Tham15 with kappalite 12LF

[slyslam]

Hi!

Short story: I built two tham 12 with some kapplite 12LF I had from dsimantled BFM T39. While being ok , I always tought there could be an improvement not because of the design which I think is amasing but mostly from what I heard from the experts ( specially JBells).Those drivers seem to like big cabinet

I did simulate the same speakers in the THAM15 and I got a revelation.
The simulation gives me similar output ( at 1 watt) as if you where using the original B&C 15". 100db @ 46.8dB, down to 98.4 " 75 and back to 100 @ 129.6hz

Two questions: 1-How do I post pictures of the hornresponse graphs?
2- Can any experts confirm my toughts? If so, what would be the best width for the cabinets?

I'm willing to give it a try and build one cabinet if it looks promising.

Thank in advance

Sylvain (Ze french dude from Montreal)

 

[Brian Steele]

1-How do I post pictures of the hornresponse graphs?

If you're using Windows 10, ALT-PRINT SCREEN will automatically save a copy of the open window to your OneDrive\Pictures\Snapshot folder. To post it to this forum, just click on the "Manage Attachments" button when creating your message - it should open a new page that allows you to select and upload images, which is what you can do for the image you just created.

2- Can any experts confirm my toughts? If so, what would be the best width for the cabinets?

I can confirm your findings. I've got a HornResp model of the THAM15 and I substituted the 8 ohm version of the Kappalite 12, and I'm seeing the same sim'd results.

 

[David McBean]

How do I post pictures of the hornresponse graphs?

See the post linked below:

http://www.diyaudio.com/forums/subwoofers/119854-hornresp-629.html#post4707300

 

[Zwiller]

If you're using Windows 10, ALT-PRINT SCREEN will automatically save a copy of the open window to your OneDrive\Pictures\Snapshot folder. To post it to this forum, just click on the "Manage Attachments" button when creating your message - it should open a new page that allows you to select and upload images, which is what you can do for the image you just created.




I can confirm your findings. I've got a HornResp model of the THAM15 and I substituted the 8 ohm version of the Kappalite 12, and I'm seeing the same sim'd results.

+1 same here but no cone volume data entered. While fooling I used 7000/860.50 from a 15 I think and although I lost a db at 50hz it brought low corner up to 96db @ 40hz... Me likey. Holding off sawdust until I find a <200l cab with 97db @ 40hz.

 

[Brian Steele]

+1 same here but no cone volume data entered. While fooling I used 7000/860.50 from a 15 I think and although I lost a db at 50hz it brought low corner up to 96db @ 40hz... Me likey. Holding off sawdust until I find a <200l cab with 97db @ 40hz.

You could try rejigging the sim in HornResp, then using my THAM spreadsheet to work out the folding of the horn. Getting it at or above 97dB in a sim in HornResp with a cabinet that small is likely going to be a challenge however. This is the best I could do so far, using an SS15-type fold. I'm not even sure if it can be folded up into a horn and still keep the same sim parameters, LOL.

 

[slyslam]

Here are the two output graph. Still try to figure out what makes such a huge difference between both. I suppose it's the lower BL.

One question: I built my tham with 15mm Baltic Birch. Do you think I could use the same thickness for the THAM 15 or should I stick with the original 18mm to avoid resonance?

tks
Sylvain

 

[Zwiller]

If you're comparing 4ohm with 8ohm I noticed that too, but not really sure why. I think the ply thickness aren't a huge concern as long as it properly braced but tend to look at 15mm as lighter duty/install and 18mm being a bit more road worthy.

 

[USRFobiwan]

in windows 7 and 10 press the 'windows' key and type in 'snip' it much easier then using printscreen.