Crossover help for Altec 416-8C, 511B, 902-8B

[Mowa]

Hi,
I just had the opportunity to get a pair of used Altec speakers. The cabinet are 816a, woofer 416-8c, tweeter 902-8b, horn 511b, but the crossover network attached are JMTEC DN 8h8.
Initially, try connecting it with a 6l6 push-pull tube amp. The bass comes out very thin. Not sure if it's a crossover problem or not.
I would like to build crossovers to matching these up. Dose anybody have a crossover spec. I can use to get started.

 

[bowtie427ss]

You've struck the double whammy.

a) 816 is a mid-bass horn, it has not nearly enough reflex volume to extend the bass much below the horn's LF cutoff(~90hz), response will roll off pretty quickly below that.

b) the flat magnet 416-8C is known for it's lackluster LF performance making it perhaps the least desirable woofer in the 416 family.

A subwoofer, or a few are required for full range playback.

Additionally, and i know you didn't ask, but it will come up, the 902-8B's most likely have 7/8 inch throats, measure them. 511 requires a driver with a 1 inch throat to achieve the seamless transition required between horn and driver. Folks have successfully made adapters to restore a proper continuous throat angle.

but the crossover network attached are JMTEC DN 8h8

Looks like it was built on an original Altec chassis using similar laminated core inductors.

Are you sure the cabinets aren't JMTEC?

They look a lot like the early Queen of Queen model 5000.

 

[Mowa]

You've struck the double whammy.

a) 816 is a mid-bass horn, it has not nearly enough reflex volume to extend the bass much below the horn's LF cutoff(~90hz), response will roll off pretty quickly below that.

b) the flat magnet 416-8C is known for it's lackluster LF performance making it perhaps the least desirable woofer in the 416 family.

A subwoofer, or a few are required for full range playback.

Additionally, and i know you didn't ask, but it will come up, the 902-8B's most likely have 7/8 inch throats, measure them. 511 requires a driver with a 1 inch throat to achieve the seamless transition required between horn and driver. Folks have successfully made adapters to restore a proper continuous throat angle.


Looks like it was built on an original Altec chassis using similar laminated core inductors.

Are you sure the cabinets aren't JMTEC?

They look a lot like the early Queen of Queen model 5000.

Thank you for the informations.
So it's not a problem caused by using the wrong crossover, is it?
The cabinets are all made to order from real wood. Base on the dimensions of the 816a.
Everything seems to have been designed quite incorrectly.
May need to find a new cabinet. Or get a new woofer if I don't want to add a subwoofer.

 

[bowtie427ss]

So it's not a problem caused by using the wrong crossover, is it?

Probably not.

The cabinets are all made to order from real wood. Base on the dimensions of the 816a.
Everything seems to have been designed quite incorrectly.

One must understand the limitations of the 816A. It was not designed to produce low bass. The specifications in most of the old catalogs where they claim response down to 35hz is grossly incorrect, and they never corrected it.

The response is usable down to 50hz with ample EQ and LPF, it'll be some 10db or more rolled off down there.