crackle crackle has my speaker blown?

[Gwynleym10]

I have a set of Xo-525 pro-plus components in my foot wells, drivers side has started to crackle. took speaker out and tried in on the rear calbes, still crackled so its the speaker.

There only about 8 months old and I can't see any cracks in the cones. They are rated at 280w 4 ohms and I don't have an amp only the HU which is 4x35w

Has the speaker blown or is it something else? thanks for any help

[ian332isport]

I have a set of Xo-525 pro-plus components in my foot wells, drivers side has started to crackle. took speaker out and tried in on the rear calbes, still crackled so its the speaker.

There only about 8 months old and I can't see any cracks in the cones. They are rated at 280w 4 ohms and I don't have an amp only the HU which is 4x35w

Has the speaker blown or is it something else? thanks for any help

Gwyn,

Although the speaker has blown, it's probably due to the HU clipping the signal and frying the voicecoil in the speaker.

The speakers may be able to handle a clean 280w signal, but the head unit, although rated at 4x35, is in reality only going to be putting out around 12w. If you tend to play this quite loud, the signal will 'clip', and effectively feed the voicecoil a DC signal that will fry the coil. You could run speakers rated at 1000w, but a clipped 12w signal will still fry them.

You either need to get an Amp, or turn the volume down a bit

Cheers,

Ian.

[Gwynleym10]

You either need to get an Amp, or turn the volume down a bit Very Happy

Thanks Ian

Looks like its amptime then as I can't see the stereo being turned down...

Any good amps to look out for, nothing too flash?

Thanks

[Andy_magic]

There are a few Vibe VP series amps floating around on ebay.

I've got a VP2 running a sub and for the money I'm very impressed.

One thing to watch with smaller speakers (anything less than 6x9) is that they won't be happy pumping out lower frequency sounds.

If you can, run a high pass filter on the speaker outputs, this will cut the bass to smaller speakers, leaving them to do what they do best. If backed up by a decent sub and amp you will find you can run the system at higher volumes without distortion or risk of blowing your speakers.

[hellomoto]

can u explain wat u mean by a high pass filter

[ian332isport]

can u explain wat u mean by a high pass filter

First, a bit of theory.

The audible frequency range that human's can hear is 20Hz to 20KHz. Reproducing sound outside of this range is pointless. Different types of speakers are capable of reproducing different ranges of frequencies.

Subwoofers (subs) produce low frequencies (typically 20Hz to 100Hz).
Mid range speakers (mids) produce the mid range frequencies (typically 100Hz to 4KHz).
Tweeters produce the higher freqencies (typically 4KHz to 20KHz).

In general, if you feed a speaker the wrong frequency range, it will at best sound nasty, and at worst it will die a horrible death.

The points where the frequency changes from being low to mid, and mid to high, are known as the crossover frequencies. This is where the term crossover comes from. A crossover, is a collection of electronic circuits that take a full range input signal, and splits the frequencies up and sends them out to the different speakers. It will direct the high frequencies to the tweeters, the mid range frequencies to the mids, and the low frequencies to the sub.

This crossover circuit can be broken down further into the different types of filters. A high pass filter is something that takes a full range signal on it's input, and only allows the high frequencies to pass through. It effectively blocks the low frequencies. A low pass filter is the opposite. It allows the low frequency signals to pass, and blocks the high frequencies. The mid range signal is selected using a band pass filter. This allows all the frequencies in a particular band to pass through. It blocks the high and low frequencies, and just allows the mid range frequencies through.

By changing the values of the electronic components that make up these filters, you can change the crossover frequency points.

I think that covers most of the basics

Ian.

