Audio Blind Testing

[sandyk]

8 minutes ago, gmgraves said:

Many would include ABX testing in this, but I don't simply because nobody has been able to ever convince me that the ABX comparator doesn't color the results. The only way is to manually swap out those devices under test.

  I agree.

The only way is to have somebody else not connected with the listening decisions part, to manually swap out the devices under test behind the scenes.

[sandyk]

1 hour ago, fas42 said:

Things like interconnect cable differences will always fail in DBT - that's because the time factor aspect is never part of the test -

 The time factor is very relevant due to the length of time between cable changeovers.

 The problem here, is that even  if you switch using a relay type comparator, you are introducing other variables such as plugs and sockets and additional length compared with using just the cables themselves. 

[sandyk]

33 minutes ago, gmgraves said:

You're right. Interconnect differences will always fail a DBT because they don't exist.

 George

 I thought that you had got well past these dogmatic assertions  about Interconnects, but apparently not.

Interconnects of the same length , but of different construction can sound quite different due to differences in capacitance, immunity to RF/EMI  etc. A Blue Jeans LC1 for example , with just over half the capacitance of many other interconnects can sound quite different to a typical coaxial construction type cable of the same length due to interactions with the output stage of the DAC, Preamp etc.  Many commonly used I.C.s used in consumer gear output stages do not like driving higher capacitance loads, and can even become unstable when driving higher than average cable capacitance and often use series output resistors of typically 100 ohms to help prevent this.

The LM4562 for example, is quite fussy in this respect.

Alex

 

P.S.

This is starting to sound a bit like Groundhog Day !

[sandyk]

Quote

Alex, I just looked up LC1 cable. For a 6ft length LC1 has capacitance of 73pF, resistance of 0.204Ω . In comparison, a 25ga zip cord of the same length has 96pF C and 0.3Ω R. If this is enough to cause a problem with an output stage designed for audio frequencies, then I'm afraid it's just not designed well at all!

 

And here are the filtering characteristics of  a 6ft LC1 cable over 10-30,000Hz range:

 

 

 

 

And here's one of a 6ft, 25ga zip cord:

 

 

If you think you can hear the difference of under 1/1,000,000,000 of a dB at 30KHz, I'd be extremely impressed!!! 

 

 

For starters, nobody in their right mind would use a Zip cord for an Interconnect !!!

 

I was talking about coaxial type cables as commonly used for Audio interconnects.

Some time back I purchased 2 6ft.Blue Jeans cables for use connecting my DAC to the Preamp at the other side of a wide wooden Entertainment centre with Perspex doors and equipment shelves.

I found that the Blue Jeans LC1 cables made drums sound a little too metallic, and reverted back to the DIY cables as described below.  I gave the Blue Jeans cables to a friend.

 

The attached is from a Jaycar WB1508 cable that I have used for making high quality interconnects with good quality metal RCA plugs. :

High quality OFC mono audio cable, double screened for extra shielding. Ideal for making your own RCA leads etc.
- Conductor Material: OFC
- Insulation Material: PPE
- Stranding: 45/0.12mm
- Braid Stranding: 96/0.10 + Alum
- Conductor Resistance: 0.0365ohms/M
- Capacitance: 66.8pf/1M
- Impedance: 65ohms@1m
 

Before you jump down my throat and tell me that drums are LF and the cables can't possibly have any effect, have a look at the attached below which shows the VERY fast rise times of the envelope.

Click on the image for a larger image.

P.S.

 You would be surprised to see what small differences many members are capable of hearing, even the effects of improved screening on a couple of feet of D.C. cable !

Check out the Uptone area of the forum - DIY DC Cables, and an improved design by E.E. John Swenson. 

 

Yim Hoh_Man_Poem of Chinese Drum

[sandyk]

4 minutes ago, esldude said:

Nope, ipad spectrum analyzer won't cut it.  If you don't care, I don't either. 

 

I'll reiterate ," Without at least those two conditions being met, two files sounded different for reasons unknown."

