Experts especialy please read.

 

Bronze Member
Username: Super_mario

Post Number: 91
Registered: Mar-06
"I can drive speakers with a 100% clipped square wave
signal all day long with no problems as long as the
absolute thermal and mechanical limits of the speaker
are not exceeded."

Please read this carefully and give you opinion on this statement. If you have good facts please state them.it seems as thought it contridicts itself by saying it will clipp a sub all day long but will never exceed its thermal/mechanical limits??? Thank You
 

Gold Member
Username: James1115

Ct

Post Number: 6086
Registered: Dec-04
that is completely a false statement. It doesnt matter at what power the sub is clipped at it will destroy it. Obviously the more power the faster it will be destroyed but it will eventually blow a 1000 watt RMS sub with a 100 watt clipped signal.
 

Gold Member
Username: Basshead86

Google is your Friend, FL

Post Number: 4432
Registered: Aug-05
true. you can drive a speaker with a clipped wave. you better make sure however that is doesn't exceed the VC's DC current capabilites.

and WTF would oyu want to do that???

square wave = Distortion.
Upload
 

Gold Member
Username: James1115

Ct

Post Number: 6088
Registered: Dec-04
a VC's dc capabilities isnt very high
 

Gold Member
Username: Basshead86

Google is your Friend, FL

Post Number: 4433
Registered: Aug-05
exactly^^^^:-)
 

Gold Member
Username: Drivingreckless

Near tampa, Florida United state...

Post Number: 1532
Registered: Apr-06
exactly^^^^:-)
 

Silver Member
Username: Wingmanalive

Greensburgh, PA US

Post Number: 145
Registered: Jun-06
Upload
 

Gold Member
Username: Basshead86

Google is your Friend, FL

Post Number: 4437
Registered: Aug-05
lmao!!!

Paul is the best. lol
 

Gold Member
Username: Basshead86

Google is your Friend, FL

Post Number: 4438
Registered: Aug-05
are you arguing with someone on another forum and they said that?????

i would like to meet the person who would need to do that to a speaker. what does that prove?? lol
 

Silver Member
Username: Alexv305

Tavernier, FL USA

Post Number: 339
Registered: Oct-05
^^agreed..
 

Silver Member
Username: Troy81

Tavernier, Fl Us

Post Number: 931
Registered: Mar-06
well, ive clipped my memphiss and they never blew, i had my 1000d turned all the way up and it was putting like 1300 watts out and im damn sure it wasnt clean
id say it was a square wave but maybe it wasnt also i was only giving it 11.4 volts
 

Gold Member
Username: Illuminator

USA

Post Number: 4030
Registered: Apr-05
I completely agree with the statement in the original post and Rockford Fosgate does too:


quote:

The "Dirty" Truth About Distortion
Contrary to popular belief, distortion does not cause speaker damage. Distortion is merely the audible detection of signal "clipping". Clipping is when an audio component can no longer provide enough power supply voltage to "cleanly" amplify the audio signal. Clipping can occur at any point in the signal chain (souce unit, signal processor, amplifier, etc.) The popular belief is that if an amplifier "clips" it will send D.C. current to the speaker's voice coil and "burn" it. THIS IS NOT TRUE. It would surprise you to realize nearly every car audio system's amplifier "clips" when listening to music at moderate -to- loud levels. Electrically overpowering a speaker is caused by continually playing the audio system loud, resulting in applying more power to the speaker than it's "rated" specifications. This is what causes speaker voice coils to "burn".




Source:http://www.rockfordfosgate.com/scripts/rightnow.cfg/php.exe/enduser/std_adp.php? p_sid=NWNql5fi&p_lva=&p_faqid=63&p_created=965346111&p_sp=cF9ncmlkc29ydD0mcF9yb3 dfY250PTIxNiZwX3BhZ2U9MQ**&p_li=
 

Gold Member
Username: Basshead86

Google is your Friend, FL

Post Number: 4439
Registered: Aug-05
that is B.S.


DC doesn't allow the VC to move properly and it burns up b/c there is no break in current

or so i am told.
 

Silver Member
Username: Wingmanalive

Greensburgh, PA US

Post Number: 148
Registered: Jun-06
Upload
 

Silver Member
Username: Troy81

Tavernier, Fl Us

Post Number: 932
Registered: Mar-06
well i couold play my memphiss all day clipped at full blast and they were fine, they stunk like poo but they never blew for like 2 months everday almost all day, so i think they may have had something wierd about em cuz ive tried to blow em and couldnt, and i was over powering them by 350"dirty"rms
 

Silver Member
Username: Wingmanalive

Greensburgh, PA US

Post Number: 149
Registered: Jun-06
Was that out of line??^^^^^^^
 

Gold Member
Username: Basshead86

Google is your Friend, FL

Post Number: 4440
Registered: Aug-05
lmao^^^

DC current burns VC's.....TRUTH
DC current build up heat faster and it can't be effectively dissipated.....TRUTH
Clipped signals sound bad....TRUTH

not from overampifying it. lolol silly rabbit:-)
 

Gold Member
Username: Basshead86

Google is your Friend, FL

Post Number: 4441
Registered: Aug-05
if that was the case....then every DD on the market would be blown. from beinf overamplified.

try again RF. :-O
 

Silver Member
Username: Troy81

Tavernier, Fl Us

Post Number: 933
Registered: Mar-06
well, DC makes the voice coil go up and stay up for too long cuz it doesnt have the current passing the other way to bring it back.

