Old alnico 10"

[TroelsM]

Hi.

I pulled these from a set of old B&O speakers. They where used in a closed box of approx 50L.

I'm not interested in a closed box of that size so i took them out for some other use.

They seem to have a descent Xmax and run a 40Hz pretty clean. When stopping the moving come with my fingers I don't feel a lot of force (= low BL?), which corresponds with the smallish magnet and closed box use.

The question: What to with them? ( yes I could measure the TS-parameters...)

I have a set of old 8" and i thought of using the 10" as passive slaves (perhaps with added weight and/or some circuitry on the coils to control cone-movements). Whats the chance of this actually working? My thinking is that when used in a small box a slave will resonate at some resonance-freq determined by the box-volume and the slave-parameters. The parameters could to some extend be changed in the above mentioned ways.

Please be kind in your critics.. My electro-acoustic knowledge is packed away somewhere in the back of the brain...

Regards TroelsM

[Zen Mod]

using them as passives will be sacrilege .

[tinitus]

Subwoofer

[planet10]

Pictures of the front, anddoes it have any markings? Can you measure them.

dave

[ScottG]

Originally posted by TroelsM
Hi.

I pulled these from a set of old B&O speakers. They where used in a closed box of approx 50L.

I'm not interested in a closed box of that size so i took them out for some other use.

They seem to have a descent Xmax and run a 40Hz pretty clean. When stopping the moving come with my fingers I don't feel a lot of force (= low BL?), which corresponds with the smallish magnet and closed box use.

The question: What to with them? ( yes I could measure the TS-parameters...)

I have a set of old 8" and i thought of using the 10" as passive slaves (perhaps with added weight and/or some circuitry on the coils to control cone-movements). Whats the chance of this actually working? My thinking is that when used in a small box a slave will resonate at some resonance-freq determined by the box-volume and the slave-parameters. The parameters could to some extend be changed in the above mentioned ways.

Please be kind in your critics.. My electro-acoustic knowledge is packed away somewhere in the back of the brain...

Regards TroelsM

Its gotta be a high q woofer, best to use that as a "helper" midbass driver open baffle on a fairly small baffle (perhaps 15 inches in width).

Basically a 2.5 crossover with the ".5" near the fs of the 8" driver (assuming it has a fairly high "q" as well and the fs is around 100 Hz). It should also be used open baffle.

There will be almost no "punchy" quality to the sound.. but then you can achieve that with an active subwoofer that has a fairly high lowpass filter.

Of course the above suggestion will be nothing more than "dabbling" with the drivers until you measure them and determine how they can be best "blended" with proper crossovers. But it shouldn't cost much and it should give you an idea if your are on the right "track".

[Rolf Zetterberg]

Probably Peerless C100W or D100W.The first has a 32mm voice coil.Fr=40Hz.The latter has a 38mm voice coil.Fr=35Hz.From around 1966.