 

You'll, like many others feel edified.  And that is about all your methodology is worth.  If that is good enough, then fine.  Simply means not much of anything.   

Dennis

 Given that the normal CD spectrum  area of both files is likely to be the same,(?)  why should it matter, especially as you have stated on numerous occasions that anything higher than 16/44.1 is a waste of time and that high res audio can't be statistically verified as being worthwhile .

Your long standing stance in this area disqualifies you from making a legitimate judgement on MQA sound quality, which can NEVER be better than the original high definition music file that it was sourced from anyway, so why offer MQA as an alternative other than for sinister DRM purposes ? 

Perhaps the Industry regrets making high res files available from HD Tracks etc. ?

Alex

[sandyk]

10 minutes ago, fas42 said:

Your claim is that differences in cable materials, construction, how it is connected into the circuit is always inaudible - many who have investigated this as an experimental exercise, as compared with doing a quick switcheroo to confirm a prejudged notion, have found otherwise.

 

 When Marc gets his act together, he really should try a decent low noise Linear PSU for his antiquated (In SQ terms) beloved SBT ! He may then start to get a bit more adventurous and discover that his theoretical based dogmatic assertions on what is, and isn't audible, aren't always correct, as it's resolving abilities further improve.

I don't doubt that Marc is a whiz in the area he works in, but you can't always directly transfer all of this to other fields such as Audio, or even Digital Video for that matter, which also includes Audio.

[sandyk]

19 minutes ago, fas42 said:

 

Ummm, bits of wire lying around is good enough, most times - if used well. Current experimental rig, NAD components, uses a bit of a single twisted pair, solid strand Cat cable between source and amplifier - works well enough to make all the other weaknesses which are holding back the sound obvious. Perhaps it will be worth making that connection "better" down the track, perhaps not ...

 

  But you live in an area (lower Blue Mountains ?) which is well removed from the industrial areas of Sydney, and the vast majority of high powered AM, FM Stereo, DTV and Radar transmitters.(Weather and Aviation etc.)

There is a big difference between a Zip cable and a twisted pair which has been used since the evolution of Telecommunications to improve signal integrity.

[sandyk]

4 minutes ago, knickerhawk said:

And it’s not simply that the “two files sound different for reasons unknown.” What I’ve learned is that there is a general “signature” to the MQA sound. I’ve learned that the signature I’m detecting is not attributable to subject bias (thanks to the blinded testing I’ve now conducted). Likewise, I’ve learned that my personal preference for that identifiable sound is not attributable to subject bias. That certainly doesn’t mean much for others’ preferences, other listening setups, etc., but it means quite a lot for my own personal listening enjoyment. 

 The only way to put this to rest is to directly compare the original High Res recording (not a copy of a copy, of a copy  of the original etc.) against the decoded MQA version, however the record companies are highly unlikely to let that happen. They want their DRM and control back again.

 I think it's more likely about Piracy control issues why they are interested in MQA, just like the LF watermarks they tried in some DVD-As and Sony tried with some CDs to prevent copying.(Sony Rootkit)

[sandyk]

42 minutes ago, gmgraves said:

don't want to start this again, but with your knowledge of electronics, I'm sure you know that differences in capacitances, Inductances etc.; while they can have an effect at very high (essentially RF) frequencies, don't affect audio frequencies at all except in very long runs of 50 ft or more. (where RG 59U is down 1 dB at 20 KHz, IIRC)

 George

Based on my personal experiences with the music track of the .wav file waveform that I attached, I do NOT agree with you, and neither do a large number of members agree with you about the audible differences between different Interconnects.

There is obviously far more to it than just Attenuation with Frequency, there is also rejection of RF/EMI etc. and the resistivity of the Earth side in  particular does matter when it is part of the reference Earth for the system.

Neither can I explain the audible differences that I hear between 2 75 ohm 1.5M cables that I use for Coax SPDIF.

Recently, one of the RCA plugs became a little loose in the socket of my Soundcard, so I replaced it. What did surprise me was that unlike many, it had 2 layers of braiding as well as aluminium foil, and immediately struck me as better made.

