• 05-11-2011, 10:55 AM
    dingus
    subwoofer... passive or powered?
    which is the better performer in terms of accuracy, or is it a moot point?

    i'm considering adding a dedicated sub that can get down in the mid-20hz. my receiver should be able to drive a passive sub without problem, and if not i have some beefy power amps that can do the job without question. my ht rig is a music first system, so i prefer sound quality over quantity.
  • 05-11-2011, 11:29 AM
    pixelthis
    1 Attachment(s)
    Quote:

    Originally Posted by dingus
    which is the better performer in terms of accuracy, or is it a moot point?

    i'm considering adding a dedicated sub that can get down in the mid-20hz. my receiver should be able to drive a passive sub without problem, and if not i have some beefy power amps that can do the job without question. my ht rig is a music first system, so i prefer sound quality over quantity.

    Most subs are powered these days. THERES something called a "plate amp" on
    the back, and most of these are quite good.
    My sub came with a 600w amp, which died when a friend borrowed it, so I
    canabalized another sub for its 130w amp, which works fine in my small room.
    If you really want a power amp or something else to power a sub, you can buy a
    kit and build your own, and power it anyway you want, or buy a sub and take the amp off of the back.
    But it will give little if any improvement over the plate amp that comes with most subs,
    just complicate the plumbing, is all.:1:
  • 05-11-2011, 11:48 AM
    markw
    You're gonna have to figure on a low-pass filter (at least) somewhere in the mix.
  • 05-11-2011, 12:29 PM
    GMichael
    Both can get you very nice results. I built a passive sub and mated it with a 4000 watt external amp. It works great. But I've also heard some very nice subs with the plate amps built in.
    The build quality will make the bigger difference.
  • 05-11-2011, 12:30 PM
    bfalls
    I would recommend powered over passive. I don't know of any receivers which have a powered output for a sub. Connecting a passive sub to a receiver would require connecting your mains via the sub's speaker level inputs, thus sharing the power from the main channels with the sub.

    Having a powered sub would reduce the strain on the main channels and free up power for mid and high freq reproduction. Especially if you are considering a sub which can reproduce appreciable levels in the 20Hz-30Hz range which takes a low of power.

    Most receiver can't even produce rated output with all channels driven. Adding a sub to the mix would reduce the available power to all channels that much more. Unless you have a flagship receiver weighing 45+lbs (due mostly likely to a larger transformer) and 120+W/ch go with a powered sub. If you're a bass guy who likes bass very low and very loud go with a good powered sub.

    If you can't swing the cash for a good powered sub. You can still get decent bass with a lesser one and utilize corner placement. From what I've read, corner placement can increase perceived output by 6 - 9 db.
  • 05-11-2011, 12:56 PM
    GMichael
    Yeah, I wouldn't drive the sub with your receiver's amp. You'll want another amp. Either a built in one or external will work.
  • 05-11-2011, 02:46 PM
    Sir Terrence the Terrible
    Quote:

    Originally Posted by bfalls
    I would recommend powered over passive. I don't know of any receivers which have a powered output for a sub. Connecting a passive sub to a receiver would require connecting your mains via the sub's speaker level inputs, thus sharing the power from the main channels with the sub.

    Having a powered sub would reduce the strain on the main channels and free up power for mid and high freq reproduction. Especially if you are considering a sub which can reproduce appreciable levels in the 20Hz-30Hz range which takes a low of power.

    Most receiver can't even produce rated output with all channels driven. Adding a sub to the mix would reduce the available power to all channels that much more. Unless you have a flagship receiver weighing 45+lbs (due mostly likely to a larger transformer) and 120+W/ch go with a powered sub. If you're a bass guy who likes bass very low and very loud go with a good powered sub.

    If you can't swing the cash for a good powered sub. You can still get decent bass with a lesser one and utilize corner placement. From what I've read, corner placement can increase perceived output by 6 - 9 db.

    B, this is not correct. You use the LFE output directly to an amp which amplifies the signal to the speakers. All of my H-PAS subs are passive, and that is how I hook them up

    Processor's> LFE output > Audyssey sub EQ > amp to speaker.

    I do not think either passive or active subs offer any advantage over the other. I use both types, and get great sound from both types. Calibration and room placement are more important than active or passive.
  • 05-11-2011, 03:39 PM
    Poultrygeist
    I have an outdoor passive sub which is driven off the amp speaker taps ( speaker level connection ), The sub then passes the signal on to two sat speakers which run full range.

