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i just got 2 10in 600w subs today. i hooked them up without an amp because i dont have the money to get one right now...but i was wondering what amp (considering watts and my budget (not much)). how do you hook up an amp..maybe some pics or detailed instructions would help thanks..
 

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I'm not sure, but I think you can damage a Sub by underpowering it. That's why there is a RMS rating to them. IMHO, I would hold off hooking them up, until you hav an amp that can put out the ower they need. With my amp, I ran RCA's and a control wire from the HU under the passenger side doors into the trunk; and ran the power line from the battery through the firewall indies the driver's side fender, under the drivers side doors, and into the trunk. For the ground, you want less than 18" of ground wire, so I cleaned the paint off of a small section of the rear deck bulkhead, and tapped a screw in there, giving me only about 12" of ground wire.
 

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you cant do any damamge to a speaker by underpowering it, thats kind of like saying that you can ruin your car by not flooring it. the RMS rating is there to tell you how much power the subs can handle "continuously". they are usually rated for x amount of watts over a 4 hour time span.

as for choosing amps, you might wanna search ebay, you can find some great deals on there. i would strongly advise you towards an MTX amp, they are cheap, and MTX amps actually put out the power they are rated at. you also might look at a JBL amp, but if you go that route then buy a bigger amp than you need and keep the gains turned down low. the JBL amps do very bad things when they start clipping, and they can blow your woofer.

also, make sure to check out the RMS rating on your subs, you dont need a 1200 watt amp as im sure the 600 watt rating is "peak".
 

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Originally posted by hoss@Jan 1 2004, 07:11 PM
you cant do any damamge to a speaker by underpowering it, thats kind of like saying that you can ruin your car by not flooring it. the RMS rating is there to tell you how much power the subs can handle "continuously". they are usually rated for x amount of watts over a 4 hour time span.

as for choosing amps, you might wanna search ebay, you can find some great deals on there. i would strongly advise you towards an MTX amp, they are cheap, and MTX amps actually put out the power they are rated at. you also might look at a JBL amp, but if you go that route then buy a bigger amp than you need and keep the gains turned down low. the JBL amps do very bad things when they start clipping, and they can blow your woofer.

also, make sure to check out the RMS rating on your subs, you dont need a 1200 watt amp as im sure the 600 watt rating is "peak".
Umm... yes you can damage a speaker by underpowering it. The reason why you can damage it from underpowering is because the amp powering it will be at it's MAX output which wouldnt be sufficient for the speaker and will cause the amp to put out a distorted signal. We all know how good distortion is for a speaker...
 

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I'm no expert, but I'm going to have to agree with Hoss on this one. It doesn't make sense that you can have "too less" power. The amp will only put out as much power as you tell it to, and getting a bad signal doesn't seem like it will blow a sub. If that were true, everytime I listen to a fuzzy radio station, I should need new subs.... it's the same thing.
 

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Originally posted by Xmann01+Jan 1 2004, 09:46 PM-->QUOTE (Xmann01 @ Jan 1 2004, 09:46 PM)
<!--QuoteBegin-hoss
@Jan 1 2004, 07:11 PM
you cant do any damamge to a speaker by underpowering it, thats kind of like saying that you can ruin your car by not flooring it.  the RMS rating is there to tell you how much power the subs can handle "continuously".  they are usually rated for x amount of watts over a 4 hour time span.

as for choosing amps, you might wanna search ebay, you can find some great deals on there.  i would strongly advise you towards an MTX amp, they are cheap, and MTX amps actually put out the power they are rated at.  you also might look at a JBL amp, but if you go that route then buy a bigger amp than you need and keep the gains turned down low.  the JBL amps do very bad things when they start clipping, and they can blow your woofer.

also, make sure to check out the RMS rating on your subs, you dont need a 1200 watt amp as im sure the 600 watt rating is "peak".
Umm... yes you can damage a speaker by underpowering it. The reason why you can damage it from underpowering is because the amp powering it will be at it's MAX output which wouldnt be sufficient for the speaker and will cause the amp to put out a distorted signal. We all know how good distortion is for a speaker... [/b]
Try again.

Distortion is a signal. The speaker blindly plays anything it's given, it doesn't matter what it is... Saying that distortion kills speakers, is like saying my speakers will blow if I play Micheal Bolton. Sure, my passengers will probably try to remove the speakers when I play this, but it will not hurt them.