AC is alternating like a sub should do, and DC is like one way, so if you give it straight DC it will go either up or down and stay there untill you switch the polarity, ac automaticall switches the polarity when it is told to switch it
 

Silver Member
Username: Alexv305

Tavernier, FL USA

Post Number: 340
Registered: Oct-05
Its sort of a weird discussion because its somewhat true, although I have not researched this. This is what i conclude...

The RMS rating of a driver is only the "electrical" capabilities of the driver. Mechanically, it may not be able to take that much power because the driver's cone begins to lose its balance and thus damage the coils due to improper excursion.. I have underpowered speakers and all it does is produce a undesirable sound and this is why most people say overpowering is better.

On my budget, I cant afford to drive a subwoofer with an amplifier within 10% of its power range. Such as pushing a 1000watts RMS sub with 100watts of pure distortion to conclude this theory..

Correct me if I am wrong..
 

Gold Member
Username: Basshead86

Google is your Friend, FL

Post Number: 4442
Registered: Aug-05
just so this doesn't turn into a flame war.

yes i agree. you can, but why bother????

and no DC current does blow subs. not just from giving it too much power.
 

Silver Member
Username: Alexv305

Tavernier, FL USA

Post Number: 342
Registered: Oct-05
I havent expirimented this but I would say DC current damages the sub. At a given frequency, lets say 40hz sine wave; when you test it for AC on a multimeter, the voltage is constantly changing even as the volume stays the same. AC is what causes the driver to move in and out. DC might just push the sub linear one way constantly and strain the sub due to improper cooling, as subs need excursion IN and OUT to allow air to run through the driver.
 

Silver Member
Username: Troy81

Tavernier, Fl Us

Post Number: 934
Registered: Mar-06
to add to alexs it also over excerts the sub bye constantly pushing it out and out and vnot pulling it back so its also mechanically over exurting it
 

Gold Member
Username: Illuminator

USA

Post Number: 4031
Registered: Apr-05
I've never been able to blow a speaker from underpowering it with clipped power. Seriously, has anyone?

Anyway, Muddy brought up the best point:

quote:

i would like to meet the person who would need to do that to a speaker. what does that prove?? lol




lol, exactly...who cares?
 

Gold Member
Username: Basshead86

Google is your Friend, FL

Post Number: 4445
Registered: Aug-05
thanks Jexx. lol:-)
 

Silver Member
Username: Troy81

Tavernier, Fl Us

Post Number: 935
Registered: Mar-06
wont have to spend as much on an amp if all this is true jexx
 

Silver Member
Username: Alexv305

Tavernier, FL USA

Post Number: 343
Registered: Oct-05
Future of pure SPL? ROFL..j/p
 

Silver Member
Username: Alexv305

Tavernier, FL USA

Post Number: 344
Registered: Oct-05
Troy..who would want a clipped signal anyways?
 

Silver Member
Username: Troy81

Tavernier, Fl Us

Post Number: 937
Registered: Mar-06
im thinkin imma do some research and figure it out cuz if you dont send a sub past its x max then it wont get to hot but if it goes past that due to DC current then it will definately heat up, and if this is true you could buy a cheaper amp that puts out lets say 600 dirty rms and push a 600 rms sub and be fine, it would just sound terrible, but like i say, imma do some research
 

Silver Member
Username: Troy81

Tavernier, Fl Us

Post Number: 938
Registered: Mar-06
alex... someone that wants pure spl, no SQ at all,
 

Silver Member
Username: Alexv305

Tavernier, FL USA

Post Number: 346
Registered: Oct-05
No Troy, this is where your wrong. For 600watts RMS and a ugly signal, your better off buying something around 300watts RMS of a quality build amp. Remember twice the power is only a 3dB gain. So actually 450-500 watts RMS would sound good coming from a quality amp.
 

Silver Member
Username: Troy81

Tavernier, Fl Us

Post Number: 939
Registered: Mar-06
i know but .3 db can win a DB comp and if you dirty up your speaker and get those Dbs you can win
 

Gold Member
Username: Basshead86

Google is your Friend, FL

Post Number: 4447
Registered: Aug-05

quote:

if you dont send a sub past its x max then it wont get to hot




what??

Xmax has nothing to do with thermal capabilites.

sending a sub past its Xmax is a mechanical limit. and oyu are more likely to tear the surroound or bust the VC.
 