    I'm building two 15 " H frame OB bass drivers which are passive in the sense that they are externally powered by a Dayton APA150 stereo amp which has it's own crossover control.
  • 05-11-2011, 04:12 PM
    bfalls
    Quote:

    Originally Posted by Sir Terrence the Terrible
    B, this is not correct. You use the LFE output directly to an amp which amplifies the signal to the speakers. All of my H-PAS subs are passive, and that is how I hook them up

    Processor's> LFE output > Audyssey sub EQ > amp to speaker.

    I do not think either passive or active subs offer any advantage over the other. I use both types, and get great sound from both types. Calibration and room placement are more important than active or passive.

    My bad. I misread. I thought he wanted to go directly from his receiver. I use a similar config with my passive ACI Saturn compound sub, LFE out, Yamaha M-65 amp, sub with one system. Also to bi-amp my Legacy Focus' 3-12" woofers. UMC-1 LFE out, XPA-5, sub.
  • 05-11-2011, 04:24 PM
    dingus
    the receiver is the Pioneer in my sig, a 7.1 x 130wpc @ 8 ohm, 160wpc @ 6 ohm. even if that wont do it i can use one of my Yamaha amps, B-2x (170wpc) or M-2 (210wpc). even so, i wouldnt be opposed to a powered sub.

    Quote:

    Originally Posted by Sir Terrence the Terrible
    Calibration and room placement are more important than active or passive.

    thats good info. i've never used a separate sub before. i got used to having all the bass i could handle with the 4x12" woofers in a pair of AR9's. what about ported -vs- acoustic suspension?
  • 05-11-2011, 08:58 PM
    harley .guy07
    There are plenty of subwoofers available that can fill a large room that cna go in your corner or otherwise. SVS is one I would recomend. also Hsu subwoofers are a good company from what I have read. You can build your own custom sub in your home it just takes the nohow in the driver selection,amp,and enclosure that you want to use. I once installed a trio of EV 18" subs with a QSC amplifier running 2 ohm with fan cooling in a guys basement and it was thunderous but he would turn them off for music which I don't blame him they were not meant for that anyway. My point is that the amount of bass you produce is not the quest it is how well and how detailed you can do it without disrupting the sonic flow from your main speakers and that they meat at grounds that you you cannot tell one from the other. That is the ultimate test of a sub, most cannot do it in that they put out something that gives them away like a sonic signature or a difference to the mains. Buts thats for music home theater is a different battle all together.
  • 05-12-2011, 01:05 PM
    pixelthis
    Quote:

    Originally Posted by GMichael
    Yeah, I wouldn't drive the sub with your receiver's amp. You'll want another amp. Either a built in one or external will work.

    THERES' nothing wrong with it, an amp is an amp.
    BEFORE I replaced the plate amp on my sub, I used one of the spare channels
    on my receiver to power my sub. WORKED fine, but you are correct in that it
    is not the preferred way of doing things. A good patch in a pinch, tho.
    ALSO, no reason you can't use an external amp to power a sub, just a waste of a decent amp, is all.
    A PLATE AMP IS DESIGNED to drive a sub, and it just works a lot better.:1:
  • 05-12-2011, 01:16 PM
    pixelthis
    1 Attachment(s)
    Quote:

    Originally Posted by dingus
    the receiver is the Pioneer in my sig, a 7.1 x 130wpc @ 8 ohm, 160wpc @ 6 ohm. even if that wont do it i can use one of my Yamaha amps, B-2x (170wpc) or M-2 (210wpc). even so, i wouldnt be opposed to a powered sub.


    thats good info. i've never used a separate sub before. i got used to having all the bass i could handle with the 4x12" woofers in a pair of AR9's. what about ported -vs- acoustic suspension?

