Bass amps for Live work

[Chili]

I'm pretty sure the cab is 8 ohm, but that's okay. I'll build a 1x15 cab and use an 8 ohm speaker to go in parallel.

I read on the internet (so it must be true) where there is differing schools on thought about mixing cabs and speaker arrangements and phase issues and all the horrible things that can go wrong, but I'm not worried about that stuff. I think building a cab would be a lot of fun. Ported, folding horn, etc. oh, the possibilities.

Plus Eminence gives you the ideal cab volume for each speaker, so half the homework is done.

 

[CoolCat]

I like that mute option for a tuner out with the HA4000, pretty cool.

 

[Greg_L]

I'm pretty sure the cab is 8 ohm, but that's okay. I'll build a 1x15 cab and use an 8 ohm speaker to go in parallel.

I read on the internet (so it must be true) where there is differing schools on thought about mixing cabs and speaker arrangements and phase issues and all the horrible things that can go wrong, but I'm not worried about that stuff. I think building a cab would be a lot of fun. Ported, folding horn, etc. oh, the possibilities.

Plus Eminence gives you the ideal cab volume for each speaker, so half the homework is done.

I used to play with a guy that had an ancient Acoustic (the brand) bass cab that was literally almost the size of a refrigerator. It had four 15's in it pointing backwards into these baffles that then "focused" the sound out this wide horn thing in the front. It sounded like a friggin tugboat horn. Really cool piece of quirky gear. Totally unusable though. I think it might have actually been for a PA system.

 

[Lt. Bob]

I used to play with a guy that had an ancient Acoustic (the brand) bass cab that was literally almost the size of a refrigerator. It had four 15's in it pointing backwards into these baffles that then "focused" the sound out this wide horn thing in the front. It sounded like a friggin tugboat horn. Really cool piece of quirky gear. Totally unusable though. I think it might have actually been for a PA system.

if I'm right couldn't you see the backs of the drivers when you looked at the cab?

If so that's a PA bass cab.
They were actually using those at the venue I played last Nov. when I went back to Baton Rouge.

 

[Greg_L]

if I'm right couldn't you see the backs of the drivers when you looked at the cab?

If so that's a PA bass cab.
They were actually using those at the venue I played last Nov. when I went back to Baton Rouge.

I don't remember seeing the backs of the speakers as his grill cloth was in good shape, but yeah I suppose in the right light you could see them. The front was solid like an 8x10 but with a wide horn going across the middle. And it had dolly wheels on it, although those may have been added later. It probably was indeed a PA cab. It looked like something you'd see at music venue. He played bass through it sometimes just for shock factor.

 

[Chili]

Like this??

 

[Greg_L]

Sort of, but not really. These speakers definitely faced backwards and there was a big horn in the middle. It was also wider than that. But it was in that style with the blue logo bar across the top.

 

[CoolCat]

Dumb question time....

if you have the amp with a 8ohm speaker, and later build that 15" cab w/ 8ohm speaker, do you plug the cable from the other amp out jack to the 2nd 8ohm speaker? or does one spekaer connect to the other speaker?

 

[Greg_L]

Dumb question time....

if you have the amp with a 8ohm speaker, and later build that 15" cab w/ 8ohm speaker, do you plug the cable from the other amp out jack to the 2nd 8ohm speaker? or does one spekaer connect to the other speaker?

It can work either way depending on how it's wired up. I think it's safest to just run a speaker cable from the amp to each cab.

 

[Chili]

Dumb question time....

if you have the amp with a 8ohm speaker, and later build that 15" cab w/ 8ohm speaker, do you plug the cable from the other amp out jack to the 2nd 8ohm speaker? or does one spekaer connect to the other speaker?

Either way will work. The two plugs on the back of the amp are in parallel, two 8-ohm speakers will be 4 ohm to the amp. If you daisy chain from one speaker to the next, you have to be sure they are wired in parallel, otherwise you would be doubling the impedance to 16-ohm rather than lowering it to 4 ohm.

