Silly question? do I need 4 OHM pa speakers for an amp that is 4 OHMs

R

rockironwebb

senior newbie caveman
The reason I am asking is due to an earlier post, I am trying to find speakers that will pair well with my Peavey cs400. MORE confusion on my idiot part. I have been reading about the whole speaker power concept to the point where i am stumped. Seems that the majority of PA speakers out there, whether they are pre-built or replacement speakers are 8 OHMS.
In fact many of the 4 ohm speakers that I can locate are replacement speakers labeled guitar speakers

peavey CS-400------200watts @4 OHMS per channel.
I am on a budget. My band mates don't have any interest getting into the technical stuff, to them, speakers are speakers and I have given up on trying to explain to them that before I open my wallet for anything, I like to know that I am getting something that is absolutely needed and will work well and be efficient. They keep sending me links for any PA speaker pair. The last one was a pair of 1000watt DJ speakers each with 2 15"s2 mid horns and 6 high tweeters. They look at me like I am crazy when I try to tell them that our 200 watt per channel amp will probably not drive those speakers efficiently.
anyway, so the question,
200watts @ 4 OHMS, do I need 4 OHM speakers?? any site suggestions for where to find em?
Oh yeah, I know I have been on this topic for many months, Up front apology for repetitiveness.
 
Your amp will deliver 200watts when it sees a 4ohm load - so two speaker cabs at 8 ohms each on the same channel will equal 4 oms.
 
the whole ohms/speaker/amp situation just kinda blows my mind. I feel like it's really simple, but I've just never been able to grasp it lol. If someone wants to give me a siiiiiiiiiiiiimple explanation, that would rock.


That's why I stick with active stuff :D
 
Ohms add up in series, divide in parallel.

If you have two 8 ohm speakers in a cabinet wired up in parallel, then the cabinet will have a 4 Ohm rating. Similarly, if you have two 8 ohm cabinets hooked up to the amp in parallel, the amp will be seeing a 4 ohm load.

Parallel means you would hook up the + from each cabinet together to the amp, same with the - wire, don't plug them into separate output jacks.
 
thanx for the intel. My issue seems to have worked itself out on it's own. After going on a rant about the cash I've invested into gear and how I am tired of bleeding stones trying to mix and match shit gear, two of my bandmates must have felt sorry for me and took it upon themselves to order a brand new peavey PA package, powered mixer,speakers and cables. I think my next bitchfest will be about the poor quality of my cymbals and how we could truly be a better band if I was able to upgrade, maybe I can guilt someone into getting that $400 mega-bell ride I've always wanted. Thanx again, those were simple enough explanations for me to fathom.
 
Impedance is the property of resistance to back and forth electricity like audio, and it's measured in ohms. When the electricity is a one way thing the resistance is just called resistance and it's also measured in ohms, just to make things interesting.

Amplifiers need loads of the right impedance. If it's too low they would put out more power than they are designed to produce. Most amps are designed for at least 4 ohms, some can handle 2 ohms. The lower the impedance presented to the amp the higher the output, but also the more stress on the amp as it releases more energy and produces more heat. A higher impedance load keeps the amp from putting out as much power and making as much heat.

It's quite safe to put an 8ohm load on your amp, and if you have 8ohm speakers you can parallel two on one channel for a 4ohm load. That way you can have four monitors. You can control the volume of the speakers in pairs, and feed each channel a different mix if needed and if your mixer allows.

I'm suspicious of packages. Find out what you're getting and let us know. It might be worth sending it back in trade for a good pair of wedges or something, or it might be a good deal.
 
Buy a multi meter (about $20) so you can check the impedance when hooking up multiple cabs.

A CS400 gives 120watts a channel into 8 ohms and 200 watts a channel into 4 ohms. So if you connect 1 x 8 ohm speaker to each channel you will get 120 watts on each channel = total 240 watts.

If you connect the 2 x 8 ohm speakers on one channel you will get 200 watts from 1 channel and nothing from the other due to no speaker connected (keep the volume turned down on the channel with no speakers or you will fry the amp).

So I would connect 1 x 8 ohm speaker to each channel and get the 240 watts, later if you buy 2 more 8 ohm speakers, you can connect 2 x 8 ohm speakers to each channel and get the full 200 watts a channel = 400 watts.

Alan.
 
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