Quick Clip: How to calculate how much amplifier power I need for my speakers? (Tech Talk Episode 57)

A 70v audio amplifier will take an audio signal and turn it into a wattage like an electrical signal which will then drive your speakers. 70 Volt technology allows us to take multiple speakers and run one individual line at a fixed wattage and a constant voltage from one amplifier.

How do you calculate the needed amplifier power for your speakers?

This is a fairly simple math equation. You want to add up your total 70 Volt speakers with their desired wattage tap settings and then ensure that number is not more than the amplifier is capable of producing.
- If you have two 25 watt speakers, 25 watts + 25 watts = 50 Watts + 20% headroom. 20% of 50 is 10 watts. 50 watts + 10 watts = 60 watts. So you’ll require at least a 60 Watt amplifier
- With a 240 Watt amplifier, you can do up to 8 of the same speakers. 8 speakers x 25 watts each = 200 Watts. That leaves a little headroom to play with underneath the 240 Watt max output.

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[m.j.s.]

Thanks—you help with my Hypex Fusionamp 3-way project, an active ‘impersonation’ of the Qualio IQ speakers. You answered the question, re: if one of the amps’ 125w modules was enough for the 4ohm 90w woofer I already bought; with 40% headroom, no problemo. (my ‘Fusionamp 123’ has two, bridgable, Ncore, 125w amps and one 100w amp.)

[rdplanetimmigrant]

i mostly rely on the noise complaints from across state lines.
2 each L & R Electro-Voice ELX200-15P 15 inch Powered Speaker.
stacked on 2 each Behringer B1800Ds in center channel mode.
BEHRINGER FBQ3102 equalizer
Yamaha MG10XU
PC using USB input on mixer. no ground hum.
DENON CD player DN-300C MKII

[jamesnordfors]

I have 2 10 inch speakers with an amp all in one box. I’m not sure if the amp in the speaker box works but I have them hooked up to a 2800 watt amp and going to downgrade to a lower wattage amp soon but not sure what watt amp I should get. Any suggestions would be great 👍

[pradeepjangir]

Hi

I need your support for decide PA speker which we can connect directly to Tinker board 3n speaker header (inbuilt amplifier output of 4ohm 3 watt on each (L+R)).
Please advice speaker rating (ohm & w)
Also cable size with 5 meter

[Spectrvm____]

Watched this video a few times but for my sanity, if you could help me answer this question I would be most grateful! So I have some speakers that say they have a recommended amp power of 40-180 watts. I have a 100 watt amp and it works fine, but if I were to get the next model up which is 200 watts, would the 200 watt amp not only give me headroom but also result in a better quality sound? I’m not too fussed on loudness I’m just on a quest to get more detail out of my music and feel like I’d get that with a more powerful amp. Would appreciate the help!

[peteryousef]

Please we need a video about line array system active speaker. Really I didn't find any good video about it . I need to know the important details about it? How to calculate the max box I can connect in sub like this details if possible?

[stealth_grizz_]

Should a 3k brutus highfonics be okay on an sdr 15 1500 watt??

[mako]

Hello assuming this works for car audio as well, I want prv speakers 6.5 inches that have a 150 rms, 300 program power and 600 peak watts which number do I use to do this calculation?

[samisaac]

I thought is the ohms that determines the number of speakers to connect to an amplifier as you said in one of your video. Please clarify.

[ElowenFaye]

Hello, thank you so much for providing these information!!! May I ask you: I want to buy an amplifier (Fender Mustang 70 W) and I have two speakers (each 50 W). So doing the maths is: 50 W + 50 W = 100 W. + 20% headroom = 120 W. --> Is my conclusion correct that the 70 W amp is not powerful enough? I'd be grateful for an answer! Thank you in advance! :) Edit: I was even considering buying the Fender Mustang 20 W.... This is not a good idea, right? These technical considerations are quite overwhelming since I'm new to all of this. But I'm learning :)

[captainnuggie]

I have a few questions:

I have an old bass combo amp who's speaker just burnt up after I cranked it obscenely loudly, I plan on swapping a 100w celestion guitar speaker into it, but the amp portion of the combo is rated for 75w, will a 100w speaker be powerful enough to handle the 75w amp if I play at bedroom volume?

If it is able to handle the power at lower volumes, will I never be able to crank it high?

Should I have bought a 150w instead?


Thanks

[bowman]

are we not considering the impedance (ohms)?

[Deucenheimer]

I have two Electro-Voice ZLX 12BT (Peak at 1000 watts per) and I wasn't sure how to calculate how many amps of power I would need from an extension cord or how to calculate or understand why a 15A surge protector at 120 volts is enough to power these even though that "Wattage" is 1800... My terms are probably out of wack but any help on my understanding would be greatly appreciated.

[thetruth]

So 2 12s that reccomend 300 to 600 max would be 1200 plus 10% so 1320....so send 1500 watts and turn it down a little?

[john.wick]

Im pretty sure this isn't how it works. Adding more speakers doesn't increase the watt output of your amplifier