 Did you see my comment about short D.C.  cables discussed in the Uptone area of the forum where E.E. John Swenson describes a technical and audible improvement for even short D.C. cables ?

 These guys are hearing confirmed differences that I wouldn't have believed possible either.

 Previously, like you, I thought that most of this discussion about differences between cable was due to a placebo effect.

 I said as much in the Uptone area about the short D.C. cables, but John  quickly shot me down with technical explanations which also included RF/EMI emitted FROM the D.C. cable itself when used with some Digital devices due to the very sudden current demands involved.

Alex

[sandyk]

1 minute ago, pkane2001 said:

Sure, but if a zip cord has nearly the same LRC characteristics as LC1, then what accounts for the difference?

 

 I have already answered some of these things in my reply to George.

A Zip cord for example has very little RF/EMI rejection.

 

 Nothing , myself or others are likely to say on this subject is ever going to change either George's or your minds.

I am simply reporting my observations, and I am only one of a large number of members who report hearing similar differences.

Just because you are unable to hear the differences that John and others have reported, doesn't mean that they don't exist.

If you have been closely following the thread, you will have noticed that I also found the reports a little unbelievable, especially as I use D.C. cables of no more than 2 feet long salvaged from redundant 2 pin mains leads. In other words , fairly heavy duty wire. However, if John Swenson reports these things and others verify them independently, I will bow to his superior knowledge of the subject. I have since obtained 2M of the cable described, and will eventually try this for myself, despite my reservations.

 

http://www.ebay.com.au/itm/2M-Canare-L-4E6S-Premium-Balanced-Quad-XLR-Microphone-Cable-Made-in-Japan/261917497557?ssPageName=STRK%3AMEBIDX%3AIT&_trksid=p2057872.m2749.l2649

[sandyk]

1 minute ago, gmgraves said:

I believe in buying quality cables, and I do. But that's construction quality, not SQ. 

 That was exactly the case with this Coax SPDIF cable. It was a more expensive replacement for an older cable that had become poor fitting due to being moved around numerous times over the years, with PC moves to different addresses and PC upgrades.

 I certainly did NOT expect to hear any difference between functioning Coax SPDIF cable of a similar length, any more than I expected to hear a difference between a proper INSULATED 75 ohm BNC socket on my DAC and a generic, less well constructed 50 ohm version which people like yourself claim can't possibly make any difference in such a short length.

[sandyk]

3 minutes ago, gmgraves said:

 

What if RF/EMI isn't a problem in one's specific situation? A guy I once knew made up a pair of "interconnects" using 12 Gauge speaker wire and asked me to try them out. I did so between my then Audio Research SP11 and my VTL 140 mono-blocs. I heard no increase in noise or any hum (I was careful to dress the interconnects away from any mains leads). I can see situations where RFI and EMI is a problem and in such a case one should not use un-shielded cable, and one should probably think about going balanced!  

 George

Several years ago I moved a Class A Preamp PCB to another area of the room with the DMM still connected across it's output, as I had been checking D.C. offset. I was very surprised to see quite a few mV being read at it's output with NO power connected. It was due to RF pickup, possibly from a not too distant FM Stereo transmitter.

Not all RF/EMI results in audible hum, but it can still degrade S/N performance.

 Alex

[sandyk]

9 minutes ago, pkane2001 said:

 

I got about 20m of Canare 4E6S. Most of it went into multiple headphone cables, but some into DC cords since I had some left over. I'm not against experimenting, but I don't bow to JS or to anyone else just because they say something. Especially if that something is highly improbable. Doveryai, no proveryai is my motto 

 

4E6S makes for a wonderful balanced headphone cable even at a 10m length. But, it's nothing special as a DC cord, IME.

 

 Even if I don't hear the improvements that John and others report, I won't  be claiming they are wrong, as my hearing is far more aged than theirs, and not every setup is the same.

It also seems highly likely that in the area I am currently living, that there may not be a need for such measures.

[sandyk]

6 minutes ago, gmgraves said:

Then we're essentially on the same page. End of debate.

