9 Tips for Installing car audio - Ford Forums - Mustang Forum, Ford Trucks, Ford Focus and Ford Cars

Kim · 04-07-2004, 20:50

1. Don't use cheap speaker wire. That really thin cheap wire really drops off the sound quality at the speaker. It doesn't cost much to get good quality fine stranded dual core speaker cable.

2. Solder your connections. Crimping connectors can lead to poor connections and higher resistance joins therefore reduces the signal getting through to your speakers.

3. Planning. Don't cut anything until you have checked it thoroughly. Both sides, all sides, in and out. It is better to use a board on a back deck than to cut open the deck to make bigger holes. Many cars have the small 3x4 inch holes than won't take 6 inch round or 6x9 speakers. Better to make up a board to raise the speakers (an improve resonance) than to cut out holes. In many cars it is illegal to cut too much of the metal away in the rear deck (supposedly compromises body impact integrity...).

4. Testing! Always test everything before you put trims back on and screw the head unit into the dash. It is easier to fix problems with everthing still out.

5. Instead of using the earth in the wiring loom, find a screw that goes into the metal of the body to earth your amps and head units. Poor earthing causes untold problems from scrtchy sounds, signal clipping, tapes playing all wonky, reduced radio reception, poor tolerance to bass boosting. Also, unbalanced earthing between amps and head units cause nasty nasty static or humms.

6. Make sure you KNOW what that wire you get constant/accessory power from is for! If in doubt run new wires directly from the fuse box (yellow for accessory and red for constant). Be careful and make sure there is a fuse in the circuit somewhere.

7. Make sure your speakers and amps are balanced. When buying speakers some of the better quality ones are rate with RMS (Root Mean Squared) others are rated with Max (or PMP - Peak Music Pressure). As a rule of Thumb 50W RMS would perform as well as 80-90W Max. In fact, Many speakers that say they can handle a millisecond burst of power to 200W (for example) are really only about 80 watts RMS on a good day. Many car amps are the same. that 4x150W amp is probably only putting our 4x60W RMS.

On that note, If you have 4 quality 50W RMS speakers they can produce more sound than your ears can hear. If you run them with a 4x200W (Max)cheapie AMP they should rock!

8. RCA from Head unit to AMP is ALWAYS to be preferred.

9. OK, in general the sound is only as good as the weakest component. I find that good wire, connections, power make a huge difference. Average and even cheapie amps do fine (if they are big enough). Speakers make a big difference especially with bass response. Most head units (except for crap cheap ones) produce good quality CD audio these days so are not as important.

Hope this helps,
Kim
(Used to own a car stereo and alarm installation business)

Hamo · 04-07-2004, 20:58

you should have put 1 tip per post...hehe...then you would have enough posts in no time!

but thanks for the handy tips anyway

TEguy · 04-13-2004, 02:51

I dunno
I'd preffer average speakers and average amp instead of good speakers and cheap amp

ianmcginley · 04-13-2004, 03:32

Quote:

Originally Posted by rrt802000

I dunno
I'd preffer average speakers and average amp instead of good speakers and cheap amp

A cheap amp will distort the signal way too soon over a good amp - this will lead to poorer signal and eventually burnt out cones due to the feeding of a DC signal to the voice coil.

Now a good amp and cheap speakers - impedance in the speakers could be poorly tuned to the reactive load when delivered. This can induce failures in components due to varying signal power (proportional to reactive load).

Personally i'd save the extra few weeks or whatever and buy a good amp and good speakers with good cable - if you are looking for some quality systems.

Otsile · 04-13-2004, 05:43

from personal experience when getting a sub, get an amp that can handle the power requirements of the sub. got a comp kicker sub real cheap, but ended up having to pay almost $2000 for an amp and caps that could make the most of it. :(

davway · 04-13-2004, 05:53

id like to make a point as well...took 2 years before anyone picked it up. make sure your head unit is strong enough to run the speakers you have (this is a non amp, non sub system) i was running 220watt $500 2 way speakers off a factory AU 6 stacker......3 times i blew speakers well under talking volume. i mean you could hardly hear the stereo when the speakers blew......turns out the factory 4x25watt isnt enough to run such powerfull speakers.....4x45 is the minimum for such capacity speakers. dont know how its calculated but make sure the head unit is good enough.

TEguy · 04-13-2004, 07:49

Quote:

Originally Posted by ianmcginley

A cheap amp will distort the signal way too soon over a good amp - this will lead to poorer signal and eventually burnt out cones due to the feeding of a DC signal to the voice coil.

Now a good amp and cheap speakers - impedance in the speakers could be poorly tuned to the reactive load when delivered. This can induce failures in components due to varying signal power (proportional to reactive load).

Personally i'd save the extra few weeks or whatever and buy a good amp and good speakers with good cable - if you are looking for some quality systems.

So you basically agree with me ianmcginley :oo3:

Kim · 04-13-2004, 15:08

Quote:

Originally Posted by ianmcginley

A cheap amp will distort the signal way too soon over a good amp -

Right. Let me explain it to you. When you install an amp you adjust the levels on all the channels. You don't just turn them up to max. A 4x200w cheap amp will not put out as much sound as a 4x200w expensive amp. In my experience it will only put out enough clean signal to drive the quoted 50w RMS speakers properly. You turn the amp down so it is operating in it's middle range which means it will NOT clip the signal. Simple. Even expensive amps will damage speakers if you do not tune them to operate in the correct way.

Kim

ianmcginley · 04-13-2004, 17:31

Quote:

Originally Posted by Kim

Right. Let me explain it to you. When you install an amp you adjust the levels on all the channels. You don't just turn them up to max. A 4x200w cheap amp will not put out as much sound as a 4x200w expensive amp. In my experience it will only put out enough clean signal to drive the quoted 50w RMS speakers properly. You turn the amp down so it is operating in it's middle range which means it will NOT clip the signal. Simple. Even expensive amps will damage speakers if you do not tune them to operate in the correct way.

Kim

So you agree with me saying that a cheaper amp at the same advertised specifications of a more expensive amp are likely to clip the signal.

The issue is that a cheaper amp is more likely to clip at lower frequencies (I have this proven in a year 12 physics report I did on signal to noise ratios on car audio). Clipping the lower frequencies (sub 100Hz) does not produce an audible sound difference until the S/N gets to about 30%. Lower frequencies also take less power to distort (greater power required to generate a clean signal).

Now when you clip low frequency - it produces a longer DC instance over the clipping of high frequencies. However you can notice (hear) the difference in high frequency clipping at less than 2% S/N (above 10,000Hz).

This is why it is so important to have good clean reliable power (ripple removed by large capacitors) to your higher quality amps to make sure you have as good signal delivered to those expensive speakers.

So where does this put our discussion - nowhere really. I think we are all saying the same thing in round about fashion and we are all in agreement. I just like to embellish on the details so people know 'why' it is so, not just because someone said so. This gives me heartache when I want to do something but I want to know 'why' :)