    A "PORTED" sub tends to produce a "huffing" sound as it pumps air in and out of its port, although this isn't a problem most of the time, but on a poorly designed sub it can
    be a bother.
    MAKING speakers is the last bastion of audios roots, which started out with kits to
    build amps, etc. AND its fun, but mostly a waste of time, really.
    A sub already built is just going to work a lot better. Only reason I messed with mine
    is that I really love my sub, it is very musical, and besides, if you can fix something
    that is a 1200$ item instead of chucking it, you do so.
    Mine is either a clone or a copy of a BOB carver mini sub, don't think you could easily
    replace it, not very cheaply, anyway.
    AS FOR PORTED vs sealed enclosure, I prefer the sealed type, just easier to place,
    IMHO.:1:
  • 05-27-2011, 02:31 PM
    N. Abstentia
    Your receiver will never be able to power a sub properly. Get a powered sub, or an outboard amp if you get a passive sub.
  • 05-28-2011, 12:09 PM
    dingus
    i just pulled the trigger on an M&K V-1b, 12" powered sub. its a sealed enclosure and seems to be integrating nicely into the system so far. still a little bit of tweaking left to do before i'm totally happy with it.
  • 05-28-2011, 01:05 PM
    GMichael
    Next step is a BFD. For under $100 it's a huge addition to any sub.
  • 05-28-2011, 02:34 PM
    dingus
    whats a BFD?
  • 05-28-2011, 06:20 PM
    GMichael
    It's made to be a feedback destroyer to prevent feedback at live shows. But it turns out to be a great EQ for subwoofers as well.
    Check this link for a better explanation.
    http://bfdguide.ws/
  • 05-28-2011, 07:59 PM
    dingus
    ah yes, thank you!
  • 05-29-2011, 09:17 AM
    pixelthis
    1 Attachment(s)
    Quote:

    Originally Posted by N. Abstentia View Post
    Your receiver will never be able to power a sub properly. Get a powered sub, or an outboard amp if you get a passive sub.

    AU CONTRAIR, an amp is an amp, and my receiver is (or was)
    7.1 and my system 5.1. I RAN my sub off of one of the spare amps
    for months, until another plate amp availed itself to me.
    My receiver was 125wpc, and I didn't need nearly that much in
    my small listening room, NEVER had a problem, and again, it is not the optimum way to go, I AGREE WITH YOU, but it is not bad
    in a pinch.:1:
  • 05-29-2011, 06:06 PM
    N. Abstentia
    Yeah I didn't say it couldn't be done...I just said it couldn't be done right!
  • 05-30-2011, 04:20 PM
    pixelthis
    Quote:

    Originally Posted by N. Abstentia View Post
    Yeah I didn't say it couldn't be done...I just said it couldn't be done right!

    It can be done in a way that works, which is always "right"
    even if sometimes not optimum.
    IN ALL THE TIME I ran a sub like this I never had a problem.:1:
  • 05-31-2011, 05:14 AM
    GMichael
    Quote:

    Originally Posted by pixelthis View Post
    It can be done in a way that works, which is always "right"
    even if sometimes not optimum.
    IN ALL THE TIME I ran a sub like this I never had a problem.:1:

    But the OP was asking which was better. Using the amp in your/his receiver is surely not the better choice, unless he has no choice.
  • 05-31-2011, 11:27 AM
    pixelthis
    1 Attachment(s)
    Quote:

    Originally Posted by GMichael View Post
    But the OP was asking which was better. Using the amp in your/his receiver is surely not the better choice, unless he has no choice.

    By all rights this method should be like one of those tire fix
    spray cans, because when a sub goes out its not always
    convenient
    HOWEVER days turned into months, and this "fix" worked fine
    THE truth is that a sub is probably never going to need even
    the paltry 125watts put out by my receiver channel . And levels,
    etc were easy to adjust.
    And this was a sub that came with a BASH 600w plate amp(its
    now running on a 130w). It may go against instincts, but at the end of the day, an amp is really just an amp.
    I know that the true power of a receiver is gaged by its power
    supply, how many amps is available to be distributed to each
    channel, and the power claims are usually about as optimistic
    as TREASURY forecasts, but I REALLY NEVER HAD A PROBLEM.:1:
  • 05-31-2011, 11:40 AM
    GMichael
    Would you rather drive cross country with a tire that has a can of fix-o-flat in it or on 4 new tires? Sure, you may never have a problem with that tire, but if you had a choice, which would you pick?
  • 06-01-2011, 01:43 PM
    pixelthis
    Quote:

    Originally Posted by GMichael View Post
    Would you rather drive cross country with a tire that has a can of fix-o-flat in it or on 4 new tires? Sure, you may never have a problem with that tire, but if you had a choice, which would you pick?

