Usage of Equalizers

Muthusami S

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Dear friends,

I thought of this question for a long time in my mind. What is the role of equalizers in audio listening/recording. Is it mandatory to use equalizers for good audio quality because musical shops are using equalizer for recording. During my college days I used to make cassette collections by recording songs from musical shops. There I found equalizers for every recording unit (Connected as Turntable > Equalizer > Recording deck > amplifiers > speakers). As the tracks in vinyl records are recorded high quality, does it make any sense in using the equalizers. For equalizer recording, they charge additionally.

After my college days, me and our friends started a recording shop and we also followed the same method.

Is there any value addition using equalizers for listening or recording. Looking forward to your views regarding this issue.

Regards,
Muthusami. S
 
Dear friends,

I thought of this question for a long time in my mind. What is the role of equalizers in audio listening/recording. Is it mandatory to use equalizers for good audio quality because musical shops are using equalizer for recording. During my college days I used to make cassette collections by recording songs from musical shops. There I found equalizers for every recording unit (Connected as Turntable > Equalizer > Recording deck > amplifiers > speakers). As the tracks in vinyl records are recorded high quality, does it make any sense in using the equalizers. For equalizer recording, they charge additionally.

After my college days, me and our friends started a recording shop and we also followed the same method.

Is there any value addition using equalizers for listening or recording. Looking forward to your views regarding this issue.

Regards,
Muthusami. S

Hi,
I guess it may have helped in flat recordings where the user could boost the lacking frequency.
The BIAS TUNE on some decks could achieve similar as that too is like a tilt towards either frequency.
In a decent system i would avoid artificially boosting certain frequencies and hence would avoid using an equalizer for playback. In my opinion it would not have any value addition.
I regularly visited a CD/LP library in mumbai called Melody ages ago and they would record for a small charge. When they recorded on tape they turned the bias knob to enhance the trebles as they claimed the customers demanded a treble boost while i preferred to record flat or as is.
Maybe there could be some value addition in recording esp if doing it commercially but not so for playback IMO.
Regards
 
Dinyaar,

Thank you very much for the clarification. I was about to purchase an equalizer and now I found it is unnecessary. Thanks a lot.

Regards,
Muthusami. S

Hi,
I guess it may have helped in flat recordings where the user could boost the lacking frequency.
The BIAS TUNE on some decks could achieve similar as that too is like a tilt towards either frequency.
In a decent system i would avoid artificially boosting certain frequencies and hence would avoid using an equalizer for playback. In my opinion it would not have any value addition.
I regularly visited a CD/LP library in mumbai called Melody ages ago and they would record for a small charge. When they recorded on tape they turned the bias knob to enhance the trebles as they claimed the customers demanded a treble boost while i preferred to record flat or as is.
Maybe there could be some value addition in recording esp if doing it commercially but not so for playback IMO.
Regards
 
Dear All

Since all audiophiles suggest not to add an equalizer to your component chain, may I suggest the T-Qualizer which is an equalizer which you can wear while listening to the music.
I sell these t-shirts at my website and also make wall posters of the same to be used in the Stereo/HomeTheatre rooms. Please check my website at Ray Store and let me know what you think.

Regards
Rahul Pandit
Ray Store
 
Hi Rahul,

The products are innovative; will purchase through online if needed.

Thanks,
Muthusami. S

Dear All

Since all audiophiles suggest not to add an equalizer to your component chain, may I suggest the T-Qualizer which is an equalizer which you can wear while listening to the music.
I sell these t-shirts at my website and also make wall posters of the same to be used in the Stereo/HomeTheatre rooms. Please check my website at Ray Store and let me know what you think.

Regards
Rahul Pandit
Ray Store
 
Dinyaar and Anil Kumar has given you some good answers.

Unfortunately my fingers itch too much to keep away from the keyboard. Sorry Dinyaar and Anil. I just have to add my two bit to this. No offense meant.

At the outset, there is a bit of contusion on the terminology.

The term ??equalizer?? is often erroneously used, Audio components and mixing equipment include the so-called graphic equalizers, or simply, equalizers. These are actually general all-purpose filters. Divided into a number of frequencies, these filters produce the effect of high-pass, low-pass, bandpass and band-stop filters. These filters function as equalizers only when their mode of arrangement is such that they reverse the effects of the internal circuitry on the output.

