Sonotube Size Suggestions?

[JoeyG]

(First post) Been here a few days, reading many posts and doing my best to learn about Sonotubes (Many thanks to the pros), and want to build one for my HT sourround. I want to build a sonotube for an RL-p15, but am not sure if that driver will fit my system. I'm reading a lot of negative stuff about Sony, Unfortunately, thats what I am living with currently. Does anyone have any input as far as if this will be too much boom for my current system:

Reciever: Sony STR-DE697 (7.1, 100 w/channel)
http://www.stormlabs.com/Electronics...05211/id/67651

L/R: Sony MF550OH

http://www.sonystyle.com/is-bin/INTERSHOP.enfinity/eCS/Store/en/-/USD/SY_DisplayProductInformation-Start?ProductSKU=SSMF550H&CategoryName=hav_HiFiComponents_Speakers&DCMP=OVERTUREPI_DF&HQS=SSMF550H

Center: JBL Flix2

Surround L/R: Sony SR30 (2 way)

Would an RL-p12 be a better alternative to keeping the sytem more balanced?

Thanks,
Joey

[David Meek]

Hi Joey, welcome to The Guide. :welcome:

You may get more on-point responses in our do-it-yourself forum, but I'll leave the thread here for a while and see what traffic it generates. If it doesn't get much action, I'll move it for ya.

[SteveCallas]

I agree, you'll get lots more help in the DIY forum, but to answer your question, I've helped many design sonosub with the RLp15 D2 with great results. Ideally you would want to aim for ~260 effective liters with a 6" diameter port that is between 28-33" in length, and feed it with 600-1000 watts. I'm 99% sure this sub will blow away any subwoofer expectations you may already have. If you pop in thge DIY forum, you'll see it's a proven design - you may want to ask w8lftr, nick, HMenke, or steve nn about how they are enjoying theirs.

The RLp12 is NOT a good driver to use, it is geared for a very small sealed enclsoure for car use.

[JoeyG]

Thanks Steve,
I've read many of the threads here, especially w8lftr's, and wanted to do that sonotube project, but was unsure if the RL-p15 would fit in my speaker/watt set up.

I am still a bit unsure about everything I need. I am starting with the RL-p15, and possibly the Behringer ep1500 amp (but also looking into other suggestions from threads on this website).

Also, I looked into deleting my thread and posting in the DIY area, but couldn't figure out how. If you could do it for me David that would be awesome, thanks.

Appreciate your help!
Joey

[SteveCallas]

If you don't plan on building dual subs, and will just be using one (and one of these is plenty good), you may want to look into getting a Carvin HD900 running it in bridged mono 4ohm for 900 watts. I would suggest it over a Behringer EP1500 mainly due to fan noise - the Carvin is quieter.

[JoeyG]

We have a WhiteCap here that sells industrial building supplies and they sell something different than Sonotube (they sell ColumnForm), do you know of any differences in tube product/quality? Should I seek the Sonotube brand name?
Here is what they sell:

http://www.whitecapdirect.com/store/worker?request=GetProduct&productID=128CF20&destination=/store/product-v2.0.jsp&from=drilldown

I'm checking out the Carvin Amp, any advice on the cheapest dealer?

I'm reading on many of these threads that you want to tune the sub to a certain HZ (ie. 18hz), will the Carvin HD900 allow me to do so?
It looks as if it only has channel 1 + 2 gains up front, or are those the HZ tuners?

Thanks!

[SteveCallas]

Tube doesn't have to be Sonotube, that brand name has just become the generic reference to concrete forms. My own 28" tube is some Canadian brand.

Carvin only sells direct, so no dealers. The tuning of the sub is accomplished by the diameter and length of the port in correlation to the enclosure volume, it has nothing to do with the amp. The knobs on the front are level attentuators, you use them to basically alter the sensitivity of the amplification.

[JoeyG]

I guess I should clarify that I have set up my car systems through High School (ten years ago), but not much since then. So, I am somewhat new, and really appreciate your time. I'm really looking forward to this project, and like many others here, under a heavy brow of my better half.

I played with winISD a bit and am guessing that will help me find the port length for proper hz tuning then?

Under your advice Steve, my setup would be:
RL-p15 (Sound Splinter)
Carvin HD900 bridged

Sonotube:
20" O.D.
56" tall
6" port (length figured in winISD)
...finer details will be applied

This is my starting point and I guess any advice from here will be greatly appreciated, and reading through the forums to fill in other gaps...

