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advise Pleeeease!

Discussion in 'Subwoofers' started by DonMaico, Jul 5, 2004.

  1. DonMaico

    DonMaico
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    Just took receipt of my BK sub and to say that the instructions are rudimentary would be an understatement. tried to ring them but they are on their hols until the 19th so I would appreciarte some advce . first of all its the connection bit . I have a high level input which I am being told to connect amplifier output - I presume this must mean that the amps own power output wopuld be used and the sub would be passive. Then there is a low level connector which consists of a pair of rca jacks. unfortunatel the back of my amp only sports ONE jack for sub connection and I am assuming this must be for coax cable. Does this mean I need an adaptor of sorts?
    There are also four knobs- high and low level gain ,freq. and phase for which instructions give a very short description and thts it . They obviously expect users to know exactly how these things work already and not be a complete numbskull novice like me :mad: :( Please help!
     
  2. Philly112

    Philly112
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    Right, IanJ will probably correct me, but here we go!
    The connections look to be the same as for Rel subs.
    To make things easy, just connect the low level from the amp to ONE of the low level inputs on the sub. Its best to use a proper sub cable as they need to be well screened. On my Rel's the two inputs have different gains - see if you can hear a difference with yours and use the loudest one.
    Low level gain is then basically the volume control for the sub.
    The frequency knob is to set the crossover frequency. You will probably be using the cross over frequency in the amp (probably 80Hz for THX amps, but it may be different, or even customizable).
    If this is the case, set the frequency on the sub to its highest point - so if its at say 120Hz and the amp is only outputting below, say 80Hz, you won't miss any signal.
    The phase has two possibilities - just see which one gives the most bass (although damned if I can hear any difference on mine!)
    That should do it I hope - oh, and you'll probably want to set your speakers to small in the amp, but without knowing what kit you have I can't really comment on this.
    And don't worry about being a numbskull - its just one step behind me!
    If you're ever stuck, just have a look at the SVS website (and maybe Rel's). There's lots of good advice on integrating subs, placements etc, and I think you can also see their manuals which are well written - most sub controls are the same anyway so you could use one of their manuals!
    Finally, if you follow the above and it all blows up, you can buy my spare Rel in the classifieds!!!
     
  3. IronGiant

    IronGiant
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    If you had no sub out you could send a full-range stereo signal to both low level connectors and use the sub to do the filtering. In your case you only need to connect your amps sub out to one low level input (usually the left).

    The high level you can connect to your main speaker connectors on the amp and the sub panel filters out the bass and sends it to its amp (ie it's still an active sub). Red to Right + (red) yellow to left + (red) and black to a negative (black- again usually the left if I'm not mistaken). It's only worth using the high level connection if your main speakers are set to large. Many people set their main speakers to small and just use the low level input.
    I don't have that specific BK panel so someone else may be able to help with the settings.
    HTH

    Dave

    Dave
     
  4. DonMaico

    DonMaico
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    Many thanks both of you for your prompt reply . Looks as tho i'll be doing a little bit of experimentation tonight. iunciudentally my speakears are KefQ55, Q85c , 55s and my reciever is a Harman Kardon 5500( not thx). I'll use the left hand rca socket as you suggested( wonder why they put a pair in as if it was left and right?) and set the speakers to small.Then its a question of setting the right crossover. Wish me luck as I cannot afford to blow this sub ; Ive alredy had one bollocking from the misses! she is threataning to buy a horse. :oops:
     
  5. IronGiant

    IronGiant
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  6. DonMaico

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    it was suggested to me that I set the amp at 100Hz and sub freq knob at 90 Hz. looking at the knob it has only two figures 40 and 120 so I set it somewhere near 120 ( two lines from ) thinking that would be nmear enough.which position would you set it at ,Dave?
    Gain I have at 12 o'clock and phase I cannot figure out the purpose of . My next decission will be position and whether to site it on a concrete slab as I have wooden floorboards. The sound I get is rather boomy at the moment especially on Logic 7 ( I have an HK amp) so I am assuming that is to with the floorboards . My most favoured sitec would be facing fronspeakers about 3 mtrs from and under rt rear sat.- but that would be in a corner . The next site could be under left rear sat again 3mtrs from fronts, and lastly nearer left front speaker but to one side and not near a corner.I shall have to experiment. any way thanks very much for your response. :thumbsup:
     
  7. Dfour

    Dfour
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    I find the best way to set the sub up is to set the phase at 0 degrees. the crossover at max and use the amps crossover to set it to approx 80hz.

