ssl monoblock amp 500wrms at 4 ohms????

[sik-holden]

i bought a ssl amp thats ment to have 800 watts and 500 watts rms at 4 ohms would this amp really make a true 500wrms or is it bs?


tim

[holdenboy]

If its rated at 500wrms at 4 ohms and 14.4v then thats what it will do, the only other figure you need to take into consideration the the Total Harmonic Distortion (THD). They will give this to you as a percentage, something like 0.05% or so, obviously the higher the percentage the more distortion it has putting out 500wrms.

[1991_Vn2nV]

It really depends on whether its a certified rating or not.

SSL is Soundstorm isn't it? A cheap strathfield knock off of Soundstream. I personally doubt it will put out those ratings.

[Tasmaniak]

both the guys make a valid point...definetly check it's THD if it's 500wrms at 1% then steer clear!

500wrms @ 4Ohms is a bigger then normal amplifier.

[sik-holden]

ok it says 0.01% thd.
im just having trouble making the guy admit it dosnt make a true 500wrms. i told him about ohms law and he said its about imput power not output power.

tim

[holdenboy]

It sounds like it puts out ~500wrms, and at 0.01% THD then thats pretty much good enough for me, what about power ratings at 2 or 1 ohms, dose it state those ratings?

The only REAL way to test the output power of an amp is to put a clamp meter on the power cable cable and blow some test tones, but i'd imagine its not an expensive amp so i wouldnt be going to the trouble....how much was it BTW?

[Luke0011]

It sounds like it puts out ~500wrms, and at 0.01% THD then thats pretty much good enough for me, what about power ratings at 2 or 1 ohms, dose it state those ratings?

The only REAL way to test the output power of an amp is to put a clamp meter on the power cable cable and blow some test tones, but i'd imagine its not an expensive amp so i wouldnt be going to the trouble....how much was it BTW?

Or you could use a watt meter

[cartoonwally]

ok it says 0.01% thd.
im just having trouble making the guy admit it dosnt make a true 500wrms. i told him about ohms law and he said its about imput power not output power.

tim

How does ohms law help you prove to him that its not outputting 500Wrms? Not sure what he means by input power not output power though, not sure whether he is talking about the input power from the RCA or he's talking about some internal input power?

If the specifications say that its outputting 500Wrms at 4ohms, with the THD given, then the one that was tested for these specifications would have been. And assuming the build quality is the same as the one they tested then it will have the power given. But the only way to find out, as already suggested, is to use a measuring device on the output of the amplifier.

Also, make sure that if you do buy this amp, you drive the 4ohm load. Whats its 2 ohm load rating?

[holdenboy]

Or you could use a watt meter

True, but arent they harder to come by when compared to a clamp meter (current)?

[the_random_hero]

ok it says 0.01% thd.
im just having trouble making the guy admit it dosnt make a true 500wrms. i told him about ohms law and he said its about imput power not output power.

tim

It is. Drawing 10A at 14V doesn't mean it's going to be a 140WRMS amp.

[Luke0011]

well 10 amps at 14 v equals 140 watts according to electrical theory.

[Tasmaniak]

dont forget to take into account the effiency of the amp...or lack there of.

[sik-holden]

it only states the 4ohm load.

where would i be able to get it tested, i just upgraded to a 2 guage power cable and i seams to be alot better from the 8 guage.

my friend that does alot of amp installs said that it would make 320 odd wrms at 4 ohms but thats the imput power so my bad for that one.

tim

[Tasmaniak]

I'm trying to understand what you are meaning by input power?! The only input on an amp is 12V and line level...

As for getting it tested, why bother mate? It's an amp. If you don't like it, find another one, plenty around that will give you the power you need.

[cartoonwally]

well 10 amps at 14 v equals 140 watts according to electrical theory.

The P=VI theory works well when you are using passive components. Unfortunately for the theory we are working with active components so what is being input gets transferred completely, so you would need to take the V and I readings on the output of the amp for that theory to work (the speaker is a passive component !for all intensive purposes!).

You will find that it will draw more than 10amps when needed as well. sik-holden, can you please explain to us what you mean by "input power"? If its input power to the speakers then its the same as output power of the amplifier Do you mean input power to the amplifier?

[BrAdAsS]

Take it from somebody who has tried these amps. The Warranty return for when it dies is pathetic.
I got the Cruiser 2000.4, I can tell you there is no way it is putting out what it is rated at.

