This may have been asked before..and apologies if it has..I did search but couldnt find anything.

I have a pretty large CD collection and am in the process of transferring them to an external Harddrive. What I'm wondering is what bit rate do most of you rip at? Obviously it's a compromise between quality and file size. If I'm transferring CD's to my Zen MP3 player I generally go for 192kbps ..but from experience is this good enough for use at gigs or should I be looking at 256 or 320kbps.

Also is MP3 the best option. I've always assumed it is...but are there other options?


Cheers


Robbie

If you have the disc space available then .wav will give the best quality. I rip mine at a MP3 bit rate of 320kbps.

Aha...this good ol' can'o'worms.

Ripping a CD audio track to an MP3 file format most definately degrades the audio quality. Everyone is pretty much agreed on that as that is factual. What bitrate you use to rip to MP3s adjusts the amount of the degradation.

What people have differing opinions on though, is at what point (or what bitrate) your audience would start being able to notice. Ripping to 320Kbps is about as good as MP3 gets and I very very much doubt that ANYONE would be able to tell the difference between that and CD - but... some DJs who use MP3s also mention that they use 256kbps and haven't had any comments about "iffy" sound either.

However, with hard drive prices being incredibly cheap - you might just as well rip to WAV format. It's incredbily fast compared to ripping to MP3, as the PC that you're ripping through doesnt have to use as much brain power, since its not encoding/compressing any data down into mp3 format.

Two other things to consider - If your ripping software offers you options of CBR or VBR (Constant or Variable Bit Rate) choose Constant / CBR - its more compatible with more DJ wares, and therefore keeps your options open in the future - also consider that the higher the bitrate encoding that you use, the more "thinking" a PC or lappy has to do when its playing it back - and the more "thinking" a PC has to do, the more heat the components may generate over the duration of a gig.

Will you be using the files on a lappy, or dedicated DJ hardware such as a Denon DN-HD2500 or Numark/Cortex Etc?.

If you've got the disk space then I agree with Tony, wav gives the best quality.

But remember, no matter how good your sound file, it can only sound as good as the weakest link in your system.

I rip mine at VBR with a minimum of 160, and I've noticed that most of the time they're playing at 220. Whilst I pride myself on giving the customer good sound quality, I think anything higher than this is wasted at a disco.

where I do use wav's is when I'm creating the backing music for Gang Show where it will be used in a theatre.

Its always a tough decision - if space was no issue, i'd stick with a lossless format - however, as you mentioned you had a large collection of music, space may be an issue.

I'd propose using a Variable Bit Rate (VBR) giving you the best quality for the specific track - and keeping file size to a minimum.

I use a ripper called Exact Audio Copy, and the LAME MP3 encoder, and this provides more than adequate quality MP3s.

a simple google for "EAC" should provide you with all the information you need.

Am I right in saying that wav Format is going to give me a file size of 650Mb per CD?

At the moment I'm just transferring to a Ext HD so I can use it with a laptop, but eventually I can see myself investing in a Controller like the HD2500 as that seems to be the way to go. But that's a way down the road and several gigs later I reckon...someone has to pay for it

Thanks for the feedback guys..much appreciated.

With a little variation, from cd to cd, Yes.

So, roughly speaking, a 500gb drive would give you room for around 700+ CDs - for about what? £50 plus £25 for an external USB caddy/casing with power supply etc.

I've been using Audiograbber for ripping, as that gives you tagging information on each track, even with WAV files.

and so the hype and myth continues . . .

First a few facts:
The ear/brain has an infinitely poor memory for sound qualities.
The ONLY way to compare is a proper double blind αβχ test

With no disrespect, this is something I doubt anyone here has the ability to conduct, since the conditions and statistical computations are extreme, to say the least.

Any differences you believe you can distinguish are probably in the perception or the memory, not in reality. If you think you can detect differences but were not in an αβχ test, you are completely wasting your time.

Of course, many flaws/artifacts in audio files are very obvious, but that is because people still use crapware, and the poor old mp3 format cops the blame for this.

I cannot comprehend how people will spend a fortune obsessively pursuing "the best" audio hardware i.e. players/mixers/amps/cables and speakers, only to fall at the first hurdle, the audio source. Did you use crap tools for a ripper, or for encoding or for decoding? Do you even know what the underlying encoding and decoding engines are, hidden behind those glossy façades? You cannot make a silk purse out of a sow's ear.

How many people are in awe of, or maybe bamboozled by the DJ software functionality, but do not stop to even find out what decoding engine it is using?

To summarise in a few lines, what really needs a few volumes.

