Extremely Disappointed

[walled01alero 2]

What were you wired to on the saz when this happened?

[ford302redneck 15]

I still don't understand why the OP didn't hear,see or smell any warning signs.

Burning voice coils usually give warnings they are under to much of a load.

[holley2346 6]

Id like to follow up and let everyone know that the amplifier was at fault. I appreciate you pointing out the amplifier nick, I hooked everything up last night and sub was getting stinky at extremely low volume. I checked the output and was receiving a steady 51 volts dc. I'm hoping I haven't burnt up my other sub now.

Also note fi was very helpful in providing a recone and I really apreciate their assistance.

[onebadmonte 235]

Id like to follow up and let everyone know that the amplifier was at fault. I appreciate you pointing out the amplifier nick, I hooked everything up last night and sub was getting stinky at extremely low volume. I checked the output and was receiving a steady 51 volts dc. I'm hoping I haven't burnt up my other sub now.

Also note fi was very helpful in providing a recone and I really apreciate their assistance.

Bummer hearing that. Glad you got it worked out though.

[Duran 387]

Sounds like full DC rail, bummer

[raolito1980 2]

Damn that sux. Hopefully your other sub didnt suffer.

[95Honda 486]

Id like to follow up and let everyone know that the amplifier was at fault. I appreciate you pointing out the amplifier nick, I hooked everything up last night and sub was getting stinky at extremely low volume. I checked the output and was receiving a steady 51 volts dc. I'm hoping I haven't burnt up my other sub now.

Also note fi was very helpful in providing a recone and I really apreciate their assistance.

You know what is lame about this, you perpetuated a stupid myth because you didn't know how to check your stuff out. This is what is bad about internet forums...

[jcarter1885 995]

Id like to follow up and let everyone know that the amplifier was at fault. I appreciate you pointing out the amplifier nick, I hooked everything up last night and sub was getting stinky at extremely low volume. I checked the output and was receiving a steady 51 volts dc. I'm hoping I haven't burnt up my other sub now.

Also note fi was very helpful in providing a recone and I really apreciate their assistance.

You know what is lame about this, you perpetuated a stupid myth because you didn't know how to check your stuff out. This is what is bad about internet forums...

x2, thats why we tell everyone to double check everything even if you think its hooked up correctly or you think it is working correctly. Glad you found out what it was before throwing more subs in there and causing more damage.

[SubSam 21]

This is the first sub I have ever "blown"... it just seems odd that even though it's blown, it is still showing normal resistance

Props to Fi for making quality coils, nobody says the copper (or whatever) has to burn before it melts stuff, if its good quality.

That's a melted 60 amp fuse holder with the fuse in tact that ran my power inverter and a minifridge for an hour... what temp does that thermoset plastic melt at?

What M5 was getting at is that maybe you all don't even know what clipping even means beyond a square waveform in your mind's eye, but really the subject at hand is distortion. Before I continue I will say that 99.99% of the time if you blow a woofer, its the amps fault, whether by receiving inadequate power support or having incorrectly adjusted the levels or you flat out misaligned your amp to your woofer. So, back to clipping:

Amps are rated at a given total harmonic distortion at a corresponding load, ie 2000 watts at 1 ohm WITH .1% THD. The same amp, at higher distortion but same load, may look like 3150 watts at one ohm with 10% THD. Now distortion is basically any imperfection in the sinal waveform, typically 'squaring'. The more its non sinal, the higher the THD. Obviously in this case you probably had not only a gain level issue but some voltage drop and a resulting distorted mess, pumping ugly chunks of way overpowered sloppy signals through the vc until the glue quit.

Now are you comparing the sound of two neo BtLs on 1500 each to the sound of one gen 2@3000watts? I ran my gen 2 at 2400 watts, now my neo BtL at 2230, almost identical boxes and the neo is very very similar, tho a different car. Comes alive at much lower volume, kick drum has extra oomph (slightly), but I can respect your opinion. Mine differs, however.