240WRMSx4@4ohm - All im running are 2x pairs of 100wrms peerless 6" splits and the gain is at 3/4.... 240wrmsx4 MY ASS! more like 140wrmsx4.

[SPLcamry]

well it won't do 500rms cause you have wire size, speaker wire, amp heatness and how long the power cable is. cause there is no way you can get a full500rms @ 4ohm.

[StoneX]

well it won't do 500rms cause you have wire size, speaker wire, amp heatness and how long the power cable is. cause there is no way you can get a full500rms @ 4ohm.

What?

[SPLcamry]

Ok say you have 4m of power wire and thin speaker wire and how hot the amp get's you will never see the full 500rms

[StoneX]

Why?

It's rated at 500Wrms, this means they measured 500Wrms on the output... As long as you have sufficient sized power cable and speaker cable, it will provide the power it's rated at.

[SPLcamry]

Yeah but when they test they don't put it in a car. They have a portable massive 300amp power suply. So i would like to see you get 500rms out of that amp with sub's hooked upto to it and running 4 metre's of power cable. My Z1 is rated at 4000rms and when i got it tested IN THE CAR it pulled 3680rms. so that blows what you say out the window

[theSeekerr]

Eeek....here we go again....

Fastest way to check would be a multimeter - whack a 4 ohm load across the terminals (I'm guessing most people don't have a great deal of 500 watt resistors knocking about, so that'll have to be a beefy sub or such), give it a nice low frequency tone for an input (say 50 to 100 hz), and then watch the RMS voltage across the load as you wind up the gain.

If that amp genuinely makes 500 watts, it should reach about 45 volts RMS.

Of course, that tells you nothing at all about its distortion, which you'll have to test by some radical method like listening to it. Many cheap car amps are poorly implemented class B designs with audible crossover distortion, something which often doesn't seem to be reflected in THD figures. If you can't hear it, don't worry about it.

As for the input vs. output power thing - it's not that hard. You can't make power from nothing, yeah?

So, let's look at the system - you've got power being supplied by the battery, and power being outputted by the amp in two forms - voltage and current through your speakers, and heat from the heatsinks.

Following our "no free lunch" line of reasoning, it follows that

Output Power = Input Power - Heat

Or to phrase it another way - if your amplifier is outputting 500 watts RMS, it's drawing MORE than that from the battery.

So, at 500 watts into 4 ohms, the amplifier is delivering 44.7 Volts RMS and 11.2 Amps to the speaker. So, with the car running, let's say the battery is at a nominal 14 Volts DC. Let's also assume that this amplifier is perfectly efficient, producing no heat at all. It'll need 35.7 Amps to maintain 500 Watts RMS.

In the real world, it'll need even more than that, something on the order of 50 amps.

Why is this hardly ever a problem in the real world? Because you hardly ever need 500 watts RMS. Running a sub with a fairly normal efficiency of 85dB per watt, you'll be reaching 112dB at one meter. Which is, in brief, very very loud.

That's not to say that a 500 watt RMS amplifier isn't useful, you need some headroom over your intended listening volume to avoid clipping.

- Chris

[StoneX]

Yeah but when they test they don't put it in a car. They have a portable massive 300amp power suply. So i would like to see you get 500rms out of that amp with sub's hooked upto to it and running 4 metre's of power cable. My Z1 is rated at 4000rms and when i got it tested IN THE CAR it pulled 3680rms. so that blows what you say out the window

You can't read...

I did say if it has sufficient sized power cable.

I'm sure this dodgy no name amp doesn't make it's rated power(because of it's build quality, not because of what you said) but you just keep saying things that don't even make sense until you're questioned about it.

Trying to produce 4000Wrms in a car draws massive current, trying to produce 500Wrms doesn't draw massive current... Most cars with decent wiring to the amplifier will have no problem supplying 50A or so to a 500Wrms amp. Whereas trying to run a 4000Wrms Class D amp at full power would draw above 350A, that's why you get massive voltage drop and don't make the rated power from the DD amp. Isn't that amp rated at 16v or 18v anyway?

[SPLcamry]

it's rated a 14.4 volt.

[StoneX]

And when drawing 300A+ you would have about 11v, if lucky, and since they don't have a regulated power supply the output power drops. It's not the amps fault that you're not giving it enough input power to produce it's output power.