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AR925E


djcheung

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Hi all,

Recently purchased a pair of AR925E.

All drivers are original but with torn grill sock.

Managed to clean the old foam surround off and put some BLO on the top piece of wood.

Still waiting for the new foam surround to arrive.

Before that, I wonder if anybody here have heard them and what kind of things should I watch out for.

I have AR94's and since they are of similar sized cabinets, should they sound similar?

I haven't looked at the xover board yet.

I have checked all drivers and they measure roughly between 3-4 ohms.

Best regards,

David.

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Nice project. I'm not familiar with that model but here's how I dealt with the socks on my 94s: http://www.classicspeakerpages.net/IP.Board/index.php?showtopic=8149

Or if you're handy with a sewing machine (I'm not) you could make new socks to match your 94s.

Keep us posted

-Kent

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Hi Kent,

Thanks very much for your inspirations.

I was thinking between getting new cloth and make new grills, but now I will definitely get rid of the socks

I can use the old cloth ( the good parts ) to make the grills.

I will keep the terminals to the bottom of the speakers.

The XO is slightly different to the 94's - I will post some pictures.

I have started filling in the rough surfaces on the cabinets ( really rough chipboard end cuts ) with wood fillers.

Then I will probably finish it with matt black.

The top piece of wood is off the cabinets and having a few coats of BLO but may end up with a few coats of polyurethane.

In that case I may finish the cabinets in glossy black. :D

That will be a few weeks away !

Best regards,

David.

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  • 1 month later...

Just a quick update on the 925e.

The sock is beyond repair !

I have removed it completely and going to put a new grill on.

I have painted the outside.

Still waiting to get the grill made.

Does anybody has the crossover schematic for it?

I have been trying to trace the wiring but it is more complicated to draw on paper.

I am not experience with crossover designs.

Can anybody help ?

Have a very nice Christmas.

David.

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Just a quick update on the 925e.

The sock is beyond repair !

I have removed it completely and going to put a new grill on.

I have painted the outside.

Still waiting to get the grill made.

Does anybody has the crossover schematic for it?

I have been trying to trace the wiring but it is more complicated to draw on paper.

I am not experience with crossover designs.

Can anybody help ?

Have a very nice Christmas.

David.

David,

Other than the cabinet "sock" there is little in common between the AR-94 and the 925e, which appears to be essentially the same as the AR-92...with a sock. There may be some information for this model here:

http://www.classicspeakerpages.net/library/acoustic_research/special_sections/ar_drawings.html

Is there a particular reason you want the schematic, or are you just curious? The cap values are clearly marked in your photo. It is obviously more complex than that of the AR-94.

Roy

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Hi Roy,

Thanks very much for the link but unfortunately there is no crossover schematics for the 925e.

I have traced out the circuit rougly.

I am just curious about the connection on the tweeter and wonder if it is correct.

David.

David,

I'm fairly certain the yellow wire connects to the + side of the tweeter as shown in your drawing. It would be very unusual for that not to be the case.

Roy

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Thanks Roy,

I will change the 4uf and 8uf to see if the midrange and tweeter will improve. They sound ok but a bit quiet.

Are the 24uf and 80uf for the woofer section?

Do you think they are worth changing?

I am not too good at crossovers.

I am only what they called a garage technician ( parts swapper :D ) here in the UK.

I don't have any measuring equipment apart from a basic multimeter.

Best regards,

David.

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Thanks Roy,

I will change the 4uf and 8uf to see if the midrange and tweeter will improve. They sound ok but a bit quiet.

Are the 24uf and 80uf for the woofer section?

Do you think they are worth changing?

I am not too good at crossovers.

I am only what they called a garage technician ( parts swapper :D ) here in the UK.

I don't have any measuring equipment apart from a basic multimeter.

Best regards,

David.

It can't hurt to replace caps, but the odds are against it making a big difference. The 24uf cap is in series with the mid and the 80uf cap is in parallel with the woofer.

Imo, the problem with this speaker is the same as that of the AR-58 era...no level controls. Similar predecessors, such as the AR-5, AR-12, and AR-92, all had level controls or switches for the tweeters and mids.

Roy

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Thanks Roy,

I have replaced the 4uf & 8uf with the Solen from the left over of another project.

Not too sure what type of capacitors I should get for the 24uf and 80uf.

There isn't much space on the xcover board so they will need to be close to the original caps sizes.

The verdict on the new 4uf and 8uf.

The upper ranges seem clearer and with higher output.

I think I will need to run them in a little longer.

Best regards,

David.

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Thanks Roy,

I have replaced the 4uf & 8uf with the Solen from the left over of another project.

Not too sure what type of capacitors I should get for the 24uf and 80uf.

There isn't much space on the xcover board so they will need to be close to the original caps sizes.

The verdict on the new 4uf and 8uf.

The upper ranges seem clearer and with higher output.

I think I will need to run them in a little longer.

Best regards,

David.

David,

Hopefully you will become used to the sound. The new caps are not going to change to any appreciable degree.

If you intend to replace the remaining capacitors, non-polar electrolytic caps (npe's) are small enough to fit on the board. Alternatively, you can run wires from the board and mount larger film caps elsewhere in the cabinet.

Roy

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Based on the hand written drawing the tweeter appears to be wired out of phase.

Perhaps this is what was confusing to the OP.

I don't know the reason behind doing this but my son's TSW610s have the mid and tweeter wired out of phase and this agrees with the factory schematic drawing.

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Thanks DavidR,

I was just wondering although the connection cables at the speaker end are correct but the polarity at the other end are reversed.

Don't know the reason for connecting the tweeter 'out of phase'.

But at least now I know that it is part of the design.

The new caps are opening up a bit but at the same time they are sounding a bit harsh to my aging ears.

Some of the music instrument details are getting clearer but at the same time making me to turn the volumn down due to harshness.

At the moment they sounds a bit thin. I think because they are designed to be placed against the back wall but I have placed them in the middle of the room for testing.

My speaker collection has gone a bit mad and I physically can't find a free piece of wall. :D

Best regards,

David.

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Unfortunately I have a number of other AR speakers that do not sound as harsh as them.

Not too sure my ears can listen to them long enough to adjust to them!

Even the recapped AR9 sound warmer than them.

But then again they cannot be compared.

I Would let the caps run in for a little while.

May use them for the surround with the AR94 as front and AR4C as center.

Have a Happy New Year.

David.

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I'm hoping one of the technical members can tell us why drivers are sometimes wired out-of-phase.

Anyone?

David,

It is a very common part of crossover design having to do with phase shifting and smoothing of frequency response at crossover points between drivers.

Roy

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