Quote:
Originally Posted by stockbass  I just got myself the new iamp300 and a wizzy12 and I have some very basic questions. If I want to use another amp with the wizzy, are there somethings I need to be careful of concerning that the wizzy is a 4 ohm speaker?
I have basically the same question when using another speaker with the iamp. Can I plug a 8 ohm speaker to it? If I want to add a speaker next to the wizzy, can it be a 8 or should it be a 4? Can I damage the amp?
thanks
TD |
The answer above is quite correct. Okay, it's 2.7 rather than 2.4, but close enough!
I'll expand a bit:
Most, if not all, instrument amps will handle a 4-ohm load just fine. So in answer to your first question, you can use just about any other amp to drive the Wizzy provided, of course, that it can supply sufficient power.
The difficulty comes when the impedance of the speaker, or combination of speakers, is
too low. The iamp300 can certainly handle a 4-ohm load. So, in answer to your second question, having it drive an 8-ohm load is no problem in terms of what its circuit can handle. You should be aware, however, that you probably cannot achieve the same 300 watts into an 8-ohm load. With most solid-state designs (like the iamp300), the available power decreases as the impedance of the speaker increases.
Your concern with any such amp is what is the
minimum impedance that it can handle safely. I do not know what that minimum is for the iamp300 and I could not find such a spec on the EA website or in the manual for the iamp200 on which the iamp300's output is based. When you plug in additional speakers to the output of an amp, you are connecting them in parallel and the combined impedance (treated as resistance here) is:
R
T=(R
1R
2)/(R
1+R
2)
where R
T is the total and R
1 and R
2 are the impedances to be combined.
So, if you combine two 8-ohm speakers, the combined impedance is 4 ohms. If you combine an 8-ohm and a 4-ohm, the combined impedance is 2.7 ohms. If you combine two 4-ohm speakers, the combined impedance is 2 ohms.
Thus, if the minimum impedance the iamp300 can safely drive is 4 ohms, then you should not combine any speaker cabinet with the Wizzy if you are driving it with the iamp300 because it will likely overheat, in which case, it will probably shut itself down via internal protection devices or it can even be damaged. If the iamp300 can safely drive a 2-ohm load, then you're good to go with any of the combinations I described.
The only question left to answer concerns the minimum impedance that the iamp300 can handle safely. I hope someone will chime in with that information.
By the way, if you wire speaker cabinets in series, which I definitely do not recommend, then the total impedance is simply the sum of them.
With regard to stacking/combining cabinets, you may find
this thread of interest.
