AER Diaphragms (BD-Design)

by GC, Sunday, April 10, 2005, 22:11 (4670 days ago)

Any comments or opinions on the suitability of the AER replacement diaphragms for PM2A's that are front loaded 130Hz Tractrix and rear loaded 35Hz Bass Horn?

Is there any loss of efficiency by using such an alternative diaphragm?

Ta

Mark

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AER Diaphragms

by GC, Sunday, April 10, 2005, 23:24 (4669 days ago) @ GC

Hi Mark,

Sorry for editing your post but this way the information is more accurate.

The diagrams you were referring to are the same as AER replacement diaphragms, the source you pointed to is "fake" and therefore they don't deserve any attention through this board...

Any comments or opinions on the suitability of the AER replacement
diaphragms for PM2A's that are front loaded 130Hz Tractrix and rear loaded
35Hz Bass Horn?

Is there any loss of efficiency by using such an alternative diaphragm?

There is loss in output due to the higher impedance (less current flowing) and due to the shorter coil. The advantages are bigger though, more linear excursion, real extention into the highest frequencies and a more natural tonal balance. You will probably get more warmth in the bass also due to the higher Q of the driver system.

I used these replacement diaphragms on PM4A's as reference for a long time until AER made better magnets than those...

Ciao,

Bert

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AER Diaphragms

by GC, Monday, April 11, 2005, 18:15 (4669 days ago) @ GC

Hi Mark,

Sorry for editing your post but this way the information is more
accurate.

The diagrams you were referring to are the same as AER replacement
diaphragms, the source you pointed to is "fake" and therefore they don't
deserve any attention through this board...

Any comments or opinions on the suitability of the AER replacement
diaphragms for PM2A's that are front loaded 130Hz Tractrix and rear

loaded

35Hz Bass Horn?

Is there any loss of efficiency by using such an alternative diaphragm?


There is loss in output due to the higher impedance (less current flowing)
and due to the shorter coil. The advantages are bigger though, more linear
excursion, real extention into the highest frequencies and a more natural
tonal balance. You will probably get more warmth in the bass also due to
the higher Q of the driver system.

I used these replacement diaphragms on PM4A's as reference for a long time
until AER made better magnets than those...

Ciao,

Bert

Hello Bert,

Fake? not quite with you on that but if it is a fake site then it is possible to have them closed down.

I have 4A's as well as 2A' but I prefer 2A's in my system.

Some wee pics

[image]

[image]

Ciao

Mark

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AER Diaphragms

by GC, Tuesday, April 12, 2005, 00:17 (4668 days ago) @ GC

Hi Mark,

Fake? not quite with you on that but if it is a fake site then it is
possible to have them closed down.

That is not that easy to do when the owner of that domain does not want to coƶperate and keeps bothering people...

Some wee pics

These are old pics! Why did I not see these before? Nice looking though... :)

Ciao,

Bert

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AER Diaphragms

by GC, Tuesday, April 12, 2005, 08:31 (4668 days ago) @ GC
edited by GC, Tuesday, April 12, 2005, 08:39

Hi Mark,

Fake? not quite with you on that but if it is a fake site then it is
possible to have them closed down.


That is not that easy to do when the owner of that domain does not want to
coƶperate and keeps bothering people...

Some wee pics


These are old pics! Why did I not see these before? Nice looking though...
:)


Ciao,

Bert

Yes Bert I finally binned the aging 150Hz Prototype Tractrix square horns and built these polygonal units with a slightly lower Fc.

A new matching bass horn is in progress to replace the prototype bass horns seen here.

So very slowly getting there (over years lol)

Some addnl pics:

[image]

[image]


Best

Mark

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AER Diaphragms

by GC, France, Tuesday, April 12, 2005, 13:02 (4668 days ago) @ GC

Hi Mark,

I have a pair of PM4As with the AER diapraghms in my Oris 150's back in New Zealand that sound fantastic being powered by a 45 SET that uses a pair of your Old Brown Dog output transformers. I'm missing them very much while I am living in France for work, but a good friend who is looking after them does not seem to be complaining ;-)

Hope all is well with you. Are you still making the transformers? I promised I'd send you a photo of the amp. I'll post a photo here.

Regards,

Russell

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AER Diaphragms

by GC, Tuesday, April 12, 2005, 13:40 (4668 days ago) @ GC

Hi Mark,

I have a pair of PM4As with the AER diapraghms in my Oris 150's back in
New Zealand that sound fantastic being powered by a 45 SET that uses a
pair of your Old Brown Dog output transformers. I'm missing them very much
while I am living in France for work, but a good friend who is looking
after them does not seem to be complaining ;-)

Hope all is well with you. Are you still making the transformers? I
promised I'd send you a photo of the amp. I'll post a photo here.

