My DIY Sonosub project

dane_peterson

Just wanted to let you guys know that this project is officially underway. I've gotten a hold a local Cemstone that has plenty of 20" diameter Sonotube in stock, and can cut to size. My friend and I will be making a pair of these together. Anticipate this thread to have lots of photos, and probably take a couple weeks to complete.

Current plans are:
15" SoundSplinter RL-P15 dual 2
Behringer EP1500 amp (1400w @ 4ohms bridged)
Effective volume: 230L
Total dimensions: 65" tall, 20" diameter with a 22" baseplate.

Plenty more to come!! Suggestions for anything along the way are more than welcome, as it's my first sub/speaker build.

Systems

Looks like a recipe for an excellent sub.At what frequency are you going to be tuning the port 15hz ish?

dane_peterson

Yeah, somewhere between 15-17 hz. I'm not well-versed on tuning, but this sounds like the appropriate size for my driver.

Here's a pic next to the tubes. The shorter is 60", taller 65". They were already cut at that length, and I figured a little extra wouldn't hurt.

The second pic is a bunch of 2' scrap I told them I'd take off their hands. Figure there's got to be something I can use it for, if not a sub.

dane_peterson

Latest update... nothing exciting. But I did place an order from Parts Express. Have 4 sets of speaker mounting hardware and 2 sets of binding posts for the two subs:
http://www.partsexpress.com/pe/showdetl.cfm?&Partnumber=260-775
http://www.partsexpress.com/pe/pshowdetl.cfm?&DID=7&Partnumber=091-340&scqty=1

jakelm

Dane, I dont know if anyone has mentioned this, but Ben has a great thread about his Sono project. Alot of good info. Your in for a great project.

http://www.polkaudio.com/forums/showthread.php?t=51533

dane_peterson

Thanks Jake.
One problem I've run into is that I can't use any of the necessary programs to enter parameters as I use a Mac. I might have to over to the parents' house or something to get this dialed in accurately.
Plan is to go pick up the MDF today, though I probably won't start cutting. Not looking forward to that part of it.

DollarDave

dane_peterson wrote: »

Thanks Jake.
One problem I've run into is that I can't use any of the necessary programs to enter parameters as I use a Mac. I might have to over to the parents' house or something to get this dialed in accurately.
Plan is to go pick up the MDF today, though I probably won't start cutting. Not looking forward to that part of it.

Try this, it's browser-based -

http://www.the12volt.com/caraudio/boxcalcs.asp#por

MikeC78

DaveMuell wrote: »

Try this, it's browser-based -

http://www.the12volt.com/caraudio/boxcalcs.asp#por

That's a very nice tool, thanks Dave!:)

Good luck Dane; I can't wait to hear the outcome, I'm very sure it will be a positive one.

dane_peterson

Got the MDF today, and cut them into 2'x2' sections. My brother bought a circle jig, so we tried cutting a circle with that. It worked all right... but not great.
My brother is going to return the jig and we're going to get a nice router bit instead. We'll use a rotating guide to get it nice and shapely.

Also, I'll be tuning this beast to an impressive 14.5Hz.

jakelm

Dont tune it too low..Dane, you will be dissapointed. Tuning low looks great on paper, but sounds terrible in most rooms. Floppy, a ton of nulls, and less headroom.

I personally would never tune lower than 18hz, but thats just me.

dane_peterson

Yeah, I was hesitant to tune it that low, but it sounds like that's the ideal tuning after reading through some more DIY threads. I'll see if I can't find those threads to provide reference if anyone else ever wants to attempt this.

Here:
http://www.avsforum.com/avs-vb/showthread.php?t=726584

dane_peterson

Latest news...
In cutting the endcaps today, we managed to completely break my brother's router. We have 5.5 more endcaps to cut, then do the inside cuts, sand, paint, order drivers... lots of work left.
Behringer has been here for a few days... just chilling on my stand for probably a couple weeks before I can get everything connected.

Face

How do you plan on attaching the endcaps?

dane_peterson

We will be gluing the three MDF circles together (two inside, one on top w/ overhang) and use liquid nail to seal the enclosure.
I'm considering using an air stapler to secure things a little more, but I'll decide if that's necessary when the time comes.

dane_peterson

Expect some more updates this week, boys and girls! We're going to try to buy a new router and blitz the rest of the cutting over the weekend.

ben62670

If you need any help I am here. As stated above I would not tune below 15.
20 is very good, and typically gives a flatter response.

dane_peterson

Ben,
Maybe you could be of some assistance. I'm a Mac user, so can't use the detailed calculators available for free download. If I provided you some specs, could you establish some recommended dimensions for certain tunings?

ben62670

dane_peterson wrote: »

Ben,
Maybe you could be of some assistance. I'm a Mac user, so can't use the detailed calculators available for free download. If I provided you some specs, could you establish some recommended dimensions for certain tunings?

