Speaker - amp wattage relationship

[bluishbob]

Hi all,
Been talking to people about the realtionship between speaker wattage and amplifier wattage.

At first i thought that you matched your amplifier with the RMS wattage of the speaker at the same ohmage.

However two people have told me that this is actually underpowering the speaker. They have both said that you have to match it to the program power, or in the case of mid/top frequency up to 2x the RMS, Bass up to 3x a and top end 1.5x the rms. and i have also been told that there is more danger of damaging your speakers through underpowering than overpowering.

What are your thoughts? What is the realationship between your amp and speaker wattage?

[Thames Valley Discos]

ideally you want an amp that has power double that of the speakers rms.
i did post some info here at one point with the info you need.

[BeerFunk]

This is an old chestnut, but what amazes me is how no-one seems to know the answers! There are plenty of professionals on these forums, but just watch the variation in answers! :D

Personally, I don't really know, but I do know that you are less likely to blow a speaker with an amp equal to, or with a smaller power rating than the speaker.

[Thames Valley Discos]

well QSC say double RMS, they make the amp so i trust them.

[Excalibur]

This is an old chestnut, but what amazes me is how no-one seems to know the answers! There are plenty of professionals on these forums, but just watch the variation in answers! :D

Personally, I don't really know, but I do know that you are less likely to blow a speaker with an amp equal to, or with a smaller power rating than the speaker.

It is indeed an old chestnut, guaranteed to generate loads of wildly differing views. I run some speakers with one lower rated amp, one equal, and one higher, at different times. If you don't redline any of them, keep the signal green, and don't feed 50w speakers with 500w amps ( and vice versa) then the argument shoulkd be academic. The most effective way of blowing speakers is to overdrive your amp past it's limits.

[Paul James Promotions]

For live music, it should be double. For Disco, anything over the RMS rating of the speaker will be ok, but ideally 50% more and don't let the amp clip at all.

[Tom]

well QSC say double RMS, they make the amp so i trust them.

and the price tag to go with it

[spin mobile disco]

I asked peavey this question and also mackie and they both said double the rms value and dont allow clipping for the maximum output. I use a 500 watt rms per side amp to power a 300 watt rms speaker each side. This gives me significant headroom and has been good for me.

[discomobiledj]

So, I have a 600w amplifier, does that mean I can run 2 x 300w speakers, or 2 x 600w speakers??

[Solitaire Events Ltd]

Either, but you'd be better off having a little head room. The 600w amp would drive the 600w speakers properly.

[Thames Valley Discos]

Either, but you'd be better off having a little head room. The 600w amp would drive the 600w speakers properly.

don't you mean the 300w speakers?
600W amp into 600W rms speakers , i can see clipping issues here

[discomobiledj]

It's only that I have been offered a Biema 600w amplifier and 2 x 600w speakers for £170.00. Obviously I don't want to get them and then blow the speakers/amp on the 1st use!

[Solitaire Events Ltd]

Either, but you'd be better off having a little head room. The 600w amp would drive the 600w speakers properly.


don't you mean the 300w speakers?
600W amp into 600W rms speakers , i can see clipping issues here

I missed a letter or two out - it was supposed to say "The 600w amp wouldn't drive the 600w speakers properly":o

[Sapphire Disco]

So, I have a 600w amplifier, does that mean I can run 2 x 300w speakers, or 2 x 600w speakers??

The way I read your post is your amp is 600w that is probably @ 4ohm which probably makes it approx 400w ie 200w per side @8ohms , so my answer is no it's not enough to run 2x 300w 8ohm speakers , ideally you should be using approx 1000w amp which comes down to no more than approx 350w per side @8ohms

Don't forget most amps power is rated @ 4ohms & most speakers are 8ohm.
so unless you are using 2 speakers each side you do need a higher power amp.
There are many different opinions on this but I have always found it best to have your amp 2/3rds max and master gain not on full so you don't go into red on your mixer and don't clip on amp either.

[nigelwright7557]

I always run speakers at twice the rating of the power amp.

I worked at an audio repeair shop for a while and replaced dozens of speakers blown by wrongly matched amps and speakers !

