Distorted sound at high volume levels, what do I need to replace?

Question

I have a Pioneer 2x75watt receiver and 2 sony speakers that allegedly handle 200watts (I say allegedly because I am doubtful they can actually handle that much). When the amp's volume control is turned more than halfway up, I have to disable the amp's S-bass feature, or else the bass will be distorted. When the receiver's volume is over 3/4 up, I need to turn down the bass output, or else the bass will sound terrible. I need to be able to make the bass louder to overcome the loudness of my guests (60+ people in a small room are very loud). Do I need to replace the receiver, the speakers, or both?

Answer 1

Have you given any thought to the fact that if you crank up the music louder than it is now, your guests will end up speaking louder so that they can hear each other? And eventually, what you will be replacing are the batteries in your hearing aids.

Personally, I do not go to concerts to chat with someone and I don't go to parties to listen to music. At a party, the music is basically just background noise. If you want to have both at the same time, you need to provide separates areas for music and chat.

But good luck to you.

Answer 2

It is hard to pinpoint which is the culprit, if not both.

Let's start differently.

First, you need to understand and decide the max Sound Pressure Level (SPL) you want. What's loud for you may be too loud or not enough loud for others.

Good quality speakers will publish their SPL, either the Sensitivity (in dB's) at 1watt 1meter, or the max SPL.

Second let's calculate the Amplifier's Power output needed.

Let's start with a speaker of 90 dB SPL sensitivity and a desired max of 108 SPL.

For every 3dB increase you need to double the power.

1w 90 dB; 2w 93; 4w 96; 8w 99; 16w 102; 32w 105; 64w 108.

Now that's at 1 meter (~3 feet), every time you double the distance the SPL goes down by 6dB.

So at: 3' 108; 6' 102; 12' 96dbSPL.

Once you figure the max SPL and speakers you want, then you can decide what amplifier you want, having in mind that you always want 3dB headroom in the amplifier, that means another doubling of the power, so for the example above you need 128Watts.

If all these sounds a bit too technical to you, is because it is. There is no rule of thumb to figure all these out, unless a very experienced Pro Audio person does it. Sorry. Hope it helps anyway.

Example:

http://www.jbl.com/home/products/product...

This speaker has a sensitivity of 88dBSPL. (It says at 2.83v 1 meter, that's the same that 1W 1 meter, since it is an 8 Ohm speaker.)

Answer 3

The receiver.

Power ratings are complex, but if you read the fine print you will see something like:

"75 watts per channel, all speakers driven, 8 ohm non-inductive load, 0.07% THD".

That "THD" is "Total Harmonic Distortion".

You can crank the volume to produce 80, 90, 100 watts from a "75 watt" amp, But the distortion increases quickly.  And if you run out of power - the sound from your speakers also goes bad because the unit cannot control the speaker motion.

In fact - you are damaging your speakers by using an under-powered amp.  (Not to worry - Sony does not make good speakers anyway).

But buying a 'good' amp from Yamaha, Dennon, Onkyo will solve your distortion problem.