Subwoofer: couple or decouple?

Discussion in 'Audio Hardware' started by audiorocks, Jan 10, 2017.

  1. audiorocks

    audiorocks Active Member Thread Starter

    Location:
    California
    I just got a Rythmik F12G sub (upgrade from a Pinnacle Baby Boomer) and I'm loving it. I have it on spikes which are on coins on my hardwood floor. I'd like to replace the coins with something cooler so I checked out Herbie's site but all of his stuff seems to be geared toward decoupling. In my experiments, decoupling works great for all audio components (I use Townshend Seismic Pods) but it does hurt performance when applied to the bass driver. For this reason I think I want to couple the subwoofer to the floor as opposed to decoupling it.

    Everything in audio seems to involve a series of tradeoffs and there is very likely some performance gain to be had by preventing micro-vibrations from the ground from affecting the sub (decoupling). However, in my experience, for bass performance, the performance gain enjoyed by coupling the sub to the floor would clearly outweigh it. I called Herbie's and the guy there was convinced that decoupling is the only answer so I wanted to check with you guys on this.
     
  2. Strat-Mangler

    Strat-Mangler Forum Resident

    Location:
    Toronto
    The purpose of decoupling is to eliminate any rattling (objects) or booming caused by carpeting or anything else which picks up on the vibrations traveling through the floors.

    This leads to more accurate tighter bass. If you're more used to booming bass, this might inaccurately be interpreted as the sub's performance being negatively affected in volume but in reality, you're hearing the unadulterated bass. Placement also factors in. Subs placed in corners will usually yield stronger performance at the same volume than if it's out in the open in a room.

    Once decoupled, if you find bass to be anemic even when cranked, there's a possibility your sub is underpowered for the room you have and that having it boom with the aid of the floor which amplified those frequencies was just masking this symptom.

    For music playback, a tight accurate subwoofer is always preferred. When a note is played on a bass guitar (for instance), you want that note to be history before the next one is played. You don't want the decay of the first note to be part of the sound as the 2nd note is played. That makes things sound muddy and boomy which is not what I find to be musical.
     
  3. PIEP

    PIEP Active Member

    Location:
    Firenze, Italy
    neoprene 1' thick on the floor, than marble 1' on neo and sub on mar :righton:
     
  4. chervokas

    chervokas Forum Resident

    My experience even on a tile over concrete floor is that decoupling (I use an auralex Subdude platform), is excellent for cleaning up room rattling and improving bass performance with the sub in my system.
     
    fuse999 likes this.
  5. Kyhl

    Kyhl formerly known as Strabo

    Location:
    Savage
    I opted to use the standard rubber feet that came with my Rythmik hoping it would somewhat decouple. Mine is down firing and sits on carpet over a concrete slab. Honestly, I don't care what the feet are because it works. Bass traps were more important than feet type.
     
    chervokas likes this.
  6. I decouple with Herbie's square fat dots under the four feet of my sub. Works great!
     
  7. Waxfreak

    Waxfreak Forum Resident


    My sub is front-firing but has a down-firing port. The rubber feet do a good job of decoupling. Dunno whether an Auralex would affect the port's performance by absorbing part of the energy that is suppossed to bounce off the floor and go to the room ?
     
  8. F1nut

    F1nut Forum Resident

    Location:
    The Mars Hotel
    The sub in my HT room sits on carpet over concrete. With the rubber feet the bass was muffled and boomy. I add spikes, which cleaned things up quite nicely.
     
    Cliff likes this.
  9. chervokas

    chervokas Forum Resident

    Yeah, no idea myself, probably not an appropriate set up for that application.
     
    Waxfreak likes this.
  10. audiorocks

    audiorocks Active Member Thread Starter

    Location:
    California
    Everyone here seems to be in favor of decoupling for subs. So all of the sub companies shipping their units with spiked feet are uninformed?
     
  11. Stephen Syli

    Stephen Syli Well-Known Member

    Location:
    Rivington UK
    I've decoupled my RELL Stadium III, and it's a definite improvement. Room resonance , boom, decreases which may be perceived as 'worse', with my sub I just fine tune the output. You then have the bass, which is deep but not turning your home into a boombox.
     
  12. chervokas

    chervokas Forum Resident

    Maybe the companies shipping their subs with spikes are looking to have cabinet resonances terminated. The theory behind coupling something like a speaker cabinet with spiked feet has always been kind of contradictory -- usually offered as the reason for it is some kind of attempt to drain mechanical resonances from speaker cabinet to floor, though I'm not sure that actually works mechanically, and if it does maybe there should only be one spiked foot and three decouplers; or, alternated, it's kind of a mechanical high-pass filter keeping low frequencies from passing back and forth, maybe that works with subs and things like turntables. In my installation, with a very dead cabinet Velodyne and a tile over concrete slab floor, I got freedom from room rattling (walls, furniture) with cell-foam decoupling (also it raises the sub a couple of inches and to me placement at precise distances away from floors and walls to minimize speaker boundary reinforcement and cancellation are a big part of sub placement). Maybe if a device is designed with spiked feet it should be used with spiked feet. Or maybe it's just one of those things in product development that are done because it's expected by the target consumer but the spikes vs. blocks or other kinds of feet, don't make any difference.
     
