View Single Post
  #6   Report Post  
Posted to rec.audio.pro
leutholl
 
Posts: n/a
Default What would you do with Philips 22AH587

Am 1 Mar 2006 05:46:40 -0800 schrieb Mike Rivers:

leutholl wrote:

For those who know the Philips 22AH587/00R studio speakers:
How would you use them?


I don't know model numbers, but I recall some Phillips powered speakers
that got some good use in portable recording back in the early 1990s.
The ones I remember were two-way, about the size of Tannoy Reveals,
about right to set up in a van for a temporary remote rig.

The Philips are very old but are triamped. The Bass speaker is MFB (Motion
Feedback) I guess they have some sort of a piezo or coil to messure the
membrane movement, this will be feedbacked to the preamp to enhance the
impuls response - I guess!


There's an extra winding on the voice coil for motion feedback. It
seemed to work pretty well given that the amplifier was designed to
work specifically for those speakers.

1. I guess the controls on the back are not calibrated anymore - They look
very diffrent for both speakers and it's not easy for me to adjust this for
linearity.


There could be something deteriorated in the drivers or electronics.
What do you mean by "adjust this for linearity?" I expect that there
are level controls as well as high frequency level. Is there also some
sort of equalizer in there? Can you bypass it?

2. One midrange speaker was brocken (the connection wire to the coil was
burned), I openend the midrange speaker, took one winding of the coil to
have a new connection, soldered it to the cable and now it is working. But
I heard, that as soon you disassemble a speaker, pull the coil out of the
magnet, the speaker is ill. The speaker has a huge magnet and over this
magnet there was a plastic cup. This cup is broken now, and I think the
midrange speaker recieves too much air from the bass speaker.


That sounds broken to me. But not seriously broken. I don't understand
just what you disassembled, but if you got it all back together without
having the voice coil rub on the magnet assembly and have it working
electrically, you can always fix the cover over the back of the
speaker.

Do you know the Philips? How do you like them? What would you recommend to
me how to use these speakers?


How badly do you want to use them? Obviously they need to be fixed up
in order to be used for anything that requires any sort of accuracy,
but if they're working right they would probably make pretty decent
monitors, or at least good listening speakers. How big are they? If
they're large, do you have room to place them correctly in your room?

Do you recommend me not to use the speaker due to the fact that they are
not adjusted (can I do this - how?) and/or the fact that one midrange
speaker is handicaped.


You can certainly use them for listening to the radio. But you should
figure out the adjustments, and figure out what's working and what's
not. I know you're hoping that someone will jump in who has exactly the
same speaker that you have, but given that this is an old unit that was
never very popular as a studio tool, this isn't very likely. You might
do better asking in a not-too-hi-end audiophile newsgroup. That's where
you're more likely to find someone who has, or has had those speakers.

all-in-all, what would you do with them?


Frankly, if I didn't need them (which I don't) I'd sell them as-is. Or
more realistically, put them in my garage on the continually growing
pile of stuff that doesn't work any more, that I don't need any more,
that nobody else needs either, but was too expensive to just throw
away.


Thanks a lot, Mike!

I don't use them for now for these reasons, but I think they are a sort of
a mixture between studio monitors and hifi-speakers.

With "adjust this for linearity?" I mean to set the level controls of each
integrated amp (3) and the feedback gain of the MFB cirucit in order to
have the box as linear as possible. Do you do this by ears or with a RTA or
both? The room is optimized but not perfect!
While I can do this for the level control what to do with the MFB?
as i turn the MFB control up, I see that the membran will be much tigther
(like tuning drums) and the bass it tighter but with less volume.

The plastic cup or cover if you want, serves to save the middle speaker
from air coming from the bass speaker. This air will blow inside the box
and if you don't install this cap, the air can get out THROUGH the middle
speaker. This cap is now broken and I can't install this having every
single gap air-proofed.

The size is something between a GENELEC 1030 and 1037, so medium size.
What do you suggest me to watch out when installing big monitors in a small
room? I have enough distance to the back wall and side wall.

Maybe I will sell them as a handicraft goodie on ebay....

Thanks a lot,

Lukas