hi, im new here and new to fixing gear. my basement had about 12in sewer backup from a few weeks back when it rained to the extreme. anyways, my crate glx 212 was in the basement along with many other things but luckily the electronics didnt get damaged, just the speakers from sitting in water for so long before it drained.
i just purchased 2x12" clestion rocket 50's at 60w and 8 ohms per speaker. the amp is 120w rated at 4ohms...here is the pdf so you can see the details for yourself http://img3.musiciansfriend.com/dbase/pdf/man/m_487689.pdf
the speakers that were in there were Crate Custom Designs at 65w each speaker, which struck me as odd seeing as you would need at the most 60w each to add 120w of the amp, but hey, im completley new to this whole thing so what do i know lol. what also struck me as odd was the way the wiring was set up. it seemed it was run in a series which is the way i hooked up the new speakers as well, but if the amp is rated at 4ohms and the speakers they had in there were 8ohms each(i think?) then shouldnt it be run parallel to cut the ohms in half to equal 4?
i will try and get some pics up soon that i took of the old speakers before i took them out, untill then heres a lil description for ya...there is one positive and one negative coming from the amp, they both went into the left speaker(left speaker since im looking from the back of the amp) then there was another negative and positive connecting the left and right speakers. this is series wiring correct? ill try and get those pics up soon.
thanks in advance for any help. im very inexperienced and trying to do my best to undertand this. i just cant for the life up me understand why the manufactuers would wire it in series, i wired them up the same way with the new speakers just for the fact that i would assume the manufactuers know more than i do lol.
chitownconley
Your Crate amp is 120 watts, the speakers combined had a handling power of 130 watts. This is normal. You usually want speakers that can handle more power than the amp is rated. Actually, that is a little low because a 120 watt amp can produce much more during peaks, perhaps as much as 200 watts. So, for a 120 watt amp you would usually want speakers that could handle say, 150 watts or more.
But those 60 watt speakers should be fine unless you really max the amp out.
As for wiring, check out this site, it has diagrams of parallel and series wiring.
http://www.dallasguitarrepair.com/news.html
I would wire those speakers in parallel for a 4 ohm load. This will allow your amp to put out maximum power. If you wire in series it will be a 16 ohm load. This is much higher resistance than your amp was designed for. It will work, but it is kind of like driving with your foot on the brake pedal, your amp will not be able to put out maximum power. It will be far less loud, and probably the tone will not be as good either.
Even though those two 60 watts speakers (total 120 watts handling power) is slightly less than you should use for a 120 watt amp they will work. You could actually run a 120 watt amp into a speaker rated only 10 or 25 watts handling power. It will work and sound fine if you don't crank the amp up. But if you crank the amp it would blow these speakers quick. You can hear when a speaker is truly overdriven, it will clip or distort badly. You will hear it.
If you know something better than Rock and Roll, I'd like to hear it - Jerry Lee Lewis
thanks for the wattage clear up. well there is only one positive and negative coming from the amp so i can only wire it in series right now. how should i go about hooking up another positive and negative from the amp so i can run them parallel?
i still cant understand why crate would wire it in series if it should be in parallel?
Run two seperate wires from the positive amp wire to the positive lead on each speaker. Run two seperate wires from the negative wire on your amp to the negative leads on each speaker.
Look at this pic.
You could put a male 1/4" jack on your amp's wires. Attach positive to the tip, negative to the ring.
Then attach two wires from the positive leads on each speaker to the positive lead on the female 1/4" socket, and two wires from the negative leads on each speaker to the negative lead on the female 1/4" socket as shown.
All I can guess about Crate wiring it in series is this. At 4 ohms your amp is going to produce 120 watts which is really a little too much for speakers with only 130 watts handling power. At 8 ohms you get about 70% of the power at 4 ohms or 84 watts. But you cannot configure two 8 ohms speakers to get a total 8 ohms load, it is either 4 ohms or 16 ohms (parallel or series). So, they wired them in series for a 16 ohm load. This will get about 70% of what you get at 8 ohms or roughly 60 watts. Now, you have a great match. Now you have speaker handling power that is double your amps output, this can even handle peaks. So this is why I think they did this. But they like to advertise the amp's power at 4 ohms because it looks much more impressive.
The truth is, you were playing an amp putting out about 60 watts, not 120.
With these speakers in parallel for a 4 ohms load, your amp is going to put out more power. It will be slightly louder too. But it can also blow the speakers easier. So don't max it out.
You should call or e-mail Crate and ask them if it is really safe to operate this amp at 4 ohms. If it is not, the amp could overheat and fry (too much current flow through the amp).
If you know something better than Rock and Roll, I'd like to hear it - Jerry Lee Lewis
you know the pdf for the crate amp says the speakers are 8ohms, now that i think about it they are probably 8ohms together, not seperate which would make each speaker crate put in their 4ohms a piece. i bought two speakers at 8 ohms each so i should probably take em back and get 4ohm speakers then lol, man i do everything bassackwards haha
thanks for the help wes
By the way, I never did say Welcome to GuitarNoise. :D
No, I think you have it right. I just went to that page, the way I understand it, it is saying your amp has two 12" Custom Designed speakers rated 8 ohms each.
If those are indeed 4 ohms speakers, then in series they total 8 ohms. But 8 ohm speakers are far more common. In fact, 16 ohm speakers are far more common than 4. Plus, 4 ohms are usually a little more expensive. So I'm betting those are 8 ohms each.
You can see the 1 X 12 version of your amp has one 8 ohms speaker. Your speakers are probably the exact same model.
Probably your best bet is to wire those speakers in series just like the originals. Then you know you won't have any problems.
If you know something better than Rock and Roll, I'd like to hear it - Jerry Lee Lewis
