Dolby and pre-recorded cassettes

[Rossb]

I just picked up a couple of pre-recorded cassettes for the first time in about 20 years - some NOS sealed jazz tapes. Played them on the CR-7 and the ZX-7 and had the same results each time - they sounded quite dull with dolby B engaged, and a lot better without dolby, even though they were marked as being recorded with dolby.

This reflects the same experience I had decades ago playing pre-recorded tapes - using dolby seems to roll off the highs a little too much, regardless of which deck they were used on. I had a theory that commercial tapes used a reduced level of dolby, so they sound good on decks which do not have dolby (eg car cassette decks). Any thoughts on this, or am I imagining it?

[rotovator]

Yes,

I've experienced the same. I've been given tons of pre-recorded cassettes from relatives and friends. Most of the dolby B cassttes sound worse if activated. I just listen ocassionally to them to compare different decks, or to compare the pre-recorded cassette against my own recordings of the same album.

I end thinking that no dolby B has been applied, or there is a several dolby miscalibration of the dolby fingerprint in the pre-recorded cassette.

[Marc Hugo]

I seem to experience this too, Rotovator - nice to see you here by the way. My TASCAM seems better with pre-recorded tapes than most of my machines, encoding Dolby B without too severe a loss of HF.

RossB, you're not imagining it!! A friend of mine gave me a CD of female artist cuts made from pre-recorded cassettes played back on his well tuned CR-7. He used a good compnent standard CD recorder - a Philips 795 I think. They (the songs) did not have nearly the same precision and clarity I have come to expect from his Nak when recording from LP to cassette. I know its not comparing apples with apples, but I often end up playing pre-recorded tapes with Dolby off.

MH

[niklasthedolphin]

I think I stated this before but anyway..........

I recognize this describtion.

It's like this:

On good machines with good tapes, double ended NR systems is not an improvement.
Pre-Recorded tapes are aimed on a mass market Cassette player of any brand and level.
So the term "Average" is used to let most people have pleasure from the pre-recorded tape.

Even on mediocre tapes and machines, to take advantage of Double ended NR systems such as Dolby B/C/S or DBX I/II etc. it has to PB on the same machine (with the same NR unit if it's external) with the same allignments in the NR circuits as well as EQ and Rec Level circuits.

Pre-Recorded tapes are, by the way, never as good as home recorded tapes unless your machines is bad.

"dolph"

[Dimitar Georgiev]

I just picked up a couple of pre-recorded cassettes for the first time in about 20 years - some NOS sealed jazz tapes. Played them on the CR-7 and the ZX-7 and had the same results each time - they sounded quite dull with dolby B engaged, and a lot better without dolby, even though they were marked as being recorded with dolby.

This reflects the same experience I had decades ago playing pre-recorded tapes - using dolby seems to roll off the highs a little too much, regardless of which deck they were used on. I had a theory that commercial tapes used a reduced level of dolby, so they sound good on decks which do not have dolby (eg car cassette decks). Any thoughts on this, or am I imagining it?

Sorry, could not reproduce. Non of my prerecorded cassettes ( > 40) sound dull on my Naks and Revox - with Dolby or without Dolby. Almost all of my prerecorded cassettes are normal type I. I find problems only with the cassettes recorded on my Pioneer CTS800 - they sound dull on my Revox and may sound a little dull on the Naks without autoazimuth. But after tweaking the PB azimuth all the highs show up. Again, this happens only with CTS800, everything recorded on Revox sounds great on Naks which makes me think that the CTS800 needs azimuth tunning in order to be in synch with the Naks and Revox.

D.

[Naknut]

Your experience with prerecorded tapes is typical and why so many never view cassettes as a viable recording medium. Being able to control the azimuth will alleviate some of the problem. I use my Dragon as a playback machine for all of my prerecorded tapes because it compensates well with auto azimuth. I always turn the noise reduction off.

[SLA]

If cassette was prerecorded in Dolby B, C, S or DBX then you have to playback it with appropriate Dolby. Otherwise sound will be distorted... (heights will be different then original recording) - no doubt about it.

As to whether one wants to record with dolby it is one's choice - record with different dolbys and if it sound better keep it if not record without. My experience tells me that if recording has a lot of heights it is always better with dolby (I have teac z-7000).

As to why the cassettes sounds dull - most likely they were kept in bad conditions = garage etc... humidity and high and low temperature can kill any cassette. If you have bought it from GW or SA then that is always hit and miss.
Also as said there could be azimuth and other problems (like speed in your deck etc...)

[Teresa]

If cassette was prerecorded in Dolby B, C, S or DBX then you have to playback it with appropriate Dolby. Otherwise sound will be distorted... (heights will be different then original recording) - no doubt about it.

As to whether one wants to record with dolby it is one's choice - record with different dolbys and if it sound better keep it if not record without. My experience tells me that if recording has a lot of heights it is always better with dolby (I have teac z-7000).

As to why the cassettes sounds dull - most likely they were kept in bad conditions = garage etc... humidity and high and low temperature can kill any cassette. If you have bought it from GW or SA then that is always hit and miss.
Also as said there could be azimuth and other problems (like speed in your deck etc...)

I agree as well, most pre-recorded cassettes should not sound dull. I will agree some do and it could be poor Dolby tracking or storage conditions.

But if pre-recorded audiophile cassettes, such as Nakamichi Reference Series, MFSL High Fidelity Cassettes, Audible Images, In Sync Labs. Aesthetic Audio and others sound dull it is likely the playback azimuth out of alignment. If you get the service manual for your deck this may be user adjustable like on the Nakamichi's.

Also the high speed duplicated cassettes made during the 1980's and 1990's which are mostly digitally mastered should sound way better than the CD or sometimes even LP versions. It seems towards the end they finally got high speed duplication somewhat transparent.

Pre-recorded cassettes do not have to sound like pre-recorded cassettes if the play alignment and Dolby tracking are correct. However be forewarned if you have combination Rec/PB head recordings you already have made with the azimuth out of adjustment may no longer sound correct once correctly adjusted.

Also make sure you playback with the correct Dolby On (B,C or S), and only leave Dolby off if the pre-recorded cassette DID NOT use Dolby. I never had Dolby S but I find Dolby S pre-recorded cassettes to sound fine, if somewhat too bright played back with Dolby B.

[iamhifi]

Nakamichi referemce tapes are recorded with Dolby C and real time ZX-9 computer control on a TDK Metal tape. Well my CR-7A does a fantastic job with Dolby B and the Dragon likes no Dolby most of the time and so the ZX-9, but they all work well with dolby b and better with C. I like no Dolby, I am willing to live with a bit of hiss sometimes, and may I say that with a Classic Nakamichi mechanism you can't hardly hear any hiss. Ross you are in for a ride with the ZX-9 and do try all dolby and no dolby on this one you will love it. PS use Blue heaven interconnect.
Angel

[retrokeeper]

Well,you should also look at the tape itself to make sure the pressure pad is in place,the condition of the tape (lengthwise creasing causing dull sound),plus the possiblility of a stray magnetism affecting the sound.And as it was already mentioned,most of these commercial tapes were not made exactly to audiophile standards,not using the best tape formulations either. Rob