Thanks Steve

[SteveCallas]

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.

[JoeyG]

In reading the HMenke thread and his sonotube, towards the end there was a problem with a hum. Was that due to using the BFD since it did or didnt use balanced cabling compared to the rest of the system.

Since I am starting off bare (RL-p15 and Carvin HD900 amp with no EQ or BFD), I would think the hardware and cabling would not cause that hum?

Just trying to anticipate a headache before I get into the project.

[Paul H]

Most audio system hums come from ground loops, for which both the origin and fix can be somewhat unpredictable. This can be whole separate topic - google "ground loop hum" for some info.

[ThomasW]

If you want a more modest sub using a 12" driver, the TC2+ from www.oaudio.com is a good choice. It's made by the same company that makes the RL-p15".

'Boom' in a sub is a function of one of two things. A poorly designed sub or problems create by room placement.

[JoeyG]

SoundSplinter says RL-p15 D2 is out of stock and there is no phone number so I filled out the online form. Anyone know if these will be available in the near future?

The D4 is in stock, but it won't have as deep of bass as the D2 right?

[ThomasW]

There will be virtually no performance difference between the D4 and D2.

Only Mike at SS can answer questions regarding availability of his products

Since it's a holiday w/e don't expect quick responses to any communication.

[JoeyG]

Thomas, if there is no performance difference between the two, is there any other difference that I may not be understanding?(much of this is new for me).

Just curious why they would offer two different ohm versions of the same sub that perform the same...my guess is to maybe match ohms with the rest of your system?...

Thanks for the help!

[RandyMidd]

SoundSplinter says RL-p15 D2 is out of stock and there is no phone number so I filled out the online form.

In case you don't get an email from Mike...he mentioned he was taking some time off ...I must have purchased the last two RLp15 s on hand.

[RandyMidd]

Thomas, if there is no performance difference between the two, is there any other difference that I may not be understanding?(much of this is new for me).

Just curious why they would offer two different ohm versions of the same sub that perform the same...my guess is to maybe match ohms with the rest of your system?...

I'm not Thomas...in fact you should make sure any advise from me is verified from someone with more experience!

While the T/S specs between the drivers are slightly different and so they will model slightly different...I think the driver offerings has more to do with what kind of load do you want your amp to see.

Check your amp specs and you'll see you get more wattage available with a 4 ohm load that you do with an 8.

You get even more with a 2 ohm load but it may be easier to exceed the limits of your amp with this arraingement.

I think you'll find that people will recommend to you the dual 2 ohm driver wired in series for a 4 ohm load.

You don't need to "match" ohms to your existing speakers...that's irrelavent AFAIK.

Good luck! :T

[JoeyG]

Thanks Randy,

These are the amp specs:
Carvin HD900 Power Amp: "900W bridged 4 ohms • Continuous RMS per CH: 8 ohms 200w, 4 ohms 300w, 2 ohms 450w. • Not rated "pulse power" or at 2 ohms for a few minutes like some amps"

When you say series, you mean multiple speakers right? I'm only running one 15...

Looks like I may have to spring for the D4 since no more D2's. Did he mention how long this 'time-off' would be? If I order online, do you think there would there be someone else there to ship the D4?

[RandyMidd]

When you say series, you mean multiple speakers right? I'm only running one 15...

No...I know you're only using one driver...but that one driver will have four connecting posts because it has two voice seperate voice coils... they need to be connected to your amp.

If you get a dual 2 ohm driver and wire them (the voice coils) in series it will make a 4 ohm load for your amp...then your amp can supply up to 900W to your driver.

Series means connecting the wires like a choo-choo train...with the caboose and the locomotive being the power supply from your amp and the cars being your voice coils.

If you get a Dual 4 ohm you'll have an 8 ohm load or possibly a 4 ohm load for each channel (not sure if that's a good idea - but it's possible) and your amp will supply less watts.

Now that I think about it ... I got the same page that you probably got saying it's (the D2) temporarily out of stock...but he was able to ship right away...so either the website isn't current or he can have them drop shipped...not sure but don't despair...I'd wait...you have lots to do in the meantime...the dimensions are on the website too.

Did he mention how long this 'time-off' would be?

Not exactly, but about a week from...???

[JoeyG]

Ah Ok, I see, I only had experience with basic Kicker speakers I guess, where there are only two posts (+/-)...

