Reader Feedback

I love HDTV

Dear Editor:
I thought you might be interested in how I am promoting HDTV. I got the tag after I helped my second station with their conversion to HDTV, both early adopters. I have since worked with 5 other stations on their conversions.
Ry Alford
Atlanta, Ga

Calibrating the LFE channel

Dear Editors,
I am always pleased to see BE addressing audio topics, especially new-subjects such surround sound, and the June article Mixing for Surround was a worthy treatment.

I however must take issue with the calibration procedure described in the article. Surround array calibration is poorly understood and often done incorrectly in homes as well as production environments. Quite frequently, it is the .1 (or LFE or boom) channel that is set incorrectly.

The objective is to set the in-band level of the LFE channel for a level 10dB higher than the in-band level of the main speakers, as required in the 5.1 specification. This precludes the use of pink noise for two reasons.

First, the bands involved are different sizes and therefore even perfect loudspeaker/room combinations will give different readings on pink noise. Second, speakers and rooms are not perfect and the lumpy response they provide will give inaccurate indication of the in-band level. This last part is especially important in the lower frequency ranges where the main channels are most likely not delivering the lowest octaves at all and the room's resonant modes radically warp the response curves.

Complicating things even further is the fact that, very often, the main channels are not really full range even if driven discretely. Therefore the sub-woofer often does double duty by reproducing the main channels' deep bass as well as low frequency effects via bass management.

Admittedly, all this was not the focus of this otherwise fine article. Only one paragraph was devoted to calibration. Still, if you have only one paragraph then the following points should be stressed.

First, it is crucial to have the system properly calibrated. Along with all of the old reasons, surround has additional factors that were never encountered in mono or stereo. Second, calibration is not trivial and cannot be done by ear or with simple test signals and equipment. If you don't have the gear or the expertise, then by all means hire someone who does.
John Monforte

Dubbing from tape to CD

I ran across your discussion of how to get audio DAT to CD and Dazzle Movie Star may be the program that the writer was looking for.

My problem is a little different in that I just want to transfer reel-to-reel audio to my CD burner. The computer has audio inputs but no software. Can you make any suggestions?
Patrick McGean

Steve Oppenheimer, the editor-in-chief of Electronic Musician, a Broadcast Engineering sister publication, provides the answer.

Transferring unedited mono or stereo audio from the open-reel deck to a computer and burning a CD is very easy. Obviously, you start by connecting the audio outputs of your open-reel deck to the audio inputs on your computer.

Many CD-burning programs handle stereo recording chores as well as noise-reduction and CD burning, so if your needs are simple, you should be able to do the whole thing with one inexpensive program. Make sure the software you select supports your CD-R drive.

If you look around, you will find plenty of choices. For most CD burning jobs, I like the latest versions of Roxio's Toast 5 Titanium for Macintosh and EasyCD Creator 5 for Windows can record stereo audio and burn CDs. Both programs include noise-reduction tools and several other useful features, support virtually every CD-R/RW drive on the market, and are relatively inexpensive. There are “lite” versions of both programs, but if you are doing a lot of transfers, you probably will find the extra features in the full versions are well worth the price. You can get more info at (opens in new tab). (More free advice: if you want Toast info, you will find it fastest via the site map; the home page is not the greatest.)

If you want to do more advanced editing, you will need higher-level software such as BIAS Peak and TC Works Spark for Macintosh or Sonic Foundry Sound Forge and Steinberg Wave-Lab for PC. These products are extremely powerful, but you pay for that extra capability.
Steve Oppenheimer
Electronic Musician