Leaderboard

Im sorry, I simply dont have time to read everything and make a point by point post... but when we tested amps and waveforms it was done with amps that were capable of making full voltage into both a square or a sine wave. At that, it is what I feel a real world clipping situation is. While it is pretty damn close to impossible to get a perfect square wave (and even more so into a reactive load, ie a speaker) we could tweak and get it fairly close. Points are, that most amps are capable of producing a pretty dang "square" square wave and that you can, within a percent or two, approximate Vrail as Vrms for a sqaure wave. While Vrms for a sine is .707Vrail. This equates to a situation where 40% more power is applied to the speaker in a MASSIVELY clipped scenario. But, we took it several steps further to use a laser based measurement system , an accelerometer, and two different thermal measurements (thermocouple as well as infrared) to measure things. At that we found the obvious, things heat up more, and often significantly more. This is due (based off of measurements of heat and excursion) the increased power and reduced excursion (for like power in a square vs sine wave the square wave has less excursion.... and at higher power and excursion levels where our cooling system comes in to play, was even more drastic). Now, the interesting side of things is even when normalized at higher power levels, we found that the square wave does induce more heat. Watts is Watts, so the reduced excursion simply means that our cooling system does work. Of note, but not particular to what has been discussed is the force being applied to the speaker in a square wave vs sine wave. A square wave is significantly more brutal (an order of magnitude more) on things mechanically. That is not fun for a speaker. Not too mention that getting smacked like that can lead to a already thermally stressed coil to come undone in a situation that similar power from a sine wave would hold together long enough to cool back down (less force/stress and higher excursion/cooling). All in all it doesnt equate to anything beneficial. Sounds like poop and is rough on speakers (and Im sure amps, but not as much my concern). Keep it clean and things stay happier. Thanks, Scott

If you have a signal that's 50V peak, run a sine wave and then a square wave at that same peak voltage into a 1ohm load you'll have average power of (50*.707)^2/1 = 1250w with the sine wave but 50^2/1 = 2500w with the square wave. Both signals will be within the rail voltage of the amplifier. The peak voltage of the signal hasn't changed, but the average power of the signal has increased significantly with the square wave. I guess my point is.....even if you take the same amplifier and run the same peak signal voltage for a sine wave and square wave through it.....the square wave will have significantly more average power than the sine wave even though the peak voltage of the signal hasn't changed (and hence both signals are within the rails of the amp). That 1000w amplifier is a 1000w amplifier with a sine wave, not a square wave. Average power will increase with the square wave, which leads to the build up of heat. Granted you may hit current or power supply limitations which will not allow the amplifier to output a full 2500w continuously.....but you'll be at the limits of the amplifier, which will result in an increase in average power with a square wave compared to a sine wave with the same amplifier, same peak voltage, within the rail voltages of the amplifier. If you are going to do a normalized average power comparison, which is what we are trying to compare, you have to reduce the peak voltage of the square wave so that both the sine wave and square wave have the same RMS voltage, which would give both signals equivalent average power. So a 50V peak sine wave would have an RMS voltage of 35.35V. The square wave would need to be reduced to a level of 35.35V for an equal average power comparison. So a square wave wouldn't hit the peak 50V and stay there, because it would peak at 35.35V. Only the sine wave would peak at 50V. This is what Sean, 95Honda and myself are arguing. With the same average power (i.e. the same RMS voltage, not peak voltage), there won't be a significant difference in heat and/or failure time within the driver. We can't just talk in terms of voltage alone, we have to differentiate between peak and RMS signal voltage, because that dramatically affects the average power of the signal. And you aren't going to make this comparison by only flipping the signal generator between sine and square wave, as the peak and RMS voltages of the signal would need to be adjusted to properly compare average power. I was thinking about something else on my morning drive......the square wave assumes essentially an instantaneous change in voltage level. If the signal is 5V peak to peak, the signal has a 10V swing in level with virtually zero change along the y-axis of time. Loudspeakers have inductance and energy storage......I would imagine there has to be some sort of "lag" present in the driver's ability to respond to an instantaneous change in voltage like that. The driver isn't going to be able to respond instantaneously and go from a position of +5V to -5V in almost literally no time. That's almost exactly what inductance describes...the ability of the driver to respond to a change in voltage. So I wonder how much "rounding" of the square wave there is in the actual response of the loudspeaker to the signal, as this would affect (reduce) the amount of time the driver was actually at the plateau of square wave, which would reduce the amount of heat build up you are suggesting occurs. By the time the speaker finally gets up there to the plateau of the square wave, the signal is turning around heading back down in the other direction, so the speaker turns around and follows it back down (obviously overly simplified). I wonder if it would almost "track" the same path as a sine wave due to the inductance induced lag. You're the speaker engineer Nick What do you think?

So, most of the parts are in. There's some fabricating that still needs to be figured out, but what the heck. Let's get the show started. Here is a pic of the ride: 2004 Suburban Work Truck Edition. It's white and has a rubber mat instead of carpeting on the floor. The interior, vinyl. 5.3 V8 and it's 4WD. The main source is a Alpine IVA-NAV-1 with a pair of Concept headrest monitors for the rear passengers. No pics yet Here is the front stage: Precision Power 355cs components in q-logic kicks, but wait there's more. o_o Can you guess what these are? One more pic.

welcome from the ne side

Of course it will be as it is MORE average power. Yes there is, power kills speakers. Or more correctly stated, there are two ways to kill a driver with a signal: 1) Overexcursion - cause by too much instantaneous power 2) A thermal death - caused by too much average power When describing a signal that is detrimental to the driver it has to be for one of the two reasons. And the only way heat can be increased is to increase the average power.

