Page 3 of 3 FirstFirst 123
Results 21 to 27 of 27

Thread: F25

  1. #21
    Join Date
    Apr 2014
    Posts
    455

    Default Re: F25

    At first I thought that this sounded crazy, that you are having this problem in a small sealed room, like you have. But, if you listen at 75 dB, for example, then the soundtrack can call for up to 105 dB peaks from the subwoofer on a movie soundtrack. The most detailed measurements of what the F12 should be close to in terms of measurements are here: http://www.hometheatershack.com/foru...ealed-56l.html. Many modern soundmixes for action movies contain a significant amount of content below 40 Hz. You should get a lot of room gain in this room to extend some of the curves in the long term output compression extend flatter to maybe even below 20 Hz, in your room, or maybe even be slightly elevated as you go down into these lower frequencies. But, it is probably not likely on the 105 dB sweep when you get down into the low 20 Hz range. So if you have peaks that are surpassing 105 dB it seems reasonable that you might bottom out the driver. The problem is even worse if you are usually listening at 85 dB (reference volume). How loud do you listen to your movies typically?

    If you are not listening soundtracks at anywhere near 75 dB, 80dB, 85 dB and up (on your receiver volume dial), then I think that Johnny Mac is right and you should call Rythmik. If you do listen that loud, then you likely need a larger sub. Just don't surpass 85 dB as a usual volume level, since you are then bordering on possible hearing damage.
    Last edited by N Boros; 08-16-2016 at 01:52 PM.

  2. #22
    Join Date
    Aug 2003
    Location
    Manhattan Beach, California
    Posts
    7,032

    Default Re: F25

    It's a square room, so he has lots of cancellations.
    -curtis

  3. #23
    Join Date
    Dec 2008
    Posts
    72

    Default Re: F25

    Quote Originally Posted by Johnny_Mac_III View Post
    Hmmm....the F12 shouldn't even be breaking a sweat with that room size at reference level. Call Rythmik.
    I have sent the subwoofer back to Jim Salk , he tested it and gave it a clean bill of health , even adjusted the setting for me , I only have trouble with movies , not music , the driver or cone bottoms out or clips on sudden explosions and such , I play loud but not over the top , below reference I would say
    Bunch of speakers

  4. #24
    Join Date
    Dec 2008
    Posts
    72

    Default Re: F25

    Quote Originally Posted by N Boros View Post
    At first I thought that this sounded crazy, that you are having this problem in a small sealed room, like you have. But, if you listen at 75 dB, for example, then the soundtrack can call for up to 105 dB peaks from the subwoofer on a movie soundtrack. The most detailed measurements of what the F12 should be close to in terms of measurements are here: http://www.hometheatershack.com/foru...ealed-56l.html. Many modern soundmixes for action movies contain a significant amount of content below 40 Hz. You should get a lot of room gain in this room to extend some of the curves in the long term output compression extend flatter to maybe even below 20 Hz, in your room, or maybe even be slightly elevated as you go down into these lower frequencies. But, it is probably not likely on the 105 dB sweep when you get down into the low 20 Hz range. So if you have peaks that are surpassing 105 dB it seems reasonable that you might bottom out the driver. The problem is even worse if you are usually listening at 85 dB (reference volume). How loud do you listen to your movies typically?

    If you are not listening soundtracks at anywhere near 75 dB, 80dB, 85 dB and up (on your receiver volume dial), then I think that Johnny Mac is right and you should call Rythmik. If you do listen that loud, then you likely need a larger sub. Just don't surpass 85 dB as a usual volume level, since you are then bordering on possible hearing damage.
    I think the 12" sub does not have the headroom I need for movies , everything else about the sub is fantastic , Will I loose sound quality going to a larger sealed sub ?
    Bunch of speakers

  5. #25
    Join Date
    Jan 2015
    Posts
    132

    Default Re: F25

    Like Curtis said, the room has alot of cancelations. This could be contribute to the sub sounding like it doesn't have enough headroom due to the dips in the frequency response. IMO getting a more powerful sub won't solve this. Adding another sub would be more benificial. The first step in this process would be to buy a mic from Cross Spectrum and use REW to better diagnose the issues. Or just download REW and use the room sim feature and see what adding another sub and/or moving the seating position would do. Room sim has been pretty accurate for me.

  6. #26
    Join Date
    Aug 2003
    Location
    Manhattan Beach, California
    Posts
    7,032

    Default Re: F25

    Quote Originally Posted by Johnny_Mac_III View Post
    Like Curtis said, the room has alot of cancelations. This could be contribute to the sub sounding like it doesn't have enough headroom due to the dips in the frequency response. IMO getting a more powerful sub won't solve this. Adding another sub would be more benificial. The first step in this process would be to buy a mic from Cross Spectrum and use REW to better diagnose the issues. Or just download REW and use the room sim feature and see what adding another sub and/or moving the seating position would do. Room sim has been pretty accurate for me.
    This!

    Sorry I did not respond more...I was at work and responding on my phone, which is a pain to do.

    Take some measurements and see what is going on. 11 x 11 x 9 is a small room...I don't think you should be bottoming out the sub.
    -curtis

  7. #27
    Join Date
    Apr 2014
    Posts
    455

    Default Re: F25

    Quote Originally Posted by qwknuf6 View Post
    I think the 12" sub does not have the headroom I need for movies , everything else about the sub is fantastic , Will I loose sound quality going to a larger sealed sub ?
    I want to answer some of your questions that haven't been asked, but first we need to make sure you are not buying a subwoofer you don't need. The F25 will blend just as well with your speakers as the F12 did. Your not going to lose any sound quality going with it over the F25 over the F12. But it may be that the Sierra 2s don't have the output capabilities of the F25. This is something I would talk with both Dave and Brian about.

    We know your room size. We need to know more to be able to tell you what is going on. What volume level do you typically have your receiver set at when you run into bottoming out the subwoofer? If you have an spl meter, what are the dBs when you bottom out the driver?

Posting Permissions

  • You may not post new threads
  • You may not post replies
  • You may not post attachments
  • You may not edit your posts
  •