Altec 902 and 416-8C - X-Over freq?

[bowtie427ss]

What?
The small format drivers all had the same throat size.

I once believed this too.

There are 7/8 inch throat horns that mate with these drivers as well.

Here's a 7/8 inch throat 902.

[Old Guy]

What?
You don't need loading caps.....felt in the rear cover is best. Loading caps were meant to limit over excursion......if you get it that loud in your home, your ears will bleed.

BTW, Dickenson says the 902-8a is the best sounding HF driver, and I agree.

Ron

100% agreed the loading caps are not needed at 1200.

At 800 maybe. I would be cautious

If you wanna take the driver down to 500, you better

1 Add loading caps
2 Derate the power

I know you are aware of all this, just some readers might not be.

As you said, the caps were used to limit excursion, which is not caused just by power.

The 902 may be the best from 1200 up.

Having heard it crossed lower, I disagree it is better than an 802 tangerine from 800 up, and at 500 no contest the 802 wins.

they are different, the 900 series bandwidth is shifted upward. Different is not always the best, it depends on other factors.

[gearfreak]

- users experiences with 1200/800/500 cycle crossovers using the 902 (with/without loading cap)...

Not suggesting over the M19 xover suggestions, and no knowledge of how they relate electrically, but if desiring selectable, in order to adjust to taste, you may want to research / purchase one of the N-1285 series...

e.g.

http://www.altecpro.com/pdfs/vintage...%20Network.pdf

[mah]

In the pic, above, could the 7/8ths inch exit hole have been produced by inserting a 1/16th inch thick sleeve into a normal 1 inch exit hole?
If so, could the sleeve be readily removed?

[RonSSS]

Not suggesting over the M19 xover suggestions, and no knowledge of how they relate electrically, but if desiring selectable, in order to adjust to taste, you may want to research / purchase one of the N-1285 series...

e.g.

http://www.altecpro.com/pdfs/vintage...%20Network.pdf

I think this is an excellent idea.

Ron

[RonSSS]

In the pic, above, could the 7/8ths inch exit hole have been produced by inserting a 1/16th inch thick sleeve into a normal 1 inch exit hole?
If so, could the sleeve be readily removed?

I only have a guess here, but the 900 series drivers have a much shorter throat, so perhaps when mated to an earlier horn, the reduced diameter makes a better match. Just a thought.
I don't think you would want to remove the sleeve.

As far as lower crossover freq and over excursion, I would not think this to be an issue in domestic applications using low power. I can blow my ears out with 10w total to a pair of A7's in my living room, I never cared for the 500hz crossover anyway.

Ron

[bowtie427ss]

In the pic, above, could the 7/8ths inch exit hole have been produced by inserting a 1/16th inch thick sleeve into a normal 1 inch exit hole?
If so, could the sleeve be readily removed?

I have one of these with a loose tangerine, when time allows i'll dig into it and try to get a couple pics that should probably show that the throat/pole piece is a single machined part.

As you can see in the pic i posted above, it appears that they only made front plates with 1 inch holes and this throat/pole piece has a bit of a nose machined on it that fits into the 1 inch front plate hole.

I don't think it's a sleeve, besides being an additional part a sleeve would have to be tapered both inside and out making it a fairly complicated part to machine(read expensive) and since these are of the generation that adopted the plastic tangerine phase plug for it's low production cost above all else, i think it's important to factor in cost effectiveness when trying to determine how the assemblies were produced.

FWIW, these are from 9842 monitors which use the MR931-12, the drivers mate perfectly to the horn's 7/8 inch throat, with not so much as a "bump" and the joint between driver and horn, which is my understanding of a proper fit.

I'm pretty confident that the engineers knew what they were doing and designed all of these components to observe constant and proper flare rates. I don't think they can be mixed and matched to the extent a lot of folks do and still obtain the same results as when the proper components are mated.

Just my .02..............

[Old Guy]

I have one of these with a loose tangerine, when time allows i'll dig into it and try to get a couple pics that should probably show that the throat/pole piece is a single machined part.

As you can see in the pic i posted above, it appears that they only made front plates with 1 inch holes and this throat/pole piece has a bit of a nose machined on it that fits into the 1 inch front plate hole.

I don't think it's a sleeve, besides being an additional part a sleeve would have to be tapered both inside and out making it a fairly complicated part to machine(read expensive) and since these are of the generation that adopted the plastic tangerine phase plug for it's low production cost above all else, i think it's important to factor in cost effectiveness when trying to determine how the assemblies were produced.

FWIW, these are from 9842 monitors which use the MR931-12, the drivers mate perfectly to the horn's 7/8 inch throat, with not so much as a "bump" and the joint between driver and horn, which is my understanding of a proper fit.

I'm pretty confident that the engineers knew what they were doing and designed all of these components to observe constant and proper flare rates. I don't think they can be mixed and matched to the extent a lot of folks do and still obtain the same results as when the proper components are mated.

Just my .02..............

Drat this foggy old brain...:doh:

I remember a conversation with some of the really whiz bang Altec people one of my trips out there in 72-ish.

But I think John Hilliard, referencing small formats...said something like "the horn flare starts in the driver".

Now that's drifting back, and I wonder if in the thin design they just moved that part out to the horn...

It sure sounds like he was talking about something along these lines..

GM- any observations?

[Panomaniac]

Where is GM? Not seen him on the forums lately. Hope he's OK.

[Cal Weldon]

He posted here earlier today and just posted at diyAudio.