What edge thickness should i be looking for when purchasing Sonotube and what's a good place to buy 14"+ diameter in Canada?
Most appear to be under 1/2" thick, is that enough for durability and keeping the sound in the tube?
It appears some people have had good success with the jl auto subs (mostly higher end) for ht in certian enclosures and i am curious what specs i should know about the woofer to calculate enclosure size through software.
Also is their a huge difference in sound quality and effeciency between the low end and high end Jl's or mostly just power handling?
I would like to hit as low as possible but having never heard much lower than 30hz anything deeper would be new to me.
I'm also stuck between building it shorter and wider with a plate amp on the top or picking up a used power amp and installing a low pass filter in the sub.
Either way i'd like to keep the cost down and i imagine 100 watts+ is a good amount of power for a small room, if the driver is somewhat effecient.
I would prefer a sealed build but i'm not sure how frequency response scales with size in sealed vs ported or wether sonotube is suitable for sealed?
If it could be kept to about 5-6' tall and around 20" wide or less without sacrificing sound quality than i would prefer to go relatively compact as well.
This sounds like an awesome way to jump into diy and I would greatly appreciate help with figuring out what software to use and how to go about putting this together and attaching the top and bottom wood panels to the tube.
This is the tube that got me interested in this build: http://www.avsforum.com/t/1460025/sonotube-build-pics
If it could be about half as tall and a few inches wider it would be perfect, although i'd like to put a basic finish on mine.
Thanks in advance
You can get the manual with all the T/s parameters from
This driver can only handle 125 watts so you're not going to get massive output from it. It seems to model best in a sealed enclosure that is 1.75 cu ft with 100 watts.
You can go ported but you would need a 7cu ft enclosure, tuned to 20hz, 75 watts with a 2nd order highpass at 20hz.
DIY Sound Group: Information and Tips
Also Fsc is the resonant frequency of the driver? if so it is quite high (though probably spot on for a car sub from what i've read).
People apparentlly put more along the lines of 200 to 250 watts into these based on the reviews i've read, they claimed rms but i'm not sure if there's a difference between car sub amps and ht amps?
Thanks again, and this is definetly more of a learning project than building a high spl super sub.
Edit: I read the manual and the 22hz resonance sounds a little more reasonable, but i'm still not sure how it fits the big picture?
The large box is required to keep the response linear and that is determined by the Thiele/Small parameters.
Fsc is the resonant frequency of the driver while in the enclosure.
There is no difference between car and home amps. They both amplify the signal and their output is measured in wattage. It is the intended use of the driver and the material being sent to it. For car audio, it is music and music contains very little low bass. Some old rock songs never get below 50hz. Home theater can dip in to the subsonic (under 20hz) range on a lot of action movies. RMS ratings on speakers are thermal ratings. That is how much power it can handle over a specific period of time before glue starts to melt and the sub just falls apart. That rarely happens in home audio. We have to look at mechanical limits. Let's say your sub moves 4mm when producing a 40hz tone at 90db (all hypothetical). To keep that 90db level and produce a 20hz tone, your sub would have to move 16mm. To keep the level the same and play an octave lower, your excursion quadruples.
You will either find this project tedious and give up or it will become a lifetime obsession. I built my first sub in 1987.
Definitely the second one
So basically i can grab the software, type in some parameters and mess around with the compromises, sounds like a plan.
The wattage to extension makes sense but only for a sealed build right?
What happens to the wattage numbers in a ported build?
The sealed 1.75' cu build doesn't look like it'll dip much below 30hz (although it has more output than i would have thought) not to mention the tube would be much less of a conversation piece at a couple feet tall
I'll mess around with the software for a bit and see if I can find a good balance between size and extension, my mains should be good to 40hz as well so sacrifices can be made to higher frequency linearity if that will help the lows.
I've heard of sonotube software as well which i'm guessing will be useful for figuring out the volume of the cylinder.
Other than that i'll probably run this off an old Peavey cs800 for awhile to see how it sounds rather than dropping the cash for a plate amp right away.
The Peavey has the classic pop on startup through the cv pa's though, is that likely to damage the sub?
Also a good soundcard with lfe out is a suitable low pass filter?
These simulations don't take into account the room's natural ability to boost the low end. It can't because it is room dependent. The sealed box doesn't look bad and in a small room will supply you with bass much lower than what that sim shows.
Here's the sonosub calculator - http://www.subwoofer-builder.com/sonosub.htm I used it when building three different ones. Two were passive cylinders with older, SVS Plus drivers (OEMed from TC Sounds) and one was an active cylinder with a Dayton DVC 12" and a 275w amp installed in the side like SVS does.
Depends on the voltage from the "pop" and how much mechanical clearance your driver has.
I've got a multimeter around so i'll make sure to test the pop voltage before making use of it.
Soundcard lfe outputs integrate low pass filters right? I've driven sub frequencies through full ranges from cheap onboard sound lfe without issues.
So far i like the looks of the sealed box at around 3 cu ft, The qtc drops as the box size goes up and i gain more in the lows than i sacrifice in the 60hz and up range but room gain effects the lower frequencies more right?
