JL 300/4 vs Alpine MRV-F545
I have torn apart choosing amps right now need some suggestions and guide lines. Between these two amp from what i understand
JL 300/4 (about $370 from ebay)
Pros:
- Fit in blose amp location
- better sound quality
- has a more stable power supply?
Cons:
- Expensive
- Less listed RMS per channel

Alpine MRV-F545 (about $340 from ebay)
Pros
- Cheaper than JL
- more RMS per channel
- New design
Cons
- does not fit in blose amp location from my understanding

or even the older Alpine model MRV-F540

And the amp is going to power my front MB quart PCE216 components and a 10" sub that im decide soon. And for the sub i have to bridge the rear channels to power it, and i have a question about which ohms do i need for the sub? Coz since i bridge the rear channel dont i need to get a 8 ohm subwoofer?

Sorry this post might be really annoying to someone but ...im really confused right now.

 

Help please

 

jl is the winner sound quality and don't look at rms the rms for alpine is at a 14.4 volt rating hardly ever achieved on a constant the jl is pricer but its because of its technology to always run at that 14.4 volt rating day or night i.e lights on. i have a alpine v12 four channel in my civic that is great but for the G35 im doing the jl route i have a audio nut friend like myself who has the same set up as me in my civic and switched out the alpine for the jl and you can hear the diffrence on those tracks which really display a wide range of sounds.

 

Well for 30 bucks more? go with JL, so you dont have to worry about what ohms of sub you gonna use, cus it give out same wattage between 3~8ohms, I would suggest that you looking some amp have bit more power for the subs, 150 just dont seem to be adequate! instade of 300/4, maybe 450/4? bit pricey tho , most of amps when you bridge them, it will only be at 4ohms, so you are looking at either 1 10 4ohm or 2 10 8ohms, or you can get dual voice ones, the dual 4ohms will give you more flexabilty later if you decide to add second subs or mono amps

 

JL Audio

 

I feel your pain I did my own car a few months ago and it took some time to figure out what's best. I don't know anything about the Alpine but I will tell you what I know about the JL since I have three of their amps. The 300/4 is stable from 1.5-4 ohms, not 8. It is nice because you can get pretty much any sub and make it work. If you get a dual voicecoil sub you have the choice to hook it up in either serial or parallel. In my case I bought a 10" W6V2 with dual 4ohm voice coils, so the choices are either hook up the Dual voices coils in parallel at 2ohms, or hook them up in series at 8ohms. 2ohms will get you more volume, 8ohms will get better damping. Now the JL is only stable up to 4ohms so every time you double the ohms you half your power. That would mean you only have and effective 75watts driving the sub at 8ohms, which is not enough power. So your only option would be 2ohms witha 4ohm Dual Voice coil sub. Now you can get other subs at different ohms. Just look at the voice coil ohms and do the math if they are DVC (Dual voice coil) to see what you end up with. Most manufactures are making DVC subs because you have many more combinations when hooking multiple subwoffer togther. 2 8ohms subs in parallel = 4 ohms, so you have many more options with upgrades and or better resale valuse with DVC sub. I hooked my sub up in series at 8ohms but I have a JL 500/1, I like the precision of the damping over the loudness of 2 ohms but I have the power to spare. 2ohms at 500watts was really loud.
I would aggree a 300/4 is marginal on power your only getting 75 watts per channel up front and a 150 bridged to the rear. A 450/4 would be better in your application if you can afford it. I don't think a 300/4 would be bad but I have a 300/2 driving my front components and I can drive them till they clip and still want more. However you can always upgrade later, by moving the 300/4 to just drive the fronts 150 per side and upgrade the subamp. I built my system in stages and if you plan ahead it works well.

 

Not to nickpicking but... ...it isnt right, the amp is stable to 8, if an amp is stable to 4? it will take 8 ohms or more, it can go higher, but not lower from the lowest ohm rating, well you could but it wont last very long, but you are right about the wattage been less if you go higher ohm load, just like the oppsite of lower the ohm load higher the power output......got this from JL's website....



Specifications:

Rated Power (stereo):
75 W RMS x 4 @ 1.5 ohm-4 ohm
(11V-14.5V)

Rated Power (bridged):
150 W RMS x 2 @ 3 ohm-8 ohm
(11V-14.5V)
THD at Rated Power:
<0.03% @ 4 ohm
S/N Ratio*:
>108.5 dB below rated power
Frequency Response:
5 Hz-30 KHz (+0, -1dB)
Damping Factor:
>200 @ 4 ohm per ch./50 Hz
Input Range:
switchable from 200mV-2V RMS
to 800mV-8V RMS
Dimensions:
13.4"L x 9.25"W x 2.36"H

 

You guys are forgetting that when you bridge most amplifiers, it operates at half the resistance its given. So in this case if he bridged the rear to channels and put an 8 ohm sub on the amp, it would operate at 4ohms. But since JL Audio amps used regulated power supply the output from 1.5-4 ohm is the same, just like someone else here stated. Since you're not going to get a lot of power for the sub from this amp, I would suggest the JL 10W0 8ohm or 4ohm.

 

wow thanks for the input guys...so JL 300/4 it is...yea i have been looking at the 10W0 4 ohm...and possibly the new 10W1 4 ohm...

 

If you think there is ever the possibility of adding a second sub to the car get yourself a 8ohm woofer.

 

I use a 300/4 for my 4 sets of components, and a bridged 300/2 for my sub. It sounds fantastic. I like the sound of rear fill, so for me, doing only one set of components was not an option. I use an 8W7 sub, and even with a small sub like that, the 300 watts of the 300/2 is considered optimal. So using half of a 300/4 will defiantely not be enough power, no matter what sub you choose. If you are going to use a sub that is bigger and more power hungry than the 8W7, you'll probably want even more power than the 300/2 I am using. On JL's web site they have a chart that shows the power range and optimum power for each of their subs.