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My new (old) cable hums in passive mode, no humming with active bass guitar. Can someone expain?

Discussion in 'Miscellaneous [BG]' started by Mucho-P, Sep 28, 2017.

  1. Mucho-P


    Mar 11, 2015
    So I got this second hand cable from my local "Hard-Off" (second hand shop chain in Japan). The place is pretty badly run and staff know little to nothing, so I couldn't ask any questions and there was no trying it before buying it either.

    Bought it anyway because the price was good, actually the same the price as a lot of the crap looking cables they had, but this one has solid metal, unscrewable jack plugs that say "Monster Cable" and the cable itself is really thick and heavy, leading me to assume it is well shielded and better than the usual crappy cables that I already have.

    When I tried it out just now, it played absolutely fine on my active bass, but when I switched it to passive mode, it hums really loudly, whether I touch the strings of my bass or not does not affect the humming. Same on my passive precision, a loud humming noise, unaffected by me touching the strings or not. No humming with my old bass cable, so I am sure the cause is this new cable.

    Tried checking on Internet but have not found anything explaining this phenomenon, so I thought I'd ask here. Anyone know this cable (pic related)? Is it actually a "monster cable" made specially for active basses? Is it not meant for bass at all? Can anyone explain why it hums in passive mode, but not in active mode? I would have assumed the other way round would be more logical..

    Oh yeah, I unscrewed the jack plug on the right, just because I thought it might help. It was screwed tightly shut when I tried it and got the humming noise in passive mode.
    2017-09-28 14.26.02.
  2. Oddly

    Oddly Unofficial TalkBass Cartographer! Supporting Member

    Jan 17, 2014
    Dublin, Ireland.
    I've no real advice to offer but I will say I'd never buy a second-hand cable. If it was working, why wouldn't the original owner have kept it?
    Bob_Ross likes this.
  3. Mucho-P


    Mar 11, 2015
    A lot of people take up a hobby, then change their mind and get rid of the stuff they invested in.
    Especially around here, a lot of good stuff gets dumped (literally), even though its working fine, just because the owner is bored of it, bought something new and better, wants to unclutter / make space in their apartments, etc..

    Regarding my topic, just managed to find something on the Internet. Apparently it is a Monster Cable Studio Pro 1000 Series, of which there are both instrument and speaker cables. Maybe its actually a speaker cable.. Not sure why a speaker cable would hum in passive mode, so if anyone can explain this, I would still will be very grateful!

  4. ddnidd1

    ddnidd1 Supporting Member

    Have you ever checked the TB used classifieds ??
  5. MonetBass

    MonetBass ♪ Just listen ♫ Supporting Member

    Sep 15, 2006
    Tulsa, OK
    Well, how about this: The answer from Fender! Why Instrument Cables and Speaker Cables Aren’t Interchangeable | Fender Tech Talk
    instrumentalist and Mucho-P like this.
  6. Wfrance3

    Wfrance3 Supporting Member

    May 29, 2014
    Tulsa, OK
    i never buy expensive cables. my current favs are the ones that GC sells with the blue shrink wrap on then ends. It's their house brand whatever it is. They have a lifetime guarantee and do the job.
  7. Mucho-P


    Mar 11, 2015
    Aah, thanks a lot for that. It is a speaker cable then and this explains what is happening. Still, very good price, looking at what people are asking for these (used), so I guess I should sell it or get myself a seperate amp / speaker setup to replace my little combo : ).
  8. Mucho-P


    Mar 11, 2015
    One more thought, maybe its just my imagination or the effect of using a much weightier and more solid feeling cable, but I thought the sound of my active bass was actually better with the speaker cable than when I was using my normal instrument cable.

    Since my active bass is producing a high(er) power, lowe(er) impedance signal than my passive bass, would it, maybe, make sense to use the speaker cable (designed specifically for that) for my active bass and could it, maybe, produce a better sound? Has anyone else tried this before?

    I will test this theory tomorrow when I can make a lot of noise (its late here now). If anyone is interested I will share my findings on the matter here.
    Stumbo likes this.
  9. Frank Tuesday

    Frank Tuesday

    Jul 11, 2008
    Austin, TX
    The speaker cable has lower capacitance, which will improve your high frequency response. Get a low capacitance instrument cable. Noise rejection and better HF response in on cable.
  10. Mucho-P


    Mar 11, 2015
    I guess that makes sense. Are you saying most of the average instrument cables out there are not "low capacitance" (don't really know what that means.. sry)? I definitely got a better high frequency response from my monster speaker cable, it sounds rounder and clearer than my cheapo Planet Waves instrument cable. Is the gold plated jack plug just marketing BS or anyone thing that makes an audible differnce, e.g. like better high frequency response?