Does lower qtc=tighter bass?
And why does qtc dissapear under box settings for a vented enclosure?
Edit: Excursion limits surpassed for ported and larger sealed Back to the drawing board
If i'm dealing with ported should i know more about the available alignments?
Why does vent length decrease when i decrease the vent diameter, shouldn't they balance out instead?
So many questions
Once again thank you for all the help, i'll definetly be sticking around the diy forum in the future to help out newbies like myself after i've done a few builds.
We really don't use things like EBS or the other "named" alignments. What size box can you live with is usually our biggest question.
No. It's a Hemholz Resonator. The math backs up my statement - http://www.diysubwoofers.org/misc/portcal.htm
As I said earlier, I've been doing this as a hobby since the 1980's and it still brings a smile to my face when I crank up a new sub. I've taken it a step further and I have built my own drivers. Here's one example. No, that's not me in the video. I traded the sub to a friend that likes to post videos. it's a TC-7 motor from TC Sounds, a generic basket that no one can figure out the original manufacturer, a coil and spider from a TC-2000 (TC Sounds) and a cone/dust cap from Sundown Audio. http://youtu.be/kG38EfCnBI8
I'm mostly just stuck on finding a balance now. As long as this driver isn't known to be sluggish in a large ported box i'd probably only use sealed for preliminary testing at this point.
I believe my psb 500's will have better mid bass regardless of the scenario so i'm looking more at the 60hz and below segment making this a home theater sub rather than musical.
I've got it narrowed to around 5 cu ft with a port tune in the 22 hz region, hopefully i can get the graphs up'd tommorow.
Why don't you go a little smaller and tune higher? You only have 8.6mm of xmax to work with. Look at 3.5 cubic feet tuned to about 25hz. You will definitely need a subsonic filter no matter what ported enclosure you go with.
The article stated the speed of a woofer is actually due to the magnet structure rather than the woofer right?
I have an adjustable subsonic filter built in to my behringer ultragraph pro eq but i'm not sure the exact numbers it can be tuned to other than 25hz
Similar to this except without the feedback detection: http://www.musiciansbuy.com/mmMBCOM/Images/BEHRINGER_FBQ3102.jpg
It would be nice to know some examples of what effect diffferent sub frequencies at different sound levels generally have in a 150 sq' room.
I wonder how distorted it is, or whether it's even the driver they state it is, distortion cleans up at 45 seconds in.
Here's another but all that's stated is 12w0 not 12w0-4: https://www.youtube.com/watch?v=hzXV4dSiWYE
Seems like more than 0.3 inches, i might have to try this someday when it's time for an upgrade
Mik, it can't be said what kind of effects different freq's will have in a room. Each room is different. Things like furniture, drapes, carpeting, windows, material the floors and walls are made out of, the shape and volume of a room, etc all play a role in effecting sound waves and how they are absorbed or reflected. Also, every thing on this planet has what's called a resonant frequency. This is the natural frequency at which an object resonates, or vibrates, at. Look up the Tacoma Narrows Bridge for a good example. The bridge did this due to the wind traveling over, and under, it at just the right speed. In this case, think of blowing across the opening of a bottle. Except in our case, things will do this at very specific frequencies. I could make my cat vibrate apart if I played the right frequency loud enough. All of these variables effect the acoustics of the listening environment.
Back in the 90's when I worked for a local car audio chain, JL was just cutting their teeth in the industry. Nobody had really heard of them. I bought 4 12w1-8's and put them in the hatch of my Ford Escort in 1.25ft3 sealed enclosures and ran them bridged to 2 ohms with about 500w RMS. After those, only 1 sub I had ever came close to performing as well as the JL's did (Alpine ZR's). The W0 series is what replaced the original W1's. Back then, there were no W0's. Price was about $100 each and they handled 100 or 125w RMS each. If JL still makes subs like they used to back then, even the bottom of the line W0's won't let down. (As a side note, the W7's are what the W6's used to be, top of the line.)
What you get with the more expensive models, like the W7's (and most drivers really), is cast baskets (which won't flex under high power and stress) vs the W0's stamped baskets. Also higher Xmax, (how far a driver can travel in one direction before exceeding it's mechanical limits), larger voice coils to handle higher power, etc. In short, the ability to handle gobs more power. You don't want to run a sub rated for 500+w rms with only 100w rms. Bad things can happen and cause damage to the driver, amp or both. It's actually better to run a sub with more power than it's rated than less.
With a sealed enclosure, aka acoustic suspension, the enclosure is more forgiving when it comes to errors or compromises on internal volume. A ported enclosure, aka bass reflex, must be made to pretty close manufacturer recommendations. In sealed, the air in the box acts to damp and control the driver. Kind of like a spring on a cars suspension. It helps to keep the driver from exceeding xmax and tearing itself apart. In a ported box, you don't have that "air spring" because the box isn't sealed. This is where the term "unloading" that RLJ mentioned comes from. If the box size and port aren't carefully calculated and made, the air in the box no longer acts as a spring to help control the driver. At this point, Xmax becomes exceeded and the driver destroys itself. This is why the box and port size are critical.