αβχ testing has demonstrated that even in panels of audiophiles, higher rate vbr settings will produce transparent encoding (transparent = most people cannot distinguish the MP3 from the original in a blind test).

A CBR encoding at 320kbps contains largely fresh air because most frames of music do not reach that level of complexity. However, a vbr encoding is a win-win situation because it allows it the headspace to go to 320 whenever it needs it (i.e. better than CBR 256)

As mattydinx suggested EAC with Lame 3.97, using setting -V 2 --vbr-new, will give you transparent encoding.

i just rip them and pay no attention whatsover to bit rate.

being simple suits me lol

Click this link for a historic article on this very topic.

My considered vote for audio archiving remains EAC or dbPowerAmp encoding to FLAC (Free Lossless Audio Codec) to save approx 30% compared to WAV and flexible tagging. EAC and dbPowerAmp both support AccurateRip meaning best ripping reliability & quality. Note how the FLAC format has gained further respect & a great deal more popularity in recent times, including direct access from the majority of new software titles including PCDJ, VirtualDJ, Traktor, Ableton.

I'd say it depends on your sound system.

Many commercially available PA systems (and doubtless many home-made ones) fall rather short of hi-fi in their ability to give faithful audio reproduction, and in this case I really don't think anyone is going to notice if you encode at 192Kb/s.

However, do avoid 128Kb/s, as this codec incorporates a very sharp high-cut filter which becomes effective above about 11 - 12KHz - easily audible to most below about 40 years of age. (192 cuts off at around 16Khz, which is far less noticeable.)

If you happened to spend 10 grand on your PA system, then there's an argument for ripping to WAV or other lossless format such as FLAC, but this is unlikely.

From a personal point of view, I'd rip at full quality, but as I only play CDs, this is immaterial.

There you go - decision made: Rip at 192Kb/s. (or go variable bitrate as long as your playback equipment doesn't hiccup with these.)

Well that's enough science to make yer head spin...

I didn't spend anything even remotely near 10 grand on my PA system...wish I had that sort of money to spend. So I guess 192kbps sounds about right...what did you mean by VBR causing probs Andy? Is this common?

To be honest I reckon I'll be just using the laptop as a back up at first and use my CD's as my main source and see how it goes.

Anyway..once again..thanks for the very informative and entertaining answers

Some play back devices will not play tracks ripped using VBR. Before you get too involved in ripping loads of tracks, I would suggest you rip the same tracks at different bit rates and play them back to back through your system to see if you can tell any difference.

Its much better to get it right from the start than decide after you have finished that it would of been better done at a higher bit rate.

Makes sense okay...wouldn't be the first time I'd spent days doing something like that only to discover at the end that there was a problem. Nothing more frustrating.

Cheers

VBR is less compatible with the Denon HD2500 certainly. It is compatible, it's just some functions, jump through track is one, from memory do not work.

Personally, I rip at 320k, as space is less of an issue nowadays. Even the 'small' internal hard disk on the HD2500 allows me to have up to 5000 tracks, which is more than plenty as far as I am concerned. If you want more just use an external hard disk. My theory is you can always convert the 320k to less if you want the file to be smaller, but you can't upconvert and gain any quality. Start at the top and work down.

It is true that the higher the bit rate the harder the processor has to work to decode the music, but if that causes a laptop to shut down or play up then I would send it back. Even the most basic of new laptops should be able to handle this task easily nowadays.

That raises an interesting point to me....although it may be covered elsewhere..but seeing as we're here anyway ;)...

What would be the minimum spec laptop you'd consider useable ..say for using with a Powered Mixer unit?

Not my area of expertise, i'm sure some of the other guys can chip in here, but any basic spec new laptop should be up for the job unless someone tell me otherwise. I think they are all Core 2 Duo, 1GB RAM. Reliablity and portability would be more of a concern to me if this was my primary audio source. Don't use the laptop for anything else other than playing audio and don't use it for the internet either. That way it stays 'clean'

The powered mixer doesn't make any difference as this is just mixing and amplifying the signal from the laptop.

You will need an external sound card if you want 2x stereo channels of audio from your laptop, something like the MAYA range (i think you identified this already), or some mixers come with usb audio built in. See the numark range. I have only used an external sound card myself though, not a usb mixer.

VBR used to be a useful setting, back in the days when the prices for solid state memory (memory chips) for pocket MP3 players were sky high, and therefore any squeezing of file sizes to enable more music to be squished into a cheaper MP3 player, was a bonus.