Go take a 120 volt lightbulb..put it on a sine wave Put a 120 volt light bulb now on a square wave. Tell me if the square wave one is not brighter. Rail voltage on an amplifier does not necessarily scale back...and it is not normalized. There is absolutely no point in normalizing things.

No. Basically: Square wave = more power at the same voltage. Turn down the voltage so it has the same power as the sine wave and the heating of the coil will be the same. Brad's lag comment actually says the contrary to what you think you understood that being the speaker cannot follow the path directly but lags and rolls that it will then come closer to following the sine wave and it would then make less heat not more. Either way, again motion and everything else is confusing this. It is really very simple. Average power through a wire creates heating. Same average power = same heating. There is nothing else to discuss on the heating side. If the topic switched to cooling and some other response because of waveform shape fine, but in the realm of heating via the Physics of power there is no difference in waveforms of the same average power. I will add that anyone that discusses instantaneous power as a heat source doesn't understand basic Physics as ignoring the time in the equation is not possible. Sorry that I am not as eloquent in my descriptions as Brad is, but hopefully my points have been clear. Don't stop asking questions or clarifying though, we don't always realize that you all don't follow

It takes power to make power.

it's for the bass silly

ip man ip man 2 inception martyrs (fucked up movie) scott pilgram vs the world the experiment the good, the bad, the weird the social network unstoppable good show to watch is spartacus

I recently download "I spit on your grave" and it was a pleasure to watch for sure. Here is a list of movies worth your time: Wild Target Sexy.Beast (2000) Danny.The.Dog (2005) Touching.The.Void (2003) - amazing Alpha Dog Escape.from.Alcatraz.1979 A.Perfect.Getaway.2009 Interview With The Vampire (1994) The.Time.Travelers.Wife.2009. Lock.Stock.and.Two.Smoking.Barrels (1998) Heat.(1995) - idk why I even put it in this list. Everyone should have watched it by now! Rain.Man 1998 Derailed L.A.Confidential how.to.lose.a.guy.in.10.days.2003 Gran Torino (2008) 16.Blocks.2007 The.Curious.Case.of.Benjamin.Button Sorry for the copypasta, it's from my list I got on a .txt

Thinking more.. We are not talking about taking a potential 1000 watt amp and making it run at 100 watts sine wave and then square waving it and getting 400 watts...that is a no brainer why you would have more heat. It is more power. We're talking about a 1000 watt amp, putting out maximum power with a sine wave at 1000 watts...it is then driven with a square wave, more heat is present than with a sine wave with the same 1000 watts. It can only make 1000 watts..that's all it can do. 100 volts and 10 amps for sake of the discussion...square wave..sine wave..pink noise..white noise..what have you. 1000 watts. But we really can't talk about watts at this point (because of the rms value here), what you need to look at is voltage. The rails are capable of doing 100 volts peak to peak..that is what it is capable of doing, that is what the square wave does. We are talking about a peaked out rail here...+/- 50 volts the sine wave just touches it. Your square wave hits it 100% of that energy for that period of time. Why is the coil 130 degrees hotter with the square wave form? If..'clipping' does not blow speakers or burn parts up. It has to be the amount of time that the speaker is 'on' 100% at the extreme north and south end where it literally sits there, does not move, and burns. This is not even looking into the MASSIVE acceleration factors and forces going on here either.. Edit: At the two extreme points the coil is 'stopped' or 'dead' and doing nothing but taking the grunt of the amp for the time value of the operating frequency of the output transistors...it's not doing anything (Back to the rev limiter analogy here) It is just like pushing the clutch in and holding the gas pedal to the floor bouncing the engine off of the rev limiter and jerking the gear shift into reverse. Still holding the accelerator to the floor and slamming it back in first..the time that the speaker is stopped is the period of time in which it takes you to physically switch the gear from reverse to forwards without using the clutch....which shanks gears in transmissions, snaps spiders in subs.. Which is due to acceleration factor and more energy per time division..which needs to be tested by an accelerometer..which i'll do when I have time. There is no clutch, there is no braking or slow down. You are 100% forward, and instantly stopping and 100% rearword...and burning in-between. Hope this helps.

I love how some idiot thumbed my comment down when I politely welcomed the sir to this forum. Dumbass. Your head:

Don't sweat it! Thanks for the movies Now I can go home and not be bored 8D

plent audio is probaly better quality

any 1 use these amps and which one puts out more power http://www.sonicelectronix.com/item_25297_Planet-Audio-BB1400.1.html

Audioque 1200.1?

I'm looking for movies that are worth the time of getting to watch, darmas, comedies, horror movies, anything you guys like! I hope this thread can be someone everyone can look at if they're in need of a movie to watch. If you can, state the name, and the year it was produced, thanks!

Thank you Phi I've watched Ip Man 1 & 2, crazy ass movies Inception is ridiculously awesome Unstoppable pretty damn cool man more movies!

Welcome! Where in Houston are you from?