My DIY sonotube sub is done. Pic and impressions inside.

[JonW]

It’s done and, right away, I’ll say I’m very happy with it. This was my first DIY project. Before starting, I wasn’t even sure what a router is. I borrowed one for the project. But I had so much fun making the sub that I’ve since bought my own tools and will soon be trying to build some speakers.

Huge thanks go to Steve Callas. My sub is, basically, a copy of his. He did all the design work and I just made what he made. It’s over-engineered and I like that. Steve was incredibly helpful, beyond what anyone could hope for. He provided me with very detailed plans to build the sub and then was kind enough to answer pages and pages of my newbie questions. And he’s a really nice guy. Thanks, man.

Details on the sub: It’s built around an Ascendant Audio Avalanche 18” driver. I was fortunate enough to get one of the last ones. The sonotube is 28” diameter (not easy for me to find). The port is made from 8” sonotube. For the end caps, inside, they are made of MDF. The outside, visible parts are from pine, including the base plate. Tuned to 14.5 Hz. The base plate is 36” diameter. Overall, it’s about 7 feet tall.

For expense breakdown, it worked out to something along the lines of: $300 for the Avalanche 18, $175 for the sonotube delivered, $565 for a used Crown K1 amp, $140 for the pine, $40 for the MDF, $60 for the cloth and having it sewn into a tube covering, about $200 for things I screwed up or broke and had to repurchase, because I don’t know what I’m doing (d’oh), and about another $300 for miscellaneous things like cable, binding posts, T-nuts, glue, caulk, dowels, some wood, stain, urethane finish, screws, etc. For a total around $1650.

As you can see from the photo below, it’s a monster. Two friends, independently, had the same impression when they saw it: It looks like an ancient, Easter Island-esque homage to the gods of bass. No, I don’t keep it in the middle of the room like that. The photo is from when I put it all together, at last.

It sounds pretty good. Although I must admit that I’m not properly calibrated to what a good sub should sound like- this is my very first one. I figured I might as well do it right, once, and never want an upgrade (IB couldn’t work in my house). I’m much more of a music guy than movies. The sub adds that extra punch at the bottom end. As far as I can tell, it’s really clean, not boomy at all. It seems like maybe only a 5-10% addition to the spectrum of music put out by my main speakers (Totem Forests), but it makes music much, much nicer. However, I fully admit it’s overkill for music. The sub is hardly even working. I probably could get away with a significantly smaller sub. For movies, it’s quite impressive. My 100 year old house, with wood floors, really shakes a lot. To the point that I’m worried about the house. Steve listened to a movie clip and thought the floor might be flexing. I didn’t notice such a nuance, as I was just too concerned about house damage. I guess that mean’s I’ve got enough output. Some explosions, cannon shots, etc. really sound like cannon shots, near as I can tell. Really clear and not boomy at all.

That’s the story. I’m happy to answer any questions if there are any. Thanks to all for the tips, ideas, and inspiration I picked up along the way. It’s been very fun. Now on to making speakers.

-Jon

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[TacoD]

Wow, over 500 years they will find this relic and want to know if it was used as a weapon of mass destruction .

Great project and very nice result. (how big is that room??)

[Ilkka]

Wow, that picture really shows how f*cking big that thing is! The pictures Steve has from his own don't show it as clearly.

Congrats! It looks really cool (and BIG). It would be a fun to picture an SVS tube right next to it. :rofl:

[JonW]

Wow, over 500 years they will find this relic and want to know if it was used as a weapon of mass destruction .

Great project and very nice result. (how big is that room??)

Thanks. Yeah, a weapon to crumble houses from within.

For the two walls you can see, left to right, that room is 13 feet (about 4.3 meters). From those windows in front to the back wall behind the camera is maybe 21 feet (7 meters). The room also opens to 3 other rooms with big openings (pocket doors) and one regular door to a hallway. Floor to ceiling is, I think, 9 feet (3 meters)

[JonW]

Wow, that picture really shows how f*cking big that thing is! The pictures Steve has from his own don't show it as clearly.

Congrats! It looks really cool (and BIG). It would be a fun to picture an SVS tube right next to it. :rofl:

Thanks. It is quite large. I didn't really know what I was getting in for. But placed in a corner, it's not too obtrusive.

Actually, I would very much like to see and hear an SVS sub for comparison. When I first hooked this sub up, it was shaking the house pretty good. But I thought it maybe should do more. Because I read about all these people with their $400 SVS subs saying how they collapsed a 25 story building and then induced another earthquake along the San Andreas fault or something. Steve came over, heard my sub, and said it's doing very well. But still, I want to see what the big deal is from a $400 (or even a $2000) SVS for a comparison. If anyone wants to bring one over...

