power to cab ratio?

[vicenzajay]

Jay, I understand what you're trying to say, and you're right in that it is important to give practical advice. Do understand, though, that what Mark and I said was meant as, and was, practical advice. For example, when I say in an early point that the important thing is not the amp:cab ratio but the issue of whether the OP has enough power for his needs, that's an eminently practical consideration. When Mark says that clipping per se is not the problem, that's practical advice too, because it encourages you to think about the real issues, and hekps you to understand how rigs work and how you can avoid future problems.

Regardless, let's leave things here, if you're agreeable. Peace.
.

I'm happy to leave it here - hope you're having a good weekend full of music!

 

[Mark Reccord]

I agree with Richard's last post - in that usually people that go personal with something have a flimsy argument. For that I apologize. I never claimed to have either of your technical knowledge...and never claimed to be able to give anyone the scientific equation of why something happened.


However, my words were called "nonsense", a ridiculous allegory between a 50 watt amp and an 800 watt sub was used. And the words of too many other people quite expert in this field were called "wrong" out of hand. So to be honest - I felt as if this had gone personal on me first. To add to that - the last post just alluded to the fact that I lack "elementary courtesy". Lot's of personal things going on here.

I apologize for using the word nonsense, it was inappropriate. It wasn't my intention to be rude. However, I will not back down on my assertion that a lot of the so called experts in the field (including manufacturers) are providing incorrect information, or at least not telling the whole story. I can back any of my claims up both mathematically and from personal experience. So can Bob Lee, Bill Fitzmaurice, Jerrold Tiers, etc. We all design/build amplifiers/speaker systems for a living. The other guys have way more experience than I do, but you'll see a lot of agreement between my posts on the subject and theirs.

I'm sorry that we don't agree...but Marc, the 4 people I know who have blown speakers here in town have ALL done it with underpowered amps pushed too hard. That's why I'm not budging on my advice to the poster or my claim that most speakers damaged are not damaged simply as a result of having an amp that is rated at a higher wattage than the speaker. Of course his amp does not "intrinsically" possess the danger of blowing his speaker cabinet "because" it is underpowered. That's not what I said - or meant. What I said was meant to warn the poster that it is very possible (and has happened often) to damage a speaker with an amp that is powered at a wattage below the rated wattage of the speaker. Your point about the volume he needs being the determining factor is very salient - however, my intent was to inform him of what he might face in the future.

We're really not that far apart. Though I will still maintain that the vast majority of cone speaker failures are excursion related. In my career, I've personally reconed hundreds of drivers and seen just about every possible type of failure. I can count the thermal failures on my digits... That being said, it's easy to exceed excursion limits and tear a surround with way less than the driver's 'rated' power, clean or clipped. There are a lot of factors at play in the interactions of speakers and amplifiers and I feel that a lot of the time, explanations are simplified so much that they aren't very useful. Which is why you can see my first post in this thread in various versions all over TB.

My original post in this thread was to disagree with the statement that "clipping and square waves" don't affect speakers. That's like saying that air doesn't affect humans. It was a post that did not enlighten or (in my opinion) properly warn or address what can (and does) happen in the poster's situation if he/she is not careful.

.....Snip a little for brevity.......

Out here,
Jay

Again, it may be a point of semantics, but speakers really don't care about waveform, so in a sense the statement is right. However, like what you're saying, it needs to qualified to tell the whole story. I regularly see people on TB who think that they can actually put 2x rated power into their speakers as long as it's clean, because no one has explained to them that there's a difference between using an amp rated at 2x the driver's rating and actually putting that much power into the drivers. I've also seen things like Richard mentioned, with people looking to find a lower power rated cabinet so that they're not 'underpowering.'
I also see a lot of people who think that a cabinet's power rating is a required amount of power for the cab. All of this is a result of oversimplification. I'm not looking to make anyone into a speaker expert either, but I am trying dispel some of the many misconceptions floating around (probably not all that successfully).