[Adam318i]

Thanks, that even hepled me out

[hellomoto]

right i kinda understand the 'theory', but am still a bit lost. At the mo iam runnin an alpine 60w x 4 HU with 3 outputs(front, back and sub) at present iam runnin 5 and a quarter alpines coaxial in the front and 2 5 and a quarter infinitys coaxial in the rear off the head unit, and runnin a sub through an amp off the sub out put. Firstly is there ne need for wat u recommend at the moment, and secondly wen i upgrade my system iam gonna run 6inch components speakrs front and back from my front and back outputs, will i need them then.
hope u understand
also when i upgrade i was thinkin of keepin the 5 and a quarters runnin off the HU, do u think there is ne point because there is a feature on the stereo where u can turn off the internal amp
thanks for the help
j

[ian332isport]

right i kinda understand the 'theory', but am still a bit lost. At the mo iam runnin an alpine 60w x 4 HU with 3 outputs(front, back and sub) at present iam runnin 5 and a quarter alpines coaxial in the front and 2 5 and a quarter infinitys coaxial in the rear off the head unit, and runnin a sub through an amp off the sub out put. Firstly is there ne need for wat u recommend at the moment, and secondly wen i upgrade my system iam gonna run 6inch components speakrs front and back from my front and back outputs, will i need them then.
hope u understand
also when i upgrade i was thinkin of keepin the 5 and a quarters runnin off the HU, do u think there is ne point because there is a feature on the stereo where u can turn off the internal amp
thanks for the help
j

If you are running coaxials (mid & tweeter in one unit), then they will most likely already have a small crossover built into the speakers. This may be as simple as a single capacitor connected across the speaker terminals, or possibly a small circuit board with a few other components. Either way, you don't really need a separate crossover with these.

When you upgrade to components, you will need a crossover, but they should come with a crossover anyway. I've never seen a component set that doesn't include some sort of crossover.

As your HU has a separate Sub out, then it may have a crossover built in. This will usually have a few different crossover frequencies you can select in the menu somewhere. If the HU does not have a built in crossover, then the Amp may have one (really can't say without knowing what amp you have). If on the offchance you don't have a crossover on the HU or the amp, then you really should get one. You're not going to damage the Sub without one, but you will be feeding it a load of frequencies that it cannot reproduce which is going to stop it performing at it's best.

To be honest, if you are looking for sound quality, rather than just volume, then you really don't want any speakers in the back at all (apart from the sub). You are better off spending extra on the front components and a really good amp. I know it sounds odd not having rear speakers, but with good front components, a decent amp and a good sub in the back, you won't need them. If you really want rear speakers, then just run the 5 1/4" coaxials off the HU for a bit of rear fill.

Ian.

[Andy_magic]

Great explanation there ian

Sounds like a V-Drive Alpine to me, I would be surprised if it hasn't got built in X over selection.

what model number is it.

I've just picked up a TDA-7592 (60x4 watt V-Drive Tape deck) with a changer off ebay for Ԛ£68, the changer WAS faulty. It isn't now, they dont call me Andy Magic for no reason....

Anyway, boast over, this headunit has built in high pass and low pass filters (X-Over) I've set the high pass filter to 120hz and the low pass for 120hz too, the main speakers get frequencies above 120hz and the sub anything below that.

I've got alpine components in the footwells running BMW premium sound mirror pod tweeters and alpine co ax's in the rear deck.

In a moment of weakness I picked up a Sony 15" pentagon sub in a sealed enclosure (proper tuned for the speaker) for Ԛ£30 off a boot sale. It does actually do the job quite well, not too flappy like some 15's can be, it's running off a Vibe VP2 amp 2x100 RMS bridged. It certainly overcomes the problem of getting bass into the cabin of an E30 - brute force.

If you don't have a manual for your alpine you can download them from alpines site.

[jordano]

sorry for the delayed reply i aint been able to get on for sum reason it is an alpine cda 7893 it is a v drive 60x4 with 4v sub pre and bass engine, thats wat it says on the front, i aint got a man as i got it off ebay. so i dont no about it havin x overs or not

[jordano]

and how do i no wat to set my hidh/low pass filters to, i hav noticed the HZ thingy on the HU wen i hav been lookin through the stuff on it so i got them, they r there wen u turn ure bass/treble up

[ian332isport]

You can download a manual from here:

CDA-7893 manual

This should answer most of your questions

Cheers,

Ian.

[beemerboy3]

sorry for the delay again, cheers ian