Is it OK for Speaker wattage to be higher than my amp wattage

[Monoprice99]

Everything I read says that speaker wattage should be the same or lower so the amp doesn't get damaged.

You got that backwards you don't want to blow speakers and have no load on a tube amp head or chassis in a combo. Solid State is the one everyone says it's relatively safer to have no load from an accident. Having more speaker than the amp pumps out RMS or peak and the amp should be fine, because that's what it's supposed to do when the impedances are matched or safe matched. A RC 75W speaker is inexpensive in comparison to a tube amp, it would be a shame to damage a tube amp's power transformer & perhaps something else because the speaker couldn't handle the wattage RMS or peak. Which is easier & less expensive to troubleshoot or replace ? The amp head/guts or a single driver in a combo practice amp ? I mean, I wouldn't want to replace any of it, but if I have a choice, I can swap a speaker a lot easier than a power transformer. I think if a 25W Frontman is blowing a 75W RC speaker, there's something else going on inside the amp that is seriously wrong with the amp or even speaker.

The other question is a series vs parallel wiring among multi-speaker cabinets. A Frontman 25 is a single speaker combo, not 2 speakers. Whatever the speaker's impedance is, that's what needs to be safely matched with the amp's output impedance.

As I understand it from reads, you do want o ensure the speaker leads are matched as "+" & "-", the speaker would then be out of phase.

https://www.techwalla.com/articles/what-happens-if-i-reverse-my-speaker-wires

 

[Leonardocoate]

Well then, there's irrefutable proof! Go ahead and take your advice from BOOM! Speaker.com. But you might have a hard time finding a guitar speaker that's half the wattage of your Frontman 25, if that's meant to be its wattage. According to BOOM! Speaker.com you & your amp are in mortal danger. Good luck, and don't forget your personal protection. Better go to the counter at GC and tell the guys you need 25-watt rated safety glasses.

For the record I agree with what everyone here is saying on this thread. (I have never seen a 12.5 watt speaker). I am however trying to make sense of the many articles that say the exact opposite. I thought maybe I formed some sort of dyslexia.

 

[JIMMY JAZZMAN]

Times 2 is good. 30 watt speaker 15 watt amp. Sometimes times 3 is better. Depends on the tonal
capabilities and different extras (reverb, tremolo, gain) the amp has. Even pedals could increase it
to times 4. You'll know, right away.

 

[Leonardocoate]

your speaker should be rated at twice what the amp puts out, so as not to overpower the speaker. so your 75w ragin cajun is fine taking the 25w.
that whole series/parallel thing changes impedance values, not wattage. if you run two 8 ohm speakers in parallel, the total load becomes 4 ohms. wire them in series and the total load becomes 16 ohms. anyway, leave the cajun in there - it sounds like it's happy where it is.

This is the logic that I have always subscribed to, and will continue to. I am also happy where it is.

 

[Swirling Snow]

FULL STOP!!!

Shame on you guys, you should know this by now.


For PA, studios, and Hifi, you want so much power you'll never distort the amp. Distorted signals cause heat in the voice coil and amps are (relatively) cheap.

For guitars, the amp is supposed to distort, so guitar speakers have huge gaps in the voice coil for cooling, but you still should over-rate the speaker wattage 2 to 3 times and four speakers is better than one for cooling.

 

[King Fan]

Moral of the story? Never read the hifi, guys, not wise, all lies…

 

[Happy Enchilada]

I've always heard your speaker needs to be rated higher than your amp output so as not to blow a speaker. Those of us who occasionally turn up to enjoy some OD and solo work don't want to destroy our beloved amplifiers in the process.

I have a 50 Watt Quilter Reverb 101 that I run through a 1x12 cabinet with an Eminence Red White & Blues speaker rated @ 120 Watts. It sounds great and seems to be a happy rig.