Gold Member
Username: Illuminator

USA

Post Number: 4034
Registered: Apr-05
http://realmofexcursion.com/videos/RadioShack/8.1.wmv

That's the purest form of DC there is, and that speaker (as crappy as it is) doesn't blow! He has to put wall-socket AC on it to get it to fry.
 

Silver Member
Username: Alexv305

Tavernier, FL USA

Post Number: 347
Registered: Oct-05
Troy just STFU. DC is terrible for subs..And Jexx its only correct to a certain extent.
 

Silver Member
Username: Troy81

Tavernier, Fl Us

Post Number: 941
Registered: Mar-06
sorry, what i ment was if it STAYS past its x max it wont cool so it will get hot,
 

Gold Member
Username: James1115

Ct

Post Number: 6091
Registered: Dec-04
this should solve a few of the above questions. When a woofer is driven with a high powered amplifier to high levels, there will be a significant amount of current flowing through the voice coil. Since the voice coil has resistance, there is a voltage drop across the speaker's voice coil (which the amplifier appreciates greatly :-). This means that there may be a great amount of power being dissipated (in the form of heat) in the voice coil. When a speaker is driven with lots of clean power, the cone moves a great deal (in proportion to the output voltage from the amplifier). For speakers with vented pole pieces (or other types of venting), this movement forces a lot of air to flow in the magnetic gap (area where the voice coil rides). When the woofer moves out of the basket, the chamber that's under the dust cap and around the voice coil expands (increases in volume) which pulls cool air into the magnetic gap. When the woofer moves the other direction, the chamber size is reduced and the hot air is forced out of the vent in the pole piece. This air flow cools the voice coil. If a relatively low powered amplifier is driven into clipping (to a full square wave for a lot of people), a relatively large portion of the time, the voltage delivered to the voice coil no longer resembles a sine wave as it would with an unclipped signal. While the amplifier's output is clipped, the voice coil is not being motivated to move as far as it should for the power that's being delivered to it and therefore is likely not being cooled sufficiently (since the speaker is driven by a linear motor, the voltage applied to the voice coil determines how far the voice coil moves from its point of rest). At points a, b, d, e, f and h the voltage is changing causing the voice coil to move in the gap and therefore pull in fresh cool air. At points c and g, the voice coil may still be moving a little due to momentum but may not be moving enough to cool properly. Remember that during the clipped portion of the waveform current is still flowing through the voice coil. Since the displacement of the voice coil (and therefore the airflow around the voice coil) is no longer proportional to the heat being generated, the voice coil can overheat. This excess heat may cause the voice coil former to be physically distorted and/or melt the insulation off of the voice coil wire and/or cause the adhesives to fail (especially if the speaker is rated to handle no more than the power that the amp can produce cleanly). If your speakers are rated (honestly) to handle the maximum 'clean' power that your amplifier can produce, slight clipping isn't generally a problem. Severe clipping is more likely to cause a problem.
 

Silver Member
Username: Alexv305

Tavernier, FL USA

Post Number: 348
Registered: Oct-05
Troy agian STFU and you too JEXX cause look at the video carefully. DC is coming from those batteries and hes not keeping the leads on the battery for more than 1 second bursts. Then the wall socket has so much power it fries the coils easily... Also notice how the sub only goes one way when he hooks it up to the DC current (the battery).. So please go read some more about AC and DC...
 

Silver Member
Username: Troy81

Tavernier, Fl Us

Post Number: 942
Registered: Mar-06
and jexx those batterys are only like 200 watts tops, i forgot the equation and im too lazy right now but its somethin like 12^2 * somethin , but i forgot, but yeah its not that much and hes not holding it there for any length of time, its almost like AC current cuz its not holding it in one spot so sorry but that absolutely doesnt prove anything
 

Silver Member
Username: Alexv305

Tavernier, FL USA

Post Number: 350
Registered: Oct-05
Thank you James...Now anyways when you clip an amp to 100% say goodbye to it... :-)
 

Gold Member
Username: James1115

Ct

Post Number: 6092
Registered: Dec-04
EXACTLY!
 

Silver Member
Username: Wingmanalive

Greensburgh, PA US

Post Number: 151
Registered: Jun-06
Wow. I need a snack after all that....
 

Silver Member
Username: Alexv305

Tavernier, FL USA

Post Number: 351
Registered: Oct-05
Lol im with Paul. bbl ima go eat some dinner..
 

