I've read that alot of people replaced thier factories with the Kappa's which are 2 ohms and had good results . I have a set of 4 ohms laying around and was wondering if it would put out bad sounds.

I used to have an Acura TL with the factory Bose system that I replaced the crappy stock speaker with some Walmart special- Lightning Audios(4ohms?) speaker and it sounded soo good. Now Im not sure if the TL had 2 or 4 ohms. Just wondering if it would be the same for G's before I go through all the trouble making the MDF spacers.

 

The volume will be quieter. I guess it could burn out channels on the amp too, but I think it's more likely that it will just be much quieter for any given volume.

 

The "BlOSE" system is our cars is really just a bose amp and sub. The HU is clarion and the speaks, other than the sub, are standard Nissan parts. 4 ohm speakers. I have an alpine amp running all 4 of my speakers on 2 ch in parrallel. If they were 2 ohm speakers, the amp would see a 1 ohm load and pop. But it runs fine. 4 ohm replacements should be fine. Not sure about the whole Lightning Audio thing. To each there own I guess.

Good Luck.

JH

 

All of our cars are a bit different, meaning if you have a sedan vs a coupe and blose vs non blose...

Non Blose Coupe - 4 speakers - 6.5 components up front and 6.5 coaxials in rear sides. No amp.

Blose Coupe - 6 speakers - 6.5 components up front, 6.5 coaxials in rear sides, and 6x9s on rear deck lid, all powered by Blose Amp. Funny too because it takes in 4 speaker inputs and outputs six, and does all the conditioning. Basically it really BLOSE!

Blose Sedan adds the 8" sub. However, this is self powered, not part of the amp.

Note: The Blose Speakers are 6x9, the other four are still Nissans.

Ok so anyway, Yes the Blose system uses 2 Ohm speakers. Why? Because it takes less power to drive them than a 4 Ohm system. Ohms law... V = IR... some basic algebra, P = VI, so P = IIR.

Anyway, what this shows you is that you increase the resistance level of a speaker and you increase the power required to drive it. So if you have ever looked at an amp manual you will note that an amp capable of doing 100Wx4 RMS at 4 ohms does like 140Wx4 RMS at 2 ohms. Why? Because it takes less effort to drive a lower impedance speaker.

So again, Blose put in 2 ohm speakers to be cheap so they could come up with a weaker amp and still make it loud. Simple as that.

I have read that many people are very happy with the Infinity Kappas (2 Ohm speakers) as direct replacements for what Infiniti charged you through the nose for in the rest of your car. The low 2 Ohm impedance makes them easier for your Blose amp to drive to higher volumes despite the higher power requirements. Although the Blose amp is a piece of junk and does a lot of sound conditioning that is better left to an aftermarket HU, so I recommend getting rid of it.

Sure put in your 4 ohm Walmart speakers, but I'm suprised you think they are better. Since they probably don't require much power to get loud, it may work just fine.

 

"Ok so anyway, Yes the Blose system uses 2 Ohm speakers." Inno

How do you know, Are they stamped with the ohm rating? Does anyone have a picture?

JH

 

from what i remember el duderino saying the stock bose speakers are in fact 4 ohm, with that in mind you would not see a decrease in volume. I have not taken my speakers out yet to verify this for myself, but based on what i have read from el duderino i would believe him. He is full of very good info

 

no, they are 2 ohms. if you do a search someone actually measured it

 

why cant you use the stock spacers?

 

the speakers in the 04(?) and above I believe have the "spacer" built into the speaker. They are funky lookin too...

 

i c.

 

By the way, even if you replace a 4 ohm speaker with another 4 ohm speaker, if the new aftermarket speaker has a higher wattage rating (which it will), then it will most likely require more power to get loud. So, you will see a drop in volume regardless.

 

WTF? You assume a fixed current source. Okay, how about a fixed voltage source? V = IR, P = IV, so P = V^2 / R. Now power decreases with increasing resistance.

How "hard" it is for the amplifier depends on the amplifier drive circuitry. Generally higher impedance loads are easier on the electronics to drive since the signal damping is higher.