[SteveCallas]

Great work Jon, the pine caps and plate really came out well. When I was at Jon's giving it a listen, I loved the fact that his restriction isn't neighbors, rather, it's fearing for the structural integrity of his house :B The amount of clean energy that thing was putting into his room was just amazing, especially with Master and Commander and Polar Express.....damn I need a house :cry:

[HMenke]

I love the way it looks in your room! The coolest thing about your new sub is now you won't be missing anything in the program material. If it is in there, and you deliver it to the sub, you will experience it.

[ThomasW]

It's really a drag when people wimp-out and give in to the SAF/WAF pressures and end up building a little tiny sub...:roflmao:

[chasw98]

Very cool, Dr. Jon! You should probably order some spare panes of glass now so you have them on hand when they blow out from the pressure induced! These Callas "daleks" are starting to take over the world! Great job, I like the wood work.

[HMenke]

Possible names:

Pillar of Power
Pile Driver
Saturn V
Hyperbaric Cylinder

[---k---]

Wow! You're picture makes it look much bigger than I remember Steve's being. That is just too cool.

I wouldn't worry about your house. You got insurance right?

[JonW]

-k--
I hadn't thought about house insurance. But if I had to file a claim, how would I hide this thing away from the inspector? :P

Possible names:

Pillar of Power
Pile Driver
Saturn V
Hyperbaric Cylinder

I like it. My girlfriend has been talking about decorating it for each season: Hang ornaments off it and put presents under for Xmas, eggs on Easter, tape colored leaves on it for fall. When we weren’t sure if it would stand up straight, she called it the “Leaning Subwoofer of Pisa.” At one point, she wanted to cover it with plastic grass. And she’s also threatening to cover it with white lace and call it the “Wedding Woofer.”

It's really a drag when people wimp-out and give in to the SAF/WAF pressures and end up building a little tiny sub...:roflmao:

Sorry I let you down, man. :P

[chasw98]

And she’s also threatening to cover it with white lace and call it the “Wedding Woofer.”

Is "Here comes the Bride" available in SACD or DTS? :E

[SteveCallas]

But if I had to file a claim, how would I hide this thing away from the inspector?

Tell them you have asthma and it is an air purifier :roll:

[ssabripo]

Very nice Jon!

man, Steve's head must be as big as a .....boilermaker!! hehehe. Lots of folks doing Callas-esque sonotubes. Awesome! Maybe I outta get into one too....hehehe. No, but seriously, looks awesome man. Post more pics!!!

[JonW]

OK then, a couple pics from building:

Mounting the driver in the bottom cap:

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The top cap with the port:

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[smirnoff]

Way to go man! That thing is EPIC!!! ;x(

[chasw98]

Did you glue your caps in or force fit them a la Steve? I don't think you need to worry about your speaker wires buzzing

[bobgpsr]

I like Ryan's idea (mentioned elsewhere) about involving the ME or CE schools in coming up with a floor decoupling solution. Of course if they aren't interested you could always try the MET or CET schools. They do practical stuff :P Seriously you could get four heavy 12" to 18" square paving blocks to put under the sub to make a heavy platform before layers of foam and a flat piece of MDF. I found something like that to be useful in decoupling my PCU on a wood joist floor (just one paver, foam and a 20" circular particle board cutout).

I feel very low freqs through the concrete basement floor with my DIY Tumult.

I'll bet you can play it at high levels on Sat nights and just blend in with the other student houses. Or maybe that is just in West Lafayette!

Isn't it nice to know that that LF response capability is just there -- as required. Nice work Jon, Steve, and Gudrun.

Bob

[David G]

Hats off for a no compromise design.
I guess if you covered it in a beige cloth it could blend into the decor a little more

[Mazeroth]

The best part is that you used 8" sonotube for your PORT!

Congrats on a killer sub! Don't even worry about an SVS touching that beast. Your sub would eat ANY SVS alive!

[JonW]

Hey Guys,

Thanks again for the compliments.

Chasw98- Yeah, the caps are forced in. I was quite concerned about keeping the seal air tight. So the caps are a little too big and didn’t slide all the way down into the tube. It’s the only visible thing about the sub that isn’t perfect. But it’s DIY, I guess.

Bobgpsr- I would think that the best decoupling solution might be another Avalanche 18 on the floor, firing up, to cancel out all the current driver vibrations. But I don’t know about any of that practical stuff. So another driver just for decoupling might be a bit much. Regarding the pavers and foam, I'd think it really depends on finding the right foam. I'm not sure how you'd pick that ahead of time.