 

[PhredE]

I don’t mean to hijack the thread, but whilst we’ve got smarter people than me on here talking about power ratings, I always wondered, if you have an 100w amp that requires an 8 ohm speaker; if you attach 2 speakers that are 16 ohms (so 8 ohms total), do those speakers need to be both rated at 100w, or would 2x 50w speakers be OK? Seems like amps with variable impedance say things like “200w 4 ohms, 100w 8 ohms, 50w 16 ohms” on the back, which got me wondering…

'Attach' could be implemented as either a serial or parallel wiring. If parallel, yes the total load the amp 'sees' is right about 8 ohms. If serial, the impedances are additive, so the amp 'sees' about a 32 ohm load approx. Impedance ratings and power handling estimates don't depend upon one another really.
Short answer is : yes, 2x50w (16 ohm) speakers wired in parallel should work ok when the amp 'expects' to see 1 100w 8 ohm speaker.

In the case of many tube amps, the variable power and impedance ratings are accommodated by multiple taps from the output transformer. Many were built around the idea different speaker types/cabinets might get used later. Most older analog SS configurations don't incorporate multiple taps from OT -- so, many are less flexible in terms of speaker output flexibility. If it says '8ohm speaker only', it's good to stick to 8 (or whatever the amps says it 'expects').

Many newer Class D based SS designs can easily accommodate variable impedance output loads (say, 4-16 ohms without a worry). Of course, the penalty of using a higher impedance speaker is less output power. Example: at 4 ohms an amp might produce 45WRMS, at 8 ohms produces 33WRMS and at 16ohms 17WRMS, etc.

A low impedance speaker allows more power output and that *can* be a way to tweak out a bit more volume too. A higher impedance will 'sap' output power. Some, newer Class D amps have total load protection built in. So, I can yank the speaker cable from the amp and not worry that the amp will fry (very nice, because I've done that more times than I care to admit to!), or, I can run the amp with controls dialed up and use no speaker at all (just headphones, direct out, etc) and not worry about trashing the amp.


Speaker sensitivity and being able to interpret a response graph are other aspects that don't get emphasized enough IMHO. Many guitar amps are typically designed around the idea that a high efficiency speaker be paired with a relatively low powered amp (a Princeton is only 12-15 watts I'd humbly remind, and a Twin is about 85). If the speaker is efficient, it doesn't 'need' to use a lot of power. An efficient speaker can take the relatively small amount of output power and make it loud enough to use in most settings.

There are some of us that use sort of an inverted approach and use a more powerful amp paired with relatively inefficient speakers with high power ratings. I know I'm not typical of this approach, but it guarantees that the speaker will handle any amount of power thrown at it, and never break up ( I don't like doing the speaker purchase lottery -- once I find something that I like, I stick with it). Big robust speakers (big magnets with a solid construction) generally will never flub out on low notes too.

 

[Leonardocoate]

I don’t mean to hijack the thread, but whilst we’ve got smarter people than me on here talking about power ratings, I always wondered, if you have an 100w amp that requires an 8 ohm speaker; if you attach 2 speakers that are 16 ohms (so 8 ohms total), do those speakers need to be both rated at 100w, or would 2x 50w speakers be OK? Seems like amps with variable impedance say things like “200w 4 ohms, 100w 8 ohms, 50w 16 ohms” on the back, which got me wondering…

My understanding is that your speaker wattage is always constant, but the resistance can be divided or doubled which would change the power delivery. As long as there is a desirable sound coming out you are good to go

 

[andy__d]

Thanks very much for the explanation PhredE and Leonardocoate, that makes sense now.

 

[PhredE]

speaker wattage is always constant, but the resistance can be divided or doubled which would change the power delivery.

'Wattage' is the amount of power the speaker will handle before experience physical damage.

'Resistance' (related to impedance, but are not the same thing!) -- impedance is probably what you might be thinking of I am guessing. Impedance is dynamic and changes in relation to the audio signal at a particular frequency.

Here's a link to an Eminence speaker (Beta 8a)

BETA-8A 8

Recommended for professional audio mid-bass applications or as a woofer in vented enclosures. Also suitable as a mid-bass speaker in sealed enclosures.

eminence.com

The dark line is the output response (db) as a function of frequency. The lighter line is impedance as a function of frequency. It's not a flat constant amount -- it varies by frequency, and can range down to the low (where they are usually nominally rated) all the way up to, say, 80 or 90 ohms at times.

