"Totally Tubular" Variation/Questions

[Frasier]

Mike, I don't know how to find your username, but this post is for you and anyone else who's interested. I like your design, and I just may endeavor to build it, with some modifications, as my first speaker project (EDIT: first advanced speaker project). So I hoped to bounce my ideas off you and/or the forum.

Firstly, based on your description, I thought of using them as studio monitors, paired with a sub for low-end extension. Is there any reason I'm missing that they would not be suitable for this role?

Now for mods: My first thought was that diffraction could be reduced by shrinking and/or rounding off the middle tube. The former would also allow the drivers to be closer together, and along those lines I wondered, "Why not put the tubes right against each other and just do the bracing differently?" I thought of perhaps wrapping the whole thing in fiberglass, or using some mold-able material, to fill in the gaps somewhat and make it more of a unified, contoured figure. Lastly, I was wondering if a somewhat higher-end driver such as the RS180-8 would yield any improvement (with enclosure volume adjusted as necessary) or if the specs are just too different for it to work (I also think black on black would be cool if I made the cabinets match).

Any advice?

[Paul Carmody]

Re: "Totally Tubular" Variation/Questions

This thread would work better in the main forum. However, I'll chime in here anyway. I've heard the Tubulars; they rock. I liked them so much that I had to do my own "tubular"-ish project: Tubifex.

[Frasier]

Re: "Totally Tubular" Variation/Questions

This thread would work better in the main forum. However, I'll chime in here anyway. I've heard the Tubulars; they rock. I liked them so much that I had to do my own "tubular"-ish project: Tubifex.

Thanks for the response! Your page will definitely be helpful, especially the construction tips. However, from your graphs it looks like your F3 is in the mid 100s, not 40 Hz? Also, how would you describe the difference in sound between yours and the Tubulars?

[[email protected]]

Re: "Totally Tubular" Variation/Questions

Hey Frasier! As you are probably expecting, any changes made to this (and any) speaker design would require a complete crossover redesign... especially if different drivers are used. This requires building the cabinet, loading the drivers, measuring the driver responses (at the location where you intend to use them due to the reflections caused by placing these on a desk... or wherever you intend to use them). This design was to be used on speaker stands, be maximally flat while non-fatiguing at high volumes (thus the dip from 2500 to 5000 Hz, which followed the Fletcher-Munson curve for hearing sensitivity) and be capable of handling large amounts of power...

I think if I were to use these as studio monitors, I'd first shrink the cabinet as you had stated, and maybe consider using a compression driver (such as the D220Ti-16) to enable an even lower crossover point... that's all hypothetical though. Just trying to throw some other ideas at cha.

[Frasier]

Re: "Totally Tubular" Variation/Questions

This design was to be used on speaker stands, be maximally flat while non-fatiguing at high volumes (thus the dip from 2500 to 5000 Hz, which followed the Fletcher-Munson curve for hearing sensitivity) and be capable of handling large amounts of power...

I think if I were to use these as studio monitors, I'd first shrink the cabinet as you had stated, and maybe consider using a compression driver (such as the D220Ti-16) to enable an even lower crossover point... that's all hypothetical though. Just trying to throw some other ideas at cha.

Yes I will have to learn some crossover design
Overall your description sounds like just what I'd want. I will be turning an empty ~10.5x12x8' room into my studio--kinda small, but the layout can largely be designed around the speakers, and I may hang them from the ceiling depending on how everything works out.

That driver's recommended crossover point is 2kHz... is there another reason a compression driver would be preferable for monitors? And any thoughts on upgrading the woofer, or would you stick with the DA175-8?

Thanks!

[[email protected]]

Re: "Totally Tubular" Variation/Questions

When you say, "That driver's recommended crossover point is 2kHz..." you have to understand that this is to give people a general idea on its use in Pro Audio environment (read high power). In a studio, this driver would receive far less power and could be crossed a lot lower... just saying that it was something I was thinking about doing in the future.

As far as the woofers, I really REALLY like the DA series of woofers. You could change these, but you'll have to start pretty much from scratch.

[Frasier]

Re: "Totally Tubular" Variation/Questions

When you say, "That driver's recommended crossover point is 2kHz..." you have to understand that this is to give people a general idea on its use in Pro Audio environment (read high power). In a studio, this driver would receive far less power and could be crossed a lot lower... just saying that it was something I was thinking about doing in the future.

As far as the woofers, I really REALLY like the DA series of woofers. You could change these, but you'll have to start pretty much from scratch.

Ah yes... going back through the specs I realize that despite having a similar power rating, the compression driver is a lot more sensitive. Does that make it more complicated to cross over? And after some research into horns, it occurs to me that my biggest uncertainty at the moment in terms of goals for the design is how big of a sweet spot I want--as it seems only a narrow-dispersion horn would fit there and go low enough.

I guess I'll stick with the DAs, then! Not really worth starting from scratch just to have black woofers.

[[email protected]]

Re: "Totally Tubular" Variation/Questions

Give me a few weeks (school is about to start up again) to work something up... Gathering some ideas to redo this design with different goals using different drivers. You could use the RS drivers, which are technically better than the DA series; I was just saying that any change would require starting from scratch. That may not be a bad thing... it's all about doing what you like with DIY audio! There are design principals to follow though.

