1-12" vs 2-12" vs 2-10" Need some insight

[markmalin]

Hi Guys,

I just got back from Dave's Guitar in LaCrosse WI where I took my d-clone to try it with some different speaker cabinets. I tried this closed backed "divide by 13" cabinet with 2-12" Celestion Greenbacks (G12M, I think) and it blew me away. The tone and responsiveness of my amp COMPLETELY came alive.

I'm currently constructing another combo cabinet for my chassis which, unfortunatly is almost done. The divide by 13 was made of baltic birch, my combo is pine and obviously can't have a closed back. I'd like to try the Celestion greenback in hopes of reproducing some of the "goodness" of that div. by 13. I can't fit 2 12" speakers in my cab, though. How would 2 10"'s compare? Fuller than 1 12"?? How about 1 12" and 1 10"?? Anyone have any advice or thoughts on this?

Thanks,
Mark.

PS - I relalise we're talking closed vs mostly open back and different cabinet woods, but all things being equal, what say you about the speaker size combinations above??

[hairyandy]

I've always wanted to try a 1-12" and 1-10" combo. Celestion now makes a Greenback 10" and a Gold Alnico 10" so maybe one of those would be cool with a Greenback 12"? I've heard the Greenback 10's in a 65 Soho combo and they were great...

The closed vs. open thing is a huge part of the sound though.

Andy

[markmalin]

I've always wanted to try a 1-12" and 1-10" combo. Celestion now makes a Greenback 10" and a Gold Alnico 10" so maybe one of those would be cool with a Greenback 12"? I've heard the Greenback 10's in a 65 Soho combo and they were great...

The closed vs. open thing is a huge part of the sound though.

Andy

Thanks for the input, Andy. Point taken on the closed/vs open back. I know that has much to do with it.

You know... I just remeasured my cabinet and I can't shoehorn a 10 AND a 12 in there So I'm stuck at this point with either 1 12" or 2 10"'s. The green backs only come in up to 25W, so if I go with 1 12" I can't do a Greenback.

So what are peoples' thoughts re 1 12 vs 2 10's? Would 2 10's tend to move more air and be fuller due to the increased area combining the two?

Mark.

[CapnCrunch]

Here's a link to to Q&A from Weber. I know folks here still have their issues with Ted, but there is a lot of great info on his site. Look at it if you want. www.webervst.com/sptalk.html There used to be a specific section dealing with the differences between speaker sizes and the math behind it. i.e. 2x10' will have significantly greater bass response then a 1x12. It has to do with speaker area and the amount of air the speakers can move. I don't see that discussion in the Q&A anymore, but there is still some discussion on closed back v. open back cabs and cab sizes that you may find useful. Take a look at why some speakers sound good in sealed cabs and other's don't. This why (to my ear) Greenbacks don't sound so good in open back cabs:

"When a person designs a speaker, one of the considerations is how much the cone will move and the subsequent loudness for a given amount of power driving it. If the designer uses a loose spider and fairly flexible surround on the cone, the voice coil will have an easier time moving the cone and the speaker will be loud with a small amount of power. The problem with a loose spider and surround is that as the power is increased, it takes the cone to its mechanical limit of movement and it gets harsh. This is an underdamped system and can also sound ringy. If you put this speaker in a sealed or closed back cabinet, the air that is trapped in the cabinet acts as a spring or big balloon that the back of the cone pushes against. This air mass helps control the movement of the cone and also affects the damping of the system, making the speaker sound more in control. A designer who uses a big magnet, tight surround and tight spider is designing for a low system Q, good damping, and good transient response. In other words, when you hit it with a sharp attack note, it responds and then stops very quickly rather than ringing on and on. This speaker would work well in an open back. However, in a sealed or closed back, the air mass spring we discussed earlier would add to the damping, potentially causing the speaker to be overdamped, compressed, and lifeless. It's a difficult design task to design a speaker that is a good compromise for all shapes, sizes and types of cabinets".