 

[JustABluesGuy]

Here are three links that say the amp rating should be higher than the speaker. Maybe these are pro audio examples, but the science should be the same

Speaker Wattage Vs Amp Wattage - BoomSpeaker

When considering speaker and amplifier power, people often try to match the power requirements of both devices. Others simply ensure that the amplifier wattage is higher than the speaker wattage. There is a lot of wrong advice on the internet about this. We will clear it up today. What is the...

boomspeaker.com

Should Speaker Wattage Be Higher Than Amp Wattage?

If you're looking for outstanding sound quality and power in your sound set, here's how to match the wattage of your speakers to your amplifier.

www.audioreputation.com

Matching Speakers With Amps As Far As Wattage? - inSync

From inSync reader David R. comes the following e-mail: "Is there a rule of thumb for... Read more »

www.sweetwater.com

These seem to be talking about hi fi audio. Guitar amps and high end audio “work” differently and have different goals in mind.

With a hifi system low distortion is the goal because you want to faithfully reproduce prerecored music. With guitar amp, people are often wanting (even adding) distortion to the signal. It is the distortion that hifi speakers don’t like.

Guitar player tend to like distortion, but don’t want to blow speakers to get it.

Hifi and guitar amps while similar have diverged over time. Don’t go by audiophile sites for guitar amp info. I had to relearn a few things myself since I came from the high end audio world.

 

[schmee]

It's good as a general rule to have the speaker wattage about 1.5 to 2X the amp wattage.

This rule has been broken many times though, even by Fender.
Higher speaker wattage rating often results in better low end also.

 

[printer2]

What no one has mentioned yet is the different wattage ratings in a hifi speaker. It is pretty rare to have a single driver to do the full range of the frequency spectrum, we normally use a woofer and a tweeter at a minimum. And the tweeter needing to be low mass it has a power rating of a few watts at most. Thankfully we do not listen to music with a great deal of high frequency energy so all is good. Until you overdrive the amp and the clipping puts more high frequency energy into the tweeter and melting the voice coil. So in hifi it is best to have more power than needed in order to keep the distortion (amp created high frequency energy) out of the tweeter. There is talk about woofers being damaged by square waves, I am not too sure of that. It could be that a clipped 100W amp can put out 200W of distorted energy. Feeding the same speaker with 200W of clean energy, will it blow? Not sure. But for guitar I tend to go with the 2X wattage rating for speakers.

 

[JustABluesGuy]

Where are you reading that? Speaker wattage should be the same or more than the power output of the amp. A speaker with a rated wattage that's lower than the amp output is likely to fail, and that's likely to damage the amp.

Speaker total wattage and impedance isn't as simple as this doubles that, etc. Wattage adds, impedance needs to be calculated based on individual impedances. There are also strategies that you should employ that take into account a speaker failure, etc. If you want to go down that road at some time it'd be best to post a thread with specifics of what you want to do.

It seems he got the info from audiophile websites talking about stereo equipment.

 

[JustABluesGuy]

For the record I agree with what everyone here is saying on this thread. (I have never seen a 12.5 watt speaker). I am however trying to make sense of the many articles that say the exact opposite. I thought maybe I formed some sort of dyslexia.

High end stereo and guitar amps are different. You just got your info from the wrong source.

If you were buying a stereo system, that advice would be fine. We’re talking about guitar amplifiers, not stereo equipment.

 

[Nicko_Lps]

Everything I read says that speaker wattage should be the same or lower so the amp doesn't get damaged. Does that apply to solid state amps or just tubes.

You must have read info from the people that use 200USD wood stands on speaker cables to improve "tone".

When it comes to TUBE guitar amps, you want almost double watt rating on your speakers.

A guitar amp is rated by Marshall as "100 watt" produces 100 watt CLEAN, as you push the master and distortion increases it can output almost double.

