288L connection to 1285A Xover

[Altec Best]

Jeez, you mean those aren't just nightmares?

Not if they pay lots of cash !

[Altec Best]

The jumpers go to the 1200 Xo frequency taps (in the picture, post #4) and to the ( + positive) taps of the HF & LF terminals.If you move the jumpers over to the 800 Hz taps the crossover will now have a 800Hz cutoff,and so on.My 1285's also came with a 30923 attenuator board for matching a medium efficiency woofer like the (411).Your crossover should have a slider switch for changing crossover frequency if it is the 1285-8A. I hope this helps.

[DSauro]

The jumpers go to the 1200 Xo frequency taps (in the picture, post #4) and to the ( + positive) taps of the HF & LF terminals.If you move the jumpers over to the 800 Hz taps the crossover will now have a 800Hz cutoff,and so on.My 1285's also came with a 30923 attenuator board for matching a medium efficiency woofer like the (411).Your crossover should have a slider switch for changing crossover frequency if it is the 1285-8A. I hope this helps.

John, then what are the stainless three slot jumpers that are on the 500hz taps in your picture for?

[Altec Best]

John, then what are the stainless three slot jumpers that are on the 500hz taps in your picture for?

Hey Dave ! It is some sort of bridge for bridging the taps.If you loosen the screws it slides out and you can put it on any of the taps.(What purpose ??) How does it help,don't know.

I'm uploading some pics they will be up in a minute.

[DSauro]

Hey Dave ! It is some sort of bridge for bridging the taps.If you loosen the screws it slides out and you can put it on any of the taps.(What purpose ??) How does it help,don't know.

I'm uploading some pics they will be up in a minute.

Mine came with them also. That's what I've been using to change freq's. Now your photo's make me question whether a hard wire jumper such as yours maybe necessary. ??

[Altec Best]

They have holes in the top so spade lugs could be used I think take a look. If you slide it out and flip it,put the screws through the holes and mount it then spade lugs could be used.That was around the time that Altec went to the spade lugs on the Large format drivers IIRC.

[DSauro]

John, do you have yours in service currently? I do, and I just loosened those jumpers, and moved them from one frequency to another. They change frequency without being directly externally wire jumped to the hf & lf lugs. Try it. Without them you will get no sound. I really didn't want to think I've been going full range with my 515's & 288's for the last 16 month's, especially with an S.S. amp at high volume levels, usually. I would think I would have fried a voice coil, or diaphram by now.
Sorry to hijack this thread. Hopefully this part of the discussion will be beneficial to the OP.

[Altec Best]

John, do you have yours in service currently? I do, and I just loosened those jumpers, and moved them from one frequency to another. They change frequency without being directly externally wire jumped to the hf & lf lugs. Try it. Without them you will get no sound. I really didn't want to think I've been going full range with my 515's & 288's for the last 16 month's, especially with an S.S. amp at high volume levels, usually. I would think I would have fried a voice coil, or diaphram by now.
Sorry to hijack this thread. Hopefully this part of the discussion will be beneficial to the OP.

No I don't at the moment. I had them in service for a bit awhile back to do some testing and to make sure they were working properly after i purchased them.I left those bridges at the 500 Hz taps.Just the way I received them.I need to take the cage off to examine them a bit more closely now.I have been working on my project so I haven't really messed with them too much.I just been working a lot so I've been just a weekend warrior lately.

[DSauro]

Thanks John, input from others who have used 1285-8B's, or are using them currently would be beneficial, and appreciated.