My Mid Q Sealed Tempest response...

Discussion in 'Home Theater Projects' started by Alex_P, Mar 15, 2004.

  1. Alex_P

    Alex_P Stunt Coordinator

    Joined:
    Nov 3, 2003
    Messages:
    133
    Likes Received:
    0
    Here are the numbers of my tempest response.
    20hz - 90db
    25hz - 91db
    30hz - 93db
    35hz - 103db
    40hz - 104db
    45hz - 107db
    50hz - 107db
    55hz - 107db
    60hz - 106db
    65hz - 101db
    70hz - 108db
    75hz - 108db
    80hz - 106db
    85hz - 102db
    90hz - 101db
    95hz - 100db
    100hz - 103db
    100hz - 103db
    110hz - 103db
    120hz - 92db
    130hz - 96db
    140hz - 103db
    150hz - 101db

    Note: At 30hz point and on when I try to play sine tones at reference level, due to violent shaking in my apartment I have to lower down the reciever volume to 10db. So at 30hz the actual response is 83db and I add 10db.

    According to the numbers, is my sub normal? I saw a lil dip of 10db at 120hz and was wondering if I can flatten that out using my old Kenwood Equalizer? The range on the Kenwood EQ is 60hz - 15khz. I'm guessing that if I use the Kenwood EQ, it will not help boosting the any freq below 60hz right? Or is it by flatten out the response curve at higher freq will also help out the low freq? Any suggestions will greatly appreciated. I'm still trying to maximize my sub output without spending much money. Don't get me wrong, my sub sounds awesome in movies/music. Just like someone here said "the upgrade bug has just bitten me..."

    Link to pics of my sub
    My Mid Q Sealed Tempest

    Thanks
    Alex,
     
  2. Brian Fellmeth

    Brian Fellmeth Supporting Actor

    Joined:
    Jul 30, 2000
    Messages:
    789
    Likes Received:
    0
    Your sub is normal. Your room is normal. You need a BFD.
     
  3. Alex_P

    Alex_P Stunt Coordinator

    Joined:
    Nov 3, 2003
    Messages:
    133
    Likes Received:
    0
    Thanks for the reply Brian. How much improvement will the BFD make? Will I see a big improvement on my sub? Is there any alternative options to improve my sub response without spending more than $50?

    Thanks
    Alex,
     
  4. Wayne Ernst

    Wayne Ernst Cinematographer

    Joined:
    Feb 24, 2002
    Messages:
    2,588
    Likes Received:
    0
    Alex,

    In regards to Brian's response, the recommendation of the Behringer Feedback Destroyer (approx. $115) is one of the best moves an owner of a subwoofer can make. The BFD allows you to dial in the frequency that you want to "adjust." There is lots of great sites on the BFD - I couldn't believe how much there was until I started searching. Also, some of the older posts have great information on the BFD, too.

    While you do have a price-point of $50 or so that you'd like to spend on resolving some issues - you might be better saving your lunch money for a few more weeks (hey, that's what I do [​IMG] ) and get the BFD.
     
  5. Brian Fellmeth

    Brian Fellmeth Supporting Actor

    Joined:
    Jul 30, 2000
    Messages:
    789
    Likes Received:
    0


    That depends on whats important to you. For movies, I don't think it matters much if the FR is a little ragged. The main benefit is music where the BFD will eliminate the problem of some bass notes jumping out of the music and others receeding. If you can't hear this effect or don't care, then its not worth the $120.
     
  6. Wayne A. Pflughaupt

    Joined:
    Aug 5, 1999
    Messages:
    6,098
    Likes Received:
    33
    Location:
    Katy, TX
    Real Name:
    Wayne
    Take a look at what the BFD did for Sonnie Parker, the guy who created of the BFD Comprehensive Set-Up Guide


    [​IMG]


    Brian is generally right that equalizing is more important for music than subs, since bass in movies is mostly explosions and stuff like that. However, I’ve heard people say they were hearing more detail in the “boom” than they were before,when their overall sub sound and level was essentially determined by the hottest peaking frequency.

    Bottom line, for movies or music you can’t go wrong EQing – unless like Brian said, you just can’t hear that some music bass notes are hotter than others. [​IMG]

    Regards,
    Wayne A. Pflughaupt
     
  7. Alex_P

    Alex_P Stunt Coordinator

    Joined:
    Nov 3, 2003
    Messages:
    133
    Likes Received:
    0
    Thanks all,

    I have more questions [​IMG] Will BFD boost up LFE response? My sub response at 20hz now is 90db. Can I use BFD to boost it to 95db or so? If BFD can do that, how much can it boost or what is the recommended?

    Thanks
    Alex,
     
  8. Wayne Ernst

    Wayne Ernst Cinematographer

    Joined:
    Feb 24, 2002
    Messages:
    2,588
    Likes Received:
    0


    It really shouldn't be used to provide a "boost" in this manner - not that it would be able to anyway. However, the intention is to "level out" some of the frequencies. If you have a slight dip @ 28Hz, then you could use it to provide the proper correction.

