B&C Sub designs

Re: B&C Sub designs

Kip,

http://www.bcspeakers.com/PRD/GRP/0000000356_3.jpg

Just as another alternative here is the stock design for TBW-100 from the B&C website. It has a bit larger port than the other design you had mentioned. I didn't look at the exact size of the design Alan came up with for you but I'm guessing this is a bit larger at 200 liters plus volume for the larger port and the driver. It has a lower F3 and Fb than what Alan designed which is goodi f you think you will like the extra extension. However I would bet that it will be excursion limited around 50 hz give or take a bit (they don't give the excursion limited power handling/output on the B&C website so I don't know for sure, but it is likely to be excursion limited in that 50hz range). Alan's design is unlikely to have that problem but gives up some extension so you can pick your trade off.

To use that design you can make the box essentially whatever shape you want as long as the baffle is large enough to accommodate the driver and the port, and the box is deep enough to accommodate the length of the port (31.7 cm in this case).

Have fun
 
Re: B&C Sub designs

So the B&C stock design is around 211 liters including port and net volume then just add the driver and bracing. Alan's design is around 192 liters so nearly 10% smaller.
 
Re: B&C Sub designs

I built that design around keeping the x max at 12mm or less from 40 hz up, sticking 3400 watts into it. I can make it go lower, but x max is exceeded, and power handling is very low at certain freq, like below 40 hz. The B+C design doesn't tell you the whole story. This is why I use double 18's, goes low as hell and can take all kinds of power.

I'll play with B+C design and see what the outcome is when I get a chance.
 
Re: B&C Sub designs

Loren- which stock design are you looking at? There's not a stock design specific for this driver, yet. It's still too new- but I would love compare the data from which one you are looking at....
 
Re: B&C Sub designs

Alan Sledzieski said:
I built that design around keeping the x max at 12mm or less from 40 hz up, sticking 3400 watts into it. I can make it go lower, but x max is exceeded, and power handling is very low at certain freq, like below 40 hz. The B+C design doesn't tell you the whole story. This is why I use double 18's, goes low as hell and can take all kinds of power.

I'll play with B+C design and see what the outcome is when I get a chance.
Click to expand...

How can you make a double 18 go lower than a single 18 without running into the same issues(assuming you use the same driver for both)?

Yes, the 2 drivers will make it louder, that's a given, but lower? Not unless it's a horn.

I personally like single 18's because they're easier for 1 person to move around and they scale up and down super easy.
 

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Re: B&C Sub designs

Evan Kirkendall said:
How can you make a double 18 go lower than a single 18 without running into the same issues(assuming you use the same driver for both)?

Yes, the 2 drivers will make it louder, that's a given, but lower? Not unless it's a horn.

I personally like single 18's because they're easier for 1 person to move around and they scale up and down super easy.
Click to expand...


Bigger cabinet volume, I'll play around with his drivers and see what happens. I use faital pro 18xl1500 an I got them pretty low and still handled full power at 35 hz, without exceeding excursion.
 
Re: B&C Sub designs

Kip Conner said:
Loren- which stock design are you looking at? There's not a stock design specific for this driver, yet. It's still too new- but I would love compare the data from which one you are looking at....
Click to expand...



It says 18tbw100 right on that sheet Kip. It gives the crucial dimensions, port are, length, box volume, you just build a box of your suited size to achieve this.
 
Re: B&C Sub designs

http://www.bcspeakers.com/PRD/GRP/0000000356_3.jpg

Its says a port area of 339.6 cm sq. Thats a 21 inch wide port by 6.36 tall, along with a 12.48 long port. There box is 200 liters, mine is 205 Litters.

Close enough on box volume.

I plugged the B+C port into the program, it came up with Fb 53 F3 40.4, What gives, I'm wrong or B+C has a misprint.

