single speaker operation in a 2x12

[TFM94]

Hi TB,

I have a question about cabs. Guitar cabs, to be honest. I hope that's ok. Let me know if it's not.

I recently got to try the weber black shuck speakers and I was very impressed. So much so that I made plans to build a 2x12 guitar cab with black shucks to be used together with a 2x12 V30 cab as a little stack. Should sound pretty good.

Here's the catch: I want to use this cab both at home and at my bands practice space. At home (and for gigs) I'd combine it with a 16 Ohm 2x12, but in the practice space we have an 8 Ohm cab. My amp only takes a single 8 ohm, single 16 ohm or two 16 ohm loads (Orange Rockerverb 50 MkIII).

Does it make sense to use two 8 Ohm speakers with separate mono and stereo inputs so that I could use this cab as 16 ohm with both speakers activated or as 8 ohm in single speaker operation? The speakers have 200W power handling each, that would be more than enough. They might even be usable for bass (up to a certain power).

Does single speaker operation of a 2x12 cause a significant change in tone? Should I build a separator into the cab so that each speaker has its own sealed volume, or should I use an open back to take pressure off the second speaker cone?

 

[Aloe]

I'd just wire them in series, so you'd have a 16ohm cab (provided you have 8ohm speakers). turn down if it's loud, so no need for disabling one of the drivers.

you won't be able to use a 8ohm cab that you have in practice space with your head and a second cab either way.

 

[Killing Floor]

Attenuator?

 

[TFM94]

Attenuator?

My motivation for the single speaker use is not volume, but impedance. The Rockerverb has a built-in attenuator, so volume is not an issue.

you won't be able to use a 8ohm cab that you have in practice space with your head and a second cab either way.

I think I could use two 8 Ohm cabs with a series connection box to generate a total load of 16 Ohms, which I can connect to the single 16 Ohm output of the amp. I'm not talking about a daisy chain (which would be parallel) but a series connection of the two cabs.

Just after posting this I realized that the easiest solution might be two 8 Ohm 1x12 cabs: I can use one of them together with the 8 Ohm cab and both 1x12s with the 16 Ohm cab.

Another option would be the Weber Z-matcher.

 

[agedhorse]

If the cabinet have separate air spaces for each speaker then yes, but if your amp only handles an 8 ohm minimum load, I can’t see any advantage to using a single driver in any regard. Just use it as a 16 ohm 212 and be done with it.

 

[two fingers]

Yep. 16 ohms is the way to go. "Not getting all the watts out of your amp" won't matter one bit. You should be able to get stupid loud with a 16 ohm 212 cab.

I know a guitar player who can rip my face off with a 15 watt 112 combo. He's so loud I can't stand playing with him.

You'll be fine for volume. Honestly? I can't ever imagine your needing two of these cabs. One should be enough to cause serious hearing damage.

 

[TFM94]

Thank you all for the comments.

I should clarify: I play in a stoner rock/metal band (sabbath, red fang, mastodon, high on fire inspired stuff), and volume is not unheard of in this genre. I totally understand that a 1x12 would be loud enough, but two 2x12s would give a bigger (not louder) sound. I just got excited about the black shuck speakers and wondered how to incorporate them into my setup. It's a the same on bass: A compact 210 will be enough to handle most gigs, but it does sound better with the 810.

I'm also the only guitarist in the band, so I could use two separate cabs for a left/right kind of setup in live situations.

 

[byacey]

Better just to use your cab the way it was intended. No good comes from using attenuators, mismatched drivers in a single enclosure (Which is what you create by disconnecting one of the drivers), etc.

 

[Aloe]

I'm not talking about a daisy chain (which would be parallel) but a series connection of the two cabs.

well, you can do this, but if one single cab cable will go bad, you'll fry our amp.
if using 2x16, one cable goes bad and everything still works, but with one cab.

I also don't get the point, why you want to use one 112 and one 212 with one speaker disabled. just use the 212.

 

[TFM94]

Thanks for the comments. You are probably right in saying that there's nothing to be gained by using these unusual cab connections.

I might just order a single Weber black shuck speaker (8Ohm) and replace one of the V30s in my 2x12 cab with it. If I like the result I can still build a second 16 ohm 2x12 later on. This way it would be used as intended for the amp.

