Improving audio

I am running the latest Audacity version on XP. I have several mini cassette tapes that I made years ago and I have loaded then onto my computer using Audacity. Now I am trying to make improvements in the recordings. The tape has the normal tape background noise, low volume in general and some voices are lower than others due to their distance from the recorder. I did not have an external mic for my mini recorder I used for the roundtable discussion. I have tried using normalize, followed by noise reduction then used an external program to even out the low and high voices. All this has made some improvement. Are there other, better things I could try? Is there a preferred order in which to edit audio in Audacity? I am relatively new at this and would much appreciate suggestions from more seasoned users.

Pearlcorder? I am just now retiring mine.

There’s no magic. You hit the steps we would use. Audacity 2.1.0 and on are much better at tape hiss than the earlier versions (post the numbers when you tell us about your system).

external program to even out the low and high voices.

Which is?

Amplify and Normalize are close cousins and all they do is turn the volume up and down. No processing. Each one offers different controls and depend on your goal.

Koz

The only additional thing I’d suggest is equalization. (For experimenting, I usually recommend using the Graphic Equalizer mode rather than the Draw Curves mode.)

The sliders on the right are the high frequencies, and boosting the frequencies above about 4,000Hz will bring-up the “T” and “S” sounds which can help with intelligibility. But, boosting these frequencies will also bring-up the background hiss and any artifacts left-over from noise reduction.

Boosting the 150-300Hz range will bring-out “voice resonance”. Reducing frequencies below 100Hz will reduce low-frequency noise.

Those are just approximate frequencies and every recording is different so you’ll just have to play with the sliders to see if you can get any improvement.

After equalization (or anything that can affect the volume/level) it’s a good idea to normalize (again, since you’ve done it already) before exporting. Normalizing (or using the Amplify effect at the default) will bring the peaks down to 0dB to prevent clipping when you export. (Or, it will bring the levels up to 0dB if they are lower than that.)

Yes, Pearlcorder. I bought an external mic for it some time ago and when I went to use it I found it was no good. Of course it is out of warranty, so I may have to retire my hardly used Pearlcorder. I bought it in 2007 for recording all the history at the roundtable discussion and only later bought the mic realizing how much better the recording could have been. Only used the recorder briefly one other time. Shame.

I am using Audacity 2.1.1 and the audio leveling program I used was Levelator2

I’m wearing mine out. I use it’s ability to vanish while in use (attached, scroll down).

I’ve also nearly never found a condition that it wouldn’t record. If you put one in the middle of the table, I would have thought it would record any conference. I’ve made microphone assemblies that worked for this. Paint it black and it vanishes. I’ve had people not know what it was and pile papers on top of it.

“Tell you what, let’s move these papers so Vancouver can hear us.”

The modern sound recorders can handle many computer microphones, but I wonder if the early Pearlcorders wouldn’t. My microphone powers itself with a little watch battery, but “computer microphones” need power coming up the wire from the recorder.

The only failures (past running out of tape) were putting the recorder next to a noisemaker or finding someone in love with background music. There’s a reason that spy movies always turn on a loud radio in the room just before they announce the secret plans.

My replacement is an Olympus WS-823. It will record meetings and can be configured for entertainment recording and will deliver a high quality WAV sound file.

Koz
FannyPackRecorder.jpg

To be clear, I would put the recorder on the black board instead of the microphone.
Koz

The reason I’m going on about this is to get original recordings up to snuff. It can be nearly impossible to “rescue” bad recordings in post-production.

The kiss of death is a forum posting that uses the words: “help me clean up.”

Koz

I experimented today. I connected my PC mic and it seemed to record great. My ME12 mic mounts right on the recorder. I tried it and with it almost against my mouth I could very faintly hear my voice on playback. What mic are you showing in the photos?

I need to post when I get back to the house.
Koz

Note the last sentence:

— Product Features —

Ideal for transcription
Increases transcription accuracy by reducing ambient noise
Simply plugs into digital voice recorders



My microphone is a Radio Shack 30-3013 tie-tack microphone.

http://www.amazon.com/RadioShack-33-3013-Hands-Free-Omnidirectional-Microphone/dp/B000TLX0A2

When Radio Shack was still breathing, they were $18. It’s omnidirectional. Receives sound from all directions. It’s a Radio Shack version of an existing Sound Company microphone (I don’t remember who).