On the subject of using a sonotube and the wall thickness. The thickness isn't as critical with a tube as it is with a regular box shaped enclosure. When we put a driver in a box type shape, there are 6 surfaces for the sound waves to reflect off of inside. Remember that bit above about resonant frequencies of an object? Well that comes into play here along with something called standing waves. The super thick (or thicker) 1 inch panels you see standard enclosures made from are that thick for a reason. To keep enclosure resonances down, which have a tendency to make things sound not so great. With a tube, we don't have all of those flat surfaces for the waves to reflect off of, thus not nearly as great a chance for the enclosure to resonate. The exceptions being the baffle where the driver is mounted, and the opposite end panel.
If I'm wrong in any of this in the slightest way, please, someone correct me. It's been a few years since I've built a sub and my knowledge may be a bit rusty.
Mik, what is the freq your mains play down to effectively without struggling? This point and lower is where I would focus. Me for example, my mains (Infinity IL40's) do a great job down to between 30-35Hz. I've been thinking about building a sub and focusing strictly on the 15/20-35Hz region. Some people are obsessed and insist on getting down to 10Hz or lower. This will cost some big $$$$ usually. If this becomes an obsession for you (as it does for most of us), it's inherent that you start reading and learning. Things only get more difficult, confusing, and expensive from here on out.
My mains are probably good to around 40hz before losing output and they start to plummet below 35.
Trust JL on their xmax numbers. Measuring them your way is a recipe for disaster because you don't know if xmax and xmech are the same. xmech is when the voice coil starts to hit the back plate or it jumps out of the gap. Neither one are a good thing especially hitting the back plate and you only having a Kapton former. JL either used the (winding length - top plate thickness)/2 method or the 70% BL method to determine xmax. Both are valid methods throughout the industry.
I have some 3" speakers that will play 40hz but they are down 40db from the other frequencies. Bass is about moving air and most of us like to use a crossover between 80hz and 60hz.
My 8" drivers will play 24hz at less than half the volume of 50hz but that's not usable response. I think 50hz +-10hz will be a good place to draw the line to avoid localization.
Thanks for the info cogeng, it's good to know the tradeoffs like group delay, which seems like a good reason for me to tune lower than what i want to use in a ported build, as long as it doesn't negatively effect higher frequency performance by more than a db or 2.
If you aren't familiar with XBL^2 - http://www.acousticdev.com/cms/index.php?option=com_content&view=section&layout=blog&id=12&Itemid=64
The inventor - http://www.acousticdev.com/cms/index.php?option=com_content&view=article&id=44&Itemid=55 Too bad Dan doesn't post much any more. Some of his posts here and at other forums were like attending a physics and acoustic lecture combined.
Basically i'm going with ported tuned so i know excursion will max out and be similar at around the 15hz and 30hz mark (depending on what i tune to). Then if I ever feel the need to test the limits i know if I test the 28-32hz range for distortion it will ideally reach the same maximum excursion at 15hz.
On the topic of hipass filters does anyone know what's in the behringer eq's? I selected butterworth hipass's for each potential build but i'm not sure if that is any thing like what the eq uses for "low cut".
Underhung speakers like the XBL^2 I linked to earlier have a thicker top plate like this Elemental Designs 13Av.2:
While overhung speakers are known for having a thinner top plate like this TC-9 motor:
Then there is the exception to the rule. Overhung subs with thick top plates. The best example is the TC Sounds 3 HP motor used in the current line of Axis subs but also the older TC-3000, Lightning Audio Storm series and some Eclipse models. The pictures in the link below are from the neodymium version but the measurements are still the same. While the TC-9 has a 1/2" top plate, the 3 HP has a 1 3/8" top plate. They also have long coils which gives them insane motor force and high excursion. I know. I use a pair of 15" TC-3000's in my home theater and I have 4 of those neo motors and parts to make them into 15" subs.
Looks to be a clone of the Audiosource amps, they also sell clones of the Audiosource subwoofers that got good reviews. Any step up from Pyle or Pyramid without breaking the bank would be nice.
With free shipping i could sell my cs800 and buy 2. One of the reviewers was running 1.8ohm subs off of them so i suppose i may be able to get away with 4ohms bridged as long as i don't max it out...?
Otherwise i could place a resistor in the tube to increase the load right?
The other option is the 70 watt partsexpress plate amp which would likely cost me 80$ or more to ship from solen.ca
I'll be building a sleek looking amp panel on top of the sub either way unless someone has a sleeker idea.
Something like this (excuse the bad doodling )
Resistors turn it into heat where? at the amp or the resistor?
I wonder if i could put an aftermarket fan in there somewhere, or put one above the vent...
Though i suppose i would have to power that fan somehow
And of course the amp vents at the top effectively ruling out the enclosure idea.
If i did wire the sub to the osd audio amp bridged would that just mean i would have to be careful not to push more power than it could with an 8 ohm load or would it heat up more at the same power output?