Silver Member
Username: Troy81

Tavernier, Fl Us

Post Number: 943
Registered: Mar-06
ok alex, ac current is just dc current switchin directions, so how does dc current definately hurt subs, its NOT definate and you just say STFU because you know you cant prove me wrong, im not sure it doesnt hurt subs, and i probably does due to heat but before heat becomes a problem im willing to bet as long as it isnt constantly drivin up and up or down and down it will not hurt anything
 

Silver Member
Username: Troy81

Tavernier, Fl Us

Post Number: 944
Registered: Mar-06
alex you know tony had my gain all the way up so you cant say it ruins the amp immediately, btw that was the installer so i could get my warranty but he hooked it up in a way worse manner then i wouldve, but unless memphis is truly that amazing which idk, i think clipping is a sound and heat issue
 

Silver Member
Username: Alexv305

Tavernier, FL USA

Post Number: 352
Registered: Oct-05
Troy your wrong again. If you have a low signal input to your amp then you would have to turn up the GAIN to get full power from the amp. Considering that you have a Sony headunit, this would prove my point.
 

Silver Member
Username: Alexv305

Tavernier, FL USA

Post Number: 353
Registered: Oct-05
Oh and one more thing. When a sub gets 30 volts AC current. The current goes from negative to positive, which creates sound. DC current will push the sub one way and forcing it to stay there witch would create little, no, or undesirable sound. So please keep reading.. You know your my boy no matter what, Im just trying to save you from looking like a complete idiot here on ecoustics.
 

Silver Member
Username: Troy81

Tavernier, Fl Us

Post Number: 946
Registered: Mar-06
but if you turn up the gain your clipping, you JUST said if you have 100% clipping say bye bye, which obviously its not 100% but it was clipping very bad and it didnt hurt anything, also i dont even have preouts on my sony its a line out converter so its like 1 volt preout so almost anyhting i put in my car is clipping, so idk where you think i was wrong cuz the higher you set your gain past where it has to be the more clipping you produce by making your amp try to make sound from nothing
 

Gold Member
Username: Illuminator

USA

Post Number: 4035
Registered: Apr-05

quote:

DC current will push the sub one way and forcing it to stay there witch would create little, no, or undesirable sound




Are you saying that will damage the speaker?
 

Silver Member
Username: Alexv305

Tavernier, FL USA

Post Number: 354
Registered: Oct-05
It will most likely damage the speaker because it will not allow the driver to ventilate. Come on Jexx, just read..
 

Gold Member
Username: Basshead86

Google is your Friend, FL

Post Number: 4449
Registered: Aug-05
a square wave still moves the cone both ways....just not effectively..


think of it like this


-------out
======stays(not moving so not cooling, and high current still flows through the VC)
________in
======stays(ditto)
-------out
======stays(ditto)
________in

blown VC
 

Silver Member
Username: Troy81

Tavernier, Fl Us

Post Number: 949
Registered: Mar-06
yes but by switching DC that would be changing th polarity hence making AC current
 

Silver Member
Username: Alexv305

Tavernier, FL USA

Post Number: 356
Registered: Oct-05
Exactly....Thank you Muddy...Thats why I said little or no sound...
 

Gold Member
Username: Basshead86

Google is your Friend, FL

Post Number: 4451
Registered: Aug-05
a square wave ITSELF will not blow a VC.....the heat buildup WILL.

distortion is just the audible aspect of the square wave. aka DC:-)
 

Gold Member
Username: Illuminator

USA

Post Number: 4036
Registered: Apr-05

quote:

It will most likely damage the speaker because it will not allow the driver to ventilate. Come on Jexx, just read..




I TRIED IT. Just now. I got a 50w Onkyo speaker and hooked it up to my 12v DC 30A power supply. I held the speaker in the down position for two FULL minutes. NOTHING happened! I hooked the speaker up to a stereo and it still sounds EXACTLY THE SAME. The speaker hardly even pulled 5A of power from the supply! DC CURRENT DOES NOT DAMAGE SPEAKERS.

I plan to repeat test this and hopefully get some video of it up soon!
 

Silver Member
Username: Troy81

Tavernier, Fl Us

Post Number: 951
Registered: Mar-06
"ac current is just dc current switchin directions"

dc current would only be able to switch directions bye switching polarity which is exactly what AC current is, and yes your my boy, im just tryin to keep you from looking like an idiot here on ecoustics
 

Gold Member
Username: Basshead86

Google is your Friend, FL

Post Number: 4452
Registered: Aug-05
i think the terms DC and clipped signal do not go hand in hand. you can have a clipped AC wave.

DC is when the sub only stays in one position. like a batt.
 

Silver Member
Username: Troy81

Tavernier, Fl Us

Post Number: 952
Registered: Mar-06
btw, i just did it 12 volts is only 36 watts
 

Silver Member
Username: Troy81

Tavernier, Fl Us

Post Number: 953
Registered: Mar-06
btw, i just did it 12 volts is only 36 watts

@ 4 ohms any more ohms the equation is 144/ohms
 

Silver Member
Username: Wingmanalive

Greensburgh, PA US

Post Number: 152
Registered: Jun-06
All this reading and drinking and now it's.......Upload
 

Silver Member
Username: Alexv305

Tavernier, FL USA

Post Number: 357
Registered: Oct-05
Jexx remember about resistance!! That driver isnt getting nearly the power it needs to allow the coils to heat up..Why dont you leave it on there for a good 4 or 5 hours and tell me what happends..lol
 

Gold Member
Username: Illuminator

USA

Post Number: 4038
Registered: Apr-05
I 'underpowered' a speaker by sending it a 'clipped' signal a.k.a. pure DC current and it was under its power limits...didn't blow.

