I need help with my car's stereo.

I have a hyundai tiburon 97’ with stock speakers. A few days ago, this guy installed a new headunit in my car (Kenwood KDC-MP228) with the help of some adapter cables (which I had to buy).

Now, if i set the volume very low, everything sounds fine but as soon as I crank it up a little bit (anything over 13 out of 35 mystery units) , there is a huge amount of distortion that makes the sound unusable.

the guy who installed it says it’s normal and that I have to buy new speakers for the car because (and I quote): “Bla bla bla resistance x ohms bla bla bla power output too high bla bla bla stock speakers crappy bla bla bla”.

I asked him to stop saying bla bla and to use real words instead but he just looked at me funny then started stabbing me with a big, rusty knife.

So anyways, is this normal? Do people routinely switch speakers when they get new head units? Or did this guy screw the installation somehow and is trying to pull a fast one on me? (if that’s the case, I’m screwed, I already paid him).

Thanks for your time.


Is the max-before-distortion-level (13, I guess) about as loud as the factory radio was? The new radio is 50 watts per channel. It’s unlikely that the factoy unit was close to that much power.

Also, you might mess around with the equalization to try to kill some of the distortion.

It can also be the speaker wires. You might need heavier gauge wires with the extra oomph.

And get a bigger and rustier knife than his.

Absolutely not! The max before distortion level was much higher before. The current level is unacceptable. It’s hard to hear if I even have the AC on to give you an idea.

The guy did mess up with the equal for a bit but it doesn’t seem to make an appreciable impact.

I’d love to tell you what wattage the factory unit spits but it just doesn’t say on the unit itself and googe searches for the model number yield 0 results (it’s a hyundai radio deck radio, not a third party)

I never had a car with stock speakers that did not suck. Even if it is not your specific problem I would recomend replacing them. If you like bass get speakers with a low frequency response, you will get better bass with the same amount of power.

I’m still waiting for an answer to my specific question by the way:

“So anyways, is this normal? Do people routinely switch speakers when they get new head units? Or did this guy screw the installation somehow and is trying to pull a fast one on me? (if that’s the case, I’m screwed, I already paid him).”

Most people I know who have gotten a new head unit did, in fact, get new speakers. It is part scam, part truth. Yes, they want to sell you more stuff, because it’s more money for him, but stock speakers on anything but expensive or sporty cars almost always suck. Bad response to both low and high frequencies, crackles, etc…

First off - to specifically answer your question, yes, it is normal to purchase new speakers when you replace your factory head unit. Factory speakers tend to have lower power handling than typical aftermarket replacements. Smaller factory speakers often use “whizzer” cones for high frequency reproduction, as opposed to a separate high frequency transducer which will reproduce the upper range more accurately.

One thing you should be aware of is that power does not exhibit a linear relationship to performance of an audio system. In fact, a fifty watt-per-channel head unit can only be twice as loud as a five watt-per-channel unit. Many factory decks produce about six watts. If you double the power, you get a volume gain of only 3 dB. Doubling the volume requires a tenfold increase in output power.

What is the THD (total harmonic distortion) rating of your new head unit? This is a measure of how accurately the output from the unit represents the actual program material. Next thing to check, as has already been mentioned, is the wiring. Often, quick and dirty installations are accomplished by means of an adapter to your vehicle’s stock wiring harness - essentially connecting your new head unit to the existing wiring. A major drawback to this is that the existing wiring was designed with the stock deck in mind, and may not be sufficient for the increased current from the new unit. At high power levels, the resistance in the wire may be too high, which can manifest itself as distortion in the audio signal. Without exception, I have always heard better performance out of installations where all new wiring was run. Considering that wire is cheap, it makes sense to do this.

Next, the speakers could simply not have the power handling characteristics necessary to handle the output from your new head unit, although you mentioned that you hear the distortion at lower listening levels than with your old deck? In that case, what immediately springs to mind is that the system was tested after installation, and the volume was turned up to a point which exceeded the power handling of the factory speakers, damaging them in the process. One thing you may want to do is to remove and inspect your factory speakers and power connections. Realistically though, you do probably want to replace the factory speakers with higher quality drivers. Otherwise the increased fidelity gained by replacing the head unit is lost in reproduction.

Contrary to popular belief, when a speaker is “blown”, it is usually distortion that is the culprit and not simply the amount of output power. If you imagine your program material as being a waveform with peaks and valleys centered about a mean listening level, in almost every case the speaker should be able to reproduce that signal, provided that the amplifier (internal, in the case of your head unit) has sufficient headroom to accurately reproduce the peaks in the program material. Of course, these peaks may occur at amplitudes significantly higher than the mean listening level, necessitating a significant amount of power to reproduce accurately. As the mean listening level is increased, it becomes increasingly difficult for the amplifier to reproduce the extreme peaks without distortion. When this does occur, the amplifier “clips”, or chops off the peaks at an amplitude equal to the maximum amount of power that the amplifier can deliver. This is what you hear as audible distortion when you turn your music up loud, and what is likely to cause damage to your speakers if it happens at a level close to the speaker’s power handling ability. When using an amplifier with sufficient headroom to provide enough power to reproduce the program peaks accurately, it is very difficult to blow a speaker with undistorted clean program material as a result of power alone

So, I can’t say for sure what caused your problem, but at a guess, I suspect that the head unit was installed and tested at an elevated level, which sent a distorted signal to your speakers as a result of a combination of the wiring and poor accuracy from the amplifier output at the high power level, which blew your factory speakers, which will now sound crappy no matter what you send through them. Not a huge loss, as you probably want to replace the factory speakers anyway, but you need to be very careful with these car audio guys. As a general rule, they’re the sleazy used-car salesman applicants who were deemed to have insufficient ethics to sell entire cars.

Wow, a thousand thanks for your comprehensive reply Fuji. It was very informative. And thank you too bouv for alleviating my doubts.

Now, if I could impose on you one more time. What speakers would you recommend me? I’m just looking for something decent and I do not want to spend too much money on them.

Fuji has it right.
If you do get your speakers “rewired” make sure your your uping the gauge of the wire. Thin stock stuff may be 20-gauge and you’ll want to get something at least 16-gauge. Any 16-gauge will do. Don’t bother with the overpriced Monster stuff.
Yep, stock speakers are pretty cheap. Going to a decent poly-propelene 2-way speaker can make all the difference. Some basic Pioneers, Sony, Kenwoods will do the trick.
Don’t go overboard with 3-ways, seperates, or high-end Infinity, Boston Accoustics or anything like that. While these are great speakers they rely on a seperate amp with more power to make them worth it. A 50x4 deck is not enough power for them.

And especially important is what Fuji said- Distortion will ruin a speaker, not power. As soon as you can hear audible distortion turn it down. Quickest way to destroy a speaker is to run distortion through it.

I have a personal preference for JBL speakers. JBL changes its product line regularly, but they tend to maintain a budget line, a mid-range line, and a top-end line. In your case, I would suggest the middle quality series, and if you have a choice between 2-way and 3-way speakers to fit your application, go with the 2-way.