The control of frequency loss or gain is only a small part of an equalizers. The main function is to counter balance the unequal frequency response of an external signal processing system. Using an equalizer, you can adjust one or more parameters that are determinants to the overall shape of the filter's functioning. Equalization filters are generally used to enhance sound fidelity, eliminate undesired components in the signal, emphasize certain instruments, and develop completely new sounds.

Equalizer filters are of multiple type - namely peaking filters, shelving filters, low-pass and high-pass, and band-pass filters.

Peaking filters work on frequencies, 'Q. and Boost/Cut. The peaking filter uses a bell curve and functions smoothly over a wide frequency range. The center frequency, occurring at the crest of the bell, is the one affected by the equalization. Frequency, as you know, is measured in Hertz. 'Q' is a quality factor that refers to the width of the bell curve. Q is inversely proportional to the bandwidth - a higher Q denotes that only a few frequencies are affected and vice versa. Q is generally measured in Octaves. Boost/Cut, also called, gain, determines the amount of selected frequencies that should be present. A boost enhances the presence of the frequencies, while a cut softens the frequencies. A gain of +10dB indicates doubling of the amplitude of the original sound.

Shelving Filters are used to cut or boost a determined frequency till a preset level is reached. The same level is then applied to the rest of the frequency spectrum. Shelving filters are common on the treble and bass controls of home audio systems, and are also employed in audio mastering.

High-pass and Low-pass filters are used to boost or cut frequencies above or below a set frequency termed as the cutoff frequency. High pass filters allow the frequencies above the cutoff frequency to pass through unaffected. Frequencies that fall below the cutoff are attenuated at a constant rate per octave. Low-pass filters, on the contrary, allow frequencies below the cutoff to pass through unaffected.

High-pass and low-pass filters are used to eliminate pops, reduce noise, and remove rumble.

A bandpass filter is simply a combination of one low-pass filter and one high-pass filter. Band-pass filters allow frequencies that fall within a certain range and reject all others. An RLC circuit such as those used in AM/FM radio to tune to a particular radio frequency, uses bandpass filter extensively.

Parametric Equalizers

A parametric equalizer is used in live sound reproduction, in public address systems and, in sound recording. Parametric equalizers enable audio engineers to control the parameters such as the center frequency, amplitude and bandwidth of the internal bandpass filters. A parametric equalizer allows the amplitude of each band to be controlled, and the center frequency to be widened, narrowed or shifted.

A parametric equaliser

1. removes excessive unwanted resonance, which can cause a ??boomy?? sound found in musical instruments such as double basses and acoustic guitars.
2. eliminates undesirable elements such as foreign noises.
3. eliminates feedback that causes an excessive resonance (or what we hear as shriek). This usually happens in live performances when amplified sound is captured by a microphone.
4. can be used for tonal enhancements. For, example a tampura player usually sits behind the main artists and does not have a separate microphone. At the same time, the sound of the tampura is important for the rhythm of the music. The equaliser can boost the sound of the tampura before it is cut into a CD or tape.

Graphic equalisers use slide potentiometers to gain control. In addition they may have a display that shows the frequency curve in real time.

Applications of Equalizers

One of the most important use of equalizers is in live performances where speakers and microphone operate together. Here the equalizer is used to eliminate feedback causing frequency bands.

Equalizers are frequently used in public address systems and in places such as churches, temples, stadiums, sports arenas. etc. Here equalizers are used to sharpen the sound. Temporary structures will need equalizers as it is impossible to build a good system in such places. Studios invariably use equalizers to coordinate the various microphones and sound inputs into the system, and to reduce and eliminate external noises such as a hum. .

As Dinyaar and Anil have said, at present times, the equalizers as we know them do not have much use in a home environment. Speakers have full bandwidth capabilities and excellent crossover inside eliminating the need to boost or cut a frequency. Similarly, amplifiers have reached level of sophistication where their internal circuitry takes care of smoothening across frequencies, if required. Modern AVR have a set-up system (such as from Audessey) that give a feedback to the system about the room, so that the amplifier can handle the room acoustics.

