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MikeM
04-19-2017, 03:51 PM
Hello all, been a few years since Ive checked in here.
New purchase (off ebay) Maybe you seen these a couple of weeks ago Here http://www.ebay.com/itm/JBL-PRO-TWO-SPEAKERS-IN-WORKING-CONDITION-SEE-LIST-OF-COMPONENTS-/222446366734?nma=true&si=kYblavuMdSVmbb5NZ2Q11W8j4%252BA%253D&orig_cvip=true&rt=nc&_trksid=p2047675.l2557
Anyway these are pretty cool, 3115b Crossovers along with a 7K crossover. Take a look at the pictures on the post please. I need to reduce the output of the Compression driver 3-6 db. How could I do that?
Cheers
Will you believe that there is NO insulation in the cabinets?
Mistake these are the 3115A versions

grumpy
04-19-2017, 04:18 PM
First, looks like it may be a 3115 (no "a" suffix, and I'm not aware of a b version)

Next, you've turned the attenuation knob to note changes?

You could add an L-pad between the crossover and 2440, or an equivalent pair of resistors to knock the level down without changing the crossover frequency (or in-band response much).

fun set of parts and nice price :)

MikeM
04-19-2017, 04:31 PM
First, looks like it may be a 3115 (no "a" suffix, and I'm not aware of a b version)

Next, you've turned the attenuation knob to note changes?

You could add an L-pad between the crossover and 2440, or an equivalent pair of resistors to knock the level down without changing the crossover frequency (or in-band response much).

fun set of parts and nice price :)

Thanks for reply, Yes they are the 3115A version. Crazy the picture don't show that but there is the 3 way toggle switch on there. So there is a 3 way switch in addition to the rotary switch. Like to still reduce the output a bit. Id dig into the crossovers and swap out a resistor so the toggle reduces the output a touch more.

grumpy
04-19-2017, 05:22 PM
Ah, couldn't see the switch.

If I recall correctly, that switch throws in a compensation for constant directivity horns, which you shouldn't need.

Similar to this: http://www.audioheritage.org/vbulletin/showthread.php?33057-Alternative-to-tapped-inductor-in-3110a-or-3115a&p=334921&viewfull=1#post334921

That said, the options are pretty much what I said before.

MikeM
04-19-2017, 07:20 PM
Ah, couldn't see the switch.

If I recall correctly, that switch throws in a compensation for constant directivity horns, which you shouldn't need.

Similar to this: http://www.audioheritage.org/vbulletin/showthread.php?33057-Alternative-to-tapped-inductor-in-3110a-or-3115a&p=334921&viewfull=1#post334921

That said, the options are pretty much what I said before.

Many Thanks for the help! Would these be a good starting point http://www.ebay.com/itm/L-Pad-100W-Mono-3-8-Shaft-16-Ohm-/221540014914?hash=item3394d05b42:g:QmYAAOSwd4tUBzo 6

grumpy
04-21-2017, 07:45 PM
That's what I'd be looking at.

BMWCCA
04-21-2017, 08:55 PM
The incorrect knob on the crossover with the three-way switch is confusing. The four-position knob is used for the variable L-pad, not the three-way switch.

grumpy
04-21-2017, 10:58 PM
Yup. Kinda assuming that had been tried.
If not, good time to try before spending $ on additional attenuation.