I am going up to Oregon mid July and my cousin does professional woodwork and has his own shop so I want to get the caps done while there. I have been sketching out and making notes of all the details so I think I have a decent idea of whats going on...

Thanks for the schooling...

[steve nn]

Since it's a holiday w/e don't expect quick responses to any communication.

I received a mail from Mike last Wednesday that he'll be going on a trip to a family wedding along with other family activities up here in Oregon and wont be due back until the 10th. It sounds like he is on vacation along with trying to coordinate it all with moving, to touch upon it lightly.

[RandyMidd]

I am going up to Oregon mid July and my cousin does professional woodwork and has his own shop so I want to get the caps done while there.

You may want to get your sonotube in your posession before your trip so you can take some first hand measurements and make your end caps to fit snugly inside...I wouldn't have a problem myself using the published driver measurements and no driver on hand for doing the woodwork.

For a pro-audio amp in this size range I like the J1400 mainly because of it's price/performance ratio and I think they look good (as pro-amps go) too. The downside is like Steve pointed out with the EP...fan noise. It has two variable speed fans that aren't IMO objectionable if you have it behind glass or listening at moderate volumes...otherwise it's less than ideal but tolerable (but not for some)...many replace the fans with quiet computer cooling fans and enjoy near blissful silence. You'll have to pay sales tax (when ordering from CA) and shipping but even then it may be less $ than a EP1500 or the Carvin....just another of the many options available to you as a DIYer.

[JoeyG]

My plan was to buy the correct amount of Sonotube, then buy an extra foot from the same roll so I could just take a foot of sonotube with me on my trip to fit the caps.

...but I also want to make sure I can get the desired driver (RL-p15 D2) before I start sizing up the actual length/dimensions of the Sono. (referring to stevecallas's earlier post in this thread)

Thanks again, I'll keep that amp in mind and on my list of components needed...

[JoeyG]

As Steve mentioned above, there should be ~260 effective liters after calculating the volume of the port and caps, but what about the volume of the speaker itself, does that have to be factored in as well? or is that supposed to be considered part of the 260 liters?

[ThomasW]

The computer programs generate a tuning based on a 'net' internal volume. One must build from a gross volume that takes into account everything that occupies space inside the tube. This means your tube is going to be bigger than 260L after you account for everything taking up space inside the tube.

[RandyMidd]

The space the RLp15 displaces in your enclosure is posted on the SS website...you can start making sawdust when you're ready!

[JoeyG]

Randy,
Trust me, I can't wait...A company here in town has the Sonotube, so I should be widdling a masterpiece soon hehe...

Sorry for all the questions, which may be common knowledge to you guys, but are you also factoring in the space the R30 might take up?
I was figuring I would calculate the speaker, cap and port volume...and add 260 liters on top of that calculation...

Thanks again!

[RandyMidd]

Insulation in larger quantities (than you'll be using) would add to your enclosure size...since your going vented, you'll just be lining the walls only and I think it won't change the inside volume one bit...double check this with someone else or check another sonosub thread.

As far as the driver goes, I got mine yesterday and looking at it has caused me to rethink how I'm going to mount it...so I thought I'd let you know. I may see what the board thinks about flush mounting it to the back side of the baffle (on a downfiring sonosub ). IMO the driver has mounting issues in its current form.

You can see from the pics that screw holes are typically obstructed by surround material. I'm loath to cut away surround material from screw holes or torque down the screws and have their heads embed in the surround material. As for the rubber mounting gasket...I could be wrong but it strikes me as worthless.

[ThomasW]

I may see what the board thinks about flush mounting it to the back side of the baffle (on a downfiring sonosub ).

Probably not the best idea given the elevated metal lip at the outer edge of the frame.

You can see from the pics that screw holes are typically obstructed by surround material. I'm loath to cut away surround material from screw holes or torque down the screws and have their heads embed in the surround material.

Hasn't been a problem for anyone I know, and there are hundreds of drivers using this construction in operation. Depending on whether it's foam or rubber, I take a soldering iron with an old tip and use it to enlarge the hole in the surround, or simply trim it with an Exacto knife.

[SteveCallas]

You can see from the pics that screw holes are typically obstructed by surround material. I'm loath to cut away surround material from screw holes or torque down the screws and have their heads embed in the surround material. As for the rubber mounting gasket...I could be wrong but it strikes me as worthless.