There may yet be a small set of people who demand amplified low frequencies. For such people using a filter to boost low frequencies when you record for them may make sense. But for those who value high fidelity, we always listen to music without any artificial attenuation. Whenever I audition equipment, I ensure that the demo equipment are all set to flat so that I can hear the natural capabilities of the source, the amplifier, the connectors/cables, and the speakers.

In your business Muthusami, whether to have a equalizer or not depends upon the kind of customers you deal with. If there is a high percentage of people who are happy with artificial frequency boosting, then I suppose that is what you have to give them.

Cheers.
 
Nice explanation. Thank you very much. By the way, I am not in the recording business now; only for my personal use, I planned to buy an equalizer. In my business I had Akai 10+10 band graphic equalizer. Without any technical knowledge, we managed to bring quality recording by adjusting the bands.

Thanks again.

Regards,
Muthusami. S

Dinyaar and Anil Kumar has given you some good answers.

Unfortunately my fingers itch too much to keep away from the keyboard. Sorry Dinyaar and Anil. I just have to add my two bit to this. No offense meant.

At the outset, there is a bit of contusion on the terminology.

The term ??equalizer?? is often erroneously used, Audio components and mixing equipment include the so-called graphic equalizers, or simply, equalizers. These are actually general all-purpose filters. Divided into a number of frequencies, these filters produce the effect of high-pass, low-pass, bandpass and band-stop filters. These filters function as equalizers only when their mode of arrangement is such that they reverse the effects of the internal circuitry on the output.

The control of frequency loss or gain is only a small part of an equalizers. The main function is to counter balance the unequal frequency response of an external signal processing system. Using an equalizer, you can adjust one or more parameters that are determinants to the overall shape of the filter's functioning. Equalization filters are generally used to enhance sound fidelity, eliminate undesired components in the signal, emphasize certain instruments, and develop completely new sounds.

Equalizer filters are of multiple type - namely peaking filters, shelving filters, low-pass and high-pass, and band-pass filters.

Peaking filters work on frequencies, 'Q. and Boost/Cut. The peaking filter uses a bell curve and functions smoothly over a wide frequency range. The center frequency, occurring at the crest of the bell, is the one affected by the equalization. Frequency, as you know, is measured in Hertz. 'Q' is a quality factor that refers to the width of the bell curve. Q is inversely proportional to the bandwidth - a higher Q denotes that only a few frequencies are affected and vice versa. Q is generally measured in Octaves. Boost/Cut, also called, gain, determines the amount of selected frequencies that should be present. A boost enhances the presence of the frequencies, while a cut softens the frequencies. A gain of +10dB indicates doubling of the amplitude of the original sound.

Shelving Filters are used to cut or boost a determined frequency till a preset level is reached. The same level is then applied to the rest of the frequency spectrum. Shelving filters are common on the treble and bass controls of home audio systems, and are also employed in audio mastering.

High-pass and Low-pass filters are used to boost or cut frequencies above or below a set frequency termed as the cutoff frequency. High pass filters allow the frequencies above the cutoff frequency to pass through unaffected. Frequencies that fall below the cutoff are attenuated at a constant rate per octave. Low-pass filters, on the contrary, allow frequencies below the cutoff to pass through unaffected.

High-pass and low-pass filters are used to eliminate pops, reduce noise, and remove rumble.

A bandpass filter is simply a combination of one low-pass filter and one high-pass filter. Band-pass filters allow frequencies that fall within a certain range and reject all others. An RLC circuit such as those used in AM/FM radio to tune to a particular radio frequency, uses bandpass filter extensively.

Parametric Equalizers

A parametric equalizer is used in live sound reproduction, in public address systems and, in sound recording. Parametric equalizers enable audio engineers to control the parameters such as the center frequency, amplitude and bandwidth of the internal bandpass filters. A parametric equalizer allows the amplitude of each band to be controlled, and the center frequency to be widened, narrowed or shifted.

A parametric equaliser

1. removes excessive unwanted resonance, which can cause a ??boomy?? sound found in musical instruments such as double basses and acoustic guitars.
2. eliminates undesirable elements such as foreign noises.
3. eliminates feedback that causes an excessive resonance (or what we hear as shriek). This usually happens in live performances when amplified sound is captured by a microphone.
4. can be used for tonal enhancements. For, example a tampura player usually sits behind the main artists and does not have a separate microphone. At the same time, the sound of the tampura is important for the rhythm of the music. The equaliser can boost the sound of the tampura before it is cut into a CD or tape.

Graphic equalisers use slide potentiometers to gain control. In addition they may have a display that shows the frequency curve in real time.

Applications of Equalizers

One of the most important use of equalizers is in live performances where speakers and microphone operate together. Here the equalizer is used to eliminate feedback causing frequency bands.

Equalizers are frequently used in public address systems and in places such as churches, temples, stadiums, sports arenas. etc. Here equalizers are used to sharpen the sound. Temporary structures will need equalizers as it is impossible to build a good system in such places. Studios invariably use equalizers to coordinate the various microphones and sound inputs into the system, and to reduce and eliminate external noises such as a hum. .

As Dinyaar and Anil have said, at present times, the equalizers as we know them do not have much use in a home environment. Speakers have full bandwidth capabilities and excellent crossover inside eliminating the need to boost or cut a frequency. Similarly, amplifiers have reached level of sophistication where their internal circuitry takes care of smoothening across frequencies, if required. Modern AVR have a set-up system (such as from Audessey) that give a feedback to the system about the room, so that the amplifier can handle the room acoustics.

There may yet be a small set of people who demand amplified low frequencies. For such people using a filter to boost low frequencies when you record for them may make sense. But for those who value high fidelity, we always listen to music without any artificial attenuation. Whenever I audition equipment, I ensure that the demo equipment are all set to flat so that I can hear the natural capabilities of the source, the amplifier, the connectors/cables, and the speakers.

In your business Muthusami, whether to have a equalizer or not depends upon the kind of customers you deal with. If there is a high percentage of people who are happy with artificial frequency boosting, then I suppose that is what you have to give them.

Cheers.
 
Hi venkat, thanks for the info. My comment on eq for home use only.....
@ my office i work on protools & adobe audition for audio editing work & use eq (30 bands 1\3 octave) for voice overs & background music. I was using Technics eq with Onkyo prologic amp for 8 years, sound was artificial, i did not like it. For this reason i bought vintage Pioneer & Yamaha 2 channel amps, sounds classic & sweet without eq:). If you audition my Pioneer & Yamahas you will start hating graphic equalizers.

Anil
 
Re Equalisers for home Playback systems.
While I generally agree with the tenor of the posts, viz, that its best to have a flat output, sometimes an equaliser can be pretty useful.
E.g, I am very fond of Hindustani classical music & have several tapes/CDs where the output with flat settings is unlistenable.
In such cases, by tweaking the equaliser in my Pre Amp, I am able to get a much better sound & am able to enjoy a Masters' performance.
Given a choice, I much prefer this approach over denying myself the pleasure of such performances.
So, if you are in a similar situation, an Equaliser can come in handy
 
Hi Kamal,

Thank you very much for the information.

Regards,
Muthusami. S

Re Equalisers for home Playback systems.
While I generally agree with the tenor of the posts, viz, that its best to have a flat output, sometimes an equaliser can be pretty useful.
E.g, I am very fond of Hindustani classical music & have several tapes/CDs where the output with flat settings is unlistenable.
In such cases, by tweaking the equaliser in my Pre Amp, I am able to get a much better sound & am able to enjoy a Masters' performance.
Given a choice, I much prefer this approach over denying myself the pleasure of such performances.
So, if you are in a similar situation, an Equaliser can come in handy
 
Kamal and Anil, I agree with both you. A PC based equalizer is very essential for mixing and other work that is done professionally.

Similarly, at times, I feel that Latha's voice, for example, is very shrill in some songs. In such situations, a filter to tone down the high frequency will be a great boon.

But today, more and more music is being delivered on an 'as is' basis, and we expect the audio equipment to bring out a 'warm' sound from the music.

I have heard a number of cars driven by college boys that seem to have an unnaturally high base that drowns out all other sound. So much so that the glasses rattle. Similar situation is in discos where the low frequencies are boosted, and the whole music is at a volume loud enough to make you go deaf. But I suppose the environment demands that.

Some time ago I attended a live performance of Jethro Tull in an open ground in Bangalore. They had set up barricades in a way that the audience was a minimum 12 feet away. The sound system was so good that you could clearly hear when Tull was playing at low volumes and, and at the same time enjoy his whole orchestra blasting away.

Last week I attended a live music by a local group called Friends Orchestra. This was done in a good auditorium that had just spent nearly a crore doing up the acoustics with consulting from Bose.. The orchestra, instead of using the auditorium's sound system, used their own mixers and speakers. I could not sit through the concert after the third song.

My worry is, in an attempt to have short term enjoyment or impress somebody else, are we losing our capabilities to really enjoy music? That is the reason I prefer to see movies at home. In cinema halls the ambient noise is so much that the volume has to be kept high. In spite of that you cannot hear dialogues properly, and the high volume sound starts hurting your ears.
 
Venkat, I hear where you're coming from.
Believe me, I use the equaliser only when I have no other option,i.e when the recording/mastering has not been done properly so you're faced with boominess or muffled highs or where the mids are overshadowed by lower freqs.
I too have a feeling of concern when youngsters blast their eardrums in the close confines of a car etc & cinema halls, esp multiplexes blast your ears with loud volumes.
The best you can do is to act sensibly yourself & thus set a good example.
 
Believe me, I use the equaliser only when I have no other option,i.e when the recording/mastering has not been done properly so you're faced with boominess or muffled highs or where the mids are overshadowed by lower freqs.

Kamal,
you are just reflecting my views..We definetly need Graphic equalizer to hear/record poorly recorded masters.I have around 250 original and recorded cassetes at my Home.Almost all of the recordings were done through Graphic equalizers.

Lot of 80 and 90's Tamil recordings were poor in quality eventhough songs were very nice.In this case G-equalizer is helping lot to enhance the frequencies..I used to sit and timepass in One of my friends Musicals (recording center) at my native,That guy used to say LP records are very good compared with tape and for recording Master cassatte to cassate we should need G-equalizer.Some of the IlayaRaja's recording were very good in recording quality eg. Mella Thiranthau Kadhavu,Ninaivellam Nidya and Alaigal Ooivathillai.My friend used to adjust down his equalizer settings for these songs..

I still remember, The same poorly recorded song which I didn't like to listen were sounded in different and awesome tone through G-Equalizer.So,again it is listener's interest.My opinion is we can have Graphic equalizer to hear poor recordings.

I will definetly buy one for my HiFi..

Cheers,
Pandiyan
 
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Hi. You guys are talking about good quality equipment that reproduce the original recording faithfully. :) I have a pretty decent amplifier and graphic equaliser, but my speakers are sadly inadequate.

The low frequencies have little definition, but are too loud nonetheless. So, I am forced to use my graphic equalisers pretty drastically to subdue this anomaly.
 
Prabu wrote-
"The low frequencies have little definition, but are too loud nonetheless. So, I am forced to use my graphic equalisers pretty drastically to subdue this anomaly"
Prabu, in case you are forced to do this even with well recorded CDs,then you need to upgrade your speakers,else you will keep denying yourself the pleasure of enjoying the beauty of a superb recording of a great Master.
 
I couldn't agree with you more, Kamal. I seriously need to upgrade my speakers. Actually, even the amp.

You know how I found this forum? My amp was misbehaving after years of service, and I tried finding someone to repair it. No progress. So, I tried searching the net. Google would throw up the name of Hifivision every time. That got me curious, and I kept browsing here.

I suppose I shall start a separate thread regarding my amp. What I have is an Akai AM 27 amp and an Akai EA 27 10+10 equaliser. Both are beginning to fail now. The speakers are Philips, which I have never liked. How I bought the speakers, is a long story and a waste of time. Its just the amp and the equaliser that made the speakers tolerable. Visitors often compliment me on the nice sound, but all I can do is smile sadly. (At least for now)
 
Dear Muthusami

I was using Eq during my college days as well , there was lot of Cassettes and some LPs in which the recording is not quite good., i ws using the Eq in a V shape and later found it incorrect , i was using Altec Lancing , Technics eqs for a long time ( only for bad recordings ) . But now a days i not using the Eqs and infact sold the Technics for Rs.500/- ( i was even ready to give it free )

A good recorded LPs or casettes or Cds dont need any eqs . IMO

regards

David.
 
Purchase the Audiolab 6000A Integrated Amplifier at a special offer price.
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