PA series horns - usable for Hi-fi?

[GM]

Originally posted by Dave H.:
The main reason I was curious about the PA series is the dimensions of the 511A from the 1975 catalogue:Horn and Throats (1975)
The catalogue lists the 511A as 18 1/2" high and 17 3/4" deep and 8 lbs. heavier than the 511B.

<font size="2" face="Verdana, Helvetica, sans-serif">Greets!

The 511A is a paging horn so has no flange mounting holes, instead using an adjustable mounting bracket: http://www.lansingheritage.org/image...orns/page2.jpg

WRT dims, both my 511Bs measure ~23-5/8" W x 10-1/2" H x 18-3/8" D, so don't rxactly match any listed dims I could find, but my SWAG is that the most listed dims of ~23-5/8" W x 10-5/8" H x 18-1/2" D are 'worst case' due to production tolerances and there's no reason for the 511As dims to be any different unless the height is increased to account for its mounting bracket. Since the 511A/Bs weight is listed as 17-3/4 lbs, apparently its depth was substituted for its height and weight for its depth on this page and just copied for the '78 catalog.

Anyway, it appears that all of the 511's dims are off one way or another, including their weights.

GM

[GM]

Greets!

Thanks for sharing! Did they remove the mounting tabs or relocate them further forward?

1.25"?! The large format drivers have a 1.4" exit, too big a mismatch for decent performance.

I'm not familiar with current rock guard and undercoatings, but historically they must be layered on pretty thick to work well. Most folks just damp the 'lips' and currently I use self adhesive bitumen/tin foil damping material on them with some high tension coil spring 'dampers' inside the horn to attenuate the worst of them, but you will have to mount them in a sandbox or similar to mass load them below their passband to make them as 'dead' as practical.

GM

[Steve Mac]

Originally posted by GM:
Greets!

Thanks for sharing! Did they remove the mounting tabs or relocate them further forward?

1.25"?! The large format drivers have a 1.4" exit, too big a mismatch for decent performance.
....

GM

<font size="2" face="Verdana, Helvetica, sans-serif">1 - 7/16"

[bfish]

If you HAD to express it as a fraction, it would be 1-2/5".

If you HAD to express it as a more common US standard fraction, the closest would be 1-13/32".

But it's not. It's 1.4". Always has been, always will be.

[Steve Mac]

Originally posted by bfish:
If you HAD to express it as a fraction, it would be 1-2/5".

If you HAD to express it as a more common US standard fraction, the closest would be 1-13/32".

But it's not. It's 1.4". Always has been, always will be.

<font size="2" face="Verdana, Helvetica, sans-serif">slow down fish...I have a pair of 511-e's and a ruler and I measure 1-7/16"

jeepers...