Yes Sir. I have already been playing with your design. WinISD does more extensive power and frequency curves, and sonosub does a much better design on the measurements.

ben62670

Use the 60x20 tube, and it will yield 9.75cu ft.
The port use 6" PVC with an over all length of 15" for a 20hz tune, or 30" for a 15hz tune. I would try both. I checked the charts with both ports, and the 20hz was much flatter, and also had 6db at 20 over the 15hz tune. On paper I had similar results with my project, but liked the longer port more, but my drivers fs was slightly lower. After final assembly put some depends on, and fire up chapter 12 or 13 of War of the Worlds. Oh yeah make sure sentimental items are secure. Like family portraits, and fine china.

dane_peterson

Would a 22.5" port be the best of both worlds, or should I do one or the other?

Thanks for the help, btw. If you could post up snapshots of the FR graphs, that'd be fantastic.

Additionally, I was considering getting a BFD to help alleviate some bumps in the response. Thoughts?

ben62670

If you get the port right you don't have to worry about manipulation the signal. With effects like room gain, and placement the 2 ports will do all the controlling nesesary. You just have to figure out which one would be better. You could allways try three different lenghts. It certainly wouldn't hurt.
Enjoy Ben

shadowofnight

You could always go with an 18" radiator ...also zero port noise. These also have more excursion then needed to handle your driver ( 3 INCH not mm p-p Xmax ) . http://www.creativesound.ca/ They just became available and are shipping....reasonable price too. You know how us polk guys ( And gals ) love radiators The web page was a bit slow to load this morning...so it will eventually load...on top of page.

Here are the T/S parameters...2 to choose from for tunability ( Just a basic mass ( Weight ) change to lower the Fs )

PR1816 PR1821

Fs: 4.2hz 3.651
Qms: 67.62 67.72
Vas: 1840L 1840 L
Mms: 1600g 2100g
Cms: .9mm/N .9mm/N
Sd: 1200 sqcm 1200 sqcm
Xmax 3" P-P 3" P-P

jakelm

dane_peterson wrote: »

Would a 22.5" port be the best of both worlds, or should I do one or the other?

Thanks for the help, btw. If you could post up snapshots of the FR graphs, that'd be fantastic.

Additionally, I was considering getting a BFD to help alleviate some bumps in the response. Thoughts?

22.5" port would yeald around 17-18hz. Which is exactly where I would have it.

ben62670

shadowofnight wrote: »

You could always go with an 18" radiator ...also zero port noise. These also have more excursion then needed to handle your driver ( 3 INCH not mm p-p Xmax ) . http://www.creativesound.ca/ They just became available and are shipping....reasonable price too. You know how us polk guys ( And gals ) love radiators The web page was a bit slow to load this morning...so it will eventually load...on top of page.

Here are the T/S parameters...2 to choose from for tunability ( Just a basic mass ( Weight ) change to lower the Fs )

PR1816 PR1821

Fs: 4.2hz 3.651
Qms: 67.62 67.72
Vas: 1840L 1840 L
Mms: 1600g 2100g
Cms: .9mm/N .9mm/N
Sd: 1200 sqcm 1200 sqcm
Xmax 3" P-P 3" P-P

Most PR's have to be mounted vertically. Would be fun in in box:)

shadowofnight

ben62670 wrote: »

Most PR's have to be mounted vertically. Would be fun in in box:)

That is generally true...but these new " Super " radiators being made recently are designed to be mounted in any direction...they have Zero Sag. I talked to both manufactures ( The other being TC Sounds ) and both said their radiators were designed in that manner. I am using 2 of these http://www.audiopulse.com/products/passive-radiators/vmp In my mother of all subs build right now.....they are being mounted as both downfiring ( As per TC Sounds recommendation ) with the active driver
facing forward.

They also linked me to this great little webpage to determine if your driver or radiator is sagless and suitable for horizontal mounting. http://www.subwoofertools.com/forum/sag.htm

ben62670

jakelm wrote: »

22.5" port would yeald around 17-18hz. Which is exactly where I would have it.

Hey Jake. I don't have the software one my computer that calculated cone excursion. The problem I had with mine was over excursion at 35hz with the original configuration. It really killed the power handling. Do you still have the software?
Thanks Ben

jakelm

ben62670 wrote: »

Hey Jake. I don't have the software one my computer that calculated cone excursion. The problem I had with mine was over excursion at 35hz with the original configuration. It really killed the power handling. Do you still have the software?
Thanks Ben

Are you talking about WINisd? Or sonosub?

ben62670

jakelm wrote: »

Are you talking about WINisd? Or sonosub?

I have both, but I think the old winISD calculated cone travel, and power handling at said frequency. Good to hear from ya Jake. I was away for a while:(

jakelm

ben62670 wrote: »

I have both, but I think the old winISD calculated cone travel, and power handling at said frequency. Good to hear from ya Jake. I was away for a while:(

I noticed you havent "ben" around. How is that new sub working out?

I do still have the old WinISD.

ben62670

jakelm wrote: »

I noticed you havent "ben" around. How is that new sub working out?

I do still have the old WinISD.

Found it. winISD pro is also free, and it has all the goodies.:)
BTW 20hz is the way to fly. I just don't like short ports for some unknown reason.

jakelm

ben62670 wrote: »

Found it. winISD pro is also free, and it has all the goodies.:)
BTW 20hz is the way to fly. I just don't like short ports for some unknown reason.

20hz does seem to be the magic number. I have both my subs tuned to that. With a rumble filter @ 20hz everything sounds great. No over excursion no distortion.