toddv (03/30/83)
Concerning the DAK ad for BSR equalizers: I saw one here in Portland (actually
I saw about ten stacked up on display) for 39.95 dollars.
Come to your own conclusions.
I recently purchased an Audio Source equalizer with a pink noise generator
and real time graphic equalizer for 250 dollars (probably 50 dollars too much).
An equalizer without the above enhancements is little more than a toy.
Even with the noise generator and analyzer, the improved quality of the sound
doesn't necessarily justify the price. Equalized sound resembles the sound
of an AM radio (it's very BRIGHT).
However, you can record the pink noise and play it back to the analyzer to
find which brand of tape gives the best response on your deck. You will
also notice that the quality of the high end of your system isn't terribly
important as very little music actually extends into those ranges around 20 kHz.
Very little even falls into the 16 kHz range.
(If you question this play alot of music and watch an analyzer display.)
Hope this helped,
Todd Vierheller
UUCP: ...!{ucbvax or decvax}!teklabs!tekmdp!toddv (ignore return address)
CSNET: tekmdp!toddv @ tektronix
ARPA: tekmdp!toddv.tektronix @ rand-relayfiled01 (04/01/83)
If the equalizer is used to make the room acoustic response perfectly flat, the sound will certainly be too bright. In a concert hall filled with people, there is a lot of absorbtion at the high frequencies by the time the sound gets to your ears. Only the recording mikes get all the direct unattenuated flat sound. After equalizing your listening room reduce the 8 kHz and 16 kHz about 4 and 8 dB respectively.That should make the result more pleasing. Herman Silbiger Certified Golden Ear
kar (04/02/83)
Re: "Equalized music sounds very much like AM radio: very bright." I once watched a friend "equalize" his stereo. He had brought home a back-seat-full of equipment, including an oscillator that generated sweeps from 0 Hz to 20 KHz, and a scope whose horizontal sweep was synchronized to the frequency produced by the oscillator. What resulted on the scope was a frequency-vs-amplitude plot, refreshed once each second. Anyway, he set up a calibrated microphone at his normal listening position and started the gizmo up. The scope showed loss of amplitude at the high end, but, interestingly, wide variation (+/- 10 dB) in the high end. In trying to correct this, he diddled with his equalizer, which brightened up the sound to an unplesant level. Is it possible that the single mike was sitting at a trough in the standing wave produced by the two speakers? Trying to "correct" the mike's low output by increasing the highs would explain why "equalized" music sounds so bad. Since moving the mike would only leave it in the trough of a different set of frequencies, I speculate that two are needed.
bill (04/04/83)
Microphones often used for concert-hall recording have a RISING high frequency response, to offset the roll-off caused by hall characteristics. The AKG modular condensor 400 series has two different [interchangable] capsules so you can do either close or distant mic-ing. bill cox bill@uwisc ..seismo!uwvax!bill
saf (04/05/83)
It is almost essential to use narrowband noise when equalizing a room. As has been pointed out, using sine waves shows up every peak and valley caused by standing waves. Two mikes won't solve anything because you can't find a representitive frequency anyway. If you use 1/3 octave pink noise centered on the frequencies of the equalizer, things will automatically start averaging out and the results will be more predictable and enjoyable. Note that where you sit is still important because (most) music isn't pure noise. In fact, listening to a pure tone or sustained note while moving your head will show severe amplitude changes. Since equipment to generate pink noise is very expensive some equalizers have the feature of using the filters from the equalizer to shape the noise. If you don't have that feature, use a test record - you'll be surprised how well it will work. Steve Falco BTL WH
rh@mit-eddie.UUCP (Randy Haskins) (08/12/83)