The rubber mouting gasket essentially solves your problem, doesn't it? It has some give and will compress against the metal frame of the driver pretty evenly - and you shouldn't be able to embed screws in it. I used bolts (1/4" diameter) as opposed to screws though.

[RandyMidd]

Probably not the best idea given the elevated metal lip at the outer edge of the frame.

:huh: That lip (the drivers cast frame outside of the surround) would be what contacts the MDF baffle if I were to install it this way (downfiring and inside the baffle instead of outside/flushmount).
I'd have gravity working for me.

What trouble do you see doing this?

Is there a penalty sonicly speaking having 3 or more inches of mdf (baffling material) around the driver cone for a sub?

Thanks!

[ThomasW]

What trouble do you see doing this?

Unless you machine a groove specifically designed to receive that lip, you'll crack the frame when you go to tighten down the mounting screws.

[Dennis H]

What trouble do you see doing this?

The problem is the end caps are usually glued into the tube. So, if you mount the driver on top of the bottom cap, there will be no way to remove it. That's a Bad Thing for a number of reasons -- problem with the driver, wiring problem, want to adjust the stuffing, etc.

[RandyMidd]

Hasn't been a problem for anyone I know...enlarge the hole in the surround, or simply trim it with an Exacto knife.

This will leave only 2mm of surround material on the front of the driver to maintain the seal to the cast frame...for comparison I looked at a 4" midrange driver on hand and I see it has more than twice that - sweet mounting design too! (picture 1)

I'm concerned that the screw head, which will be partly on the surround material and partly off, now has the possibility of mushing into the remaining 2mm of surround and damaging it. (picture 2 shows RLp)

The rubber mouting gasket essentially solves your problem, doesn't it? It has some give and will compress against the metal frame of the driver pretty evenly - and you shouldn't be able to embed screws in it. I used bolts (1/4" diameter) as opposed to screws though.

As I see it the gasket has only two purposes...on the front side it is cosmetic only...on the backside it can serve as a sealing gasket.

The holes on the face of the gasket are much bigger than the holes in the backside of the gasket and the driver frame ....so much so that they will swallow up a typical #10 screwhead...(see picture 3 & 4)...and sort of hide them but they still end up securing the driver the same way as described above.

IMO (I'm pretty sure about this) the gasket wasn't meant to be used as a gasket on the front side for your fasteners.

If you used 1/4" bolts then I guess you (slightly) drilled open the holes on the driver frame?

The problem is the end caps are usually glued into the tube. So, if you mount the driver on top of the bottom cap, there will be no way to remove it...

Thanks Dennis...sometimes the obvious isn't so obvious...this didn't even occur to me 'til I was sitting in traffic mulling things over. :lol:
I'd make one of the ends removable for access.

Unless you machine a groove specifically designed to receive that lip, you'll crack the frame when you go to tighten down the mounting screws.

Or I can mitigate the weight it sees by using a gasket material between the surround and that lip...(picture 2) I realize you probably aren't staring at one of these drivers right now and are going from memory...the frame material is pretty thick...even in this area...assuming the metal is decent quality, I think it'll be fine.

Is there a sonic penalty for back mounting and having 1 1/2 or more inces of MDF in front of the driver?

[seattle_ice]

Is there a sonic penalty for back mounting and having 1 1/2 or more inces of MDF in front of the driver?

You see that type of mounting all the time in IB configurations. I believe that the long wavelengths are relatively unnaffected by it.

[SteveCallas]

If you used 1/4" bolts then I guess you (slightly) drilled open the holes on the driver frame?

Correct. And the heads of the bolts are so big that they act like washers against the top of the rubber gasket. I used the thicker bolts (and extra baffle material) because the thought of a discontinued 45lb driver suspended upside down was a bit scary

[RandyMidd]

Joey,

I didn't mean to highjack your thread but I felt you may want to know about any potential problems with mounting this driver... seeing how you'll be cutting in advance of receiving it.

For me...I'm leaning towards sticking a gasket on the front of this thing and laying it upside down on some MDF and holding it in place with clamps...possibly these heavy 1/2" EMT (thinwall electrical conduit) straps. This'll be a bit more work than thought I'd have to do but aren't all projects?

[JoeyG]

Noway! I appreciate your posts, I am reading these posts and trying to absorb everything I can before I start working on this project. Looks like I will be up at 7am Monday ready to place my RL-p15 D2 order... Hopefully I will recieve it before Thursday so I can bring it with me on my trip and get the caps cut...

