Amp wattage vs Speakers

[DetroitBlues]

I’m arguing with a guy about amps with higher wattages using speakers with lower wattage and how it promotes speaker breakup.  He claims they must be at least the same or else you’ll blow up your speakers.  

Help me win this argument!

[JeffB]

I think the terms you are using are wrong.  I dont think you mean wattage. I think you mean db.

Sensitivity and,  stuff.

 

[Steiner]

My Soldano Decatone (100W) has 2 15W alnico blues for a 30W capability.  It's been that way for years.

You can use under power speakers, just don't turn it up too loud or you'll blow them!

[JeffB]

29 minutes ago, Steiner said:

My Soldano Decatone (100W) has 2 15W alnico blues for a 30W capability.  It's been that way for years.

You can use under power speakers, just don't turn it up too loud or you'll blow them!

I used to swap out power amp tubes in one amp regularly between 6L6's (for 60w)and EL84's w/yellow jackets (for 15-18w) and would swap speakers from 100w celestion to a 25w celestion.

Sometimes, a couple of times, I  forgot which speaker or which tubes were in there. I never blew anything up using the GB 25w with the 6L6s but did know that something was going on with my sound or feel of the amp. Basically just panicked for the rest of the night, kept the volume down regardless of what was going on around me and hoped that I didnt destroy the amp before I finished the gig.

A less efficient speaker breaks up before a more efficient speaker. I like speaker break up, a certain type or frequency, so Im inclined to seek out less efficient speakers. I wasnt always like that, I used to love clean clean amps at loud volumes and would look for efficient speakers to keep everything tight and clear, like a spruce top acoustic guitar sound.

 

 

 

[212Mavguy]

@ the OP...

What matters is how many watts you are using to play with and whether you are playing clean or dirty tones.  It's an interesting subject...  

Sometimes a speaker can be blown when using an amp rated for less than the speaker is.  For instance, I had  Hughes & Kettner tube 20.  Was playing in a loud jam situation, I had lent that amp to a friend.  He had the amp cranked up and also had a dirt pedal in the fx loop.  The speaker was a vintage Jensen P12n.  It was a fairly high rated speaker for wattage when compared to their less beefy P12R and P12Q.  It died in about an hour of loud, distorted playing from an amp running a pair of el84's!!!   Got it reconed with a 50w rated VC, put it back in, and I killed it again.  Never did recone that speaker again yet...  The square waves I was pushing through from high volume clipping was the culprit, operator error so to speak.   The stiffness in the suspension was also a factor...All other things being equal, dirty tones are harder on speakers for a given wattage than clean ones are by far.   

One of my friends is a Mesa lover, has a few Mark !! combos.  He used to run EVM12l speakers, now has switched to using a Tone Tubby Nashville ceramic in his favorite Mark II C+ simul-class, a 100 watt 1/12 beast that runs a pair of el34's biased in class A and a pair of 6l6gc biased in class AB.  The tone from the Nashville is tight, punchy, articulate, detailed, plenty of top end that never gets harsh, and very expressive to pick touch like the EVM's are, but the TT's weigh ten pounds or so less per speaker.  He uses a 1/12 Mesa Thiele cab also containing a ceramic Nashville in additon to the combo amp.  I think that the Nashville sounds better than the EV's and he thinks so too.  He plays fairly loud when gigging, and has used that Nashville speaker rated for 75 watts, for a long time gigging out frequently without any problems.  He plays country and uses dirt pedals.  In his case, the speaker handles his tones well, both because he is not using more power at the gig than the speaker is rated for, and also that the speaker is well made, and has a screen dust dome.

I have had great luck with JBL G125 and MI-12 speakers, they are vented and that venting helps the voice coils cool.  The Jensen that got killed twice has no ventilation.  The Altecs I like are sealed, but they employ the metal dust dome both as a way to extend high frequency response, and also as a heat conducting radiator to cool the voice coil.  The material that the vc former is made of has a gread deal of effect on how well the speaker handles heat.  Paper or cardboard voice coil formers do not handle heat as well as Kapton or aluminum formers do.  

So if I am looking for a speaker to handle dirty tones, I like to see some kind of ventilation, either a hole through the magnet or some sort of screen dust cover that allows air movement through it.   

I personally prefer speakers that to not have cone breakup at higher volumes... at all.  I like to hear what the amp and guitar is putting out, clearly and well detailed.  I spend a lot of $$ and time to get that harmonic detail, so I want to hear the selected tone set sounding consistently similar at loud or soft volumes without having to mess with tone knobs.    Recently I switched to using tone Tubbys, and have found that they sound fantastic for what I like to do and are waaaay worth the money spent.  Have a lot of 12 inch Altec and JBL speakers to sell now because of the way that the Tone Tubbys sound.  YMMV.  Hope this helps.

 

 

 

[Kuz]

In short, you are wrong Josh and your friend is correct. 

