[updated:LAST EDITED ON 01-13-03 AT 06:47 PM (EST)]The discussion has always been in the scope of amplifiers that were not clipping (verified with an oscilliscope, right? so ZERO clipping.. wow!)...
In the scope of having a decent quality sub and a proper enclosure.

This being the case, a larger amplifier will be always more dangerous than a smaller amplifier, because you are CLOSER to the thermal powerhandling of the subwoofer.
This is true, because as you increase your power... CLIPPED OR UNCLIPPED... you create more heat in the voice coil.

Period.

Where is your argument?
Here, apparently:
>
>Which furthers my stance that one should always
>buy a more powerful amp because, even though your gains may
>be set properly, you just can never say for sure if you were
>clipping. Therefore, it is better to err on the big side.
>
No, actually you just proved that if you have a bigger amp, you are closer to thermalling the sub anyways, inherently.
Therefore, it would take smaller amounts of clipping to send the subwoofer over that "threshhold".
The smaller amp is the safer amp, always.

The only ONLY downside to the smaller amp is less potential output.
Everything else is a positive.




>
> Like I
>said, I think there is something to controling the cone
>motion sufficiently, and until I have reason to believe
>otherwise, I will continue to. I thought I gave good
>argument for this already?
>
Again then, the low-volume comparison.
Two scenarios:
One) You are listening to music at a low volume level. Does your music inherently go to mush, where as at high volumes it sounded accurate and clear?
Two) You are listening to music at high volume levels.. and there are broad dynamics in the music.. big swells of bass drums.. and then very faint, background bass...
Does the background bass sound bad, uncontrolled, and sloppy, where the loudest stuff sounds good?

Obviously not...

Controlling the cone motion accurately is done by:
1) proper loudspeaker driver design... ie. an accurate sub
2) proper enclosure design... ie. box built for the sub and the music
3) amp configured properly... ie. not set to clip audibly

>
>"There is a fallacy that a heavy cone will produce better
>bass. WRONG! There is also the fallacy that a stiff cone
>suspension means higher power handling. WRONG AGAIN! The
>truth is that if the cone is heavy, it will not react
>quickly to the input signal. Hence without the application
>of considerable wattage, the signal will be gone from the
>line before the cone can move and thereby causing an
>undesirable noise, kind of a flopping honk sound. Not to
>mention the other restrictions placed on a speaker with a
>heavy cone. The same thing can happen with a suspension that
>is too stiff." (Thomas P. Colvin -- Musicians Hotline)
>

I already replied to this already...
This is completely inaccurate and out of context relative to the discussion.
This has nothing to do with woofer reliability..
This has everything to do with loudspeaker driver design, and the trade-offs that are available in designing a hi-fidelity driver.
It has nothing at all to do with powerhandling.

 

[updated:LAST EDITED ON 01-13-03 AT 06:44 PM (EST)]Thanks for stopping by Dan. Glad to know I don't have to worry about feeding my Brahma "only" 1000rms. j/k

I saw you posts on transient response and mass vs inductance on CAF a few weeks ago. Kinda got lost in it, but rereading that info without the back and forth really helped. I thought that you just made up for the mass with the massive motor. Now I have much better understanding how inductance effects response. BTW, the Brahma responding up to 13k - amazing.

For anybody that thinks you shouldn't underpower a sub or that heavy subs aren't for SQ, I submit my Brahma install. Heavy, underpowered sub - has excellent SQ and still hasn't blown.

http://www.sounddomain.com/id/jimi7

 

Running a Pioneed Premier DEH-P940MP, JBL bp1200.1, and a Brahma 12 here myself, had the brahma almost a year now, and it has yet to blow from the mere 1200 watts it's getting

 

I just want to confirm that you understand that what you are quoting from the fine Mr. Thomas P. Colvin is completely misapplied, out of context, and off topic, with respect to our conversation...

I thoroughly responded to th quote from Mr. Colvin that you posted earlier...
Which you completely ignored, apparently...
As you continue to post the quote from him!
(and in fact, continue to try to draw correlations between power level and cone control!)


>
>If you want proof, contact Thomas P. Colvin who said, "There
>is a fallacy that a heavy cone will produce better bass.
>WRONG!
>
His point here is because moving mass directly affects Fs and VAS, two factors that directly correlate to a subwoofer's low bass potential.
It doesn't tie to powerhandling... it ties to methods of acheiving a low Fs without using inherently heavy cone, former, windings, or mass-adding techiques. Loudspeaker driver design issues.
Trust me, I am familiar with them...

>
>There is also the fallacy that a stiff cone
>suspension means higher power handling. WRONG AGAIN!
>
His point here ties to the relationship between the resistance against cone excursion and the possibilities of bottoming the subwoofer out... the mechanical powerhandling of the subwoofer if you will, which is completely independent of electrical powerhandling (which is half of his point, I am sure)...
Inherent in the driver itself, if you have a very low VAS (suspension compliance), it takes more power to reach maximum excursion levels than if you have a higher VAS.
The other half of his point, I am sure, was to suggest that you can have the same level of "mechanical powerhandling" in a subwoofer with a higher VAS.. because it matters not what the subwoofer does by itself, in free-air representation... what matters is what the subwoofer/enclosure combination perform like, together... and the enclosure itself augments the suspension of the subwoofer (dynamically however... you need to be aware of how it augments the subwoofer by frequency now!)
His point is valid...
But it doesn't relate to thermal powerhandling...
And I went to great lengths to allow you to make statements that would have allowed you to slip through this loophole, ie. "I played a 20Hz tone in my large box tuned to 50Hz..."


>
>The
>truth is that if the cone is heavy, it will not react
>quickly to the input signal. Hence without the application
>of considerable wattage, the signal will be gone from the
>line before the cone can move and thereby causing an
>undesirable noise, kind of a flopping honk sound.
>
So his point here is that you might design a loudspeaker driver so poorly that it takes significant amounts of power to get it moving, and even then, it results in a sloppy sounding driver.
This isn't anything the world didn't know, and it's one reason why people don't design subwoofers this way...
Particularly JL Audio, who has been KNOWN for revolutionizing the industry with small box subs that DIDN'T accomplish small VAS numbers by using high mass... to the contrary, they used lightweight, accurate cones, yielding both high quality sound, in small enclosures.
This was a 12W6 you had, right?
Bear in mind, the W6 series has earned JL more industry awards in design, engineering, and performance than any other subwoofer they have ever made... (although the W7 is IMO more deserving... and given the same amount of time, I am sure will prove true)

>
>Not to
>mention the other restrictions placed on a speaker with a
>heavy cone. The same thing can happen with a suspension that
>is too stiff." (Thomas P. Colvin -- Musicians Hotline)
>http://www.musicianshotline.com/archive/tech/reconing.htm
>
The suspension is an inherent restriction on cone movement... this has nothing to do with powerhandling, and the degree will vary from subwoofer to subwoofer.
Moving mass ("heavy cone".. but also voice coil windings, former, etc) is directly tied to VAS as well.
But these are loudspeaker design parameters.

Regardless of all this, any subwoofer...
Even one that is poorly designed..
Will fail less often on LESS power than it will on MORE power.

Is your argument that heavy cone / stiff suspension = less cone movement = more heat = premature failure?
If you have less power, you have less heat.. regardless of cone movement. Period.



>Until you disprove this, I only need to keep requoting it at
>the question of, "how can a sub be blown with clean power?"
>


Well, there you go (AGAIN!).
Not disproven, HE is correct.
YOU don't UNDERSTAND what he is discussing...
(or you wouldn't have posted it)

Talk about "out of context"...

Just look at Mr. Colvin now, he's quite upset! -->

 

why dont you people go outside and get a breath of freshair. how does a person have so much time on their hands, i have no idea. all 5 pages at the end of this thread are worthless. get out of the chair.

 

>why dont you people go outside and get a breath of freshair.
>how does a person have so much time on their hands, i have
>no idea. all 5 pages at the end of this thread are
>worthless. get out of the chair.

I am offended...
Seriously though, if you read my posts on this page (I don't know anything about the preceeding four! ), you will hopefully understand..
I think we are all in wrap-up mode, the points have been made, and even the arrogant RanDawg is conceding..

His recent bickerings are simply over trivial semantics and miscomprehensions of his.


But if you are wondering, personally I am involved in the final throws of a critical project, 2 years in the making, several teams of people handing off the baton to keep things going nearly 24/7 so that we hit our implementation deadline... I've just been checking in when I have downtime at work, and I type about as quick as I talk, so words go down fast, it's no major time expense, and it helps pass 12-18 hour days (you can imagine the post-impementation time off I am building up! )
In fact, I understand many forumgoers hit the threads while at work.

 

RanDawg, I'm getting a little lost here. I can't figure out your position or if it's changed from your original position. Probably just a result of engaging in 5 different arguments simultaneously, however it seems like the rest of the guys are being consistent. That may just because of I'm familar with their positions and the concept of subs blowing due to lack of power is new to me.

Assuming you don't have a defective driver or an enclosure problem and/or an appropiate subsonic filter (if applicable), would you agree with the following?

