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| WHY I USE TONE CONTROLS by Richard S. Burwen |
Audiophiles rarely include tone controls in their systems. Why do I use them?
Two main reasons:
My audio system is imperfect.
My program material has huge variations in sound.
AUDIO SYSTEM
My speaker system consists of five walk-in speaker horns, each 13 feet deep; the front horns each have an 8 x 8 ft mouth. Altogether it has 169 woofers,
sub-woofers, mid range horns, and tweeters. I spent a year adjusting the frequency response of the 18-circuit board, 4-way electronic crossover so that a
recording of my son Russ playing drums in the front center horn was hard to distinguish from the real drums. One day when I played back a recording at a
higher level than Russ played, a light bulb above shattered all over him.
On a few occasions when I played back my own live recordings I was amazed at how accurate the sound seemed. I had equalized the speakers very
well. Yet when I played CDs and other live recordings the sound was not right. It was often thin, too bright, or strident - even irritating. Something was
wrong.
Some of the CDs that were too bright on my system seemed OK in headphones and on some other speaker systems. I think the difference may be that
speaker manufacturers are learning that many CDs have too much high frequency content and they are equalizing the frequency response of their
speakers slightly downward at higher frequencies to compensate. In most recordings, the high frequencies are inherently too strong because microphone
placement picks up more than the audience hears.
Regardless of the cause, I found the strident recordings could be greatly improved via tone controls.
VARIATIONS IN PROGRAM MATERIAL
Andre Rieu is my favorite entertainer. He plays my favorite music. I purchased every one of his CDs and DVDs I could find and I play them again and
again. Although I would love to hear his Johann Strauss Orchestra in a live concert, I may never go to one. He plays in such huge venues to so many
thousands of people that I expect the sound will be terrible.
Among his recordings I own a few that I play with slight treble attenuation. Two others recorded in different places are very thin and screechy. It is not
the way orchestra played - the same piece played with practically the same arrangement sounds entirely different. Even though the acoustic environment
was quite different, I cannot imagine that the sound of the orchestra even resembled what is on the CDs. With tone controls I am able re-balance Andre
Rieu's worst recordings so they sound more like his best recordings. Otherwise I would never play them.
TENTHS OF A DB ARE IMPORTANT
Here is little story. One of my most favorite recordings and a powerful demonstrator is my own live concert recording of Mahler's Symphony 6, played by
the Boston Philharmonic in Jordan Hall at the New England Conservatory in 1986. One of the instruments of the orchestra is sledge hammer! For each of
Mahler's 3 blows of fate in the final movement, a muscular guy took a full swing and struck a whopping big anvil on the front of the stage. My two special
omnidirectional microphones, pointed at the ceiling to get high frequency sound reflections, captured it well.
This was a 2-channel recording made on a Sony PCMF1 machine, now made into 5 channels using my AUDIO SPLENDOR program which added
ambiance in the rear and front channels. It was saved as a 6-channel 88.2 kHz music file. I love this recording so much I had re-mastered it 6 times,
each time improving the sound for my own studio. After the 7th re-mastering I called my wife Barbara down to hear this great symphony and sound.
She sat in the center seat and I sat beside her. When the recording played, the violins no longer sounded quite right. I thought about one more re-
mastering. After my concert finished and Barbara went upstairs I embarked on fixing the violins. I played the offending musical passages again, but this
time the violins sounded good.
I had been using quite a lot of rear speaker sound to add to front channel sound at the listening sofa and sweeten the violins. When Barbara sat in the
center seat she partially blocked sound from the right rear speaker.
I figured out what to do. People damage the sound by absorbing and blocking it. So no more visitors will be allowed.
Well, that conflicts with the purpose of my sound studio. Once again I re-mastered Mahler’s 6th, increasing the EXTREME reverb 0.2 dB in all channels,
and increasing the rear channel gain 0.8 dB, and tweaking the EQ sliders a few tenths of a dB. I spent the last 15 minutes deciding on a 0.1 dB increase
in the 3 kHz slider. Without it the orchestra was more natural. With it the cymbals were more natural.