    If you're looking to boost the output, then consider another amp. However, keep in mind that if you are looking to get 5dB more out of the combination, it's going to take a much bigger amp. Finally, cabinet designs can make up for some of the power - efficient designed cabinets (of great size) will be more efficient, in most cases, than smaller cabinets.
     
  9. Jeff Braddock

    Jeff Braddock Second Unit

    Joined:
    Jan 26, 2002
    Messages:
    306
    Likes Received:
    0
    Alex,
    How did you finish your sub? I am prob. going to go with bedliner and it appears that you did too. Did you prime or paint it before applying your final finish? Thanks.
     
  10. Alex_P

    Alex_P Stunt Coordinator

    Joined:
    Nov 3, 2003
    Messages:
    133
    Likes Received:
    0
    Jeff,

    On the finish, I first sand it using 300 grits sand paper. Then I apply a sealer coat to help avoid MDF from soaking up all the paint. I then wet sand it using 400 grits sand paper. Then I apply a cheap black spray paint from Walmart. Wet sand it using 400 grits sand paper again (be sure not to sand off all your paint). Then I apply the truckbed liner finish. Just have to be carefull not to aim it to close else you will have wet run-on. It looks pretty nice. I'm happy w/ the finish. My girlfriend was impressed hehehe that I can complete a sub nicely [​IMG] The only thing though, she nags and nags when I work on the wood... I told her that when I completed my sub I will crank up the volume so that I can't hear your nagging anymore hehehe...

    Good luck with your finish Jeff...[​IMG] Let me know if you need help more info regarding on the finish or anything... I kinda when through it and actually enjoy the whole building process... pretty cool looking back...

    Alex,
     
  11. Alex_P

    Alex_P Stunt Coordinator

    Joined:
    Nov 3, 2003
    Messages:
    133
    Likes Received:
    0
    Guys,

    One more question, if I decide to upgrade my amp to let say 500W. How much more output can I expect from it? At 20hz, my sub produce 90db as of now. With 500W amp, how much can it be?

    Thanks
    Alex,
     
  12. Jeff Braddock

    Jeff Braddock Second Unit

    Joined:
    Jan 26, 2002
    Messages:
    306
    Likes Received:
    0
    Thanks Alex. I wasn't trying to derail the thread, I was just curious about the finish.
     
  13. Wayne Ernst

    Wayne Ernst Cinematographer

    Joined:
    Feb 24, 2002
    Messages:
    2,588
    Likes Received:
    0
    Alex,

    3dB would be gained by doubling the amp power (250 -> 500 watts.) If you're considering going to such a powerful amp, consider a pro audio amp where you'll get more "bang for your buck."

    Some pro audio amps to look at:

    - QSC
    - Behringer
    - Crown

    ... And others

    If you're looking for a cheaper pro audio amp, check out the Nady amps from Musicians Friend where they have some great prices on them. I personally have the XA-1100 which is a pretty good amp. Most of the pro audio amps might require a cooling fan replacement if you're sensitive to extra noise or if you can't tuck the amp in an area to quiet it a bit. However, most use 80mm fans which are readily available for $10 or so at most computer stores.
     
  14. Alex_P

    Alex_P Stunt Coordinator

    Joined:
    Nov 3, 2003
    Messages:
    133
    Likes Received:
    0
    Thanks Wayne. I already cut a hole for the plate amp. If I'm getting a pro amp like Crown/QSC, how would I going around this? The hole is there and I believe pro amp is stand alone kind of amp, I then would have to patch that hole up? Thanks.

    Alex,
     
  15. Wayne Ernst

    Wayne Ernst Cinematographer

    Joined:
    Feb 24, 2002
    Messages:
    2,588
    Likes Received:
    0
    Alex,

    You are correct in your assumption - if you do use a plate amp, you'd have to do a little patching. However, the 500 watt plate amp could be of different dimensions requiring a little modification also. I just suggested the pro audio amp because they are fairly economical when it comes to power and the amount you pay for them.
     
  16. Alex_P

    Alex_P Stunt Coordinator

    Joined:
    Nov 3, 2003
    Messages:
    133
    Likes Received:
    0
    Appreciated your input Wayne... Today I just move my sub to a different corner and I check the SPL measurement again. I saw a 3db increase on my meter, just awesome. Then I pop in Fight Club and watch the last scene where those buildings collapsing at -8db below reference. WOOOOOOOOOOOW..... just shake my whole apartment. I'm just shocked at how much bass it has on that movie... I'm just going to hold on on that BFD/amp upgrade... Good enuf for me now... I'm pretty sure I'll upgrade soon [​IMG] Don't know why is it that I keep wanting more and more bass...

    Alex,
     

Share This Page