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Hi All,What are the pros/cons of using an equalizer to smooth out the frequency response? I think I've done everything possible in my listening room as far as tweeks, etc, but I'm still left with several deeps and peaks.
I have practically zero knowledge of equalizers and have noticed most people just don't use them much. Why is this?
Thanks,
Follow Ups:
For whatever reason, this topic continues to re-surface year after year. Maybe the magazines are on to something: there's a new crop of newbies and budding audiophiles every year. It's almost like being in the same school grade year after. Which is why I don't subscribe to any "stereo" magazines anymore: "There's no new there." Other than specific product reviews, I think the mags could just recycle their old articles every year. Come to think of it, I think that's exactly what they do. Anyway...EQ is short for "equalization". Equalizers have been around since the first "tone control". That's what they are: tone controls. Some are elaborate, like five band parametrics with a switchable LF cut. Some are simple, like "bass and treble". Some are in between. Some are 30 bands of "bass and treble", i.e., graphic equalizers where each filter affects a relatively small frequency range.
But in ALL cases, what they do is to adjust the level of specific frequency ranges. And that involves not only amplitude, but also phase.
Rooms cannot be "EQ'd". Only audio systems can be EQ'd, and even then only if you're willing to live with the phase change, and are happy with listening in a certain few small areas of the room.
As far as the room is concerned, that's a time and resonance issue, not a level issue. Unfortunately, most audiophiles and so-called "professionals" still don't get that.
But EQ *can* make problems not hurt as much.
I've lived with my new PARC, and new speakers for that matter, for about 12 hours. I bought MBL 101e's, and the dealer basically did a Rives evaluation of my room. We played with speaker placement, which was somewhat constrained by the fact that it has to double as home theater mains, speaker height (spikes and ultimately a stand) and toe-in, not really supposed to matter with omni-directional speakers, but guess what.
After every change, he re-measured with the Rives equipment. Everything makes a difference. Finally, he inserted a PARC, and the effects were amazing. So much so that after a few tries, I couldn't listen without it. My room is treated, but apparently I would need to go to a whole new level to even try to come close. Of course, I bought a new PARC on the spot. My dealer warned me about break-in time. For a wholly electronic device, I think I'm probably breaking in my ears, rather than the unit, but who cares. I had the experience , pretty weird actually, of listening to a cut I've heard hundreds of times, and hearing a new instrument in the mix. It was aways there, but I couldn't hear it before. My previous speakers were Avalon Osiris and Dynaudio Temptations, so I don't think they were the problem.
David Shapiro
nt
See:http://www.AudioAsylum.com/audio/tweaks/messages/17541.html
Let me add to that post here.
First, not every one has access to SLM's or mics, and for them, EQing by ear using a test tone CD with warble tones or 1/3 octave bands of pink noise would be just as good, IF NOT BETTER, than using an SLM and doing it By The Numbers. Just match the levels of the test bands to a central frequency band such as 1 kHz or 400 or 500 Hz (depends on whether it is 1/3 octave or 1 octave bands being used) by ear at your listening position. Many folks seem to have more problems trying to EQ by referencing to 1 kHz, and should use 400 Hz or 500 Hz as the reference band instead.
Second, many people do not seem to understand WHY you can not EQ the room, this is because there is a fundamental problem with trying to boost a frquency region that has a suck-out due to acoustic cancellation. No mater what you do with the EQ, the acoustic cancellation is still there, and all you can do is bring up the energy AROUND that cancellation frequency, which kinda-sorta helps compensate, even though it is really a case of two wrongs do not make a right.
While cutting a boosted region can be accomplished, if the boost is a result of an acoustic issue in the room, or some sort of resonance (whether from the speaker or objects in the room, etc.), then the EQ will only be partially succesful, and once again, a balance between the meter reading will be called for in terms of transients versus a more steady signal.
The best thing to do is to take care of the room acoustics and speaker placement issues FIRST, and then see where you are. With decent speakers, many folks will find that once they do some of the things right in the first place, such as avoiding objects close to the front of the speakers, proper placement and toe-in, acoustic treatment at the right places of the right amount and composition, etc., then the need for an EQ is often greatly reduced.
Once you get to that point, the downside of EQ's, such as extra circuitry in the signal path, extra cables, extra potential for differences between the left and right channels, etc., become more of a liability than any small benefit that an EQ might actually provide.
Simple frequency response is NOT everything, you can EQ a Circuit Shack budget bargain speaker and receiver till you are blue in the face, and it will never sound like the real McCoy.
It was a popular option in the 70's-80's that has fallen out of favor but is now coming back in the digital domain in units like the Tact and DEXQ and analog with the Rives unit for room modes. I really depends on what you want to use it for. I can’t be used to correct in room on axis response anomalies caused by uneven power response in many speaker systems. I think that is one of the biggest pitfalls that many fall into. All you do is screw up the on axis response. How effective EQ can be has a lot to do with power response of the speakers and listening habits. If you listen near field the power response has much less influence on what you hear. If you listen far field then the system power response dominates. The combination of the two will influence how effective EQ will be. As far as response tailoring in speakers you need a good speaker design to begin with. You need good on axis and even power response to get the best chance of a good outcome but then only used as a last resort and with restraint.It can also not be used to correct gross room anomalies and if used for room correction is only effective as a cut only. You will get improvement as the peaks will be reduced but nulls are only correctable by placement. Any of the classic analog 1/3 octave room correction designs were cut only. That is really the best option as 6Db of boost will increase power demands by a factor of 4 and reduce your headroom accordingly. I have EQ’s in my main active set-up and they do help dial things in. They are cut only and the adjustments are only a couple of Db cuts in select bands. The changes with and without are subtle but for the better.
One of the biggest issues is setting the EQ up, You need some kind of measurement system to do it and once your happy with your house curve you lock it up and throw away the key. If you don't do that you will fall into the endless adjustment nightmare. This loop frustrates the hell out of people and many just give up. Also don't fall into the "I can do it by ear" camp either. If you don't use them now and never have you will be hopelessly lost especially using music to set-up. You use Pink Noise to get a general curve and then fine tune by ear with music. If you do go this way parametric gives the the most flexabillity just make sure you have some idea of what you are dealing with so you have enough bands available to get the job done.
not for any of the reasons stated in this thread. Records themselves often have problems with their frequency balance- too much bass or too bright being the most common in my experience- and this can be fixed with an EQ or tone controls. I have many recordings that are changed from rather unpleasant sounding to very nice by the application of EQ. In truth, something like a 16 or 32-band EQ is overkill for this and rather inconvenient in its detailed adjustment ability, and many/most preamps don't have tone controls these days for silly reasons.Using an EQ to adjust speaker response CAN help, but I find it to be tricky. Frequency response can vary significantly for small changes in a listener's position in most rooms, so there is no "right" setting. Small changes with an EQ are usually as far as one should go. Interestingly, my speakers have a built-in EQ for the bass, and the dealer adjusts it in your house for YOUR seating position to give a flat response down to 20 Hz. It does work for that one position, but of course there are other positions in the room where the response is not so flat; in my room that has been no problem.
I've tried the gamut of equalizers- analog and self-correcting digital. The results are similar- the room gets some correction, and if you pull the unit out, the stereo sounds better.Room treatment, speaker placement and choice of a good room :) seem to the the best options.
Equalizers generally have phase problems and noisy pots and transistors etc. They make it worse, plus they are generally too crude to solve the room problems.
I sold or tossed all mine and no longer use them.
BUT, it is probably too logical and factual for most. That's why they spend so much time buying / trading / selling gear so often. Rather than simply take the time to do their homework, get things right / as good as possible, they try to "band aid" the inferior products and installation that they thought would solve all their problems in the first place.One "fix" after another "fix" only gets them further addicted, a lot lighter in the wallet and nowhere near close to ending their frustrations. Maybe the next "fix" will solve all the problems. Maybe it won't have any drawbacks to add to the situation. Maybe one more piece will make up for the lack of planning in system building, the poor installation, the lack of attention to room acoustics, etc. Maybe, but probably not. Sean
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Frequemcy response is the most important aspect of audio and equalizers are great for reducing frequency response peaks from the room (under 100Hz.) ... or to make small corrections to the overall frequency response curve of the speakers.Most people try to do too much with their equalizers, or do not measure frequency response properly to set them, so the resulting sound quality is often worse than before.
Bass frequency response peaks caused by in-phase room reflections can make the fundamental tone of a bass note up to 6dB louder (100% louder subjectively) than the musician intended.
That means the music's bassline is significantly altered -- this is especially bad if a kick drum repeatedly excites a room bass resonance.
Parametric equalizers can eliminate bass peaks measured at one listening position, and are likely to improve the bass frequency response at seats close by.
More distant seats may sound worse.
Room corrections are very difficult above 100Hz. and not recommended:
- Small movements of the sound meter microphone will change the frequency response measurements and small movements of your ears will change the required EQ settings.Above 100Hz. you CAN make minor corrections to your speaker's frequency response as an alternative to new speakers. Buying new speakers is usually a better choice.
The corrections most likely to improve the sound of your speakers will be small (up to -3dB) cuts of frequency response peaks, based on my equalizer experiences since the early 1970's
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Examples:
(1) Reducing the midrange output of the speakers slightly if the speakers sound too "forward"(2) Reducing the treble output slightly if speakers sound too bright
The speaker corrections that work best are so minor that when you look across the room at the equalizer, it will be tough to tell that any of the controls have been moved at all. This is speaker "fine tuning" -- not room correction at all.
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Richard BassNut Greene
My Stereo is MUCH BETTER than Your Stereo
BWA HA Ha ha....After reading that line, i didn't bother reading any further. That's like picking one single aspect of a woman and saying that this physical trait is the most important out of everything that a woman can offer a man ( as far as "visuals" go ). It is no wonder you have such a simplistic view of audio reproduction and that "magic" is such a foreign word to your vocabulary. Sean
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... as I'm sure RBNG meant "a balanced and even frequency response" - also the tone of the post was unnecessarily aggressive.There is also a semantic difference between an aspect being "most important" and being the "sole criteria"...
So, chill...
Blind tests, e.g. by Dr. Floyd Toole, have demonstrated that frequency response is indeed the most important factor, and that trained and untrained listeners prefer speakers with flatter response, especially through the mid range.My own, personal, subjective experience agrees, though there are indeed other important aspects of speaker performance.
Nowhere in Richard's statement did he clarify that comment pertaining only to speakers. As such, the logical conclusion is that he was talking about system-wide performance.Personally, i am very much on the side of quantifying the qualities that we hear i.e. i do believe that how things perform electrically has a lot to do with what we hear. I believe that spec's can tell us a LOT of what is going on, when those spec's are derived on legit testing standards and properly interpreted. Most tests are rather limited in scope. With that in mind, most people don't know how to properly interpret the limited info that they are presented with. This is why most think that "spec's don't matter and have little correlation to what we hear sonically".
Having said that, i would rather have a system that was NOT "flat" in frequency response that sounded "musical" than a system that was "flat" yet sounded "cold, hard & clinical". I think that you'll find MASS MULTITUDES that would agree with this.
The perfect example of this is the fact that you have tons of "audiophiles" combining the "ruler flat" frequency response of "digital" with the "horribly non-linear" multi-fold distortions of high output impedance tubed componentry. If all that was important for digital to sound "good" was flat frequency response, it should be all that one could ever hope for. Obviously, there are TONS of other things that come into play, otherwise people wouldn't be willing to knowingly introduce measurable distortions into the equation to try and "fix" the problem ( that obviously DOES exist ). Sean
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"frequency response that sounded "musical" than a system that was "flat" yet sounded "cold, hard & clinical"You think this sonic signature comes from a flat frequency response?? Look to system distortion and you will be closer to finding the answer.
that sounding "cold, hard & sterile" was a "side effect" of flat frequency response. In fact, i was inferring that flat amplitude response was but a small piece of the puzzle and that there MANY other pieces of the puzzle to worry about.As such, we're on the same side here, not opposite : ) Sean
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Perhaps there's a difference. Personally I'm in the latter category and perfer my sound a bit rolled off on the top end.
Thanks for the very thorough response. I had no idea it was so difficult to equalize > 100Hz frequencies, but it does make sense that it should be so.
Like Rick says, EQ can be used for speaker response correction. To avoid spurious room effects, I'd guess the speaker measurements will need to be taken at close range, (near-field).
This is an area that I'll admit to having an issue with...If a set of speakers has an anomalous response curve, one has two basic choices:
1) Correction
2) ReplacementI battle to accept the logic of spending upwards of $1,000 on a decent parametric equaliser to apply correction to a flawed set of speakers - I'd much rather sell the speakers, combine the $1,000.00 I would have spent on the equaliser with the proceeds of the sale, then go out and find a pair speakers that meet my requirements.
Maybe I'm too much of a cynic?
It's a least disputable that you need to spent > $1000 on an effective equalizer. Consider the Behringer DEQ2496 and a few other examples.But on top of that, another $1000 more or less isn't necessarily going to get you all that much speaker improvement -- certainly not an almost flat response.
Some rooms are just inherently flawed from an acoustic standpoint. (Think of Avery Fisher Hall in NYC which has battled acoustic issues since it opened in the 1960's.)Some rooms will have sonically bad resonances or drop outs no matter what speaker is placed in them. In those cases, EQ may be the best or perhaps even the only way to address the issue.
... of equaliser on the market....For any serious digital-only audiophile application, it is probably safe to say that only DSP-based parametric equalisers are likely to be of more benefit than harm (on balance).
As RBNG pointed out, where an equaliser can be used for subtle corrections to room-mode induced problems in the lower registers where the wave-lengths are longish, then fine.
Where the corrections need to be drastic, I'd seriously recommend surgery to the room.
Where the corrections lie in the mid to upper registers, then I'd say you have a larger problem that probably combines elements of room and elements of system-matching - here you probably need to look at both...
One of the regular posters here has been using a Z-Systems RDP-1 for quite some time - and to very good effect. The primary reason for his use of the RDP-1 is to correct lower register, room-induced problems. Listening to his system with the RDP-1 "active" and "inactive" clearly demonstrates what can be achieved.
The Bottom Line: Follow RBNG's advice and only consider an equaliser if:
1) Your problems are restricted to room-mode based LF
2) Your sources are all digital
3) You're prepared to spend the money necessary for a DSP-based unitIf not, consider "swopping" rooms and siting the audio set-up in a room better-suited.
One other factor in this equation is that you also generally want a way to measure the frequency response in the room. That requires a quality microphone and a spectrum frequency analyzer. While not necessarily expensive (some equalizers include a basic analyzer function) it is a bit more complicated than just including a piece of electronics in your system loop.So there is also a learning curve with the room analysis and interpretation plus lots of experimentation to find the settings that not only address the imbalance that shows in the spectrum but also actually improves the sound you hear.
Even people who tinker endlessly in other ways with their system (trying different wires, adding power conditioning, adding magic clocks, etc.) may not find the needed EQ experimentation fits with their world view of audio.
Or to rent for the duration of set-up?I guess I'd rather spend the cash on room treatments than on limited usage electronics.
Doesn't matter whether you buy or rent. I'm sure some dealers offer this service. Or, there is software that will run on a laptop.We're not necessarily talking a lot of money. The ECM8000 Berhinger calibration mike I bought was about $50 brand new and the Baudline real time analysis software I run on my Linux laptop computer is open source software (i.e., free.)
Even though I ultimately rejected the permanent insertion of a DEQ in my system, I am very happy I went through the process. I learned a lot about my system and how it interacts with my listening room. It was an invaluable experience.
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