However, nowadays, with hard drive storage being so cheap, for absolutely massive capacity drives, there’s little, if any need nowadays to rip any file using VBR, just to make it around 10%-20% (average) smaller. VBR in itself was a sensible enough concept in it’s day eg: VBR is usually told by the user what it’s MAXimum quality is going to be eg: 320kbps VBR…the encode will only encode at that maximum high bitrate during the parts of the track which needs high bitrates. The encoder will drop itself down to 256kbps, or 192kbps, or lower when it decides (rightly or wrongly) that a lower bitrate can be got-away-with. Most encoders will adjust themselves up or down many many many times during a music track.

Take for example, the track “Come up and see me (make me smile)” by Steve Harley and Cockney Rebel…it’s got several places inbetween verse and chorus’s where there’s just a couple of seconds of silence…(scary enough for a DJ)…but from an encoding point of view, why “remember” those 2 or 3 occurances of 2 seconds of simple silence, in stunningly clear 320Kbps detail – it would be like painting an entire barn door black using a single haired fine brush, rather than blitzing it with a whopping great paint-roller. Those silent parts might as well be encoded using a measly 64kbps for example, to save 256kbs during every second of that silence. However, during busier parts of the song, where there is bass, vocals, instruments of all kinds, all playing simultaneously, then lower bit rates wont capture enough of the detail…going back to our barn analogy, don’t use the large paint roller to try and write the occupiers surname near the doorbell in 1 inch high letters, use the fine brush.

Just on a slightly technical note – most hardware will play VBR fine, if all you want to do is play the track through from beginning to end. It’s if, or when you want to do anything “DJ” related to a track, that you lose certain features, due to the fact that its much more difficult for a precise “moment” of a VBR file to “locked onto” during DJ type manipulation.

As an example, if someone told you to pave a 50 metre pathway using 1metre long paving slabs, you’d know that you’d need 50 slabs. Also, by the time you’d laid 25 of the slabs, you would know that you were halfway along the path. But…what if the sizes of each of the slabs were different, or “variable”… laying 25 slabs might get you further than you expected, or not as far…you could lay 50 slabs and find that you still needed more to reach the end of the path, and so on.

It’s for these accuracy requirements that CBR files will nearly always be more manipulatable than VBR.



The "clean" status of the lappy is a crucial point. Most will say that only Windows (yuk!) and the DJ software itself should be put on the laptop, to prevent driver and other software conflicts...while others have said that they've managed to maintain a stable lappy even with several AUDIO related applications installed on it. Generally, using a lappy thats you're hoping is going to make it through a 5+ hour disco in a hot room etc, once its been stuffed with bulky games, internet browsers, background running virus and firewall software and all those sort of apps, perhaps isn't the best route to a reliable, trouble-free night.

(Oh and take Solitaire off of the lappy too - nothing looks worse than the "DJ" sitting down at the lappy during the buffet, or worse still, the dancing...putting the back eight on the red nine etc...)

Best option, if going down the lappy route - just consider the lappy to be for Disco use only.

Alternatively, bypass Windows, windows drivers and any potential driver compatibility issues etc altogether with a hard drive controller, which a number of members on here, myself included, use as a dedicated way of playing tunes from a hard drive. Depending on makes and models chosen, it usually works out less £££ than a brand new lappy, purchased DJ software, hardware controller, high quality sound card, mains hum audio isolator etc.

Gary - that was a superb description of the way VBR works!

A DJU brownie point should be awarded, I reckon.

Yep. Am glad I asked the question now. Some really informative and interesting stuff there.

Gary, I think your barn door and paving slabs analogies could be a tad misleading.

Audio is made up of frames, and each frame is encoded at a certain bitrate. With CBR all frames are the same, and VBR each frame is encoded according to its needs.

So looking, as I am right now, at a track I encoded at 223kbps VBR (notional average) I see it has 9011 frames. Now, whatever happens to the bitrate within the frame makes no difference, the mid-point is always going to be frame 4506, and so on. So your DJ'ing should not be affected by VBR, or paving slabs.

The setting allows a Max of 320kbps and Min of 128kbps, even for Steve Harley's silences, and the encoding algorithm sorts out the rest at an optimal rate giving no loss of quality and, during busier parts of the song, where there is bass, vocals, instruments of all kinds, all playing simultaneously no lower bitrates will be employed.

You see, I painted my barn door with an Autobrush from K-Tel. It automatically resizes from a 24" roller, to 12" roller to 6" brush, 3", 2", 1", ½" and ¼" so that each part of the door was painted with the precise size it needed and paint was not just splashed liberally everywhere.

Oh, and the occupiers surname near the doorbell, it was airbrushed!

