What failed in this Audio system? Blown speaker?

[suchamoneypit]

So I have a friends car wired up with subs, amp, sub box. Recently he opened his trunk to the sub box pouring out smoke. My first thought was the cheap plastic connector area on the sub box got too hot and melted from heavy use. The speaker in question was a kicker comp powered alone by a kicker 600w amp. I opened up the sub box and the connector area is fine. The amp seems fine. The speaker seems rough when I manually depress the cone area, not like it did when I got it. This probably means a blown speaker, but how?

 

Is this not a higher end sub with a nice amp supplying it power? The gain was around 90%. Just curious of exactly why the speaker blew.

[emosun]

says 600w peak 300w rms

meaning yeah you can blow it easy with a 600w amp

[NinjaQuick]

the speaker blew because of the heat of the voice coil.

 

 

The amp killed it or you were running it too long at full power, like on a 20hz sine wave.

 

Was the amp hooked up to a preamp or to an amplified signal.

 

[suchamoneypit]

1 hour ago, NinjaQuick said:

the speaker blew because of the heat of the voice coil.

 

 

The amp killed it or you were running it too long at full power, like on a 20hz sine wave.

 

Was the amp hooked up to a preamp or to an amplified signal.

 

The amp was hooked up to a preamp directly from the aftermarket radio.

[Guest]

Yeah the AMP blew the subwoofer, which is only rated at 600w peak. NOT rms. If you run a sub like that its definitely going to blow when the AMP can deliver more than the peak of the sub. 

[mr moose]

Although a very controversial topic, clipping or extended DC driving a speaker will kill the coil.  Regardless of an amps rating and a speakers rating, if you do not drive the audio to the point of distortion through the speaker or clipping in the amp, then you are not likely to kill the speaker.   Be aware that not all clipping or over driving is immediately audible to the untrained ear.

[Guest]

On 6/19/2018 at 8:02 PM, mr moose said:

Although a very controversial topic, clipping or extended DC driving a speaker will kill the coil.  Regardless of an amps rating and a speakers rating, if you do not drive the audio to the point of distortion through the speaker or clipping in the amp, then you are not likely to kill the speaker.   Be aware that not all clipping or over driving is immediately audible to the untrained ear.

600W RMS going to a 300RMS woofer is gonna blow whatever volume above 0. I wouldn't even think about touching the SPL. Cheap woofer though, you get what you pay for. 

[mr moose]

1 minute ago, RorzNZ said:

600W RMS going to a 300RMS woofer is gonna blow whatever volume above 0. I wouldn't even think about touching the SPL. Cheap woofer though, you get what you pay for. 

You'd think that, but it's common to run higher rated amps than drivers because amp clipping is harder to hear and can do as much damage as driver clipping. 

I regularly run 600Watt RMS  amps at about 50% into 150Watt RMS drivers.  

[Guest]

On 6/19/2018 at 8:31 PM, mr moose said:

You'd think that, but it's common to run higher rated amps than drivers because amp clipping is harder to hear and can do as much damage as driver clipping. 

I regularly run 600Watt RMS  amps at about 50% into 150Watt RMS drivers.  

Depends on the setup tbh. I just wouldn't be comfortable with that. Like it would run and 150w RMS would be fine, but I wouldn't run it for a while. You also have to take into account that the sub probably blew because it was cheap and nasty - Kicker are not a good brand and their RMS can be unreliable. I really only go with Rockford Fosgate or Pioneer (Just because my unit is Pioneer tbh and I've had no bad things from them). 

 

[mr moose]

1 minute ago, RorzNZ said:

Depends on the setup tbh. I just wouldn't be comfortable with that. Like it would run and 150w RMS would be fine, but I wouldn't run it for a while. You also have to take into account that the sub probably blew because it was cheap and nasty - Kicker are not a good brand and their RMS can be unreliable. I really only go with Rockford Fosgate or Pioneer (Just because my unit is Pioneer tbh and I've had no bad things from them). 

 

It could easily be a shit woofer/faulty woofer. That is as true as any other possibility.   I find most of the Ratings on car audio to be BS, has been since I can remember (back into the 80's easily).   

 

For the record. I am a live sound engineer and setup studios/PA on the side.  My personal wedding/party small band rig consist of a single amp capable of delivering 700Watts RMS into 4 ohms x2 channels and 4 12" 150Watt RMS drivers.  I regularly push 100-103db on the dance floor.

