Russian paper diaphrams for Altec horns

[Nyjblbob]

Received my paper diaphragms from Russia yesterday. These are a winner in my opinion. I was able to apply less attenuation to the horn, which I'm happy about. I paid him on January 4th and received them yesterday, January 28th. Sorry about the dark picture.

So these are the 1" versions?
Curious as for the 288 ones, as No one else makes them

 

[MissionX]

I have the 288B's. 1.4" I think. Been too long since they've been separated.

Curious as for the 288 ones, as No one else makes them

That's the key! He builds with the screw on connectors if you request. The ring is a little different. It's squared off and not beveled. The screw holes are depressed also instead of the head sitting on top. It tightened down okay. One thing though, there is a tiny gap in a portion of the cover. Not on both. I couldn't tell if you it was always like that.

Great Plains makes replacements. They are spade connectors, though. I think they went up $20 from the last time I looked.

 

[elitopus]

How is the HF response with these diaphragms? Would you say they’re the same as the other phragms, more rolled off, etc?

So the diaphragm mounting ring (don’t know if it’s the correct word. Frame maybe?) hits the rear cover? Is one diaphragm slightly taller than the other, or maybe your gaskets are slightly different on the drivers. Is that some kind of rope gasket they used? Lol.

 

[MissionX]

The mounting ring is hitting the screw heads of the speaker terminals on the cover. I'll look around for screws with smaller heads. I guess the bevel makes it a non issue. If I had a new rope gasket it would probably suffice. I'm not too worried about it. I believe the 288C came with deeper covers. I've taken them apart a few times without poking a hole with my screwdriver and don't want to press my luck. I didn't do a side by side comparison of each. Below is new vs. old.

As for the HF response goes, they sound good to me and now I have a matched pair. I'm not an expert or audiophile or even someone with good ears so I can't really comment on the roll off. They aren't muddy.

 

[elitopus]

Awesome. Thanks for the feedback. I’ll definitely consider a pair of these for my 288 drivers. I’d like to get them up and running.

 

[Selmerdave]

How challenging is swapping out diaphragms?

 

[Nyjblbob]

How challenging is swapping out diaphragms?

Around 10 screws on each 288 driver.
The biggest issue is holding the screwdriver with 2 hands one to turn it
And the other holding the tip so that it and the screw, as well as the terminal ends don’t get drawn into the diaphragms by the powerful magnet

 

[Selmerdave]

Around 10 screws on each 288 driver.
The biggest issue is holding the screwdriver with 2 hands one to turn it
And the other holding the tip so that it and the screw, as well as the terminal ends don’t get drawn into the diaphragms by the powerful magnet

Thanks, did you do it on your 604s?

 

[Nyjblbob]

Yes and probably over 50 other drivers
Jbls and Altec’s

 

[MissionX]

You have to stay focused on making sure the screwdriver doesn't get drawn into the magnet. A lapse in concentration and ...dink. I cover the diaphragm with my hand and loosen the screws.

 

[bowtie427ss]

Craftsmen sells(or used to) a nice set of non-magnetic stainless screwdrivers for a lot less than the cost of a replacement diaphragm

 

[elitopus]

I accidentally stabbed a diaphragm once on a small format Altec driver. Luckily it was a cheap Chinese diaphragm.
I cover the phragm now similar to what’s shown above.

I have a plastic flathead screwdriver that was part of a TV repairmans tool kit. But it’s only good if the screws aren’t super tight.

 

[MissionX]

I bought DATS and a UMIK-1 and also have REW. I'd like to learn how to use it if you want me to run some tests.

 

[elitopus]

I’d be curious to see some test results of the original diaphragm you have versus the paper diaphragm.

 

[MissionX]

I’d be curious to see some test results of the original diaphragm you have versus the paper diaphragm.

I don't know what tests to run or what they mean. Over on the crossover thread, I posted a comparison of the speaker output with the Rane crossover using a ST70 and a Magnavox 8608 on the tweeters. The Maggie still needs to be refurbed. BTW I'm looking for a thread on that. Not a total transformation, just a refurb to bring it up to snuff.

 

[elitopus]

That second graph is interesting. It shows the paper phragm dips from around 6khz to 15khz and then starts to come back up. So it looks like the Altec diaphragm has better HF extension. But other than that they look very similar. That’s a DATS chart right?

It would be interesting to see the response of the drivers on your mulitcells using REW. That’s a program that I downloaded but have never actually used. I had to buy a cheap Windows laptop to get it, since I’m all Apple otherwise. I just need to get a mic.

I want to get DATS one of these days too. Seems like it would be useful with all the DIY driver swaps I do.

 

[MissionX]

The graph is from REW on a Macbook. That's the A5 speaker with a 515B and a multicell horn. Not sure how to do much with DATS except get some measurements to post with ebay ads. I have about 10 Bozak drivers I need to sell.

 

[elitopus]

I thought REW and DATS didn’t work with Apple?

 

[elitopus]

But yeah that shows how much I know about taking measurements. Lol.
I read up on it on the forum that has a REW section a while back, but have forgotten most of it by now.

 

[Nyjblbob]

While Dyna70’s have legendary mids, they are hardly recognized for strong Bass fundamentals.