Box Suggestion

Question for the smarter people out there. Looking at adding a sub-woofer to my 17 OR DblCab non-JBL. I designed 2 different options that will go behind the 60 portion of the the bench seat.

Red line shows a 6th order bandpass box using a JL Audio 6W3V3-4.
Green line is ported box using a Dayton Audio UM8-22

As you can see the 8" is a little louder but I feel like the 6" looks like it will hit lower. Not trying to win any SPL contests but we all know how these trucks need some more low end.

Let me know which way you would go!

 

What software are you using for your plot?

 

Speakerboxlite.com

I have WinISD at home but haven't put in all the T/S parameter for either speaker yet

 

From a personal preference, I'd pick lower over louder. Has a lot to do with your music choices though

 

That's what I'm thinking/prefer

 

Although I've never had the Dayton sub I have played on as many different boxes for that JL the V2 version. The best when I came up with was about .35 sealed that thing absolutely slams! For about 2 years I had it running off a KAC-5001 amp pretty much daily the entire time I was in my truck. It took that power and smiled right back never miss a Beat and still looks and sounds fantastic. Sorry I know you weren't asking for my biography with this sub but maybe it'll help you better decide which one to run between the two

 

Cone area is king!

Beyond that something doesn't add up using a seat of pants estimate. The Dayton claims SPL of 84.2 dB @ 2.83V which translates roughly to 80.7 dB at 1W/1m. The JL's sensitivity is a bit lower and power handling is half that of the Dayton's. I think we can call sensitivity a wash, but as the Ultimax will handle twice the power, it should be louder by roughly 3 dB. Considering that distortion also increases with cone excursion, I'd choose the Dayton. It isn't really fair to compare these plots either as one uses filters and one doesn't. Or is it the bandpass box shaping the response like that?

 

Both graphs are just using T/S parameters in the website. Doesn't account for any sound processing, just the enclosure. I THINK that's what you were referring to (No idea of your background so I apologize if you know a lot of this already). The YouTube video below explains 4th, 6th and even 8th order band-pass boxes pretty well.

https://www.youtube.com/watch?v=tKMEULLaYes
https://www.youtube.com/watch?v=kwa5EwwpZrQ

I've been playing around with some other drivers and I was surprised when I threw the Kicker CWRT672 in the program. Looks like this speaker was designed for 6th order BP enclosures and makes the response extremely flat, louder and with a bigger bandwidth than the JL (For a lot cheaper too )

Here's a similar enclosure the the one above but with the Kicker:




I'll add the 3D rendering of the box as well:






The biggest issue I see is using 1" ports. I think they might be a little loud with the air flow.
Maybe this weekend I'll try putting this stuff into WinISD and see what it says there


Thank you for your input though!

 

Yeah, I'd expect noise out of 1 inch ports too unless power is really low.

Never actually bothered modeling one. I built a bandpass enclosure some time ago - before computer modeling software. Not sure if I did it wrong, but I hated it. Output was anemic and it sounded like garbage. And it was really tough to build. Looks like a fun project though...subbed up!

 

So I was happy with a design and started laying out the cut sheets and that's when I realized that a 6.5" driver is still too big to be placed perpendicular to the rear seats. Even using 1/2" sheets of wood there simply wasn't enough space.

So instead of trying to build a 6th order band-pass I'm thinking I'm going to try my hand at a 6th order "bass-reflex" design.
Basically, still using a 6.5" driver (Dayton Audio DCS165-4), I'm going to have a large vented enclosure but instead of having the vent directly into the cab, it's going to be vented into a smaller enclosure which will be vented at a different frequency.

Playing around with Sketch-up it looks like there will be plenty of room using the entire back wall.

Problem is I don't know how accurate my output graphs (WinISD, Bass Box 6 and Speakerboxlite.com) will be since they do not include this type of design. I tried reaching out to Pete Kuliki about the software he uses but he gave me a pretty vague answer (not really surprising but still a little disappointing).

Hopefully this will work out and will keep this updated on what I find out.