how to increase output power on a 400watt amp

[db junkie]

ok i have a few amps laying around and they all work perfectly and i have just been tryn to figure out how to increase the power the amps push out so i could sum how use the three amps to form a much more powerful amp by sum how using sum of there parts or combining there parts or sumtin if ne one knows how i could do this or if it is even possible id really like to know and be able to do it

[CBS240]

There's an old saying, "If it ain't broke, don't fix it." Design is critical to whether you can just boost rail voltage and actually get more power out, or use different devices to boost SOA so devices don't go "POOooooffff" My suggestion is if you don't know much about design, don't attempt it or you will become upset when it smokes. We don't like people to be upset around here! It may be possible to use the parts to create a compleatly new circuit, but this makes not much sense if they already work, as opposed to just buying new parts or a DIY kit.

Maybe you could split the duty of each amp acording to frequency. Use one for the lower freqs, another for mid range, and another for high range, all with completely different speakers. By cutting the bandwidth of each amp, you can get more efficiency and more gain before clipping the peaks of an audio signal. Full range audio has lots of harmonic peaks compared to where most of the power is. Smaller bandwidth has smaller ratio. Use filters on the inputs according to size of amp and type of speaker. (sub, woofer-low mids, or high mids and tweeter) But you probably already knew that

[amplifierguru]

Hi db junkie,

for what it's worth (what you paid for it?)


400W is lots of power so maybe more efficient speakers or an ear syringe? Possibly both?

Hope that helps,
Greg

[peranders]

db junkie, since you are a dB junkie I'll gather you know the relationship between power and dB?, Yes? If you want 10 dB more sound you must get yourself 4000 watts. If you want only 3 dB, hardly noticable, it's 800 watts.

So... how many dB's do you get right now and how many do you want? It's better to start here to see what you are after really.

[EWorkshop1708]

Assuming by your post, you have Three (3) 400W Amps.

You are wanting to combine them to make bigger power, well the most you could get is 1200W

The proper way to get your total 1200W is to connect speakers to each of the 3 amps, so each drives it's own set of speakers.

3 sets of 400W going into speakers = 1200W.

If you wanna make it easy and have them play full range, then just parallel the inputs to all 3 amps so they play the same.

*Now another approach, is to use 1 400W amp for your main voice and highs speakers, and use the remaining 2 400W amps to drive a 15 or 18" dual coil sub with 800W (400W per coil)

[destroyer X]

Can be assemble fast to invert phase.

The upper amplifier receive the input audio, from the audio source directly.

The lower amplifier will receive the input audio inverted, as one transistor stage will be connected to its input...having gain one, no modifications in audio level...but phase will be inverted.

Those signals, from each amplifier will have almost the same power, the same voltage,but will be inverted.... this way, if you have two 400 watts amplifiers, connecting them in bridge mode, you will have 1568 watts.... 4 times more power.

The speakers wires will be the red ones.... positive output form one channel and positive output form the other channel will be joined in speaker input posts!

All you have is to construct a small inverter....biased with batteries or some voltage you pick from the amplifiers supply.

The problem is that you will have to produce an enormous quantity of speaker in series and parallell, to have 8 ohms again, and if you make mistakes..hummmmm......Booooooom!

Bye bye and farewell your beloved speakers....and you can be electrocuted by the output, that will reach enormous peak to peak voltage...as RMS will be 112!

I will search the input to you if you want it.

nanabrother@yahoo.com

This is a little bit dangerous...but you are free to decide.

here is a link to see the inverter circuit...and before this post, there are others informations that can be aplied to your needs.

http://www.diyaudio.com/forums/showt...418#post721418

regards,

Carlos

[peranders]

Originally posted by destroyer X
Those signals, from each amplifier will have almost the same power, the same voltage,but will be inverted.... this way, if you have two 400 watts amplifiers, connecting them in bridge mode, you will have 1568 watts.... 4 times more power.

This is valid under certain circumstances, so it's not a rule.

[destroyer X]

And this produces the power he need, but quality.... hummmm...not so good.... and the reason why must be the exceptions you told us.

regards,

Carlos

[AndrewT]

Hi Destroyer,
yes you can bridge two identical amps.
They then produce twice the power into twice the impedance. You forgot to tell him that.

You also forgot to warn the thread starter that a briged amp draws extremely high current from both amps when asked to drive a standard load impedance (the one printed on the back of the amp, usually 4 to 8 ohms).

You also forgot to tell him that he would probably damage his amps if he did not take account of the information you supplied and didn't supply him. It would have been far better to have never raised the bridging option if you are not prepared to also give the necessary warnings or conditions.

[destroyer X]

Good that you had the attention to complete my idea...tell him all those details please.

regards,

Carlos