Unpowered subwoofers are better than powered ones.

[Sheep]

What you are saying does not make any sense. If a subwoofer is capable of moving everything in the room, surely it is capable of moving itself.

Erm, so you're saying a driver should completely break loose from it's enlocure simply because it's moving? The subwoofer needs to be built strong enough to RESIST these vibrations. Decent subs do. Yes, there is some crappy subs out there that vibrate, but you can't label every powered sub as such. Passive subs included.

I get the distinct impression that you have not tried what I suggested. I can feel the vibrations from EVERY subwoofer that I have placed my hand on, when it is producing deep bass. I guess you imagine that I need to upgrade my SVS CS-Ultras to something better....

I think you don't know enough on the topic at hand which has given you a misguided opinion. Do you think every road paved in the work is as smooth as a race track? Heck no. Guess what? When I take my car over a speed bump, it doesn't explode. Products with any quality are made to handle these kinds of things. BASH indigo, the company that makes SVS' plate amps, build high quality Class D amps that can handle what the subs put out. A couple vibrations are not going to destroy everything in their path, nor will they be audible to the human ear.

Oh, and to poster "sst".... you suck.

SheepStar

 

[Pyrrho]

Erm, so you're saying a driver should completely break loose from it's enlocure simply because it's moving?

No, that isn't what I mean at all. I mean, if a subwoofer can vibrate everything in the room, it surely can vibrate itself. No matter how solid the subwoofer cabinet is, if it is vibrating the entire room, it necessarily will be vibrating itself.

The subwoofer needs to be built strong enough to RESIST these vibrations. Decent subs do. Yes, there is some crappy subs out there that vibrate, but you can't label every powered sub as such. Passive subs included.



I think you don't know enough on the topic at hand which has given you a misguided opinion. Do you think every road paved in the work is as smooth as a race track? Heck no. Guess what? When I take my car over a speed bump, it doesn't explode. Products with any quality are made to handle these kinds of things. BASH indigo, the company that makes SVS' plate amps, build high quality Class D amps that can handle what the subs put out. A couple vibrations are not going to destroy everything in their path, nor will they be audible to the human ear.

Oh, and to poster "sst".... you suck.

SheepStar

You obviously have not been paying attention to what I have been saying, as I never said anything as ridiculous as you seem to imagine (as with your comment: "vibrations are not going to destroy everything in their path"). You might want to actually read what I say before responding.

Surely, you do not imagine that extra vibrations are good for amplifiers, do you? Imagine that we take a bunch of amplifiers, all of exactly the same high quality vibration-resistant design, and we subject half of them to vibrations, and the other half we keep still. If all else is equal, which would you expect to last longer?

 

[Sheep]

You obviously have not been paying attention to what I have been saying, as I never said anything as ridiculous as you seem to imagine (as with your comment: "vibrations are not going to destroy everything in their path"). You might want to actually read what I say before responding.

Surely, you do not imagine that extra vibrations are good for amplifiers, do you? Imagine that we take a bunch of amplifiers, all of exactly the same high quality vibration-resistant design, and we subject half of them to vibrations, and the other half we keep still. If all else is equal, which would you expect to last longer?

Do you think bumpy roads are good for a car? No, but as I stated before, cars don't blow up when faced with a challenge. If the amp can handle the vibrations, then whats the point in doing everything possible to make them no longer affect it. You should call SVS and ask them how many amps have failed due to vibration. If you built a sturdy subwoofer, less vibrations would be stransfered to the internal components. Oh, call BASH as well. They make the amps.

Ok, lets say you're right, and the amp vibrates in the subwoofer, and the subwoofer vibrates everything in the room. Where is the external amp? In the room!?! But it will vibrate! Well I guess by your logic you would need to relocate the amp outside of the listening room. I don't know about you and your handy skills, but I think placing a sub in a room and plugging in power and line level cables is easier then that.

SheepStar

 

[dobyblue]

My house's foundation receives just as much vibration from my Paradigm Servo 15v2 as the amp in the sub, the receiver for my HT, my telly, etc., does.

I would never go back to passive subs.

