Recording in a Nakamichi

[jayants]

As I am still experimenting on the Recording aspect of my newly acquired BX300 I am confronted with a peculiar issue which I wish to highlight here.

Please listen to the clip - link in divshare below.

Its a small piece recorded in my Nak and the source is FM Tuner.If u listen to the clip u will find a hissing sound in the 1st part followed by the small clip of song.Now this hissing part is when everything in the recording process is on except the Tuner and as the Tuner is put on am sure the hissing part still continues suppressed by the song.I am facing the same issue when recorded from a TT as well.

How do I overcome this noise as am sure it remains in the background OR is it something which I can give it a pass.Experts please suggest.


sample.mp3 - DivShare

 

[reubensm]

Tape hiss is a part of the tape recorder experience. To supress it, record your cassettes using dolby B and play back with the dolby B switch on. Here's some more reading on the subject:

Dolby noise-reduction system - Wikipedia, the free encyclopedia

As I am still experimenting on the Recording aspect of my newly acquired BX300 I am confronted with a peculiar issue which I wish to highlight here.

Please listen to the clip - link in divshare below.

Its a small piece recorded in my Nak and the source is FM Tuner.If u listen to the clip u will find a hissing sound in the 1st part followed by the small clip of song.Now this hissing part is when everything in the recording process is on except the Tuner and as the Tuner is put on am sure the hissing part still continues suppressed by the song.I am facing the same issue when recorded from a TT as well.

How do I overcome this noise as am sure it remains in the background OR is it something which I can give it a pass.Experts please suggest.


sample.mp3 - DivShare

 

[jayants]

Tape hiss is a part of the tape recorder experience. To supress it, record your cassettes using dolby B and play back with the dolby B switch on. Here's some more reading on the subject:

Dolby noise-reduction system - Wikipedia, the free encyclopedia

Thank u so much for this input.Will try it at once.

Have u listened to the clip I posted? Do u think pressing Dolby B in this case will help my case?

 

[Shivam]

Dolby NR versions were made to fight tape hiss. Recording has to be done with this so as to use it. If your recording was done without any NR then using it on playback will lead to treble loss.

 

[reubensm]

yes, listened to the clip

for dolby to work, the tape must be recorded using dolby as shivam rightly pointed out, when you use dolby for playing back a non-dolby tape, there will be significant treble loss. On the other hand, some guys like myself record with Dolby B and playback with Dolby C in order to get reduced tape hiss but enhanced highs/mids.

however the disclaimer, tape hiss cannot be completely eliminated. that is a characteristic of tapes. Some tapeheads of the past used to swear by tape hiss, preferring to listen to music with it, as they felt the high frequencies in the recording were left untouched.

Tape hiss by no means, implies that your cassette deck is not functioning well. Your deck is perfectly fine.

 

[reubensm]

While recording on normal tape, keep the "bias tune" control in the mid-position (neutral). I have done some experiments recording on normal tape with different bias settings. I have noticed that as we add bias (turning the control towards the "+" direction), the highs drop, when the bias is reduced maximum in the "-" direction, the highs increase (the bias control works only during recording, for obvious reasons)

 

[jayants]

While recording on normal tape, keep the "bias tune" control in the mid-position (neutral). I have done some experiments recording on normal tape with different bias settings. I have noticed that as we add bias (turning the control towards the "+" direction), the highs drop, when the bias is reduced maximum in the "-" direction, the highs increase (the bias control works only during recording, for obvious reasons)

Thanks.Yes I keep it in the middle only while recording.

 

[jayants]

yes, listened to the clip

for dolby to work, the tape must be recorded using dolby as shivam rightly pointed out, when you use dolby for playing back a non-dolby tape, there will be significant treble loss. On the other hand, some guys like myself record with Dolby B and playback with Dolby C in order to get reduced tape hiss but enhanced highs/mids.

however the disclaimer, tape hiss cannot be completely eliminated. that is a characteristic of tapes. Some tapeheads of the past used to swear by tape hiss, preferring to listen to music with it, as they felt the high frequencies in the recording were left untouched.

Tape hiss by no means, implies that your cassette deck is not functioning well. Your deck is perfectly fine.

Interestingly I found out that by pressing Dolby C the hissing sound reduces more than Dolby B.So which one should I use?

 

[reubensm]

Dolby C does present a greater roll off. Again, its personal preference, using what works best for you. There are no ground rules here.

I use Dolby B for recording and Dolby C for playback. The recordings sound very good on my Kenwood Car Cassette player too, hence I stuck with this combination.

Personally I've never been allergic to tape hiss as I've grown up on a tape staple and have got kind of used to it.