NO !

 I heard differences that I didn't expect to hear, and that you believe are NOT possible. 

[sandyk]

17 minutes ago, pkane2001 said:

 

But you would defend their findings without being able to confirm them yourself and without any objective evidence to support them? I'm much more skeptical when it comes to these claims, but I'm always open to hearing real evidence to the contrary.

 

 I didn't say that I would defend their findings, but I certainly wouldn't post  that an experienced E.E. like John was wrong , just because I was unable to hear them for myself.

 I would still invite others to try it for themselves though, to see if others were able to confirm his results, preferably using non sighted testing to rule out Expectation Bias.

 

[sandyk]

2 hours ago, marce said:

Er don't forget I have been doing this for a for last 30 odd years, that is audio systems and before that an amateur musician playing in Brass bands when I was a kid, bass in various bands when a teenager and older.

Worked on audio and video over the years, don't forget we have professional audio companies on our books.

So years of listening and learning, the biggest thing I learned was don't trust your perceptions...

  Marc

Yet you are still using an antiquated SBT with a SMPS ?

Are you afraid that you may learn something that unsettles you if you power it with a decent Linear PSU  or a low noise SMPS with the earth side of it's supply earthed ?

There is quite possibly another U.K. member who is willing to loan you a more suitable PSU to try with that mediocre SQ device.

Yes, I have heard a couple of SBTs owned by a friend who worked in I.T. , both before, and after modifications and a better PSU which did result in a very worthwhile improvement. The unmodified SBTs also sounded  a little lacking when compared with another I.T. friend's (Greg Erskine) Transporter which is still easily outperformed by more modern DACs.

 

Alex

[sandyk]

2 hours ago, gmgraves said:

Also, human beings have no long-term memory for sound quality either. So when I hear people talk about how their components "burn-in" over many weeks or months, I look upon that statement with jaundiced eye, because nobody can possibly remember what something sounded like weeks or months before. If one insists that they can, then I say that person is either delusional or a liar. 

George

 Up until that point I was in agreement with you about slow degradation not being noticeable, but I don't use Tube amplifiers, and semiconductor amplifiers don't slowly degrade in SQ unless due to something like electrolytic capacitors in the PSU drying  out . That is why these days I often check PSU electros for domed tops and signs of leakage.

This became more necessary due to the Pirated electrolyte episode that helped to destroy so many PC Motherboards.

 

I rely heavily on the depth of image and listen for a 3D type presentation with good source material for equipment evaluation after modifications etc., mainly using headphones for this.  I DO notice if this aspect is as good as it was even a year earlier when doing this. If it isn't, I check my B.P. before digging deeper into it.

Perhaps I am a LIAR ???

 

Alex

[sandyk]

26 minutes ago, fas42 said:

When I first got a system working this well that quality lasted about ten minutes, and then steadily vanished - it was back to normal audio, meaning it was obvious that the right, and left speakers were the source of the sound.

Frank

 That is exactly the reason I got involved in the area discussed in the DIY Audio attached link.

I found that the front end was slowly drifting in and out of optimum balance of the input Differential Pair of the amplifier, despite using 2 well matched transistors for both HFE (Gain) and VBE ( Voltage between Base and Emitter).

 

Alex

http://www.diyaudio.com/forums/solid-state/133018-current-mirror-discussion-15.html

 

[sandyk]

33 minutes ago, gmgraves said:

Your remembered impression of anything really specific, might be inaccurate. Specific impressions are very subject to the vagaries of human memory. An excellent example of this is the eye witness to a crime who is sure that he saw the defendant commit the crime, and is later found out to have fingered the wrong man. A lot of research has been done in this field recently. It turns out that memory in humans doesn't work like a recording (which was supposed for decades), that is to say, it's not continuous. The brain "refreshes" the memory every time it is brought to consciousness. IOW, it recalls it and refiles or 're-writes" it. When this happens, all kinds of non associative forces creep into it changing it subtly. Not saying that this is happening in your example, but it's possible simply because you are human. 

