Boombox with dbx?

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caution

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Some of you are may be familiar with dbx. It's similar to Dolby in that it reduces hiss, nearly eliminates it actually, but moreso it's a compressing/expanding (companding) process that greatly expands dynamic range. There are some drawbacks such as "breathing" during quiet passages and finicky about recording levels. I used to record CDs back in the day with dbx on my old Aiwa deck, but unlike Dolby its unlistenable on a non-dbx system.

I did some searching a couple years ago and actually found one boombox with dbx, but cannot remember how I found it or what model it was. I know that it was black, a later model probably made in or after 1986 by one of the big names, and was either a 3-piece or looked like one.

It's exceedingly rare among portables. I only know of three models. Two are Walkmans - the Panasonic RQ-J20X and the Teac PC-7RX. The Marantz PMD-430 also has it.
 

hopey

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How good is dbx. I don't know if it being on a portable. It's a case of production cost and volumes. Dolby c is just two b stacked as the chips where made in large volumes this would have made it cheap to make verses the new dbx.
 

Transistorized

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I have never had an opportunity to try out dbx. I have heard that dbx usually only sounds good played back on the original deck that recorded it and that azimuth alignment could throw off the sound from one dbx machine to another.

Not sure if any of this is true. Would love to hear a finely tuned dbx machine one day
 

Transistorized

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Lasonic TRC-920 said:
Is DBX like Dolby C? In the fact that recorded Dolby C tracks can't be played on anything but C decks?
That is correct. Once Recorded using dbx it needs to be played back in a machine with a dbx decoder either built in or added to to the deck
 

Lasonic TRC-920

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Transistorized said:
Is DBX like Dolby C? In the fact that recorded Dolby C tracks can't be played on anything but C decks?
That is correct. Once Recorded using dbx it needs to be played back in a machine with a dbx decoder either built in or added to to the deck
Yeah, I can see the limitations with that. Of course, back in the day, you might only go from your cassette deck at home (home stereo or boombox) to the car stereo, so that really wasn't that big of a deal.

hopey said:
Dolby c is only mild and can be played on any deck. That's the reason it won out.
I thought I remembered something like that. Thanks
 

Ghettoboom767

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My Alpine 7347 has it! Like said here you have to have a DBX encoder to record in real DBX for mat and a player that has DBX to play it back on correctly.
Yes let me know what Boombox has it as I’d like to have one with DBX.
 

caution

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hopey said:
How good is dbx. I don't know if it being on a portable. It's a case of production cost and volumes. Dolby c is just two b stacked as the chips where made in large volumes this would have made it cheap to make verses the new dbx.
You are correct, as it turns out I was thinking of AM stereo, not dbx. I did a loooooot of searching for a dbx boombox though, I even tracked down all the dbx ICs that were manufactured for tape decks and the like, to see if I could find it referenced on a parts site. Nope. They simply never existed in a blaster, only a couple of Walkmans, some car stereos, and this small device that patches into the headphone jack to give you dbx-processed audio externally.


Transistorized said:
I have never had an opportunity to try out dbx. I have heard that dbx usually only sounds good played back on the original deck that recorded it and that azimuth alignment could throw off the sound from one dbx machine to another.

Not sure if any of this is true. Would love to hear a finely tuned dbx machine one day
It shouldn't matter if you play a dbx-encoded tape on a system with better alignment, but going the other way you may notice some highs missing, although you'll still have highs due to the way it processes the signal. dbx synthesizes highs beyond that which the tape head is capable of.


Lasonic TRC-920 said:
Is DBX like Dolby C? In the fact that recorded Dolby C tracks can't be played on anything but C decks?
It's way worse than Dolby C. Way worse. Like hopey said it's listenable with or without B/C NR, but not dbx. It does so much compression, that without the re-expansion circuit there, it's lifeless and tinny. But, that's what has to be done to get better results than a system like Dolby that's so mild it's still listenable without it.

There are different versions of dbx but most are type I for movie/album studio mastering, or type II for noisier media like cassettes and LPs. I don't think any dbx cassettes were ever released, but some "dbx discs" were, and you needed something like this to play them back properly. There's also another version embedded in the MTS stereo protocol for VHF TV audio. Back in the late 80s I purchased one of these so I could get stereo from my TV.
 

Ghettoboom767

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Thanks for the info Caution,yes if I hit DBX on my car stereo it really compresses the sound and it doesn’t sound very good playing a non encoded regular tape.
I’d like to have one of those Walkman’s!!😊😎🎶🎼📻
 
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