Regards,

Russell

Hi Russell yes I still wind OPT's but not very often - enough to satisfy my own needs! But OBD is still alive and well!

Well I never got to make the OBD logos for your T-Shirt either! ;)

I need to look into these new diaphragms but I am doing some experiments at the moment as I have a fare number of standard Lowther spares for my 2A/4A's as well as a pair of the new Lowther reverse roll diaphs which I don't like.

Essentially I am trying out a reverse roll on a standard whizzer - I'll post some pics one of these days!

The new Lowther reverse roll diaph has a 5mm reverse lip made out of the standard whizzer template which means the whizzer is now effectively 5mm shorter.

What I have done this weekend is add on a 5mm reverse lip on a standard whizzer cone - we shall see....

If that does not cure the remaining "Lowther Shout" then I will be up for a pair of AER's

Best

Mark

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AER Diaphragms

by GC, Tuesday, April 12, 2005, 19:36 (4668 days ago) @ GC

Hi Russell yes I still wind OPT's but not very often - enough to satisfy
my own needs! But OBD is still alive and well!

So I should treasure my pair! I've always been really impressed with them.


Well I never got to make the OBD logos for your T-Shirt either! ;)

I'm still keen to waer that T-shirt


I need to look into these new diaphragms but I am doing some experiments
at the moment as I have a fare number of standard Lowther spares for my
2A/4A's as well as a pair of the new Lowther reverse roll diaphs which I
don't like.

I've not heard the new Lowther cones.

Essentially I am trying out a reverse roll on a standard whizzer - I'll
post some pics one of these days!

The new Lowther reverse roll diaph has a 5mm reverse lip made out of the
standard whizzer template which means the whizzer is now effectively 5mm
shorter.

What I have done this weekend is add on a 5mm reverse lip on a standard
whizzer cone - we shall see....

I'm sure lots of people are interested in your experiment.


If that does not cure the remaining "Lowther Shout" then I will be up for
a pair of AER's

You won't be disappointed if you do.

I've sent Bert a couple of photos of my amp which he might post here. It's called the Little Red Rooster - a 5842 IT coupled to a 45. Works really well.

Nice to correspond with you.

Cheers,

Russell


Best

Mark

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Pictures

by GC, Wednesday, April 13, 2005, 08:50 (4667 days ago) @ GC

[image]

[image]

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Pictures

by GC, Wednesday, April 13, 2005, 16:31 (4667 days ago) @ GC

Looking really good there Russell - IT's from Sowter I assume?

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Pictures

by GC, Thursday, April 14, 2005, 20:36 (4666 days ago) @ GC

Looking really good there Russell - IT's from Sowter I assume?

No - far to mainstream ;-) They were wound by a guy in Wellington NZ. The amp weighs a ton - it has a petty large power supply transformer and two PS chokes.

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Pictures

by GC, Thursday, April 14, 2005, 21:11 (4666 days ago) @ GC
edited by GC, Thursday, April 14, 2005, 21:21

Looking really good there Russell - IT's from Sowter I assume?


No - far to mainstream ;-) They were wound by a guy in Wellington NZ. The
amp weighs a ton - it has a petty large power supply transformer and two
PS chokes.


Aha now you are talking - all custom wound iron - has to sound good ;-)

I started prototyping IT's and input trans (mu metal lams) for an all iron amp but it has never got further than that....if only there was more time...

Currently finalising my bass horn - finally I will get a horn in that will be painted and finished.

Some pics of my amp:

[image]

[image]


and something else that I have made in recent years wax caps:

[image]

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Pictures

by GC, Sunday, April 17, 2005, 10:48 (4663 days ago) @ GC

Nice looking amps, and those caps look intriguing.

Looking really good there Russell - IT's from Sowter I assume?


No - far to mainstream ;-) They were wound by a guy in Wellington NZ.

The

amp weighs a ton - it has a petty large power supply transformer and

two

PS chokes.

Aha now you are talking - all custom wound iron - has to sound good ;-)

I started prototyping IT's and input trans (mu metal lams) for an all iron
amp but it has never got further than that....if only there was more
time...

Currently finalising my bass horn - finally I will get a horn in that will
be painted and finished.

Some pics of my amp:

[image]

[image]


and something else that I have made in recent years wax caps:

[image]

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