 

[jayants]

Dolby C does present a greater roll off. Again, its personal preference, using what works best for you. There are no ground rules here.

I use Dolby B for recording and Dolby C for playback. The recordings sound very good on my Kenwood Car Cassette player too, hence I stuck with this combination.

Personally I've never been allergic to tape hiss as I've grown up on a tape staple and have got kind of used to it.

Thanks Reubensm.

I record using Dolby C but while playing I switch off the Dolby to get more clarity on the treble front as well.

 

[Shivam]

Thanks Reubensm.

I record using Dolby C but while playing I switch off the Dolby to get more clarity on the treble front as well.

You can get better results by using NR on playback too and increasing the treble from your preamp/integrated amp.

 

[IndianEars]

Dolby C was a later development ...... almost a decade After Dolby B.

Dolby B provided a touch less than 10 dB noise (tape hiss) reduction.

Dolby C provided Double that. Obviusly, Dolby C is the preferred system.

In Dolby, when recording, the treble on the incoming signal is boosted ( approx 10dB for Dolby B and 20 dB for Dolby C )
and
during Playback the same cut ( approx 10dB for Dolby B and 20 dB for Dolby C ) is applied.

Ofcourse, this is a simplistic explanation on Dolby....

A key issue for cassette recording besides Tape Hiss, is Tape Saturation at High Frequency.

HF tape saturation can be heard as lack of HF resolution, eg when a Cymbal is struck with a wire brush, instead of a sizzle, it will be recorded as a "shhhhh"

To reign in Tape saturation, it is recommended that :

With Normal Tape
Dolby B : The PEAK VU Meter Recording levels should not exceed 0dB
Dolby C : The PEAK VU Meter Recording levels should not exceed -3dB

With METAL Tape
Dolby B : The PEAK VU Meter Recording levels should not exceed +3dB
Dolby C : The PEAK VU Meter Recording levels should not exceed 0dB

You MUST adjust the recording levels as high as possible, within the constraints mentioned above, to reap the max Tape Hiss reduction ..

Enjoy !

 

[reubensm]

Good way of explaining the logic. This is absolutely spot on. Just to add, the quality of tape is also critical, the poorer the quality of tape (or older the tape), the more the hiss (talking from my experience with normal type tapes)

On another note, try out all permutations and combinations by making test recordings. Use settings that work well for you and sound good to your ears. But if you plan to do neutral recordings to share with friends, etc, customized settings may compromise the originality. The ideal logic is to create recordings as neutral or as realistic as the source but that may not always be appealing to the ear

With regard to saturation, some older decks (especially the older Akai decks) had a limiter feature. Although intended to prevent saturation, I always felt that the recordings sounded a bit controlled and artificial when recorded with the limiter on. Our Akai GX39d had this feature.

 

[IndianEars]

The Limiter, was to limit the Peaks at ANY frequency, to prevent Gross Distortion.

It often ( as in the Akai GXC 39D ) kicked in at +3dB. There was even a Peak Red LED Indicator....

 

[jayants]

Dolby C was a later development ...... almost a decade After Dolby B.

Dolby B provided a touch less than 10 dB noise (tape hiss) reduction.

Dolby C provided Double that. Obviusly, Dolby C is the preferred system.

In Dolby, when recording, the treble on the incoming signal is boosted ( approx 10dB for Dolby B and 20 dB for Dolby C )
and
during Playback the same cut ( approx 10dB for Dolby B and 20 dB for Dolby C ) is applied.

Ofcourse, this is a simplistic explanation on Dolby....

A key issue for cassette recording besides Tape Hiss, is Tape Saturation at High Frequency.

HF tape saturation can be heard as lack of HF resolution, eg when a Cymbal is struck with a wire brush, instead of a sizzle, it will be recorded as a "shhhhh"

To reign in Tape saturation, it is recommended that :

With Normal Tape
Dolby B : The PEAK VU Meter Recording levels should not exceed 0dB
Dolby C : The PEAK VU Meter Recording levels should not exceed -3dB

With METAL Tape
Dolby B : The PEAK VU Meter Recording levels should not exceed +3dB
Dolby C : The PEAK VU Meter Recording levels should not exceed 0dB

You MUST adjust the recording levels as high as possible, within the constraints mentioned above, to reap the max Tape Hiss reduction ..

Enjoy !

Wow! That's great info. Will try this out and see the difference. Thanks.

 

[reubensm]

The Limiter, was to limit the Peaks at ANY frequency, to prevent Gross Distortion.

It often ( as in the Akai GXC 39D ) kicked in at +3dB. There was even a Peak Red LED Indicator....

yes, i remember when recording live, it was always used, just as a contingency measure.