    Spoken like a true middle class person who only has to open a
    checkbook to buy anything.
    If you use a can of "fix flat" you can get that tire plugged for fifteen
    bucks or less. QUITE often the price of four new tires is out of reach,
    so its not even an issue.
    As much as I ENJOY THIS HOBBY, there is always something
    more pressing. In an age when gas for work is 160 a month,[I]plus[/I
    the gas to get around, with groceries costing a small fortune,
    if something is working I tend to not mess with it.
    THERE are targets of opportunity, like 29 bucks for a hundred dollar tuner, an EMO AMP FOR 250 BUCKS(haven't seen it that
    cheap again).
    RUNNING my sub on a receiver channel worked fine, didn't bother
    me at all, didn't hurt the sub, not the first time I have done it.
    And if I had not had a plate amp fall into my lap, I would be probably still be set up that way.
    BEING type two diabetic I need pills just to protect my kidneys.
    Pills and test strips, hundreds of dollars a month, visits to the
    doctor every three months. You can't get kidneys at RADIO
    SHACK.
    I DO HAVE a meager HT "budget" but you have to prioritize,
    and if something works you don't mess with it.
    I SEE where the non technical minded might be more nervous
    than someone who built his own stereo for a class project once,
    but it didn't bother me a bit.:1:
  • 06-01-2011, 04:33 PM
    GMichael
    Quote:

    Originally Posted by pixelthis View Post
    Spoken like a true middle class person who only has to open a
    checkbook to buy anything.
    If you use a can of "fix flat" you can get that tire plugged for fifteen
    bucks or less. QUITE often the price of four new tires is out of reach,
    so its not even an issue.
    As much as I ENJOY THIS HOBBY, there is always something
    more pressing. In an age when gas for work is 160 a month,[I]plus[/I
    the gas to get around, with groceries costing a small fortune,
    if something is working I tend to not mess with it.
    THERE are targets of opportunity, like 29 bucks for a hundred dollar tuner, an EMO AMP FOR 250 BUCKS(haven't seen it that
    cheap again).
    RUNNING my sub on a receiver channel worked fine, didn't bother
    me at all, didn't hurt the sub, not the first time I have done it.
    And if I had not had a plate amp fall into my lap, I would be probably still be set up that way.
    BEING type two diabetic I need pills just to protect my kidneys.
    Pills and test strips, hundreds of dollars a month, visits to the
    doctor every three months. You can't get kidneys at RADIO
    SHACK.
    I DO HAVE a meager HT "budget" but you have to prioritize,
    and if something works you don't mess with it.
    I SEE where the non technical minded might be more nervous
    than someone who built his own stereo for a class project once,
    but it didn't bother me a bit.:1:

    Don't assume that my budget is any better than yours. The OP asked what was better, not what was cheapest.

    By the way, I am also type two. I also spent the last 6 weeks in and out of hospitals for my kidneys. None of which has anything to do with the fact that a receiver amp should be the very LAST option taken unless you have no options.

    As for non technical, I do have a degree in Science and worked 12 years in the T.J. Watson Research Center.
  • 06-02-2011, 10:46 AM
    Sir Terrence the Terrible
    Quote:

    Originally Posted by GMichael View Post
    Don't assume that my budget is any better than yours. The OP asked what was better, not what was cheapest.

    By the way, I am also type two. I also spent the last 6 weeks in and out of hospitals for my kidneys. None of which has anything to do with the fact that a receiver amp should be the very LAST option taken unless you have no options.

    As for non technical, I do have a degree in Science and worked 12 years in the T.J. Watson Research Center.

    I cannot believe he says you are non technical, but yet he makes this statement

    THE truth is that a sub is probably never going to need even
    the paltry 125watts put out by my receiver channel


    Is this person out of his mind? Yep. In a VERY small room, 125 watts MIGHT be enough. In a larger room, no way in hell is that enough. The lower you go in bass frequencies, the more power you need. The larger the room, the more power you need. When you combine these two facts together, you need a lot of power so you don't end up over driving the amp - or even pushing the driver into compression.