[Guest]

58 minutes ago, mr moose said:

It could easily be a shit woofer/faulty woofer. That is as true as any other possibility.   I find most of the Ratings on car audio to be BS, has been since I can remember (back into the 80's easily).   

 

For the record. I am a live sound engineer and setup studios/PA on the side.  My personal wedding/party small band rig consist of a single amp capable of delivering 700Watts RMS into 4 ohms x2 channels and 4 12" 150Watt RMS drivers.  I regularly push 100-103db on the dance floor.

Keep in mind though its easy to get 90-100dbs on even a low power system, getting 130+ is a lot trickier. Thats a pretty nice amp for 700W, but i'm more of a car audio guy so I don't really know about that market. I usually do car audio installs on the side. I'm pretty good but a sound engineer sounds more impressive, like depending on how you've wired it up the resistance would be more suitable for that setup, so keep in mind this is just one woofer connected to a mono amp. 

 

To get an idea though of the disparity of my knowledge between me and you I run three Fosgate punch amplifiers in my car, but for my home/party audio and whatnot I have a Denon PMA-250 with 25W/Ch RMS with a couple Warfdale 100W speakers. Mainly all about wiring not so much about the technical side!

[mr moose]

14 minutes ago, RorzNZ said:

Keep in mind though its easy to get 90-100dbs on even a low power system, getting 130+ is a lot trickier. Thats a pretty nice amp for 700W, but i'm more of a car audio guy so I don't really know about that market. I usually do car audio installs on the side. I'm pretty good but a sound engineer sounds more impressive, like depending on how you've wired it up the resistance would be more suitable for that setup, so keep in mind this is just one woofer connected to a mono amp. 

 

To get an idea though of the disparity of my knowledge between me and you I run three Fosgate punch amplifiers in my car, but for my home/party audio and whatnot I have a Denon PMA-250 with 25W/Ch RMS with a couple Warfdale 100W speakers. Mainly all about wiring not so much about the technical side!

The math and physics is the same for all audio.  I used to be in car audio a little bit years ago, moved through home audio but all the time I have been big into live sound.   I designed and built all the speakers in my studio/theatre, I have built several guitar amps and one car amp.  But by far the best thing is building custom speakers for weddings.

 

All amplifiers are voltage sources,  the resistance of the speaker determines the current flow and thus the wattage being dissipated.   Depending on sensitivity, the total SPL at any given distance can vary largely.    The reason car systems get to 130 is because it is very close to the drivers and usually in an enclosed space.  Maintaining 106db (which is what I aim for at the mixing console) is usually about 10-15 metres from the drivers and in an open environment or large hall. I know I can push harder than 106 but that's when I start getting into the danger zone of breaking things.  

 

EDIT: and yes the amp is beautiful, I bought it back before class D amps became a thing, it weighs 40Kg.  Seriously, it's like lugging 2 bags of concrete into the venue.

[Ahoy Hoy]

18 hours ago, emosun said:

says 600w peak 300w rms

meaning yeah you can blow it easy with a 600w amp

LOL WRONG!
Plus up to 300W maximum power @ 4 ohms (75 x 4) to deliver powerful audio. Up to 300W (150 x 2) maximum power @ 4 ohms bridged.

[Ahoy Hoy]

13 hours ago, RorzNZ said:

Yeah the AMP blew the subwoofer, which is only rated at 600w peak. NOT rms. If you run a sub like that its definitely going to blow when the AMP can deliver more than the peak of the sub. 

Wrong read the spec of the amps its 300Watts at 4 ohms

[Ahoy Hoy]

11 hours ago, mr moose said:

It could easily be a shit woofer/faulty woofer. That is as true as any other possibility.   I find most of the Ratings on car audio to be BS, has been since I can remember (back into the 80's easily).   

 

For the record. I am a live sound engineer and setup studios/PA on the side.  My personal wedding/party small band rig consist of a single amp capable of delivering 700Watts RMS into 4 ohms x2 channels and 4 12" 150Watt RMS drivers.  I regularly push 100-103db on the dance floor.

The fact you said that shows you dont know much. Sensitivity is the biggest dependant when talking about sound level. Dont even mention the resistance of the speakers. 

