Hello everyone. Numerous requests for CD Mastering tips and guidance has prompted the main topic for this issue; CD Mastering. One could never hope to cover this topic of mastering audio in a short newsletter. I will try to address the basics rules I follow when undertaking any mastering and hopefully provide everyone with enough information to get started. Windows 98 information is another one topic that has us all tip toeing cautiously about. I will share some of my preliminary WIN98 findings here, but check this WEB site for a "Your Audio Computer and Windows 98" Workshop soon.
After the Mix
Recording and mixing completed, you are now ready to make that precious CD as final preparation for the "Glass Master CD". Why master at all? You have spent countless hours mixing everything "just right" and all the tunes sound great. You are ready to dub the entire compilation to your DAT or burn a CD. After doing so, you soon discover that some songs are too "quiet" compared to others. Some songs may be much "thinner sounding" than you remember them originally. Why, because now you are hearing it within the context of your album. So what now? Volume levels throughout the entire CD or tape should be consistent. Levels that change from song to song detract from the total musical experience resulting in some of your tracks being masked by the listening environment's ambient background.
Your Master should have as much dynamic range as possible within each track. Having hot and consistent volume levels alone is no guarantee to keep your music "alive" for the listener from start to finish.
Mastering is an engineering process by which the songs for the CD are ordered as desired with the desired feel and flow from one song to the next. Sonically, all the titles should have a consistent listening level. This can only be accomplished by processing and manipulating the audio to get the very best sound possible for each track. "Maximizing the Musicality" is the ultimate goal. Accomplishing this is easier said than done. You, as the mastering engineer, must have the foresight and imagination to listen to the music and imagine what it should sound like. Add to this the knowledge to bring your imagination to life, through successful manipulation of the audio with tripleDAT.
Where to begin
Do you have the tools you need for mastering? Aside from your computer, tripleDAT, FireWalkers and Osiris, you should have a good set of monitoring speakers. These should have as flat a response and as wide a frequency range as possible, in a good listening environment. Speakers should be positioned equidistant and at ear level. If you are mastering your own work, you know what kind of sound you are pursuing. If not, get an idea of the desired sound from the artists. In both cases, you can use the work of other artists with the same or similar sound that you are pursuing as a reference to the dynamics and frequency range. Using "Warp" mode in the WaveWalkers, you can activate the Spectral Analyzer and get a visual view of the major frequency range and use this as a guide to EQ settings for your master. Record a sample from the reference CD you have chosen and then listen to the same track in as many different stereo systems as possible. You will learn how this sounds on your system and master accordingly. What you hear through your monitoring system will influence your mastering decisions, so the better your system, the more details you detect. This directly affects your mastering decisions. Here are some simple to rules to get you started.
Rule #1 - Know how your system sounds in comparison to other systems. This is the first step to successful mastering.
Rule #2 - The foundation of good mastering is done in the mix, which is dependent on the initial recording. "Garbage in - Garbage out"
Rule #3 - Take your time. Merge and listen to the entire compilation uninterrupted and make note of your first impressions and any anomalies you encounter. Rest your ears and listen again, track by track, taking notes of what you imagine the sound to be, and what is needed to achieve this (EQ, Compress, frequency etc). Don't be afraid to experiment.
Rule #4 - Don't compress for the sake of bringing up volume levels. Over compression usually results in am overall sound that may easily fatigue the dears of your listening audience within the first or second track.
Rule #5 - Listen, listen, listen, in as many different system conditions as possible before your declare your work a finished master. Another objective listener may identify something that you missed due to the sheer repetition. Solicit the aid of another set of ears (your spouse or partner or friends).
Arrange all the songs in the order they need to be on the CD. Adjust all the fade-ins and fade-outs and cross-fades to the artist's liking. Listen to the last part of a track and let it flow into the next to hear the level differences. Listen to the entire compilation from start to finish, uninterrupted. Make notes.