Before we go too far down this pathway, what problem are we solving?

Koz

Sorry, I got us off track. I know I have a less than desireable recording. I want to try and make it the best it can be. I think many good suggestions have been made and I will try them. Thank you also for the info on the mic. I need to purchase another one and hesitate trying another ME12.

The original equipment manufacturer turns out to be Audio Technica (attached).

I’m not a fan of Audio Technica. They make knock-off versions of better equipment. That makes the Radio Shack a copy of a knock-off.

I need to purchase another one and hesitate trying another ME12.

Don’t. It’s not going to plug into your pre-digital Pearlcorder.

What problem we are solving? I never found any need to put an external microphone on my Pearlcorder. The thing has weapons grade automatic gain control and it will automatically adapt itself to some pretty amazing conditions. It mopped the floor with the competition when it was designed and people are still using them, how many decades later?

Koz

Well you have told me what Olympus could not. That I bought the wrong mic. I had been email their tech department about my mic issue and they could not figure it out except the mic was bad and it was out of warranty. Thanks much!

I thought I needed an external mic because my volume on the tape was not very loud. Now I am wondering if I had the recorder lying flat or on its side possibly with the mic facing away from some of the people. I can see that it should by lying flat because of where the openings are for the mic. Maybe I will invest in the last mic you listed. I have only used this recorder on two occasions and that was 5 years apart.

Which Pearlcorder do you have?

the mic was bad and it was out of warranty.

You do have your timing problems.

The makers knew what they were doing. They said so, clearly in the instructions. You hit Customer Relations with an Olympus recorder design that may be older than they are. There’s only so much you can do with that.

Quick. How many of your friends are still using moving tape? For anything? There’s a recent posting about the last tape maker folding their tent and going home. No more. Bye.


My machine has limiters to deal with rapid volume changes, but it’s impressive feature is the long term volume control. Start the recorder running in any room with the normal number of motors and noise makers, traffic outside, etc. Now scream into it and just let it record. When you play back the tape, it will have recorded your scream more or less normally, but will take the next minute or so to recover and start recording the room noises again. You can hear traffic noises slowly coming up out of the mud and become audible.

This is one of the tricks that none of the digital recorders will do.

There’s a number of complaints from people sending digital recorders back because for the first time, they had a recorder that wouldn’t follow the average volume of the room like the tape machine would.

This is how the Pearlcorder records conversations, too. It should be possible to sit it in the same room with a meeting and as long as the room noises aren’t obnoxious and you don’t try to rapidly switch between different volumes, it should make a clear, audible recording. That means you can’t set the recorder in your pocket or close to any one person. Put it in the middle of the table on a book on a towel and start it.

Put it there in place of the wired microphone. The towel will soak up table noises and the book provides a high-inertia acoustic plate that actually increases the volume of the recording.

I don’t think buying an external microphone is going to help. The 33-3013 is not a particularly crisp performer and you may introduce other problems by doing that.

The ME12 is a noise cancelling, directional microphone. It will record wherever it’s pointed…only. It won’t do a conference room table.

This voice recording thing is harder than it looks.

Koz

I thank you greatly for all of your information. I have a J300 Pearlcorder. Looking in the paper that came with the recorder, I should have purchased an ME15 mic. I now don’t plan on purchasing any mics, just use the techniques you suggested.
From what you are telling me, I think I will pass on buying another external microphone. Thanks for the tips on using a book a towel. I use a recorder so little. Only twice in the 8 years that I have it.
Back in 2007 when I made the recording I used a free audio program called Polder or Polter to load the audio to my computer and enhance the recording. Now I am more computer savy and have been playing with Audacity some and am able to make the audio much better to listen to with the little I know. For as ignorant as I was then, I should be pleased I got the audio I did. For me it was a once in a lifetime 2 hours of hearing stories from great people ran a great company.

Using equipment every four years is extraordinarily dangerous. You take the batteries out, right? If you don’t, one of these times you’re going to try to use it and the battery compartment is going to be flooded with caustic, orange crud from the leaking batteries … and that’s the end of the recorder … and the job.

Try it on a non-critical recording session before you really need it. Many of the panicky postings on the forum are from people who got the equipment out the shipping pack, turned it on and tried to record an audiobook. That doesn’t work for most people.

Koz

Pretty much standard practice for me to take batteries out of anything not used on a regular basis. Thanks for all of your help.