250w to little for power hx2?

[aimone 4]

ok so i have a rockford fosgate power hx2 in a 4.6cuft ported at 40hz. my saz1500 is on its way to db-r for repair. well i got this sub bnib and the only amp i've had on it is a bazooka 500wrms mono. for like 2 months it was wired at 1ohm.well the amp is only 2 ohm stable and it decided it wasnt gonna except the 1ohm load anymore. so its at 4ohm now which would be around 250wrms. i've read and heard that u can underpower subs but read alot more that that is b.s. well the sub is rated at 300-1000wrms and i've been thinkin bout this alot. well i took my ol' lady to work earlier and im hearing what sounds like sumthing againts the box rattling. my box is mounted where my backseat once was. so i look all around the box nothing is touching it. so i turn up bass i love u to try and figure it out and it kinda sounds like the sub, like a tinsel lead hitting the cone. but also kinda sounds like sumthin to do with the box. if it wasnt pouring rain id be able to check better. but anyway my question is could only 250w have hurt my baby? since it sounds like a tinsel lead slappin im concerned cause just the other day my dad said underpowering a sub can cause tinsel leads the fuck up because of distortion. i dont turn it up till it distorts either

[dem beats 1,223]

Too few watts wont hurt your sub.

You getting frisky with the gains and sending it clipped signals could no problem.

[KU40 173]

I can't believe the underpower myth is still around. It's the dumbest thing I've ever heard. How much power do you think your sub is receiving when you have your volume knob at 1? I'll give you a hint- it's much less than 250 watts. Chances are very good that it's even less than 1 watt. Is your sub being hurt every time you turn your head unit DOWN to level 1?

Check your box for air leaks. Those sound like a tapping sound from the sub when it plays.

And I'm sorry to say that your dad is very wrong about underpowering causing tinsel leads to mess up because of distortion. I don't even know how those things could be related to each other. Tinsel leads slap the cone due to excursion. If you are putting little power to a sub, unless it's in free air or below tuning in a ported box, it's not moving very much. Thus the cone wouldn't even be traveling far enough to hit the tinsel leads.

[Aaron Clinton 2,372]

This one goes up to eleven

[kirill007 52]

Love the marshall amps.

Underpowering a speaker cannot harm it.

Like KU40 said, if you put the volume down the amp will not keep sending 250 watts.

Only thing that kills speakers if u use a amp with lower RMS then the sub, is clipping.(know how to set the gains and use no bassboost, and also know where you're HU starts clipping.)

[jcarter1885 995]

Love the marshall amps.

Underpowering a speaker cannot harm it.

Like KU40 said, if you put the volume down the amp will not keep sending 250 watts.

Only thing that kills speakers if u use a amp with lower RMS then the sub, is clipping.(know how to set the gains and use no bassboost, and also know where you're HU starts clipping.)

You might want to reword that, your contradicting yourself. Having an amp with less rms then your subwoofer is not a problem at all unless you push the amp past its limits.

[aimone 4]

ok thats what i thought thanx guys.....

like i said i've read multiple yes's and no's online

yeah i think its just sumthing rattling or its the box

[Impious 1,476]

Does the Bazooka amp you were using have a subsonic filter? My guess with the limited info we have would be that you ran the driver too far below tuning and caused overexcursion.

[Duran 387]

Even if you put a square wave from a 200 watt amp on a 2,000 watt rated sub it probably won't fail thermally.

[Dan208 23]

This one goes up to eleven

[95Honda 486]

If the sub is truly rated at 1000 watts RMS, even with a 500 watt amplifier you could never blow it, even if you were a tard driving the amp into full clipping....

Clipping doesn't hurt anything anyway, it is too much power that fries a voicecoil.

People don't realize it, but alot of music we listen to (especially some rock) is heavily compressed and contains large amounts of clipped signals.

[kirill007 52]

Love the marshall amps.

Underpowering a speaker cannot harm it.

Like KU40 said, if you put the volume down the amp will not keep sending 250 watts.

Only thing that kills speakers if u use a amp with lower RMS then the sub, is clipping.(know how to set the gains and use no bassboost, and also know where you're HU starts clipping.)

You might want to reword that, your contradicting yourself. Having an amp with less rms then your subwoofer is not a problem at all unless you push the amp past its limits.

That's what i meant, i just can't write it down.(i'm from Belgium )

[95Honda 486]

Again, there is nothing wrong with pushing an amp 100% beyond it's limits (full clipping) as long as you don't exceed the continuos thermal rating of the voicecoil. A speaker doesn't know or care what waveform it is given.

Where people get into trouble is if they have an amplifier that will put out 1000 watts RMS before clipping and they connect this to a subwoofer that is rated at 100o watts RMS. When driven into clipping, the amplifier produces more power than 1000 watts (the 1000 watt rating is given when producing a sine wave) duw to the different waveform(s) it is producing. This is what causes the thermal failure, the increase in power, not the clipping. If it took 1500 watts of a clipped signal to blow the sub, the subwoofer would have blown just as fast if it was connected to a 1500 WRMS amplifer that was at full power but not clipped.....

People just forget this fact and blame every burnt coil on clipping, when in reality, it has nothing to do with it.