You should have a speaker (or speakers) that match or exceed the power watt rating of your amp.   For example, a 30 watt amp needs at least a 30 watt speaker.   If you play at very low volume, you may be able to get away with say a 15 watt speaker.  But through a pedal in front and you are pushing more dbs and that speaker could blow.

What you are talking about is using speakers with lower dbs & sensitivity ratings.   A 95db speaker will require you to turn your amp's volume setting up (say 3 or 4) and you will lose clean headroom thus the speaker & amp breaks up quicker at lower volumes than say a 103db speaker which will be very loud & clean at lower amp volume settings (say 1.5 -2).  The decibels coming out of the amp will be the same overall volume (ie 95db speaker at 3-4 or a 103db at 1.5-2) but the lower sensitivity speaker (95db) will cause your amp to break up quicker. 

[bolero]

9 hours ago, DetroitBlues said:

I’m arguing with a guy about amps with higher wattages using speakers with lower wattage and how it promotes speaker breakup.  He claims they must be at least the same or else you’ll blow up your speakers.  

Help me win this argument!

I would be inclined to agree with the other guy, too!

although multiple lower watt speakers will distribute the load. ie 4x 25w greenbacks with a 100w amp

no way would I ever crank up a 35-50w amp with a single 25w speaker

although a sealed cab will help a speaker out a bit...ie 15w celestion blue in a sealed cab would probably be ok with an 18- 20w amp cranked. ( but if you crank it and use a distortion pedal as well, all bets are off! )

 

*edit*

actuslly I think new celestion blues are rated a bit higher than 15w, but you get the idea

 

 

[DetroitBlues]

So why would Fender sell a Supersonic 60 amp with a 30 watt speaker?  Are they looking for warranty repairs?

[kbp810]

You are partially correct, in that a low power speaker will add speaker distortion into the mix, but that's walking a fine line between adding breakup and blowing the voice coil or cone.

Pairing a low watt amp with a low Db speaker would be a better idea - but in this case, you're not necessarily adding speaker breakup, you're just reproducing the sound at a lower decibel level, which means you can crank the amp up into override without it being as loud. Though in my experience... playing a lower powered amp through a lower sensitivity speaker, sometimes produces a somewhat muddy sound.... Playing a high power amp through a low sensitivity speaker at high volume, however, is usually a wonderful thing!

Of course, these are just generalizations - there are other variables involved. There are some speakers designed to add some speaker distortion to the mix... but my preference has always been to use speakers that can handle what you're throwing at them; and let the guitar/amp/effects shape the tone. 

[kbp810]

9 minutes ago, DetroitBlues said:

So why would Fender sell a Supersonic 60 amp with a 30 watt speaker?  Are they looking for warranty repairs?

Because they're jerks! lol - the amp may technically be capable of putting out 60 watts, but that doesn't mean that under load this is what it's putting out (kind of like crank HP and wheel HP). But yes, this is a condition where the amp is over powered for the speaker, and the speaker is likely going to breakup and add speaker distortion into the mix... and yes, if you were to play the amp and guitar dimed out... especially with a high gain effect in the chain... you're likely to kill the speaker. Fender might warranty it at that point... or they'll just point the finger at you and say you were playing it too loud and abused the amp. 

[mars_hall]

Wattage in amps is measured at a fixed frequency (typically 1 kHz) at a stated distortion level (THD).  Move the frequency or stated allowed distortion and the declared power results change accordingly.  It allows a comparison at a single point in characteristics and is not the catch-all being implied.

If the amp has a scooped response curve versus a mid-range dominant one, the overall delivered wattage over the entire spectrum will vary widely, even though they measured identical at the 1 kHz 10% THD point.  The speaker does not react to the single frequency, but those present.

[JeffB]

1 hour ago, DetroitBlues said:

So why would Fender sell a Supersonic 60 amp with a 30 watt speaker?  Are they looking for warranty repairs?

It has a Celestion Vintage 30 which is a 60watt speaker.

[Steiner]

26 minutes ago, JeffB said:

It has a Celestion Vintage 30 which is a 60watt speaker.

Bingo!

[bolero]

man, that is funny!!

[DetroitBlues]

Ah, so my 2x12 with V30's is actually 120 watts, not 60's.  Good to know!

[ElNumero]

On ‎4‎/‎2‎/‎2018 at 11:21 AM, DetroitBlues said:

So why would Fender sell a Supersonic 60 amp with a 30 watt speaker?  Are they looking for warranty repairs?

Let me dime my Supersonic 60 later on today and I will let you know how the speakers take it as well as how the neighbors react.

[DetroitBlues]

On 4/3/2018 at 12:03 PM, ElNumero said:

Let me dime my Supersonic 60 later on today and I will let you know how the speakers take it as well as how the neighbors react.

Well did the police show up asking where the party is or are you unable to lift it out of the back of the closet?

[Yooper]