[ThomasW]

I realize you probably aren't staring at one of these drivers right now and are going from memory...the frame material is pretty thick...even in this area...assuming the metal is decent quality, I think it'll be fine.

Doh! Silly me.....

Yep I'm clueless regarding drivers built using the 'Venezuela' cast frame. There are only 3 mounted in subs in the house, and 4 mounted in the Arvo dipoles I'm listening to as I type this. In addition there's one raw driver sitting on the workbench, and 5 more in their shipping boxes in the basement.

So no I don't have any idea as to the proper way to mount them.... :roll:

[Dennis H]

I'd make one of the ends removable for access.

Sorry if I'm dense, but why are you going to all that trouble? The cardboard of a sonotube is a weak material so any removable (non-glued) end-cap joint is going to be weak. There are umpteen zillion successful sonsosubs built with the driver on the bottom so why do you feel the need to reinvent a wheel that probably won't work as well as the original round one?

[RandyMidd]

Sorry if I'm dense, but why are you going to all that trouble?

Dennis, if anyone's dense around here it's likely me!

I raised the subject of an alternate mounting method for my RLp drivers because I noticed the surround material on both is partly obstructed the screw holes. (pic_2) To mount the drivers using the screw holes I need to cut away surround material...when I'm done cutting there will be about 2mm of surround material left to provide a seal between the backside of the driver and the front. At this point my concern was that I'd be compromising the seal by cutting it away.

Now I'll have an uneven surface for the screw head. It (the head) will contact the surround material first which is roughly 1/8" thick...I anticipate that the screw head will mush into this material when tightened...possibly damaging it and further weakening the seal.

Alternatively, if I cut away enough surround material so the (standard sized) screw head can contact the frame fully I will have virtually no seal at that area and would be inviting air pressure to open it up more.

My drivers have a date on them of 6-06 so I assume they were made last month...others here that are using this driver made on a different date may not have issues to the degree I'm seeing. The problem could have been minimized with careful placement of the surround material to the driver frame during assembly.

The cardboard of a sonotube is a weak material so any removable (non-glued) end-cap joint is going to be weak.

I sincerely do appreciate this sort of input because I want to avoid trouble and be happy with the end result. :T
I'm going to cut an extra MDF "donut" similar to the driver baffle and glue it inside the sonotube near the top...I'll attach it to the bottom baffle with stringers glued to the tube (in)sides, I'll use gasket material on the top side of the donut and mechanically fasten the top cap to it. This works for me because my sub is so short.

There are umpteen zillion successful sonsosubs built with the driver on the bottom so why do you feel the need to reinvent a wheel that probably won't work as well as the original round one?

I know you're just trying to save me from myself and I completely appreciate that...but given the circumstances particular to these drivers what would you do? (not sarcasim - sincere!)

I would love to have just done this conventionally!

[ThomasW]

Or I can mitigate the weight it sees by using a gasket material between the surround and that lip...(picture 2)

Not an effective solution. Why? Over time the foam will collapse from the weight of the driver. At that point you'll have the driver weight sitting only on the raised outer lip of the frame. Putting adequate clamping pressure inside that lip to create an air seal in a small sealed sub will crack the frame. I've seen this happen.

The only way to effectively support the driver as you propose is to 1) route a groove that the lip can sit in, 2) instead of foam fabricate a ring from a non-compressible material that floats the driver higher than the raised lip of the frame.

Or.........

You could mount the driver in the normal way, and use the cast alu clamps designed for quick release in pro-sound woofer applications. These are designed to grab the raised outer lip on a cast frame driver, when it's front mounted

[Dennis H]

Ah, thanks for the pic, Randy. I see the problem now. Those clamps Thomas linked look like the hot ticket. That's what I'd do.

[SteveCallas]

I know you're just trying to save me from myself and I completely appreciate that...but given the circumstances particular to these drivers what would you do? (not sarcasim - sincere!)

I don't quite understand the problem either - is it that you feel the holes in the metal frame are too close to the driver's surround?

[RandyMidd]

...is it that you feel the holes in the metal frame are too close to the driver's surround?

For my drivers...unfortunatley, yes...but that may not be the case for yours it depends on how careful your assembler was with placement and glueing the flat part of the surround to the frame.

You could mount the driver in the normal way, and use the cast alu clamps

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