Compare track levels and note changes you should make. Levels can make or break the album. Each track must be as loud as the next, but not unnecessarily loud. Normalize each track (Cutter Hotkey "O"). Listen and observe the waveform amplitude.
Utilize the free track space in the arranger. Although you can run lots of DSP in real time within tripleDAT, it is desirable to merge your DSP into new files. There are plenty of tracks to merge little test files for comparative purposes or to evaluate your mastering decision. When you drop them in the arranger, they instinctively lock to their original time line only on a different track of your choosing.
Normalize all tracks. A single loud snare hit can severely limit the amount you can normalize, or increase the gain. Normalizing will only bring the highest peak in the file to 0dB and the overall volume proportionally. It may be necessary to change the level at specific samples that effect the loud peak. In the Cutter the "O" hot key will peak search the file, raise the gain of the file to 0dB at the peak, and place the cursor there. You can then zoom in and change the volume level of just that peak. Repeat these processes until you are satisfied that no further increase in gain can be attained with this method. Listen to the whole track.
Limiting should be used as a tool to aid in "normalizing" and as a final compression stage to boost some gain. Sometimes it is not feasible to lower every peak encountered manually as is step three. The waveform is denser near the zero energy line making it easy to estimate an average dB level of the loudest portions of the file above zero energy, excluding the high peaks. Start working on a section with some visible dynamic contrast. Highlight enough of the transition to make a sensible music loop. Set your limiter to a 0.00ms attack, 1ms release, a ratio of 1.5:1 (to start) and raise or lower the threshold from the scrolling buttons to the determined average level. Merge the track and listen again. Observe the way that dynamic change has altered the waveform representation. Examine the highest peaks at a high zoom level for waveform shape consistency. If some peaks are too "flat topped", they will discolor the mix. Normalize the track (Cutter "O" Hotkey) and listen to the section. You will hear the result of a gain increase. Depending on the musical genre, you could merge your tracks with the Limiter Gain boosted. A nice trick to compress it and keep it all hot. If it is not acceptable you tray another merge of the same block with a higher threshold. Use your creative judgement. Don't fall into the habit of trimming the entire waveform flat.
Compression will bring up lower level signals and compress the higher levels so as not to overflow the signal. Compression should be used more sparingly during mastering than when tracking. Using too much compression can destroy the dynamic range removing the 'life' from the performance. Each track is different and should be treated so. There are no standard settings for CD mastering. Typically, ratios are set between 1.25:1 and 20:1 and a threshold between -5 and -10dB; attack between 0 and 1ms with a release of between 15 and 125 ms. These make a good place to start.
Adding EQ to the final master will affect all sounds within the frequency range and change the gain of the overall file. You may need to decrease the overall gain before you EQ to allow some additional headroom, and avoid overflows. The rule of thumb is "less is more". EQ settings vary from track to track. The best method of finding the frequencies needed or unwanted is to set up a narrow Q and sweep the frequency range in real-time. This will make the frequencies stand out with the amplitude high. When you find the frequency you can boost or cut it as needed. You may want to roll off the Bass below 50 Hz if they are too prominent. If your music sounds thin, the range from 55 to 130 Hz will bring out more fullness in the Kick and Bass. Alternately, this area can be a bit too "boomy". Cutting some frequencies in this range and boosting others in the next range, 130 to 220 Hz, will add more definition and clarity to the bass. This area can also bring out the lower end of midrange instruments such as piano and guitar. The range of 225 to 750 Hz covers the vocal and low-mid ranges. 725 Hz to 2 K will bring out all types of mid instruments. 2K to 5K is where the snap of the snare can be and the upper harmonics of various instruments and vocals. 5K to 10K is where your can cut or boost the brilliance of the instruments like high hats. Merge a small section first for evaluation. If it is satisfactory, then merge the whole file and listen again.
If you have Osiris, you can enhance the low and high harmonics. *Osiris does not "add" new frequencies, rather it "enhances" only existing frequencies. Using Osiris when mastering and keeping your frequency ranges in perspective can add a whole new dimension to mastering. Use the in/out switch to set a frequency level in real time. This is a separate topic.