 

NOW you are making assumptions. Take a look at my comment below where I talked about amp manuals. Go pull out any amp manual, and you will see they all deliver more power at a lower resistance. I.E. Power needs go up as Resistance goes up, OR another way to look at that is your inverse relationship, The actual power of the amp goes up as the resistance of the speaker goes down. I was just trying to keep it simple. Either way you slice it, it says the same thing.

P=IIR ---> You need more power to drive more resistance

P=VV/R ---> As you decrease the resistance of the speaker, the amp power increases

At the end of the day, they all say the same thing. Books can tell you so much, but real world experience is what speaks here. Go try the experiment out yourself.

 

I'm not sure where your EE knowledge comes from, but you seem to be a bit confused. Your comments don't even make sense. "You need more power to drive more resistance"? We're comparing driving a set amount of power in to varying loads. From a theory standpoint:

P = IIR: As you decrease impedance, you need to increase the current to maintain constant power.

P = VV/R: As you decrease impedance, you need to decrease the voltage to maintain constant power.

In the real-world situation in a simple amplifier, there is voltage-based current sense feedback for regulating the load (the speaker). Simple amplifiers that don't detect the speaker impedance need to be told what the actual speaker impedance is so it can correctly regulate the output for the power rating and settings.

Let's say that you have an amp rated for 4 ohms hooked up to a 4 ohm load, and the level settings are set such that it drives a current through the load with a feedback voltage of V across the load. The current going through the speaker is I = V/4. The power delivered to the 4 ohm speaker is:
P = VV/R = VV/4, or equivalently:
P = IIR = (V/4)(V/4)4 = VV/4

Now let's say you replace the speaker with a 2 ohm load (without telling the amp, or using an amp with no load selector for power regulation). Again the amp is looking to generage a feedback voltage of V. Now the current through the speaker is I = V/2, which is twice the current that was passing through the previous 4 ohm load. The power delivered to the 2 ohm speaker is:
P = VV/R = VV/2, or equivalently:
P = IIR = (V/2)(V/2)2 = VV/2

So decreasing the load without telling the amp results in increased power. Increasing power levels delivered to a speaker generally result in increased sound pressure (louder). However with more sophisticated amps that have selectable loads or load detection, they internally change the feedback to deliver constant power for a variety of loads.

As far as "ease" of driving a load, that's a hard thing to define. But if we assume one means stability of the output and how well it tracks the input signal, higher impedances are better. If your amp can put out the power you need in to the higher impedance load, go with that.

 

You need to learn about amps. Nothing is constant in a car, and your assumptions are wrong. The power is not constant and thats why you don't understand the concept. As I stated, when you connect an amp capable of driving different impedance speakers, the output power of the amp outputs actually changes. Take a look at the amp manual. They will say things like 100Wx4 at 4 ohms or 140Wx4 at 2 ohms.

Next you should review your EE books and learn about RMS power some more, because it doesn't double as you were suggesting. It is RMS (Root Mean Square) power that is important here. Square root of 2 ~= 1.4

Regarding "you need more power to drive more resistance," I will spell it out for you. Two similar speakers, one 2 ohms, one 4 ohms. Put them on the same amp. The 4 ohm speaker will require you to turn the volume up more to get the same loudness as the 2 ohm speaker did.

It's really a simple experiment. Stick 2 ohm speakers on an amp, and stick 4 ohm speakers on an amp. Tell me which is louder. It will be the 2 ohm speakers. The reason? Because as we both indicated... P=II/R, you decrease the resistance and the power goes up (just like I mentioned above with the amp manual example).

So the even simpler way to look at it, as I have stated is that if you increase the impedance of the speaker, you will have to increase the volume to get the same loudness.

I'm sorry that your EE degree didn't teach you this. Maybe I learned that while I did my MSEE? Oh I forgot, I didn't learn this $hit in school. It is real world applications. Sometimes you can't learn everything from a book dude. Just go try it. Respond as you wish, but I'm done with this thread.