Cyburg's Needle for Bass

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Relax

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Joined 2005
#1
I am looking to build a small enclosure similar, or exactly like, the Cyburg needle. I want the same tall skinny not-so-deep box witha single driver in it. I want to build two for musical bass.

What are your thoughts, suggestions?

I want to use them to compliment the sealed TB W3-871 lower end. Hopefully with the .10 cubic foot sealed enclosure on tope, resulting in a two driver facing me arrangement with healthy bass down to 40 hz or so for music.

Maybe just a good cheap woofer in the cyburg needle?

I am looking to spend around 20 for woofers. and mayeb another 20 for XO.

Is this realistic?

I noticed partsexpress is sellign Brauvox woofers for like 4 dollars, perhaps two in dipole arrangement int he needle?
 
#3
Do you have a link to a page with this Cyburg needle? Jim Read's page does not seem to be working, and when I go to the cached version the picutres aren't there.

This Cyburg needle is a pyramid, right? If not, what shape is it in?

I can model something for you using Martin J King's TQWT pages, but I unfamiliar with this Cyburg needle and need to make sure what you want.
 
#4
#5
No, i have the TangBand in the .10 cubic foot enclosure foudn easily all over the net.

I am really pleased with the sound and like it very much.

I want to build a TL for a different driver, cheap, to build then add the Tang Band ontop in the sealed enclosure. SO the hope is to get a decent looking and sounding floorstander using the TBs I already have.

I have tried the Tangband's in the Needle, which is the reason for my interest in maybe a modified needle for a different driver.

Any suggestions on a good little driver for bass in a Tl similarly sized?

I tried my best at working the Math Cad sheets, but I think I am impaired or the drivers i am using are not suited for TLs.

Are there any attractive yet cheap drivers to reienforce the low end of the TB W3-871s?

Thanks very much!
 
#6
Okay, best as I can see, the internal dimensions of the Cyburg is 36" high by 4" wide by 6.875" deep. One half inch building material is used except for the top and bottom, which is 0.75 " thick.

The internal volume-minus the diagonal divider-is 0.57 cu ft. Or 16 liters, as you prefer.

If nobody else does a sim, I think I can look at those two drivers you asked about tomorrow and see how they would fit into the Cyburg using Martin King's software.
 
#8
The Bravos have an Fs of 150 Hz. Don't think that is going to do it for you basswise.

You mentioned $20 for woofers. Is that each or for both woofers together?

I haven't modelled it yet, but here is a TangBand which looks like it might be dropped right into the Needle and give you something down into the 40's. About $20 per side. Want me to give that a try? http://www.partsexpress.com/pe/pshowdetl.cfm?&DID=7&Partnumber=264-824
 
#9
I was hoping to spend 20-30 tops for drivers, i kinda am just hoping to see if i can add something to fill these TB's lower end.

Plus I want the tall floorstander look with two drivers.

Would these work?

http://www.madisound.com/pdf/audax/VP130Z0.pdf

they are 14 a piece.

they daytons are 12.

SO to recap one of these 3 best price/performance:

http://www.madisound.com/pdf/audax/VP130Z0.pdf ----$14

http://www.partsexpress.com/pe/showdetl.cfm?&DID=7&Partnumber=290-302 -----$8

http://www.partsexpress.com/pe/showdetl.cfm?&DID=7&Partnumber=295-330 -----$13

I like the looks of the bottom two best(if their comes a tie...)

Thank you so much! Goodnight for me!
 
#10
First impressions, before modelling, is that the Audax and the Dayton look pretty good and should get you down into the mid 40's somewhere.

Will model them Saturday.

Now, one question. Do you have the Needle already built? You said you tried the TangBand in the Needle already. Reason I am asking is that with the 5.25" Audax and Dayton, the Needle might have to be widened slightly. My calculations show a Needle internal width of 4" and an external width, (with 1/2" building material) of 5".
 
#11
I would actually like to make the line overall width smaller than the larger driver. My plan is then to mount the driver in a large wooden cone, then cut out the top and bottom of the cone and mount this cone to the line and cut out the cross section.

It may be hard to picture, but just think of a cone with a TL running through it with all the necessary paths cut out. It will allow me to mount a driver larger than the TL in the TL and will look very pleasing in my eyes.

I already have 2 needles built, but they were prototypes and testers for the TB W3-871. I like them better in the sealed portion, but they lack bass. SO I would like to build and design a similar design of the needle for a larger or lower respons driver.

SO just similar dimensions is all I need, it doesn't have to be exactly that size, it could prolly be a little higher too if needed.
 
#12
Relax said:
I would actually like to make the line overall width smaller than the larger driver. My plan is then to mount the driver in a large wooden cone, then cut out the top and bottom of the cone and mount this cone to the line and cut out the cross section.
Click to expand...

Sounds to me like you plan a visually interesting version of a Daline, which is a nice way to build a Transmission Line. A Daline is a cavity which empites into a Transmission Line. Since the cavity takes up volume, the crosssection of the Line is reduced accordingly, and the bass output of a Daline is very similar to a Transmission Line only with reduced resonances.

I have modelled Dalines, but not Dalines with conical cavities. If the broad bottom of the cone is the part which empties into the Line, though, I think it will work. We shall see later today.

One question. If your lower woofer-say, the Audax-is going to be mounted in a pointy topped cone, how do you plan on mounting the sealed 0.10 cu ft TangBand?
 
#13
Is this, or something similar, what you are thinking about?
 

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#16
I am sorry, the stripe on the side is just an idea for finishing.

Yeah, its the TB in a sealed enclosure up top with the audax or dayton in the tl beneath it.

The Hope is to get the dayton to act as the bass driver and cover the lower frequencies, then XO to the TB for the mid and upper.

Is this a good idea at all?
 
#17
Relax said:
The Hope is to get the dayton to act as the bass driver and cover the lower frequencies, then XO to the TB for the mid and upper.

Is this a good idea at all?
Click to expand...

Of course it is a good idea. People have been making bass drivers that meet up with the midrange for a long time. It has only been fairly recently that the idea of a bass/mid became prominent. Before that, it was woofers from the bottom up to 500 or 800 Hz, mids from there up to 2,000 or 4,000 Hz, and tweeters above that. You are designing a conventional 3-way except the TangBand is the mid and tweeter at the same time.

I think I might have time to model this tonight-not certain. If not, early tomorrow. Now, I am assuming that the small enclosure holding the Audax or Dayton is very, very open to the TL once it gets inside the enclosure. The way you have it drawn, it almost looks like the Audax/Dayton has it's own small sealed enclosure. I am sure that is not what you want.
 
#18
I probably won't be able to help yoiu too much with the passive XO t the TangBand-you might want to start a new thread. Just curious-what is your XO point going to be, and do you plan to use the TangBand's enclosure as crossover element, saving the crossover components for the Audax/Dayton only?

From what I see, if you use a 0.1 cu ft enclosure, (2.8 L), you end up with a final Qtc of 0.75 and an F3 of 137 Hz.

Of course, you can cross over higher if you wish, at 300 Hz, 500Hz or so. It's up to you. but if you do that, you will need to add components for the TangBand as well as the Audax/Dayton.
 
#19
well, i will try the minimal route first, and corss the dayton off around 125 hz, and if it sounds good keep it that way.

If it sounds bad I will prolly xo higher than.

What kind of system should I set up to ensure the Daytons recieve enough wattage, but the TB aren't overpowered, they are 12 w rms where daytons are 40w.

I may have to XO both drivers in order to limit the power to the TB.

Thanks again for your help, its great having someone who actually knows there stuff.
 
#20
What kind of setup?

Well, drivers are routinely drivin by amps more powerful than their ratings-before recently it was hard to find a midrange rated for more than 40 W or so, yet they were used in systems rated for 150 watts or more.

Inthis case, the limiting factor is excursion. The TangBand has a linear excursion of 0.5 mm-one fiftieth of an inch! With it's cone area of 5 sq inches, it comes to a total linear air molving capability of 0.1 inch. That is very, very little.

You are going to use solid state amps for this project, correct? If you are, then I would think you would want to make the system capable of handling 20 Watts per channel. After all, that has pretty much been the minimum for solid state amps for decades.

The TangBand is rated as 87 dB efficient per Watt, so 20 Watts will drive it up to 100 dB-which is pretty loud.

If you review this chart from Small of Thiele-small fame, you see t hat it takes about 1.5 cubic inches of air moved from a sealed system to produce 100 dB SPL. 200 Hz requires one quarter of that, so 200 Hz would require 0.375. 280 Hz would require half that, which would be 0.180. However, if the speaker is going to be 6 dB down at the crossover point, that would 0.09 cu inches and the TangBand can do that.

So I would say that the lowest crossover for the TangBand to linearly reproduce up to 100 dB SPL would be 280 Hz.

Now, there MIGHT be a way to get the TangBand enclosure to be 3 or more dB down at 280 Hz without having to use a crossover component. It would require a smaller enclosoure than 0.1 cu ft, (2.83 L), and something called aperiodic loading. I would have to sim it in Martin King's software tomorrow. I don't know if aperiodic loading can achieve it, but Martin King's software should tell us one way or the other.

See you tomorrow.
 
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