Suggest 8" speakers for "Mini Twin"

[glebert]

I've got a silverface Bandmaster Bandmaster Reverb (70 Watt ultralinear). This is one with the tall cabinet. I want to make a replacement baffle that can take two 8" speakers and make this into a combo amp that you could still choose to hook up an external cabinet. Obviously an 8" speaker won't sound like a 12", but if anyone knows any that can do an approximation I would love to hear about them. The other hard parts are power handling (lots of 8" can only take 15 watts or so), can work in open back cabinet, and need to be wallet friendly as I don't even know if this is going to work out.

I am stealing this idea from Rob Robinette. Here is one he did with Fender C8R speakers. Those can be had for $50 each or so, which is probably the max I could justify spending. Those would be my baseline, I guess. Those are 25 watt speakers, and fairly low efficiency (93dB).

[The Dude]

I can't say how they sound and have no experience with them, but here's a link to some Peavey Blue Marvels from Mojotone for a great price. Maybe someone else here can say how they sound. They are also rated at 25W and 8 ohm.

https://www.ebay.com/itm/12400060031...Bk9SR9Kp6razZA

[Chuck H]

Didn't GK use2x8"s in their early guitar combos? They weren't taking on Twins but they were taking on single 12 combos with 2x8 cabs. What did THEY use???

EDIT: A little research... GK used 6.5" speakers for their little amps and moved to 10'S later and finally 12" combos as a competitive measure. But I did learn that their 6.5" and 10" speakers were made by Pyle. So I might look into 8" offerings in this brand. No promises.

[The Dude]

FWIW: I found this Blue Marvel vs Celestion comparison on YouTube. It's for the 12" version, but I think one could make a reasonable assumption based on this. Of course, it's a 12" instead of the 8" you're looking for, so keep that in mind.

[DrGonz78]

I rebuilt (redesigned) an old silvertone widowmaker which I had to replace the speaker. Had a blue marvel smaller than 8”, I think, but it sounded good.

[glebert]

Thanks for the replies everyone. I found out that I can get the C8R for just over wholesale through the shop I do contract repair for, so I am going to give those a try.

[J M Fahey]

Thanks for the replies everyone. I found out that I can get the C8R for just over wholesale through the shop I do contract repair for, so I am going to give those a try.

2 x C8R won´t stand a 70W Ultralinear amplifier.

At least 2 x C8Q (if available) and even that would be on the edge.

You need 2 x 50W RMS speakers at least..

I am talking the modern Italian ones, which sport Kapton voice coils, are glued with Epoxy, etc.

Forget old vintage Jensen ones, wire glued with nitrocellulose lacquer to paper formers.

IF you could fit two 10" there these would be perfect:
https://www.jensentone.com/mod-series/mod-10-70

or at least 2 of these:
https://www.jensentone.com/mod-series/mod-10-50

But in 8" size you are up for a very tough nut to crack.

Mind you, *I* make 8" 50 to 80W RMS guitar speakers to cover that niche (I make a 100W 2x8" SS combo) but not offering them, I am 10000 km and 2 tight Customs offices away.
But am well aware of what´s needed.

[Chuck H]

2 x C8R won´t stand a 70W Ultralinear amplifier.

Glad you brought this up because I had thought the same thing but failed to respond before this thread rolled off the daily feed. Then I forgot about it. But yes, this is absolutely true. My suggestion was going to be to wire up the internal speakers with resistive attenuation (note***). So the amp would be lower output as a combo but still full power when plugged into another cabinet as a head.

*** Feed the speakers through a 4R 50W resistor and then an 8R 50W resistor parallel to the speakers wiring.

[Justin Thomas]

I'd look at Eminence full-range or PA speakers. I had a 25W one in my Champ & it was great! I'm sure they'd have something that will handle 50W. That's just me.

Jusrin

[The Dude]

While I don't disagree with power rating statements above, it seems like the purpose of this is to have an easy practice rig. In my mind, you'd never run the amp at full output for practice so I'm not sure it's necessary to have speakers rated for full amp power. If the intention is otherwise, then yes you'd want speakers rated accordingly. If you want to keep up with a drummer, or use the amp in a live situation with a band, you'd use an extension cabinet anyway.

[glebert]

While I don't disagree with power rating statements above, it seems like the purpose of this is to have an easy practice rig. In my mind, you'd never run the amp at full output for practice so I'm not sure it's necessary to have speakers rated for full amp power. If the intention is otherwise, then yes you'd want speakers rated accordingly. If you want to keep up with a drummer, or use the amp in a live situation with a band, you'd use an extension cabinet anyway.

Yes, basically this.

[Chuck H]

So why not wire in two resistors that will make it so you can't blow up the speakers. Considering that speakers are expensive and an open load could damage other expensive components.

[glebert]

Update on this: Sounds great, just like a mini-Twin should. Considering the original non-speaker baffle was made of incredibly dense 3/4" particle board I don't think the two speakers (mounted on 7/16 plywood) really add much weight. More bass response than I expected, though obviously not quite as deep as 2x12. Grill cloth is outdoor fabric that came off an old patio bar. I'll need to find a better Fender badge for it and make a better speaker cable and probably add a couple low ohms power resistors too as chuck suggested.


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[Chuck H]

Ok, so... Did you include built in attenuation for those speakers? Or are you relying on the probability that they will never be put to the task? Attenuation is a guarantee where NOTHING means that it only takes one mistake to open the load and blow some transformers. Just sayin'.

[glebert]

I'll need to find a better Fender badge for it and make a better speaker cable and probably add a couple low ohms power resistors too as chuck suggested.
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Don't worry Chuck, I heard you.