Help with 4th Order bandpass enclosure for a 15" 600W dual voice coil subwoofer (PA)

[col]

Hi, wondering if anyone can help with this:

I have this spare 15" 600W dual voice coil subwoofer (PA) that I want to try in a 4th order bandpass enclosure.

I had 3 of them in powered BR boxes that I got with faults, I was able to repair 2 of them, one of them was broken beyond repair though. I currently have the driver running passive in it's original BR box with the amp bit cut off.

What I would like to do is make a new 4th order bandpass cab so that I don't have to use it with electronic crossovers. A bit of EQ'ing will be fine.

I have run it through WinISD but it doesn't automatically pick a suitable bandpass enclosure and stuffing around doesn't seem to rectify it.

I have WT3 measured specs.

http://pix.minirig.org.au/main.php?g...c7b7a1d9e5b407


Here are some pics:

WT3

http://pix.minirig.org.au/main.php?g...serialNumber=1

photo from the back:

http://pix.minirig.org.au/main.php?g...serialNumber=2

WT3 impedance:

http://pix.minirig.org.au/main.php?g...serialNumber=2

WinISD estimated original BR enclosure:

http://pix.minirig.org.au/main.php?g...serialNumber=2

Any help would be much appreciated.

cheers,
col.

[col]

Looking at WinISD it might be better to go for a 6th Order Bandpass? More difficult to build though I guess.

http://pix.minirig.org.au/main.php?g...serialNumber=1

http://pix.minirig.org.au/main.php?g...serialNumber=1

col.

[Zero D]

Hi, I don't see a screenie for the 4th WinISD design, only BR + 6th ?

The 6th looks fine anyway

I havn't heard of those drivers before, do you have a link to their www ?

If you upload the WinISD .WPR file to somewhere like Free File Hosting Made Simple - MediaFire for eg. i will import it & see what i can do.

Regards

[djk]

Qts is too low for a BP4.

[col]

Hi ZeroD,

I don't think the driver is available on it's own. It's an OEM that came as part of the powered sub package. I have uploaded the WinISD project file here:

http://pix.minirig.org.au/main.php?g...c7b7a1d9e5b407

cheers,
col.

[col]

Originally Posted by djk

Qts is too low for a BP4.

Hi Djk, yeah I guess thats why WinISD didn't automatically come up with a box for it. The 6th order seems to work though. Iv'e heard that WinISD isn't particularly good at working out 6th order BP cabs though?

col.

[Zero D]

Hi, a few points i noticed.

BL = 43.75 NA Seems very high, but if correct i'm impressed !

No Xmax ? Did you omit it, or can't you get it ?

I inputted 4mm just to see, & i expect it should be at least that !

No Pe ? Did you omit it, or can't you get it ?

I inputted 200W just to see, but i "expect" it may take more ! And it appears to be back vented

See my screenie for my design with a 6th. Not massively different, but maybe more what you're looking for ?

Regards

[col]

Originally Posted by Zero D

Hi, a few points i noticed.

BL = 43.75 NA Seems very high, but if correct i'm impressed !

No Xmax ? Did you omit it, or can't you get it ?

I inputted 4mm just to see, & i expect it should be at least that !

No Pe ? Did you omit it, or can't you get it ?

I inputted 200W just to see, but i "expect" it may take more ! And it appears to be back vented

See my screenie for my design with a 6th. Not massively different, but maybe more what you're looking for ?

Regards

yeah that looks good. I have added some more parametres to the WPR and uploaded a updated version:

http://pix.minirig.org.au/main.php?g...14dc9af4bfaf87

The new version has pe and all the basket dimensions. I couldn't get xmax but by pushing on the basket I would say atleast 5mm. When I measured the driver using WT3 I wired the 2 voice coils together (series) and then in WinISD treated it as if it only had one voice coil. I'm assuming that is correct.

cheers,
col.

[Zero D]

yeah that looks good.

Thanks

I have added some more parametres to the WPR and uploaded a updated version:

It seems to be identical to me ?

The new version has pe and all the basket dimensions.

They would be in the WinISD .WDR file which you didn't upload.

I couldn't get xmax but by pushing on the basket I would say at least 5mm.

Not far off my estimate of 4mm.

When I measured the driver using WT3 I wired the 2 voice coils together (series) and then in WinISD treated it as if it only had one voice coil. I'm assuming that is correct.

You can wire them in Series, or Parallel.

Compared to a single VC driver SPL @ 1W, Parallel = + 3dB, Series = - 3dB

Series Voice Coils

Revc, BL and Levc = Double of one voice coil.

That's why we see BL = 43.75

Parallel Voice Coils

Revc, and Levc = Half of one voice coil. BL remains the same.

[col]

Originally Posted by col

Hi Djk, yeah I guess thats why WinISD didn't automatically come up with a box for it. The 6th order seems to work though. Iv'e heard that WinISD isn't particularly good at working out 6th order BP cabs though?

col.

I found this 6th order bandpass project where the author is using WinISD but not getting accurate results:

http://www.subwoofer-builder.com/bandpass/]

hmmm....