AB Testing Support

[mwphoto]

Hi All,

Since AB testing comes up a lot (particularly with FLAC) I thought it would be useful to be able to do this without a massive amount of effort.

What I have done is develop a script that takes an original WAV file and chops it into regular chunks. These chunks are then (on a random basis) converted to FLAC.

When you listen to the chunks in sequence the original song becomes seamless, but the encoding method changes at random. So if you believe you can tell a difference you should be able to hear the change.

I have to say, I did this for myself and I am personally convinced that I can hear no difference (I sort of knew it before, but now I believe it in my soul)

I've attached the script, there is some documentation, but at present there's no support. Anyone familiar with perl will have no problem, others might struggle using it. I may develop it further, but have no time right now. I'm just throwing it out there to see who's interested.

Malcolm

Feel free to post your comments back here, try it out, develop it further etc.

[Patrick Dixon]

Terrific idea - well done!

[mwphoto]

Here's a new version that supports MP3 (same caveats as before, be prepared to get into the code)

I've taken a slightly different approach for MP3 (it works the same as it used to with FLAC).

I found a worryingly small difference between MP3 and WAV when I tested (I thought I had better ears!)

Malcolm

It strikes me that there's other 'audio' test stuff that could be done here. In particular I was thinking of 'random' test signal that beeps at different amplitudes, frequencies and locations across the sound stage. You could use it to determine the response of your setup (including your ears). I'll have a think and maybe develop something.

[hifisteve]

Hi Folks.

Well I've just joined the exciting world of SB3 after a friend lent me a spare one which he'd bought for his bedroom. As I told him through gritted teeth "The only way you're getting this back is by prising it from my cold dead hand...."

Anyway, I'd read all that people have said about format, quality, easy of use, not shackling yourself to an 'Apple only' file format (have an MP3 player in my car) and had opted for using Easy CD-DA to rip everything to FLAC.

Out of curiosity, I decided to try comparing an untouched WAV file ripped using iTunes (ripped very fast, about x30) with the same track as a FLAC file produced by Easy CD-DA.

I have to say that despite being a hardened hifi nut of many years , I couldn't reliably separate the WAV, FLAC and original CD through a £3k CD player.

As a result I've decided to save my sanity and do the lot as uncompressed WAV files and invest a bit of money in some HD space.

Has anyone else done this comparison?

[Mitch Harding]

I'm not sure I follow your logic.

You can't tell the difference between FLAC and WAV (which to date nobody has
been able to do using blind testing), so you settle on WAV as your format of
choice?

I think the biggest hassle you're going to have with WAV is the lack of
tagging. Disk space is cheap, so FLAC's main selling points (for me) are no
loss of audio data and tagging. The space saved is just gravy..

On 2/27/06, hifisteve <
hifisteve.23wri01141078146 (AT) no-mx (DOT) forums.slimdevices.com> wrote:
>
>
> Hi Folks.
>
> Well I've just joined the exciting world of SB3 after a friend lent me
> a spare one which he'd bought for his bedroom. As I told him through
> gritted teeth "The only way you're getting this back is by prising it
> from my cold dead hand...."
>
> Anyway, I'd read all that people have said about format, quality, easy
> of use, not shackling yourself to an 'Apple only' file format (have an
> MP3 player in my car) and had opted for using Easy CD-DA to rip
> everything to FLAC.
>
> Out of curiosity, I decided to try comparing an untouched WAV file
> ripped using iTunes (ripped very fast, about x30) with the same track
> as a FLAC file produced by Easy CD-DA.
>
> I have to say that despite being a hardened hifi nut of many years , I
> couldn't reliably separate the WAV, FLAC and original CD through a £3k
> CD player.
>
> As a result I've decided to save my sanity and do the lot as
> uncompressed WAV files and invest a bit of money in some HD space.
>
> Has anyone else done this comparison?
>
>
> --
> hifisteve
> ------------------------------------------------------------------------
> hifisteve's Profile: http://forums.slimdevices.com/member.php?userid=4227
> View this thread: http://forums.slimdevices.com/showthread.php?t=21545
>
>

[ezkcdude]

Hi Folks.

Well I've just joined the exciting world of SB3 after a friend lent me a spare one which he'd bought for his bedroom. As I told him through gritted teeth "The only way you're getting this back is by prising it from my cold dead hand...."