I'll post a start to finish thread (heck, maybe even do a start to finish video) with what I come up with. There are many other tutorials in The Speaker Building Bible thread, in the mean time, to get you going if you want to try this on your own.

[Frasier]

Re: "Totally Tubular" Variation/Questions

Give me a few weeks (school is about to start up again) to work something up... Gathering some ideas to redo this design with different goals using different drivers. You could use the RS drivers, which are technically better than the DA series; I was just saying that any change would require starting from scratch. That may not be a bad thing... it's all about doing what you like with DIY audio! There are design principals to follow though.

I'll post a start to finish thread (heck, maybe even do a start to finish video) with what I come up with. There are many other tutorials in The Speaker Building Bible thread, in the mean time, to get you going if you want to try this on your own.

Wow, that's more than I could have hoped for! This is getting pretty exciting, and I'm liking the idea of the RS drivers (might even try the 4-ohms in my car later on). I'm in no rush, though--still a lot of work to do preparing the studio, and other projects (like the car).

[marlboro]

Re: "Totally Tubular" Variation/Questions

Check out my line array. Each of the 34 mid range speakers is in its own tube separated by 1/2 aire space from all of the others. There is some real benefit so that none of the backwash sound mixes with the other speakers and then muddies the direct sound by bouncing around and going through the front of the speaker in a delayed fashion.

[Frasier]

Re: "Totally Tubular" Variation/Questions

Check out my line array. Each of the 34 mid range speakers is in its own tube separated by 1/2 aire space from all of the others. There is some real benefit so that none of the backwash sound mixes with the other speakers and then muddies the direct sound by bouncing around and going through the front of the speaker in a delayed fashion.

Cool speakers. Do you mean the tubes are open on the back ends?

[marlboro]

Re: "Totally Tubular" Variation/Questions

Cool speakers. Do you mean the tubes are open on the back ends?

No each one is a seal design. The speakers were specifically designed to be using tubes that were 22.5 inches long. Tubes also eliminate 2nd order distortion inside the tube due to the characterisitics of sound propogation in tubes. They also were designed to have 4 lb per cu foot of fiberglass insulation wrapped in polyfill to keep the fibers from fouling the speaker magnets. This eliminates 98 % any sound returning to go out the front of the speakers coming from the inside, and increases clarity of the midrange dramatically. It forces the rear sound propogation to travel in a straight line toward the back of the speaker, but most of it is turned into heat and doesn't return, and since each speaker is carrying only 5% of the total sound load virtually nothing comes back. Best benefits of both sealed and unsealed.

[Frasier]

Re: "Totally Tubular" Variation/Questions

No each one is a seal design. The speakers were specifically designed to be using tubes that were 22.5 inches long. Tubes also eliminate 2nd order distortion inside the tube due to the characterisitics of sound propogation in tubes. They also were designed to have 4 lb per cu foot of fiberglass insulation wrapped in polyfill to keep the fibers from fouling the speaker magnets. This eliminates 98 % any sound returning to go out the front of the speakers coming from the inside, and increases clarity of the midrange dramatically. It forces the rear sound propogation to travel in a straight line toward the back of the speaker, but most of it is turned into heat and doesn't return, and since each speaker is carrying only 5% of the total sound load virtually nothing comes back. Best benefits of both sealed and unsealed.

Sounds great! I was just confused because you said "separated by 1/2 aire space" but now I get it. I was thinking you'd probably have stuffed them--it makes sense. Have you moved and upgraded it yet? Also wondering why you chose to space them out instead of having them as close as possible like the tweets.

[Frasier]

Re: "Totally Tubular" Variation/Questions

And what about the RS28F-4? It appears to be flatter over a greater range than the A... Is there a disadvantage? Or something like the Vifa XT25TG30-04?

[marlboro]

Re: "Totally Tubular" Variation/Questions

Sounds great! I was just confused because you said "separated by 1/2 aire space" but now I get it. I was thinking you'd probably have stuffed them--it makes sense. Have you moved and upgraded it yet? Also wondering why you chose to space them out instead of having them as close as possible like the tweets.

Well.... I haven't moved if you mean to Bar Harbor, Maine. I have to sell my house where I live, and this mean I have to finish renovating so I can put it on the market, but hopefully at this time next year all that will be done and I will be in Bar Harbor. Wanna buy my house? Its a great deal!

As to upgrading, that's pretty expensive. I would have to replace an entire tweeter or midrange line. Upgrading would mean finding a better dome tweeter that can have its flange cut so that comb filter distortion can stay above 15Khz or buying a group of very expensive ribbon tweeters. Or it would mean replacing 34 midrange 3 inch speakers. I would need to be assured that I was going to get a clearly noticable upgrade. And all of that is unlikely. The only possible upgrade would be to put in a floor to ceiling coupled woofer system by adding 4 12 inch woofers to it spaced about 18 inches apart. Or it might mean increasing the tweeter line to 48 tweeters per side, but since I'm presently putting in a full bathroom in my house(shower, new plumbing, electrical, flooring, ceiling, vanity, mirror and lighting) I really don't have time to worry about the speaker system.

I don't understand your comment about not having the mid ranges close to the tweeters. They are as close as is physically possible. And the mid ranges are as close to each other as physically possible with tube shaped cabinets and the need for an actual air space between the tubes.

Marlboro:o