Please Check My Series 6th Design (BassBox6Pro)

[WalledSonic]

I’ve designed an isobaric 6^th order series tuned bandpass enclosure for my wife’s car.  I want to build a series 6^th for experience and for science. 

I have a firm grasp of the ins and outs of WinISD, but I am new to BB6.  So I started with measured values from my ported design with (4) 15’s, which I have dialed into WinISD and is pretty accurate.  Then I modeled the same box in BB6 to see the variation between the two programs and measured values.  That gives me a baseline ‘feel’ for BB6.

Can someone check my design?  I plan to test and modify the design to optimize the performance, and then I’d like to funnel that real data back into BB6 so I can really get a better feel for the 6^th order designs in BB6.

Here’s what I’ve come up with so far… This got me the most area under the curve but also a decent low end response:

[INSERT PIC HERE.  I COULDNT PLACE IT HERE WITH DIRECT UPLOAD]

Low port (for the design shown above) is 6”H x 3”W x 33.3”L, with 2 flared ends

High port (for the design shown above) is 8”H x 3”W x 8.4”L, with 2 flared ends

Goal was to keep port velocities under 30 m/s, cone excursion within limits, and boost the low end response without getting a severe dip between the two port tunings.  I really couldn’t bring the high tuned amplitude response down, maybe I need to widen the bandwidth?  Figured widening the bandwidth would cause an undesirable dip in the middle. 

***

Here’s the real measured TS parameters (via IM-SG) for the well-broken-in pair of Pioneer TS-W3003D4’s:

Dual voice coil, wired in PARALLEL (for measurements below) and both subs wired parallel to the amp.

Re (parallel, each sub) = 1.6ohm

Fs = 31.4 Hz

Vas = 2.822 cu ft

Qms = 3.706

Qes = 0.494

Qts = 0.436

Mms = 126.9 g

Cms = 0.203 mm/N

Dia = 10.2”

Sd = 81.7 sq in

Xmax = 14mm one way

I’d like to set the tuning for the low side at 31ish Hz and tuning on the high side at 63ish Hz.  The subsonic filter setting will be determined via testing after the box is built and tuned to its final state.

I have about 5 cubic feet total to play with for this isobaric series 6^th setup.  I can toy with the final XYZ dimensions, I’m mainly looking for a solid set of values for volumes and port areas & lengths (if the ones I calculated in BB6 are not suffice).  Rectangular ports are preferred but I can do aeroports or kerfed circular port if that’s a better route.  I am competent with woodwork.

I’ll be starting a build log for this box design and its installation.  Planning to include a lot of measured data (IM-SG and AMM-1).  Really stoked for this build.

Thank you in advance!

[Triticum Agricolam]

I'll plug your numbers into HornResp when I get in from the field. 

[77-AUDIO]

sounds like fun man.  I want want to build a 3 chamber 4th order for 4 8" or 4 10" subs.  

found a DC 3.5k new for 800.  Going to be putting some cash away for that and also have to pus some away for my daughters graduation from the ARMY

[Triticum Agricolam]

Here is what I got, this is on 1200 watts.
Frequency Response:

 

Cone Excursion:

 

Rear port velocity:

 

Front port velocity:

[WalledSonic]

12 minutes ago, Triticum Agricolam said:

Here is what I got, this is on 1200 watts.
Frequency Response:

 

Cone Excursion:

 

Rear port velocity:

 

Front port velocity:

Thanks for running the design Triticum.  It seems drastically different from the BB6 output.  Not sure where to go from here...  From your previous posts, it seems like Hornresp is really accurate.

Is the Hornresp cone excursion shown as a 2 way value?  BB6 uses one way.

It seem the port velocities are double what BB6 gave me too.  For the rear port, if I make it any larger than I will be getting close to the 3-4' range, which I've heard could incite port resonances.

If the outputs you gave are indeed created per the values I supplied above, would you be so kind to recommend a different set of values for volumes and ports?

Man, it sure does suck if BB6 is this far off.  I may just need to learn Hornresp.

[WalledSonic]

52 minutes ago, 77-AUDIO said:

sounds like fun man.  I want want to build a 3 chamber 4th order for 4 8" or 4 10" subs.  

found a DC 3.5k new for 800.  Going to be putting some cash away for that and also have to pus some away for my daughters graduation from the ARMY

Looking forward to seeing what you come up with man.

[77-AUDIO]

need to meet up so you can hear mine, i know its not like the sonic but still its bass.  

[Triticum Agricolam]

It is possible there is a difference in input power between our two simulations. I might be simulating a much higher power level than you are, which would explain the difference between the results. Or I may have just fat-fingered something. 

 

HornResp defines input power by voltage. I assumed both subs would be wired in parallel for a 1 ohm final load and thus 34.6 volts for 1200 watts.  I'm not familiar with BBP, how does it define input power?

[Keith77]

2 hours ago, 77-AUDIO said:

sounds like fun man.  I want want to build a 3 chamber 4th order for 4 8" or 4 10" subs.  

found a DC 3.5k new for 800.  Going to be putting some cash away for that and also have to pus some away for my daughters graduation from the ARMY

I know its not DC but ill sell you a Damn near new B2 zero1 for less than that LOL

[WalledSonic]

40 minutes ago, Triticum Agricolam said:

It is possible there is a difference in input power between our two simulations. I might be simulating a much higher power level than you are, which would explain the difference between the results. Or I may have just fat-fingered something. 

 

HornResp defines input power by voltage. I assumed both subs would be wired in parallel for a 1 ohm final load and thus 34.6 volts for 1200 watts.  I'm not familiar with BBP, how does it define input power?

Input power is entered per sub, along with the TS Parameters.  You can see the value "Pe" on the lefthand column of the screenshot i took.