At any rate, I do apologize for being rude and hope this helps clarify my position and what I'm trying to do.

That's Mark with a 'K' BTW....

 

[Espidog]

Oh God in the garden, not this again.....

...and you just know it won't be the last time it gets dragged up.

BassPlayer48, I bet you had no idea what a can of worms you were opening up with this post!

 

[link wray]

I agree that clipping does not hurt drivers... but i am not shure this also applies to crossover-filters. Those filters also are often rated (far) less watts/thermal handling than the woofers in a typical cab.

 

[Munjibunga]

You'll be fine as long as you don't run your amp into clipping. This means that your amp can only put out so much power, and if you keep turning it up, you run the risk of damaging your speakers once the amp starts to clip. Others will say that those squarish waves can't hurt your speakers, but at 300 watts, they can.

Bottom line, I ran my WT-300 (something like 180 watts @ 8 ohms) into my 8-ohm D-410 XLT (rated at 700 watts) for years and never had an issue. I just never tried to get more volume out than the amp would produce. So if you pay attention to your clip indicator, you won't have any problems.

For future reference, it's best to have an amp rated at about one-and-a-half to two times the power capability of your cab(s) for extra headroom, but it's not really necessary.

 

[Bassman62]

You'll be fine as long as you don't run your amp into clipping. This means that your amp can only put out so much power, and if you keep turning it up, you run the risk of damaging your speakers once the amp starts to clip. Others will say that those squarish waves can't hurt your speakers, but at 300 watts, they can.

Agree 100%, in the past when people thought that their speakers were farting it was actualy the amp in most cases breaking up!

 

[Mark Reccord]

You'll be fine as long as you don't run your amp into clipping. This means that your amp can only put out so much power, and if you keep turning it up, you run the risk of damaging your speakers once the amp starts to clip. Others will say that those squarish waves can't hurt your speakers, but at 300 watts, they can.

No one ever said that they can't hurt your speakers, rather that in some situations they won't and in some situations they will.
The whole 'clipping destroys speakers' thing is far too simplistic to be useful in the real world.

 

[vicenzajay]

We're really not that far apart. Though I will still maintain that the vast majority of cone speaker failures are excursion related. In my career, I've personally reconed hundreds of drivers and seen just about every possible type of failure. I can count the thermal failures on my digits... That being said, it's easy to exceed excursion limits and tear a surround with way less than the driver's 'rated' power, clean or clipped. There are a lot of factors at play in the interactions of speakers and amplifiers and I feel that a lot of the time, explanations are simplified so much that they aren't very useful. Which is why you can see my first post in this thread in various versions all over TB.

Thank you very much...and I apologize as well - for a lot. Sorry about the "c" - for some reason the two "c's" in your last name kept throwing me.

I will never claim to have your (or Bill F., or Richard's, or any number of other builders/designers here) sheer technical knowledge of this stuff. I fly aircraft for the military - I don't design speakers. I do, however, do sound for quite a few people here as well as play bass...so I just wanted to be smart (or safe) about the way I purchased gear, etc. Sorry about any oversimplification - it wasn't intended to confuse.

Anyway - have a super weekend! I've got 4 (count 'em 4) shows to do! 2 down and 2 to go....I'm already tired...

Jay

 

[Munjibunga]

No one ever said that they can't hurt your speakers, rather that in some situations they won't and in some situations they will.
The whole 'clipping destroys speakers' thing is far too simplistic to be useful in the real world.

OK, good!

 

[Bassman62]

We're really not that far apart. Though I will still maintain that the vast majority of cone speaker failures are excursion related. D

But surely that is what happens when an amp signal starts clipping. it causes iregular excessive cone excursion often making the speaker bottom out.
The main reasom that high wattage speakers are around is to allow high wattage amplifers to play through them, this in turn produces good quality high level signals instead of overdriven, speaker damaging, clipped signals!