.

I've sourced some 5532s with an A-something(P?) suffix, which apparently
means they have a guaranteed noise spec.


--
Wally
www.artbywally.com
www.wally.myby.co.uk