dbx 1BX III Dynamic Range Expander

skrol
skrol Posts: 3,330
edited January 2023 in 2 Channel Audio
Anyone have experience with a dbx dynamic range expander? I remember these things were well talked of back in the day. I am borrowing one fom a friend and playing around with it. I downloaded the users manual but so far I haven't really found positive benefit for music listening with CD or streaming. It does change the sound but I have not found it to be for the better. Maybe it works better for tape? Am I missing something?

I can see where they could be beneficial in a recording studio or live sound.

Stan

Main 2ch:
Polk LSi15 (DB840 upgrade), Parasound: P/LD-1100, HCA-1000A; Denon: DVD-2910, DRM-800A; Benchmark DAC1, Monster HTS3600-MKII, Grado SR-225i; Technics SL-J2, Parasound PPH-100.

HT:
Marantz SR7010, Polk: RTA11TL (RDO198-1, XO and Damping Upgrades), S4, CS250, PSW110 , Marantz UD5005, Pioneer PL-530, Panasonic TC-P42S60

Other stuff:
Denon: DRA-835R, AVR-888, DCD-660, DRM-700A, DRR-780; Polk: S8, Monitor 5A, 5B, TSi100, RM7, PSW10 (DXi104 upgrade); Pioneer: CT-6R; Onkyo CP-1046F; Ortofon OM5E, Marantz: PM5004, CD5004, CDR-615; Parasound C/PT-600, HCA-800ii, Sony CDP-650ESD, Technics SA 5070, B&W DM601

Comments

  • VR3
    VR3 Posts: 27,964
    Basically boosts the highs and bass, in a nutshell

    Marketing sounds fancier but the truth is that simple sentence above
    - Not Tom ::::::: Any system can play Diana Krall. Only the best can play Limp Bizkit.
  • treitz3
    treitz3 Posts: 18,230
    IMO/IME, it's a gimmick.

    Tom
    ~ In search of accurate reproduction of music. Real sound is my reference and while perfection may not be attainable? If I chase it, I might just catch excellence. ~
  • motorstereo
    motorstereo Posts: 2,042
    Dynamic expanders help a great deal on compressed formats like cassettes, fm radio and vinyl. They're not needed for cd's and make them sound worse.
  • mhardy6647
    mhardy6647 Posts: 32,922
    edited January 2023
    The dbx system is (was) a compander (like Dolby NR) and, as such, is a good tool for noise reduction/dynamic range enhancement for noisy sources of limited dynamic range (records, analog audio tape, commercial FM radio). EDIT: These boxes are just dynamic range expanders; not companders. Derp. Sorry.
    The 1bx was a single-band (edit) expander, if memory serves(?? -as usual, I am too lazy to check!). The 3bx had three bands (again, if memory serves).

    This being said, dbx was made for sources with way less dynamic range than modern digital sources are capable of. Not sure it would do anything but harm for the analog output of digital sources.

  • mhardy6647
    mhardy6647 Posts: 32,922
    Yeah, I went back & checked. 1bx = one band; 3bx = three band. :)
    https://www.hifiengine.com/manual_library/dbx.shtml

    Far from gimmicks, but they were designed for a very different world of signal sources and quality.
    There are also potential unpleasant artifacts ("pumping" being perhaps the most salient) associated with poorly adjusted/implemented dynamic range processing. Those of us who grew up listening to popular FM radio stations are more than passingly acquainted with some of those artifacts. ;)

  • jdjohn
    jdjohn Posts: 2,987
    How about this dbx 228 (bottom unit) I found in my dad's collection?
    3zphqnnvbkwq.jpg
    The top box is basically for input controls...I think.

    I hooked these up in a processing loop (of sorts) with a RTR tape deck, and IMO, it improved the sound a bit...with a little tweaking of the 'expansion' slider. The best setting almost seemed to change with every track. These units are available for sale. PM me if interested. I have a feeling they will end-up on eBay at some point.
    "This may not matter to you, but it does to me for various reasons, many of them illogical or irrational, but the vinyl hobby is not really logical or rational..." - member on Vinyl Engine
    "Sometimes I do what I want to do. The rest of the time, I do what I have to." - Cicero, in Gladiator
    Regarding collectibles: "It's not who gets it. It's who gets stuck with it." - Jimmy Fallon
  • Back in the day these are what we used to lower noise & increase dynamic range.
    Worked great with the formats of the day, as above mentioned, lp’s, tape & also tuners.

    Versions I personally used were from phase linear.
    Couldn’t afford dbx in those days.
    Was getting sound from my lp’s & 45’s that were great.

    Cd’s, SACD’s, DVD-A & the rest are no longer in need of the technology.

    I still use my phase linear 1000 series II when I play my lp’s 👍
  • treitz3
    treitz3 Posts: 18,230
    mhardy6647 wrote: »
    Far from gimmicks, but they were designed for a very different world of signal sources and quality.

