interesting stuff (HXDA 30W combo content)

[CatStrangler]

I was planning on buying some new 12" speakers for my HXDA 30W 2X12 and couldn't find a manual for speaker ratings (W and ohms) so I popped the back off and there were two interesting discoveries. One is that the speakers (two celestion V30's 15 ohm, 30W) are wired in series, at least as far as I can tell and two, the wires are actually soldered to the speaker terminals. While I had the back off, I plugged in and listened to the amp, and found the fully open back sound quite pleasing, at least for cleans, I haven't cranked it up yet. Based on what I found I think I will buy an open/closed convertible cabinet from mojotone and and just run it through an extension cab. I have always wired series and was going to order 2X 4 ohm speakers. Any reasons to go specifically series or parallel? anyone else digging the fully open combo with the stock speakers?

 

[Blues Trucker]

15 ohm?

 

[CatStrangler]

yep they say 15 ohms. here is a pic of the wiring.

 

[László]

Funny, those look more like Heritage Series G12M Greenbacks than V-30s. And the 15 ohm rated impedance kind of confirms the diagnosis.

Also, I would expect soldered leads like the ones on your PRS amp, on a quality speaker cabinet. It's a more solid, road-worthy connection than spade lugs, which can fall off a speaker in transport.

I honestly can't tell whether those are wired series or parallel, maybe someone else can chime in. Most PRS 2x12 cabs have two speakers wired for 8 ohms.

 

[CatStrangler]

Funny, those look more like Heritage Series G12M Greenbacks than V-30s. And the 15 ohm rated impedance kind of confirms the diagnosis.

Also, I would expect soldered leads like the ones on your PRS amp, on a quality speaker cabinet. It's a more solid, road-worthy connection than spade lugs, which can fall off a speaker in transport.

I honestly can't tell whether those are wired series or parallel, maybe someone else can chime in. Most PRS 2x12 cabs have two speakers wired for 8 ohms.

Ha! Les you are right, these are not V30's! They do read G 12H! The specs for this amp were V30's and I have been dogging them all along. This is the first time I opened up the back, and never actually checked. Interesting! I do like the sound with the back off more, even more interesting!

 

[CatStrangler]

It's a more solid, road-worthy connection than spade lugs, which can fall off a speaker in transport.

No disagreement Here, I just didn't expect to get out the soldering iron for a speaker change

 

[justmund]

Well that's weird. Mine are V30's, 16ohm in parallel.

I seem to remember yours being from the same batch? Limited run of 10 or something in 2011/2012?

 

[justmund]

p.s. yours look like parallel to me

 

[CatStrangler]

Well that's weird. Mine are V30's, 16ohm in parallel.

I seem to remember yours being from the same batch? Limited run of 10 or something in 2011/2012?

hmm, I think your right, I have used 4ohm speakers in series to get to 8 ohm. for 15-16 ohm speakers to reach 8 ohm, they should be wired in parallel.

http://www.eminence.com/support/wiring-diagrams/

 

[justmund]

Yeah 1/Rt=(1/R1 + 1/R2) for parallel, Rt=R1+R2 for series...

 

[László]

Incidentally, the difference between 15 and 16 ohm rated impedance is negligible, and the impedance of a speaker varies according to the frequency anyway.

 

[Blues Trucker]

Can someone explain 15 ohms to me? Ive never heard of a 15 ohm speaker before.

 

[László]

Can someone explain 15 ohms to me? Ive never heard of a 15 ohm speaker before.

Greenbacks were nominally rated 15 ohms back in the 60s. The Heritage series tries to replicate the originals down to the rated impedance and what was on the stickers.

It's an entirely unimportant distinction whether a speaker is rated at 15 or 16 ohms. You treat it as a 16 ohm speaker. It's a nominal rating and we're not talking NASA tolerances when it comes to guitar speakers anyway.

The fact is that speaker impedance varies with frequency, that is, with the notes being played on the guitar, and your amp faces a different impedance load based on that anyway. So a given loudspeaker could offer an impedance of 4 ohms at, say, 100 Hz and 40 ohms at 2500 Hz (and yes, I pulled these numbers out of the air, but they might not be too atypical for dynamic speakers driven my a musical instrument).

While there may seem to be general conventions in loudspeaker impedance and amp output taps, there really aren't. Greenbacks pose no problem for any guitar amp, don't worry.

 

[sws1]

Ha! Les you are right, these are not V30's! They do read G 12H! The specs for this amp were V30's and I have been dogging them all along. This is the first time I opened up the back, and never actually checked. Interesting! I do like the sound with the back off more, even more interesting!

If those say G12H30, that's another speaker all together. Greenback typically refers to the G12M speakers (think, late 60s rock). If you have G12H speakers, those are often a bass-ier version (think, Hendrix).

One thing you could try, in addition to 2 V30s in parallel, is keeping one of the H30s and pairing it with a V30. That's a very common combination.

 

[CatStrangler]

If those say G12H30, that's another speaker all together. Greenback typically refers to the G12M speakers (think, late 60s rock). If you have G12H speakers, those are often a bass-ier version (think, Hendrix).

One thing you could try, in addition to 2 V30s in parallel, is keeping one of the H30s and pairing it with a V30. That's a very common combination.

Definitely will consider, Thanks!

 

[Boogie]

p.s. yours look like parallel to me

Yes, they are.

I'd be very interested in comparing a pair of greenbacks to a pair of V 30s in a pine 2x12. Veeeery interesting...

 

[tabl10s]

No disagreement Here, I just didn't expect to get out the soldering iron for a speaker change

Sound will be better too.