Underpowering will not kill a speaker. Clipping is a fancy name for distortion, audible or inaudible. Clipping is caused by the attempt to exceed the equipments rated output by raising the input sensitivity to a much higher than acceptable level. Worst case scenario, your speakers will see a square wave instead of a sine wave... big deal.

UNDERPOWERING WILL NEVER KILL A SPEAKER.

If anyone has any more questions, feel free... I have been installing for 8 years, and have owned my own installation company for 4 years now. I am also a certified electronics professional. If anyone doubts what I say above, I will show you proof.
 

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O.K., now I know for a fact that clipping will destroy a sub; Iv'e done it more than once on my bass amp setup (bass guitar). As for underpowering, here's what Iv'e found

http://www.crutchfield.com/S-iVNKTv9fJ67/tech/kb148.html

Very interesting. The title of the article is "Did you know that underpowering a subwoofer can be more dangerous than overpowering it? Ken Nail has some good tips for getting the most out of your subwoofer."
 

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Originally posted by silvapain@Jan 1 2004, 10:27 PM
O.K., now I know for a fact that clipping will destroy a sub; Iv'e done it ore than once on my bass amp setup. As for underpowering, here's what Iv'e found

http://www.crutchfield.com/S-iVNKTv9fJ67/tech/kb148.html

Very interesting. The title of the article is "Did you know that underpowering a subwoofer can be more dangerous than overpowering it? Ken Nail has some good tips for getting the most out of your subwoofer."
No.
 

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What's even worse, is that people actually believe this trash. You cannot, and will not kill a speaker by underpowering it, ABSOLUTELY NOT.

Now, lets talk about clipping for a minute... As I said before, the speaker does not know the difference. I'll give you a worst case scenario... the severely clipped signal of a 100watt amplifier, to the 300 watt subwoofer he used in the scenario in the article.. would at full tilt, clipping and all MAYBE hit the equivilent of 200watts thermally. So that article is complete BS. Why wouldn't they tell you that????? They make more money selling the larger amps... so why WOULDNT THEY want to sell you something larger by making you feel the need...

If you don't believe me, you're misinformed and I'm sorry to hear that.
 

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Underpowering the sub CAN damage the voice coil. If you are careful, and don't push it too hard without significant amplification, you will be fine. However, if you try to run a sub off of a low-output amp (or the head unit) and you push it hard, it WILL eventually be destroyed.

Here's ONE scenario in which underpowering a sub will destroy it. A hard bass note hits and you have the volume cranked way up. The sub jumps forward, but without a strong magnetic field in the voice coil to control the excursion, the voice coil does not move in a straight line. It basically has some side to side play in it. eventually, this weakens the spider and allows the voice coil windings to contact the magnet. With enough abuse, the windings will eventually short out and blow the entire voice coil.

I have seen this with my own eyes. A technician at the stereo shop I used to go to had a customer come in with a warranty claim. The guy had bought a pair of subs a few months before, and he had been running them off of a small (50x2 RMS) Jensen amp. One of the subs blew out, and the guy came into the shop and said he wanted 2 brand new subs, free installation, etc. since, according to him it was the stereo shop's fault. After some arguments back and forth, the guy threatened to sue the shop, the sales rep who sold him the subs, etc. He left the subs and box there so that the shop tech could see what was wrong with the subs. They disassembled both subs and found vertical scratches on both voice coils where the coils had been rubbing on the magnets. One of them had worn through some of the windings (that was the sub that was "blown.")

Having a sealed box offers some protection, as it controls the excursion of the sub a little better than a ported box.
 

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Originally posted by jdaniels@Jan 1 2004, 10:45 PM
What's even worse, is that people actually believe this trash. You cannot, and will not kill a speaker by underpowering it, ABSOLUTELY NOT.

Now, lets talk about clipping for a minute... As I said before, the speaker does not know the difference. I'll give you a worst case scenario... the severely clipped signal of a 100watt amplifier, to the 300 watt subwoofer he used in the scenario in the article.. would at full tilt, clipping and all MAYBE hit the equivilent of 200watts thermally. So that article is complete BS. Why wouldn't they tell you that????? They make more money selling the larger amps... so why WOULDNT THEY want to sell you something larger by making you feel the need...

If you don't believe me, you're misinformed and I'm sorry to hear that.


Sorry, but you need to do some research on this issue. I have had MANY serious systems in my vehicles over the years. I have read MANY books and magazine articles, and I have been to some competition events. I have spoken at length with many car stereo installers, and even industry professionals who manufacture speakers.

The truth is, you won't blow the sub if you keep the volume where it should be. If you want to push the sub hard, you better have some decent wattage to do it, or you are in serious trouble.
 

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Here. This is a guy who REALLY knows what he is talking about. It seems that underpowering isn't the issue, clipping of the signal is.....

Hi Randawg,
My name is Dan Wiggins. I'm the CEO and partner of Adire Audio. We're a high-end audio company located in Seattle, WA and have been in the audio business for 7 years. We started in advanced acoustics research and consulting, and over the last 4 years we've branched out into retail products as well. One of our many technologies that we've developed and license is in our Brahma woofers, the XBL2 motor, which set a world record in terms of linear excursion at 27.32mm one way.

My design partner is Dr. David Hyre. He earned his undergrad degree in physics, and his PhD in nuclear magnetoresonance spectroscopy, and has spent several years in advanced biochemistry where he worked on isolating and reversing the spin on individual electrons. This required use of extremely strong and precise magnetic fields, with gradients measured in the range of a few Teslas per millimeter.

Anyway, I see you have a few questions about our paper. Perhaps I can explain. I don't know what your background is (my is a BSEE, and 13 years of advanced SONAR system design prior to the last 7 in the audio acoustic range), so I'll try to keep things fairly simple. But if you need more thorough explanations, please let me know and we can flesh things out further.

- Underpowering destroys drivers. I believe Tracy (hi Tracy! Missed you at CES; I'm still here in LV, enjoying a bit of sun...) summed it up correctly: underpowering isn't a problem. Overpowering or overexcursion are.

A driver's excursion is a function of the current flowing in the motor AND the stiffness of the box behind it. A larger box means less current flow required (less power, since power is current squared times impedance) to reach a given excursion level. In fact, you can push just about any driver to full linear excursion with a couple hundred watts, depending upon the box and signal used.

Overexcursion is bad for a sub in two ways. The first is physical damage. You can snap tinsel leads, bottom the voice coil, wedge the voice coil on the top plate (if you walk it out the front of the gap; a common occurance with flux modulation effects), tear spiders, etc.

The second problem with overexcursion is reduced cooling. Over 90% of the heat dissipation in a driver comes from air movement in the motor, not conduction through the pole, top plate, etc. When you linearly scale air motion with power - like when a driver is still within it's linear range of motion - you're generally OK. But when you reach the suspension limits and keep increasing power, you get into trouble. It's like restricting the cooling air to the motor; akin to placing a restrictor plate in front of the radiator in your car. As you run with more and more motor output, heat builds up. And if you restrict the cooling - or hold it's level constant - you can't remove the heat as effectively, meaning a meltdown in imminent.

As far as damaging from underpowering, it really can't happen. It can happen if you CLIP the amp, but that's not from the amp being underpowered; it's from the amp generating even more power. Please see the eatel.net site for a VERY good description of the way the power envelope increases from a clipped signal. It's not the fact the amp is underpowered; it's the fact that you are increasing the power to the speakers, usually beyond it's rating.

- Mass affects transient response. Please investigate the works of Tom Danley, Dr. Floyd Toole, Dr. Wolfgang Klippel, Thiele, Small, Benson, Bullock, Geddes, and several others. They all make the complete conclusion that inductance is the primary limiter of frequency response, NOT mass. Mass can have a very small second-order effect (due to the way mass shows up as an inductive reactance in the electromechanical model), but it is often two orders of magnitude below that of the voice coil. Voice coil inductance is the limiter.

As far as the ability to infinitely slew current, you are of course correct about the speed of light. However, I guess I was not clear enough about the whole statement: IF you could slew the current at an infinite rate, then you would have infinite transient response. obviously you can't do that (I assume a certain level of education in the reader), but the point is still valid; what limits transient response is how fast you can change the current.

Transient response is a 3rd order function. It is the rate of change of acceleration; it is NOT acceleration itself. With the equation of BLi=ma, BL and m are both constants (when doing the time-based derivative). They will scale your results, but are not changing things in a time-dependent manner. That leaves i ~= (proportional) to a, so that to change a one must change i. That is, changes in acceleration - transient response - are proportional to changes in current.