1) "Underpowering" isn't bad unless "underpowering" results in clipping to the point of "overpowering" the sub.
2) Clipping alone won't harm a sub, unless that clipping results in "overpowering" the sub.
3) If a 200rms sub is truly producing 200rms, then it cannot blow a 300rms sub.
4) Overpowering a sub is okay, so long as you don't truly exceed the subs rms rating (momentary peaks excepted).
5) Neither underpowering or overpowering is more dangerous to a sub per se. It's real power (clipped or unclipped) that we need to be concerned about.

If you agree with these statements, then I think that would put you in agreement with David Navrone, GeoLemon, Richard Clark, Tracy (from Kicker), Dan Wiggins and numerous posters to this thread.

 

>Running a Pioneed Premier DEH-P940MP, JBL bp1200.1, and a
>Brahma 12 here myself, had the brahma almost a year now, and
>it has yet to blow from the mere 1200 watts it's getting
>

That's definately one of the most popular car audio subwoofer set-ups around (at least on the net). I brought that up in an earlier post - why are so many people running this set up with great sucess if underpowering killed subs? You'd think there would massive failure rates if lack of power killed subs.

BTW, I have Pioneer 9300 - great minds think alike. LOL

 

>why dont you people go outside and get a breath of freshair.
>how does a person have so much time on their hands, i have
>no idea. all 5 pages at the end of this thread are
>worthless. get out of the chair.


You just certified yourself as an idiot. Have you even read the last five pages? They contain more excellent posts and information than I have seen in one place. Geo has time and again written EXCELLENT posts arguing our posistion.

Dan's post alone was worth wading through the entire thread. But I guess that applies to only those with at least a little technical apptitude.

Go find a prybar and try to get that foot out of your mouth.

 

ok u people seriously need to stop this, get up and get on with things. i wish i could close this topic already. i know many people have posted endless info, but enough is enough. dont u people have jobs? my mailbox was filled with 125 new messages just from this topic alone since last nite . i mean come on, give it up. i dont understand how y'all can sit there and type out novels at a time at ur job or where ever u are...

 

PS: if i get flamed for posting what i just did, get over it. im not a audio genious, physics major and whatever u people are. maybe if u would dumb it down for us begininers i could understand what y'all are saying.

 

>PS: if i get flamed for posting what i just did, get over
>it. im not a audio genious, physics major and whatever u
>people are. maybe if u would dumb it down for us begininers
>i could understand what y'all are saying.


Haha... No problem Optikal.. I completely understand where you are coming from! I hate it too, when threads get so long that you don't want to bother reading the whole thing. I am 100% with you!


Here's a good summarization:

The less power you present to a subwoofer, the safer it is for your subwoofer... although you will also have less output, the lower you go.

If you clip your amp, you could send up to two times the rated RMS power of the amp through your subwoofer... (although in reality it is less than that)
If that clipped power exceeds your subwoofer's RMS power rating, you could indeed cause thermal damage to the subwoofer..
But that's not because you were using too small of an amp, it's actually because you made your amp put too much power through the sub... not too little.

However, if you have a very small amp, and you are clipping it.. but even the clipped power doesn't exceed your subwoofer's power rating (and as long as the sub is in a proper enclosure), you simply won't harm it.

But you shouldn't clip your amp anyways, because it sounds bad.


So, it's not that "too little power" kills subwoofers at all..
In fact, the less, the safer.

It's not "clipping causes damage" either, because you could clip the snot out of the amp, and still not harm the sub, as long as the clipped power remained at safely low enough power levels for the sub to handle.

There's only two things that kill subwoofers:
1) Too much power (causing thermal damage).
2) Too much excursion (user error - enclosure/music/power level issue, causing mechanical damage from bottoming or other physical collision)

Concise? That really does sum up what we have discussed.

 

thats what i thought and have been told by tempe and other over at termpro.com and u just confirmed it. thanx bro

 

Hey RanDawg how about you just give up already. You've been proven wrong many times throughout this LONG thread. You've even made me sign-up just to contribute. One last time...just GIVE UP!

John

 

>>why dont you people go outside and get a breath of freshair.
>>how does a person have so much time on their hands, i have
>>no idea. all 5 pages at the end of this thread are
>>worthless. get out of the chair.
>
>
>You just certified yourself as an idiot. Have you even read
>the last five pages? They contain more excellent posts and
>information than I have seen in one place. Geo has time and
>again written EXCELLENT posts arguing our posistion.
>
>Dan's post alone was worth wading through the entire thread.
>But I guess that applies to only those with at least a
>little technical apptitude.
>
>Go find a prybar and try to get that foot out of your mouth.

i was being sarcastic. actually i was almost kidding. you just certified yourself as an idiot. why dont you ease up a little bit. well i guess that only applies to people that have a life. find a crowbar and get your nose out of everybody's ***. seriously man, you just made that post apply to yourself. ;-)