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All information in these pages is copyright (c) 1989-2003 by Roger Nichols. All rights reserved. Permission for personal reference only, and may not be reproduced by any method without written permission.

Another New Year’s Resolution
by Roger Nichols

Resolve This!
There is still much confusion about the benefits, if any, of the 96kHz sample rate and 24bit resolution. My first impression is that 24bits is always better, but 96kHz is sometimes, maybe better, I think.

Besides any improvement in the quality there may be with 24/96 recording, you must contemplate any additional burdens that may have to be overcome. 24bit requires 50% more storage as well as 50% higher bandwidth in data transfers. If you could just barely playback 24 tracks at once when you were recording at 16 bits, then you will only be able to playback 16 tracks at once at 24bits. If your 16bit song consumed 2 Gigabytes of storage on your hard disk, then the same song at 24bits will require 3 Gigabytes. If you also decide to record at the 96kHz sample rate, the requirements for this one song becomes 6 Gigabytes and you would only be able to playback 8 tracks at a time with the same hardware.

As with any endeavor there are trade-offs. Is the higher resolution worth the reduction in the number of tracks? If I need the same number of tracks, is it worth the expense of bigger, faster hard drives, the upgrade to 96k capable recording devices and the purchase of higher resolution converters? It is a tough call.

Does higher resolution matter?
Last month I sat down with a few other engineers and producers to listen to all of the CDs submitted to NARAS for consideration in the “Best Engineered- Non Classical” Grammy category. There were 267 albums submitted. We listened to every single one of them. Each album could not be listened to all the way through, but we listened to about 1/4 of three or four cuts on each CD. The goal was to make sure that every entry, even if it only sold one copy, had an equal shot at being included in the chance for a “Best Engineered” Grammy.

Why did I bring this up? Well, because every single CD was squashed to death, had no dynamic range and sounded like crap. Instead of listening to find the best of the CDs entered, we had to change the criteria and listen for the least offensive entries. On some of them you could tell that the recording was well done, but in the mixing or mastering the finalizers and plug-ins were cranked up to “eleven” so that their CD would be the loudest when played on the radio or boom box in a trunk-rattling Toyota. Not one of the 267 entries attempted to take advantage of the dynamic range or cleanliness of digital recording.
When each song started playing, the meters on the console jumped up to zero and never dropped below –18dB until the fade. With this much processing no wonder the kids can’t tell the difference between the CD and an MP3 copy of the same song. No wonder after they download the MP3 they don’t have the desire to go buy the CD.

I see questions on the EQ forum like “I am compressing everything to make it very loud, but at what stage should I dither from 24bit to 16bit, and which dithering method is the best?” My answer is that it doesn’t matter. You can’t polish a turd.
What system should I record on?

There are about 3,146,237 different DAW and hard disk recording systems to choose from today. The lowest common denominator is that they will all record 16bit/ 44.1kHz or better. Remember that CDs are 16bit/ 44.1kHz. Even the smallest, cheapest digital porta-studio will record at CD quality.

Some of the best sounding records I have recorded were done on black-face 16bit ADATs with more than 10,000 hours on the heads. If you listen to what you are recording and make it sound the way you want, then it doesn’t matter whether you record 48bit/ 96kHz on next year’s ProTools system, or 16bit/ 48kHz on 10-year-old ADATs. Every one of the hard disk recording systems available today has the potential of recording next year’s “Best Engineered” Grammy.
I have made good sounding records mixing on Yamaha 02-R, Mackie d8b, Digital Performer, Tascam DA-7, Pro Tools, Sony DMX-R100, Logic Audio, Sony Oxford, and Neve Capricorn, and analog Neve and SSL consoles.
There are some consoles that I like better than others, and there are some DAWs and converters that are better than others. Sometimes it is easier to record on better equipment or the latest hard disk recorder, and sometimes one microphone or one converter improves the sound of your work, but if you have a tool to do your job and you know how to use it, it does not have to be the best, shiniest tool, it just has to be a tool that works.

Storage, Storage, Storage
Lets talk about hard disk storage for a minute. For digital audio recording there is no such thing as “too much storage.” The parameters which have meaning to us digital audio guys are; capacity, average seek time, RPM, transfer speed, and interface type.
Capacity of hard drives has reached 180 Gigabytes at a price of about $2.00 per Gigabyte for EIDE drives and $7.00 per Gigabyte for the SCSI version of the same drive. 60 Gigabyte drives can be found for about $120. There is no reason not to have plenty of storage.

Average seek time is the time it takes the read/write head to get from one piece of data to another piece of data. This could be the most important specification for digital audio recording. By the mere nature of editing digital audio non-destructively, the data becomes fragmented on the hard disk and the heads must search across the entire disc for the audio to be played back. A more meaningful spec would be average latency. This would take into consideration the speed of the rotating platter carrying the data. Even if the head moves fast from one place to the next, it must then wait for the chunk of data to come around the platter. If the head gets there just after the data goes by, it must wait one revolution for the data to get back to the head. Here is where RPM comes in. If the disk is rotating at 5400 RPM it takes twice as long for the data to get back to the head as is would in a 10,000-RPM drive, or three time as long as a 15,000-RPM drive.

Transfer speed is the result of two factors. The first factor is the interface used to connect the drive to the computer. The fastest interfaces today are UDMA 133 at 133 Megabytes per second, and Ultra 160 and Ultra 320 SCSI at 160 and 320 Megabytes per second, respectively. Even though Fire Wire (1394) is the current buzzword, the transfer rate is only 400 Megabits per second. Notice I said MegaBITS. 400 Megabits is only 50 Megabytes per second, or about 1/3 the speed of UDMA and SCSI.
It must be noted that there is no such thing as a Fire Wire interfaced hard disk. The drives are usually EIDE and are connected to a converter that translates the data stream to 1394 format. Because the 1394 transfer rate is slower than EIDE, there is no speed penalty for the conversion and 400 Megabit rates can be easily achieved.

It must be noted that these interfaces are backward compatible with earlier, slower versions of hard drive interfaces. This means that a computer with an older, slower disk controller can still access data on the new drive, but at the slower transfer rate. In order to transfer data at the highest speed, you must have a matching hard drive controller in your computer.

Hard Disk Tricks
There are a couple of ways to cheat when it comes to hard disk storage. First, if you don’t have a 15,000 RPM drive and want to improve the multi-track reliability of your DAW, try partitioning your drive into smaller logical drives. 9 Gig partitions work well. If you have a 36 Gig drive, then you would end up with four 9 Gig logical drives. The advantage is that the heads only have to move 1/4 the distance from one chunk of data to another, lowering the average seek time. This will not work if you record 24 tracks on one logical drive and another 24 tracks on another logical drive. If you are going to split tracks, they must be split across two physical drives.

Another trick is a hard disk system from Medea. They use EIDE drives in an enclosure that are connected to the computer by a SCSI interface. The drives are configured in a RAID configuration that makes your computer think that you have a 10,000 RPM 160 Gigabyte SCSI drive instead of two 80 Gigabyte 5400 RPM EIDE drives. Cool, huh!

The End
Now you will have to excuse me, I have to make room on my desk for my new 48bit/ 192kHz Digital Audio Workstation.