What limits current flow in a time-dependent manner? Inductance. This is where the limit comes from. You can only slew the current through the inductance of the voice coil so fast; the lower the inductance, the faster you can change, and vice versa. In fact, if the current never changed, the acceleration would never change, and you would have zero transient response!

Mass and BL are scalars in the response system of the driver; they will change how much current is required to change the transient response of the driver. increasing mass will definitely mean you need more current to reach a given acceleration; however, it will not place an upper limit on how fast you can accelerate.

Likewise, BL is a scalar of transient response. The higher the BL, the faster you can accelerate for a given current. If you increase BL, you need less current to reach a given acceleration. But BL does not limit transient response itself.

For those who stop by our shop, I often do a demo to disabuse them of the notion that moving mass means slow response. I start with a Brahma 10, and run it through some healthy, 2" peak to peak excursion down around 15 Hz. Then I turn the power down, and start increasing the frequency. 50 Hz, 100 Hz, 200 Hz, 500 Hz, etc. until we reach 10 kHz, 11 kHz, and finally 13 kHz where it starts rolling off strongly. And this is for a driver with a moving mass of 160 grams.

As far as "audiophiles" using light cones, it's more a belief in the audio myth than for real reasons. I do work in the high-end market, and having just spent 4 days at the high end section of CES, I can assure you that voodoo and snake oil and lack of understanding about the fundamentals of physics are quite prevalent. Simply because of driver sounds a certain way does not mean that any theory applied to it is correct; often the description of the sound is correct but the wrong reasoning is applied, and thus the fundamental understanding of the technology is flawed. That is one reason why the audio field advances at a much slower rate than other high technology fields - many working in audio simply lack the training and knowledge to make correct correlations.

Thanks,

Dan Wiggins
Adire Audio


It'a made me change my mind.
 

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Originally posted by SixFoFalcon@Jan 1 2004, 10:51 PM
Underpowering the sub CAN damage the voice coil. If you are careful, and don't push it too hard without significant amplification, you will be fine. However, if you try to run a sub off of a low-output amp (or the head unit) and you push it hard, it WILL eventually be destroyed.

Here's ONE scenario in which underpowering a sub will destroy it. A hard bass note hits and you have the volume cranked way up. The sub jumps forward, but without a strong magnetic field in the voice coil to control the excursion, the voice coil does not move in a straight line. It basically has some side to side play in it. eventually, this weakens the spider and allows the voice coil windings to contact the magnet. With enough abuse, the windings will eventually short out and blow the entire voice coil.

I have seen this with my own eyes. A technician at the stereo shop I used to go to had a customer come in with a warranty claim. The guy had bought a pair of subs a few months before, and he had been running them off of a small (50x2 RMS) Jensen amp. One of the subs blew out, and the guy came into the shop and said he wanted 2 brand new subs, free installation, etc. since, according to him it was the stereo shop's fault. After some arguments back and forth, the guy threatened to sue the shop, the sales rep who sold him the subs, etc. He left the subs and box there so that the shop tech could see what was wrong with the subs. They disassembled both subs and found vertical scratches on both voice coils where the coils had been rubbing on the magnets. One of them had worn through some of the windings (that was the sub that was "blown.")

Having a sealed box offers some protection, as it controls the excursion of the sub a little better than a ported box.
Thats complete BS. If you guys don't beleive me, go do some REAL research... The spiders job IS to move with the cone, thats what it's there for. It's a VITAL part of the speaker.

Do you think I'm some rookie?

I've had this discussion with several people before, and I'd hate to tell you.. you guys have absolutely no clue on this.

I'm sorry, you are all wrong. Except hoss, he's on the right track although JBL amps don't clip any worse than the next guys
.


DO I HAVE TO BRING RICHARD CLARK IN HERE?
 

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Lol, Dan Wiggins was one of the ones who had to come into the last conversation I got into on this... after him, and then Richard Clark came... the guy STILL insisted they were wrong.

Did you guys REALLY think I was pulling this from my... well.. lets just say Left Field?
 

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Originally posted by SixFoFalcon+Jan 1 2004, 10:57 PM-->QUOTE (SixFoFalcon @ Jan 1 2004, 10:57 PM)
<!--QuoteBegin-jdaniels
@Jan 1 2004, 10:45 PM
What's even worse, is that people actually believe this trash. You cannot, and will not kill a speaker by underpowering it, ABSOLUTELY NOT.