 

[Lt. Bob]

Either way will work. The two plugs on the back of the amp are in parallel, two 8-ohm speakers will be 4 ohm to the amp. If you daisy chain from one speaker to the next, you have to be sure they are wired in parallel, otherwise you would be doubling the impedance to 16-ohm rather than lowering it to 4 ohm.

it'd really be pretty hard to daisy chain a couple of speakers in series. There'd have to be some sort of switching jack in one of the cabs or an actual switch to do that.

 

[CoolCat]

Either way will work. The two plugs on the back of the amp are in parallel, two 8-ohm speakers will be 4 ohm to the amp.

easy enough.

 

[CoolCat]

for what its worth...the band said the pf350 into a 1x15 8ohm isnt loud enough for them.
so back to the Rumble100watt and line out>400watt pa head>1x15.
strange playing the setup alone it sounded so loud and clear, beautiful tones.
these guys play pretty loud, so I guess until I can afford a 500watt or more head and 4ohm setup, I'll wait.
this result does align to whats been repeated about amp sizes and cabs.

 

[Lt. Bob]

yeah .... you really need 500 watts. I know that sounds daft but bass freqs take a lotta juice.
For one thing they have to physically move the speaker cones 20 times further than a guitar speaker moves ...... even more at some comparative freqs. It's just like moving a larger load in a car ...... needs more horsepower.

Did you see this I posted earlier?
$375 for 500 watts. Here's a review.
Overton Flyweight 500 Micro Amp Review - Premier Guitar

 

[Chili]

Just picked up the Hartke HA4000 and a 4x10 cab. Cool.

The guy didn't have a bass to try it out with so we used one of his guitars. It sounded good, no distortion, buzzing, etc. I'll try it out tomorrow with my bass. The clip light came on a couple of times with the guitar, so something I'll have to watch for.

Plus, he was willing to come off the price by $50. I like that.

 

[CoolCat]

Alright Chili.... damn good price, thats like the cab for free!

Lt.Bob, looks like I'll have to gather another $100 and a 100 watts! and another cab! daaaaaang I was just trying to help the bass player get a rig going! lol

 

[Lt. Bob]

Just picked up the Hartke HA4000 and a 4x10 cab. Cool.

The guy didn't have a bass to try it out with so we used one of his guitars. It sounded good, no distortion, buzzing, etc. I'll try it out tomorrow with my bass. The clip light came on a couple of times with the guitar, so something I'll have to watch for.

Plus, he was willing to come off the price by $50. I like that.

great ..... that's a killer deal methinks!
You're gonna want another cab to get that impedance down to 4 ohms so you may as well start looking at what design you'll go for.

And I've always built my own cabs. In fact .... I have a couple in the planning stage right now. I used to build my own PA cabs too .... voice of the theater type stuff.
It is fun.

Next cab I build's gonna have some el-wire on it instead of piping.

 

[Chili]

Alright Chili.... damn good price, thats like the cab for free!

great ..... that's a killer deal methinks! .

Cool. Glad to hear it. Avoid the buyer's remorse syndrome. I think I'm gonna like it.

So Steve, about this cab building thing.... I think I might have to start another thread...

I've got a lot of MDF laying around. Have you used that stuff with good results?? Or should I be looking at plywood??

 

[jonny deep]

Stupid question: does the bass amp you bought put different power out depending on impedance? My guitar amp puts out 15W regardless of whether you plug into the 8 or 16 ohm tap (according to the spec sheet) - is this different in bass amps, or is it particular to some amps in general?

 

[Greg_L]

Stupid question: does the bass amp you bought put different power out depending on impedance? My guitar amp puts out 15W regardless of whether you plug into the 8 or 16 ohm tap (according to the spec sheet) - is this different in bass amps, or is it particular to some amps in general?

Very generally speaking, I think solid state amps don't care what kind of speaker load you put on them. Bass amps are often solid-state or a hybrid with a tube pre-amp stage. The power section is SS. If the amp is rated for say 400 watts @ 4ohm load, if you connect it to an 8 ohm cab, you're only gonna get 200 watts out of it. 200 watts of bass power is not very much, so adding another 8 ohm cab will make the amp "see" 4 ohms and the power output will come up. Or something like that. I don't understand the electronics behind it. That's just how I've always thought of it.