Car Audio

What size fuse does this amp recommend to protect it? Friends don't let friends buy Audiobahn, Sony or think that Bose is the best evar..... The size of the fuse will tell us more about the real capabilities of the amp.

 

does anybody else here have a hard time believing those specs??? it's a $400 class D amp... yet it boasts a THD of .05%? and it only has 90amps of fuse protection yet puts out 1200w rms at 4ohms?? i dunno... I'd question it personally....

 

Boss is typically VERY overrated.
Of course, Audiobahn is typically a bit overrated as well... but probably not as much so as Boss.
In the end - who really knows, when you are talking about companies that exaggerate... who's fish story is fishier?

Let's pretend for the moment that the Boss amp will do 2100 watts (it won't), and that the Audiobahn sub can handle 2000 watts (it won't).

As you feed more power into a subwoofer, the voice coil heats up more and more. The difference in heat from 2000w to 2100w is nominal, virtually there isn't any.

But before thinking too much about that, think about what "continuous" power (aka. RMS) means.
That means an actual applied 2000w of power.
That would be a test tone, at full volume, all the time.

Real music is different... it has dynamic peaks - at which point, you might hit that 2000w of power when the bass hits. But in between hits, the amp might be putting out only 200w... or maybe 0w. Power output is proportional to volume, ultimately... and in a real, dynamic sense.

The reason people say Audiobahn ratings might be exaggerated, is because it is questionable as to whether the subs can withstand an actual 2000w of continuous power - or is it instead being able to withstand "real music", played through a 2000w amplifier?

Other, more often respected companies rate their subs the other way - conservatively.
Look at the way JL Audio rates their subs... they run them on test tones, doubling the power every hour. When the subs fail during any given hour, they cut that power in half, and declare that the RMS power rating... very conservative!

So - comparing, say, a 500w JL audio sub to, say, a 2000w Audiobahn sub... which one is really capable of handling more power?

Ultimately, it's doubtful that your Boss amp will do 2000w anyways.
And, if you are listening to real music, not test tones, that'll help protect you as well.
...Of course, a lot depends on you not having your amp clipping, having your enclosure designed properly (in your case, not too large or you risk bottoming the sub with that much power), and using a subsonic filter when appropriate (is your ported box tuned high, if ported?), or you could bottom even the heaviest duty sub on fractions of how much power it can technically handle.

Remember - there are two (and only two) ways to "blow" a sub:
1) feed it too much power - thermal failure, too much heat
2) bottom the sub out - depends on enclosure design/construction, not power. You can bottom a sub with very little power.

Hope that helps!

 

Golemon, i'm curious what exactly 'bottoming out a sub' entails... could you go into more detail on what you mean by that??

 

Physically bottoming the sub out.
Cone crashes down on the spider landing... or the tinsel leads pull taut and rip or pull... or the voice coil crashes down on the back plate... hard stop - results in hard damage.

There's only two ways to blow a sub:
1) too much power, harming the voice coil thermally
2) too much excursion, harming the sub mechanically

The first one happens simply from sending too much electricity through it. Subs come with a power handling rating on them - that's the highest amount of power the sub can handle on a continuous basis... the most power that it can thermally shed the heat from... if exceeded, thermal damage can happen.

The second one happens at whatever power level sends the sub beyond it's excursion limits - this one is a function of the enclosure design. For example, in a small box, you might not be able to get the sub even close to its output levels, even with greater than the sub's RMS rating.
In a large box, you can drive the sub to damage before you even reach the sub's RMS powerhandling rating.
And port tuning comes into play... etc.

 

boss is not overrated if you understand the ratings came

they are rated at MAX, not RMS.

no where in the specs does that amp claim 3000W RMS, is merly claims 3000w's

with the Fuse Ratings it will put out around 1200-1500w RMS (depending on input voltage) which is 3000@ max.

Boss is Target market is Flea Markets and High School Kids, so it pays them to use MAX ratings..

Kicker MTX, etc do not market to that demographic so it does not pay them to use those Ratings methods...

just a differant in marketing.