Audio amplifier

Thread Starter

nikolopikolo

Joined Sep 17, 2020
9
Hello,

I have decided to build my own loud speaker from scratch. That means tha I will be building my own power amplifier. Now I want it to go as loud as it can so about 500W RMS should do it. I want to know are there any sites with schematis of such amplifier and I want a qulity one not something thrown together by some ameteur. Also if you got any advice for me about the topic feel free to let me know.

Nik
 

Papabravo

Joined Feb 24, 2006
14,684
Hello,

I have decided to build my own loud speaker from scratch. That means tha I will be building my own power amplifier. Now I want it to go as loud as it can so about 500W RMS should do it. I want to know are there any sites with schematis of such amplifier and I want a qulity one not something thrown together by some ameteur. Also if you got any advice for me about the topic feel free to let me know.

Nik
I suspect the answer to your question is no. Although there are numerous sites with schematics, there are very few places to find a critical analysis of those schematics. So you are left with the task of evaluating alternatives with the resources you have at hand. As an amateur astronomer I'm going to give you some advice which you can take or not as the mood moves you:

If you want to make an 8 foot diameter mirror for a telescope you can reach that goal faster, by first building a series of smaller mirrors of 1', 2', and 4' in diameter.

I leave it to you to understand the meaning and wisdom of that statement.

Note carefully the warnings on the Elliott 500 W subwooffer amp and relate them to the italicized statement above.
 

Ian0

Joined Aug 7, 2020
750
I hope this is to be used outside or in a concert hall. 50W is more than enough to blow out your eardrums in a normal home.

Bob
Maybe - that depends on the efficiency, and that can vary over 3 orders of magnitude, from about 80dB@1W@1m for small subwoofers to 115dB@1W@1m for large horn-loaded designs.

A 500W amplifier driving an 80dB@1W@1m speaker, makes the same noise as a 5W amplifier driving a 100dB@1W@1m speaker.

Unless you have calculated the maximum cone movement, and found out how much (or how little) power it takes to move the cone to its maximum displacement, all that power may be converted only to heat.
This online calculator https://speakerboxlite.com/subwoofer-box-calculator/tab-graphs will help.
 

dendad

Joined Feb 20, 2016
3,617
With the Tannoy 15" Monitor Gold speakers I purchased 45+ years ago, a 20W (RMS) amp is more that enough. They are rated at 85W (RMS, not Advertising Department Power). Speaker efficiency is a good place to start.
500W seems quite excessive to me. I for one do not understand how folk like to damage their ears with loud noise. One of my friends had ear damage caused from work place noise. He had a "hole" in his frequency response so he had trouble hearing a phone ringing, even when standing next to it.
A good rule of thumb I have maintained is to have an amplifier of less output power than the speaker max so as not to damage the speaker.
Still, some people must have armor plated eardrums.
 

Audioguru again

Joined Oct 21, 2019
2,061
"As loud as it can" means the speaker will not produce music or voices.
A truck's air horn is made to go as loud as it can.

Music and voice needs a wide frequency response, a wide dynamic range and very low distortion. The power rating of some amplifiers and speakers is momentary peak power with the volume control turned up way too high so there is severe distortion. True power is a continuous sinewave at low distortion. Then your "500W" is actually 100W or less of true power.

Not stereo and not surround sound?
 

Thread Starter

nikolopikolo

Joined Sep 17, 2020
9
Alright I see that everyone thinks 500 is over the top, so I will lower the overall power by atleast a half.

I got this idea that I can make seperate anplifiers for each driver channel, so like the sub would have its own amp and then the rest of the drivers would have their own amp. I think this would be easier. Now i want to know is it alright if i use one PSU on both of this amps?

Thanks for all the answers
Nik
 

Ian0

Joined Aug 7, 2020
750
Yes. Just like using the same supply for both channels of a stereo amplifier.
However - you might need more power on the bass, so you could use a lower voltage power supply for treble.
A good approximation for audio is equal power per octave, so the power for each channel depends on the crossover frequency; but it is complicated by the fact that higher-frequency speakers tend to be more efficient than lower-frequency speakers.
 

