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Ampeg amp Q - with pics

A

AlstottMVP2

May 9, 2007
253
0
#1
I own the Ampeg B2RE bass amp.

1.jpg


According to the website, it is:
450W @ 4 ohms, 250W @ 8 ohms

I have two speakers I would like to run it to.

The first is a Hartke 4x10 speaker.

2.gif


I think it's rated at 8 ohm, as listed on the back.
3.jpg



The other amp is the Ampeg 1x15 with wheels:
5.jpg


No listing of ohms on the back, but it looks like this:

4.jpg


I have bought two of these, and they broke each time. Maybe i did it, wiring it wrong. The guy at the store told me to just plug it in, no worry about ohmage.

BUT - the B2Re has TWO speaker outputs, and I ran two cables form it, one to each speaker. Someone told me I SHOULD have wired 1 speaker cable to the hartke, then
another wire from the hartker, into the Ampeg. Is this true? Does it matter?

Please help me. I'm getting it back from the shop early next week, and I realllly don't want to plug it back in and destory it (a 3rd time). They said the board needed soldered (it's under warranty).

Thanks!
 
#2
If the "these" that you broke two of was the B2RE, then what probably happened was the Ampeg 115 is rated 4 ohms, which in combination with the 8 ohm cab makes a 2.67 ohm load. And your amp cannot handle a 2.67 ohm load without burning out.

Maybe you can swap an 8 ohm cone into that cab. That would bring the combined load to 4 ohms, which your amp can handle.
 
#4
You can run one 4 ohm speaker, OR two 8 ohm speakers, OR four 16 ohm speakers, etc.

You can NOT run one 8 ohm AND one 4 ohm, or more than two 8 ohm speakers, etc. That ends up under 4 ohms

How you hook them up is not that important, one wire to each is fine, and a wire to the first and from that another to the second is usually fine also. A few speakers can be "split" into 2 sub-systems by plugging into extra jacks, in which case follow the directions........

The manuals used to have a neat little table of what you could use and be OK for any given minimum impedance. You might look for that.

It had hookup information also........... maybe the Loud folks cut that back? Could be one reason their stock was at $2.86 today, but $15 a couple years ago
 
#5
bongomania said:
If the "these" that you broke two of was the B2RE, then what probably happened was the Ampeg 115 is rated 4 ohms, which in combination with the 8 ohm cab makes a 2.67 ohm load. And your amp cannot handle a 2.67 ohm load without burning out.

Maybe you can swap an 8 ohm cone into that cab. That would bring the combined load to 4 ohms, which your amp can handle.
Click to expand...

Okay. For a short-term solution - I could just run the 4x10 and keep the 1x15 for a home amp?

And just so I know - please break this down for me - For my Ampeg amp that says "8 ohms at 450 watts", I should only buy a 15-inch bass cabinet rated at 8 OHMS?

Forgive my ignorance on this. thanks!
 
#10
AlstottMVP2 said:
Okay. For a short-term solution - I could just run the 4x10 and keep the 1x15 for a home amp?

And just so I know - please break this down for me - For my Ampeg amp that says "8 ohms at 450 watts", I should only buy a 15-inch bass cabinet rated at 8 OHMS?
Click to expand...

You can run either one by itself. You can run the Hartke with another 8 ohm cab. You cannot run the 115 with any other cab. You don't need to use an 8 ohm cab with that amp, but whatever cab (or cab combination) you use has to be at least 4 ohms total load. Read the ohms FAQ.
 
#11
thanks - this is VERY helpful.

I remember that I blew up the first one when I was using it with the 8 ohm hartke, and another piece of junk 2x15 backline speaker.

I blew up the second one using (what must be a) 4 ohm 1x15 ampeg and an 8 ohm 4x15 hartke.

I think that makes sense to me. (kicking myself, but both were covered).

I will just use the 1x15 ampeg for now with it. Heck, it has wheels :)

The next question is this---- how can I be SURE the 1x15 Ampeg is only rated 4 ohms, and can anyone recommend a 2x10 ampeg speaker cab that will look good with it, and fit the ohms? thanks!!!!!!
 
#12
AlstottMVP2 said:
The next question is this---- how can I be SURE the 1x15 Ampeg is only rated 4 ohms, and can anyone recommend a 2x10 ampeg speaker cab that will look good with it, and fit the ohms? thanks!!!!!!
Click to expand...

Do you have access to an ohm meter / DVM? If not, you can get decent ones for under $20, some under $10. Always good to have around for testing. Plug a cable into the back of the cabinet and hook the ohm meter to the other side. A 4 ohm cabinet will likely have a resistance somewhere between 2.5 and 3.5 ohms. If it's an 8 ohm cabinet the resistance will probably be between 5 and 7 ohms. These are just general guidelines, but you should be able to tell the difference between a 4 and 8 ohm cabinet this way.
 
#13
AlstottMVP2 said:
thanks - this is VERY helpful.

I remember that I blew up the first one when I was using it with the 8 ohm hartke, and another piece of junk 2x15 backline speaker.

I blew up the second one using (what must be a) 4 ohm 1x15 ampeg and an 8 ohm 4x15 hartke.

I think that makes sense to me. (kicking myself, but both were covered).

I will just use the 1x15 ampeg for now with it. Heck, it has wheels :)

The next question is this---- how can I be SURE the 1x15 Ampeg is only rated 4 ohms, and can anyone recommend a 2x10 ampeg speaker cab that will look good with it, and fit the ohms? thanks!!!!!!
Click to expand...

You could always look at the speaker. The impedance will be on there. Most likely you would have to take the speaker out as it is probably on the back of the speaker. not a lot of fun but you'll know.
 
#14
gerryjazzman said:
Do you have access to an ohm meter / DVM? If not, you can get decent ones for under $20, some under $10. Always good to have around for testing. Plug a cable into the back of the cabinet and hook the ohm meter to the other side. A 4 ohm cabinet will likely have a resistance somewhere between 2.5 and 3.5 ohms. If it's an 8 ohm cabinet the resistance will probably be between 5 and 7 ohms. These are just general guidelines, but you should be able to tell the difference between a 4 and 8 ohm cabinet this way.
Click to expand...

good call. i just picked one up on ebay.
 
#15
BTW, the current B-115E cab is rated 8 ohms..... I thought so and the Loud site confirmed it.

The backplate SHOULD have had a label on it..........

If the Hartke cab is 8 ohms also,you should have been fine with that........ but then your description of the repair does not scream "blown amp", instead you described it as "they said board needed soldered"......
That would have nothing much to do with the speakers, which are not related to bad solder joints on a board.
 

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