[95Honda 486]

^^^ Ughhh, no. The type of signal doesn't effect VC failure..

But it is like beating a dead horse....

[SubSam 21]

I'm not talking signal, I'm talking amplifier output. I am agreeing with you that "clipped" (inappropriate term but anywho) signals can not break a woofer, without excess power, which could tear apart a coil without a clipped signal. And I won't venture further into woofers, as I don't know much about them except the obvious; I was talking strictly amplifier failure, I'm not into building woofers, but amps, mmhmmm

But I really can't dumb it down enough, if anybody really cares buy an dual analog/digital amplification textbook, might wanna brush up on fields and waves if ur calc is rusty... pay attention to signal propagation under distortion, which is one of the easiest scenarios to model mathematically (obviously), and watch what happens when you compare the power OUTPUT of the amplifier with a high uncertainty (non linearity), to what it should look like. And model the phase plot while ur at it, its ugly to say the least.

I can hopefully post a graphic when I get home from work, basically the amplification can fail in a way that the signal is totally non-sinal, and the slower the recovery of the electronics, the greater the currents through each component (Just like low Hz LRC circuits). Current doubles, heat dissipation quadruples. That's some V=IR stuff right there.

I'm just trying to explain how his amplifier failed, so nobody blames the sub. my N2 is my new baby.

[NDMstang65 403]

I'm not talking signal, I'm talking amplifier output. I am agreeing with you that "clipped" (inappropriate term but anywho) signals can not break a woofer.

Going to disagree with that.

When I have time or when Scott has time we'll make a graph with what we found.

Power is power..but what isn't being considered is your time value of a 'square' or 'clipped' wave over the cycle period. You are at the extremes of the wave form MUCH longer which induces a significant amount of more heat to build up...which..kills the sub.

Seen there...and below in the following 3 images. Yes the 'power' is 'power' and 'watts' is 'watts'...but you are not considering it over a given period of time where the coil is literally standing still burning and then immediately slamming in reverse and standing there and burning until it gets slammed forward by the fets. It is like trying to change gears without pushing in the clutch while traveling 70mph forward and 70mph rearword. Clipping...induces a SHIT ton more heat over this period of time..the heat and the coil bouncing off of the switching frequency of the output transistors..causes it to melt.

[onebadmonte 235]

I've visualize it as connecting a battery directly to the speaker. That clipped/squared wave at it's peak is direct current. A double "A" battery is going to do much to a subwoofer, but connect your car battery to your sub and watch the sparks fly.

[oldsboomer 1]

Thank you for coming in here Nick. You said exactly what was going to. The coil moving within the gap and having forced and compressed air constantly moving around it is what cools the coil. When you "clip" and the coil stops(you cant visually see it but watch it on a scope) the heat builds up exponentially due to no air movement. Granted yes there is air in the gap surrounding the coil but its not pressurized and in motion. The air being compressed is colder (dont believe me fill a compressor with air and about 30PSI and open the release vavle and feel the air temp) then the ambient non-compressed air. So yes "clipping" does kill the sub due to heat

[SubSam 21]

I'm not talking signal, I'm talking amplifier output. I am agreeing with you that "clipped" (inappropriate term but anywho) signals can not break a woofer.

Going to disagree with that.

When I have time or when Scott has time we'll make a graph with what we found.

Power is power..but what isn't being considered is your time value of a 'square' or 'clipped' wave over the cycle period. You are at the extremes of the wave form MUCH longer which induces a significant amount of more heat to build up...which..kills the sub.

Seen there...and below in the following 3 images. Yes the 'power' is 'power' and 'watts' is 'watts'...but you are not considering it over a given period of time where the coil is literally standing still burning and then immediately slamming in reverse and standing there and burning until it gets slammed forward by the fets. It is like trying to change gears without pushing in the clutch while traveling 70mph forward and 70mph rearword. Clipping...induces a SHIT ton more heat over this period of time..the heat and the coil bouncing off of the switching frequency of the output transistors..causes it to melt.

