Special Cabinet

[Eric Christian]

So yeah over the years I've built several 4x12 cabinets for people. The last one I built got stolen out of my truck but thats another story. Anyway, so with the low tuned guitars I found the 6505 cabinets I had for a couple years couldn't hack it when the fuzz and octave pedals kicked in. So I got rid of them and I was gonna get a Mesa oversized but then I thought why don't I just build another couple 4x12 cabinets myself and use either some 100 watt Celestions or perhaps some Peavey Black Widows. Then I remembered this idea I had a long time ago which was building a nice solid 4x12 sized cabinet but just put one monster 12 inch speaker smack dab in the center? Bottom line I'm looking for that deep bottom end without losing the mids and highs. I'm not big into math and formulas regarding the science behind speakers and cabinet volume but anyone think this might be a good idea or just plain stupid?

 

[AwDeOh]

With 8 strings becoming more common these days, I don't think it'll be long before people start going into bass territory with amps. My first guess would be that the next logical step from 4x12 for ERG players is something like a 1x15 bottom, with a 2x12 on top - or even putting them in the same box if there's enough room with whatever baffling you want to build in.

This thread reminds me of how nice it is not to be doing live sound anymore and having to remember all the acoustic engineering crap from my course.

 

[Yo_Wattup]

For more bottom end all you need to do is tune your cabinets, and you do this by putting what we call ports in them. Lemme explain ports for you.

You ever wonder why bass cabs have the section (usually at the bottom) cut out? Visual aid:

Thats a port, and how far the cutout goes into the cab determines the frequency the cab is tuned to. Ports can be circular too, which is easier for DIY cab builders because we can just use PVC pipe for ports.

The reason why guitar cabs dont have this (cabs with ports are called vented cabs, as opposed to sealed cabs), is that this is only really effective for frequencies below 100hz. Such frequencies are usually undesriable to guitarists.

Vented enclosures tend to have lower frequency response, a trade off is they require a little (not much) more power to get as loud as sealed cabs... another reason guitarists love sealed cabs.

I would recommend downloading this program LinearTeam (WinISD)

Basically you enter the specs of your speaker and the size of your cab and you can see what the low end response is. Do it again, but this time simulate a vented cab and see what the frequency curve looks like. (It'll have a shitload more bass but it wont be as loud)

Alternatively, if you cant find the Thiele/Small parameters for your speaker, just drill some holes (at least 4 reasonably sized ones, you dont want the air in the ports travelling too fast other wise you get this nasty buffeting sound) into your cab, and get a few lengths of pipe, and try each length to see what yields you the better bass response. Dont go too low though coz this can fry the voice coil of your speakers...

That is a VASTLY compressed and brief explanation of ports and how you can use them to your advantage... google for more info

I have a thread over at talkbass.com where we discuss cab dimensions.. give it a read.. and try to ignore the haters.... The user CL400Peavey seems to be the only one intelligent enough to take part in the conversation So I want to build a BIG cab... - TalkBass Forums

 

[Eric Christian]

Yeah ISP Technologies make some cabinets that are different than standard. I kinda wanted to stay away from 15 inch speakers but that may be what I need is one 15 and one 12 inch speaker with a filter cap. I found a pretty good websites on cabinets as well.

Speaker Box Volume Calculator / Designer

Speaker Enclosure Volume Calculator

 

[mcleanab]

Yeah ISP Technologies make some cabinets that are different than standard. I kinda wanted to stay away from 15 inch speakers but that may be what I need is one 15 and one 12 inch speaker with a filter cap.

Beat me to the punch... Another thought might be to entertain what the Theta Combo does... runs a 1x12 and a 1x12 subwoofer; two different power amps and a crossover...

http://www.isptechnologies.com/portfolio/theta-combo-amplifier/

Isn't there a 4x12 Dimebag cabinet that is similar to the ISP Vector cab? Has a 15 inch speaker as well?

 

[Vostre Roy]

Isn't there a 4x12 Dimebag cabinet that is similar to the ISP Vector cab? Has a 15 inch speaker as well?

I think you're thinking about the Randall RS125CX, wich is a 2x12" + 1x15" cab

 

[mcleanab]

I think you're thinking about the Randall RS125CX, wich is a 2x12" + 1x15" cab

Yup... that would be it!

(and I take great issue with your signature, sir! )

 

[Vostre Roy]

(and I take great issue with your signature, sir! )

In all fairness, I do own SS amps

Back on topic, I've been thinking about building a similar cab to the RS125 for a while, always posponed it but I think it would be a neat cab for stoner/doom metal as I expect the 15" speaker to be a little on the "woofy" side, but I can be wrong as I never experienced any.

One day I'll bring that project to live, but if you do before me, please come back with your results

 

[mcleanab]

In all fairness, I do own SS amps

Back on topic, I've been thinking about building a similar cab to the RS125 for a while, always posponed it but I think it would be a neat cab for stoner/doom metal as I expect the 15" speaker to be a little on the "woofy" side, but I can be wrong as I never experienced any.

One day I'll bring that project to live, but if you do before me, please come back with your results

All in good fun...

Yes, please keep us posted on your results. The ISP Theta Combo is such an interesting beast with the sub woofer, and I've not had the pleasure of hearing in person the Theta Vector cab or the Randall RS125CX, but can imagine the possibilities.

 

[JedPan142]

Would anyone be able to give me any help, I am trying to take my B-52 AT212 Combo amp and separate it into a 2x12 and the power amp. I have some ideas on what i want the cab and amp casing to look like, but I don't know how to do it myself or where I could find a place to order the prestained woods.

Was thinking a blue stained burled maybe not one that complex of a finish, maybe just completely stained.

like this, and then put black elbow pieces and grill cloth on the 2x12 and do the whole see through face plate on my amp so you can see the tubes. Any advice would be great.

 

[Djentliman]

necrobump much.

 

[JedPan142]

What even is that?