    Last edited: Jan 11, 2017
  13. audiorocks

    audiorocks Active Member Thread Starter

    Location:
    California
    Rythmik and Pinnacle ship with spikes for sure. I bet most or all do as standard or as an option. Also Tekton does with their speakers.

    My room doesn't rattle so maybe we have different goals. I've noticed much punchier bass with more impact when coupling speakers and subs to the floor compared to decoupling. Not boom. This is on hardwood (well, bamboo so softwood). Decoupling works much better for mid and high frequencies IME so I do decouple my main speakers (monitors).
     
  14. Kyhl

    Kyhl formerly known as Strabo

    Location:
    Savage
    Rythmik ships spikes as a $15 add on option for the F12. Their standard is rubber feet at no charge.

    I inquired about spikes at a $45 upcharge when ordering a DS15SE, sealed downfiring 15" in ebony, they didn't really speak to the virtues of spikes. Instead they asked why I thought I would need them.
     
    Last edited: Jan 11, 2017
  15. MaxxMaxx4

    MaxxMaxx4 Well-Known Member

    Location:
    Winnipeg Canada
    I use an ASC sub stand.Raises the sub off the floor 15" and treats the bass.The end result is more resolving bass.
     
  16. Stephen Syli

    Stephen Syli Well-Known Member

    Location:
    Rivington UK
    I think that a spiked contact attempts to limit the amount of energy being put in to the floor, which is a good thing. However this means you're not draining it away from the speaker, from my experiments this is a very bad thing. Bamboo flooring is going to greatly reduce the amount of energy going into the structure of your house, as it's good at reducing energy flow. Again however, it seems to me, energy drain is possibly reduced from the speaker.
     
  17. audiorocks

    audiorocks Active Member Thread Starter

    Location:
    California
    I always thought that spikes were meant to concentrate the weight of the sub into as small a surface area on the floor as possible so as to maximize the pressure at those points and thereby couple the floor and sub.

    I will try the rubber feet that also came with this sub and report back.
     
  18. Kyhl

    Kyhl formerly known as Strabo

    Location:
    Savage
    @audiorocks, you have it correct, spikes couple. The question is, do you really want it coupled to the floor?
     
  19. chervokas

    chervokas Forum Resident

    The rubber feet may be more like less perfect couplers than really decouplers. For something to decouple it's gotta float the object on some kind of air or fluid or some substance that converts any movement to heat or something, it if its a substance like that it has to be of the proper density for the weight it's carrying because if it just squishes down, then it's also coupling and not decoupling.
     
  20. chervokas

    chervokas Forum Resident

    The idea when spikes first kind off became the audio vogue years ago the idea was that you were creating a kind of mechanical drain for energy from the component into the surface below.
     
  21. Stephen Syli

    Stephen Syli Well-Known Member

    Location:
    Rivington UK
    I'd go with the cock up theory of history, as a key factor being considered at the time was a stable platform to avoid speaker movement. Certainly in the UK a level floor is either a newish house or a relaid floor. Ideas about mechanical energy having a detrimental effect on components, was in the future. Of course then it meant that if it didn't come with spikes, it wasn't coming from a real HI-FI company.
     
  22. Erik Tracy

    Erik Tracy Forum Resident

    Location:
    San Diego, CA, USA
    Another decouple proponent.

    Epik 15" Valor sealed sub on a wood floor - deep but a bit sloppy.

    Mounted on a Auralex SubDude platform - beautifully clear and articulate bass.
     
    33na3rd likes this.
  23. Dream On

    Dream On Active Member

    Location:
    Canada
    First off, let me just say that I have no idea what I'm talking about.

    But, on the surface, I would think you'd want to couple a sub/speakers and decouple other components. Subs and speakers produce a lot of energy and vibrations, so it would make sense to me that you'd like to quickly funnel these away from the speaker where they would have less impact on the next note produced. I figure this is why basically every stand I've encountered uses spikes, as does every floorstanding speaker and sub.

    In contrast, sources and amps don't produce the same energy that speakers do, so it would make sense that you'd want to decouple them. There will be a lot of energy in the room (produced by the speakers and sub) and you would probably want to try to ensure most of that does not go back into the component.
     
  24. audiorocks

    audiorocks Active Member Thread Starter

    Location:
    California
    Sure makes sense to me.

    I haven't had a chance to try the rubber feet instead of spikes on my sub yet but I did remove the front grill and that made a big improvement. I can honestly say that it sounds totally "right" now. Not to say that it can't be improved but nothing bothers me about the sub's performance at this point.
     
    Waxfreak likes this.

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