Here is a Marshall user manual, look at the ratings and MAX output:

When it comes to home audio....
If you buy those amps who weigh 300grams and claim to be 400watt x 2, yeah you can use lower wattage speaker because that thing is nowhere near its rating.

My 1978 made Beomaster 2400-2 is 7.6 kilos and its 2x75watt, when it comes to this i can use 75 watt speakers because it will not distort more than 0.2%


My tube amp is 40 watts, in to distortion and pushed with a pedal could output twice as much. So i use a 100watt cab and im perfectly safe

 

[Leonardocoate]

High end stereo and amp a very different. You just got your info from the wrong source.

If you were buying a stereo system, that advice would be fine. We’re talking about guitar amplifiers, not stereo equipment.

I realize that now. The first article I read referred to guitar amps (It was wrong) which which took me down a rabbit hole of stereo equipment which made me question what I know. I'm breathing normal again.

 

[JustABluesGuy]

Quit reading that hi-fi crap - the writers are suspect, they often live in imaginary worlds and are suckers for pseudo-science & expensive geegaws...and that "technology" has nothing to do with guitar amplification anyway. About as much in common as cooking & welding.

The advice he got is good, but only for stereo systems, not for guitar amps. I had to relearn some things myself since I started out in the audiophile world.

They are just different worlds with different inherent goals. They don’t overlap much, so the “good advice” for the two differs.

 

[JustABluesGuy]

'Attach' could be implemented as either a serial or parallel wiring. If parallel, yes the total load the amp 'sees' is right about 8 ohms. If serial, the impedances are additive, so the amp 'sees' about a 32 ohm load approx. Impedance ratings and power handling estimates don't depend upon one another really.
Short answer is : yes, 2x50w (16 ohm) speakers wired in parallel should work ok when the amp 'expects' to see 1 100w 8 ohm speaker.

In the case of many tube amps, the variable power and impedance ratings are accommodated by multiple taps from the output transformer. Many were built around the idea different speaker types/cabinets might get used later. Most older analog SS configurations don't incorporate multiple taps from OT -- so, many are less flexible in terms of speaker output flexibility. If it says '8ohm speaker only', it's good to stick to 8 (or whatever the amps says it 'expects').

Many newer Class D based SS designs can easily accommodate variable impedance output loads (say, 4-16 ohms without a worry). Of course, the penalty of using a higher impedance speaker is less output power. Example: at 4 ohms an amp might produce 45WRMS, at 8 ohms produces 33WRMS and at 16ohms 17WRMS, etc.

A low impedance speaker allows more power output and that *can* be a way to tweak out a bit more volume too. A higher impedance will 'sap' output power. Some, newer Class D amps have total load protection built in. So, I can yank the speaker cable from the amp and not worry that the amp will fry (very nice, because I've done that more times than I care to admit to!), or, I can run the amp with controls dialed up and use no speaker at all (just headphones, direct out, etc) and not worry about trashing the amp.


Speaker sensitivity and being able to interpret a response graph are other aspects that don't get emphasized enough IMHO. Many guitar amps are typically designed around the idea that a high efficiency speaker be paired with a relatively low powered amp (a Princeton is only 12-15 watts I'd humbly remind, and a Twin is about 85). If the speaker is efficient, it doesn't 'need' to use a lot of power. An efficient speaker can take the relatively small amount of output power and make it loud enough to use in most settings.

There are some of us that use sort of an inverted approach and use a more powerful amp paired with relatively inefficient speakers with high power ratings. I know I'm not typical of this approach, but it guarantees that the speaker will handle any amount of power thrown at it, and never break up ( I don't like doing the speaker purchase lottery -- once I find something that I like, I stick with it). Big robust speakers (big magnets with a solid construction) generally will never flub out on low notes too.

I often use an Eminence Reignmaker for this very purpose. I adjusts from 92 or 3 dB to over 100 dB. It’s very handy and I also love the sound of it. I don’t know why they weren’t more popular.