I recently had my patio redone. They took up those boring grey regular concrete 24" x 36" slabs and laid new slabs of varying sizes, colours and striations in natural sandstone imported from India - and beautiful it looks too. I've never DJ'd on it yet.

As for heat problems with laptops, I've never had any. Probably because my laptop stays at home and I use a desktop with wonderful cooling (not to mention lots of other superior functionality)

I use Napster for my music. Most are 192 but some are 128. Regardless, I have had several comments from people that my sound system is very good.

If I was ripping from CD and had a large HD I'd use 320 but only for the sake of it. 192 is easily good enough.

I saw on a site once when someone took a WAV recording, encoded it to 128, 192 and 320 then re-encoded them back to WAV and listed the original WAV file too and offered people the chance to guess which one was which.

Most couldn't tell which one was the WAV file. Those that did were probably guessing and still got some of the others mixed up. Absolutely no one got them all right.

To the average client there simply isn't much, if any, difference.

Yes, I'd agree. I don't think that anyone out on a dancefloor, at a disco, is going to perceive a difference between one reasonable bitrate, and another bitrate. By the time you factor in that each listener is going to be jiggling around, in and out of the stereo centre, with Sharon yelling "Oi! Trace that guy over there keeps checkin; yer aaout! or Dave yelling "I'm goin' for anava beer, you avin' one?" into their respective dual head mounted sonic receptors (Ears)... it's not exactly laboratory conditions. Add a few beers or barcardis into the equation, and its extremely unlikely that anyones going to even notice a difference, let alone mention anything derogitory to anyone, least of all the DJ.

I've heard a few DJs tell me that they feel that 128kbps offers too low a quality (for THEM) in some cases - again, whether or not a punter with beer-ears will notice all the slight audio artifacts that us decerning DJs might have picked up on at home, in a quiet room, within a decent pair of headphones, after playing the same track back at different kbps ratings, and then comparing it quickly to the original CD...well...that's another story.

When asked nowadays, I'll suggest to DJs to simply rip to WAV. The files are the largest out there, but file size isnt an issue in todays market of a 500gb Seagate drive costing only £65 inc VAT. And take about 10% off that price, for every month that goes buy...or so it seems) - If you want to go MP3, I'd go with the highest setting that you can use. Most modern devices will work with 320kbps MP3s (Constant Bit Rate).

The key reason that I would never recommend Variable Bit Rate for DJs in our industry is that whilst the owner of a pair of ears wont come up to you behind the decks and wrestle you to the ground for "only" using Variable Bit Rate... (and I, myself, wouldn't say "only") VBR files from different encoders (or encoding subroutines) Variable Bit Rate encoders/files dont always stick to an agreed industry standard file format- and there's a reason for that - there isn't an industry standard for VBR.

There's certainly some file types that are more prevailent than others - eg. You'll see more files encoded by LAME encoders than by say, BladeEnc for example. However, I was privvy to a hardware test about 1.5 years ago where VBR MP3s made by two different encoders were each burnt slowly onto 2 different brands of CD-R (4 CD-Rs then in total) using a fairly new CD-burner and were tried in 3 hi-fi, 2 car CD players, and a top-end DVD player. The results were that both the CD-R brands burnt using one VBR encoder played back successfully on more of the playback devices, than the CD-Rs made using the files encoded by the other VBR encoder routine.

Whilst VBR will definately not be lacking to your guests ears in any way, shape or form - it is this lack of widely and fully agreed-upon industry standards for VBR files which, in my opinion, makes ticking the CBR, rather than the VBR box at the time of ripping, a much better option for those who wish to retain maximum compatibility for their music, both now and with whatever the future might bring, without having to re-rip their CD collection to take advantage of new features or whatever other benefits future hardware may bring.

The VBR hardware compatibility issues are quite reminiscent to my mind, of a certain mis-match of formats with VHS Video Recorders. If you recorded a 3 hour film on a 3 hour tape in "standard play" on your own Video recorder at home and then took it 'round to your mates house to watch it later, it would generally playback perfectly.

If however, you recorded that 3 hour film on a 2 hour tape, using your video recorders Long Play (LP) mode, and then took the tape around to watch on your mates Video Recorder, it was a real "Fingers crossed" moment as to whether it would play, or not.

Standard Play HAD to be the same on all video recorders (just think of the fun that Blockbuster would have had with VHS tapes if there hadn't have been an industry standard), but when it came to Long Play (LP - 8 Hours recording on a 4 hour tape) and more recently Extended Play (EP - 12 hours recording on a 4 hour tape) each manufacturer could go Sinatra on it...(They did it...theeeir waaay)