[colint]

I always run speakers at twice the rating of the power amp.

I worked at an audio repeair shop for a while and replaced dozens of speakers blown by wrongly matched amps and speakers !

Nigel I'm glad you had plenty of work there!

Just for the record I was head of installation at JW Parker sound systems in the old kent road (London from 1970 to 1996 (when mr Parker decided he'd had enough) and to refresh another thread with a simular post you should always use an amplifier with at least 20% more power than your speakers are rated at so the signal dosen't distort!

a distorted signal will damage drivers faster (especialy compression drivers) faster than you can blink and that is a proven fact! :)

[Tom]

or buy active. :lol:

problem solved

[colint]

Tom, what would you do when your amp goes west on your active speakers!

speaker systems should be made from the best birch ply (not plastic) and have nothing else but the drivers & a crossover in them, oh! what a perfect world it would be!!!!!!!

[Tom]

what do you mean "amp goes wast on your active speakers"

[colint]

west! not wast! I havn't had that much Jamesons (yet)

what happens half way through anuty mable's 50th when you amp goes on your active speaker? what'll you do then fit another amp in the cab?

[Corabar Steve]

Have you never heard the term gone west? You know, up the swanee, kaput, etc...

[nigelwright7557]

"well QSC say double RMS, they make the amp so i trust them."

Yes the speakers should be double the amp output.
If they said the other way around then they are just looking for business !!!

[Solitaire Events Ltd]

"well QSC say double RMS, they make the amp so i trust them."

Yes the speakers should be double the amp output.
If they said the other way around then they are just looking for business !!!

Sorry, I disagree and so do a lot of other users.

[nigelwright7557]

But your not a fully qualified electroncis engineer with 30 years experince !

Plus been a dJ for 32 years.

Plus worked in an audio repeair shop and replaced dozens of speakers blown up by amps that were too powerful.

I rest my case.

[Solitaire Events Ltd]

But your not a fully qualified electroncis engineer with 30 years experince !

Plus been a dJ for 32 years.

Plus worked in an audio repeair shop and replaced dozens of speakers blown up by amps that were too powerful.

I rest my case.

And how would you know any of this?


There are lots of people on here with years of experience, so don't discount people because you think you have the most experience and are always right.

[Excalibur]

"well QSC say double RMS, they make the amp so i trust them."

Yes the speakers should be double the amp output.
If they said the other way around then they are just looking for business !!!

There are a lot of folk, Peavey, for one saying this. ( amp double output of speakers) I don't necessarily agree totally, but there appears to be no black and white correct answer to this.

[nigelwright7557]

If a speaker has 100 watts written on it and it tales 200 watts then it is really a 200 watt speaker.

Also the wattage depends on the ambient temperature so in a hot room it should be downgraded.

If you are running a 100 watt speaker at 100 watts then transients can go way over 100 watts causing distortion.

Some manufacturers tend to cut corners too and the speakers will fail at little above their rating.

Believe me I have made a fortune out of blown up speakers.

[Solitaire Events Ltd]

There are a lot of folk, Peavey, for one saying this. I don't necessarily agree totally, but there appears to be no black and white correct answer to this.

Agreed.

[Excalibur]

If a speaker has 100 watts written on it and it tales 200 watts then it is really a 200 watt speaker.

Also the wattage depends on the ambient temperature so in a hot room it should be downgraded.

If you are running a 100 watt speaker at 100 watts then transients can go way over 100 watts causing distortion.

Some manufacturers tend to cut corners too and the speakers will fail at little above their rating.

Believe me I have made a fortune out of blown up speakers.

And some speakers have 400watts written thereupon, and are barely 100!:bang:

[nigelwright7557]

I agree completely.

The same goes for amps.

I was silly enough to buy a cheap one off ebay that was supposed 480 watts.
I tested it and it was 50 watts RMS per channel or 200 watts peak all in.

The 480 was a complete lie.

In this case this 480 watt amp would have blown up a 50 watt RMS speaker

[colint]

I'd still rather have a second hand peavey cs800 than a new prosound/behringer/other cheap amp and the peaveys can be got for as little as £100 on fleabay! total bargin!!!!

