Sonotube Size Suggestions?

[JoeyG]

Had to take a break from the sonosub construction to finish a few jobs, but I am back on it and have a couple questions as far as mounting the driver.

Like many with RL-p 15 mounting holes not lining up, was there a way that seems to work best in dealing with this issue? I was going to exacto knife the hole out, but then thought it may start a tear in the surround foam, so I am thinking the best way is to pre-drill the holes through the mdf where the speaker holes line up, and then just allow the screw (or whatever long bolt matches up to the t-nuts) to work its way through the surround foam? Any input would be great as I have not exacto or drilled through the surround foam yet...

The removable rubber ring that acts as the speaker seal, I'm taking it the driver mounting screws/bolts heads will tighten up against this on the face(vs. tightening the screws/bolts to the surround foam/metal speaker frame), since it is solid rubber? Is there a certain size bolt that will not pull through the rubber surround? I hear of people using 1/4" t-nuts so I wanted to confirm this is correct before I take a step backward in the build process.

Thanks!

[SteveCallas]

Some people have mentioned that the metal frame on the RLp15 might be too narrow to allow for widening the holes a bit to fit 1/4" bolts, so you'll want to check that first. If you can fit them, I'd go that route with the 1/4" t nuts.

If not too late, I'd maybe trim a couple inches off the port length - though a 36" port is in use with no problems, and I can't justify it, the constant talk of port resonances I've been hearing in the last few weeks has spooked me a bit :B If not, no worries.

[JoeyG]

My current production state is that the speaker ring/lower cap has the dowels in place and screwed together ready for the speaker to be mounted, all other pieces are separate still so I can take a couple inches off the port length if needed, couple meaning 2" Steve?

Any advice on the mounting hole and surround foam issue?

[ThomasW]

Any advice on the mounting hole and surround foam issue?

Most people use an Exacto knife to trim the surround away from the precut holes in the frame

[SteveCallas]

so I can take a couple inches off the port length if needed, couple meaning 2" Steve?

Correct.

[JoeyG]

So the speaker is mounted, but I'm not sure if this is the correct mounting method because the bolt, and pressed surround rubber seem to be close to the foam donut that moves in/out during use. I definitley do not want to only have this speaker for a month then have the bolt grind a hole in the foam!

Would it be better to use allen bolts and mount to the speaker frame instead of the way done in the image?

Thanks,
Joey

[ThomasW]

The idea is that the top section of the rubber gasket is supposed to hide the bolt heads.

The easiest way to do that with a large bolt is lift the edge of the rubber out of the way and run the bolt down, then let loose of the gasket letting it flop back in place. That way the bolt heads are covered.

[SteveCallas]

Man, soundsplinter really doesn't give you much space at all. Thomas - looking at the picture, if he tightens the bolts against the metal frame, lowering them a bit, he will definitely come in contact with the surround. I don't know why they made the hole so close. I'd probably leave it as is.

[ThomasW]

It's the standard spacing on the Venezuela frame. I remove the rubber ring and use the cast alu clamps designed for pro-sound drivers = problem solved.

[JoeyG]

Thomas,
Can you post a link for the clamps, I believe I know what you are talking about but I would like to do this right the first time.

When I had gone to the hardware store, I was comparing bolts, one size down from 1/4" looked so weak, I went with 1/4 and drilled the holes out on the speaker frame carefully and widened the mount hole to the outside, while using matching t-nuts on the opposite end.

Thanks for the help!

[ThomasW]

http://www.usspeaker.com/speaker%20hardware-1.htm

Scroll down to where you see the clamps

[JoeyG]

I think those will work even with the blocks I previously glued inside for more thread bite...

Thanks Thomas, that was a big help and probably saved my speaker from turning into a useless conversation piece!

[Dennis H]

Joey, try "socket head cap screws" i.e. bolts that take an Allen wrench. The head is smaller and round rather than hex shaped. A local hardware store should have them or you can get them from http://www.mcmaster.com .

[JoeyG]

Yea! grew up using allen bolts as a bmxer, these would bolt into the speaker frame but may harm the surround foam, some areas only have about 1-2mm of surface between the mount hole and foam end to the inner part of the speaker.

I will try these, and if it looks like the clamps would be safer, I'll get out the router and make room for the clamps.

