Sound difference between 4x10 and 2x12 (both open back)

[ryanm74]

I have owned both 4x10 and 2x12 open back cabinets for guitar, and I find they vary, but how much of that is the particular speaker (quality, characteristics,etc.) and how much is an actual difference between basic sounds of 12s and 10s? I also wonder why it matters how much air the speakers move if speaker movement alone does not determine volume? If anyone can help me out with answers to these questions I would really appreciate it. I have googled and don't find the answers I am looking for.

[sliberty]

I am no expert, but sound is moving air. Period. So the is nothing other than air in motion that dictates volume.

Now there are a lot of factors that are related to how much air will be set in motion, and the size of the speaker cones is only one of those factors. One other is the efficiency ofnthe transfer from electro magnetic energy to mechanical energy (voice coil to cone). And I am sure there are many other factors that I know nothing about.

[9pins]

4 tens are tighter punchy, 12's got nice low's but can flab out sometimes

[LeeMo]

Do the math. Pi R Squared. 4-10's almost equals 2-15's in the cone area. However a ten has less cone mass , therefore reacts to transients more efficiently. IE more punchy. Also, the cones are stiffer due to the decreased distance from coil to surround (less flex). There is a reason that Fender's most popular bass amps are 4-10.
A pair of twelves works well with a guitar because it has a lower resonance which gives it more low end "thump".

That's my thoughts on it. Others may disagree.

LeeMo

[Luthierwnc]

9pins said the the most important thing. You have to look at anecdotal information for practical applications. Some circuits are just born for the different configurations. For instance, the low-power twin and the 5E6-A Bassman (got one on the bench right now) are identical amps except for the speakers and I'd take the 4X10 every time. EL84s and EL34s seem to need 12s. Tube rectifiers tend towards 10s because their focus makes up a little for the sag. I like 12s with a Strat but Dumbles are made for 12s and that is the hardest guitar to make sound right. I haven't heard a lot of closed-back 4X10s which is probably because they sound better with an open back. 12s can sound good either way.

Right now I'm trying to decide what to do with a basket-case Ampeg Gemini II. The cab is toast and I already have a 1X15 Pro so I'm toying with the idea of making a separate head and 4X10 cab. Don't think that one would work with 12s.

Without rambling too much, you really need to narrow-down your choices by looking at the tubes, circuits and guitars you are mostly likely to use. If you go in thinking of the percentages of sounding great with anything, you will be at the mercy of the factors (and dozens like them) I mentioned above. sh

[ryanm74]

I probably should have talked about what I wanted to do. I have a super reverb that someone converted to 2x12, and I am replacing the speakers. I started wondering about going back to the original 4x10 configuration. I have ended up putting it in a bandmaster reverb cabinet for the time being, so that I can use different cabinets until I find the right setup. I think I am going to pick up a 4x10 open back cabinet, so that it is easier to carry around but still has the super reverb vibe going on. Those old fender combos sound great, but so heavy!

[renshen1957]

I probably should have talked about what I wanted to do. I have a super reverb that someone converted to 2x12, and I am replacing the speakers. I started wondering about going back to the original 4x10 configuration. I have ended up putting it in a bandmaster reverb cabinet for the time being, so that I can use different cabinets until I find the right setup. I think I am going to pick up a 4x10 open back cabinet, so that it is easier to carry around but still has the super reverb vibe going on. Those old fender combos sound great, but so heavy!

Hi,

The old Tweed 4X10 Bassman's combo successor was the Black Face Super Reverb. In General the difference is where the volume loss occurs in the preamp from the tone stack placement and a few component values. Yes, the SR has 6l6GCs in place of the industrial version of the 6L6G (5881) and an effects channel (reverb) in addition.

I am all for the open back cab and separate head, combos are very hard on tubes. I would recommend I thick piece of foam rubber if you are going to stack the piggy-back style, better yet was the old Vox style separate stand for the head (think Beatles) either method somewhat isolates the amplifier from the speaker vibration.

Best Regards,

Steve

[rdjones]

The old Tweed 4X10 Bassman's combo successor was the Black Face Super Reverb.

I see the lineage like this:
5F6 Tweed Bassman -> 6G12 Brown Concert -> AA763 Blackface Concert -> AB763 Blackface Super Reverb

rd

[9pins]

You can also mix speakers, a couple 10's and a 12, its a preference thing.
I like 12's, but I play clean (er) and am careful with coupling cap values through the amp to reduce "flabbing out".

[Luthierwnc]

I've had a couple Super Reverbs. One was an early Silverface with a typical screwed-in baffle. The other was a 1980 where the baffle was glued into dados in the exterior cab and the grill was velcroed on. The only way to get it out was to destroy it (well, mine was destroyed anyway). The earlier ones would be much easier to mix and match.

It may not be relevant but I ended-up chiseling the particle board baffle out of the dado, setting the edge of a new 1/2" BB baffle in one side and "persuading" the other side with a pair of pipe clamps and a mallet. 1/4" shims glued behind that held it tight. If I had it to do over, I would have furr-ed the old dado, put screw cleats just behind it and attached the new baffle like usual.

If you like the head/cab arrangement, the old 4X10 cab will still work fine -- especially with the custom top-port sh

[Gibsonman63]

Not to hijack the thread, just a brief tangent.

I restored a water damaged Fender a couple of years back with the dado-ed baffle panel. I used a saws-all on mine, then pried out the loose pieces that would come out, sanded, filled with Durham's, then sanded again. Not as much work as it sounds, actually. The hard part was getting the inside finish to match what a BF cabinet should look like. I went back with the strips glued to the cabinet and screwed the new baffle in from the back like the Blackface Fenders.

I don't really have a preference on 4x10 vs 2x12 vs open back vs closed back. Super Reverbs sound great to me when they are dialed in. A good Twin is nice. I have had a few closed back 2x12 Fender speaker cabinets and they all sounded nice. I am gigging now with a closed back Marshall cabinet with heritage 30s.

IMHO, the tilt back legs on the Super Reverbs is a nice feature. If you can get far enough in front of it where you aren't blasting yourself, it fills the room nicely without beaming into your audience.

[TUBEDUDE]

The smallish clubs I most often played, (when carting around a Super), benefitted most with the tilt back legs deployed and the amp facing the rear wall. The signal bounces off the rear wall and ceiling, dispersing nicely through the room. Warning ,the drummer will most likely not see the beauty of it.