Think of it this way, when manufacturers rate an amplifier, they (hopefully) rate the output power while producing some sort of low distortion sine wave. Now if they rated the same amplifiers while producing a square wave the numbers would increase, they may almost double depending on the power supply..... But still, if you had an amplifier that was rated to produce a 1000 watt square wave, it would never blow a 1000+ watt RMS speaker unless the speaker manufacturer fudged the power ratings, or they were not based on real world constant power.

When you have amps that are over 1000 watts it's real easy to blow a sub. There really aren't many, if any at all, that can truly handle 1000 watts, indefinetly.... Some things heat up really slowing, especially if they have very effective cooling means, but eventually, you can almost always cook just about any sub.... And most people blame this on clipping when really, it is just not the case...

[kirill007 52]

Again, there is nothing wrong with pushing an amp 100% beyond it's limits (full clipping) as long as you don't exceed the continuos thermal rating of the voicecoil. A speaker doesn't know or care what waveform it is given.

Where people get into trouble is if they have an amplifier that will put out 1000 watts RMS before clipping and they connect this to a subwoofer that is rated at 100o watts RMS. When driven into clipping, the amplifier produces more power than 1000 watts (the 1000 watt rating is given when producing a sine wave) duw to the different waveform(s) it is producing. This is what causes the thermal failure, the increase in power, not the clipping. If it took 1500 watts of a clipped signal to blow the sub, the subwoofer would have blown just as fast if it was connected to a 1500 WRMS amplifer that was at full power but not clipped.....

People just forget this fact and blame every burnt coil on clipping, when in reality, it has nothing to do with it.

Think of it this way, when manufacturers rate an amplifier, they (hopefully) rate the output power while producing some sort of low distortion sine wave. Now if they rated the same amplifiers while producing a square wave the numbers would increase, they may almost double depending on the power supply..... But still, if you had an amplifier that was rated to produce a 1000 watt square wave, it would never blow a 1000+ watt RMS speaker unless the speaker manufacturer fudged the power ratings, or they were not based on real world constant power.

When you have amps that are over 1000 watts it's real easy to blow a sub. There really aren't many, if any at all, that can truly handle 1000 watts, indefinetly.... Some things heat up really slowing, especially if they have very effective cooling means, but eventually, you can almost always cook just about any sub.... And most people blame this on clipping when really, it is just not the case...

You forget one thing, when the sub is playing a square wave the cooiling will be less effective thus lowering thermal power handling.(but other then that i agree 110% with you.)

[95Honda 486]

No it doesn't effect cooling, in the slightest. I did a complete test on it here-

The Clipping effect test - Forceaudio

Most people don't understand this......

[kirill007 52]

Sorry 95Honda, you're probably a very smart man but you used low power drivers that don't have cooling features like most subwoofers do have.

Most subwoofers use a (sophisticated) technique to guide the air thru holes/vents to cool the coil.

They are the most effictive when used with a sine wave instead of a square (or clipped) wave.

What moves the most air a square wave or a sine wave?(which one moves the air more efficient?)

Think about a fan , if u have a fan that moves 100cu ft/min, if which will be more efficient: if the fan moves the air, then stops for a second and starts again

Or the one that keeps moving air around.

It's harder for the fan to move the air because it stopped , and the fan which moves the air all the time doesn't has the problem thus cooling more effectivly.

(this is in theory, just pure fysics, you have done a test i think noone ever did and i respect it, but it not correctly done, because you used 170hz which almost doesn't moves air, you can't apply it to SUBwoofers.)

[95Honda 486]

Like I said, some people will never understand this.....

But hey, I am not going to argue this point anymore in this thread.

Edited May 15, 2010 by 95Honda

[Duran 387]

95 why aren't you Tech Team anymore...?

[deernet 6]

Like I said, some people will never understand this.....

But hey, I am not going to argue this point anymore in this thread.

I'd like to see you explain it more. I'm interested in why the cooling wouldn't have an effect on thermal failure.

[95Honda 486]

The cooling does have an effect on thermal capacity, a very large effect in some cases. But, this isn't really effected by the waveform, this is the point I am trying to make. In my test I chose 170Hz because that was the lowest frequency that could be used that would be able to thermally fail the drivers within 1 minute and drive the speaker to its full excursion limits. At 20Hz mechanical failure set in within roughly 5 seconds at the power levels used in the test.

One of the big issues is that a speaker can't even produce a square wave anyway. It doesn't really start and stop as quickly as people think, there is ringing and dampening involved. When you get up there in frequency even a square wave has the cone moving back forth alot more linearly than you may think. Put your hand behind your pole piece driven with a sine wave and then a square wave. You can feel the same amount of air movement..... All the cooling tricks that are used still work fine when anything but a sine wave is played. This is the nature of the beast so to say...

I am not on the tech team anymore because I had asked a while back to be taken off because I didn't have the time to be on here and one jerk off in particular (not any of the staff) really pissed me off... Lol.... I am really busy and don't often have the time to be on here... I'm waiting on a flight to Afghanistan at the moment for a few days of electronic systems troubleshooting they need me to do and then I'll be back around.... I can elaborate more at that time.

-Mike