Two main reasons:
My audio system is imperfect.
My program material has huge variations in sound.
AUDIO SYSTEM
My speaker system consists of five walk-in speaker horns, each 13 feet deep; the front horns each have an 8 x 8 ft mouth. Altogether it has 169 woofers,
sub-woofers, mid range horns, and tweeters. I spent a year adjusting the frequency response of the 18-circuit board, 4-way electronic crossover so that a
recording of my son Russ playing drums in the front center horn was hard to distinguish from the real drums. One day when I played back a recording at a
higher level than Russ played, a light bulb above shattered all over him.
On a few occasions when I played back my own live recordings I was amazed at how accurate the sound seemed. I had equalized the speakers very
well. Yet when I played CDs and other live recordings the sound was not right. It was often thin, too bright, or strident - even irritating. Something was
wrong.
Some of the CDs that were too bright on my system seemed OK in headphones and on some other speaker systems. I think the difference may be that
speaker manufacturers are learning that many CDs have too much high frequency content and they are equalizing the frequency response of their
speakers slightly downward at higher frequencies to compensate. In most recordings, the high frequencies are inherently too strong because microphone
placement picks up more than the audience hears.
Regardless of the cause, I found the strident recordings could be greatly improved via tone controls.
VARIATIONS IN PROGRAM MATERIAL
Andre Rieu is my favorite entertainer. He plays my favorite music. I purchased every one of his CDs and DVDs I could find and I play them again and
again. Although I would love to hear his Johann Strauss Orchestra in a live concert, I may never go to one. He plays in such huge venues to so many
thousands of people that I expect the sound will be terrible.
Among his recordings I own a few that I play with slight treble attenuation. Two others recorded in different places are very thin and screechy. It is not
the way orchestra played - the same piece played with practically the same arrangement sounds entirely different. Even though the acoustic environment
was quite different, I cannot imagine that the sound of the orchestra even resembled what is on the CDs. With tone controls I am able re-balance Andre
Rieu's worst recordings so they sound more like his best recordings. Otherwise I would never play them.
TENTHS OF A DB ARE IMPORTANT
Here is little story. One of my most favorite recordings and a powerful demonstrator is my own live concert recording of Mahler's Symphony 6, played by
the Boston Philharmonic in Jordan Hall at the New England Conservatory in 1986. One of the instruments of the orchestra is sledge hammer! For each of
Mahler's 3 blows of fate in the final movement, a muscular guy took a full swing and struck a whopping big anvil on the front of the stage. My two special
omnidirectional microphones, pointed at the ceiling to get high frequency sound reflections, captured it well.
This was a 2-channel recording made on a Sony PCMF1 machine, now made into 5 channels using my AUDIO SPLENDOR program which added
ambiance in the rear and front channels. It was saved as a 6-channel 88.2 kHz music file. I love this recording so much I had re-mastered it 6 times,
each time improving the sound for my own studio. After the 7th re-mastering I called my wife Barbara down to hear this great symphony and sound.
She sat in the center seat and I sat beside her. When the recording played, the violins no longer sounded quite right. I thought about one more re-
mastering. After my concert finished and Barbara went upstairs I embarked on fixing the violins. I played the offending musical passages again, but this
time the violins sounded good.
I had been using quite a lot of rear speaker sound to add to front channel sound at the listening sofa and sweeten the violins. When Barbara sat in the
center seat she partially blocked sound from the right rear speaker.
I figured out what to do. People damage the sound by absorbing and blocking it. So no more visitors will be allowed.
Well, that conflicts with the purpose of my sound studio. Once again I re-mastered Mahler’s 6th, increasing the EXTREME reverb 0.2 dB in all channels,
and increasing the rear channel gain 0.8 dB, and tweaking the EQ sliders a few tenths of a dB. I spent the last 15 minutes deciding on a 0.1 dB increase
in the 3 kHz slider. Without it the orchestra was more natural. With it the cymbals were more natural.