Merge each intended CD track with their DSP and volume settings into a new file from the Arranger. If you have any fades already set for each file, you should consider merging without any fades or cross fades.
Set your DAO markers and burn the first CD to evaluate. Use this CD to listen to various sound systems and for comparison with your initially chosen "reference" CD. You want to be sure that your Master sounds just right. If you have already set the DAO markers you should not have to do this again. When merging new files, they will drop on new tracks at precisely the same time as the original.
Listen again on as many different stereo systems as possible.
Here are some final points that need to be mentioned. If you are a real "newbie" make sure you have a good understanding of what you are about to do. Learn to apply that knowledge using the tools you have "before" you commit to any time sensitive CD project. Ensure that you have plenty of hard disk space for merges and image files. Don't be afraid to experiment. The newer you are to this skill of CD mastering, the more important it is to make notes at every stage of the process. There are numerous resources on the NET covering the topics of effects and their application. Resting your ears and mind is very important. After 2 hours of mastering at loud levels, take a break, whether you feel you need it or not, because you really do. May the force be with you as you go forth to Master!
Most of you will be pleased to know that I have not had any serious problems with Windows 98 and tripleDAT. This OS came to the public shrouded in doubt and speculation. There were a number of issues such as upgrading from Win95 to Win98 as being an undesirable method. Win98 certainly does require more horsepower than a 486 DX(xx) or even a P166. Overall I have had no nightmares. They fixed lots of bugs from previous versions. There are a number of tools within 98 that will aid in the optimization and configuration of your computer.
It is now very easy to get information about your Hardware and Software configuration and resources. (Accessories/System tools/System Information) The System information manger lets you export the contents to a text file to send to support if needed.
A simplified method of preventing applications from starting with windows and running in the background (in the System Information Window menu tools, choose System Configuration Utility. This is like the old "sysedit" with major enhancements. There is also a section labeled Startup. All programs that start anything with Window is listed here. You can toggle each on or off as needed.
Display properties adds a couple of new tabs, Effects and WEB. Under Effects you can turn off things like Animated Windows and Menus, icon size and colors and window contents while dragging. I turn all these off when using tripleDAT. I also recommend that you view your desktop normally. Deselect Active Desktop under the WEB tab.
I am nearing completion of my tests and will create a new detailed WIN98 online workshop very soon. Keep checking in.
You have mastered your CD and it sounds great. When you compare the volume level to another commercial CD, you notice that the overall level of your music is not as hot. You could increase the gain for the sample and ignore the "overflow" message that tripleDAT gives you. tripleDAT's "perfect volume" takes care of any clipping you encounter very well. Record the output digitally to your DAT machine. Record it back digitally into tripleDAT and presto, you have a hot tracks with little, if any, compression. One can generally increase gain by as much as 4 or 5 dB with no distortion at all.
Add a little extra gain to quiet tracks by arming "PRE" on a track or tracks into the "AUX" of the track mixer. This works well if you are not using any "AUX DSP" and has the potential to increase dynamics without too much compression.
Compressor threshold levels can be more accurately estimated in the cutter. Enable the dB grid (tripleDAT's OPTIONS/dB GRID). Zoom in on the "waveform amplitude" in the cutter. The cutter has a vertical zooming scroll bar for both the Waveform display and the Volume/Pan Window. (See page 46 of the tripleDAT PDF manual for location of these scroll bars).
In tripleDAT's cutter, you can zoom into the sample level and reshape the waveform with volume levels. This is very useful when lowering the volume level within a peak that is producing some distortion, overflow, or other anomaly. Zoom in to the sample view (include or exclude mode) by positioning your cursor precisely on the area targeted with the "+" key. Use the volume window in the Cutter to position volume nodes where needed and work it until you get a satisfactory result.
By Anton Bernhardt 1998
© Copyright Anton Bernhardt - Audiowerks.com All rights reserved 1998