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Discussion Starter · #1 · (Edited)
I just finished building a DIY sub based on the Zaph Audio model. I must say I am impressed by the sub but it appears my room is too big for a 12" sub (18x25x10'). Another issue was the fact that the cherry veneer did not come out too good, it was blotchy which I don't understand (I used wood conditioner, my prior walnut veneered Polk came out fine).

I ordered a Dayton Audio RSS390HO-4 15" driver. I am planning to base the build on the "Drake" design except on a larger scale. I figured that an 18" cube with one inch sides will be about right (Later, I plan to buy another amp to rebuild the 12" sub to augment the 15" sub. I want to make both subs identical in size and looks, black gloss lacquer.).

I want to use the original 500-watt amp from the 12" Zaph build for the 15" sub. Is the amp strong enough for the 15" driver?
 

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Personally i think the driver needs a bigger cab to get the best from it and i think the amp will be ok. But in that size box it may struggle.
 

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Discussion Starter · #3 ·
from the TS parameters, the 18" driver will have a Qtc of 0.635, so I think it is large enough. Right now, it's the output that I have questions on...
 

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I can't find any model on the Zaph site that is a subwoofer.

http://www.zaphaudio.com/

What 12" driver is it, what is the net volume of the cabinet, and what 500 watt amp does it use?

As for the RSS390HO-4, a 18" cube built of one inch material will have a net volume of 2.1 cu.ft. Once I know what amp you have and the HPF it employs I can model it.
 

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Discussion Starter · #5 ·
Go to the archive section... It is 1/4 down the list... I attached a PDF of the web page below...

I attached my Bass Box Pro build sheet for the Zaph Audio subwoofer. It uses the Dayton Audio RSS315HF-4 and the Dayton Audio 500-watt sub amplifier. The Qtc is 0.620

I also attached my build sheet for the 15" RSS390HO-4 "Drake" plan. In a 18" cube and the amp isolated in a subchamber, the end Qtc is 0.615.

Thanks in advance...
 

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Discussion Starter · #7 ·
The Zaph build is 2.0 cubic feet net... The 15" Drake is 1.3 cubic feet net. The details are in the PDF files.
 

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Discussion Starter · #9 ·
hmmm.. Can you look at my build DA 15HO.PDF above and check the parameters? I reviewed it again and it all looks good to me at 0.615....
 

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Discussion Starter · #11 ·
I got a reply from HarrisTech, the makers of Bass Box Pro... It is an interesting read. It is good information for BBP users.

"BassBox 6 Pro attempts to provide a more complete "picture" of driver in a box. For example, classical formulas for closed-boxes do not consider the effects of acoustic absorption ("fill") inside the box. Some classic formulas are so simple that they do not allow the user to even specify the box leakage losses. BassBox 6 Pro includes this in its model.

If desired, you can "dumb down" BassBox Pro and cause it to produce similar results to other, more simple, programs. To do so, select the "Use Classical box calculations" option on the "Damping" tab of the Box Properties window. You can make this the default setting on the "Box" tab of the Preferences window (Edit > Preferences). You can even adjust the way BassBox Pro interprets the different Fill options on this tab.

However, we do not recommend that you make these changes. The reason we incorporated these features into our algorithms is because we believe they provide a more accurate box model. If you measure the Qtc of the box, it should be closer to 0.615 than 0.764 (assuming that your inputs are accurate). Why? Because the inclusion of acoustic absorption inside a box makes it "appear" larger than it really is and this reduces the apparent Qtc
."

After enabling classic calculations, the Qtc figures came out a lot closer to WinISD's models. It is something to consider for other modelers.
 
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