DavidG- I’ve actually started making some fiberglass panels for room treatments. I covered them with unbleached muslin and it almost matched the room perfectly. You hardly even notice they’re there.

Mazeroth- Thanks. I’d still like to hear an SVS sub, though, for comparison. Maybe a bottom and a top of their line. If I could get someone to bring one over… My sub isn’t too portable.

[steve nn]

Talk about nice work! That looks incredible and no doubt sounds incredible...nice job with the wood also.

The best part is that you used 8" sonotube for your PORT!

That's what I thought..I'm going to remember that. It's got to be cheaper than PVC?

[HMenke]

I like sonotube for the port because with wood glue it binds well to MDF.

[JonW]

Yeah, I kind of like the sonotube for the port. It's lighter than PVC (less chance of dropping down) and a little bit flexible. So I just pressed the port into the holes I made for it. The sonotube might be slightly easier to cut than the PVC as well.

However, when I pressed the port into the holes, it was a really tight fit- which you want so it doesn't fall out. So jamming it in there meant I crushed the port end a little and had to trim it down. PVC wouldn't have that problem.

Not sure what I'd use if I were to do it again. 8" PVC might be tough to find. And that might dictate the choice.

[Mark Seaton]

JonW,

I have to say, when I first looked at the picture, I thought someone photochopped something together. Talk about dwarfing those poor little main speakers. 8O

The best part is that you used 8" sonotube for your PORT!

Congrats on a killer sub! Don't even worry about an SVS touching that beast. Your sub would eat ANY SVS alive!

That's actually a literal statement... Any of the SVS tubes would easily fit INSIDE that monster. It could possibly "EAT" two of some of the SVS models.:eating:

Are you another Boilermaker? or just in the region?

[chasw98]

Mark:
I think it is worse than you think. I believe he teaches there

[SteveCallas]

Here is a comparison shot I threw together that should be accurate based on the Ultra's dimensions:

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Volume wise, you could fit just over 5 Ultras in this enclosure.

[chasw98]

Good job, Steve. Kind of gives new meaning to the term "mini".

[---k---]

Steve, that is good. To bad it isn't a real photo - my brain has a hard time not thinking it is a trick.

[JorgenMan]

Here is a comparison shot I threw together that should be accurate based on the Ultra's dimensions:

Image not available

Volume wise, you could fit just over 5 Ultras in this enclosure.

That gives me an idea - it would be funny to see an extended version of the SVS animation, featuring your DIY sub.

[JonW]

Mark:
I think it is worse than you think. I believe he teaches there

Very funny. Worse than you think. :P Yup, I'm a professor here.

Here is a comparison shot I threw together that should be accurate based on the Ultra's dimensions:

Oh, what an adorable, cute, quant, little baby subwoofer that PC Ultra is.

[JonW]

JonW,

I have to say, when I first looked at the picture, I thought someone photochopped something together. Talk about dwarfing those poor little main speakers. 8O

No, it's 100% real. Steve has even seen it in person, to attest. Although it might look to be a little bit more of a stark contrast than it really is. In that photo, the sub is closer to the camera than the main speakers. The main speakers are about 3' tall and the sub is about 7' tall. The photo is from when the sub was finally put together. In actual use now, I have the sub pushed into the corner on the right. The sub looks less imposing there.

[SteveCallas]

After he came across this board while looking to build a new HT, and caught the Purdue references in this thread, it looks like the club will be getting a new member......Jischke says he's game!

[dyazdani]

That's scary - I had one of the original SVS models back a few years ago. It seemed pretty big at the time, guess not so much...

[Mark Seaton]

Very funny. Worse than you think. :P Yup, I'm a professor here.

Fellow Boilermaker here Jon. It's too bad there weren't more professors interested in audio when I was there. A guy I later became friends with started a Purdue Audio Society and had some trouble finding a sponsor. When I was later president of the club we had to find another sponsor and after probing around a bit found that Prof. Meyer in ECE (who I had as a Prof. at the time) was a bit of an audio enthusiast. Some later digging found that he actually had a lot of involvement on some work with JBL(I think) for an early, processed array system. Unfortunately after I left there wasn't anyone to keep the group going. What is amusing is that from that relatively small group, a rather high percentage of people are now employed in the audio business, a few with Harman Int. Apparently one of the current or past designers at Snell is a Purdue Alum. Maybe it has somethign to do with the collection of tech-heads and poor ratio of women, but there is a curious history of audio involvement for a school that has almost no technical course offerings on the topic.

Oh, what an adorable, cute, quant, little baby subwoofer that PC Ultra is.

