Subwoofer to pair with AV40's.

Good call on that Dayton. My friend has one (not sure if its the exact model) and it sounds very nice for a computer set up.

The extra diameter in the driver will help you feel the lowest of the lows compared to the two subs originally posted.

ummm klipsch sub8? Readily available and good
deals
to
be found.

yo..
what the hell..!??

the first sub only goes down to 37hz
the second sub goes down to 38hz

my three-way speakers can get lower than that..!

BEWARE:
all of these pre-made subwoofers (with and without amps) have a box tune that is at or around 30hz at best.

30hz is NOT low enough.. 20hz is better.. 10hz is pimping and 5hz is useable for movies.

i swear to god that the economy is pathetic.. 99% of the pre-built subs are gonna have a tune in the 30hz range.
you might as well use an EQ and take that 31hz slider and shove it all the way down and listen to your audio like that, because buying a pre-built subwoofer isnt going to help matters at all.

when the sub does try to play audio that low the box is going to lose all pressure and the sub is just going to flap back and forth and make a 'slapping' noise instead of producing something pleasurable.

i have a single 12inch woofer on each side of me.
i ported the box and tuned the thing to 28hz and then stuffed each box with polyfill.

unfortunately the tune of 28hz isnt low enough and i need to make new boxes with a tune of probably 20hz.
the trick is to tune the box as low as needed, because once the box loses air pressure the speaker cone is going to move back and forth at an exceptionally high force (which is perfect for trying to move lots of air at a very low soundwave)

think 5hz - good for movies.
and 10hz probably doesnt need a 3dB boost because the soundwave is so stretched out that the air-movement is desired rather than horn-amplifying a noise.

basically.. if you tune the box right, the box will lose air-pressure where you want/need it and the sub flapping without any pressure in the box is like having an equalizer with the far left sliders all the way up.

as the soundwaves get lower, the decibel level gets lower - but the sound pressure gets higher.
you need to find a nice blend that is smooth when going from one note to the next.
they say 20hz is audible to the human ear.. that means there is DECIBEL levels to be had, which means you need a box tune to help amplify that 'noise'
after that, there isnt any noise and all there is to be had is SOUND PRESSURE which is something you feel and not here.

it is a lot more fancy to make your own subwoofer.
you can go here:
Speaker Enclosure Volume Calculator
and use the box calculator.

basically you would want to input the ideal size of the box so it fits comfortable in your room.. then play with the port size/length to get a tune of 20hz.
its easy to use pvc pipe with an elbow joint for a port.
you can also use the cylinder box calculation to compensate for the port.
because if you add a port, you will make the internal cubic foot of the box smaller (which means you need to make the box wider or taller or deeper to compensate and keep the tune at 20hz)

i would suggest dual 6 inch subs (but good luck finding some at that size with any sound quality)

get yourself a bash plate amplifier
get some MDF from a local hardware shop (usually sold in giant sheets that will need a truck to haul it home for about 30-40 bucks)
then you need some kind of glue to smear on the edges were one wall meets another wall (you dont have to glue the walls together, but you should screw them together and seal the seams with silicone or something)
and then all you need is a table saw.
a table saw is NUMBER ONE and the most important thing.
dont try to make straight cuts with a circular saw or jigsaw.. these are not the right tool for the job and will only cause embarassment (no matter how steady you think your hand is)

and to top it all off you need to get some aero-port caps that are basically flares that go on the end of the port to keep the air from making noise as it enters/exits the port.
really makes it easy for the air to find the port and make its way out (one on each end)

a lot of the people in places like this have stock in products and they are trying to sell you something that will eventually result in more money in their pocket.

just dont screw around without a table saw.
you can use half inch plywood if you want.. just make sure you use a table saw.
and drill little tiny holes smaller than the screw before you drive the screw into the wood.

i could build you something for an example..
sub: Parts-Express.com:*Peerless 830452 10" XLS Subwoofer | Peerless 830452 10" subwoofer woofer XLS Nomex Cone speaker lf Driver bass shorting ring copper cap tymphany09
amp: Parts-Express.com:*Bash 300W Digital Subwoofer Amplifier | subwoofer amplifier subwoofer amp sub amplifier sub amp plate amp bash

set that amp up with a test tone and a multimeter so you dont put too many volts on the voice coil (which will make the coil get hot and melt the coating on the copper which will short the coil out)

with that much reserve.. you will have more dynamics for sound quality.
maybe you might interest yourself in a swapping of the caps in the bash amp for some superior quality capacitors made specifically for audio = even more details in the sound.

$300 + $50 for wood / screws / silicone

yeah its a bit much.. but that subwoofer is going to be worth much much more than you paid for it.
(think a retail price of at least $1,000)

i got some midranges from some tower speakers that cost $2,000 retail.
i only paid $30 for my midranges, and my entire project cost me about $280
but the sound is much much more than anything i could have bought pre-built for $280.

there is a huge craze to be had with building your own speaker boxes.
you can get the same performance for 1/10th the cost!!
and using a table-saw.. you really cant make a mistake unless you fall asleep making a cut.
and even then, if you fell asleep and pushed the wood into the guide.. there would be no errors to the shape of the cut.

i dont have a table-saw.. otherwise i would re-build my boxes and tune them lower.
its on my to-do list for when i have the extra money to rent a table-saw (or buy one) and can afford the cost of supplies.

if peerless made a six inch woofer i would recommend two of those (or even one of 'em with a high cutoff at 40hz and a low cutoff at 10hz)

you can make your jaw drop for little money if you purchase the speakers and make your own boxes.
there is a wave going around just like high-definition video.. except this is for audio.

5hz sounds like air moving.. sound, not the audible sound but the 'all was sound' silent night type.

5hz in a home theater is supposed to create a feeling as if the floor was moving up and down.

first of all.. the person said the room isnt big, so that will help a small cone produce well into the sub-bass area.
and then the person can put the sub by his/her legs to help pass notes that are ment to be felt rather than heard.

there are two ways to do this.
one would be trying to move all the air in the room at a low frequency.
the other way would be moving the air by the legs to 'inform' the listener of subsonic frequencies by moving pant legs or hair on the legs.

the consumer market wouldnt know why they would need a box tuned that low because they havent been before a demonstration to display why such a thing is needed.

listen to a sine wave creator at 30hz and then again at 28hz and again at 25hz and again at 20hz
if you are lucky enough to have speakers that can produce any output at these notes, you will see that BASS goes lower than the average 30hz that is offered by 99% of pre-built subwoofers.

5hz doesn't sound like air moving, it IS air moving. 5 cycles per second, to reproduce sound that low (assuming your source even contains it, most movies don't have very much in terms of infrasonics to begin with) requires a massive amount of power to reach levels that our bodies can feel. Our ears are seriously insensitive to sound below 20hz, so in effect you have to have enough power and cone area to move enough air so that our bodies can feel it.

I'm a fan of DIY speakers and I'm all for serious subwoofers for home theater and to a lesser degree music; but I simply can't agree with what you're recommending. The OP is asking for a small subwoofer to add to his small bookshelf system that consists of two 4" woofers powered by 20watt/channel amps and you start recommending a subwoofer that can reach 20, 10, 5 hz? Try to keep some sense of scale Also, not everyone has the tools for, nor wants to DIY.

The Dayton 10" should be a good pairing, though for the size of the AV40's I'd personally would look for an 8".

i have two 12's with 100watts / channel and i can throw 5hz
i cant feel it but if i had two more identical towers i probably could start the sensation.

the first mistake was buying some 2-way speakers with a desire to hear some bass.

20 watts/ channel isnt much.. and it wouldnt take much to drown those speakers out with the subwoofer i mentioned, but you are supposed to be using the sub linear with the midranges and tweeters anyways.
peerless makes some dynamic speakers.. so running the sub from 10 or 20hz up to 80hz shouldnt cause much of a sweat, especially since there is 'xtra long stroke' to get all that needs to be said out into the open.

the original poster doesnt comprehend much, as proven by the statement that was made 'For one I don't think an 8" is going to produce anything near that low.'

peerless has some mini subs for sale at madisound and might match the wimpy 20 watts/channel better.

those little subs would have a hell of a time getting down passed 30hz on the same decibel level as the av40's

regardless of what gets chosen.. dont fall for something with a high low-end frequency response.
some are 30hz some are 40hz
some say 25hz and really stop at 32hz

Just going thru the list, there were a few things I just couldn't let be.

Do you put your three-way speakers on your desk? Keep in mind the context, the OP has AV40's.

Infrasonics are overrated. Way too much power and resources required to reach levels where you feel it while very little source material contains it. I actually put a sub-sonic filter in my home theater setup to to improve the power response of my HT sub.

Unless I'm reading this wrong, what you're referring to is over-excursion which isn't a good thing.


Sound pressure is measured in decibels, so I'm not sure how you're saying the decibels are lowered but sound pressure is increasing. If the decibel level lowers, then so does the sound pressure.

Wait, all that talk of 20/10/5hz and you recommend a 10" woofer with a 300watt amp? Granted, we don't know what size the OP's room is, but still I find it funny.

There's much more to retail pricing that simply parts cost, it's naive to compare a DIY project parts cost to a retail produced products pricing.

If someone fell asleep while using a table saw, I'd expect at least a finger or two lost at a minimum.

How are you commenting on the safety of a table saw if you don't have one? I'm assuming you haven't used one either, by the way you speak of it. You can NEVER overstate the need for safety around tools such as the table saw. The second you stop respecting it, you will lose a finger or more.


You say you can throw 5hz, so I challenge you to play a 5hz test tone, then post just how many decibels you're actually hearing. With two 12's at 100watts each, I'm going to guess....not much.

On the contrary, he's right. I would say you need a lesson on physics and possibly speaker building. A 8" woofer will NOT produce much meaningful output at 5hz and if you tried, you would blow it up.

picking apart my post and offering nothing constructive is really a tedious hobby for some.
i understand that.
i didnt realize when i first wrote the post that the av40s were wimpy 4 inch woofers with 20 watts per channel.

i must admit, my suggested project doesnt quite fit with what the OP already has.
but speaking as though decibel levels and sound pressure levels are the same thing is naive and promptly shows a lack of training/education/understanding.

i'll set you straight here..
if i pump 10hz into a room so strongly that it takes the air out of your chest (in/out) without your allowance, there is nothing to be heard with your ears.. but the pressure from the speakers is what is forcing the air to leave/enter your lungs.

your little comment 'infrasonics are over rated' is an opinion and implies to me that you either dont hear much subsonics in todays music, or you simply dont respect it.

and to sum things up..
there is no 'over-excursion' as long as your voice coil isnt rubbing on the magnet or pole piece (and the cone cant stop/pause/halt during travel).
allowing the sub to move in 'free-air' type because the tuned box has lost all pressure is allowing the cone to move with more excursion which means more output.
there is no reason why you shouldnt be at linear excursion limits @ 5hz unless you have plenty of punch prior to reaching that point.

four twelves and 400 watts in a very small room is a great way to start feeling the air waves @ 10hz.
(something smaller than 20ft x 20ft)
them four towers and a sub in a box that wont start to flap around below 30hz will certainly pump some vibes into your torso.

I agree with Nebby the Dayton is probably a good match up for what you have. You cannot hear anything below 20Hz and when you get down to even 20hz or below you need a very large driver and alot of power.
Most of it is vibration that you feel but not hear.