    In a small 12X15x10ft room I use a single H-PAS sub with a 300 watt amp. On several movies(The Haunted, War of the Worlds, and Saving Private Ryan comes to mind) the red lamp on the amp has lit up signaling that the amp is approaching its maximum power. This is with a 70db average dialog level which will produce 100db peaks at the maximum digital level of 0db. So you see, a 125 watt amp would be overloaded at that level easily.
  • 06-02-2011, 12:08 PM
    GMichael
    Quote:

    Originally Posted by Sir Terrence the Terrible View Post
    I cannot believe he says you are non technical, but yet he makes this statement

    THE truth is that a sub is probably never going to need even
    the paltry 125watts put out by my receiver channel


    Is this person out of his mind? Yep. In a VERY small room, 125 watts MIGHT be enough. In a larger room, no way in hell is that enough. The lower you go in bass frequencies, the more power you need. The larger the room, the more power you need. When you combine these two facts together, you need a lot of power so you don't end up over driving the amp - or even pushing the driver into compression.

    In a small 12X15x10ft room I use a single H-PAS sub with a 300 watt amp. On several movies(The Haunted, War of the Worlds, and Saving Private Ryan comes to mind) the red lamp on the amp has lit up signaling that the amp is approaching its maximum power. This is with a 70db average dialog level which will produce 100db peaks at the maximum digital level of 0db. So you see, a 125 watt amp would be overloaded at that level easily.

    I think he just says stuff like that to stir people up. I should have known better.
  • 06-02-2011, 12:35 PM
    JoeE SP9
    Quote:

    Originally Posted by GMichael View Post
    Next step is a BFD. For under $100 it's a huge addition to any sub.

    I just bought a Behringer DSP1124 for $99 from B&H Photo with free shipping. I ordered it Tuesday May 24 about 1PM. It arrived the next day via UPS.

    It's a 12 band per channel parametric equalizer with a built in 24/46 ADC/DAC (DSP). I chose this over the the DEQ2496 which has 20 parametric bands per channel a 24/96 ADC/DAC (DSP) and is ~$60 more expensive. For my purposes 12 bands per channel are more than enough for a device that will never see a signal higher than 100Hz. Currently the DSP1124 is connected to the low pass out of my crossover and from there to the bridged Crown's that drive my subs.

    Now that I have two 1U rack mount devices I pulled a Walnut Crown DC300 case I wasn't using out of the closet and bolted the DSP112 and my CX2310 (crossover) into it. They leave a 2U space open in the case. So, maybe I'll look around for a 2U amplifier for a center channel speaker that I've never gotten around to buying. The case is sitting on a black painted piece of spiked MDF between my front speakers. The amps for the speakers and subs are behind or next to their respective speakers.

    To use a BFD properly you need a calibrated measurement microphone and REW (Room Equalization Wizzard). REW is available for free at www.hometheatershack.com . You have to become a member (free) to get it. Behringer and Parts Express have calibration microphones available for less than $100. Both need a microphone preamp that provides phantom power for the condenser microphone element. If you have a Rat Shack SLM analog or digital it will also work. HT Shack has the correction factors for all the Rat Shack SLM's analog and digital.

    24/46 is not a slip of the finger. That's what it says in the manual.
  • 06-02-2011, 01:20 PM
    GMichael
    Quote:

    Originally Posted by JoeE SP9 View Post
    I just bought a Behringer DSP1124 for $99 from B&H Photo with free shipping. I ordered it Tuesday May 24 about 1PM. It arrived the next day via UPS.

    It's a 12 band per channel parametric equalizer with a built in 24/46 ADC/DAC (DSP). I chose this over the the DEQ2496 which has 20 parametric bands per channel a 24/96 ADC/DAC (DSP) and is ~$60 more expensive. For my purposes 12 bands per channel are more than enough for a device that will never see a signal higher than 100Hz. Currently the DSP1124 is connected to the low pass out of my crossover and from there to the bridged Crown's that drive my subs.

    Now that I have two 1U rack mount devices I pulled a Walnut Crown DC300 case I wasn't using out of the closet and bolted the DSP112 and my CX2310 (crossover) into it. They leave a 2U space open in the case. So, maybe I'll look around for a 2U amplifier for a center channel speaker that I've never gotten around to buying. The case is sitting on a black painted piece of spiked MDF between my front speakers. The amps for the speakers and subs are behind or next to their respective speakers.

    To use a BFD properly you need a calibrated measurement microphone and REW (Room Equalization Wizzard). REW is available for free at www.hometheatershack.com . You have to become a member (free) to get it. Behringer and Parts Express have calibration microphones available for less than $100. Both need a microphone preamp that provides phantom power for the condenser microphone element. If you have a Rat Shack SLM analog or digital it will also work. HT Shack has the correction factors for all the Rat Shack SLM's analog and digital.