Lots of people probably think an amplifier pumps a dc current back and forth at a given variable frequency. It's not like that at all. These people belong on the team that built that mechanical MTX woofer (tards).

One thing in terms of amplifier topology I should have mentioned is the nature of digital processing, which is evident in the majority of most amplifiers these days. The beauty of the digital design is that any waveform can be broken down into pieces, almost unlimited times, and processed "piece by piece" if you will, which also becomes one of the design flaws. The square waveform above, if looking at the two 'corners' of the wave, is basically a dc current running hard through the coil. Obviously not good for the vc. What separates good amplifier processing from bad is a frequency sensitive regulator. The INPUT signal, if square (100%), can still be processed as a normal sine. In square, out round. If you are talking strictly input signal, then I'm not on the same page. With a poor amp (with analog or simplistic digital topology), at very low power (less than thermal limit), a dc current through the vc won't kill it, depending on the ratios I suppose, and may lead to mechanical failure, but can't really be a definite "coil killer". Especially since apparently Fi uses great materials for their winds. But when you start to add extra power and square waves then you got definite problems.

Lesson: Buy good amps dammit, that HiFonics POS is only gonna get you laughed at. Pm me and I will turn your HiFonics to a Stetsom, for a price

[SubSam 21]

Instead of averaging the two points from each corner, and creating a sine from the average amplitude, my first attempt managed to turn the clipped portion of the sinal into a 15kHz wave... I called it the bass whistle, it was pretty funny, but very power inefficient, and obviously not what I was going for. I've learned so much about digital design since then lol.

I'm still waiting for a magnetics lecture from you Nick

[NDMstang65 403]

Lots of people probably think an amplifier pumps a dc current back and forth at a given variable frequency. It's not like that at all. These people belong on the team that built that mechanical MTX woofer (tards).

One thing in terms of amplifier topology I should have mentioned is the nature of digital processing, which is evident in the majority of most amplifiers these days. The beauty of the digital design is that any waveform can be broken down into pieces, almost unlimited times, and processed "piece by piece" if you will, which also becomes one of the design flaws. The square waveform above, if looking at the two 'corners' of the wave, is basically a dc current running hard through the coil. Obviously not good for the vc. What separates good amplifier processing from bad is a frequency sensitive regulator. The INPUT signal, if square (100%), can still be processed as a normal sine. In square, out round. If you are talking strictly input signal, then I'm not on the same page. With a poor amp (with analog or simplistic digital topology), at very low power (less than thermal limit), a dc current through the vc won't kill it, depending on the ratios I suppose, and may lead to mechanical failure, but can't really be a definite "coil killer". Especially since apparently Fi uses great materials for their winds. But when you start to add extra power and square waves then you got definite problems.

Lesson: Buy good amps dammit, that HiFonics POS is only gonna get you laughed at. Pm me and I will turn your HiFonics to a Stetsom, for a price

An amp..should be an amp. There should be no processing or any associated stuff. Whatever you put in it..is what you should get out only bigger. Hell a lot of the Korean/Chinese amps don't even filter out the switching frequency operation of the output stage...that crap goes straight into the sub as well and inductively heats the tinsel leads up. And it is not just a 'straight' DC current, it is still oscillating...in the sense of hooking a battery up to the sub. Otherwise the sub would just move out or in and stay there to burn.

Scott and I have spent a LOT of time testing this with the pro sound amps in the shop, using our tone generator...the sub gets straight pissed...and it is because of clipping and the time value that everybody keeps forgetting about...that induces heat.

It's like holding a hyndai to the floor and bouncing it off the rev limiter, then yanking it in reverse...then back to forwards. The only time it is off the rev limiter is when it is bogging down attempting to move.

[Impious 1,476]

That clipped/squared wave at it's peak is direct current.

No, it's not.

Nick: Have you managed to determine a higher (quicker?) rate of failure for a clipped signal operating at equivalent average power levels as a non-clipped signal? Obviously a heavily clipped signal of the same RMS voltage as a non-clipped signal is going to cause a driver to fail sooner (if you breach the thermal or mechanical thresholds) as the clipped signal will deliver significantly more power over time. But I've not yet seen a test that determined a quicker failure rate for a clipped signal vs a non-clipped signal at the same average power level.....and I've never personally had enough drivers on hand to intentionally blow stuff up just for shits and giggles

[nartc 4]

Well guys, the way I see it: "If you fed a pound of $h!t to an elephant, don't expect a pound of peanuts on the other end."

[NDMstang65 403]

That clipped/squared wave at it's peak is direct current.

No, it's not.

Nick: Have you managed to determine a higher (quicker?) rate of failure for a clipped signal operating at equivalent average power levels as a non-clipped signal? Obviously a heavily clipped signal of the same RMS voltage as a non-clipped signal is going to cause a driver to fail sooner (if you breach the thermal or mechanical thresholds) as the clipped signal will deliver significantly more power over time. But I've not yet seen a test that determined a quicker failure rate for a clipped signal vs a non-clipped signal at the same average power level.....and I've never personally had enough drivers on hand to intentionally blow stuff up just for shits and giggles

Yep...which is the only reason why I'm debating it.

Same 4kw crown amp in the shop...sine wave, very cool sub is not pissed. Flip the signal generator over to square wave form...not so cool.

The time value of the 'flat' part of the wave at the two extremes literally makes the coil sit there..and do nothing, it is not in motion. It's just hanging out burning, like bouncing the Kia off of the rev limiter and dropping the tranny in reverse.

[onebadmonte 235]

That clipped/squared wave at it's peak is direct current.

No, it's not.

Thanks for the clarification, and for quoting me out of context. I guess me saying, "I've visualize it as connecting a battery directly to the speaker." wasn't obvious enough that it was my way of visualizing what is happening with a clipped signal. No biggie, just thought I'd clarify a bit as well.

[95Honda 486]

You just can't make a comparison with a function generator like that. The output of a function generator is regulated by Pk-Pk voltage, not power. So when you change the output to a square wave you have doubled the power.... Unless you normalize the power, which you can't do without additional test equipment, it is not a comparison.

[NDMstang65 403]

Still going to disagree..

You've doubled if not more the time per division of the wave form...hence a ton more heat.

It can not double the output power if it is already running at maximum output to begin with.

If all the amp will do is 200 volts, and 20 amps..that is all it will do. Even if you do normalize power at say 100 volts of output without "clipping" and then drive it with a square wave the sub still gets PISSED...which realistically would be less power on the coil that is driven with the square wave form on the per watt basis because impedance is much higher (voltage constant, current lower because of impedance rise due to more heat being induced)..if you normalize to 100 volts of output on square vs. sine wave. The "wattage" by normalizing power definition is no different, all the amp is making at that point is 100 volts, lower current with the square wave if anything, and the square wave form induces a shit ton more heat?

It is because it is going to the high point of the wave, stopping..burning. Immediately reversing and doing the exact same thing. It is hell on soft parts..and it burns the coils up...because it induces a TON more heat. Even using a fluke meter to test heat after driving the sub for 10 minutes..there is a very significant difference in heat in the coil with the square wave form.

[95Honda 486]

When you normalize the power, the square wave voltage is drastically lower, hence almost unchanged heat build up between the different waveforms when you do this.

We'll never agree on this, but that is OK.

I think you are about the only guy on here I will "disagree" with and still have respect for. Just about everyone else is full of shit on the subject....

Edited February 6, 2011 by 95Honda

[NDMstang65 403]

Definitely

Known you waaaaaaaaaaaaaaaaaaay too long.

We've said this a few times over the years