Noise removal and digital remastering of cassette tapes
I'm Yamakawa @HSR_YB, a sound reformer who repairs video and audio data and handles noise.The other day, I received a request to remaster a cassette tape sound source for the first time in a while.
Various magnetic tapes whose storage limit has expired
Originally, we started with a service to improve the sound quality of live sound sources of VHS tapes, but the opportunities to handle magnetic media (cassette tapes, VHS, DAT, etc.) have decreased dramatically, and we only have a few times a year.
It is the mainstream that the playback terminal is broken or the tape is not in an environment where it can be played back due to aging, and even when dealing with old data, it is often a digitized sound source. Most of the work is to receive data from web storage services.
Cassette tape sound source for vocal and piano performances
The client is a female singer who was active mainly in live performances at pubs such as Roppongi and Shinjuku when she was young. She says she's doing another job now, but no one around her can believe she's a former singer.
The only sound source that can be proved is the sound source recorded on a cassette tape. He wanted to improve the sound quality and make the CD easier to listen to in terms of quality. It is probably composed of cover songs and sound sources from about 30 to 35 years ago.
Dolby B alone made a lot of noise
The tape is a normal tape. As is familiar to the cassette tape generation, the analog cassette tape deck was easy to get on with hiss noise called "sahhh". Therefore, most of the models are compatible with "Dolby B", which can reduce hiss noise even with an inexpensive radio cassette player. Rough noise reduction is possible by pressing this button when recording.
There is no noise reduction check in the index, but I tried some Dolby noise reduction (B / C / S) buttons on my TEAC cassette deck.
Perhaps it was recorded with Dolby turned on. When I selected B mode, it became amazingly beautiful. It was recorded on a PC via an audio interface and converted to digital data.
Instrument imbalance & audience noise
The noise of the tape factor has become fairly clean with Dolby. However, the balance of the recorded music itself was not very good.
Vocal + song + rhythm box
Each of these sounds was put together in a PA mixer, and the lineout was probably recorded on a cassette as it was. Only the vocals and rhythm box are extremely loud, and the main backing instrument, the piano, is only small. Since the venue is not big, there is no microphone on the piano, and it seems that the sounds picked up from the off-mic in the store are mixed a little. The voice of the audience is not so loud. (A little worrisome in the part that is not singing and becomes piano only)
The live house sound source (2MIX) of the 80's and 90's just recorded the lineout of the PA mixer in the same way.
There were countless sound sources with poor instrument balance. Most of the sound sources of that kind are of a quality that is hard to hear and cannot be heard by people.
Although it is rough with the latest technology, it is possible to rebalance an instrument by AI analysis from a recorded sound source.
Since we received a slightly larger budget, we also handle the voices of the audience and the noises of concern in detail. Dirty words tend to be mixed in at stores where alcohol is used, and the atmosphere changes just by reducing them.
After fine noise lean, finally mastering processing. Digitally remastered by hybridizing to a sound close to modern quality. I delivered it as a CD.
Hybrid sound source like a precious treasure
Nowadays it is difficult to go out due to the corona virus, and it is a good opportunity to hybridize your own precious sound source as a pleasure of your stay home.
For hybrid sound reform, we also accept requests for higher sound quality of old VHS and cassette tape sound sources. Why don't you make the sound source that is valuable to you easy to hear again?