Any Advice Please. My amp cuts out!

[i_play_ibanez]

Hi I am new to the forum. I figured I would get some extra advice about my situation. I have 2 4X10 MesaBoogie Road Ready cabinets and a Mesa Titan V-12 amp. I bought the cabinets separetely at different times and some how ended up with one cab being 4 ohms and the other being 8 ohms. Both cabs were the same but we did not realize the speakers were different ohms until my amp started overheating on stage. So we swapped the speakers out of one of the cabs with 8 ohm speakers. With all hopes that that fixed my problem it didn't...so I was using two 4X10 cabs all with 8 ohms speakers in it and my amp still overheats and cuts out on stage using both the cabinets. I tried using different Mesa Titan V-12's that the guitar shop owner had and it still did not solve my problem. If I use only one of my 8 ohm speaker cabinets with my amp I don't have any fear or problems with my amp overheating and cutting out during a live situation. I really like the looks and sound of both of the cabs together. I talked to my guitar guy and he said my best bet would be to get a voltage regulator...another person told me to get an 8X10 speaker cabinet and use it live the amp does not have to split the signal like it does with two 4X10 cabs which means it won't have to work as hard. I am really curious on what everyone's opinion is on this. Should I go the voltage regulator route or should I get the 8X10. I don't want to spend the extra cash unless it solves my problem. Please any advice or opinions would be great appreciated.

 

[Nick Kay]

My first instinct would be to avoid buying anything else, because more crap to go wrong will not fix your problem.

First off, when you're using two 4ohm cabs or an 8ohm cab and a 4ohm cab, you need to switch the Speaker Impedance switch to the down (2ohm) position. The V12 goes into protection mode here and there if you don't. Conversely, make sure the switch is in the 8/4ohm position if your load is 4ohms or greater. I don't know if having the switch in the wrong position will damage anything, but it's better to be safe than sorry.

Furthermore, the V12 is fan-cooled. If you're having any sort of problems with overheating, the first thing you should do is check to make sure the fan is clear of any obstructions, has plenty of room around it to move air, and isn't clogged with dust and grime. Even if everything looks clean, give the vents a few blasts with some compressed air, just to be safe.

All that being said, if you're using two 4x10 cabs powered by the monstrous Titan V12 and it's going into thermal protection, you MIGHT just be playing a bit too loud, dude.

 

[konodl18]

I'm not familiar with Mesa gear, but the first thing I noticed is that loading a 4x10 cab with all 8 ohm speakers does not necessarily give you an 8 ohm cab. Depending on how the speakers are wired internally you may end up with anywhere from a 2 ohm cab to a 32 ohm cab. Series vs. Parallel wiring changes the load you amp actually sees. Thats the first thing I would check.

Hope this helps,
Derek

 

[JackANSI]

I'm not familiar with Mesa gear, but the first thing I noticed is that loading a 4x10 cab with all 8 ohm speakers does not necessarily give you an 8 ohm cab. Depending on how the speakers are wired internally you may end up with anywhere from a 2 ohm cab to a 32 ohm cab. Series vs. Parallel wiring changes the load you amp actually sees. Thats the first thing I would check.

Hope this helps,
Derek

+1 get out your ohm meter and check to see if its 8ohm +/- 2ohms

And use this to figure out how to connect them:

http://www.colomar.com/Shavano/impedance_proc.php


Usually if you have 4 identical speakers in 8 ohm, to get an 8 ohm cab you need to make two series strings of 2, then connect that in parallel. That way when 1 speaker blows your amp gets a 16 ohm load and it don't fry more speakers since it'll be making less power.

If you wire it the other way (2 parallel strings wired in series) and 1 speaker blows your cab goes from 8 ohms to 5.33ohms. Which means your amp makes more power, and more speakers could blow.

 

[konodl18]

I_PLAY, did you get the issue sorted out?

 

[i_play_ibanez]

I appreciate alllll the advice everyone has given me. The guy I do all my buying from is a certified Mesa Dealer. He tested the ohms on the cabinet and everything. It wasn't that. I even made sure the impedance switch was on the right ohms. I ONLY have this problem in live situations. I can use both my cabs at a practice space and be totally fine though only on one occasion it has cut out. We thought maybe it could be something with the amp but I tried different Mesa V-12's from the shop. None of these amps have been sitting in the guitar shop for very long. My amp is not dusty or dirty. I never play that loud live. I usually have it on 5 at the most when using one cabinet at practice and live and when I used two cabs I barely have it on 3.

The only other thoughts I had was since I play live most of the time with two cabs if all the other stuff that takes up electricity on stage is sucking a lot of power from everything and my amp is not getting enough juice from where it is plugged up at on stage. It didn't matter if I ran through the P.A or if I was just mic-ed. That sucker still managed to cut out. I run my amp through a Furman Power Conditioner then I usually hook the power conditioner to a extension cord (which there was nothing wrong with the extension cord no shorts or anything). I am trying to figure out what I can do to fix this problem without having to buy a voltage regulator, etc. It has really boggled all of our minds and a lot of people tell me that a voltage regulator would probably fix my power problem. Don't suppose having the amp plugged up to the Furman Power Conditioner could have anything to do with it?