On the other hand, if I would have exceeded its power handling capacity by feeding it more voltage @DC the speaker would have been electrically overpowered and surely would have blown.

Wanted to make that clear.
 

Silver Member
Username: Alexv305

Tavernier, FL USA

Post Number: 358
Registered: Oct-05
One word "RESISTANCE"!!
 

Gold Member
Username: Basshead86

Google is your Friend, FL

Post Number: 4453
Registered: Aug-05
correct...if the speaker is designed to handle 300wRMS.....it will not blow from 300wRMS DC....not right away.
 

Silver Member
Username: Alexv305

Tavernier, FL USA

Post Number: 359
Registered: Oct-05
Like I said Jexx, hold it there for a good few hours and then reconclude your expiriment..
 

Gold Member
Username: James1115

Ct

Post Number: 6094
Registered: Dec-04
go to www.bcae1.com and read up it's the voltage of the square signal that produces the excessive heat which causes the damage. A amp at full clip can produce double the power it is rated for. Therefor the voltage of the clipped signal is even higher. Lets say you have a 100 watt true power amp that same amp clipped at full could deliver upto 200 watts but the clipped square signal will produce moren then double the voltage of a 100 watt pure signal. Here is a formula.

Clean Signal Calculations:
P = E^2/R
P = 20^2/4 (4 ohm speaker)
P = 400/4
P = 100 watts RMS

Square Wave Signal Calculations:
P = E^2/R
P = 28.28^2/4 (the RMS voltage is 1.414 times the RMS voltage of the sine wave)
P = 800/4
P = 200 watts RMS

If your speakers are capable of handling significantly more than your amplifier can produce, driving them with a clipped signal will not likely hurt them.
If the speakers can handle 3 or 4 times the power that your amplifier can produce, there's virtually no way to damage your speakers (no matter how clipped the signal is).
If your speakers are rated for the same power handling as your amplifier is capable of producing cleanly, driving them with a clipped signal for extended periods of time may cause speaker damage and/or premature failure.
If your speakers are rated for the same power handling as your amplifier is capable of producing cleanly, driving them with a square wave signal for extended periods of time will likely cause speaker damage.
 

Gold Member
Username: James1115

Ct

Post Number: 6095
Registered: Dec-04
that should end it all
 

Gold Member
Username: Basshead86

Google is your Friend, FL

Post Number: 4454
Registered: Aug-05
you can kill a sub faster by overpowering it with AC .

than underpowering it with DC.


IS THAT WHAT YOU MEAN TO SAY JEXX??? lol
 

Silver Member
Username: Troy81

Tavernier, Fl Us

Post Number: 955
Registered: Mar-06
id like to add it will only damage it by heat
 

Silver Member
Username: Alexv305

Tavernier, FL USA

Post Number: 360
Registered: Oct-05
^^Exactly what I said but a more complex version..
 

Gold Member
Username: Basshead86

Google is your Friend, FL

Post Number: 4455
Registered: Aug-05
sooooooooooooooooooooo it is safer to underpower your subs than have headroom after all. lol
 

Gold Member
Username: Illuminator

USA

Post Number: 4040
Registered: Apr-05
What my point is, I am simulating heavily clipped output from an underpowered(I will use 'underpowered' in the sense that the amplifier's output is below that of the speaker's rated power handling capacity) amplifier and the speaker didn't blow.

You say hold it there for hours. Why? Very few people play their audio systems for that long, so it would have no real-real world application. I don't want to go through that, but I think it's safe to say that any damage being sent to the speaker from an underpowered heavily clipped amplifier, will be minimal if even existant.

Sure, you might say that the damage will accrue and eventually the speaker will start to sound poor. Not true, each time the car is turned off, the 'heat buildup' would dissapate.

In essence, clipped signals from an underpowered amplifier will not cause a speaker to blow.
 

Silver Member
Username: Naledge503

Portland, Oregon U.S.

Post Number: 125
Registered: Jun-06
James did you get that off bcae1?
 

Silver Member
Username: Naledge503

Portland, Oregon U.S.

Post Number: 127
Registered: Jun-06
Looks like james has been reading up on bcae1, lol.
 

Gold Member
Username: James1115

Ct

Post Number: 6098
Registered: Dec-04
yeah
 

Gold Member
Username: Basshead86

Google is your Friend, FL

Post Number: 4456
Registered: Aug-05
my point was......DC current from an AMPLE amp....haha....one that has the ability to power the speaker to its limits....will KILL a sub with DC.

bye bye:-)
 

Silver Member
Username: Wingmanalive

Greensburgh, PA US

Post Number: 153
Registered: Jun-06
I'm out. C-ya tomorrow.Upload
 

Silver Member
Username: Naledge503

Portland, Oregon U.S.