Edit: bit like this:

http://cgi.ebay.co.uk/Peavey-CS800X-Professional-Amplifier-DJ-Equipment_W0QQitemZ170161574922QQihZ007QQcategoryZ 69962QQssPageNameZWDVWQQrdZ1QQcmdZViewItem

[gillo]

Hi all,
Been talking to people about the realtionship between speaker wattage and amplifier wattage.

At first i thought that you matched your amplifier with the RMS wattage of the speaker at the same ohmage.

However two people have told me that this is actually underpowering the speaker. They have both said that you have to match it to the program power, or in the case of mid/top frequency up to 2x the RMS, Bass up to 3x a and top end 1.5x the rms. and i have also been told that there is more danger of damaging your speakers through underpowering than overpowering.

What are your thoughts? What is the realationship between your amp and speaker wattage?

general disco work 1x - 2 x rms of speakers live work at least 2 x rms of speakers as live audio often has peaks in the signal causing amps to clip severly without you knowing often causing compression driver to blow instantly!

[nigelwright7557]

I'd still rather have a second hand peavey cs800 than a new prosound/behringer/other cheap amp and the peaveys can be got for as little as £100 on fleabay! total bargin!!!!

Edit: bit like this:

http://cgi.ebay.co.uk/Peavey-CS800X-Professional-Amplifier-DJ-Equipment_W0QQitemZ170161574922QQihZ007QQcategoryZ 69962QQssPageNameZWDVWQQrdZ1QQcmdZViewItem

I have been stung on ebay a few times with old equipment.
The "only used once" "never gigged" claims are lies, most times it has been flogged to death and further. I have had to send a couple of pieces back coz they were only good enough for the bin.

Even the new amps on ebay dont match the wattage claims.


general disco work 1x - 2 x rms of speakers live work at least 2 x rms of speakers as live audio often has peaks in the signal causing amps to clip severly without you knowing often causing compression driver to blow instantly!

I really cant agree with this.
I always run the speakers at trwice the wattage of the amp.
If yo urun the otehr way around for a any long period the speakers will overload, melt the insulation on the voice coil and short out the amp.

[Corabar Entertainment]

I have been stung on ebay a few times with old equipment.
The "only used once" "never gigged" claims are lies, most times it has been flogged to death and further. I have had to send a couple of pieces back coz they were only good enough for the bin.

Even the new amps on ebay dont match the wattage claims.I don't think you can really make sweeping claims like that: ie that all sellers of both new and 2nd hand equipment on ebay are liars!

You really need to THINK a bit before you post Nigel! :mad:

[nigelwright7557]

I don't think you can really make sweeping claims like that: ie that all sellers of both new and 2nd hand equipment on ebay are liars!

You really need to THINK a bit before you post Nigel! :mad:

You need to think a bit too.

I never said that, I simply relayed my experience on ebay.
:bang:

[colint]

I have been stung on ebay a few times with old equipment.
The "only used once" "never gigged" claims are lies, most times it has been flogged to death and further. I have had to send a couple of pieces back coz they were only good enough for the bin.

Even the new amps on ebay dont match the wattage claims.


I really cant agree with this.
I always run the speakers at trwice the wattage of the amp.
If yo urun the otehr way around for a any long period the speakers will overload, melt the insulation on the voice coil and short out the amp.

Close to slander I think! I'd be really careful making statements like that if I were you!

[Corabar Entertainment]

That IS NOT what your post says.

Your post stated that you've been stung a few times, but then went on to say

The "only used once" "never gigged" claims are liesand
Even the new amps on ebay dont match the wattage claims.Both of which are sweeping statements and can be seen to be libelous. I know you intended to refer only to your experiences, but that is not what you have done. Hence my asking you to think before you post.

Now please put a bit of thought into your posts, and if a mod, admin, or owner asks you to watch out for something, we do it for a reason.

[nigelwright7557]

That IS NOT what your post says.

Your post stated that you've been stung a few times, but then went on to say
andBoth of which are sweeping statements and can be seen to be libelous. I know you intended to refer only to your experiences, but that is not what you have done. Hence my asking you to think before you post.