Well, I bought a(n) MXR 10-band a couple of years ago after hearing the effects on one a friend of mine bought. I'm not a real hard-core audiophile, but I do think that I have a fairly sensitive ear. I played with mine a little while after I first got it, then I just set it (boosting everything but 500 & 1K a little bit and dropping them about 3db; that's just what I like, I don't know why...) and don't really fiddle with it any more. On my amp, it gets hooked in on one of the tape-loops (I have 2). I've found that playing with the control switches allows you to pipe the output of the eq. into a feedback loop. Since you can adjust the gain to be >1, you can get oscillation (you can also play with the frequencies a lot). It's just something to try when you're really bored or messed up. -- Randwulf (Randy Haskins); Path= genrad!mit-eddie!rh or... rh@mit-ee (via mit-mc)
dbg@ihldt.UUCP (08/23/83)
I would guess that most people seldom change the settings of their equalizers. I believe I would not, and for this reason have never considered buying one. The one in my car has been changed almost not at all since I found my favorite settings. Also, remember that they represent just one more distortion introducing link in the chain. One thing I've found useful for altering frequency response according to need is the dolby switch on my tapedeck. Often when the listening area fills with (high frequency absorbing) people, I will switch out the play- back dolby correction to boost the highs a bit. ihldt!dbg
mat@hou5e.UUCP (M Terribile) (08/24/83)
I have heard that equilizers are noisy; that they cannot equal good quality pre-amps for low noise and distortion, etc. Can anyone refute this or offer counterexamples? Would anyone care to offer recommendations of favored makes? Mark Terribile
newman@utcsrgv.UUCP (Ken Newman) (08/25/83)
I've heard good things about the purity and low noise of the Hafler equalizer.
zzz@mit-eddie.UUCP (Mike Konopik) (08/25/83)
I've been exceptionally pleased with the performance of my Vector Research
VQ100 equalizer. It has not produced any discernable distortion or noise, even
after having had a shelf's support fail, dumping the entire stereo onto it...
I may be ignorant and mistaken about the usefulness of equalizers, but I don't
think I've regretted the $200 this one cost.
-Mike
!genrad!mit-eddie!zzz (UUCP)
zzz%mit-oz@mit-mc (ARPA)dmmartindale@watcgl.UUCP (Dave Martindale) (08/25/83)
I have a Southwest Technical Products octave-band equalizer. It is quite noisy, and the overshoot on a square wave input is impressive. I believe that its basic problem is that it uses 5558 op amps, which are just dual 741's. They are neither fast nor quiet. The basic design puts a group of 9 paralleled bandpass filters within the feedback loop of another op amp; I believe this makes the circuit much more sensitive to slow op amps. However, for $100, I really can't complain too loudly; it makes a nice toy but it isn't suitable for continuous use. A friend has an equalizer (also built from a kit) which didn't cost much more, and behaves considerably better. The manufacturer may have been MXR, but I'm just guessing.
dce@tekecs.UUCP (David Elliott) (08/26/83)
I recently bought a Parasound EQf120 for $40. This a six band stereo equalizer with controls for EQ defeat, tape monitor, and tape record EQ. This equalizer adds no discernable noise to my system, but I'm sure that is because I use my ears, and not test equipment, to listen to my music. The system I have is NOT an already noisy system, so you can't say that I can't hear added noise because there is so much already (I have an NAD 7445 reciever, Technics SL-5 close-and-play, and Polychrome (Aurora Sound) 2000 speakers, and listen exclusively to British import albums of "new wave" music). I'm sure that if I bought audiophile records, I would notice the difference. I like my equalizer since it helps eliminate the dead spots in my apartment until I can afford another pair of speakers (when you get used to 4 speakers, one pair just doesn't seem to sound quite right). David
jj@rabbit.UUCP (08/28/83)
The company who co-merchandized the Southwest TEch Products equalizer was, if I remember right, BSR. It was indeed very inexpensive and about asd as one would expect. SWTPC was undoubtely the cheap power amp company of all time, even if their produsts weren't that good. This is quite unlike Hafler, who, unlike what is said on the net, puts out an amplifier that's much better than most so-called audiophile stuff that costs 10X as much. Is SWTPC still (groan?) in business?
prophet@umcp-cs.UUCP (04/21/84)
<>
I sent this query out several months ago, but apparently it never got out
because I did not get a single reply. My apologies if any of you have
seen this before.
I am interested in purchasing an equalizer for my stereo system. I would
prefer to keep the expenditure to $400.00 or less. I plan to use the
equalizer to help obtain a more flat response across the spectrum in my
far-from-perfect (accoustically poor) living room. I would also like to
be able to equalize signals as they are about to be recorded; such as
when trying to "improve" the sound of an older record when recording it.
The best choice I have found so far is the Soundcraftsmen DC2215. It
seems to have all the features I am looking for, but I have no experience
with Soundcraftsmen equipment. Does anyone out there own this equalizer,
or any other Soundcraftsmen equipment? I would appreciate any opinions
on Soundcraftsmen equipment.
Also, does anyone have any other recommendations for a good equalizer
that meets the above requirements? I was once told that a para-metric
equalizer might be a better choice, and I agree that they are more flex-
ible, but then decent para-metric equalizers cost considerably over $400.
Just for reference, my system consists of the following:
Mitsubishi DAR-15 Receiver
Bang & Olufsen 2404 turntable
Bang & Olufsen MMC-2 cartridge
Nakamichi LX-5 Cassette Deck
B&W DM-220 Loudspeakers.
Thanks in advance,
Dennis Gibbs
--
Call-Me: Dennis Gibbs, Univ. of Md. Comp. Sci. Center.
UUCP: {seismo,allegra,brl-bmd}!umcp-cs!prophet
CSNet: prophet@umcp-cs
ARPA: prophet.umcp-cs@CSNet-Relayron@brl-vgr.ARPA (Ron Natalie <ron>) (05/01/84)
<Si Hoc Legere...> I'm not sure of the model numbers but I used a soundscraftsman equalizer at the university for PA work. I have no complaints. And anything that can stand up to 6 years or so of being hauled around on campus and used for all kinds of things it probably wasn't designed for probably is as durable as you are ever going to need for home use. A frined of mine also has one of these and he has no complaints either. The neat thing about the Soundscraftsman (if this is the same model I'm thinking of) is that it is a preamp in itself. It has multiple inputs and a phono preamp so that you don't need to have a separate preamp. I personally have a ADC Soundshaper IImkII which I bought a few years back for about $250 and I have had no problem with it. The cute averaging LED meters which I thought was a worthless gimmick did actually turn out useful when I was trying to figure out why half the sound went away on a job we were doing. ADC is also sometimes marked BSR (they're the same company). As for parametric (why the hyphen?) equalizers. I used these on sound consoles for varying the individual inputs, but they would probably be a pain in the neck to use on the output like in a home system. Besides the little slide pots in the graphic eq look real snazzy in your system. Both ADC and Technics have sort of a combined parametric/graphic eqalizer. In each case it is essentially a graphic equalizer with a little know for shifting the center frequency around. I don't think I've seen one where you could vary the Q (narrowness) of the filter. Technics used to make (I don't know if they still do) a rather large single channel model that we used at the radio station. It was rather nice. They also make a smaller stereo one that was part of their discontinued flat line. The BSR one is just the top end of their line. -Ron
gt@hplvla.UUCP (05/16/84)
I also had an older model Soundcraftsman equalizer and considered
it a good piece of equipment for the price.
As for setting up an equalizer, does anybody know what is
available in the way of low cost (but good (you scoff?))
spectrum analyzers? A friend and I are about half done
designing and building our own but we can't seem to get
away from creeping featurism so we could use some kind
of reference point.
Thanks.
George Tatge
HP Loveland Instrument Div.
ihnp4!hpfcla!hplvla!gtwjm@lcuxc.UUCP (B. Mitchell) (02/10/85)
Personally, I agree with Dick Grantges. The ability of an equalizer to correct frequency response abberations in a room (and to second-guess the recording engineer) more than offsets the minor phase distortion and noise that a good EQ will add. A spectrum analyzer is essential to properly EQ a room without much hassle, and many of the better units combine an EQ with an analyzer. The key thing is to get a GOOD EQ, which will set you back $500+ (a cheapo one isn't worth the trouble). Regards, Bill Mitchell (ihnp4!lcuxc!wjm)
gvcormack@watdaisy.UUCP (Gordon V. Cormack) (07/17/85)
It is my impression that almost all differences between reasonable quality stereo components can be attributed to differences in frequency response across the audio spectrum. Therefore, I have decided that I should buy a multi-band equalizer. I would like to have answers to two questions: First, what makes and models are recommended and for what reasons? I am interested in at least 1-octave resolution; 1/2 octave would be better if it doesn't cost 10 db more. Second, I don't see how one could possibly calibrate the system by ear. It seems to me that one would want to measure the SPL generated by a known source. The source is (relatively) easy to come by; one can buy or build a tone generator. Once upon a time, I saw a test record with a number of tones on it as well. One can also build a SPL meter with a microphone and a volt meter, but that would measure the frequency response of the microphone more than anything else. Do there exist such meters at reasonable price? If so, where can they be obtained? Alternatively, if I had a known source, I could calibrate my own. Perhaps I am being unfair to calibration by ear. What are normal methods for setting up equalizers by ear? I do not regard listening to my favourite record and diddling it 'till it sounds good acceptable. I can't even do this with the 3 tone controls I have. I have tried from time to time and am sometimes happy for a while, but invariably am happier with them all in the "flat" position. -- Gordon V. Cormack CS Department, University of Waterloo gvcormack@watdaisy.uucp gvcormack%watdaisy@waterloo.csnet
herbie@watdcsu.UUCP (Herb Chong [DCS]) (07/20/85)
In article <7351@watdaisy.UUCP> gvcormack@watdaisy.UUCP (Gordon V. Cormack) writes: >It is my impression that almost all differences between reasonable >quality stereo components can be attributed to differences in >frequency response across the audio spectrum. Therefore, I have >decided that I should buy a multi-band equalizer. a controversial statement, but one of which i happen to believe to be true. >I would like to have answers to two questions: First, what makes and >models are recommended and for what reasons? I am interested in at >least 1-octave resolution; 1/2 octave would be better if it doesn't >cost 10 db more. a proper parametric equalizer is best, one with at least 4 or 5 bands per channel. failing that, a 1/3 octave equalizer is next best. since you want to stay with octave equalizers, the choice is fairly large. almost every major manufacturer has at least one. depending on the features you want, you can pay as little as $250 CAN or as much as $900 CAN for an octave equalizer. if you feel rich, you can get a Technics single channel 16 band parametric for $1900/channel. all kidding aside, i think that a decent equalizer can be had for about $400 CAN with useful features like an RTA and pink noise generator and microphone. >Second, I don't see how one could possibly calibrate the system by >ear. It seems to me that one would want to measure the SPL generated >by a known source. The source is (relatively) easy to come by; one >can buy or build a tone generator. Once upon a time, I saw a test >record with a number of tones on it as well. One can also build a >SPL meter with a microphone and a volt meter, but that would measure >the frequency response of the microphone more than anything else. >Do there exist such meters at reasonable price? If so, where can they >be obtained? Alternatively, if I had a known source, I could >calibrate my own. calibrated SPL meters sell for about $250 CAN. the Technics SH-8000 comes to mind. >Perhaps I am being unfair to calibration by ear. What are normal >methods for setting up equalizers by ear? I do not regard listening >to my favourite record and diddling it 'till it sounds good acceptable. >I can't even do this with the 3 tone controls I have. I have tried >from time to time and am sometimes happy for a while, but invariably >am happier with them all in the "flat" position. calibration by ear is notoriously unreliable. depending on what your ear was subject to in the few hours before the attempt, you could be wildly off or near perfect. Herb Chong... I'm user-friendly -- I don't byte, I nybble.... UUCP: {decvax|utzoo|ihnp4|allegra|clyde}!watmath!water!watdcsu!herbie CSNET: herbie%watdcsu@waterloo.csnet ARPA: herbie%watdcsu%waterloo.csnet@csnet-relay.arpa NETNORTH, BITNET, EARN: herbie@watdcs, herbie@watdcsu
rdp@teddy.UUCP (07/23/85)
In article <1545@watdcsu.UUCP> herbie@watdcsu.UUCP (Herb Chong [DCS]) writes: >In article <7351@watdaisy.UUCP> gvcormack@watdaisy.UUCP (Gordon V. Cormack) writes: >>It is my impression that almost all differences between reasonable >>quality stereo components can be attributed to differences in >>frequency response across the audio spectrum. Therefore, I have >>decided that I should buy a multi-band equalizer. > >a controversial statement, but one of which i happen to believe >to be true. > Yes indeed, a controversial statement, but it does not have a whole bunch going for it. Much of the coloration that we hear can be attributed to frequency response anomolies, but simple linear equalization is most often completely inadequate to the task. Take the problem of room resonanaces, something which people usually by equalizers to correct. You can measure errors in the steady-state frequency response and then equalize for these errors, and the steady state response might look better. But, what happens in such resonances (and those associated with speaker problems as well, such as cabinet resonances, cone resonances, etc.) usually result from long term energy storage and subsequent release at different ffrequencies. For example, there is the tale about the early days of computerized speaker analysis where there was a certain speaker which measured fine under steady state conditions, but people complained of it being very "brittle" or "sizzly". It was later discovered that after the driving signal had ceased, the speaker's output decayed normally until about 2 or 3 milliseconds after the cutoff, when it started singing away at 7 Khz for some 20 milliseconds!. An equalizer cannot in any way cope with this sort of anomoly. WHat equalizers are best for are taking care of mis-equalized records, poorly designed crossover networks, slight errors in RIAA phono equalization and so forth. WIth the exception of the first, these items aren't the province of an equalizer to correct, they should have been done correctly to begin with. In short, my advice to the vast majority of equalizer customers is: save your money, and use it to upgrade other components that are at fault. Solving one frequency response error with another is non-productive. Dick Pierce
klein@ucbcad.UUCP (Mike Klein) (07/23/85)
> It is my impression that almost all differences between reasonable > quality stereo components can be attributed to differences in > frequency response across the audio spectrum. ********* ARRGHH!!!! ****************** -- -Mike Klein ...!ucbvax!ucbmerlin:klein (UUCP) klein%ucbmerlin@berkeley (ARPA)
nz@wucs.UUCP (Neal Ziring) (07/23/85)
In article <7351@watdaisy.UUCP>, gvcormack@watdaisy.UUCP writes: > It is my impression that almost all differences between reasonable > quality stereo components can be attributed to differences in > frequency response across the audio spectrum. Therefore, I have > decided that I should buy a multi-band equalizer. > > Second, I don't see how one could possibly calibrate the system by > ear. It seems to me that one would want to measure the SPL generated > by a known source. > Gordon V. Cormack CS Department, University of Waterloo I recently bought a BSR Q3000 (?) 10-band octave equalizer. It has a built-in pink-noise generator, octave spectrum analyzer, and comes with a (supposedly) calibrated microphone. Having a spectrum analyzer on the equalizer makes equalizing a room or a tape deck quite easy -- equalizing a room takes < 20 min. One thing to watch in calibration (and this is what makes it rather difficult) is that the slide controls on the equalizer do not effect only thier portion of the freqency band. As is typical in that kind of gain/attenuation circuitry, they affect frequencies further from their center frequency less, but moving the 500 Hz control will have some effect on a 125 Hz test tone. In my humble opinion, the addition of a fairly good equalizer has improved the sound of my system immensely, and the spectrum analyzer is a lot of fun to watch. -- ======== ...nz (ECL - we're here to provide superior computing) Washington University Engineering Computer Laboratory "Now we'll see some proper action..." old style: ... ihnp4!wucs!nz new style: nz@wucs.UUCP
fritz@phri.UUCP (Dave Fritzinger) (07/25/85)
> In article <7351@watdaisy.UUCP>, gvcormack@watdaisy.UUCP writes: > > It is my impression that almost all differences between reasonable > > quality stereo components can be attributed to differences in > > frequency response across the audio spectrum. Therefore, I have > > decided that I should buy a multi-band equalizer. > > In my humble opinion, the addition of a fairly good equalizer > has improved the sound of my system immensely, and the spectrum analyzer > is a lot of fun to watch. > -- > ======== > ...nz (ECL - we're here to provide superior computing) > Washington University Engineering Computer Laboratory > I would tend to disagree. In fact, I am of the opinion that even tone controls are not needed, and indeed, tend to degrade the sound quality. This was proven to me when I compared a really good amp without tone controls (in my case, an amp and preamp by Naim) with my old unit, which had tone controls. The result was that the good amp sounded much better. Obviously, many audio engineers agree with me-after all, why do so many good amps come with defeat switches for their tone controls? Also, when you look at REALLY expensive and esoteric amps (or preamps), they tend not to have tone controls (or other bells and whistles). -- Dave Fritzinger Public Health Research Institute NY,NY {allegra!phri!fritz} "Blasting, billowing, bursting forth with the power of 10 billion butterfly sneezes..." Moody Blues
fritz@phri.UUCP (Dave Fritzinger) (07/25/85)
> > It is my impression that almost all differences between reasonable > > quality stereo components can be attributed to differences in > > frequency response across the audio spectrum. > > ********* ARRGHH!!!! ****************** I agree with the above comment -- Dave Fritzinger Public Health Research Institute NY,NY {allegra!phri!fritz} "Blasting, billowing, bursting forth with the power of 10 billion butterfly sneezes..." Moody Blues
rfg@hound.UUCP (R.GRANTGES) (07/26/85)
[] Whoever started this is probably right, despite all the ad hominem arguments that have been advanced. In the published comparisons I have seen, it's aligning the frequency response that does the trick - after matching levels, of course. The latest such was the story of Carver's " t " series of amps. -- "It's the thought, if any, that counts!" Dick Grantges hound!rfg
sjc@angband.UUCP (Steve Correll) (07/26/85)
> It is my impression that almost all differences between reasonable > quality stereo components can be attributed to differences in > frequency response across the audio spectrum. Therefore, I have > decided that I should buy a multi-band equalizer. > Second, I don't see how one could possibly calibrate the system by > ear. It seems to me that one would want to measure the SPL generated > by a known source. The source is (relatively) easy to come by; one > can buy or build a tone generator. Once upon a time, I saw a test > record with a number of tones on it as well. One can also build a > SPL meter with a microphone and a volt meter, but that would measure > the frequency response of the microphone more than anything else. > Do there exist such meters at reasonable price? If so, where can they > be obtained? Alternatively, if I had a known source, I could > calibrate my own. Equalizers are controversial because they introduce phase shifts and small anomalies in the process of correcting for big ones, but I'll avoid taking a position on that topic. You're right that calibration by ear is dicey. Radio Shack used to sell a sound pressure level meter, but I can't find it in the latest catalog; you might ask your local store manager if it's still available. Supposedly pink noise is a better source than pure tones, since the latter may excite narrow-band room resonances and bias the results. You can build a pink noise generator plus multi-band equalizer for yourself from plans in the National Semiconductor Audio-Radio Handbook, about $10 (for information on buying it, call National at 408 737-5000). Stereo Review used to sell for less than $10 an audio test record called the SRT 14-A with a number useful signals, including 29 narrow bands of pink noise spanning the audio spectrum. I haven't seen an ad for it lately, but you might contact them for information: Stereo Review One Park Avenue New York, NY 10016 (212) 503-4000 CBS labs also makes a number of test records, including "STR140: RIAA Pink Noise Acoustical Test Record", which used to be available (again, I haven't seen an ad lately) for $15 from: Old Colony Sound Lab PO Box 243 Peterborough, NH 03458 -- --Steve Correll sjc@s1-b.ARPA, ...!decvax!decwrl!mordor!sjc, or ...!ucbvax!dual!mordor!sjc
greg@olivee.UUCP (Greg Paley) (07/29/85)
> Dave Fritzinger > Public Health Research Institute > NY,NY > {allegra!phri!fritz} > ... > In fact, I am of the opinion that even tone > controls are not needed, and indeed, tend to degrade the sound quality. > This was proven to me when I compared a really good amp without tone > controls (in my case, an amp and preamp by Naim) with my old unit, which > had tone controls. The result was that the good amp sounded much better. > Although tone controls may degrade the sound quality when reproducing sonically perfect recordings, the sad fact is that a number of recordings are defectively equalized and require modification to make them enjoyable or, in some cases, even listenable. One could say that record companies should do this right in the first place, but that doesn't help the consumer who is stuck with what is actually available. Prime examples of this are classical reissues, most notable many of the London "Stereo Treasury" series and various RCA reissues of Toscanini material. In an apparent effort to make these old recordings sound more "hi-fi" the remastering engineers have boosted the treble and reduced the bass to a degree that drastic compensation is necessary to restore a reasonable tonal balance. Those who are more interested in sound per se than music would argue "why buy those recordings then?", but for me, at least, there are a number of cases where these recordings provide the only examples I've heard in which the musical shape and form, as specified by the composer in the score, emerges in sound. Therefore, I refuse to give up the superior musical satisfaction of the older recording. On the other hand, I refuse to live with the falsifications a remastering engineer has wrought on the original sound. Ergo, I need tone controls. - Greg Paley
wilson@convex.UUCP (08/09/85)
If differences in signals between two systems are not evident in their
frequency responses then somebody had better publish that quick !
EE departments throughout the world are teaching students otherwise
when they introduce the poor unsuspecting people to Fourier transforms.
Seriously though, an (analog) equalizer doesn't exist which could be used
to correct anything other than gross disturbances in the system's
frequency response. My system has and has always had such disturbances
(they vaired from dwelling to dwelling, though) and I've used an octave
wide Soundcraftsmen equalizer for years. In my case, it's been better
than nothing (my speakers seem to have a nasty peak around 7000 Hz no
matter what kind of room they're in) but I've convinced myself that a
1/3 octave equalizer would be far superior. These are not at all cheap
though, and I could probably replace my speakers and solve the problem
that way for a little more money.
My Soundcraftsmen eq. came with a record that has bands of octave centered
pink noise on each channel at a time, with an (optional if you have a meter)
Fletcher-Munsen weighted reference signal in the opposite channel.
In actual use, the "flat" eq. setting arrived at through iterations of the
test record was fine for a starting point, but often slightly changed for
individual source material. Some source is best with the eq. out of the
loop entirely.
{ihnp4,allegra,uiucdcs,ctvax}!convex!wilsonnorman@lasspvax.UUCP (Norman Ramsey) (08/13/85)
In article <32900018@convex> wilson@convex.UUCP writes: > >If differences in signals between two systems are not evident in their >frequency responses then somebody had better publish that quick ! >EE departments throughout the world are teaching students otherwise >when they introduce the poor unsuspecting people to Fourier transforms. The differences are evident only when the *complex valued* frequency response is given (magnitude and phase). I have never seen any phase information on any audio equipment. I would like to. -- Norman Ramsey ARPA: norman@lasspvax -- or -- norman%lasspvax@cu-arpa.cs.cornell.edu UUCP: {ihnp4,allegra,...}!cornell!lasspvax!norman BITNET: (in desperation only) ZSYJARTJ at CORNELLA US Mail: Dept Physics, Clark Hall, Cornell University, Ithaca, New York 14853 Telephone: (607)-256-3944 (work) (607)-272-7750 (home) Never eat anything with a shelf life of more than ten years
herbie@watdcsu.UUCP (Herb Chong - DCS) (08/18/85)
>Gordon Cormack writes: >It is my impression that almost all differences between reasonable >quality stereo components can be attributed to differences in >frequency response across the audio spectrum. Therefore, I have >decided that I should buy a multi-band equalizer. >I write: >A controversial statement, but one that i happen to believe to be true. >Dick Pierce writes: >Yes indeed, a controversial statement, but it does not have a whole bunch >going for it. Much of the coloration that we hear can be attributed to >frequency response anomolies, but simple linear equalization is most often >completely inadequate to the task. i did not mean to imply that an equalizer was a panacea for all evils. there are, however, enough problems that can be solved by a good equalizer that it is worth it. if you would have included the rest of my article, i point out that only a parametric equalizer would really be worth getting for this type of work. i myself do not own an equalizer yet because i can't afford the kind that's worth getting. >Take the problem of room resonanaces, something which people usually by >equalizers to correct. You can measure errors in the steady-state frequency >response and then equalize for these errors, and the steady state response >might look better. But, what happens in such resonances (and those associated >with speaker problems as well, such as cabinet resonances, cone resonances, >etc.) usually result from long term energy storage and subsequent release >at different frequencies. what most people should be correcting with equalizers is not room resonance but reinforcement and cancellations by reflected sound waves at different frequencies. resonances in the reproduction system after the point where equalization is applied cannot be corrected for easily because the system is unstable at that frequency. also, as you point out later, misequalized recordings are another key area to address using an equalizer. those problems alone are serious enough that if one is very fussy about the music they listen to, then it's worth doing something about. an ordinary multiband equalizer is usually not up to the job. a good parametric with at least 5 bands per channel is required. >Dave Fritzinger writes: >I would tend to disagree. In fact, I am of the opinion that even tone >controls are not needed, and indeed, tend to degrade the sound quality. >This was proven to me when I compared a really good amp without tone >controls (in my case, an amp and preamp by Naim) with my old unit, which >had tone controls. The result was that the good amp sounded much better. >Obviously, many audio engineers agree with me-after all, why do so many >good amps come with defeat switches for their tone controls? Also, when >you look at REALLY expensive and esoteric amps (or preamps), they tend not >to have tone controls (or other bells and whistles). this is a statement which compares apples and oranges. i could have said "my Porsche 928 is better than your Volkswagon Beetle because i have a turbo in my 928" and have been just as meaningful. if you had compared a really good preamp with tone controls to a really good preamp without tone controls, i would have not saved away this article for comment. ANY tone control degrades the signal as it passes through, not matter how good the components. the name of the game is to make the degradation as small as possible. as for the defeat switches, it depends on the price point why they're there. at lower prices, i think it's to emulate the higher priced models in image. in the higher prices, it's because often the rest of the equipment and the material being reproduced is good enough that no frequency modification is required. if you don't need any change, then why not remove the circuit from the signal path, even if the improvement in signal is nearly non-existent. it can't hurt any. but if you do need them, then they are there. the companies that make preamps without any tone controls at all fall into two main camps: ones that believe that the systems their equipment will go into will be so good that no modification of the signal is necessaryor desired, and those that believe that mere tone controls are hopelessly inadequate and that anyone wanting to modify the frequency response of their system would do it right and use a good equalizer. Herb Chong... I'm user-friendly -- I don't byte, I nybble.... UUCP: {decvax|utzoo|ihnp4|allegra|clyde}!watmath!water!watdcsu!herbie CSNET: herbie%watdcsu@waterloo.csnet ARPA: herbie%watdcsu%waterloo.csnet@csnet-relay.arpa NETNORTH, BITNET, EARN: herbie@watdcs, herbie@watdcsu