    24/46 is not a slip of the finger. That's what it says in the manual.

    I'm only using 5 of the bands and probably could have gotten away with 3. I bought mine from a friend over at AH for $60. It was just sitting around not getting used at his house.
    It did a great job of taming a peek I had at 50.
    I have it connected to my LFE out and then on to an EP4000 amp (with the fan mod).
    It can be set up manually if you have the patients. I didnít have a laptop at the time, but wifey has one now. It may be time for some more tweeking.
  • 06-02-2011, 01:29 PM
    pixelthis
    1 Attachment(s)
    Quote:

    Originally Posted by GMichael View Post
    Don't assume that my budget is any better than yours. The OP asked what was better, not what was cheapest.

    By the way, I am also type two. I also spent the last 6 weeks in and out of hospitals for my kidneys. None of which has anything to do with the fact that a receiver amp should be the very LAST option taken unless you have no options.

    As for non technical, I do have a degree in Science and worked 12 years in the T.J. Watson Research Center.

    So you oughta know that it is no big deal.
    AND that is not the "last" option, a clock radio is.:1:
  • 06-02-2011, 01:37 PM
    GMichael
    Quote:

    Originally Posted by pixelthis View Post
    So you oughta know that it is no big deal.
    AND that is not the "last" option, a clock radio is.:1:

    I don't think that a clock radio will make a very good sub amp, but go for it.
    I have a baby monitor you could try if you like.
  • 06-03-2011, 12:36 PM
    pixelthis
    1 Attachment(s)
    Quote:

    Originally Posted by Sir Terrence the Terrible View Post
    I cannot believe he says you are non technical, but yet he makes this statement

    THE truth is that a sub is probably never going to need even
    the paltry 125watts put out by my receiver channel


    Is this person out of his mind? Yep. In a VERY small room, 125 watts MIGHT be enough. In a larger room, no way in hell is that enough. The lower you go in bass frequencies, the more power you need. The larger the room, the more power you need. When you combine these two facts together, you need a lot of power so you don't end up over driving the amp - or even pushing the driver into compression.

    In a small 12X15x10ft room I use a single H-PAS sub with a 300 watt amp. On several movies(The Haunted, War of the Worlds, and Saving Private Ryan comes to mind) the red lamp on the amp has lit up signaling that the amp is approaching its maximum power. This is with a 70db average dialog level which will produce 100db peaks at the maximum digital level of 0db. So you see, a 125 watt amp would be overloaded at that level easily.

    ACTUALLY the lower the freq the less power is required.
    THE REASON subs require so much power is some formula,
    forgot its name, but you need 17 times the normal power
    just to get the sound outta the box.
    SO YOU have the natural hardheadedness of the deaf.
    Explains a lot.
    WHEN I had the 600w BASH plate amp it was nice, excepting
    the few times the cops paid me a visit, but the current 130w
    plate amp works fine in my limited environment.
    My neighbors are certainly happier.:1:
  • 06-03-2011, 12:39 PM
    pixelthis
    Quote:

    Originally Posted by GMichael View Post
    I don't think that a clock radio will make a very good sub amp, but go for it.
    I have a baby monitor you could try if you like.


    It takes four or five in parallel for those to work, and sleeping
    with four single moms wasn't worth it.:1:
  • 06-03-2011, 12:44 PM
    GMichael
    Quote:

    Originally Posted by pixelthis View Post
    It takes four or five in parallel for those to work, and sleeping
    with four single moms wasn't worth it.:1:

    Sleeping? You were sleeping? That's not the way to do it.:nonod:
  • 06-03-2011, 01:41 PM
    Sir Terrence the Terrible
    Quote:

    Originally Posted by pixelthis View Post
    ACTUALLY the lower the freq the less power is required.
    THE REASON subs require so much power is some formula,
    forgot its name, but you need 17 times the normal power
    just to get the sound outta the box.

    Do you realize idiot you just contradicted yourself? The longer the acoustical wavelength, the more power it takes to get it in the room. They need more power because long wavelengths require a lot of power to push low frequencies through the air. That is why small bookshelf speakers can get away with 100 watts a channel, and most subwoofer require 200 watts at the minimum. And you know more than me? LOLOLOL

    Quote:

    SO YOU have the natural hardheadedness of the deaf.
    Explains a lot.
    WHEN I had the 600w BASH plate amp it was nice, excepting
    the few times the cops paid me a visit, but the current 130w
    plate amp works fine in my limited environment.
    My neighbors are certainly happier.:1:
    Here are some links that point out what an idiot you are.

    http://www.beoworld.org/article_view.asp?id=44

    http://15subwoofer.info/2010/subwoof...ers-explained/

    Note these words in the second link

    Subwoofers require more power than the main speakers because they have to push more air, which explains why subwoofers frequently have their own power source.

