Help me choose a speaker

[Helmholtz]

I was always under the impression that a Celestion is not meant for a open back combo cabinet. I do know people who run vintage 30's in Fender combo's though.

Many good sounding combo examples with Celestions: Marshall Bluesbreaker, Vox AC30, Fender Twin with Vintage 30s, Matchless and other boutique combos.

[Chuck H]

EVM12L

[Chuck H]

I'm a Celestion guy to be sure. All my personal amps and half the amps I've built for others have Celestion speakers in them. That said...

Being that the OP heard a 2X12 Jensen cab with the amp and liked it I think that the best that can be done is the EV for a 1x12 combo design. This is sort of chapter and verse for the genre so I'm surprised no one mentioned it before me.

[The Dude]

Can you (the op) post a schematic? There may be a quick mod (or 2) that can be done to better tune the amp for the speaker you have. For instance clipping one leg of a bright cap or something of the sort- something easily done and easily reversible.

[Chuck H]

This^^^^^^^^^^^^^^^^^^^^^^^^^^

I also find that the NFB loop is a good place to tune an amp to a speaker. The amount of feedback and a tuned circuit (fixed values for presence/"resonance") can make a big difference.

[Helmholtz]

EVM12L

Agree that an EVM12L is probably the best overall option for a 1x12 cab (think Mesa Boogie). Didn't know that it's still available. But expensive and heavy.

[mozz]

If the speaker is new, maybe it needs to be broken in, play some rap music 8 hours while you are at work all day. I do have a EVM12L here in a convertible cabinet, heavy is not the word. I have heard they make a good amp sound great and a bad amp sound bad.

[vintagekiki]

Hi everyone. Very long time since I was last here, but suddenly got the itch to build an amp again.

I just finished a Master Volume amp, and it sounds just like I want it plugged into my old 2x12" cab with Jensen "special design" speakers (whatever that means). Medium gain big, bold, like AC/DC in 1981.

Problem is that this was meant to be a 1x12" combo. I chose a Celestion G12H, thinking it would do the job, but it sounds like a thin, flabby, lifeless 10" in comparison.

I haven't really that much experience with different speakers, so I hope someone here can help. Is there a 12" speaker that can do the job in an open back combo? Opening up the 2x12" cab to try one of those is a terrible job, and I don't really want to butcher it.

Regards
Jan

https://celestion.com/

https://celestion.com/product/17/g12h/
listen to Tone Samples ¹⁾

Why did you get attached to the Celestion G12H. Why don't you choose Jensen "special design" when you have that sound in your ear.

Each speaker has its own story for which it is designed, both for tone color, so for dB efficiency.

The volume of the cab in which the speaker is installed is important. Small and thin cab, the sound is shallow. Closed cab of appropriate volume, sound is rich. The hole (aperture) at combo amps (semi-open cab) behaves like some kind of bass reflex.

[Mick Bailey]

You can see a plot of the frequency response fer a given enclosure and speaker combination using WinISD.

I avoid recommending speakers because listening preferences are highly personal - like recommending pickups. It's like recommending to a stranger how much salt they should have on their steak. A few years back I sat with a guy auditioning speakers for a 5E3 I built for him. We had seven and to me a G12H30 sounded best (which I had taken from my own semi-open back combo). He went with an Eminence in the end - can't remember which - could have been a cannabis rex - but with each one there were plenty of differences of opinion.

[Hallingamp]

Why did you get attached to the Celestion G12H. Why don't you choose Jensen "special design" when you have that sound in your ear.

Fair point. I don't have that much experience with different speakers. From reading reviews I was under the impression that the G12H would sound a bit bigger and tougher than a G12T-75 - a speaker I liked in my old Marshalls. I was going for "as big sounding as possible" in a small box. Unless there's something REALLY wrong with the one I got, it turned out to be the exact opposite.

I got the Jensen C12K yesterday, and voila! Amp sounds very good now.

I posted the schematic earlier in this thread, but it's the MV channel from the Marshall model 2000 into a 4xEL84 power amp with no negative feedback.

Thanks for all the replies!

Jan

[J M Fahey]

FWIW, and you will be surprised, the "cheapo Bugera" everybody despises so much (as if price were a parameter, I never found it in any datasheet or schematic) ... are actually Italian Jensen!
A modern version somewhare between C12N and C12Q, actually very very close (if not exact same) as MOD1270
Not surprising you like them, IF you like Jensen.







Italian Jensen JCH1270
FWIW "CH" means "Chicago", initial batch was made using old Jensen Chicago plant dies bought by Recoton at auction and probably by the pound as scrap metal or not much more, and sent to SICA Italy for production.





For comparison, original 60´s Jensen 12Q pulled from a Silvertone cabinet, smaller magnet (Q size) but same unique frame:



Earliest Bugera ads (long ago) boasted of their Italian made Jensens.
I´m quite certain at some later point ULI either bought a die and machinery setup from SICA or Jensen to make them himself at lower cost in China or plain ripped them.

People may despise them either because they hear with their wallets or simply (which would be more justified), because they expect Celestions in their cabinets, which they are not.
Still killer speakers in their own right.

[Helmholtz]

Great info JMF. Unfortunately only one of your pictures (Italian Jensen) shows here.

[J M Fahey]

Weird.
I used the (new for me) "Upload to Server" feature in new Forum Software.
If still invisible to others I´ll upload them to Imgur or something and post links here.
Still unskilled on the new stuff.
Only 5th image (out of 6) is from an external link, all others were already in my own hard disks.

[Helmholtz]

Only fifth picture shows here.
I had the same problem with the new software a while ago uploading a picture from my computer. I could see it but not the others. I later managed but dunno what I did differently.

[pdf64]

Yey, Juan returns! Hope you’re well and busy