A Guide to Subwoofers (Part I): Characteristics, Placement, & Adjustments

[Silo5]

thanks, BD.

[bikerman]

Originally Posted by Big Daddy

Set it slightly higher than the crossover frequency you pick in the receiver.

Where do I set the sub volume? Do I turn it all the way up on the sub and control it with the receiver?

[Big Daddy]

Originally Posted by bikerman

Where do I set the sub volume? Do I turn it all the way up on the sub and control it with the receiver?

Don't set the volume all the way up as you may introduce distortion. Set it around the mid+ level and control it with the receiver. After calibration, if you realize that your sub is still too high (or too low) and you cannot control it through the receiver, turn it down (or up) a little and calibrate it again. Experiment several times until you get it right. Make sure neither your receiver's control nor your subwoofer's control is at the extreme (max or min) point. Give them some room.

[krazeyeyez]

can i put my subwoofer near my lcd tv? i have heard that the magnet won't damage an lcd tv, is this true? and what about the bass itself, is it ok to have it near the tv or can the bass itself cause damage, because i know not to have disc players near it.

i ask because if their is no risk involved i would like to have my sub between the left and right and just off to the side of the television stand.

[Big Daddy]

Originally Posted by krazeyeyez

can i put my subwoofer near my lcd tv? i have heard that the magnet won't damage an lcd tv, is this true? and what about the bass itself, is it ok to have it near the tv or can the bass itself cause damage, because i know not to have disc players near it.

i ask because if their is no risk involved i would like to have my sub between the left and right and just off to the side of the television stand.

Magnetic interference doesn’t affect LCD TVs. It is a problem for CRT (tube) monitors. As far as vibrations are concerned, make sure the subwoofer is stable enough so that it does not rattle. If it is on a hardwood floor, put an area rug under it or make it stable enough so that it does not move. It is still possible (not likely) for loud bass sound to make your DVD/CD player or your record (LP) player to skip. Make sure the players are on a flat and stable surface. Don’t worry too much. Subwoofers will not damage your equipment. However, they can damage your hearing or your relationship with the neighbors. The only solution is to turn the volume down a little.

[jomari]

very informative posting big daddy! im sure it took a lot of time for you to create such an informative yet 'simply in engresh' reading material for the beginners.

@silo5,

read the specs of your soundstage, determine at what frequency you want to setup your receivers crossover at, and set the subwoofers crossover slightly above the determined setting.

ie
front stage - rated around 55hz,
receiver crossover - 60hz (if possible)
subwoofer - can range from 60-80hz, depending on your spl meter reading.

without a spl meter? well, thats just setting it up blindly friend. do yourself a favor and purchase one to get a good read, and you can see the improvement.

if you'd rather want to do it by ear, then see how 'good' it sounds to you.

[mugen302005]

Sorry If I posted this in the wrong place.

I have a denon 1908 receiver and 2 n38 jbl front speakers, and a philips subwoofer FB301 . The thing is before i changed to this receiver I had a sort of high gama receiver kenwood x9060d and when i tried pcm 5.1 and all the Hd audio optios of bluray I was awed. Not that I had to change to the denon i noticed the "boom" of the first set is missing .

I tried figuring out setting the denon and came across this setting. No subwoofer, front speakers at 80hz, center alt 60hz and surrounds at 60hz too. And the crossover option is at 250hz. With this setting I kind of got the sound i was used to, but something makes me wonder why in my previous receiver all was in boom and ok, and now i had to stop using my subwoofer.

I have to add that i myself set the front speakers to 80hz because after the auto set up with the microfone, the values given for the front speakers was 40hz but as i rise this value the boom seemed to return.

Can you tell me if this is ok if my rising the crossover value for my frontt speakers is ok or not? and if the subwoofer gone is the way to go?

Thanks in advance.

[colofan]

One word of caution about using any type of shielding (less of an issue with most displays now). Puttin on any aftermarket shielding does affect the magentic field which affects the performance of the driver and not in a good way. There are many reference articles on speaker design around how the magnetic field is affected. Change the force lines on a motor (speaker) you affect linearity in a real sense.

One last comment about xmax isn't everything. Well in true sub fashion below 30 Hz which is where the sub should pickup from the main speakers xmax is the specification that rules.

Also a couple of articles on the www.aes.org web site on where to crossover a sub with the mains and usually it is below 80Hz so directivity is not an issue.

Mechanical shakers work best below 20Hz as well to agument the "bass" experience.

[Big Daddy]

I have seen this question asked several times on this forum. If you have an unpowered (passive) subwoofer and you need an amplifier to drive it, here are some inexpensive choices. Passive subwoofers do not normally have an RCA input (no LFE) and have standard speaker input terminals.

Standard Stereo and Monoblock Amplifiers:
http://www.partsexpress.com/webpage....up_ID=756&SO=2

Most stereo amplifiers can be bridged to act as mono amplifiers to drive a single speaker.

Subwoofer Plate Amplifiers:
http://www.partsexpress.com/webpage....ctGroup_ID=505

Rack Mount Subwoofer Amplifier:
http://www.partsexpress.com/pe/pshow...TOKEN=51614285

[pab1219]

thanks bd i am in the market for a new sub, and being a newbie to understanding tech talk this mosssssssssst needed. i have a yamaha3800avr, paradigm montior9 frints montior7 surround c370 center and i can.t of what my sr backs are but they are parsdigms. everyone speaks highly of the mfw-15, looking at that your thoughts?

[Big Daddy]

Originally Posted by pab1219

thanks bd i am in the market for a new sub, and being a newbie to understanding tech talk this mosssssssssst needed. i have a yamaha3800avr, paradigm montior9 frints montior7 surround c370 center and i can.t of what my sr backs are but they are parsdigms. everyone speaks highly of the mfw-15, looking at that your thoughts?

The MFW-15 is considered to be excellent. There is a thread on Audioholics on it. Also, you can look at the List of Subwoofer Manufacturers. There are reviews in the bottom.

[Go Blue]

I have notice that in my seating position, I can't "feel" the bass. I can hear the picture frames rattling on all the walls in the house. Can an "expert" take a look at my set up under my avatar and let me know what you think? As you can see it is in a nook and there is really nowhere else to place it.

[JJ]

Few qs, Schultzy - what sub is it? What's the distance from it to you, and I'm assuming you've run whatever auto-calibration process your receiver has?

What's the size of your little HT space, anyway? ...whole room (area?), not the nook.

[Go Blue]

Originally Posted by JJxiv1215

Few qs, Schultzy - what sub is it? What's the distance from it to you, and I'm assuming you've run whatever auto-calibration process your receiver has?

What's the size of your little HT space, anyway? ...whole room (area?), not the nook.

Its a Velodyne DPS-10. I'd say it is 12-15 ft away from my seating position. I have run the Onkyo 605's Audessey auto-calibration with mic. It is a fairly large room as it is half kitchen half living room. Maybe 400-500sqft?

[Big Daddy]

Originally Posted by schultz

I have notice that in my seating position, I can't "feel" the bass. I can hear the picture frames rattling on all the walls in the house. Can an "expert" take a look at my set up under my avatar and let me know what you think? As you can see it is in a nook and there is really nowhere else to place it.

If you only move the subwoofer a few inches or a couple of feet, you will be surprised how the level of bass sound changes. This is due to a phenomenon called Standing Waves. I suggest that you use the subwoofer crawl technique. It helps if you buy/borrow an SPL meter. Read A Guide to Subwoofers (Part II): Standing Waves & Room Modes. The subwoofer crawl technique is explained there. There is a short clip from Axiom Audio.

[Brain Sturgeon]

While doing some reading about the various commercial subs available out there, I came across these well received compilations of testing/reviews of subs. Just thought I'd share them:

http://home.comcast.net/~frank_carter/Nousaine.htm
http://www.hometheatershack.com/foru...rer-model.html
http://www.tweakcityaudio.com/forum/showthread.php?t=11

These are, of course, all property of Tom Nousaine, Ilkka, and Craigsub; and I did not get their permission to list these so I hope it's okay.

Some others listed elsewhere in this sub section (I corrected some of the dead links) by Big Daddy include:

http://www.avtalk.co.uk/forum/index....t=0&rid=0&SQ=0
http://www.hometheatermag.com/subwoofers/
http://reviews.cnet.com/4566-11312_7-0.html?tag=pm
http://hometheater.about.com/od/loud...er_Reviews.htm
http://www.audioholics.com/reviews/speakers/subwoofers
http://www.hometheaterhifi.com/compo...ag,Subwoofers/
http://www.audiovideoreview.com.au/S...subwoofers.htm
http://www.ultimateavmag.com/subwoofers/

[Big Daddy]

Hi Brain Sturgeon,

Thanks for doing this. However, in A Guide to Subwoofers thread, some of these links are listed there at the end. If you don't mind, I will add the links that are not in that thread to the list. The other alternative is to merge this thread into that.

[Brain Sturgeon]

Yup, that's fine. I actually took those links from that thread and fixed a couple of the dead ones. Either rolling these links into that thread or stickifying a new "review link" thread would be fine... whichever you think would work best.

Cheers mate!

[Big Daddy]

Originally Posted by Brain Sturgeon

Yup, that's fine. I actually took those links from that thread and fixed a couple of the dead ones. Either rolling these links into that thread or stickifying a new "review link" thread would be fine... whichever you think would work best.

Cheers mate!

I added all the updated links to the OP and merged the two threads. You don't have to worry about ownership rights of those links. That CraigSub link has been posted multiple times in the Elemental Designs thread to push ED subs.

[Brain Sturgeon]