Post Number: 128
Registered: Jun-06
oops, i didnt read james last 2 post's otherwise i would have obviously known that...haha
 

Silver Member
Username: Alexv305

Tavernier, FL USA

Post Number: 362
Registered: Oct-05
When you say underpowered you mean WAY underpowered because driving an 800 watt RMS sub with a 400 watt RMS amp producing 800 clipped watts IS going to fry those coils pretty quick. What i think you were trying to say is a HEAVILY UNDERPOWERED subwoofer say 800 watts rms sub and recieving 10 watts square wave, then the sub has a chance at dissipating the heat caused by the improper cone movement..
 

Gold Member
Username: James1115

Ct

Post Number: 6099
Registered: Dec-04
if the sub is not underrated then yes, that is exactly right.
 

Gold Member
Username: Illuminator

USA

Post Number: 4041
Registered: Apr-05

quote:

A amp at full clip can produce double the power it is rated for. Therefor the voltage of the clipped signal is even higher. Lets say you have a 100 watt true power amp that same amp clipped at full could deliver upto 200 watts but the clipped square signal will produce moren then double the voltage of a 100 watt pure signal. Here is a formula.




So if you had that same 100 continous watt amp hooked up to a 200 continuous watt sub with pure clipped signal, it would be giving the sub 200 watts. The sub still shouldn't blow (unless you gave it hours). And that is basically what I am saying and what Perry is saying :-)

I think what needs to be defined is the rated output of the amp and the rated input of the sub.

Another way to put it: If the rated continous output of the amp is half of that of the sub, then a clipped signal will not harm the sub significantly because the sub would then be receiving it's full rated continous power. And if the amp is rated below that, then there's absolutely no problem with running pure clipped signals. If it is above it, however, (and I believe this is what is being said), then the sub will receive damage.

To put some numbers in.

Say you have a 500 watt rms amp and a 1000 watt rms sub.

0-400watts of clipped signal is fine, 400-500 is risky, anything above that is likely to blow the sub.

Better? :-)
 

Gold Member
Username: James1115

Ct

Post Number: 6100
Registered: Dec-04
if the sub is not underrated then yes, that is exactly right.
 

Silver Member
Username: Troy81

Tavernier, Fl Us

Post Number: 956
Registered: Mar-06
alex the subs wont burn unless it has time to heat up, and depending on the sub the faster it will heat up. like i said earlier i had my memph's over powered by 350dirty rms and they didnt blow, so as soon as you can explain that to me ill believe that dc current soley burns VCs and not over excursion and constant DC
 

Silver Member
Username: Alexv305

Tavernier, FL USA

Post Number: 363
Registered: Oct-05
Remember Jexx there are other factors into play with this such as excursion...When you play it with 200 watts RMS thats only the drivers ELECTRICAL handling... so not only is it going to heat up..It is also pushing its mechanical parts into overdrive with over excursion and heat adding to the risk..

Also really depends on the enclosure, free air, resistance, and alot of other factors. But it has been proven that people blow their subs from underpowering them... Why do you think those combo deals you buy from Car Audio shops blow so easy.. Usually because they arent matched up like they should be..
 

Gold Member
Username: Illuminator

USA

Post Number: 4042
Registered: Apr-05
Admittedly, I might have been a bit liberal with my numbers :P

In retrospect, I just realized we all agree that a clipped signal will blow a sub when the amp puts out a certain amount of power, but we were disagreeing at what point that happened. Is that correct?

Good discusssion guys, I enjoy this type of stuff; haven't been involved in something like this for a while. :-)
 

Gold Member
Username: James1115

Ct

Post Number: 6101
Registered: Dec-04
No Jexx because the fact that a square wave will produce more voltage then a clean wave so a clean wave at 200 watts will not have the amount of voltage as a clipped wave so therefore overheating the coil faster in minutes sometimes not hours. It all depends on the ratings of the sub and the quality of it.
 

Gold Member
Username: James1115

Ct

Post Number: 6102
Registered: Dec-04
I was talking to Muddy and we were saying how this is how Ecoustics used to be every day I know you remember that Jexx. I miss discussions like this:-):-):-)
 

Silver Member
Username: Alexv305

Tavernier, FL USA

Post Number: 364
Registered: Oct-05
Thank you again James...Your my hero!
 

Gold Member
Username: Illuminator

USA

Post Number: 4043
Registered: Apr-05
Yep, exactly. I don't think you had the opportunity to read my post right above yours, James. :P
 

Gold Member
Username: Basshead86

Google is your Friend, FL

Post Number: 4457
Registered: Aug-05
yes.a sub is rated with the idea of unclipped AC voltage in mind.