I got this,
3 =7.62cm
21= 53.34 cm

Using a 53.34 wide port yields 339.6 / 53.34 = 6.36 tall port on bc.
31.7 / 2.54 = 12.48 long port
 
Re: B&C Sub designs

Alan Sledzieski said:
Bigger cabinet volume, I'll play around with his drivers and see what happens. I use faital pro 18xl1500 an I got them pretty low and still handled full power at 35 hz, without exceeding excursion.
Click to expand...

But how do you get a bigger cabinet volume? 99.99% of dual 18's on the market are 2 smaller chambers. You gain the same thing putting 2 single 18's together.

PS- I'm also on board the big port train. Amazing what a larger port will do for you at high SPL.



Evan
 
Re: B&C Sub designs

Evan Kirkendall said:
But how do you get a bigger cabinet volume? 99.99% of dual 18's on the market are 2 smaller chambers. You gain the same thing putting 2 single 18's together.

PS- I'm also on board the big port train. Amazing what a larger port will do for you at high SPL.

, van
Click to expand...

I don't use 2 smaller cabinets, both 18's share the same box with 1 center port.

Not sure what is meant by the larger port train, bigger doesn't mean better, ya gotta plug the numbers and see what port the speakers want.
 
Re: B&C Sub designs

Alan Sledzieski said:
I don't use 2 smaller cabinets, both 18's share the same box with 1 center port.

Not sure what is meant by the larger port train, bigger doesn't mean better, ya gotta plug the numbers and see what port the speakers want.
Click to expand...

Smaller ports have a lot of disadvantages. They tend to choke off at high SPL- reducing what your box can do. You'll also get port chuffing, which sounds equally as bad at high SPL. When I design my boxes, I plug in the rated power, heat them up quite a bit and look at the air resistance at the port. A lot changes between a cold driver with 1 watt and a hot driver with 1200 watts.

My single 18's have a much much larger port then what you recommended- and what WinSD recommended, but it worked out very well with minor tweaking. My boxes are -4 @ 32.4hz and get quite loud!



Evan
 
Re: B&C Sub designs

Evan Kirkendall said:
But how do you get a bigger cabinet volume? 99.99% of dual 18's on the market are 2 smaller chambers. You gain the same thing putting 2 single 18's together.

PS- I'm also on board the big port train. Amazing what a larger port will do for you at high SPL.



Evan
Click to expand...

I never realized this, that the eaw 528 is two seperate inclosures, same with the jbl 728, Now I know why I don't like either box. Is the yorkville ls1004 two seperate inclosures?
 
Re: B&C Sub designs

Evan Kirkendall said:
Smaller ports have a lot of disadvantages. They tend to choke off at high SPL- reducing what your box can do. You'll also get port chuffing, which sounds equally as bad at high SPL. When I design my boxes, I plug in the rated power, heat them up quite a bit and look at the air resistance at the port. A lot changes between a cold driver with 1 watt and a hot driver with 1200 watts.

My single 18's have a much much larger port then what you recommended- and what WinSD recommended, but it worked out very well with minor tweaking. My boxes are -4 @ 32.4hz and get quite loud!



Evan
Click to expand...

1200 watts is not much on a single 18 though, so its possible your box's will over excursion with peak hits of double the continous power, I don't know, guess as long as we are happy with the design we built and it works for the individual.
 
Re: B&C Sub designs

Alan Sledzieski said:
1200 watts is not much on a single 18 though, so its possible your box's will over excursion with peak hits of double the continous power, I don't know, guess as long as we are happy with the design we built and it works for the individual.
Click to expand...

My drivers are 600wRMS. I chose efficient drivers over super power hungry drivers. They are well within their xmax throughout their whole power handling.



Evan
 
Re: B&C Sub designs

Evan Kirkendall said:
Every pro sub on the market is 2 chambers. Trying to make 2 18's work together in that large of a box is asking for trouble.


Evan
Click to expand...


Not at all, I have my Faital 18xl1500's in a single chamber box, double 18's, got a crest 8200 bridged on them, 4500w. No issues what so ever. Everyone loves them. Would not think of EVER buying a jbl, yakville or eaw double 18, they don't come close.

There is a port velocity chart that I watch when I'm building a box, I have no port noise
 
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