Newbie- Actual amp power

**rangerrick** · 07-24-2007, 11:03 PM

Hey people i have never delt with amps or subs before and im in the process of having them installed in my car. I do have a sony xplode amp, im told its not one of the best, but anyways im confused in the actual power her is the
specs:

rated power output:200w x2(4ohms)
max power output 1200w(2ohms)

If you guys can get anything from that please let me know, and also what would be the be the best way get the most power out of it. Thanx

**monkeyracer** · 07-25-2007, 12:05 AM

ok, here's what you have:

Rated power is what you will see at around 12v, at any random time, where the max power is at 1 ohm, 14v. This amp (and most in this competition range) is not capable of handling 1 ohm. This rating is sometimes called 'when lightning strikes' since the amount of power required to actually get this rating is more than any normal car can output. Most car systems are closer to 13v when the alternator is running.

The power that this amp will output is also dependent on how it is wired to the subs, and such.

For example:
If you have two dual 2 ohm voice coil subs, wired in parrallel, then into one channel each, you would have a 1 ohm load, but probably blow the amp, wired the voice coils in series, and you'd have a 4 ohm load on each channel, and you would get 200w in each sub.

The best configuration for this amp is two dual 4 ohm voice coil subs (or two single 2 ohm voice coil subs, but these are less common). Wire each voice coil in parallel to net a 2 ohm load for each sub, and wire one sub to one channel, the other sub to the other channel.

Make sure they do not share any common air space in the box. This will give you 250W per channel on average, net of 500w, and when a good bass line hits, probably near 350w or so per channel, net of about 700w. (estimate) You'll also have more surface area to move air than if you have one sub bridged at a 2 ohm load.

I had the older version of this amp, and it was just fine, except mine would cut out after a while playing full volume. I put fans on it, and it helped, but not a lot. It will do just fine unless you are planning to put it at it's full potential all the time.

Terms:
Ohm - Measurement of the resistance of electricity.
Watt - Unit of electrical (and other) power measurement.
Series - raises electrical resistance, decreases power output.
Parallel - lowers electrical resistance, increases power output.
Bridged - Wiring one sub (or set of subs) to both channels together to bridge the power between the channels.

One thing to keep in mind when you get to tuning the amp is that the gain is not designed to be a volume adjustment or bass boost. It's designed to match the input voltage to optimize the output. Meaning my Pioneer Head Unit's sub-out has a pre-out voltage of 4v, so I would tune my gain to match this, not above, and not below. It's tempting to turn the gain up, but this may provide some distortion, and reduce the amp's life span. You should be changing volume settings through the deck, and not on the amp.
Also, set the cut off frequency (low pass filter) to around 150hz - 250hz, depending on the subs you use, and what other speakers are in your system.

Hope this gives you a good start with this.

There are LOTS of pages, threads, posts, whatever related to this.
Just search through, and I'm sure the answer is somewhere, since someone has already asked almost every single question you have about this.

**rangerrick** · 07-25-2007, 06:50 PM

THanks man. Lot of the info you gave is very helpful. Seems like you have a lot of knowledge about this subject. So..... how would you rate the amp i have? I like alot of bass And i have 2 12inch Rockford Fosgate Punch Subs. Im not too sure about the specs other than They are 4ohms each.

**monkeyracer** · 07-25-2007, 08:20 PM

your set up will give you some decent bass. nowhere near competition levels, but i'd be willing to guess around 130 to 135 dB depending on the box. with your subs you aren't maximizing the potential pof the amp, but that's ok. At full potential, this amp will not last long. You are probably getting the 200w advertised on each channel, which should be plenty for these subs. Just mae sure the box is built right: it has to be solid and airtight, and of course the correct volume. subs with a lot of power from the amp in a badly built box, won't sound as good as lower power in a well built box. My brother now has my old sony amp, it's 3 years old and still kicking.
if you want a little more bass, see if you can exchange them for the P2's in a dual 4 ohm voice coil. it will be a little more money, but you'll get more out of the amp.
the only way I know as much as I do, was asking questions.
BTW, who is building the system? you or the car audio shop? are they making the box or prefab?

**rangerrick** · 07-26-2007, 07:19 PM

My Subs are pre fab and i am having a shop install everything for me. I am also having all my factory spaeakers replced, im thinking Boston Acoustic....... good choice or not??????????? Also i found the specs on my subs on the internet, my subs impe are actually 8ohm.

Description Value
Woofer Quantity 2
Woofer Size 12"
Woofer Series Punch Stage-2
Woofer Impedance (ea) 2 x 8-Ohm
Power Handling 400 Watts RMS
800 Watts Max
System Configuration Ported
Enclosure Material 5/8" MDF
Speaker Connector 4 AWG Binding Post
Shipping Weight 74.0 Lbs.
(33.6 Kg.)
Dimensions 15.5 x 34.0 x 16.5 (in)
39.4 x 86.4 x 41.9 (cm)

http://www.rockfordfosgate.com/produ...n_US&p_status=

**kostyanj** · 07-28-2007, 04:37 PM

If you like a lot of clean bass, I would stay FAR away from RF subs. They put out some of the most distorted bass I've ever heard. No matter the enclosure or the amps powering them. They just use cheap components in the manufacture of them. Spend a little more money and go a litter higher on the scale. Even an Alpine Type S is a little more money but it'll sound much nicer.

Good luck on your install.

**monkeyracer** · 07-29-2007, 12:55 PM

Boston acoustics makes some good speakers, at least when I used to sell them a few years back.
I really hate pre-fab boxes, you just paid $500 for something you could have made for less than half the price that would probably sound better. You really paid for the convenience of not having to build it yourself though.

RF are not SQ subs, for damn sure. They are getting better, but they are still not up to the quality standards that most other companies are at. Pioneer, infinity, alpine, all make decent low end subs. I think for your situation, you are looking for the quick fix of a pre-fab system, check this out:

Pioneer Premier 12"
http://www.pioneerelectronics.com/pn...510778,00.html
Pre-fab box for it:
http://www.pioneerelectronics.com/pn...076561,00.html

$450 for the two together means you would have had a little money left over. Sure it's one sub vs two, but these are way better quality, and would have got more power out of the amp.
If you got the Dual 2 ohm version, wired in series it would show a 4 ohm load on the amp, (bridged into monoauraul operation,) you would be putting 500w continuous, and up to about 800w - 1000w max into it. You would get more SPL (easily over 140dB) and a lot less distortion too.

If you can, see about getting it exchanged for this set up, you'll definitely like what you hear. If this shop doesn't have premier (high-end shops will) then go to one that does.

**rangerrick** · 07-30-2007, 11:10 PM

Thanks again for the info. Im really thinking about swiching the subs. Im definetly exchanging my amp. I was also offerd by the shop installing my system, sound proofing of my trunk. I drive a 2000 buick century and it has good trunk space. Do i actually need to sound proof my trunk?