    The best position is to play something bass heavy with the sub in your listening position and then walk arround the room listening room to find out where the bass sounds the best and then put the sub there.

    Put it on a slab and put a slab on top of it for the best results.:D
     
  8. DonMaico

    DonMaico
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    sounds like a good idea- concrete sandwich
     
  9. DonMaico

    DonMaico
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    Well I think I've got the hang of it now so I want to thank all you guys as you have been a lot of help. The sub is excellent but I think I shall get in touch with BK about their sub GCSE instruction leaflet. I am somewhat confused about the wiring diagram at the back - like why include it???Tells me not to connect to to a speaker with a lower load than 4 ohms. Why would I want to do that?? Its already got a speaker! ????
     
  10. Stereo Steve

    Stereo Steve
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    I personally find that if I set the xover on the sub so that it's invading the mains' territory then the whole thing turns to mush. Maybe because I have a fairly capable set of mains and they are in corners (I know, I know). So, I set the xover at 80 on the amp and 80 on the sub and then back it off by ear until the bass ceases to conflict. This gives me a nice tight, clean sound for music. I gernerally find that doing this, the sub xover ends up around 70hz.
     
  11. DonMaico

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    Ok I'll try that Steve . At the momnet I have the sub full on at 120 and the amp at 100 - havent detected any mush tho.My speakers (Kef q55s) are not fussy about placement although they are not in a corner. Have detected some buzzing coming from somewhere tho.
     
  12. IronGiant

    IronGiant
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    If your BK panel is equivelant to mine: if you turn the frequency response all the way over to the right you will get a click from the knob which turns off the internal frequency filtration and lets a full range frequency response through, hopefully managed by your av amp so it only sends low signals. This is intended to take full advantage of the 0.1 track in DD and DTS.

    This is the best option if you trust your av amp to do the bass management.

    Dave

    EDIT: Ultimate slab sandwich:

    My sub is on spikes which effectively anchor it to to the concrete slab the whole house is built on, and it has a slab of granite on top. Even at sensible listening levels it is quite capable of getting the concrete floor vibrating.
    Dave
     
  13. DonMaico

    DonMaico
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    Ty Dave
    At which freq do you have your amp set up 80hz , 100 hz?Presumably you have it set at small as well? I tried the high level input with the cable provided and connected to the right/ left red speaker connectors and the black at one of the black connectors but the sound vibrated alarmingly so I have reverted to low level.
    When one of the previous posters suggested a concrete sandwich I thought he was joking. I can see that putting on a slab may work - I have wooden floorboards and this seems to result in a rather boomy bass. :thumbsup:
     
  14. Ian J

    Ian J
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    If you have KEF Q55 I would suggest setting the speakers in the amp to small and the crossover in the amp to 80Hz.

    After you have tried that you can then fiddle with the settings to see what suits you better.

    Boominess is probably a positioning problem. Try bringing it away from the corner or wall to see whether it reduces the boom.
     
  15. DonMaico

    DonMaico
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    Ty Ian
    Itried the high output option setting the speakesr at large but the sub vibrated alarmingly so I gave that one up. I think ordering a decent cable from Mark Grant would be a good idea. at the moment I have the sub away from corners beacuse I have no option - the supplied cable is too short- but I find keeping the gain low helps with the boominess( about 10'clock on the dial). i'll probably have a chat with Bk about it when they return from their hols. As I have never heard a sub before I am not sure what to listen for . I am thinking bass should sound crisp and definite not elongated- if you get my drift.
     
  16. IronGiant

    IronGiant
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    My amp is set at 80Hz (no other option) and I'm using a Mark Grant cable.

    Dave
     
  17. DonMaico

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    Tried the Freq knob all the way to the right but I get a humming noise coming from the sub which increases as I turn the gain knob up :confused: :confused:
     
  18. IronGiant

    IronGiant
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    Ouch, that doesn't sound good. You may have an earth feedback loop, do a search on this site for possible solutions.

    If you don't have the LFE clickover setting, then I'd certainly back the frequency response back down to around 80Hz. This may well require guesstimation, depending on how your panel is labelled.

    dave
     
  19. DonMaico

    DonMaico
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    ASctyually I was wrong , Dve it doesnt get worse as i turn the gain knob up - stll audible tho.Perhaps I should get in touch with BK upon their return.Maybe its to do with the cheap cable provided - ie unscreened bellwire.
     
  20. DonMaico

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    Sorry Typonese is getting worse! Actually I was wrong , Dave, :oops:
     

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