ok, if an amp is a 2 channel amp, that has a rated RMS of 800x2 at 2 ohms... does that mean it is possible to wire two subs to it, and both will be getting 800 watts? or will they each be getting 400?
depends on the subs, if they are single 2ohm or dual 4ohm, they will recieve 800w a peice wow..thats an A/B amp that makes 1600w@4ohm...what model is it?
actually, I do not remember, I know I am stupid, I found once when I was on epinions.com, you should be able to find it there. so... what would it to to my subs, they are dual 2 ohm?
Here's how it works. If that amp is rated at 800x2, whether that's at 2 ohms or not, first thing I'd be skeptical of is that power rating itself. That's likely 800x2 "max power", which is a useless number. RMS power is a real rating, and that's generally half of what "max power" is, however, companies that stamp power ratings on the heatsinks of their amps ( which is generally an honest to god givaway of a flea market junk brand, dont' ask me why) are almost always "max power" ratings. What I'm getting at, is that since I don't know of any legitimate mid-grade or high-end amps that are stereo units that are rated at 800x2 (even at 2 ohms), I'd be skeptical... double check those power ratings, discover what the RMS rating is. OK, getting back on topic... Let's assume for the moment that your amp actually IS rated at 800x2 @ 2 ohms, RMS. This means the power that the amp will produce will be the following, depending on what impedance load you hook up to the amp (the speakers the amp will be powering): 400 x 2 @ 4 ohms 800 x 2 @ 2 ohms 800 x 1 @ 8 ohms 1600 x 1 @ 4 ohms Notice that the amp essentially makes it's 2 ohm stereo power, when bridged to a 4 ohm load. Take warning also that due to this same mechanism, you can't bridge an amp, and then try to run it bridged at 2 ohms... it'll go up in smoke, as it's circuitry would literally try to flow twice the amount of current that the amp was designed to handle... ...and just like having a 20 amp fuse in a circuit that's flowing 40 amps worth of current... something will melt. Except it won't be a fuse, it'll be something nice and permanent inside the amp. Now, if you have two dual 2 ohm voice coil subwoofers, that means you can wire them many ways. Think of it like this - you have four voice coils in total, between your two subs. So, you can wire things in these combinations: Bridged: Totally parallel: 2 ohms * 4 voice coils = 8 ohm mono load for the amp - amp would make 800 watts total, 400 watts per sub. Series/Parallel: Wire each sub's VC in series: 2 ohms * 2 voice coils = two 4 ohm subs Wire the two subs in parallel: 4 ohms / 2 subs = 2 ohm mono load for the amp - You can't run the amp this way, 2 ohms is too low for your amp Totally parallel: 2 ohms / 4 voice coils = 1/2 ohm mono load for the amp - You can't run the amp this way, 1/2 ohm is waaaay too low! Stereo: Series: Wire each sub's VC in series: 2 ohms * 2 voice coils = two 4 ohm subs - amp will make 400 x 2, giving 400 watts to each subwoofer Parallel: Wire each sub's VC in series: 2 ohms / 2 voice coils = two 1 ohm subs - You can't run the amp this way, 1 ohm is too low for your amp, even in stereo So, you see from this list, you've only got a few options, and none of them get you the 1600w that you paid for - ...this is exactly why impedance is so critical... You need to make sure that you are purchasing compatible equipment. Will that amp work? Sure, but it'll only put out 800w... half the power that you paid for. I've also got a concern, because it being a stereo amp means it's a class A/B amp, which will be a much heavier load on your car's electrical system than a class D amp. Class D amps are also less expensive than class A/B amps. Class D amps are usually also compatible with 2 ohm or 1 ohm mono loads, where class A/B amps are not. So, if the option is out there, I'd pass on this stereo amp.. and purchase an amp that gives you the power you want at 2 ohms, and make it a class D mono unit... in addition to costing less money, and demanding fewer upgrades and less load on your electrical system, it'll have features designed specifically for subwoofer amp duties, like subsonic filters, remote gain controls, etc. B)
well, I was pretty sure that it was RMS, but I went back and checked and that rating is RMS. I don't know why, but earlier I could not remember the amp, but now looking at it I think it is a fairly cheap amp. I am not sure if my subs will handle 800 RMS, so I figured they would not put that much out.
Rockford Fosgate Type RF X7 Car Audio Amplifier 3 Way Ready No Amplifier Type Mono Channel Brand Rockford Fosgate Bridgable Not Bridgable Manufacturer Part Number x7 Dimensions Depth 20.1 in. Height 11.6 in. Width 3.2 in. Miscellaneous Product ID 21850386 Performance Low - Pass Frequency 50 Hz - 200 Hz Power Output RMS Power at 2 Ohms 1500 W x 1 RMS Power at 4 Ohms 1000 W x 1 this is not the same amp I mentioned earlier, but I have heard these amps are rated by their max power? So would that make this figures incorrect, or is that just one of the RF series of amps? Also, is the Pheonix Gold R15.0:1 a decent amp? Would it put out is rated power?
In a nutshell, you essentially want: A mono subwoofer amp (has features like remote gain, subsonic filter, etc) A class D amp (most mono amps are class D) An amp that makes it's max power into 2 ohms, mono An amp that makes enough power to supply your subs with as much power as you wish for them Make sense?
Oh, yeah, I mean, I knew most of that, but I was wondering if the Rockford would actaully perform like that says... Oh, and how do you all feel about the Pheonix Gold
that rockford is top of the line type RF series I know someone who has an X3 and X7 heavy amps, great build quality, and he claims some of the best amps hes heard very underrated as well i wouldnt hesitate to say that the X7 puts out over 1700RMS into 2 ohms the birthsheet was around there id take the X stuff from RF over 95% of the amps out there but they cost more than 95% of them....
