Wiring a 2x12" bass cabinet, need speaker selection hel

[holmburgers]

Howdy,

I'm brand new here, so hello to everyone, and although I'm a subscriber to the magazine, I've never been on the boards. Seems like a great place!

Anyways, so I've been playing bass thru a silverface Bassman 50 (4 ohms) and an older Ampeg 4x12" (8 ohms, so not 100% ideal). Everything is great with this rig soundwise, but with the purchase of a newer/smaller car, this cabinet is too much to gig with. I've bought a Sunn 2x12" PA cabinet with the idea of swapping out the speakers. As it is (16 ohms, PA speakers), it sounds like junk with the 4 ohm bassman, but the cabinet is really solid. It does have a tweeter that I will not wire in, but I can either leave it in place or take it out to act as a port. Not sure which is preferable.

My goal is to get a great sounding cabinet with plenty of guts, punch & rumble. I'm familiar with wiring in series/parallel/parallel-series and this shouldn't be a problem, I just want the best combination of sound & affordability/availability that will result in a 4 ohm 2x12" bass cabinet.

Basically I don't know what speakers to consider. There are so many out there and it's just difficult to narrow it down. I'd say that $150 for both speakers would be the upper limit of my budget (update.... disregard budget constraints). I'm not against mixing 2 speaker types, if that's recommended.

So, if you're willing, hold my hand and walk me down this unfamiliar path... strictly platonic of course.


Cheers!

[Nate Dort]

With a $150 budget, Eminence is probably your best bet. You can get a pair of these for about $150 shipped.

[holmburgers]

Thanks for the reply.

I'm mainly looking for used speakers and vintage stuff, as you can nearly always get more bang for your buck.

And actually, let's forget the $150 budget for the time being. Sky's the limit.....

What are some of the "classic" bass speakers?

[norton]

don't dump on the eminince too quickly.. they make great sounding speakers.

If you're playing through a bassman head, most likely you'll be happiest with relatively loud (more efficient speakers). Which is something eminence excels at. Check out their website for all the details.

This might be a bit out of the box, but I've had really good luck with running bass through an Eminence cannabis rex and wizard speaker. These are designed for guitar, but the crex can handle all the bass you can throw at it.

If I were going for a bass only 2x12 cab, i'd keep the crex, and go with a speaker that has a little more bass than the wizard...

Used and vintage speakers are a complete crapshoot. Given how delicate speakers are and that you're going to be stressing the crap out of them by running bass through them.. you might want to think about building in the cost of a re-cone on anything vintage that you buy.

Hopefully it won't be necessary..... but it's pretty likely to be the case.

[radical recording]

Eminence has a 12-inch speaker called the Kappa 12 that I've been using for years in a 2-12 bass cab. 450 watts and sounds great.

http://www.pulseonline.com/eminence15.htm

[holmburgers]

Cool, I'll look into all of the above mentioned speakers.

Is there much of an advantage to alnico magnets with bass? Or is that more of a guitar thing? I'd say that what I'm going for is more of a vintage sound, but I guess that's gonna be due to the amp more than the speakers.

Thanks for the responses, keep 'em coming if you've got anymore!

[norton]

Your speakers have a HUGE influence over what your amp will sound like. HUGE!

Alnico vs. ceramic in the same voice coil/frame etc.. will have a differenece, but that difference is mainly in how the speaker breaks up. Generally, alnico magnets break up a little smoother and softer.

In a bass speaker, you're going to be looking at ceramic and neodymium magnets. Alnico's generaly too expensive and not efficient/powerful enough for bass speakers.

Fender used whatever speaker they could get their hands on for the cheapest price. So some of their bassman cab's had jensen's some had oxford's some had cts speakers.. They all sound different.

If you're looking to keep up with a band, I'd recommend the most sensitive/efficient driver's you could find that sound good.

A bass guitar working a bassman amp is a cool sound. But it's hard to get enough impact out of that setup without some more juice. A super lively speaker might make the difference between a setup that works and one that requires a p.a. to be useful.

[holmburgers]

Thanks norton,

I think you're absolutely right. Subtracting two speakers has made me worry a bit about my volume. Rarely is my 4x12" not loud enough, but around 7 on the dial it doesn't get louder, it just starts breaking up. So as it is, it's perfect, but indeed I need to be looking to optimize the 2 speakers I'll be left with. Fortunately I'll be optimizing my ohm load as well, which should give me a bit of a boost to counteract any drop in dB from less speakers.

So, efficiency is stated as sensitivity, right? Basically the dB/watts?? I'll begin to hunt for the loudest mother's out there....

Also, good to know about the alnico. The prices are crazy, so that's welcome news...

One more thing, what difference does magnet size make? Some of those eminence speakers have 4oz. magnets and then they go up to 45oz.! That seems like a crazy jump, yet the specs aren't all that different.

[Nate Dort]

One more thing, what difference does magnet size make? Some of those eminence speakers have 4oz. magnets and then they go up to 45oz.! That seems like a crazy jump, yet the specs aren't all that different.

I bet 4oz is a typo.

[Jed]

You can, and should, get more scientific if you want to end up with a system that performs the way you want it to.

Sensitivity is part of the equation, but it is only part of it. You also need to know the volume of air in that cabinet and how that is going to affect the speakers you choose.

A different way to approach this situation would be to measure the cabinet carefully to understand the air volume you will be working with. Now you have some choices: do you use the cabinet sealed, or do you vent it to "tune" it to a specific frequency? Using 2 speakers in a small cabinet can mean that you end up with a big frequency bump in the 100-200+hz area, but sometimes very fast roll off below 100hz. That means you are getting almost none of the fundamental of the bass.

A few months back I modified an old 2x15 bassman cabinet to be a 1x15 with a vent. (I play bass through a '68 Dual Showman head --~80 watts). I used WinISD to figure out the best speaker for the situation (http://www.linearteam.dk/default.aspx?pageid=winisd). Running a 2x15 setup didn't have enough air volume to get any low out of the cab. Creating a specific sized vent allowed me to get the cabinet to produce good bass down to 45hz. I decided to go that route and live with a 3db loss in volume. Now the speaker and port move so much air that I can't even put the grill back on (the cloth vibrates too loudly from the massive air flow coming out of the port). It has way more thump and low bass than before, but it is slightly quieter.

You are going to want to do a little reading on Thiele/Small parameters http://en.wikipedia.org/wiki/Thiele/Small, figure your cabinet volume, and then decide what kind of frequency response/loudness you want. With a small cabinet these two parameters are at odds with each other.

[holmburgers]

Hey,

Thanks a lot for the informed response! These are things I hadn't considered very much.

I think you're absolutely right, I need to know what's going on with the resonance & volume as I don't wanna end up with a dud. I'll start researching....

thanks again