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Topic: On "24-bit digital remasters" and remastering in g (Read 24103 times) previous topic - next topic
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On "24-bit digital remasters" and remastering in g

Reply #100 –
Quote
Originally posted by KikeG

So, it was a single-blind test (SBT). I guess if the result would have been the same in a controlled double-blind test (DBT) with more trials. A single blind test can be not very reliable. I don't know of any DBT that has shown differences with green pens. 


One person had two blind turns.
Two persons had one blind turn and one non-blind.



Quote
Originally posted by KikeG

And, what was the result for these other tweaks? It would be interesting to know.


Okay, this comes from memory, so it might not be very accurate.

Componets used for testing:
CD Players: Denon DCD-580, DCD-695, DCD-980, DCD-1290
Amp: Denon PMA-480R, PMA-680R, DCR-435R
Speakers: B&W DM601, DM302; Snell J3.


Green Paint (CD Stop Light) - applied to inner rim, outher rim and cd tray: Major effect on cheap models, minor on the more expensive ones. Audioable as firmer bass.
$20 a pen - I do not recommend it.

Wax (AudioQuest LazerGuide) - applied to bottom of discs. A lot better resolution in treble, slightly better resolution in mid-range and bass -- all players.
$20 for a bottle. Product discontinued. I do not recommend it, cds attracts a lot more dust with this stuff on.

Sorbothane(rubber) feet under CD player + "heavy resonans absorbant material containing lead and used in cars" inside the cabinet: Major difference the three cheapest players. Minor difference on the DCD-1290 - this model actually has a reinforced double cabinet (cabinet in cabinet). Better resolution, more crisp sound.
Feet: $30  Material: $15.

Sorbothane etc under/in amp: No effect worth mentioning.

"Resonans absorbing material containg lead and used in cars" on back side of speakers. Major improvement - the speakers were cheap and did not have very stable case.
$15 - recommended on cheap speakers

RF stoppers (ferrite things) around power cables. Reduces interference from refrigerator, freezer, vaccumcleaner, etc slightly. I currently have around 20 of them on all my units.
$12 in hi-fi store. $1 in electronics store. Recommended if fridge causes problems.

Sillicone under CD tray. Makes the tray close with a much better sound than normally. No sound improvement.

RF stoppers on signal cables - no effect.

AC filter. Filter purchased in a electronic store in loose components. Had to solder the thing together myself. Major improvement.
$40 - highly recommended.

Circle of filt around dome / front af speakers. Filt was 1 cm thick and the circle was 2-3 cm from inner rim to outher rim. Similar filt is present on all Snell speakers from the years before they were bought by Boston Accoustics. Small improvement to treble.

Different expensive signal (cd player <-> amp) cables: The cables did in fact sound different. One of them was from Tara Labs and made the sound worse (sloppy bass and soft mid-range (also called American Sound, as it is typical for American produced speakers)). The cables from AudioQuest were the ones I purchased too many of. They only have shielding in one end, which can make a lot of difference on some systems. I recently made a test on my high end system. There were no significant difference between the AudioQuest cables and the ones that came with the system.
Cables: $20-$50.

Different expensive speaker cables: A much bigger difference than the signal cables. The cheaper models contains thick a (4 mm^2) cable consisting of many thin copper wires. This cable type sounds awful. A more expensive type from AudioQuest has thick solid copper wires around a plastic kernel. These cables has much better resolution than the cheap ones. The best cable I tested was a cheap cat5 network cable (installation type) This cable has 8 thin solid core wires twisted in pairs around themselves. All the full-coloured wires need to be connected to one pole and the rest to the other pole.
Cat5 network cable/installation type: Max $1/meter.

Metal plate stabilizer on top: I don't remember the result.

CD-lens cleaner: Cleans the laser lens with a antistatic brush. When the lens is cleaned, it can read cds more easily. Don't know about improved sound quality, but a cd player that have problems reading a cd is annoying.
$20 - recommended on cd players that have problems reading

cable-plug cleaner: Don't remember either.

Garden tile directly under speakers: Really bad idea.

Garden tile under speakers + spikes: Not a good idea either. Better to place spikes in wodden floor or carpet.

Foam rubber on the walls, wadding on the walls and ceiling, various carpets and more: The biggest improvements here. A cheap system can sound way better by changing the accoustics of the room. Likewise can an expensive system sound rather bad if the accoustics is all wrong.


Well that is most of what I can remember.

On "24-bit digital remasters" and remastering in g

Reply #101 –
Quote
Originally posted by Annuka

One person had two blind turns. 
Two persons had one blind turn and one non-blind. 


Ok, but that's not what double-blind means.

According to the definition given by Dave Platt (don't know who he is, but this is a good definition) at rec.audio.tech newsgroup, definition slightly modified by me:

A double-blind experiment or test (DBT)  is the one in which neither the experimenter nor the subject knows which are the items that are receiving the active treatment. In an single-blind test (SBT), the subject does not know, but the experimenter does, and there's a risk that the experimenter's interactions with the subject can allow an unconscious "cueing" to take place, which covertly may give a clue to the subject about which things are being tested at what times.


Applied to a listening test, the "active treatment" would be that thing whose effect in audibility you are trying to evaluate. In your case the green pens. With audio compressors, the encoding-decoding process.

The only reliable method to dettect differences on "transparency" in sound is a DBT.

A computerized ABX test is one type of double-blind test. Other double-blind method is an ABC/HR test.


By the way, thanks for your long description of your tests.