Thanks for the input Dennis

[JoeyG]

Thomas, with the RL-P15, the rubber surround that comes with the speaker, do you think creates a good enough air seal?
I believe you mentioned something about tossing it and using a different foam for the seal?

Thanks

[ThomasW]

Where the driver is hidden I toss the rubber ring. If the driver is exposed I use the ring.

[JoeyG]

What do you use in replacement of the rubber ring for an air seal?

[RandyMidd]

You can use weather stripping.

Example, FrostKing brand, self stick, 3/16" thick vinyl foam, moderate compression weatherseal - available at HDepot.

I'd match the width of your driver flange surface so you don't put an uneven load on it while tightening with those big 1/4" screws you have there.

Example, if the flange surface is 1/2" wide use 1/2" wide material or two 1/4" wide gasket material...it's OK if material is wider than the flange of the driver - since no one will see it. Tighten the bolts like a car tire - a little bit at a time using a star pattern - and don't overtighten because it's really not a car tire.

Don't use caulk or some other permanent material that impedes removing the driver should you need to in the future.

[JoeyG]

Randy that was a big help, I'm off to HD.

I didn't go with the bolts last shown because I didn't like the way they pressed the rubber surround into the foam surround.

In the end, the best option in my opinion was to exacto a small amount of surround foam around each hole and drop 'allen bolts' through since the bolt-head space will not interfere with the surround foam.

Thanks again, my progress has been a bit slow due to that darn mortgage every month...

[RandyMidd]

Thanks again, my progress has been a bit slow 

You're faster than me...my problem is too much work...

I suppose you can also cut off that portion of the gasket material (that came with your driver) you need for a seal...whatever is easiest...

[JoeyG]

Thats funny, chopping off the top half of the rubber surround crossed my mind because I wasn't sure if the rubber that came with the RL-P had more of an aesthetic purpose (ie. ThomasW not running it and replacing with other material) rather than functioning as an air seal. If the rubber that comes with it is good enough, I would consider just running that...

[ThomasW]

If the driver is rebased, then the cosmetic rings seal pretty well. If it's a surface mount I put a layer of rope caulk or weather stripping under it.

[vitod]

The rubber should be enough.

[JoeyG]

I am about to wire my dual 2 ohm RL-P15, but am not exactly sure how to wire for a 4 ohm load, are there any diagrams online that would explain? I looked online but have not come across any quality information...

Thanks,
Joey

[chasw98]

I am about to wire my dual 2 ohm RL-P15, but am not exactly sure how to wire for a 4 ohm load, are there any diagrams online that would explain? I looked online but have not come across any quality information...

Thanks,
Joey

Look here http://www.crutchfieldadvisor.com/S-...rs_wiring.html
They have just about every way to wire a speaker or speakers together.

Chuck

[JoeyG]

Exactly what I needed, Thanks Chuck. The speaker should be mounted this weekend and ready for the tube...

[JoeyG]

It's been awhile but I am back building the sonotube. I have all the pieces now and am connecting the receiver to the carvin 900 amp. My receiver (Sony STR-DE697, which will be replaced soon with a Denon AVR-2308CI) has a Monaural output for the sub, but the inputs for the sub on the Carvin amp are TRS and XLR. Any tips on what cable to get to connect the two? Or how to connect the two?

Thanks!

Joey

[---k---]

You can use one of these:

http://www.musiciansfriend.com/product/Hosa-XRM-105-5-RCAXLR-Male-Cable?sku=333031

or RadioShack sell a RCA ->1/4" Mono adapters.

[JoeyG]

Awesome, I picked up the 1/4" - RCA at RadioShack but I suppose the XLR > RCA would have better sound because of the cable thickness? Is this correct?

I was researching the Denon receivers and some posts here talk about the 2808CI and 988CI, they seem like the exact same receiver (and same price), except 988 has the learning remote? Any thought's if the 2808CI would be better or worse?

Thanks for all the help!

Joey

[---k---]

The difference between the cable and adapters probably will be slim, especially for a sub.

I'm not really up on receivers anymore. If they are they have the same feature set, then they are likely the same receiver - just intended for different resellers. The 2808 is meant for high-end dealers, while the 988 is intended for big-box stores. CI originally referenced that they were for "custom installs". You probably would get better answers in the other forums.