[Ahoy Hoy]

18 hours ago, suchamoneypit said:

So I have a friends car wired up with subs, amp, sub box. Recently he opened his trunk to the sub box pouring out smoke. My first thought was the cheap plastic connector area on the sub box got too hot and melted from heavy use. The speaker in question was a kicker comp powered alone by a kicker 600w amp. I opened up the sub box and the connector area is fine. The amp seems fine. The speaker seems rough when I manually depress the cone area, not like it did when I got it. This probably means a blown speaker, but how?

 

Is this not a higher end sub with a nice amp supplying it power? The gain was around 90%. Just curious of exactly why the speaker blew.

From my experience, the fire in speakers is normally caused by overheating. Either the glue holding the dust cover/surround/cone. Or one of those since there all paper of fabric have caught on fire. Or you've gone super hot and the voice coil has melted. But it won't be that since you can depress the cone and if the voice coil melted it would probably lock up.

Probably not worth your time reconeing so just buy a replacement and swap it in.

[Guest]

14 minutes ago, Ahoy Hoy said:

The fact you said that shows you dont know much. Sensitivity is the biggest dependant when talking about sound level. Dont even mention the resistance of the speakers. 

Not really, resistance alters the amount the amp can provide to the speaker. Subs wired up for 2 ohms will be louder than 4 ohms from the same amp. Remember P = VI, R = V/I. So the more power you put into the system for the same resistor will increase the amps, likely damaging the cone. Sensitivity doesn't count for much once you get above 90 decibels. 

16 minutes ago, Ahoy Hoy said:

Wrong read the spec of the amps its 300Watts at 4 ohms

Its 4CH anyway really so we're both wrong. It still obviously took too much power and blew up. 

 

13 minutes ago, Ahoy Hoy said:

From my experience, the fire in speakers is normally caused by overheating.

What do you think causes heat? Its a resistor. 

[Ahoy Hoy]

3 minutes ago, RorzNZ said:

Not really, resistance alters the amount the amp can provide to the speaker. Subs wired up for 2 ohms will be louder than 4 ohms from the same amp. Remember P = VI, R = V/I. So the more power you put into the system for the same resistor will increase the amps, likely damaging the cone. Sensitivity doesn't count for much once you get above 90 decibels. 

Its 4CH anyway really so we're both wrong. It still obviously took too much power and blew up. 

 

What do you think causes heat? Its a resistor. 

You know your just proved you knew your own point which you originally got wrong.

 

What am i wrong about i opened the two links provided looked at the specs one says the speaker is 300Watts at 4 ohms the amp says when in bridged modes its 300 watts at 4 ohms. OH, MY GOD, HE USED TOOO MUCH POWAH!!!!! (no he didnt)

 

The fact he ran it at max in a warm car and the sub is probably located in the boot in a fury box which is acting like a little hot box for it. Probably isnt getting adequate cooling and the fact its reasonably cheap ish speaker from a low down manufacturer so probably isn't made to be super durable and to run at hot temperatures.
 

[Guest]

2 minutes ago, Ahoy Hoy said:

You know your just proved you knew your own point which you originally got wrong.

 

What am i wrong about i opened the two links provided looked at the specs one says the speaker is 300Watts at 4 ohms the amp says when in bridged modes its 300 watts at 4 ohms. OH, MY GOD, HE USED TOOO MUCH POWAH!!!!! (no he didnt)

 

The fact he ran it at max in a warm car and the sub is probably located in the boot in a fury box which is acting like a little hot box for it. Probably isnt getting adequate cooling and the fact its reasonably cheap ish speaker from a low down manufacturer so probably isn't made to be super durable and to run at hot temperatures.
 

I'm not here to prove a point i'm here to help the OP. Don't talk about stuff you don't know about just to try and argue. 

[Ahoy Hoy]

8 minutes ago, RorzNZ said:

Not really, resistance alters the amount the amp can provide to the speaker. Subs wired up for 2 ohms will be louder than 4 ohms from the same amp. Remember P = VI, R = V/I. So the more power you put into the system for the same resistor will increase the amps, likely damaging the cone. Sensitivity doesn't count for much once you get above 90 decibels. 

 

Because this one pissed me off the most its getting its own post. 
"Subs wired up for 2 ohms will be louder than 4 ohms from the same amp" Depends on the sensitivity of the speaker.

"Remember P = VI, R = V/I" congratulations you turned up to a single physics lesson

 

"So the more power you put into the system for the same resistor will increase the amps, likely damaging the cone." struggling with the English on this one. So your saying the more power applied to the speaker will mean the app is giving more power. ?????