 

[agedhorse]

Why?

 

[TFM94]

Why?

Could you elaborate? What is so problematic about trying out a new speaker in my cabinet? It has the same impedance as the current speaker and has sufficient power handling. Using two or more different speakers in a cabinet is not unusual. Currently I'm running two V30s in my cab, with my suggested change I'd be running one V30 and one Weber Black Shuck in my cab. All 8 Ohm speakers all sufficient power handling.

Here's a tone demo of the Black Shuck and other speakers of the Weber Tone Cvlt series:
I think they sound pretty good, and distinctly different to the V30.

 

[agedhorse]

Go for it!

 

[baxter_x]

Go for it!

 

[Lostgallifreyan]

What is so problematic about trying out a new speaker in my cabinet? It has the same impedance as the current speaker and has sufficient power handling. Using two or more different speakers in a cabinet is not unusual.

It may not be unusual, but it IS a lottery you're likely to lose. This is a question often asked, often answered, and I'm going to guess that the response from @agedhorse is basically saying try it, you'll soon find out how badly it usually works.

Now, assuming you have two drivers that are the same, and WERE part of a specific cab design intended to use their (very) specific electrical and physical parameters, your notion of using them in series for 16 ohms is viable, assuming your amp can drive that properly. At least that way, they move together, and you'll get some efficiency from your cab.

 

[TFM94]

It may not be unusual, but it IS a lottery you're likely to lose. This is a question often asked, often answered, and I'm going to guess that the response from @agedhorse is basically saying try it, you'll soon find out how badly it usually works.

Now, assuming you have two drivers that are the same, and WERE part of a specific cab design intended to use their (very) specific electrical and physical parameters, your notion of using them in series for 16 ohms is viable, assuming your amp can drive that properly. At least that way, they move together, and you'll get some efficiency from your cab.

If we were talking about bass speakers, I'd totally agree. I have built several after careful calculation in WinISD and I'm aware of cab design around TS parameters. Note that this is for a guitar speaker cab where the impact of the enclosure is minimal, especially in open back cabinets.

EDIT: I found this on the Celestion website about guitar speaker cabinet design: "When designing a cabinet for guitar speakers, the cabinet’s size, shape and construction are of far higher significance than the internal volume. Guitar speaker cabinet design using Thiele Small parameters ignores these most fundamental aspects."

and

"As guitar speakers are different, so their cabinets are different to hi-fi or PA cabinets. Deep, thunderous bass is not required (the low E of a standard-tuned lead guitar is 82Hz). High frequency reproduction is a positive disadvantage, allowing unpleasant harmonics and electronic noise to be heard. Distortion-free sound would be a disaster."

 

[agedhorse]

A single driver powered in a 212 with a common air space results in cancellations as the unpowered driver serves to cancel a larger range of frequencies than “internet lore” might suggest.

If you don’t like the answers given, and already know the answer to your question, then why ask it?

 

[TFM94]

A single driver powered in a 212 with a common air space results in cancellations as the unpowered driver serves to cancel a larger range of frequencies than “internet lore” might suggest.

If you don’t like the answers given, and already know the answer to your question, then why ask it?

I was refering to @Lostgallifreyan's post, which I understood to be a response to my suggestion to replace one speaker in my current 2x12 cab, not my original suggestion to use it as a single speaker. In post #10 I already admitted that the connections as a single speaker cabinet are probably not great. From that point forward I was only considering to replace a speaker in my 2x12 (with both speakers always active), not to use a single speaker in a 2x12. Sorry if that was not clear in post #10.

 

[Lostgallifreyan]

Ok, I admit to overlooking the intent for guitar and not bass, but the way I see it, is if you consider optimising on general principle, you improve your odds, whatever the intent. There's not that much difference in bass and guitar fundamental frequencies so it's worth applying the principles equally. (Not many bass cabs go much below 80 Hz anyway, so if you want to go that low for a guitar, it is worth calculating as for bass purposes.)

EDIT: I don't know what Celestion are assuming about the frequency range and timbre of guitar cabs, so I going to leave my post as is so people can rip it to shreds if they want.

 

[bobdabilder]

Good times