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View Full Version : Blown speakers due to amp?



KrazyMofo24
03-15-2010, 03:30 PM
I feel like a complete idiot right now. I just put together a system and have had so many problems. I purchased an Rockford Fosgate P650.2 amp last week it's rated at 175wattsx2. My speakers are the Alpine SPX-13REF 5.25 component set. After I hooked up the amp to the speakers I noticed my right woofer cutting in and out. It would stay for a few minutes then go out for a few minutes, then finally no sound at all from the woofer. I thought it could have been a loose wire. I checked the connections and no sound, I pulled the speaker out and ran a short cable directly to the amp without the crossover and still nothing. Today the left woofer went out I had the volume at 25 the max is 35.

So now I have two woofers with no sound, but the crossovers and the tweeters are still working.

I have the amp at High pass filter, the cd player crossover was set at 120hz.

The power ratings for my speakers is RMS Power Cap is 60W and Peak Power is 170W. I was on the understand that you can have a more powerful amp, because it would give the speakers more headroom.

Did the amp blow the speakers or could it be something else?

bigaudiofanatic
03-15-2010, 04:07 PM
Sounds like a bad amp or you fried the speakers by either a clipped signal or just a bad amp.

What are your setting for the head unit and amp on?

KrazyMofo24
03-15-2010, 06:21 PM
I have an Alpine CDA-9851 I just had the crossover set to 120hz, the amp was on high pass filter. I left the gain in the middle. I guess its too much power for those speakers.

TakeTheTime
03-15-2010, 07:42 PM
Sounds bad, sorry dude :( Can I just ask you guys about something, about the same thing?
I too have a 5.25" comp.set, I have Polk Audio SR5250, and me and my buddy was testing
a new JL subwoofer today, at some high volume levels. At one point where we cranked a bit,
I heard the SR5250-woofers "rattle" with the bass (HPF 80hz), played like this for 1 or 2 min.
The speakers aren't fully broken in, only like 25-30 hours. They're powered by amp with 100w RMS.
Question: Could this have damaged the speakers?? After the volume-cranking, they sounded nice again... :o

Installer4life
03-15-2010, 10:06 PM
I would say the amp did not blow the speakers. The amp does have the ability to produce more power than the components are designed to handle but other things have to be considered. You can't make a estimate of output of an amp based on a volume of 25 out of 35 or whatever numbers you have. I have seen those same Alpine speakers blow within minutes of be powered up. Even if you have the volume high doesn't mean the amp has reached its max output. I get so tired of hearing I only had it on 35 out of 60 because its nonsense. I would say that the speakers are more at fault.

arun1963
03-16-2010, 12:42 AM
To the OP: Where is the gain set on the amp?

A 2x175rms amp with improper gain settings could very easily blow speakers rated 60watts rms.

Yeah you want headroom, but you want it relative to your speakers capacity to handle continuous (rms) power. Normally around 30% more than your speakers rms is good. This in your case would have been around 2x80watts. 2x175watts is just overkill and lethal as proven. ;)

arun1963
03-16-2010, 01:28 AM
Sorry, missed that you set your gains at around 12 o'clock. Yeah thats way too high.

TakeTheTime
03-16-2010, 02:04 AM
To the OP: Where is the gain set on the amp?

A 2x175rms amp with improper gain settings could very easily blow speakers rated 60watts rms.

Yeah you want headroom, but you want it relative to your speakers capacity to handle continuous (rms) power. Normally around 30% more than your speakers rms is good. This in your case would have been around 2x80watts. 2x175watts is just overkill and lethal as proven. ;)

Hey, did you see my question? My gains were at +0.5V with the SR5250 (they handle 100w rms)...