 

[jayants]

Hi,

I am a bit confused now.After reading through the posts here and trying it myself I found out that while recording using Dolby C on reduces Hiss considerably and while playing the same recording with Dolby off give pronounced bright sound.


But one of my fellow audiophile enthusiast has something else to say in a different group and this si what he has posted.He is a dedicated NAK listner for years and is quite knowledgable as well.Please go through his comments here :

Uh Oh Jayant. Thats what many individuals with non Naks end up doing, because in most non Naks, the input(recording) and the output( whats recorded on tape) levels do not match at all. On some tapes its lower(its mostly this) and in others, its higher( rare, but does happen) When this occurs, the dolby circuit misinterprets and being a compandor, expander circuit, it causes deemphasis and emphasis on playback erroneously resulting in a terrible sound on playback, resulting in DULL, or BRIGHT playback. This is what has given dolby a bad name amongst folks that do not use it correctly( which is many, including myself, unto 10 years ago!)

Using dolby during recording and not in playback, defeats the very purpose of dolby and one is listening to artifacts and distortion than the real music. This will be more pronounced with dolby C than dolby B.

Jayant, There is no ifs ands or buts about certain facts. If you record using dolby, you are supposed to play back with that same dolby. Dolby is primarily used for noise ( hiss) reduction in tape medium.

Using dolby while recording and not during playback for "clarity" as you mention will only result in a bright sound, not a necessarily clear sound. You might interpret the brightness as clarity, but in reality it is not. The hiss will be pronounced, thereby defeating dolby's purpose completely.

Here is the mechanism of how dolby works:
The Dolby preemphasis boosts the recorded level of the quieter audio signal at these higher frequencies during recording, effectively compressing the dynamic range of that portion of the signal, so that quieter sounds above 1 kHz receive a proportionally greater boost. As the tape is recorded, the relative amplitude of the signal above 1 kHz is used to determine how much pre-emphasis to apply - a low-level signal is boosted by 10 dB (Dolby B) or 20 dB (Dolby C). As the signal rises in amplitude, less and less pre-emphasis is applied until at the "Dolby level" (0 VU), no signal modification is performed.
The sound is thus recorded at a higher overall level on the tape relative to the tape's overall noise level, requiring the tape formulation to preserve this specially recorded signal without distortion. On playback, the opposite process is applied (deemphasis), based on the relative signal component above 1 kHz. Thus as this portion of the signal decreases in amplitude, the higher frequencies are progressively more sharply attenuated, which also filters out the constant background noise on the tape when and where it would be most noticeable.

Hope I made some sense.




Can the knowledgable here please go through the above and share your views.Am utterly confused

 

[greenhorn]

what he says is correct. if you record with dolby on, and listen with dolby off, you are listening to a treble boosted and compressed version.
there are two parts to dolby NR - the pre emphasis/de emphasis and the compressor/expander. At least I will admit that I like the dolby B sound. It adds a certain liveliness to the music. Can't say for sure about C - I dont have any working dolby C decks.

One experiment I would ask you to try is to turn up the treble (around 20db at 1Khz if your avr lets you configure it) with the dolby ON during playback until you get the same amount of highs. You'll notice that now the noise is lower. than with the treble and Dolby off, but the highs are still the same.

In the end, who cares if it is high fidelity or not, it just needs to sound good.


There is an interesting anecdote. While Mixing Disco Inferno by the Trammps, they later realized that they had set the dolby settings in the wrong mode, and after doing a normal mode mix again, the prefered the version with the wrong mode

Sometimes sounding good and sounding correct are not the same thing!

 

[jayants]

what he says is correct. if you record with dolby on, and listen with dolby off, you are listening to a treble boosted and compressed version.
there are two parts to dolby NR - the pre emphasis/de emphasis and the compander/expander. At least I will admit that I like the dolby B sound. It adds a certain liveliness to the music. Can't say for sure about C - I dont have any working dolby C decks.

One experiment I would ask you to try is to turn up the treble (around 20db at 1Khz if your avr lets you configure it) with the dolby ON during playback until you get the same amount of highs. You'll notice that now the noise is lower. than with the treble and Dolby off, but the highs are still the same.

In the end, who cares if it is high fidelity or not, it just needs to sound good.


There is an interesting anecdote. While Mixing Disco Inferno by the Trammps, they later realized that they had set the dolby settings in the wrong mode, and after doing a normal mode mix again, the prefered the version with the wrong mode

Sometimes sounding good and sounding correct are not the same thing!

So do u mean to say recording with Dolby C on I am actually artificially boosting some frequencies of the sound which is not heard if the original sound track is heard normally.

 

[greenhorn]

yes. dolby does this to prevent them from being drowned in the tape noise. during playback, the reverse process occurs.