 

[MACCA350]

One thing that is not mentioned is quality of amplification. An external amp e.g. a powerful receiver or Class AB amp provides "higher quality/distortion free" power with fast delivery as needed. So if you are listening to music , a subwoofer powered by class AB amp will sound better than a powered subwoofer with a class D amp ( Class D amp provides low quality power or higher distortion at a slower delivery rate)

Maybe you should tell Velodyne they don't know how to build subs

cheers

 

[Warpdrv]

I would never go back to passive subs.

Unless of coarse your building your own, "The ONE to rule them ALL"

If I could put an amp on board the subs Im building, I would, but Im not sure they make bash amps that big..... So passive it will be...

 

[eljr]

so if you are considering a separate amp for your sub, how would you gage your power need?
Would you need a power amp rated at about the same as you right and left channel amps? More, less?

 

[Johnd]

so if you are considering a separate amp for your sub, how would you gage your power need?
Would you need a power amp rated at about the same as you right and left channel amps? More, less?

Your question makes no sense to me eljr.

If you're talking of the needs of a passive amp, they are usually rather power hungry...it depends on the sub (regardless of the right and left channel amps).

 

[Dolby CP-200]

My JBL is powered at the moment by single channel Alesis RA300 which will soon be powered by a Alesis RA500 and a DCX2496 loudspeaker management system for greater control. The sub or LFE.1 is only used by the JBL 4645 it can shudder the room to the point of window rattling at 126dbc, if I was so inclined to do so.

 

[eljr]

Your question makes no sense to me eljr.

If you're talking of the needs of a passive amp, they are usually rather power hungry...it depends on the sub (regardless of the right and left channel amps).

i understand that it is based on the need of the Speaker.
Let me be very exact as I am not being very clear with my question.
I have 500 watt mono blocks driving my two channel system. The speakers are B&W 803d's. What would you/anyone suggest for a passive sub and amp to drive the sub or what self powered sub do you feel would be compatible?
Thanks in advance
eljr

 

[Adam]

Okay, I'll join in on this one now. I'll just hit a couple of the things.

First of all, you don't have the amplifier being so vibrated as one that is built into the cabinet, so the amplifier is less likely to fail.

That depends on a few things:
1. The susceptibility of the amps to vibrational failure. Some amps are designed to withstand higher levels of vibration than others.
2. The vibration levels at the amp locations. It is possible to have higher vibrational levels at locations away from the sub, as well as at the surfaces of the sub that you can feel compared to the location of the internal electronics.

Fourth, many people experience difficulties with "automatic on" subwoofers. Those stupid auto signal sensing things are not a good idea, as it must turn on only AFTER the music starts. And then they shut off if the music is quiet for an extended period (or with a subwoofer only signal, if there is no deep bass for a while).

The solution to the problem is to buy unpowered subwoofers, use a separate power amp, and an automatic switched outlet strip, such as:

http://www.smarthomeusa.com/Shop/Sma...pecifications/

where one plugs in one's receiver or preamp into the "control outlet", and the subwoofer power amp into one of the automatically switching outlets. It works great. I know, I am using one of these strips with the power amp for my SVS CS-Ultra subwoofers.

With the setup I suggest, it turns on as soon as the receiver or preamp turns on, and turns off only when the receiver or preamp is shut off. So it does exactly what it should do, unlike those stupid signal sensing automatic on circuits.

I totally agree that the auto-on functionality of a lot of powered subs could be improved. HOWEVER, unless I'm just way too tired to think, you could do exactly the same thing as what you've described above with every sub that I've seen with a built-in amp. The amps that I've seen have three power selections - off, on, auto. Set it to "on," plug it into the power strip just like your external amp, and it will do the same thing.

I mention these things because I don't want people to get the impression that those points are universally true functional reasons to buy passive subs and external amps. In the end, I see this as just personal preference. I personally like subs with built-in amps because I like the convenience of the all-in-one package. I specifically didn't buy an NHT sub tens years ago because their amp was an external box. That's just me, though. Cheers.