    So much for you less power statement. The more you say you know more than I do, the more stupid you look.
  • 06-03-2011, 10:37 PM
    Woochifer
    Quote:

    Originally Posted by JoeE SP9 View Post
    I just bought a Behringer DSP1124 for $99 from B&H Photo with free shipping. I ordered it Tuesday May 24 about 1PM. It arrived the next day via UPS.

    It's a 12 band per channel parametric equalizer with a built in 24/46 ADC/DAC (DSP). I chose this over the the DEQ2496 which has 20 parametric bands per channel a 24/96 ADC/DAC (DSP) and is ~$60 more expensive. For my purposes 12 bands per channel are more than enough for a device that will never see a signal higher than 100Hz. Currently the DSP1124 is connected to the low pass out of my crossover and from there to the bridged Crown's that drive my subs.

    Now that I have two 1U rack mount devices I pulled a Walnut Crown DC300 case I wasn't using out of the closet and bolted the DSP112 and my CX2310 (crossover) into it. They leave a 2U space open in the case. So, maybe I'll look around for a 2U amplifier for a center channel speaker that I've never gotten around to buying. The case is sitting on a black painted piece of spiked MDF between my front speakers. The amps for the speakers and subs are behind or next to their respective speakers.

    To use a BFD properly you need a calibrated measurement microphone and REW (Room Equalization Wizzard). REW is available for free at www.hometheatershack.com . You have to become a member (free) to get it. Behringer and Parts Express have calibration microphones available for less than $100. Both need a microphone preamp that provides phantom power for the condenser microphone element. If you have a Rat Shack SLM analog or digital it will also work. HT Shack has the correction factors for all the Rat Shack SLM's analog and digital.

    24/46 is not a slip of the finger. That's what it says in the manual.

    My BFD settings are based on manual measurement. The Home Theater Shack site still has the instructions posted on how to do the frequency measurements and set up the PEQ filters manually. They also had an Excel spreadsheet that graphs the before and after measurements, as well as the correction values for the Radio Shack analog SPL meter. If it's no longer on the Home Theater Shack site, let me know if you want me to e-mail it.

    I tried using the REW application with my analog meter, and it identified three filters that I should apply. I wound up getting some bizarre sounding results, so I reverted back to my original settings (I currently use 9 EQ filters). A calibrated mic might give some better results.
  • 06-04-2011, 08:27 AM
    GMichael
    Quote:

    Originally Posted by Woochifer View Post
    My BFD settings are based on manual measurement. The Home Theater Shack site still has the instructions posted on how to do the frequency measurements and set up the PEQ filters manually. They also had an Excel spreadsheet that graphs the before and after measurements, as well as the correction values for the Radio Shack analog SPL meter. If it's no longer on the Home Theater Shack site, let me know if you want me to e-mail it.

    I tried using the REW application with my analog meter, and it identified three filters that I should apply. I wound up getting some bizarre sounding results, so I reverted back to my original settings (I currently use 9 EQ filters). A calibrated mic might give some better results.

    9?!

    My my. Aren't you the master tweeker. How long did that take you to do manually?
  • 06-06-2011, 01:25 AM
    Florian
    I dont meant to ruin your wonderfull and structured conversation but i have a set of four subwoofers. And they are both passive and active.One of them has the amplifier attached to the subwoofer frame and the other set has the amp detached from the subwoofer frame. Both work wonderful and both sets are using the "sealed acoustic suspension" enclousure. One set uses 2 Krell Reference 200 amplifiers and the other set uses a older JVC MD 3030 stereo block. I use a Velodyne SMS -1 to flatten the inroom response and because one set if subwoofers uses a high efficency Focal driver Ót makes no difference if you use the smaller 55lbs JVC or the 253lbs Krell References.

    The most important topic was not even discussed in this thread, room acoustics and the integraton with the meain speakers. It does not matter if the amplifier is attached to the subwoofer or not....

    Cheers