"Sensitivity doesn't count for much once you get above 90 decibels. " Just no just dam no. You ever seen the graph for. Power vs SPL. It logarithmic. Low SPL doesnt need much power then it increases and increases then suddenly to gain one decibel you need to double/triple the power. When you start getting to that point you're going to love your high sensitivity speakers as it means you are using less power.

[Ahoy Hoy]

3 minutes ago, RorzNZ said:

I'm not here to prove a point i'm here to help the OP. Don't talk about stuff you don't know about just to try and argue. 

You answered his question wrong wheres the help in that. I explained my points with reasons why and then suggested a course of action.

[mr moose]

1 hour ago, Ahoy Hoy said:

The fact you said that shows you dont know much. Sensitivity is the biggest dependant when talking about sound level. Dont even mention the resistance of the speakers. 

Good thing you read all the posts before pretending to be better than other people:

11 hours ago, mr moose said:

The math and physics is the same for all audio.  I used to be in car audio a little bit years ago, moved through home audio but all the time I have been big into live sound.   I designed and built all the speakers in my studio/theatre, I have built several guitar amps and one car amp.  But by far the best thing is building custom speakers for weddings.

 

All amplifiers are voltage sources,  the resistance of the speaker determines the current flow and thus the wattage being dissipated.   Depending on sensitivity, the total SPL at any given distance can vary largely.    The reason car systems get to 130 is because it is very close to the drivers and usually in an enclosed space.  Maintaining 106db (which is what I aim for at the mixing console) is usually about 10-15 metres from the drivers and in an open environment or large hall. I know I can push harder than 106 but that's when I start getting into the danger zone of breaking things.  

 

EDIT: and yes the amp is beautiful, I bought it back before class D amps became a thing, it weighs 40Kg.  Seriously, it's like lugging 2 bags of concrete into the venue.

 

Because had you bothered to read everything you would have realised that we where talking about wattage,  what determines the wattage dissipated by a speaker is not the total power an amp can deliver but the voltage of the amp and the impedance of the speaker.  That is why mentioning resistance is important when trying to ascertain if the speaker was dissipating too much power. 

[Ahoy Hoy]

18 hours ago, mr moose said:

Good thing you read all the posts before pretending to be better than other people:

 

Because had you bothered to read everything you would have realised that we where talking about wattage,  what determines the wattage dissipated by a speaker is not the total power an amp can deliver but the voltage of the amp and the impedance of the speaker.  That is why mentioning resistance is important when trying to ascertain if the speaker was dissipating too much power. 

Your original point was how your amp and speaker set up can do a certain SPL. But you didn't mention the sensitivity of the speaker which is the main factor in SPL. (of course as long as the amp is powerful enough)

 

Saying anything to do with power and saying that will be good for this SPL you need to say the sensitivity otherwise its a meaningless point to make.

 

a speaker which produces 100dB at 1 Watt at 1 meter compared to a speaker which is 1dB at 1 Watt 1meter. They both could do 100dB but one takes a load more power.

See how that is better than saying this speaker does 100dB and so does this speaker.

[mr moose]

4 hours ago, Ahoy Hoy said:

Your original point was how your amp and speaker set up can do a certain SPL. But you didn't mention the sensitivity of the speaker which is the main factor in SPL. (of course as long as the amp is powerful enough)

I only mentioned SPL in that post because quite often when I talk about the power levels I run stuff at,  people tend to say things about how I am not getting the most out of it or the volume isn't good enough at those wattage's etc.   Sometimes I even hear silly comments about headroom and transparency in music.

AND no it wasn't the "original" point of my post at all, it was a sentence at the end all on its own.  The rest of the sentence if you read in context with the discussion makes perfect sense.

 

4 hours ago, Ahoy Hoy said:

Saying anything to do with power and saying that will be good for this SPL you need to say the sensitivity otherwise its a meaningless point to make.

 

a speaker which produces 100dB at 1 Watt at 1 meter compared to a speaker which is 1dB at 1 Watt 1meter. They both could do 100dB but one takes a load more power.

See how that is better than saying this speaker does 100dB and so does this speaker.

Except that this conversation is about why the speaker blew, how loud it was is irrelevant. I thought I made that point a bit clearer in the follow up discussion.

[emosun]

On 6/19/2018 at 3:09 PM, Ahoy Hoy said:

LOL WRONG!

always a convincing method for gauging someones human interaction skills.