    Yeah, I know. I (as well as many others) grew up with dbx. I always thought it was a gimmick. It rarely actually enhanced the sound (for me) and at the time? I seem to remember that I got better results with my EQ's. This was before the introduction of this new fandangled little shiny, small plastic disc that sounded like **** at the time. Talk about ear piercing.....

    I do know that I tried it many times and it never seemed to last very long before I defeated/bypassed it.

    One caveat - I never did try a stand alone unit. Mine was in the various cassette decks that I had at the time, so there may be a big difference there. I seem to remember one deck in particular had a bunch of options with the dbx as well. It's been so long ago, I have no clue what company(s) or even what deck(s). All I remember was the one with many options was a single deck player and it had a black faceplate.

    Tom

    ~ In search of accurate reproduction of music. Real sound is my reference and while perfection may not be attainable? If I chase it, I might just catch excellence. ~
  • mhardy6647
    mhardy6647 Posts: 32,922
    edited January 2023
    yeah -- dbx and cassette not a match made in heaven, although, in theory, it should have done much to level the low-speed, narrow track cassette tape format's playing field with... you know... real tape. B)

    I've had a couple of Technics' dbx-equipped cassette decks, but not terribly good ones, so I don't have anything terribly insightful to say about them. This one (at least) could decode dbx-encoded LPs, which may have been interesting (??).

    htv7pyfeqzjy.jpg

    The issue -- just as with Dolby B -- is the cure worse than the disease?
  • ^ The issue -- just as with Dolby B -- is the cure worse than the disease?

    I agree with this...
    There were some recordings that didn't do well with the expander & noise reduction.
    Was definitely hit and miss. Luckily it was more hits than misses.

    When it was right it was awesome.
  • skrol
    skrol Posts: 3,330
    Maybe I'll try it again with tape instead of CD and see what it does.
    Stan

    Main 2ch:
    Polk LSi15 (DB840 upgrade), Parasound: P/LD-1100, HCA-1000A; Denon: DVD-2910, DRM-800A; Benchmark DAC1, Monster HTS3600-MKII, Grado SR-225i; Technics SL-J2, Parasound PPH-100.

    HT:
    Marantz SR7010, Polk: RTA11TL (RDO198-1, XO and Damping Upgrades), S4, CS250, PSW110 , Marantz UD5005, Pioneer PL-530, Panasonic TC-P42S60

    Other stuff:
    Denon: DRA-835R, AVR-888, DCD-660, DRM-700A, DRR-780; Polk: S8, Monitor 5A, 5B, TSi100, RM7, PSW10 (DXi104 upgrade); Pioneer: CT-6R; Onkyo CP-1046F; Ortofon OM5E, Marantz: PM5004, CD5004, CDR-615; Parasound C/PT-600, HCA-800ii, Sony CDP-650ESD, Technics SA 5070, B&W DM601
  • mhardy6647
    mhardy6647 Posts: 32,922
    skrol wrote: »
    Maybe I'll try it again with tape instead of CD and see what it does.

    couldn't hoit! :)
  • SIHAB
    SIHAB Posts: 4,491
    I have exactly one DBX record;
    6pkca3q5cbaz.jpg

    Would be interesting to try it...
    Speakers: Polk Lsim, ATC SCM19 v2, NHT SuperzeroSpeaker Cables: DH Labs, Transparent, Wireworld, Canare, Monster: Beer budget, Bose ears
  • Never heard a dbx encoded Lp.
    Interesting….
  • skrol wrote: »
    Maybe I'll try it again with tape instead of CD and see what it does.

    Excellent.
    If you have the ability to put it in and out in real time it’ll be a good comparison.


    Report back your findings & thoughts.
  • skrol
    skrol Posts: 3,330
    It has a bypass that makes it easy to compare.
    Stan

    Main 2ch:
    Polk LSi15 (DB840 upgrade), Parasound: P/LD-1100, HCA-1000A; Denon: DVD-2910, DRM-800A; Benchmark DAC1, Monster HTS3600-MKII, Grado SR-225i; Technics SL-J2, Parasound PPH-100.

    HT:
    Marantz SR7010, Polk: RTA11TL (RDO198-1, XO and Damping Upgrades), S4, CS250, PSW110 , Marantz UD5005, Pioneer PL-530, Panasonic TC-P42S60

    Other stuff:
    Denon: DRA-835R, AVR-888, DCD-660, DRM-700A, DRR-780; Polk: S8, Monitor 5A, 5B, TSi100, RM7, PSW10 (DXi104 upgrade); Pioneer: CT-6R; Onkyo CP-1046F; Ortofon OM5E, Marantz: PM5004, CD5004, CDR-615; Parasound C/PT-600, HCA-800ii, Sony CDP-650ESD, Technics SA 5070, B&W DM601