Just got some 511-B Altec Horns.

[bowtie427ss]

Can anyone confirm this 9lb weight for the 811 ?

In a few minutes, everything is out in the garage, i think i have to get an 811 off the ceiling.

Physically, the EH-800 is a good deal smaller, no bell portion or vanes, and just about anywhere you measure the EH will be twice as thick as the Altec, takes the resonant frequency down pretty low.

 

[bowtie427ss]

Circa 1966 511B

Circa 1973 811B

I'm sure the weights will vary a bit between generations/vintages, maybe a pound or two at most.

 

[EarlK]

Thanks a lot for the effort Bowtie ! ( much appreciated )

 

[bowtie427ss]

I've heard 511s ring before when used in concert level presentations

Certainly, many systems have inadequately braced and damped bass enclosures, once excited, the cabinet easily transmits this unwanted mechanical energy into the horn that's rigidly mounted to it, and the horn will effectively turn some of that energy back into audible acoustic energy.

Once upon a time i dug deep into horn theory, including the forces of acceleration and deceleration imparted into the horn/driver from the physical motion of the diaphragm. when Altec went from alnico to ferrite motors in their large format drivers, they incorporated a huge mass of cast steel into the throat of the driver to keep the total weight up around 30lbs. This mass is absolutely necessary in order for those drivers to maintain the same low distortion levels of the Alnico drivers. Less mass would not be able to overcome the acceleration and deceleration forces, and the distortion would have gone up.

 

[bowtie427ss]

Thanks a lot for the effort Bowtie ! ( much appreciated )

Very welcome!

 

[g..v]

I really hope bowtie isn't listening at 130 db

 

[bowtie427ss]

I really hope bowtie isn't listening at 130 db

No worries, i sent her down the road some time ago.

 

[elitopus]

I really hope bowtie isn't listening at 130 db

I say smoke 'em if you got 'em