 

 I am well aware of this, after years later re-reading my notes that I had to prepare for a Divorce action many years earlier.

 

Much of the testing I do after modifications involves listening to material where there is an excellent 3D type image.

Either the illusion sounds very real , or it is missing something compared with how well you know that it SHOULD sound. 

 Occasionally, I will be surprised at how good it sounds this time, and realise that it is a further improvement.

That is very different to the situation you quoted.

Quote

 "I went to the symphony last night and I couldn't get over how smooth the strings sounded." Now you will remember your impression of the strings, but you won't be able to remember what the strings actually sounded like, just your reaction to what they sounded like"

 

[sandyk]

10 minutes ago, gmgraves said:

Well, that definition fits any properly made shielded cable of less than 10 ft in length; meaning that at audio frequencies, there is no measurable or visible (as on an oscilloscope) difference between a signal at one end of a soldered link or printed circuit track or one end to the other of a short, audiophile "length" (18" - 2 meters) of coax terminated in RCA plugs! A cheap Radio Shack interconnect meets those standards.  

 Yet a device such as a DAT player or even a Nakamichi Tape Deck sounds better when numerous soldered steel links are replaced by copper wire links !

[sandyk]

Just now, gmgraves said:

Well, steel isn't the greatest conductor of electricity, after all.

 

No, but the combined resistance of all the straps is likely to be way less than the less than the resistance of your copper interconnects, especially when you add in plug and socket resistances.

[sandyk]

4 minutes ago, gmgraves said:

 

I have no experience with such modifications, so I can't really make an intelligent or useful comment. I'll just have to take your word for it that the improvement is audible in a DBT between two identical samples, one modified in the manner you outlined and the other left stock. I assume that this is how you ascertained that the unit with the copper straps sounded better than the unit with the stock steel ones. 

 

 A friend and myself had similar models.

No, we didn't feel the need to do pointless DBTs.

[sandyk]

Hi Marc

 Seems like you have the right priorities already.

The main thing is that you are enjoying the music .

All the best for the future.

 

Kind Regards

Alex

 

[sandyk]

1 hour ago, Ralf11 said:

comparisons are nearly pointless without DBTs

 

Music is for enjoyment, not in depth analysis every time you hear improvements when  using different or better equipment.

Many Music lovers will, if the results aren't quite marked, use non sighted  testing to make up their mind.

That is all that is needed.

Music lovers have no interest in having their findings peer reviewed or published in Scientific journals !

 

[sandyk]

5 minutes ago, gmgraves said:

 

On one level you are correct, Alex. If you think some change, no matter how dubious, has improved the sound of your system, then it has because it's increased the amount of pleasure that you get from listening to music on your system. OTOH, such a lassis-faire attitude toward reality only encourages charlatans to sell ever more expensive doo-dads; the function of which in actually improving sound quality is extremely dubious. Now people have a right to believe what they will, but that doesn't mean that these scientifically challenged products can't be, or shouldn't be debated in an open forum like this one, or that curious people shouldn't apply the best available tests to prove or disprove the efficacy of some of these products. 

George

 You have already demonstrated in the quote from you below, that it is virtually impossible for members of a forum like this to effectively use DBTs that will be accepted as proof of anything.

It also shows why Ralf 11's incessant demands for DBTs to be performed are simply his arrogant way of putting down all subjective reports.

Alex

17 minutes ago, gmgraves said:

The caveat here is that the DBT must be scrupulously perfect to be useful. That's easy with passive components or ancillary components not actually in the signal path, but very difficult with active components due to the need to match the level between DUTs precisely. I've read where even a difference of a single dB will cause an invalid result. Add to that the necessity for the un-involved switching operator to also not know what he's switching, or indeed if his action switched anything at all, and that the involved listeners should not be able to see the operator initiate any action, and setting up a proper DBT becomes very difficult. If one participates in a DBT and tells others about it, or publishes the result of a DBT, It still doesn't actually prove anything because one rarely can have the assurance that the test was scrupulously set-up and carried out.