Now, lets talk about clipping for a minute... As I said before, the speaker does not know the difference. I'll give you a worst case scenario... the severely clipped signal of a 100watt amplifier, to the 300 watt subwoofer he used in the scenario in the article.. would at full tilt, clipping and all MAYBE hit the equivilent of 200watts thermally. So that article is complete BS. Why wouldn't they tell you that????? They make more money selling the larger amps... so why WOULDNT THEY want to sell you something larger by making you feel the need...

If you don't believe me, you're misinformed and I'm sorry to hear that.


Sorry, but you need to do some research on this issue. I have had MANY serious systems in my vehicles over the years. I have read MANY books and magazine articles, and I have been to some competition events. I have spoken at length with many car stereo installers, and even industry professionals who manufacture speakers.

The truth is, you won't blow the sub if you keep the volume where it should be. If you want to push the sub hard, you better have some decent wattage to do it, or you are in serious trouble. [/b]
The BS flag just got eaten by moths.

I don't care how many "Serious Sound Systems" you've had. I've been installing for years. I have plenty of trophies under my belt, mostly for SPL. I beat the hell out of my equipment on a daily basis, I know what I'm doing too.

I don't hold it against you guys for being misinformed, it's been drilled into peoples heads for years now... these theorys just don't hold up. Some manufacturers use these theorys as a way of out warrantys as well.

Just some food for thought.
 

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I'm not saying you don't know anything about subs. And I know for a fact that Hoss knows more about car audio than just about anyone here. I'm just saying that it IS possible to damage your subs by running them off of a POS underpowered amp, or worse, your head unit. With a really good quality sub, and a good quality box, you have a lot more freedom to crank them without damage. But with some subs, the voicecoil is practically rubbing against the magnet to begin with. If you start trying to pound it with a puny amp, the amp lacks the power to return the sub to its original position. Instead, the spider and surround to most of the work. In time they won't be pulling it straight back, and the voicecoil will contact the magnet. By this point you are running on borrowed time, and it is only a matter of time before the sub is shot.

The solution is, if you must use a small amp or your head unit, don't crank the subs to the point where you hear distortion. It is not the distortion that will kill the sub, but it shows that you don't have the power to control the voicecoil the way it was intended.
 

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Originally posted by silvapain@Jan 1 2004, 11:06 PM
I just want to apoligize to everyone about starting this crap. Man, I got to keep my mouth shut more often.
Nothing wrong with opening your mouth... Atleast now everyone knows the truth, right? If you didn't say anything you wouldn't know either.


Just want to let you guys know, that my posts are not meant to slander anyone, or put anyone down... just to let the truth be known...


We're all supposed to be friends here, anyways... right?

On that note, I will leave you with several Dancing Banana's
and a chili pepper
 

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Originally posted by SixFoFalcon@Jan 1 2004, 11:12 PM
I'm not saying you don't know anything about subs. And I know for a fact that Hoss knows more about car audio than just about anyone here. I'm just saying that it IS possible to damage your subs by running them off of a POS underpowered amp, or worse, your head unit. With a really good quality sub, and a good quality box, you have a lot more freedom to crank them without damage. But with some subs, the voicecoil is practically rubbing against the magnet to begin with. If you start trying to pound it with a puny amp, the amp lacks the power to return the sub to its original position. Instead, the spider and surround to most of the work. In time they won't be pulling it straight back, and the voicecoil will contact the magnet. By this point you are running on borrowed time, and it is only a matter of time before the sub is shot.

The solution is, if you must use a small amp or your head unit, don't crank the subs to the point where you hear distortion. It is not the distortion that will kill the sub, but it shows that you don't have the power to control the voicecoil the way it was intended.
That's not true though, the spider and surround do the work to return the speaker to center position anyways. Using less power on them will just make them quieter. Again, even though clipping an amp isn't the best thing in the world, it still doesn't mean it will ruin the speaker. Like I said, clipping a 100watt amp will be like pushing the speaker with 200watts of clean power, just not AS loud. It won't hurt the sub, as long as it's within a decent range. A 100watt amp used properly, on any speaker that can handle 100w or greater will be fine. If you have 200watt sub, and a 100watt amp.. you're fine too... even fully CLIPPED.

If you want more information on subwoofers, or speakers in general... you can ask my buddy Dave at Resonant Engineering who builds the subwoofers that I use... I'm sure he'll tell you the truth... Or Ben at Elemental Designs.... or maybe Dan at Adire...
 
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