Adam

 

[Warpdrv]

i understand that it is based on the need of the Speaker.
Let me be very exact as I am not being very clear with my question.
I have 500 watt mono blocks driving my two channel system. The speakers are B&W 803d's. What would you/anyone suggest for a passive sub and amp to drive the sub or what self powered sub do you feel would be compatible?
Thanks in advance
eljr

Did you have a specific sub in mind.... It really depends on the what the application is...

For instance, I am building my own sub, and the driver is capable of handling 800 watts continous, 2500 watts peak power and then it starts to get into the enclosure you have, if its ported it will need less power as the driver is free to move back and forth, if its sealed you'll need alot more power to overcome the resistance of the sealed box... I will be buying an amp that is rated around 2000 wpc, to utilize the high powered transient spikes that are found in many movies...



Im going to do passive, which is pretty much like ported, but I will

 

[Warpdrv]

argghh got called away...

Anyways.... with 2 seperate boxes each with a 15" TC-2000 I'll be looking for a tall order of output in my very large room... I doubt I will be utilizing all the wattage I will have in reserve, but I know its there to handle all the needs these drivers can require...



Are you looking for a new sub for your system...? There are plenty of great powered subs out there, and are great products without having to go passive and getting a seperate amp here...
Do you have a budget? What receiver are you running....

I would look at any ID brands and get a powered sub.... alot easier to setup then a seperate amp and passive sub...

 

[eljr]

Here is what I had in mind but I would rather have a passive sub and an power amp to drive it.



http://www.hometheaterstore.com/Pro...ductCode=ASW855

http://www.hometheaterstore.com/Pro...ductCode=ASW825

http://www.harveyonline.com/product...a.model,a.title

http://www.stereoexchange.com/catal...ubcategoryid=74

 

[Sheep]

Unless of coarse your building your own, "The ONE to rule them ALL"

If I could put an amp on board the subs Im building, I would, but Im not sure they make bash amps that big..... So passive it will be...

There is 1000watt plate amps at Parts Express (BASH). What the heck kind of sub are you building?

SheepStar

 

[bandit]

I personally hope that my plate amp gets completely blown to bits by all the massive vibrations that I am told it has to withstand in this thread.... although this hasn't happened yet and I won't hold my breath... But if it does I can go shopping for one of those new SVS Ultra's... or some other awesome sub. Seems to me that half the fun in all of this exploring the ideas of new/different/better equipment.

I also believe that the individual that started this thread really doesn't want to hear other individuals opinions... except for sake of argument and debate.

Bandit.

 

[Johnd]

I also believe that the individual that started this thread really doesn't want to hear other individuals opinions... except for sake of argument and debate.

Bandit.

Right on point Bandit. Peacemaker you are. But with a header like "Unpowered subwoofers are better than powered ones" do you really not expect a few egos to get bruised? I personally feel that I've exercised great restraint in foregoing my personal commentary. Servo v2. Hmmmmmmm.

 

[Warpdrv]

There is 1000watt plate amps at Parts Express (BASH). What the heck kind of sub are you building?

SheepStar

http://forums.audioholics.com/forums/showthread.php?t=33649

1000watt, not going to cut the mustard....
Ive been doing my homework...

Its been going through....a number of iterations, have narrowed it down to a one 15" driver, and dual 18" passives for each box....

 

[Sheep]

What exactly is missing from your current situation? Your sub is tunable to 16Hz...

I mean, it can't be louder then your speakers, so getting a sub that is louder is stupid. A sub that goes lower will make literally 0 difference unless you like WOTW and Sine waves, and one that is bigger... stupid.

Seriously, what is your logic behind this upgrade? Want it flatter? Buy an SMS-1. Hell of a lot cheaper, and hell of a lot easier.

SheepStar

 

[Warpdrv]

If you were talking to me Sheep.... My intentions and goals are for cleaner, deep effortless bass... I like my currents subs, but I thought I would try my hand at DIY....

My room is already ruler flat, and I have a SMS-1...... There is no logic to what Im doing... Its just stupid impulsive stuff... but the main reason is because I can... I do recall many times reading this disease we have here has also been called a hobby... and it puts a smile on my face when I see someone in my theater c@p their pants when the bass hits low and hard...

If I didn't have such a large room, the subs I have would probably be enough... but they aren't....