subwoofer... passive or powered?

[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.

[pixelthis]

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.

[markw]

You're gonna have to figure on a low-pass filter (at least) somewhere in the mix.

[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.

[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.

[Sir Terrence the Terrible]

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.

[bfalls]

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.

[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.

[pixelthis]

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.

[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.

[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.

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?

[pixelthis]

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.

[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.

[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.

[pixelthis]

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.

[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.

[GMichael]

Next step is a BFD. For under $100 it's a huge addition to any sub.

[JoeE SP9]

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.

[GMichael]

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 didn’t have a laptop at the time, but wifey has one now. It may be time for some more tweeking.

[Woochifer]

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.

[GMichael]

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?

[dingus]

whats a BFD?

[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/

[dingus]

ah yes, thank you!

[N. Abstentia]

Yeah I didn't say it couldn't be done...I just said it couldn't be done right!