DD's are rated REALLY high from the cooling technology.

it it can't cool. then the sub is gonna fry with a fraction of the power.
 

Silver Member
Username: Alexv305

Tavernier, FL USA

Post Number: 366
Registered: Oct-05
I agree with your post on us disagreeing about what point the sub blows... LOL...But other than that...Good discussion..
 

Silver Member
Username: Naledge503

Portland, Oregon U.S.

Post Number: 132
Registered: Jun-06
I'm just sitting back and enjoying. This is a very good discussion. The best one i have seen since i joined ecoustics.
 

Gold Member
Username: James1115

Ct

Post Number: 6103
Registered: Dec-04
yeah Jexx I didnt read it before my post but I agree man this is prob the best Thread on this forum in 6 months:-)
 

Gold Member
Username: Basshead86

Google is your Friend, FL

Post Number: 4458
Registered: Aug-05
BEST THREAD AWARD

:-)
 

Gold Member
Username: Illuminator

USA

Post Number: 4046
Registered: Apr-05
Haha, yeah, those were good times.:-)
 

Gold Member
Username: James1115

Ct

Post Number: 6104
Registered: Dec-04
yeah man
 

Gold Member
Username: Safe_cracker

Chicago, IL US

Post Number: 1332
Registered: Jan-06
You see there is a difference between running a clipped signal or running your amplifier into clipping. Running a clipped signal will only produce distortion but will allow the sub and amplifier to behave normally. Now running an amplifier into clipping will result in the fets to stop switching resulting in a straight DC current to your subs, that will burn the sh!t out of them. If you read the statement about the momentum carrying the moving mass through its travel, it makes sense. Now if you ran a clipped input signal with tons of BB, then I believe thermal damage could occur but again that is because of the excessive current draw and not the clipped signal in general. If anyone is willing I have a program or two you can use on a laptop to run square waves to your subs? LOL... Polo.. :-O
 

Silver Member
Username: Troy81

Tavernier, Fl Us

Post Number: 958
Registered: Mar-06
im gonna sum up this amazingly helpful thread, square(distorted/clipped) waves will not blow your sub if they are not over powering it and not used constantly, they sound like crap and produce more heat but will not hurt your sub directly, the heat from this can and will eventually burn the VC's and depending on the heat dissipation of the sub is the time it takes, also, if you just play a constant DC voltage through a sub it will go one way and stop then make lots and lots of heat and burn the crap out of your VCs

what i got out of all this is a square wave sounds worse then it really is, literally sounds worse, and again, why clip your amp cuz it will prolly blow soon anyway, because theres definately not supposed to be DC current passing through the fets, but i would also say it would, in the case of good quality equipment( not sony xplode etc...), be alright to turn your gain and bb way up for a SPL competion or a short period of time. i said it would be alright to do that, i would never do it but it should be fine, now if clipping your amp drives it past the subs rms then thats defeating half the points of this thread and wil blow your sub on spot, just about. so basically try not to but if you do dont worry, as long as you dont do it for long periods of time.

thats what i got plus my opinion, if you dont like it, blow me hah




and my own question, if you use an occiloscope and find that your amp clips at high volumes, does it also clip at low volumes? if i were to use my knowledge i would say no it doesnt clip because the amp isnt trying to reproduce more signal then its getting
 

Bronze Member
Username: Th3pwn3r

Chicago, Illinois U.S.A

Post Number: 97
Registered: Jul-06
I wish lilrob was here to shed some light on this and give us the truth behind it all. :-)
 

Gold Member
Username: Basshead86

Google is your Friend, FL

Post Number: 4460
Registered: Aug-05
nice.^^^ lol
 

Gold Member
Username: Safe_cracker

Chicago, IL US

Post Number: 1335
Registered: Jan-06
"I wish lilrob was here to shed some light on this and give us the truth behind it all."


Upload
 

Gold Member
Username: B101

Queen City, NC USA

Post Number: 3513
Registered: Sep-05
well i didnt read the entire thing yet.. lol

dc = directed current = moves 1 way!
ac = alternating current = move back and forth = switches polarity..

a ac current should be sent to the voice coils, not a dc current...

:-O
 

Gold Member
Username: B101

Queen City, NC USA

Post Number: 3514
Registered: Sep-05
I love AC, and its the easiest way to get power to your house, not DC.. :-O

ohh I just read the entire post.... lol
 

Gold Member
Username: Basshead86

Google is your Friend, FL

Post Number: 4462
Registered: Aug-05
B!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!:-)
 

Gold Member
Username: James1115

Ct

Post Number: 6105
Registered: Dec-04
lolol^^^^ I bet he could offer a ton of insight:-)
 

Gold Member
Username: James1115

Ct

Post Number: 6106
Registered: Dec-04
it's funny that the guy who originated this thread has not said a word since.
 