    Also noting that there is no discernible noise difference between my crappy instrument cable and more expensive speaker cable when playing my active Bacchus 24. Maybe I have to get even louder than I do on my little combo amp or start recording with it to notice the difference, but am currently planning on using my speaker cable when playing my active bass.
  11. Frank Tuesday

    Frank Tuesday

    Jul 11, 2008
    Austin, TX
    Gold-plated plug: No sonic benefits. It's actually not a great conductor. But, compared to other metals, gold oxidizes much more slowly. The "benefit" is that your gold-plated plug wont build up a layer of oxidation which could result in a bad contact. Of course if your jack has oxidized, it doesn't matter what your plug is. Unless your entire chain (every cable end and every jack) is gold plated, it's all rather moot. It's easy enough just to clean your plugs and jacks occasionally.

    Very basic answer on capacitance: A capacitor is made when two electrical conductors are in close proximity, such as the core and the shield in an instrument cable, or the two conductors in a speaker cable. When you increase the surface area of the conductors, the capacitance increases. The surface area of the speaker cable conductors is relatively small compared to the shield in the instrument cable. This is why the instrument cable has higher capacitance. You can lower the capacitance of a cable by increasing the distance between the core and shield.

    The passive tone control on your bass is made with a capacitor and the potentiometer. This is a low pass filter, which attenuates frequencies above a certain frequency. The capacitance in your cable also make a low pass filter when plugged in. The longer the cable, the more the high frequency will be attenuated. The higher the capacitance of the cable, the more high frequency will be attenuated. If you want more highs, use a shorter cable and/or a low capacitance cable. Monster make a "Bass Cable", which has high capacitance for more attenuated highs.

    The long answer is much more complicated, with the inductance of your pickups making a resonant filter.
    Mucho-P likes this.
  12. Mucho-P


    Mar 11, 2015
    Thanks for your great explanation. I think I pretty much get it, well done, though I had to google the word "attenuated" ; ).

    I am wondering if a low capacitance instrument cable will really give me the same, imo "better", sound as my speaker cable is giving me right now. I am looking at pic related and am wondering what 3 way wiring adds over 2 way wiring and whether this makes any difference to the signal coming from my bass?

    I understand the noise factor could obviously be a far bigger problem at a gig, e.g. if there are several other amps, equipment, etc. in a small room, not just my little bass amp here in my room, then I may notice the lack of shielding. Would the signal strength of my active bass, assuming its pretty high, be able to overcome that? I guess amps going to speakers have no noise problem, even in a crowded room full of "disturbances", simply because the signal they are sending is so strong.. is that right?

    Just out of curiosity, i understand you might not want to go into another detailed explanation, do you you think that a speaker cable like mine, with an active bass with high output, could produce a "better" (e.g. richer, brighter, fuller, more rounded, dynamic, etc.) or even just noticeably different sound than a low capacitance instrument cable could, by virtue of the different wiring or is that actually not possible?

    FYI - my cable is the studio pro 1000 on the top of the picture guide.

    Attached Files:

  13. Frank Tuesday

    Frank Tuesday

    Jul 11, 2008
    Austin, TX
    Monster cables is a marketing company. They make up lots of meaningless mumbo jumbo to make their very average products sound appealing in ads.

    Speaker cables don't need shielding because the strength of the electromagnetic noise it pick up is orders of magnitude smaller than the speaker level signal. Instrument signal level is much lower, and any noise you pick up is amplified. I would never plan on using a speaker cable for an instrument. Sometimes you'll get lucky, and you'll be somewhere will little electromagnetic noise. More often than not, you're just going to have a noisy signal. You may not have noise in your room, but that certainly won't be the case everywhere.

    Cable capacitance matters much less on active instruments, as the typical output impedance is ~100 times less than on a passive instrument. Running active you shouldn't notice too much difference between instrument cables. In passive mode, you might (assuming your amp/headphones can reproduce the attenuated frequencies).

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