View Full Version : thought- Can equalisation be used to make cheap gear sound more "fancy"
1200reasons
19-10-2017, 00:43
Bear with me after my butchered title.
I was thinking about the Richard Clark $10,000 amplifier challenge (http://tom-morrow-land.com/tests/ampchall/index.htm), which provides a $10,000 reward to anyone who can discern between any 2 amps, after equalisation has been applied (to either amp, of the challenger's choice) to match them.
This means that a Class D amp can be compared to a tube amp, as long as equalisation is applied to either amp (of the challenger's chosing) to make it sound like the other. No one has yet won. One conclusion that seems fair to reach then is that anyone can grab a cheap class D and an equaliser and with enough time make it sound like a tube amp, or the best mcintosh.
To take this a step further- why would this not work with other gear too? I'm a vinyl guy and obviously you can't equalise a cartridge to make it track better or minimise IGD, or even extract details tight from the groove , but I can't see why you couldn't take an at95e to equalise it to sound like a grado gold? It would certainly be inferior, but it would have that grado sweetness.
I suspect that a lot of high end amps sound the way that they do purely because the makers deliberately "equalise" them internally to sound the way it does. What's wrong with external equalisation if a high-end amp only sounds the way it does due to internal equalisation?
Quick edit: A common misconception I see elsewhere about this challenge is that it requires equalisation to be put on the better amp to dull it down to the standards of the lesser amp. That isn't the case. The equalisation can be applied to the lesser amp to bring it to the same response of the better amp. The challenger gets to pick which amp sees the EQ
RothwellAudio
19-10-2017, 09:01
"EQ" just changes the frequency response, but since amplifiers without tone controls have a flat frequency response anyway between 20Hz and 20kHz (within a fraction of a dB) I can't see how equalisation would be any use. Cartridges, loudspeakers, microphones etc. are a different matter and EQ is certainly useful at the recording stage but I can't see how it could be used to make two amplifiers sound the same. They sound the same anyway according to Richard Clark.
1200reasons
19-10-2017, 09:28
Richard's test does not require that the 2 amps both be brought to a flat frequency response, but purely that one of the amps must be EQ'd to be the same as the other. Amp A might sound delightful, but not flat (because that its 'voice'). Amp B may be flat, but the challenger can choose to EQ Amp B to make it just as non-flat as Amp A. Rather than having 2 flat amps, we're left with 2 equally wonky amps.
What I'm proposing Andrew is the idea that a regular cheap amp which has a flat frequency response out of the factory could be voiced to remove the flat frequency, and give it the sound signature of a more "fancy" amp. No doubt someone has taken richard's test and brought in a 300B to compare to a class D. If so, why would I ever want to buy a 300B when I could just EQ a class D to make it the same?
RothwellAudio
19-10-2017, 11:16
Amp A might sound delightful, but not flat (because that its 'voice'). Amp B may be flat, but the challenger can choose to EQ Amp B to make it just as non-flat as Amp A. Rather than having 2 flat amps, we're left with 2 equally wonky amps.
Yes, but amps are not "voiced" as such and they all have a flat a frequency response. Any audible differences are due to much more subtle and complex causes such as the linearity at low levels compared to the linearity at higher levels, or the way the output interacts with reactive loads, or any number of other things which do not show up as a non-flat frequency response and cannot be mimicked or mirrored by EQ.
Amps can be voiced but that cannot be replicated with EQ - Clark was using EQ to compensate for valve amps rolling off early (i.e before 20khz), in other words, correcting frequency response differences.
I think the answer to the o/p is 'No'.
amps that have similar freq responses and good psu's and are fairly noise free should sound pretty much the same:sofa:
walpurgis
19-10-2017, 11:40
Clark was using EQ to compensate for valve amps rolling off early (i.e before 20khz)
What valve amps? Many have very extended HF response.
What valve amps? Many have very extended HF response.
Some valve amps - also as valve amps use output transformers their frequency response will vary with the impedance they see, so with some speakers they will not be inputting a flat frequency response. Since the challenge allows you to use any speakers you want the eq necessary, otherwise with the right amp/speaker match it would be pretty easy to win it.
1200reasons
19-10-2017, 22:17
What we've covered so far from this thread has that amps cant be voiced, that amps are voiced. I've learned that all amps have a perfectly flat response- except those that don't (tube amps rolling off before 20khz)
If
differences are due to much more subtle and complex causes such as the linearity at low levels compared to the linearity at higher levels, or the way the output interacts with reactive loads, or any number of other things which do not show up as a non-flat frequency response and cannot be mimicked or mirrored by EQ.
then why hasn't anyone claimed the $10,000? We say "the differences are.....", but then no one has actually sat down and identified any audible differences (in the at least 13 years of the challenge)
I find it a bit hard to believe that Head of Marketing has never said to Audio Engineer "We'd like to put this as the prestige model in our platnium series. Could you make it sound more warm and lush?", to which he's gone away and added some resistors and capacitors to tweak the FR a bit to boost and attenuate the desired areas
I'm not tryiing to be argumentative for the sake of it. Rather, I was considering that it may be an interesting idea. The prevailing opinion seems to be "it's not.". The easiest way to learn is to be wrong
fatmarley
20-10-2017, 03:06
It's very hard to hear differences with an unfamiliar system, unless they are quite large differences. Until I've lived with something for at least a week or two, I'd say I'm not 100% familiar with It's sound.
1200reasons
20-10-2017, 03:45
undoubtedly. If I was listening to an unfamiliar system when the speakers are changed I have no doubt I'd hear it. I'd expect 2 amps to be indistinguishable at first, but I'd damn well hope I could hear the difference between a solid state and tube
It would appear that in the 80s Bob carver challenged Stereophile that he could make one of his solid state amps sound like any amp of their choosing. They dutifully chose a valve amp that they felt would be the most dissimilar and difficult to emulate. On short notice, Carver had his (comparatively cheap) solid state sounding indistinguishable.
It is undeniable, however, that Bob had a lot more at his disposal than an EQ. The Stereophile article in question talks of him needing to match the harmonics etc, which is almost definitely not achievable with an EQ
I have a firstwatt and valve preamp that I've been squirreling away for quite some time. I may have to get my hands on a reference mic and EQ to experiment with this myself
then why hasn't anyone claimed the $10,000? We say "the differences are.....", but then no one has actually sat down and identified any audible differences (in the at least 13 years of the challenge)
I
The challenge seems to have been mainly in car audio. So no valve amps, no boutique exotica. And as he didn't keep records so it is hard to say what else went on. It isn't even clear if anyone did try a valve vs solid state challenge.
1200reasons
20-10-2017, 07:38
as he didn't keep records so it is hard to say what else went on. It isn't even clear if anyone did try a valve vs solid state challenge.
This is thoroughly annoying. It really decreases the value of the test when there's no data recorded. Bob carver managed to fool Stereophile, but without a solid background in amp making, I don't think I can expect to meaningfully replicate his results. At some stage in the future I'll get my hands on the gear to try this myself... but I suspect that I won't care by then. Just a fun idea to play around with
It's very hard to hear differences with an unfamiliar system, unless they are quite large differences. Until I've lived with something for at least a week or two, I'd say I'm not 100% familiar with It's sound.
Exactly. Sometimes I have left my system alone for months before making a change.
This is thoroughly annoying. It really decreases the value of the test when there's no data recorded. Bob carver managed to fool Stereophile, but without a solid background in amp making, I don't think I can expect to meaningfully replicate his results. At some stage in the future I'll get my hands on the gear to try this myself... but I suspect that I won't care by then. Just a fun idea to play around with
The Bob Carver thing was quite different. He set up a null test between his amp and the valve amp he had to emulate and then tweaked his amp until he could barely hear anything through the speaker, i.e the difference in output from both amps was next to nothing.
The listening tests to determine if he had succeeded were not done blind, and I've read that the mods Carver did to his amp to make this work meant it was no longer unconditionally stable and would not have lasted very long before it blew a gasket.
In short: no free lunches.
MrRadish
20-10-2017, 11:41
It costs $200 to take the test and you need to be on the East coast of the US, so that's me out. I'm not sure he's still doing them anyway.
A large proportion of the listeners were tested together (presumably in a large room) which would hardly be conducive to hearing differences. I don't think they paid the $200 though. The website does say headphones are allowed and I'm dead certain that identifying different headphone amps through my HD800 would be easy. I tried EQ once and it just clouded the sound. I wouldn't be so confident testing speaker amps in a large room.
I'm not sure quick-fire ABX works anyway. When I did sighted AB listening tests between analogue tuners and digital streams I couldn't tell the difference, yet I enjoy listening to the analogue tuners and quickly tune out (sorry!) when using internet radio. I can't tell you why as most of my music is digital and that's what I'm used to.
pgarrish
21-10-2017, 14:32
I suspect you can make an amp that matches speakers better sound like an amp that doesn’t using EQ, but you won’t fix a mismatch with EQ in my view.
Bob Carver made the claim that he could 'tune' or 'voice' his amplifier so that it would be indistinguishable from any chosen amplifier in a blind listening test.
I believe this challenge was tested by Stereophile magazine who chose the Mark Levinson ML-2 amplifier for Bob Carver to mimic. I don't know if the result was successful.
Talk of bob Carter.emulating other amps with one of his own throws up some interesting questions.
Chiefly, if all amps can be made to sound the same...why bother developing your own circuit at all?
Why not copy a reasonable design cheaply then increase costs to fleece customers?
My own experience go's only as far as attempting equalization of a pretty rough and bright sounding Sansui receiver from the late 70s
with a quite capable ADC 12 band graphic equaliser....with radical and refined settings of the sliders I was never fooled
into thinking the sound was anything better than cheap.
Nige.
Stratmangler
22-10-2017, 00:30
Talk of bob Carter.emulating other amps with one of his own throws up some interesting questions.
Chiefly, if all amps can be made to sound the same...why bother developing your own circuit at all?
Why not copy a reasonable design cheaply then increase costs to fleece customers?
My own experience go's only as far as attempting equalization of a pretty rough and bright sounding Sansui receiver from the late 70s
with a quite capable ADC 12 band graphic equaliser....with radical and refined settings of the sliders I was never fooled
into thinking the sound was anything better than cheap.
Nige.
Bob Carter lives next door but one to me. Honestly!
Do you mean Bob Carver?
The Bob Carver challenge thing sounds intriguing.
Make different amps sound alike with just EQ?
That's bollocks!
To make a SS amp sound like a valved amp requires a knowledge of how to emulate a transformer with a certain degree of signal saturation. The degree of saturation with the valve amp is totally dependent on the quality of the ironwork (ie transformer) and its laminations.
If you can emulate the performance of a valve amp with a certain degree of transformer saturation then you're some way towards achieving it, but by EQ?
Nah! That's fairytale bollocks and bullshit!
What does "go's" mean?
Do you mean "goes"?
1200reasons
22-10-2017, 04:22
Bob Carver made the claim that he could 'tune' or 'voice' his amplifier so that it would be indistinguishable from any chosen amplifier in a blind listening test.
I believe this challenge was tested by Stereophile magazine who chose the Mark Levinson ML-2 amplifier for Bob Carver to mimic. I don't know if the result was successful.
Nah, sterophile selected the Conrad-Johnson Premier Four, but did not reveal it for 24 years, because they didn't want to put themselves in a position of picking on any particular brand.
I think he only had 48 hours to do it. The challenge was successful
If you gave your EQ a midbass hump around a certain area, or slightly rolled off the treble then yes I do think EQ can make an amp sound like another amp. EQ may also be used to roll off the extreme bass to better suit a room / speaker interface.
I suppose it is worth mentioning that good amplifiers, used within their limits, should all sound pretty similar anyway. The only reason there are differences are that a lot of amps are not very good, or they are intentionally coloured, or they are run into clipping.
Nah, sterophile selected the Conrad-Johnson Premier Four, but did not reveal it for 24 years, because they didn't want to put themselves in a position of picking on any particular brand.
I think he only had 48 hours to do it. The challenge was successful
My mistake - it was the Audio Critic magazine who put up ML-2s for the Carver Challenge. https://www.stereophile.com/content/carver-challenge-responses
anthonyTD
22-10-2017, 14:58
That would be a very poorly designed Valve amp, well designed valve amps often have a higher frequency response than even the best solid state designs.
Its true that the output transformer can be the weakest link in the chain though, especialy at low frequencies. All conventional loudspeaker drive units have moving goal posts, where Frequency versus impedance is concerned. Therefore; both topologies of amp will put diffrent amounts of power into the changing speaker impedances, over the audio frequency range.
Amps can be voiced but that cannot be replicated with EQ - Clark was using EQ to compensate
for valve amps rolling off early (i.e before 20khz), in other words, correcting frequency response differences.
I think the answer to the o/p is 'No'.
Oh dear Mr stratmangler.....slight grammar errors due to spellchecker and you blow a fucking gasket.
Shame on you.
1200reasons
23-10-2017, 00:50
Somehow my morning coffee has completely failed to soak in- but I think Carver succeeded in emulating the Mark Levinson too. However, he did at one stage make the mistake of making his amp sound BETTER than the ML, so he had to turn down the performance of his amp.
If he's pulled it off twice (in 48 hours each), one must wonder what's achievable with more time but less genius
Stratmangler
23-10-2017, 07:48
Oh dear Mr stratmangler.....slight grammar errors due to spellchecker and you blow a fucking gasket.
Shame on you.
No I don't.
If your spell checker does that for you then you need to get a better one.
I asked for clarification, nothing more, and you blow a gasket.
Shame on you!
Touché
What I don't understand, in reference to spellcheckers (and predictive text), is no matter how good or bad they are, presumably YOU still get the chance to 'check' what's there, and make sure all is ok, before hitting the 'Submit Reply' button?
As they say, a poor workman always blames his tools! ;)
Marco.
True but they are a bit of a can't live with / can't live without feature in these days of soft mobile keyboards. Plain annoying either way.
What I don't understand, in reference to spellcheckers (and predictive text), is no matter how good or bad they are, presumably YOU still get the chance to 'check' what's there, and make sure all is ok, before hitting the 'Submit Reply' button?
As they say, a poor workman always blames his tools! ;)
Marco.
depends how well you spell, and how well you read
True but they are a bit of a can't live with / can't live without feature in these days of soft mobile keyboards. Plain annoying either way.
Sheer laziness - end of! ;)
Marco.
It became so obvious to me today at the bank that, whilst behind a disabled man being helped and it taking much time, and another man behind was grumbling, potentially we all potentially face that predicament, and that we also all have varied degrees of developmental support resulting in what we become.
The only time to chastise if at all, is when someone does not take an opportunity to do his best, or even worse cannot bother to try. I haven't got a degree and have spent years internally beating myself up about it, but my life was influenced by very negative feedback about my ability, and until 31 I thought I may really be thick because I had consistently been told so.
I think we must remember to be empathetic to others predicaments.
It became so obvious to me today at the bank that, whilst behind a disabled man being helped and it taking much time, and another man behind was grumbling, potentially we all potentially face that predicament, and that we also all have varied degrees of developmental support resulting in what we become.
The only time to chastise if at all, is when someone does not take an opportunity to do his best, or even worse cannot bother to try. I haven't got a degree and have spent years internally beating myself up about it, but my life was influenced by very negative feedback about my ability, and until 31 I thought I may really be thick because I had consistently been told so.
I think we must remember to be empathetic to others predicaments.
Indeed. to try your best is all anyone can do. failure should then not be an issue. No doubt many dont try very hard, but many, maybe most with disabilities do try hard, and often succeed to a level. It is all about levels though,as all have different ones.
depends how well you spell, and how well you read
Yup, but doesn't really apply with predictive text. If your phone (or whatever) has substituted an incorrect word and/or some gobbledygook, instead of what you'd intended to put, then it's up to you to CHECK it before it gets sent! ;)
As I've said many times before, all this sort of bollocks does is encourage lazy thinking, and our need to use our brains less and less - with unfortunate circumstances... I'm just dead against all the 'dumbing down' that exists today, in terms of how we communicate.
Marco.
sq225917
23-10-2017, 19:11
Chill out boys. i spend half the day spell checking and copywriting. I love posting on forums and I never check my typing, time off innit. It doesn't matter.
A question regarding the original post. I can see how EQ can be applied to an amp to get a similar frequency response to another amp, but what about output impedance and damping factor. You'd have to rematch those every time you tried it with different speakers, surely? (Assuming a none 0 sub miliohm output impedance) Seems like a big faff, unless you have fallen in love with a pissed FR.
paulf-2007
25-10-2017, 17:03
I turned off the predictive text on my iPad but it still types wtf it wants, I do try to make sure it's correct but often miss errors. I am a bit ocd on grammar and spelling. God knows what the future holds for the English language as even high flying ad firms are shit when it comes to grammar.
paulf-2007
25-10-2017, 17:19
Talk of bob Carter.emulating other amps with one of his own throws up some interesting questions.
Chiefly, if all amps can be made to sound the same...why bother developing your own circuit at all?
Why not copy a reasonable design cheaply then increase costs to fleece customers?
Nige.isnt that what happens already?
montesquieu
25-10-2017, 18:02
I suppose it is worth mentioning that good amplifiers, used within their limits, should all sound pretty similar anyway. The only reason there are differences are that a lot of amps are not very good, or they are intentionally coloured, or they are run into clipping.
Back on topic .. lot of sense in this but the amp is only half the equation. It's all about the amp and speaker combination - the same amp will sound utterly different to into cuddly old 16 ohm vintage speakers than it will into a set of 4 ohm Isobariks, 100 db sensitive full range horns or large electrostatics; conversely any given amp will make each of these speakers sound somewhere on the spectrum between superb and broken, depending on how much of a match it is for what those individual speakers require. I can hardly think of an amp that would give its best in all circumstances.
Hence all generalisations about amps = (ultimately) bollocks ... if I may make a bit of a generalisation ...
Back on topic .. lot of sense in this but the amp is only half the equation. It's all about the amp and speaker combination - the same amp will sound utterly different to into cuddly old 16 ohm vintage speakers than it will into a set of 4 ohm Isobariks, 100 db sensitive full range horns or large electrostatics; conversely any given amp will make each of these speakers sound somewhere on the spectrum between superb and broken, depending on how much of a match it is for what those individual speakers require. I can hardly think of an amp that would give its best in all circumstances.
Hence all generalisations about amps = (ultimately) bollocks ... if I may make a bit of a generalisation ...
I was taking it as read that you match the amp to the speakers.
montesquieu
25-10-2017, 21:56
I was taking it as read that you match the amp to the speakers.
I assumed you were .. compare one amp well-matched to a pair of speakers with another one, also well matched, and they should sound pretty much the same. I assume that's also what Peter Walker meant in his famous pronouncement.
But the argument does tend to get carried off in silly directions by people comparing apples with cheese. Discussing amps without also discussing the speakers they work with is a bit of a waste of time.
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