Finding the impedance of an unmarked speaker

[ItsaBass]

Anyone know how to do it? I was just given a 10 inch G-K speaker today, and I want to find out if I can use it to replace the shredded stock speaker in my 50-year-old Gibson Skylark amp. It requires 8 ohms.

Thanks.

[GoldenVulture]

Re: Finding the impedance of an unmarked speaker

Use a multi meter. They usually read at a couple of Ohms lower than what they are. EG:Most 8 Ohm speakers will read around 6 Ohms on a multi meter.

[the guy who invented fire]

Re: Finding the impedance of an unmarked speaker

Use a multi meter. They usually read at a couple of Ohms lower than what they are. EG:Most 8 Ohm speakers will read around 6 Ohms on a multi meter.

There ya go!

If you hit the terminals with a meter expect to see something around 6.5 or 14.5 give or take...maybe even 3...3 or so would be a 4 ohm, 6 or so would be 8 then 14ish is 16...

[ItsaBass]

Re: Finding the impedance of an unmarked speaker

Thanks for the tips, fellers. Unfortunately, the speaker reads at 13.8, so I cannot use it. And now I have one more useless thing sitting around. Damn!

I think one of those $40 15W Weber 10-inchers is in my future. I'd love to get a CVA-10 or CTA-10, but $85 is a bit much to invest in this amp when all it does is serve as a bedroom amp or occasional practice amp.

[Soulcrusher_X]

Re: Finding the impedance of an unmarked speaker

Why can't you use it? It makes sound, correct? If the Skylark has 8 ohms on it, then it doesn't want to see any LESS than 8 ohms. More is okay. IE: 8-16ohm speaker on a 8ohm xformer setting.

Sometimes, a higher impedance speaker on a low impedance xformer setting smoothes out the tones a sliver.

[the guy who invented fire]

Re: Finding the impedance of an unmarked speaker

Is that the brown "tolex" Skylark with the front mounted single volume control??

If so just grab a Weber Signature 10 inch...I like the alnico version with the ribbed cone!

[ItsaBass]

Re: Finding the impedance of an unmarked speaker

Is that the brown "tolex" Skylark with the front mounted single volume control??

If so just grab a Weber Signature 10 inch...I like the alnico version with the ribbed cone!

Yep, that's the amp, and that's the speaker I was looking at. I was actually leaning toward the straight cone, though.

The amp sat in an abandoned house on BLM land in the desert for at least 15 years, near a window. It was covered in an inch of desert dust and full of rat's nests. It worked, but would shut off after about 30 minutes of playing. Paid $100 to have it fixed, and it works great now. But that speaker is like a saltine cracker. Brittle as ****, and has a hole in it. The amp works fine, but that speaker is really dragging it down.

[the guy who invented fire]

Re: Finding the impedance of an unmarked speaker

Yep, that's the amp, and that's the speaker I was looking at. I was actually leaning toward the straight cone, though.

straight cones are cool I guess...sort of a cheap/trashy sound, I prefer the slightly cleaner more articulate tone of a ribbed cone most of the time.

[ItsaBass]

Re: Finding the impedance of an unmarked speaker

straight cones are cool I guess...sort of a cheap/trashy sound, I prefer the slightly cleaner more articulate tone of a ribbed cone most of the time.

Exactly why I want the straight cone for this amp. I am hoping for "good trashy," unlike what is in there now, which is "bad trashy" from that 50-year-old, sun-baked, holey stock speaker.

[SoPhx]

Re: Finding the impedance of an unmarked speaker

+1 on the Weber Signature alnico...cheap and will get you pretty close to a early P10R tone.

[ItsaBass]

Re: Finding the impedance of an unmarked speaker

Why can't you use it? It makes sound, correct? If the Skylark has 8 ohms on it, then it doesn't want to see any LESS than 8 ohms. More is okay. IE: 8-16ohm speaker on a 8ohm xformer setting.

Sometimes, a higher impedance speaker on a low impedance xformer setting smoothes out the tones a sliver.

I am operating under the rule of thumb (possibly incorrect, as rules of thumb can certainly be) that solid state amps could go with a higher impedance load with no problem, but tube amps were more sensitive to having proper impedance matching.

[the guy who invented fire]

Re: Finding the impedance of an unmarked speaker

If the amp wants to see 8 ohms a tube amp can handle 100% mismatch in EITHER direction, meaning a 4, 8 or even a 16 ohm speaker will work in your amp however in my experience if the amp wants to see 8 and you go to 16 the amp will loose punch and sound a little gutless...not a great thing in a single ended 5 watt amp...

[the guy who invented fire]

Re: Finding the impedance of an unmarked speaker

Exactly why I want the straight cone for this amp. I am hoping for "good trashy," unlike what is in there now, which is "bad trashy" from that 50-year-old, sun-baked, holey stock speaker.

Then go straight cone.

[ItsaBass]

Re: Finding the impedance of an unmarked speaker

Thanks for all the info.

[Soulcrusher_X]

Re: Finding the impedance of an unmarked speaker

I am operating under the rule of thumb (possibly incorrect, as rules of thumb can certainly be) that solid state amps could go with a higher impedance load with no problem, but tube amps were more sensitive to having proper impedance matching.

Tube amps are a little more forgiving, but I try to keep the mismatch with the speakers being the higher number, but that's just me.

Though, like TGWIF said, since it's a single-ended 5 watter, keeping as close to the suggested rating will probably keep the amp from sounding too 'choked'. Who knows, the little extra resistance may allow you to open it up more and it may end up sounding good. Try it out, it could sound awesome. Though, going with a Weber is never a bad idea.