I changed my deck for the traffic pro, already a BIG improvement over the cdr-210.

While IU'm at it, I will change the speakers too. No Amp, and NO Sub...just speakers. I dont need anything crazy, and dont want to spend too much on it.

My shop recommended Infinity 6020 CS 6.5 compnents (2 OHMS) for the front door speakers:
http://www.infinitysystems.com/car/p...=US&Region=USA

and for the rear deck, he recommended: Infinity REF6422CF 2 way 4x 6 speakers (2 OHMS):
http://www.infinitysystems.com/car/p...=US&Region=USA

He says these will sound good and wont require too much power..since I dont want to add an amp now. Also, are priced very reasonably.

What confuses me is the OHMS. I have read in the old threads that I need to use 4OHMS for th rears....whats the deal on that?

Also, should these speakers fit in without too much modifying, and is it a reasonable choice?

 

Ohms are a measure of impedance. standard speakers are all 4 ohms. Most amps are rated to drive 4 ohms, although your higher end amps will be 2 or even 1 ohm stable. This makes a differences as power dissapation is calculated by Power=Voltage times Current, where Current is voltage divided by impedance, so the lower the impedance, the higher the current, and the more power dissipated.

I wouldn't fret too much, nearly all speakers will be compatible with a factory head unit.

FWIW: speaker brand/model is much a matter of personal taste. What sounds good to you may not be someone else's cup of tea. Decide what your budget is and go listen to some speakers. Fact is they won't sound the same in your car as in the store display anyway, but at least you can decide if you prefer the infinity vs the polk vs the boston acoustics etc...

You can always add an amp later if you desire. Most anything you put in will be an improvement over the stock nokia speakers, which after 12 years have deteriorated more than likely.

I do recommend spending more money on front speakers, like 2 way components and less on the rear deck, which are for fill anyway.

Don't know if the infinitys are drop in, I have OZ Audio speakers, the 4x6 dropped into the rear no problem, and even uses the factory grill. The 6.5 " fronts required cutting as the woofer and tweeter are larger than the factory non-hi fi set.

 

+1

I bought Polk Audios for the front and rear. The fronts installed easily with only a little cutting (see my thread Door Speaker Installation). The rears were pretty much plug 'n play. The only issue was trimming the spacer so I could use the stock grill.

I spent less than $200 on all of the speakers (fleabay) and it sounds so much better than the stock Nokias.

Good luck!

 

Sam,

if you look on the link you posted you will see that both drivers are in fact 2 Ohm voice coils. There is a not that says there is some tweaking done to ensure that your Traffic Pro will actually see 4 Ohms. How much power does your Traffic Pro put out? These drivers will EACH handle 40 Watts RMS. The sensitivity of 91 dB is an efficiency number that tells you how much acoustic sound pressure per Watt. 91dB is pretty efficient. I'd think you'd have plenty of sound pressure (volume) with these.

 

PS how much are these babies worth?

 

Here is really basic overview of the concept of impedance: Impedance is normal resistance plus the "resistance" that is ccreated by doing work.

Using your 993 as an analogy: As you rev your engine in neutral, there is very little impedance.
Mainly the load on the motor is the "resistance" created by the friction of the parts rubbing against each other in the motor.

When the car is put in gear and the clutch is let out, the impedance rises because the motor is now doing the work of moving the car forward. There is still the resistance of the motor parts, but that is added to the load of driving the car forward. These two things added together are the total impedance.

The car's motor works best in a certain RPM range, it is most efficient at developing torque in this range. For maximum acceleration the motor should be operated in this RPM range.

The rate of applying torque is horsepower. By stepping on the gas the flow of power is increased to do work (move the car forward)

If the car is started out in 2nd gear, the motor will lug in an inefficient part of the torque band and the car will not move forward quicky. This is because the motor is loaded down with too much impedance. The impedance is too high—power is applied, and very little work is done, because even though the power is there, it doesn't get transferred efficiently.

If the car is started in 1st gear the motor has a very comfortable impedance load and moves forward easily–an efficient power transefer from the motor to the drive wheels and road.

If the car traveling at 60MPH and somehow it is downshifted into 1st gear and the clutch is let out, the impedance drops to below zero and the motor is putting out power with negative impedance and this over-revs motor and can damage, if not destroy, the motor.

Now, to take this explanation to audio systems:

The Amplifier is the motor driving the speaker.

It does this by sending electricity back and forth (audio is AC current) through a coil on the back of the speaker cone.

As the electricity moves one way (positive cycle) it creates a magnetic field in the coil, and as the electricity moves the other way (negative cycle) it creates the opposite magnetic field.

The coil is set into a magnet (the large magnet on the back of the speaker). When the coil is magnetized it either attracts or repels from the large permanent magnet depending on the input polarity. This causes the cone to move forward or backwards causing sound.

The Amplifier is designed to drive speakers of a certain impedance range, just like the Porsche motor works best when it sees a certain level of impedance.

Like the Porsche motor, if the speaker is to high an impedance in realtion to where the amplifier works best, there is a very inefficient transfer of power and the speaker's output will be low. So it is best to match the impedance to the amplifier.

Now if the Porsche is going down hill, the impedance drops and the performance will increase. This is obvious as we all know the car will accelerate faster down hill than up.

Sort of the same thing with a lower impedance speaker. You lower the impedance and you can get increased power output of the speaker . . .

However, downshift too far at too high a speed and too much impedance is removed from the motor–the car over-revs. The same thing can happen to the amplifier if you have a speaker with too little impedance.

Basically the electricity coming out of the amplifier has not thing to restrain it, nothing to push against, so the power flows too fast, "over-revving the amplifier" The electricity is flow too fast through the amplifier components. These components can over heat and damage to the amplifier can occur

Most modern amplifiers are usually built well enough that they can handle pretty low impedances.

However . . .

The rear deck infintys are 2Ω as listed on the site you linked to, so I am assuming the 92Ω is a typo in your post.

In the factory hi-fi system, which I am assuming is in your C4S, the original rear speakers I believe are 12Ω, so a 2Ω speaker may be a little low for an amp designed to drive a 12Ω load. I would be afraid to go below 4Ω for the rears. 2Ω may be OK, but there really is no way to be sure other than potentially destructive tesing. I have some 4Ω speakers in the back of my car with the factory amp and I put a couple 2Ω resistors in line to bring the load up to 6Ω just to be extra safe. I am probably being paranoid. But 2Ω is really low.

 

Here's what the manual says:

OUtput: 4 x 18 Watt
Loudspeaker Impedience: min. 4 Ω
Lineout: 4 x analog Line Out(Va max 3Veff at 10kΩ)

Price: the door speakers are $230 everywhere in canada...$90 in the states
the 4x6: $125 everywhere in canada, $50 in the states....
needless to say I am buying them from the states (ebay)

are you saying I need to "tweak" something?

 

There's a guy who's local to me (90 minute drie for you) who will give you the straight dope and knows his way around 911's. I'm happy to help if you like and put you in contact with him.

 

Amfab, thank you for the short lesson....I understand it better.
BTW, I do not have the Hi Fi option, and therefore do not have an additional AMP. It is the Hu alone that will power the speakers.....if I understand correctly, the 2OHM speakers should be fine in this case.

 

Hi,

Looks like a good match. The Traffic Pro puts out 18 Watts on each channel and those speakers can handle 40 Watts. The Traffic Pro wants 4 Ohm minimum impedance and those speakers are listed at 2 Ohm, but the note says that they act like a 4 Ohm load when operating. I'm not saying you need to tweak anything, I'm saying that Infinity says they tweaked the dynamic impedance to make it look like 4 Ohm.