Audioguru again

Joined Oct 21, 2019
2,061
250W sounds only a little less loud than 500W because the sensitivity of our hearing is logarithmic (so we can hear a faint whisper and also hear things that are very loud). 50W sounds half as loud as 500W. Hundreds of Watts will deafen you and break most windows in your home.
 

schmitt trigger

Joined Jul 12, 2010
330
If you want to make an 8 foot diameter mirror for a telescope you can reach that goal faster, by first building a series of smaller mirrors of 1', 2', and 4' in diameter.
Exactly!
When someone in this or other forums asks for advice -for instance, on how to build a 2 kW power supply, the first advice one should provide is: “Have you successfully built a smaller unit that actually works?” Before continuing any further.
 

Ian0

Joined Aug 7, 2020
750
Exactly!
When someone in this or other forums asks for advice -for instance, on how to build a 2 kW power supply, the first advice one should provide is: “Have you successfully built a smaller unit that actually works?” Before continuing any further.
And if the answer is “yes” then they would probably realise that all that was needed as to make it like the first one, but bigger. So we presume that the answer would be “no”.
 

MisterBill2

Joined Jan 23, 2018
7,306
There are circuits published for high powered amplifiers but exactly as mentioned much earlier, they do not include the analysis or other advice. Thus without a whole lot of insight and understanding it will not provide any working amplifier.
AND ALL of the very high powered sound systems in cars that I have heard were used to deliver sound that was grossly offensive by any standards.
 

Audioguru again

Joined Oct 21, 2019
2,061
I have never been inside a car that was playing a high power audio system. Instead I hear one as it drives past me.
Mist car radios have amplifiers that produce 14W into 4 ohms and they have 4 of these amplifiers with 4 ohm speakers.
then the total power of 56W is very loud.

I had a Chevrolet Cobalt with a deluxe Pioneer sound system. It had 4 amplifiers producing 25W into four 2 ohm speakers and a 10" sub-woofer with an amplifier producing 70W. It sounded great. I never turned it up to maximum.
 

MisterBill2

Joined Jan 23, 2018
7,306
I was referencing those vehicles with perhaps 4 or six channels, each channel amplifier being 400 watts or more. Those are the ones that can be heard long before they can be seen. Consider that six channels at 400 watts each is 2400 watts, that is far too loud, but they would play their stuff at full volume, forcing their very poor choices on the rest of us.
 

Audioguru again

Joined Oct 21, 2019
2,061
Few cars produce loud transmission noises but many cars have their mufflers removed to be extremely loud and even produce backfire explosions. The idiot owners even have the pollution controls removed to produce the stink of cars from the '60ies.

I asked a policeman why they don't arrest the drivers of those very noisy cars and he said they did last month. They caught and fined over 1000 idiots but the fines are simply an additional cost of them driving the noisy cars. Most of the noisy cars are new and very expensive. The idiots who drive them (all night long) have more money than brains.
 

MisterBill2

Joined Jan 23, 2018
7,306
Few cars produce loud transmission noises but many cars have their mufflers removed to be extremely loud and even produce backfire explosions. The idiot owners even have the pollution controls removed to produce the stink of cars from the '60ies.

I asked a policeman why they don't arrest the drivers of those very noisy cars and he said they did last month. They caught and fined over 1000 idiots but the fines are simply an additional cost of them driving the noisy cars. Most of the noisy cars are new and very expensive. The idiots who drive them (all night long) have more money than brains.
What part of the world is that in, what you describe, A.G??? Not around my area.
 

Audioguru again

Joined Oct 21, 2019
2,061
Here in a suburb of Toronto, Canada there are fools driving new Ford Mustang cars made here that have three buttons: loud, louder and loudest. There are wealthy Chinese kids at the local University driving Lamborghinis, Ferraris and other very expensive and noisy sport cars. They drive these noisy cars all night long. They are caught street racing and stunt driving but they pay a fine and do it again and again.

My daughter has a little farm. No noisy cars and no police are there.
 
Top