Anyway, I'd read all that people have said about format, quality, easy of use, not shackling yourself to an 'Apple only' file format (have an MP3 player in my car) and had opted for using Easy CD-DA to rip everything to FLAC.

Out of curiosity, I decided to try comparing an untouched WAV file ripped using iTunes (ripped very fast, about x30) with the same track as a FLAC file produced by Easy CD-DA.

I have to say that despite being a hardened hifi nut of many years , I couldn't reliably separate the WAV, FLAC and original CD through a £3k CD player.

As a result I've decided to save my sanity and do the lot as uncompressed WAV files and invest a bit of money in some HD space.

Has anyone else done this comparison?


As has been said many, many, many times on the forum, there is no difference between WAV and FLAC. FLAC is a LOSSLESS format with the same exact information as the original WAV. The only reason I could see for using WAV is too save a wee bit of encoding time. There are many more advantages to using FLAC. But, hey, whatever floats your boot (as the Canadians would say!)

[hifisteve]

I was actually interested in peoples experiences of AB blind testing of PC & SB3 vs reasonably serious CD players, rather than kicking off a discussion over my choice of format.

As it happens, the time difference between creating WAV and FLAC files is quite significant in my experience. Multiplied by 2000 CD, that's a good chunk of my time I'd prefer not to spend sat at my PC when the extra storage cost so little.

[)p(]

As it happens, the time difference between creating WAV and FLAC files is quite significant in my experience. Multiplied by 2000 CD, that's a good chunk of my time I'd prefer not to spend sat at my PC when the extra storage cost so little.

Just lower the compression. The difference in the size of the resulting flac files is minimal. With eac you can do the encoding to flac of the previous track while the next one is being ripped. So it really takes no extra time at all to ripp to flac.

peter

[Mitch Harding]

Ok -- I'm just curious how you plan to handle the tagging issue. Will you
just always use browse music folder? I've never heard the details of how
someone would keep their collection in WAV, so I'm curious to know how it
will work without having any metadata tags to use for navigation.

On 2/28/06, hifisteve <
hifisteve.23y36n1141139960 (AT) no-mx (DOT) forums.slimdevices.com> wrote:
>
>
> I was actually interested in peoples experiences of AB blind testing of
> PC & SB3 vs reasonably serious CD players, rather than kicking off a
> discussion over my choice of format.
>
> As it happens, the time difference between creating WAV and FLAC files
> is quite significant in my experience. Multiplied by 2000 CD, that's a
> good chunk of my time I'd prefer not to spend sat at my PC when the
> extra storage cost so little.
>
>
> --
> hifisteve
> ------------------------------------------------------------------------
> hifisteve's Profile: http://forums.slimdevices.com/member.php?userid=4227
> View this thread: http://forums.slimdevices.com/showthread.php?t=21545
>
>

[fuzzyT]

hifisteve wrote:

> As it happens, the time difference between creating WAV and FLAC files
> is quite significant in my experience. Multiplied by 2000 CD, that's a
> good chunk of my time I'd prefer not to spend sat at my PC when the
> extra storage cost so little.

You may be able to get the advantages of FLAC without spending any more
time than you would on WAV. EAC can be configured to rip and compress
to FLAC in one step. On my machine (Athlon XP 2400) the compression
process only lags a few seconds behind the rip. Other folks are using a
batch process that compresses overnight.

[hifisteve]

Funny you should say that because I had the same thought.

All the WAV files I ripped using iTunes are fully accessible via my SB using the normal browse and search functions and as far as I can see they carry all the usual track info.

I'm not particularly knowledgeable but I'm presuming that tagging adds data to the music file itself. If WAV files don't support this then I'm guessing that either iTunes or SB is able to allow the same level of search features just by using the file/path structure, as I've not used the browser music folder option.

[dwc]

Steve,
I recommend you rip to flac with EAC and flac.exe. You can always go back to wav format, but once you're in wav you can't go forward to flac as you've lost the tags. I think it's best to keep the metadata with the audio file, as opposed to relying on any separate database.

Many of us have friends who have trashed or otherwise screwed up their itunes databases. I can't imagine the pain of having 2000 cd's worth of wav files orphaned if something were to happen to the lone databse with all the tag info.

If you have 2k CD's then you only want to have to do this once. Take the extra time and go all the way to flac.

-Dan

[TheOctavist]

Hey...could someone adapt this and make it an A/B/X setup?/?

I would REALLY like an ABX app for SBT.

infinitely useful..