Now please put a bit of thought into your posts, and if a mod, admin, or owner asks you to watch out for something, we do it for a reason.

Not libelous if they are true !
And they are.

[colint]

Oh dear!

[BeerFunk]

Not libelous if they are true !
And they are.
They may well be true in the sellers that you have dealt with, but you can't assume they're all like that?

[gillo]

I have been stung on ebay a few times with old equipment.
The "only used once" "never gigged" claims are lies, most times it has been flogged to death and further. I have had to send a couple of pieces back coz they were only good enough for the bin.

Even the new amps on ebay dont match the wattage claims.



I really cant agree with this.
I always run the speakers at trwice the wattage of the amp.
If yo urun the otehr way around for a any long period the speakers will overload, melt the insulation on the voice coil and short out the amp.

ok then you carry on using your equipment like this, seeing as your always correct! i am in contact with one of the designers of void acoustics one of the best researched and designed audio equipment ever made! top manufacturers like these quote this rule so if there doing huge installs and tours then i take these guys are wrong aswell? if you have got a loudspeaker that is rated at 500 watts rms and you supply it with 250 rms thats all you will ever get out of it if your lucky that nothing burns out. a rule of thumb to even get 250 watts rms out of the speaker the amp and everything else will be on full! explain how nothing is not going to burn out?

[nigelwright7557]

They may well be true in the sellers that you have dealt with, but you can't assume they're all like that?

I am sure not all sellers are bad.

But I would no longer buy second hand off ebay.
I am wary of buying new gear at times off ebay.

Thats why I prefer to design and build my own.
I know my own gear is up to the job and then some.

[Corabar Entertainment]

Fine and fair enough, but your original post was SWEEPING and LIBELOUS - hence my comments.... so your reaction? To argue and post it again! Not on, I'm afraid (oh and also a breach of the forum rules)

[nigelwright7557]

I am simply warning unsuspecting DJ's about junk being sold on ebay.

For those who dont build their own gear I would suggest paying a decent amount of money and buying decent stuff.

[colint]

I am simply warning unsuspecting DJ's about junk being sold on ebay.

Thanks for that! I sell a lot of stuff on ebay and other sites including dj bids so does that mean I'm selling junk too?

[Tom]

just to note that not all of us can afford expensive equipment.

[rob1963]

just to note that not all of us can afford expensive equipment.

...and not all of us WANT expensive equipment!

[Tom]

point made.

its not about how much you spend on a speaker for example. Its how you use and what suits your needs.

[rob1963]

I am simply warning unsuspecting DJ's about junk being sold on ebay.

Firstly, junk is sold in plenty of other places.

Secondly, I've purchased 130 items on ebay, all offering excellent value for money, but none of which I would describe as junk.

[gillo]

point made.

its not about how much you spend on a speaker for example. Its how you use and what suits your needs.

judging by the sound of it he doesnt know how to use any equipment efficiently and properly.

[Tom]

im not saying anything. :zip:

maby is he used the search bar and had a look on other posts. i have learned this way and posting a few threads myself about speaker and amps if im correct. iv learned from it....

[gillo]

im not saying anything. :zip:

maby is he used the search bar and had a look on other posts. i have learned this way and posting a few threads myself about speaker and amps if im correct. iv learned from it....

totally agreed! i have benefited alot from this forum and gained so much knowledge! its untrue! i just do not like people wading in thinking they no everything and when they have an opinion against them they cant take it and take it one step to far!:D

[Solitaire Events Ltd]

Firstly, junk is sold in plenty of other places.

Secondly, I've purchased 130 items on ebay, all offering excellent value for money, but none of which I would describe as junk.

I dunno, I've seen pictures of your show...:boxer2: :D


totally agreed! i have benefited alot from this forum and gained so much knowledge! its untrue! i just do not like people wading in thinking they no everything and when they have an opinion against them they cant take it and take it one step to far!:D

Here here. :)

[rob1963]

I dunno, I've seen pictures of your show...:boxer2: :D

:eek: :boxer2: :moon: