Sonotube Size Suggestions?

[ThomasW]

have you used these clamps with this driver? I'm asking because some important dimensions weren't given at that website.

I've used the clamps made by Electro Voice on drivers that have the Venezuela frame. I don't own any RL-p15"s, but that's neither here nor there, since the same Venezuela frame is used by dozens of manufacturers.

The clamps in the link appear to be a copy of the EV clamps. If you have specific technical questions about the clamps they sell, you better ask US Speakers.

[Bent]

one of my 15" RL-p's had it's surround glued askew - but it survived the soldering iron trick quite well

the other rl-p was assembled dead-on.

[SteveCallas]

I'd enlarge the holes a bit towards the outer edge of the metal frame, put the rubber gasket back on, and use bolts. Should solve the problem.

[RandyMidd]

I'd enlarge the holes a bit towards the outer edge of the metal frame, put the rubber gasket back on, and use bolts. Should solve the problem.

The part of the surround that's glued to the driver frame is so poorly placed on these that if I go to 1/4" bolts I'll have only about 1mm of surround material left in some places for maintaining the seal. For comparison a little 10" woofer I have on hand has about 10mm. If I'm careful and patient with the drill in trying to open up the holes towards the outside of the frame I would come out with more material left for a seal it's true ...it's a bit risky.

The driver gasket (I'm pretty sure) wasn't meant to be used like you did but on the other hand you proved that it could be. Have you experienced any trouble with your gasket (on the front side) compressing over time around the bolt heads?

At this point I'm planning to implement one of Thomas' suggestions...

I appreciate all the comments...

[SteveCallas]

My driver is mounted in a down-firing position, so the rubber gasket is essentially forced right up against the metal frame. I guess if you aren't going for a down-firing configuration it might not work as well. But I haven't had any problems.

[w8liftr]

If you stick to 260 effective liters (meaning that much is left after subtracting end cap and port volume), your 6" port should be between 28" (~16hz tune) and 33" (14.8hz tune). That design should give you the best results in terms of overall balance and sound quality, in my opinion at least.

I really believe in this design, I built two :W One would be very impressive.

[JoeyG]

Since a 33" port can reach 14.8hz, that seems reach lower sounds... is there an advantage to tuning it to be ~16hz with a 28" port?

My guess is that music would sound better with a 28" port?

[ThomasW]

One won't 'hear' a difference between 14.8Hz vs 16Hz.

But if you have the space, the longer port with a lower tuning is the better choice regardless of whether the sub is used for music or HT.

[SteveCallas]

My guess is that music would sound better with a 28" port?

Actually the lower tune would give better sound quality. While Thomas is right in that you won't hear the difference in extension, the lower tune pushes the "bad" side effects of using a port into even lower frequencies where hearing sensitivity is extremely poor. Since most of the bad effects aren't that noticable to begin with even in higher bass frequencies, pushing them down into the teens and single digits basically eliminates the chances of them being audible entirely. And until the port output starts coming into play, the driver is almost 100% responsible for all output, so a lower tune keeps the driver responsible for the bulk of the output over a larger range, and the "free" output can be reaped in the really low regions where it's needed the most. I've said it many times, but it's like having your cake and eating it too.

Drawbacks are going to be size and reduced headroom. You also have to make sure you select a driver that can handle being tuned very low.

[JoeyG]

I am going to use a SS RL-p15 D2 as long as I can get my hands on one, hopefully this week (which should be able to be tuned that low right?).

When you say 'tuned', you mean the port length 'tunes' the frequency right? or are you talking about other external hardware to tune the driver for a certain frequency?

I have a 16 foot ceiling in the front room, so headroom shouldn't be an issue, but would 5" of more port increase the 20" Sonotube height that drastically? (or were you referring to speaker headroom between the magnet and the port?)

[ThomasW]

When you say 'tuned', you mean the port length 'tunes' the frequency right?

Port length and box size determine the tuning frequency.

or were you referring to speaker headroom between the magnet and the port?)

One should design a sub like a car motor, you don't want to run the motor at redline all the time, you don't want to run the sub at it's max output. So when designing anything design in extra capacity = headroom

[SteveCallas]

I have a 16 foot ceiling in the front room, so headroom shouldn't be an issue

I'm being sincere when I say that I mean absolutely no harm, but that is one of the funniest things I have ever read on this forum :rofl:

I was referring to headroom in the way Thomas explained, basically maximum output capability.

[JoeyG]

Just showing my true colors I guess haha...I am new to this and am sure to provide some laughs along the way...while hopefully getting this this sonosub done right!

[seattle_ice]

Hey, speaker design and a comedy routine - however unintentional. This forum just never lacks for interest.

[JoeyG]

Planning on cutting some circles this weekend, is there a certain MDF wood composite that seems to work best for a sonotube?

[ThomasW]

Planning on cutting some circles this weekend, is there a certain MDF wood composite that seems to work best for a sonotube?

It's all pretty much the same.

[JoeyG]

Got a small section of Sonotube to take with me on my trip so I can get the caps cut and the driver is on its way, but I had a hard time finding 6" PVC port. In another forum I saw someone had used 6" Sonotube for the port, is there any difference in audio quality or possible issues if I were to run Sonotube for the port compared to schedule 40 PVC?

[kickngas]

port options

Joey,
I am building a Sonosub, and I am using heavy duty mailing tubes for the port....found here: http://cgi.ebay.com/6-x30-Yazoo-XHvy...1QQcmdZViewIte

I had to buy 4 of them even though I only need two for this project. Check them out. You can check with a local mail express or the like and see if they carry a similar product(U-line is another brand).
Steve

[nick77]

Got a small section of Sonotube to take with me on my trip so I can get the caps cut and the driver is on its way, but I had a hard time finding 6" PVC port. In another forum I saw someone had used 6" Sonotube for the port, is there any difference in audio quality or possible issues if I were to run Sonotube for the port compared to schedule 40 PVC?

I found this product at an irragation supply house for about $11 for 7' long and 6" wide.

[JoeyG]

So I'm in Oregon, found a place that has 6" irrigation pipe, but have different types that are bigger and smaller OD sizes.

When referring to the 6" port, are you guys referring to the inner diameter?

Thanks

[SteveCallas]

Yes, 6" is the ID. If they have anything with a slightly larger ID, say between 6" and 7", that would be even better - just post what ID you use and we can readjust the needed length for you.

[JoeyG]

Steve, the tube I ended up with is 6 1/4" I.D. and 6 5/8" O.D.

Thanks for the help

[SteveCallas]

Ok, the range of port length I'd use increases to 30-36".

[JoeyG]

Since it's a larger diameter than 6", I was figuring the port length would be shorter since it is letting more airflow out? guess not...
Either way I lucked out by buying 36" but will have to shorten it a bit because the guy cut the port a bit crooked.

Thanks Steve

[RandyMidd]

Larger diameter = longer pipe

Not that this is necessarily correct but I think of it like this...larger diameter = less resistance to airflow. So to compensate what do you do? Add length.

[JoeyG]

I've got the caps cut, RL-P15 D2 fits nicely, and the 6 1/4" port is cut to 36". I'll post pics when I figure out how because believe it or not I have a question (hehe)...

Anyone know of a decent online volume calculator?

I think this is the most painful moment, working from home, the speaker is just sitting there and I know it has juice as it is enormous in many respects, but...can't play it yet...

[ThomasW]

http://www.online-calculators.co.uk/volumetric/cylindervolume.php

http://www.quux.net/roo/diy/sonosub/sonocalc.html

[nick77]

The design that W8Lifter and myself used via Steves advise was 20" sonotube at 56". The result is awesome house shaking results.

[JoeyG]

That calculator is super helpful, but it didn't have the volume for the RL-P15, only Shiva and Dayton. Is there a place to find the volume for my speaker? I checked the Sound Splinter page and I didn't see it.

Using the default 183 for driver volume, on the calculator page, gave me approx. 55" sonotube height

Thats what I was keeping in mind Nick, sounds like you are satisfied....

Thanks

[ThomasW]

That calculator is super helpful, but it didn't have the volume for the RL-P15

Not surprising. You'll find the displacement listed on the RL-p15" specs page far right hand column.

[nick77]

That calculator is super helpful, but it didn't have the volume for the RL-P15, only Shiva and Dayton. Is there a place to find the volume for my speaker? I checked the Sound Splinter page and I didn't see it.

Using the default 183 for driver volume, on the calculator page, gave me approx. 55" sonotube height

Thats what I was keeping in mind Nick, sounds like you are satisfied....

Thanks

Satisified? More like blown away! Hehe

[JoeyG]

So here is the speaker cap, two 3/4" pieces of MDF. The outer cap is routed in 1/2" so the speaker sits flush and screws/bolts will have an inch of thread leading into 20" diameter cap.
I've seen some people on these forums add 3/4" blocks and glue them to the inner 20" cap where the screws will come through to give an extra 3/4" thread bite.

Is this necessary? and should I heighten the sonotube if I put these in since the blocks will be taking up space?

[ThomasW]

MDF has no strength, so it's a good idea to use something for the screws to 'bite' into.

There's roughly a 10% fudge factor when building a sub so accounting for little things like the blocks isn't necessary.

[JoeyG]

As far as Fiberglass insulation goes, I found people using R13 or R30, any opinions on what will work most efficiently?

[ThomasW]

You don't need anything as thick as R30 for a ported sub.

[nick77]

As far as Fiberglass insulation goes, I found people using R13 or R30, any opinions on what will work most efficiently?

I had r-30 around from another project so I just peeled layers off to complete sonotube.

[JoeyG]

Awesome, thanks for the images Nick. I guess I'll pick up the r13 then.

[oxcartdriver]

How stable is the fiberglass insulation? Does it stay on the walls or is there any possiblity of insulation exiting the port tube? I'm ordering parts now for a 300L, RL-p15, 8in port 33.5in port length.

I'm personally leaning towards foam insulation, but always wondered about fiberglass insulation and keeping the fiber glass in the cabinet.

[ThomasW]

A port is not an acoustic cannon continuously blowing high velocity air into the room. The air in the port moves back and forth according to the motion of the cone.

You'd be exposed to a thousand times more fiberglass when you install it in the sub, than you'd ever experience standing beside the operational port.

Having lived in Colo for the last 45 yrs (parents moved here when I was in the 8th grade); my thought is that the wind blowing over the state's numerous uranium mine tailings or the 10 sq miles of tailings at the ClimaxMoly mine outside of Leadville, is more problematic to one's health than the fiberglass exposure from a ported sub.....:wink:

However, if you're paranoid of fiberglass in the sub, cover the inside end of the port with grill cloth (that will slightly change the effective tuning) or just use acoustic foam.

[chasw98]

Having lived in Colo for the last 45 yrs (parents moved here when I was in the 8th grade); my thought is that the wind blowing over the state's numerous uranium mine tailings or the 10 sq miles of tailings at the ClimaxMoly mine outside of Leadville, is more problematic to one's health than the fiberglass exposure from a ported sub.....:wink:

Let's see, eigth grade = 1X years old + 45 years = geez, what a geezer. And the way you talk about jon!

And what about all those children playing in the oil shale near Craig? They seem like pretty hardy youngsters :T

[ThomasW]

Hey I'm so old I'm almost petrified....Jon's just a punk kid compared to me... :B

There are so many inherent environmental toxins (everything from uranium dust to heavy metals) throughout the mountains of Colo. I'm surprised the newborns don't have 2 heads.... 8O

We're aided in our contamination by the Canadians. There are spent gold mines here where they're using cyanide to leach gold from the tailings of the mines. This is an open pit operation... :M

[nick77]

How stable is the fiberglass insulation? Does it stay on the walls or is there any possiblity of insulation exiting the port tube? I'm ordering parts now for a 300L, RL-p15, 8in port 33.5in port length.

I'm personally leaning towards foam insulation, but always wondered about fiberglass insulation and keeping the fiber glass in the cabinet.

I just used spray adhesive when installing insulation and all seems well.

[Jerm357]

That calculator is super helpful, but it didn't have the volume for the RL-P15, only Shiva and Dayton. Is there a place to find the volume for my speaker? I checked the Sound Splinter page and I didn't see it.

Using the default 183 for driver volume, on the calculator page, gave me approx. 55" sonotube height

Thats what I was keeping in mind Nick, sounds like you are satisfied....

Thanks

I think the driver volume for the RL-P15 is 362.88 cubic inches.

[JoeyG]

Thanks for the driver volume, sonotube still measures 56" and thats what I've got in the garage.

Any advice on speaker wire gauge? The Carvin HD900 accepts up to 7 gauge...

[ThomasW]

The gauge of wire used depends on the length of the run being used.

Most people use 10-12 gauge