Altec 511B horn recommended crossover frequency to woofer

[MerlinVSM]

Any recommendation for crossover frequnecy between the woofer and an Altec 511B horn.

Will the Altec 511B horn and a GPA 902 driver be fine with a crossover frequency of 500 hz or would 1000hz be more appropriate ?

Any information on the topic appreciated.

[hemicuda]

It would depend on the woofer you are using. But using Altec woofers, I'd say 800-1200 hz would be more appropriate. Any good Altec woofer should reach that high easily. You can cross the tweeter over at 500 hz but power handling will suffer some. Depends on how hard (loud) you are going to listen to them. Power handling really shouldn't be a problem seeing how efficient Altec horn drivers are anyways. In a normal room, the 902s should be really loud with only 10 watts each going to them. I personally think that they just sound better crossed over a little higher than stock. They don't sound as honky that way; a little more refined to me. I'm sure someone else that has more experience will help more than I can. Good luck and enjoy...

[Alien_Shore]

If I recall, some of the experts here have recommended to use the large format compression drivers if you want to cross at 500 Hz. While spec'd down to 500 Hz, I think you'd be pushing it with a 902 at that frequency. If you really want to use a small format driver, I think the recommendation was to go with one of the bigger-body units such as 802 or 808. Let me do a quick search and see if I can find that thread...

Edit: Here it is:
Best sounding combination for Altec 416a

[VolvoHeretic]

So, why did Altec use a 500hz crossover in my A7-500s?

[Panomaniac]

I dunno, but it doesn't sound great, at least what I've heard. Crossing up higher and flattening the mid-range hump helps a lot. I second the motion for 800-1200Hz.
Maybe they did it to push dialog forward?

[hemicuda]

I dunno, but it doesn't sound great, at least what I've heard. Crossing up higher and flattening the mid-range hump helps a lot. I second the motion for 800-1200Hz.
Maybe they did it to push dialog forward?

That's exactly what I was thinking too. I don't like the stock crossovers at 500 hz either. They probably did do that to enhance dialog, etc. I like a little of the midrange hump but in stock form it is a little too much for my taste...

[bowtie427ss]

Note that GPA and Altec 902's are NOT the same. Their phase plugs are different. I have no experience with the GPA.

IMO&E with Altec small format drivers, the alnico versions with annular slit phase plugs are best suited to the lower XO points.