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-   Archive through April 04, 2003 (http://www.wakeworld.com/forum/forumdisplay.php?f=62369)
-   -   8 Ohm speakers (http://www.wakeworld.com/forum/showthread.php?t=57292)

heirborn 03-09-2003 3:37 PM

I purchased a set of the West Marine XL speakers a few months ago. The impedence on the speakers is 8 ohms. I am running them off a 4 channel 400w Rockford amp. I was told to run them in parallel which I did. One speaker lead off the negative on one channel and the other lead off the positive of the other channel. I did the same for the other two channels for the other speaker. The speakers are rated for a max of 90w ea. Took the boat out yesterday and one of the speakers is not working. I hooked it up to the side that was working and it is speaker is dead. Neither the woofer or the tweeter is working. How much power is going to it running it in parallel? And I am guessing It is not repairable. Any thoughts? Is it time to purchase yet another set of speakers? Another thing. I heard that speakers have to be broken in. Is this true? <BR> <BR>

cyclonecj 03-09-2003 7:02 PM

You can't do what you did. You could have wired both speakers in parallel to one channel of the amp, with another pair wired to the other. You fried one speaker. It is OK to wire a speaker with higher impedance to an amp, such as an 8 ohm speaker to a 4 ohm output, though you will lose 1/2 power. It will not hurt the amp or speaker. If you put too large a load (too few ohms) on an amp you will fry the amp or the speaker. Usually the speaker. Buy new ones. Or another pair, then you have one extra<img src="http://www.wakeworld.com/MB/Discus/clipart/happy.gif" border=0>

xtigeman 03-09-2003 7:30 PM

Did you switch the amp to bridged? If you bridge channels 1 &amp; 2 and bridge channels 3 &amp; 4, your amp is running 2 ohm 2 channel mode. This would be 2 X 200 at 2 ohm. Then you are putting an 8 ohm load on an amp in 2 ohm which equals a mess. The amp would be putting in over time to drive just 50 watts to the speakers. If you did switch to bridged, chances are you clipped and blew the speaker, but it seems like you would have only blown the tweeter such that no noise is heard. <BR> <BR>I don't know, but seems you would be much better off (and it would make things simplier) getting a 2 channel amp and not bridging to try and power 8 ohm speakers. Also, better to not use 8 ohm with car audio stuff if possible. If you do want to use 8 ohm, then run 2 channel amp with 4 speakers, 2 of which are wired in parallel without bridging.

jmanjohn 03-09-2003 8:26 PM

Open them up and check to see if the wires are connected. They use a light wire and it does come off. I had a set and mine stopped working they were disconnected inside.

shaneo 03-10-2003 5:55 AM

Can Doug (or anyone) "dumb down" his instructions on how to power and wire a set of 8 ohm tower speakers? I just ordered a set of West Marines and would appreciate any advice on amp choices and wiring instructions. Thanks in advance.

shaneo 03-10-2003 12:33 PM

anyone???

salty87 03-10-2003 2:13 PM

8 ohm speakers require twice the power of 4 ohm speakers for the same volume. that's kinda bad for our purposes. <BR> <BR>you can wire 2 pairs in parallel to reduce the impedance to 4 ohms. but, by also bridging the amp like michael did, something was eventually going to give. the amp was driving at 2 ohms while the speakers were 4 ohms.

colorider 03-10-2003 2:40 PM

Bridged my speakers in parallel (west marine) and blew the speakers 3 times last summer. I was giving them 200 watts each, and that was too much. The tweeters blow out of them. I am going to run them regular this summer and see how that works out. The good thing is that they are not expensive and when the speakers blow, just pop out the drivers and put in a set of mb quart components. Get them off of ebay for about 100 bucks a pair and you will have super loud setup that will last. And you wont have to run them in parallel or bridged.

bob 03-10-2003 3:55 PM

Not to discount Doug or Salty BUT if you followed the RF instructions which says to take hot from one channel and ground from the channel beside it you dont do anything to the amp impedance wise(no its not in 2 ohm mode) although since your in bridged mode then you do double the power and when bridged on that amp (I have the same one rf 400.4) you can only go down to a 4 ohm load (which is what you did and that was fine). Where was the gain set when you blew the speaker and did you hear any funny noise out of it prior to it expiring? You should have no problem running 100 watts to speakers rated to 90 watts. Ive also got the speakers Andrew above has but i only toasted the tweaters when they got wet and fixed them (solder joint problem) Ive been running two channels off my 600.4 to the XXLs (300 watts rms) for about a year and a half and havent had any other problems. 8 ohm speakers do need to be run in parralel to get maximum sound.

bob 03-10-2003 4:41 PM

This is the manual for the 300,500, and 700 but they are basically the same, scroll down to the 3-channel wiring diagram. <BR> <BR><a href="http://www.rockfordfosgate.com/ez2/fcsscripts/ExternalFiles/Rockford/2002/Amplifiers/MAN3771C_4ChPunch_MAN.pdf" target="_blank">http://www.rockfordfosgate.com/ez2/fcsscripts/ExternalFiles/Rockford/2002/Amplifiers/MAN3771C_4ChPunch_MAN.pdf</a>

heirborn 03-10-2003 5:40 PM

I did pull the speaker apart and everything is connected. <BR> <BR>Sounds like replacing the speakers with another type is the way to go, that way I don't have to worry about the 8 ohm problem. That would also free up a two more channels. I "had" to hook my four interior speakers back to the deck due to unsing the other for the tower speakers. <BR> <BR>Another question. What happens when you run two speakers off of one channel? I have 6.5 Polks in the boat. <BR> <BR>Andrew, did you replace the tweeter with MB too?

bob 03-10-2003 7:53 PM

Mike you should be able to hook up the two speakers to just the two channels on the same side of the amp leaving the other 2 open for interior speakers. You can run 2 -4ohm speakers off one channel (4 boat speakers off two channels), just run the lefts in parralel and the rights in parralel.

colorider 03-10-2003 8:10 PM

Michael. I replaced the tweeters with some 3.5 inch eclipse 2 ways, and replaced the woofers with some 8 inch pyramid woofers. It was a cheap route to go, and I will see how they sound. I had the speakers receiving too much power, so they blew up. The capacitors inside actually exploded in the xxl speakers which was telling me it was a power problem, not really a speaker problem.


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