Is it Enough?

[mrwillz]

Hey, i have to Two 10" Pioneer Subs Rated at 350RMS each and im deciding at the moment to purchase a 2 Channel JVC amp 900W/200RMSX2. Will this be enough for a honda accord 95??

[EGB16A]

i'm not familiar with that jvc amp, but is the bridged output for the amp 900w RMS?

[J-MuN]

Why you buying a 2 Channel amp? Are your subs 2ohm or 4ohm? I'm assuming they will be 4ohm. If so, get yourself a Monoblock. Probably won't be as cheap as the 2 channel. Just PM me and come to see me.

[mrwillz]

bridged output is 2X200WRMS... and yes my subs are 4ohm
here is the specs of the amp http://www.jvc-australia.com/products/_products_sub_group_details.asp?ID=1406

[arverson]

ey will, if i remember correct, its these subs rite??
http://www.pioneeraus.com.au/car_entertainment/subwoofers/tsw256c/index.html

since u got 2 SVC 4ohm subs, ud want it to run @4ohm or @1ohm.
wat do u mean 'enough'?? loud enough?? 50-100rms is enough for daily/normal listening volume. 200 shud b ample for loud volumes. but knowing peter (mrwillz lil bro whos got the accord/subs) he'll prob wanna pump it to da MAX n push his subs hehehe so u might wanna consider a better, more powerful amp. how much r u gettin that jvc amp for?? pm me or holla bak on msn

[Fhrx]

While JVC is quite a good quality manufacturer, just be very careful when looking at amplifiers because there is a lot of rubbish specs out there. I've posted my article on amplifier specs plenty of times so why not once more? :-)

What amplifier specs should I look out for?

Choosing an amplifier is about more than just watts. When speaking to anyone about achieving quality music in car audio most people simply focus on the speakers rather than the amplifier. They often speak about speaker build quality and power handling, enclosures, porting, fibrefill, loading and speaker cable. You don't really need to worry about the amplifier so long as it's powerful enough right? Just like when you're considering the purchase of a new car; the only thing you need to look at is the power output of the car alone right? Wrong.

When choosing an amplifier to power your speakers there are more stats than just power output you need to think about before you splash a couple of grand on an amp that will sound like rubbish. For those among you dreading an upcoming lecture on amplifier classes, resistors, capacitors, transistors, transformers and power supplies relax, I'll keep this to plain English for the explanation of which stats to look out for. High power output is important but quality amplifiers are not just about sheer power. Mining dump trucks have over 6000 horsepower but that doesn't make them spectacular performers. Besides power there are certain other important figures that must be taken into consideration when choosing a suitable amplifier. We'll go through a few of the more commonly found stats.

Damping Factor
Damping factor describes an amplifiers ability to control a woofer cone. It's the ratio of rated load impedance to the internal impedance of an amplifier. The higher the damping factor the more efficiently an amplifier can control unwanted movement of the speaker coil. High damping factor is crucial for subwoofers and the higher the damping factor the better. It is debatable if anything over 50 is audible. Damping factor is calculated by dividing the speaker impedance by the output impedance of the amplifier. In other words the damping factor will decrease as the speakers impedance decreases. This means an amp optimised at 4 ohms will provide tighter bass than when they're running at 2 ohms. A lower damping factor will leave bass notes sounding soft and undefined, regardless of the amplifiers power output. You can see by this that a smaller 100 watt amplifier with a high damping factor can often sound better than one twice it's size with a low damping factor.

Slew Rate
Sometimes referred to as damping factor for tweeters, the slew rate describes the amplifiers ability to accurately control fast direction changes of a speaker cone or dome. Have you even turned your stereo up to discover that your cymbals sound like someone throwing a brick through a glass window? That's because the amplifier simply wasn't fast enough to accurately reproduce the high frequency ring of the symbols. Measured in volts per microsecond, a low slew rate softens the definition of a sound signal which blurs transients and causes the sound to appear muddy. A high slew rate means the amp responses faster which ultimately results in crystal clear highs.

Total harmonic distortion
THD is the measurement of the how much the amplifier can distort the sound signal through the introduction of added harmonics or overtones. THD figures are usually given as percentages and a THD figure below 1% are generally inaudible to most people. However, distortion is a cumulative phenomenon so if your head unit, eq, crossover and amplifier are all rated at less than 1%THD each, together they could produce 5%THD which may well be noticeable to most of you.

Signal to noise ratio
Noise leaking into the sound signal is an ever present problem in car audio. The Signal to noise ratio is a measurement of noise level in the amplifier compared to the level of the signal. A higher S/N ratio signifies a greater difference which is better. Technically speaking, it's the ratio expressed in dB of signal power at a reference point in a circuit to the noise information that would exist if the signal were removed (the noise floor). The maximum signal to noise ratio of the amp can be seen as a measure of realistic fidelity. This ratio is how much absolute noise it produces compared to the highest signal voltage it can pass without distortion. Many companies combat noise by utilising balanced line systems.

Stereo separation.
Separation is not spoken about much but this refers to the amplifiers ability to maintain the separation between the right and left channels. This is essentially what allows an amplifier to reproduce an accurate sound stage. Each individual instrument is after all, are recorded in it's own location in the sound stage and you should be able to hear this in the same way when it's played in your car.

Just a final few points to remember while you're looking at specs. You'll find many are followed by the term 'A weighted'. Put very simply, 'A weighting' is a way of colouring the figures a little to make them appear more attractive. Loading is another issue to consider. Watch the impedance of speakers when choosing them because while most amps are stable at low impedance levels, they're not overly efficient nor performing 100% when loaded down. Your cars engine is 8000rpm stable but it's unwise to try and keep it there for long. By the same token many amps are 2 and 1 ohm stable but this is for intermittent spikes (as music is dynamic it causes the speakers resistance to continuously change during playback), not continous everyday running. These are some of the more important figures to observe when buying amplifiers. It's not simply just a matter of buying which ever amp outputs the most power. It's a matter of taking all the figures into consideration and choosing which amplifier best suits your needs.

Hopefully that will help you in your search for a good quality amplifier. Some other brands to include in your auditions (do still include JVC) are:


Boston
www.bostonacoustics.com

Zapco
www.zapco.com

Tru-Technology
www.trutechnology.com

Vibe
www.vibeaudio.co.uk

Diamond
www.diamondaudio.com

Treo
www.treoonline.com

Crossfire
www.crossfirecaraudio.com

ARC Audio
www.arcaudio.com

Audison
www.audison.com
:D

[mrwillz]

hmm pretty cheap thats why im buying it.. $250 brand new.. well i've already got it lol.. i dont want full loud loud bass.. i just want one that will do the job nicely

[mrwillz]

Guess ill wait and see when i install it.. :D and see if it does the job! :thumbsup: