I have spent a lot of money on upgrading sound systems in cars my WRX is loaded right now but a simple question. (I hope) Can you replace the Bose speakers with focals all around without changing the amps? I know the Bose speakers are crap but are tuned using a built in equalizer. Can the Bose amp handle the focal speakers without crapping out and how do you think it will sound using the Bose settings for equalization?

Thanks
Arnie

 

Great question! I have focals in an Alfa that I want to swap with the bose speakers. Can you just do a switch?

 

excellent question...since I can not change my amp due to MOST on 03 cars I was thinking of just upgrading the speakers to focals and maybe change the sub to JL...

 

I would have to say NO. Most of the BOSE stuff runs on a 2ohm setup and the focals will run at 4ohms. I am sure you can replace the speakers but the volume level on the deck will need to be turned up to compensate for the lack of power. I would just add an amp the bose Amp will not do the Focals justice. I would recomend Zapco and audison amps. Focal runs the audison amps in the demo cars at the CES show in vegas.

 

Ysitsmn
I'm not sure I follow you. A 4 ohm load is much easier to drive than a 2 ohm load (the 2 ohm load requires much more current). So, if they do not have built in equalization (that would be a problem), the bose amps should easily drive the higher ohm speakers if the speaker efficiencies are roughly comparable.

I would love to do the same thing. While the speakers are not terrible, the bose subs really are bad. I will be probably be happy if I can just replace the subs.

 

If you are running an amp that is 2ohm max output then if you run a diffrent ohm load you will cut down the actual power from the amp. The bose amp is not near clean enuf to run to the focal speakers and really enjoy them.

 

So what you are saying it is the amp is the problem. The amp output is only two ohm. But as Color Change says the speakers should play louder. So are you saying is that the amp will not do the Focals justice but I still do not understand why the speaker volume will have to be turned up. A 4 ohm speaker will play louder than a 2 ohm speaker because it is easier to drive. What about the MB-!uarts? Thanks
Arnie

 

The speakers may not play louder, that would depend upon the efficiency of the speakers, but a higher ohm speaker is easier to drive than a low ohm speaker because the current demands are less. This is where most amps struggle (outside of distortion, frequency response, …). I am not sure what YSITSMN is talking about.

 

The speakers may not play louder, that would depend upon the efficiency of the speakers, but a higher ohm speaker is easier to drive than a low ohm speaker because the current demands are less. This is where most amps struggle (outside of distortion, frequency response, …). I am not sure what YSITSMN is talking about.

 

2 Ohms is less resistance than 4 Ohms meaning less power needed.

 

Wardhog, sorry, you're confused. Power is expressed in watts. A 100 watt amp will require 5 amps of current at 4 ohms. At 2 ohms, the power requirement is 7 amps, and as I said earlier, this is difficult for amps and causes clipping, distortion, etc.

 

Actually, the wattage is a lot lower when you calculate with 12 volts DC using Ohm's Law. Now, I imagine todays stereo amps have built in power boosters to accommodate the 12 volt system. If you use 12 VDC with 4 Ohm you'll have a 3 amp current draw with a total to about 36 Watts. Now with 12 VDC @ 2 Ohm's you'll have a 6 amp draw with a higher wattage output of 72 Watts.
About amp clipping, couldn't you use a higher Watt rated speaker?

 

Wardhog:
Yea, you're right, I assumed 120 volt but your calculations prove my point, current requirements go up as resistance (ohm’s) go down. High current is hard for amplifiers (expensive transformers, capacitors, …) and often defines the good from the bad.

The watt handling ability of the speaker will be before the speaker itself distorts (overheating the voice coil, running out of voice coil travel, ...), assuming you have the amp to drive it.

The bottom line, if Bose are really 2 ohm loads (I don’t know), and if they are normal efficiency, going to an 4 ohm or even 8 ohm load should be quite possible, just as long as equalization isn’t built into the amps, i.e. Focal's should be easier to drive if the efficiencies are comparable.

 

Color cHange is correct.

I had 2 Adcom 300 watt amps to drive my Infinity Gama speakers. Iwould keep on blowing my drivers. Infinity told me that the wattage was not important but the current. I went to 1 Krell amp at 100watts a channel and the other Krell was 80 watts a channel and have never had a problem since. My Krells put out about 50 amps of current while the Adcoms basrely reached 20 amps. So a 4 ohm/8ohm speaker is easier to drive than a 2 ohm speaker.

Arnie

 

Ok OK.. If you are running amp in sterio at 4ohm and parallel it down to 2 ohm you will get more power out of the amp if it is 2ohm stable. But in Bose amps the amp is 2 ohm and not 4 ohms stable. So when you introduce the 4 ohm load to the base amp you will loose half of your power. Another thing to remember is that the crossover Freq is usally in the bose amp and not at an actual cross-over. I f you are planning on running the focals of of the Stock bose amp will be under powered and sound like crap. Your best bet is to run a seperate amp to you speakers.