Recently I was given a set of lower end rockford speakers as a present and a week or 2 after installation, they blew. I've gone through 3 speakers (the owner of the local store where they came from keeps replacing them). After playing at a moderate to high volume (not exessivly loud) the sound switches from clean to distorted and quiet. It happens after listening for about 30 minutes.

I'm starting to think the problem is in my head unit. I ran the speaker wire that came with the speakers right from the harness on the back of the deck. Tried a few other sets of speakers and they all sound different than in the store. Mostly much more quiet. Almost positive I connected the pos / neg correctly.

Does anyone have an idea what is causing this problem?

Deck - JVC KD-LH 3150
Speakers - Rockford 6" FRC4206U

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by mikeds122 &raquo;</TD></TR><TR><TD CLASS="quote">Recently I was given a set of lower end rockford speakers as a present and a week or 2 after installation, they blew. I've gone through 3 speakers (the owner of the local store where they came from keeps replacing them). After playing at a moderate to high volume (not exessivly loud) the sound switches from clean to distorted and quiet. It happens after listening for about 30 minutes.

I'm starting to think the problem is in my head unit. I ran the speaker wire that came with the speakers right from the harness on the back of the deck. Tried a few other sets of speakers and they all sound different than in the store. Mostly much more quiet. Almost positive I connected the pos / neg correctly.

Does anyone have an idea what is causing this problem?

Deck - JVC KD-LH 3150
Speakers - Rockford 6" FRC4206U

</TD></TR></TABLE> IF you are using a HU to power the speakers, and depending what you mean by "moderate to high volume", [on a scale of 1 - 10, 5-7 maybe 8 is max] it is very easy to drive the HUs internal amp to "clipping" and that burns up speaker VCs , one thing I would do , if not done already, run a fused 10ga wire from the batt. to behind the HU and hook up the HUs yellow, constant power wire to it, and run a ground from the chassis of the HU to the cars chassis for a better ground. if power, [or lack of] is the problem with the HU, that will fix it.
If on the other hand you have a problem with the HU, [ sound gets distorted after playing for a while] something in the HU may be shorting out after it heats up, [output IC] it may be sending a lot of DC volts to the speakers. 94

 

Thanks. What I'm still curious about is why even new speakers hooked up to it sound odd and really quiet. When in the store, they sound much louder and different playing off a similar HU even in a big room?

And to be a bit more clear with the way the speakers blow - after playing music for about 30 - 40 minutes, the sound will just switch from a clean loud sound, to a quiet distorted sound. It just changes like flipping a switch and they don't sound better after letting the HU cool down - in fact, they still sound blown off a different HU.

 

Once you burn the VC the speaker is toast, it will sound no better with another HU, that said, for both speakers to go like that at the same time is odd, I would have your HU checked 94

 

The thing you popbably did'nt know most of the speakers in stores are usually hooked up to an amplifier. Most head units only put out about 10 to 22 watts of power while most speakers can handle 50 to 125 watts of continous power. Which explains why when you play your speakers at a moderate to high levels , you are pushing your headunit to hard, and your speakers are not getting enough power. A safe bet is to invest in a 4 channel amplifier. Then you might get the sound you are looking for.

 

The speakers did not both blow at the same time actually about a week apart... As for an amplifier in the store, the sales person had a switch to compare what the speakers sounded like amplified compared to just playing off the HU. It was much louder when amplied but still louder even off the HU.

 

Well I totally agree it is the head unit, but give me some info is it a stock or aftermarket head unit, and usually the speakers wont blow at the same time unless they are getting to much power and even then.......
And what are the guys replacing your speakers saying the problem is?
I just suggested an amplifier as a fix, but you could also replace the head unit as long as it has good RMS power.

 

They did NOT blow at the same time... (mentioned above)

The HU is JVC KD-LH 3150 (it was a fairly high end JVC deck at the time of purchase)

Speakers are Rockford 6" - FRC4206U (lower end speakers )

(these things were noted in the first post )

I understand that the deck puts out next to nothing in RMS power but for new speakers to blow so easily seems pretty pathetic even if they were really cheap (i think my friend paid $80 CDN).

The guy who my friend bought the speakers from is an idiot. I live in a small town and its a small AV store in the area... He's just interested in selling and doesn't care about what happens after the sale. He just wants to keep replacing me the same speakers when they blow and doesnt understand or care why they keep blowing. I think the only reason he's even replacing them is because he knows me personally but he or no one in his store has any knowledge about the subject

 

Yeah! Sounds like a decent deck. and the speakers should not blow that easily. F@*k those guys at the stereo shop. I had a guy I hooked up a radio and speakers for kinda have the same problem. He just ended up junking his deck. We installed a pioneer 6700 deck and a rockford fosgate punch series amp. Nothing major but good enough for him.

 

Do you have all the enhancement settings on (ex:bass and treble)? If so, that will distort your speakers and put more pressure on them which will cause them to blow.

 

No other enhancements. I have the bass way down low, pretty much to the bottom - use my sub for lows. The speakers were basically just playing mids and highs. I listen to mostly rock, alternative etc.

Thanks for the input guys

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by mikeds122 &raquo;</TD></TR><TR><TD CLASS="quote">The speakers did not both blow at the same time actually about a week apart... As for an amplifier in the store, the sales person had a switch to compare what the speakers sounded like amplified compared to just playing off the HU. It was much louder when amplied but still louder even off the HU. </TD></TR></TABLE>Sorry I got the impression that they would blow at the same time....
<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by mikeds122 &raquo;</TD></TR><TR><TD CLASS="quote">And to be a bit more clear with the way the SPEAKERS blow - after playing music for about 30 - 40 minutes, the sound will just switch from a clean loud sound, to a quiet distorted sound. It just changes like flipping a switch and THEY don't sound better after letting the HU cool down - in fact, THEY still sound blown off a different HU. </TD></TR></TABLE> When a VC shorts out, it can be like flipping a switch, and the only way to tell is to cut the VC out of the speaker, [a blown one] if the VC is clean, no marks on it and a clear copper color, the problem is the speaker, if on the other hand they are discolored, burnt looking, the problem is in the HU, [its defective] or you are turning it up to the point of clipping, let me try and explain, your HU is rated at 4x50watts max, I can't find a spec. sheet for it, so lets say it's 4x25watts RMS, [I think I am being generous] when the amp is making 25watts the distortion rate, [THD] is .05%, [again no spec. sheet] .05% is very "clean" but as you turn up the volume, and as the amp starts making more watts, the THD goes up, at 50watts, [the HUs rated max power, per ch.] the THD is at about .5% or higher, but the HU can probably make 75-100watts for short "bursts" and that is where the problem is, the TDH can jump to well over 1% and that is "clipping" and speaker VCs can blow like a fuse, [flipping a switch] 94

 

Thanks, interesting stuff. I got 2 new replacements again today. Put them in, and they sound fine... Going to just play music at even lower volumes I suppose until i can afford a small amp. Thanks again for the advice