Gold Member
Username: Basshead86

Google is your Friend, FL

Post Number: 4468
Registered: Aug-05
i just realized that^^^^ hmmmm.....lol
 

Gold Member
Username: Safe_cracker

Chicago, IL US

Post Number: 1336
Registered: Jan-06
"a ac current should be sent to the voice coils, not a dc current... "

Just because a person is playing a clipped "SIGNAL" doesn't mean there is DC going to the coils. It is not a clipped input signal that causes a amp to produce a straight DC current, the amp if very capable of playing such a signal. Now if the amp is cheap and does not have enough power to support it them there is where a straight DC voltage will ruin your day, lol. Funny, because I have seen damaged Fets cause the same thing from too low of an impedence. Polo. :-O
 

Gold Member
Username: Basshead86

Google is your Friend, FL

Post Number: 4469
Registered: Aug-05
i tried to say that earlier.^^^

found it:


quote:

i think the terms DC and clipped signal do not go hand in hand. you can have a clipped AC wave.

DC is when the sub only stays in one position. like a batt.


 

Platinum Member
Username: Glasswolf

Wisteria, Lane USA

Post Number: 11539
Registered: Dec-03
in regards to the OP, by not surpassing the thermal limits of the speaker, you won't cook the coil, even with a clipped signal, and your driver won't over-excurt even when clipped if you don't excede the mechanical limits, of course. However, those limits are reduced from the stated RMS ratings of the speaker when you have a clipped signal, because you will generate more heat.
What that quote neglected to mention was mechanical damage caused by a clipped signal when the speker loses it's linearity and rakes the coil along the edge of the motor structure, which can also happen.

You can damage a speaker while remaining within it's thermal and mechanical limits, but it's less common that this happens.

The fact is, most people run their subs with power very close to the rated limits of the speakers, and as such, when you do clip the signal, you're already "into the red" as it were.
 

Platinum Member
Username: Glasswolf

Wisteria, Lane USA

Post Number: 11540
Registered: Dec-03
I posted a reply to this thread and the board ate it.
I get tired of this crap, so I'm not going to retype the entire thing.

basically, the quote didn't account for damage caused by the speaker losing linearity with a clipped signal, which will shred a voice coil, though not as commonly as thermal damage does.
Most clipped signal damage is caused because people run their speakers at or close to the thermal limits of the speakers already, so when a signal is clipping, you're already into the red.

can you run a speaker all day with a clipped signal without causing damage? sure.
does that mean it's 100% safe to do so? nope.
 

Gold Member
Username: Basshead86

Google is your Friend, FL

Post Number: 4474
Registered: Aug-05
happened to me last night.^^^

i typed something up. and the hit post reply, and it brought me to the thread with no posted reply. i said WTF, so then i hiut the back button, and my words were erased from the reply box....pissed me off. lol
 

Bronze Member
Username: Super_mario

Post Number: 93
Registered: Mar-06
The only reason i didn't reaply was that i had to go to school and i got off too late to reaply until today. I see many posts that offer very valid points and this should end the debate. Thanks a million. If you must know this originated from its is on yahoo's ask questions thing and well... here's a link to the posted statements.

http://answers.yahoo.com/question/?qid=20060814161442AAQYsLJ&r=w&pa=FZptHWf.BGRX 3OFMhDFTVtYjnNuXkiUqw93PIef3QVoFp_vB74kV_rGxVWX5BrKtvUWWVs_tWR7PWNZCqw--#TcUvUmO 8ADOXpAGkqU7UHkycE1VDywudEDKrmUvLfIg.1nfklNWD
 

Gold Member
Username: Safe_cracker

Chicago, IL US

Post Number: 1340
Registered: Jan-06
Ya, I hate when it eats the stupid post, most of the time I hit back and it is there but lately even that is fricken gone. Wolf makes a good point and coupled with the fact most people do not know what to listen for,so tend to destroy there subs. My biggest petpeev is when you get into somones car and there mids/highs sound like a harmonica blown through water, bugs the sh!t out of me, lol. Polo.. :-O
 

Gold Member
Username: Redliner

Wilmington, Ma

Post Number: 2228
Registered: Jun-05
i typed one up last night about how troy said ac and dc are the same thing just switched and i wrote how he was wrong but it ate it on me so i gave up
 

Gold Member
Username: James1115

Ct

Post Number: 6107
Registered: Dec-04
Did the same thing to me last night aswell.
 

Silver Member
Username: Troy81

Tavernier, Fl Us

Post Number: 963
Registered: Mar-06
i didnt say ac and dc are the same thing, i said that ac current is dc current switching polaritys rapidly,
 

Gold Member
Username: Kd7nfr

Montpelier, ID United States

Post Number: 1664
Registered: Apr-05
I agree with Muddy.
 

Gold Member
Username: Basshead86

Google is your Friend, FL

Post Number: 4512
Registered: Aug-05
JAKE!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!:-):-):-):-):-):-):-):-)

and thank you. lol
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