This is exactly the type of thing I like to point newbie DIYers to when they make that bold statement... "I don't care about size, I want the best performance!" :roll:

[steve nn]

This is exactly the type of thing I like to point newbie DIYers to when they make that bold statement... "I don't care about size, I want the best performance!"

Mark would you care to elaborate on what your asking for those that are a little slow to the gate? 8)

[---k---]

Jischke says he's game!

NO WAY!

The thought of that has me acting like a freshman. Our President has a 7' sub that can eat your president.

All of us Boilers should meet up for a football game this fall. That would be pretty cool.

[SteveCallas]

Various interruptions and clashes in schedules have held us back so far, but don't forget we still have that pre/pro vs reciever test to get done. I know everyone's musical selections inside and out by now :B

[Mark Seaton]

Mark would you care to elaborate on what your asking for those that are a little slow to the gate? 8)

I wasn't asking anything, but rather a picture like JonW posted is often needed to snap those saying "I don't have size constraints" back to reality. At some point we have to give a little merit to power density. An IB either easily wins or is in dead last for such a comparison, depending on how you measure.

[JonW]

Mark-
Glad to see another Boiler. And thanks for the club history. I hadn’t even looked for an audio club or thought that there might be one. I’m not an electrical engineer, so I know very little about all the details of speaker design. All of what I know comes from this web site and a couple books I’ve read. My next project will probably be trying to build those Modula MT’s and see how that goes.

This is exactly the type of thing I like to point newbie DIYers to when they make that bold statement... "I don't care about size, I want the best performance!" :roll:

That’s what I said before starting this project. No regrets. Although I must admit that when the sonotube showed up to my door I did have a thought of “Ummm… what am I getting myself into?” Now seeing how small those SVS subs are, relatively speaking, makes me even happier with my no compromise big sub. I’m happy with the output, but not sure I’d be happy with too much less. And, at least based on size, the SVS output must be much less. Even though everyone says they are so amazing, can crumble large buildings, hasten continental shifts, etc. I looked into IB’s. But I just wasn’t willing to cut a hole in my 100 year old house.

All of us Boilers should meet up for a football game this fall. That would be pretty cool.

I’m happy to host at my place.

Various interruptions and clashes in schedules have held us back so far, but don't forget we still have that pre/pro vs reciever test to get done. I know everyone's musical selections inside and out by now :B

Indeed. We’ve got to do that soon.

[SteveCallas]

I’m happy with the output, but not sure I’d be happy with too much less. And, at least based on size, the SVS output must be much less

Keep in mind, even though you may have the amp and master volume at max, the sub is amp limited, so only if you see a red clipping light flash will you know you have started reaching the design's limits (and even then, the sub could handle a bit more power anyway ). While the canon blasts were simply awesome in your room, believe it or not, it still has more to give. I believe the limiting factors at this stage are the sensitivity of the Forrests and the sensitivity of the K1. I doubt you want to go much louder than the canon blasts for the sake of your home 8O , but if you did, those would be the areas to look in to.

[bobgpsr]

All of us Boilers should meet up for a football game this fall. That would be pretty cool.

Yes, It has been just too long since I've been back to campus --- heard that it is really different now and you can't even ride a bicycle between Music Hall and and the Student Union. I left my first DIY 7 ft^3 bass reflex (a super party animal when combined with a smooth clipping tube amp) sitting in the parking lot when I left for Iowa in '75..... :cry:

Bob

[JonW]

I left my first DIY 7 ft^3 bass reflex (a super party animal when combined with a smooth clipping tube amp) sitting in the parking lot when I left for Iowa in '75..... :cry:

Yeah, thanks for leaving that behind. We slapped a clock on the face and called it a clock tower. The bass on campus is phenomenal. :T

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[JonW]

Keep in mind, even though you may have the amp and master volume at max, the sub is amp limited, so only if you see a red clipping light flash will you know you have started reaching the design's limits (and even then, the sub could handle a bit more power anyway ). While the canon blasts were simply awesome in your room, believe it or not, it still has more to give. I believe the limiting factors at this stage are the sensitivity of the Forrests and the sensitivity of the K1. I doubt you want to go much louder than the canon blasts for the sake of your home 8O , but if you did, those would be the areas to look in to.

Yeah, the sub could probably do a little more. The main speakers play plenty loud for my tastes. But I don't think there's any need for more bass at this point. I'm already worried about the house. And it seemed to me like the Carvin amp gave the sub a little (not tons but a little noticable) more oomph than the K1. So I could get one of those boxes for the K1 to up the sensitivity. But no need. The only thing I might consider would be more subs to get stereo, for music. But I'm not as crazy as you, to want more than one of these monsters. I'm just a wee little bit crazy, enough to have one. :twisted: