Speaker / Amp impedance mismatch...

[MikeC]

You should always match your speaker impedance with the amp's impedance. This is safe and provides for maximum power to the speaker. But for a short time you should be OK to connect your 4-ohm speaker to your Pro Junior. Just don't dime it/thrash it. Turn the volume up slowly to ensure the speaker is sounding OK (i.e. it has no sound issue/rubs or it makes no sound whatsoever). Get the right impedance speaker back in there asap.

[Miza]

I have an Lpad attenuator, would it help the situation, or make it worse?

[MikeC]

I have an Lpad attenuator, would it help the situation, or make it worse?

Wattage of that L-Pad???
Much better if you just plug the speaker straight in IMO. Follow what I said & also ensure you have good connections.

[rickenbackerkid]

Probably a dumb question, but what if you just jammed a high-current 4 Ohm resistor in series with the speaker's coil?

This will work. But you want a big fat resistor that can handle the power. And you want to mount it securely.

[rickenbackerkid]

a 100% mismatch is fine, but your PJ will be working very hard to drive a 4ohm speaker. And the PJ's (if stock) have a cute small OT, so it's probably not the best practice. However I'd say go for it, but maybe don't use it like that all the time.

Also - if you're interested in a speaker for the PJ, I have a Celestion Vintage 10 I've been meaning to sell. It makes a PJ sound really big compared to the stock speaker.

[Miza]

Probably a dumb question, but what if you just jammed a high-current 4 Ohm resistor in series with the speaker's coil?

This will work. But you want a big fat resistor that can handle the power. And you want to mount it securely.

Something like
https://a.aliexpress.com/_m03SHMs

[rickenbackerkid]

Exactly. That's a nice one to use as you can mount it in the cab with a couple screws and use some heat shrink to cover the wires.

[sizzlingbadger]

If you use resistor then half the output power will be lost as heat in the resistor, it will essentially act as a silent, second speaker

Don't bother, just try the 4 ohm as Mike says.

[Dharmajester]

I highly recommend the Iron Man attenuator ( big version ). It's particularly transparent , will take 100watts and has a z matcher so you can set the input to the impedance of your amp's output and the output to the impedance of your speaker. Doesn't have a 2 ohm setting though so Super Reverb users are still in the land of the fucked.

[MikeC]

I highly recommend the Iron Man attenuator ( big version ). It's particularly transparent , will take 100watts and has a z matcher so you can set the input to the impedance of your amp's output and the output to the impedance of your speaker. Doesn't have a 2 ohm setting though so Super Reverb users are still in the land of the fucked.

That's a pricey solution!

[Miza]

I highly recommend the Iron Man attenuator ( big version ). It's particularly transparent , will take 100watts and has a z matcher so you can set the input to the impedance of your amp's output and the output to the impedance of your speaker. Doesn't have a 2 ohm setting though so Super Reverb users are still in the land of the fucked.

That's a pricey solution!

Indeed. The most I've spent so far on this cab is $25 on screws and bolts.

What cable do people recommend for making a speaker cables? Jaycar have a 16AWG speaker cable, but I've read ordinary power cable is also fine?

[AiRdAd]

My Fryette power station has got an input ohms selector (4,8,16) and output ohms selector (4,8,16) - I wonder if that means I can mismatch the speakers with the amp, as long as I've got the sectors correct. I always match the amp with the cabinet, but I should probably read the manual

[sizzlingbadger]

I highly recommend the Iron Man attenuator ( big version ). It's particularly transparent , will take 100watts and has a z matcher so you can set the input to the impedance of your amp's output and the output to the impedance of your speaker. Doesn't have a 2 ohm setting though so Super Reverb users are still in the land of the fucked.

That's a pricey solution!

Indeed. The most I've spent so far on this cab is $25 on screws and bolts.

What cable do people recommend for making a speaker cables? Jaycar have a 16AWG speaker cable, but I've read ordinary power cable is also fine?

5amp power cord is fine

[robthemac]

My Fryette power station has got an input ohms selector (4,8,16) and output ohms selector (4,8,16) - I wonder if that means I can mismatch the speakers with the amp, as long as I've got the sectors correct. I always match the amp with the cabinet, but I should probably read the manual

Yeah pretty sure the PS is designed for exactly this, can use any amp and cab.