Understand BassBox Pro

[hawkei67]

Hi all,
I have just got into designing and building speaker boxs for car audio. Currently I have a 1999 Ford Taurus 4-door, factory premium stereo/cassete that has the cd function but no cd changer so I use a cassete adapter that you can insert in the tape deck then plug the wire coming from it to an ipod/mp3 player/psp/whatever, I use a2 gb mp3 player for my use though. I have 2 amps in the trunk, 1 is an old pioneer 220 watt and the other is an acoustic lab 100 watt. The pioneer I use for 2 Radio Shack Pro Series 300 watt 8" subs in a regular sub box with the tweeters removed and those ports closed air tight so there are no vents at all, the other amp is being used to power the factory rear deck 5x7's. I listen to a lot of guccimane, bass outlaws, plies, ect... I love the rolling bass. A lot of black folks can't believe I got this system to sound so sweet and rolling with the bass with such old equipment. I have always like the sound of those q-logic bandpass box's that have a plexiglass face that fits in a single square hole in the front of the box and dual 4 inch O.D. 9 inch long round vents on the top of the box. A friend of mine who has built plenty of box's for his own low rider and show trucks and he put one together for my nephew using a 10" woofer placed between the 2 bucket seats somewhat behind them in a 2003 Ford Ranger Extend Cab with a Kenwood stereo and no amps and that thang hit harder and had such great bass and sound that I wanted to build one to go into the trunk of my Taurus right in the center of the trunk. My question is this, anyone have any good starting deminsions, projects I could use to begin with? Also, what is the cheapest but best 10" sub for my application using the power I mentioned. I would also like to know how to revert all bassbox pro settings and values default so as not to get numbers mixed up. Thank you in advance.

[hawkei67]

Here is my current settings, parameters and dimensions. Am I doing something wrong here? This setup is designed around an ES1056 driver by ESX Inc. but I would like to use a cheap in price but good in quality driver if someone could help a newbie out. Thank you in advance.

File: single 10 Inch bandpass cube w 2 vents at 4inch dia. and 9inch long.bb6
-----------------------------------------
Driver Properties
Name: ES1056
Type: Standard one-way driver
Company: ESX, Inc.
No. of Drivers = 1
Fs = 49.42 Hz
Qms = 12.84
Vas = 31.19 liters
Cms = 0.185 mm/N
Mms = 56.21 g
Rms = 1.359 kg/s
Xmax = 8 mm
Xmech = 12 mm
P-Dia = 209.6 mm
Sd = 345 sq.cm
P-Vd = 0.276 liters
Qes = 0.45
Re = 3.5 ohms
Z = 4 ohms
BL = 11.66 Tm
Pe = 100 watts
Qts = 0.434
no = 0.807 %
1-W SPL = 91.4 dB
2.83-V SPL = 94.81 dB
-----------------------------------------
Box Properties
Name:
Type: Bandpass Single-Tuned Box
Shape: Prism, Bandpass
with two chambers
Chamber 1 - lower-freq.
Vb = 0.46 cu.ft
Fb = 91.03 Hz
QL = 7
F3 = 53.46 Hz
Fill = none
Chamber 2 - upper-freq.
Vb = 0.351 cu.ft
Fb = 91.03 Hz
QL = 7
F3 = 155 Hz
Fill = none
No. of Vents = 2
Vent shape = round
Vent ends = one flush
Dv = 3.5 in
Lv = 15.12 in

[scameron78]

look into powerbass subs. had 2 M series 10s in a sealed box with seperate chambers, 1 cu ft each. sounded good for a low budget. when it comes to car audio you need to decide on SPL or HIFI. personally i'd ditch the bandpass and just build a good slot ported box. figure the cu ft for the driver. i have an excel file created by an individual on a car audio site that is extremely helpful in design and building the box. gives you all the dimension for the cu ft. lots of factors to think about when it comes to car audio. remember your sub will be in the truck vs your buddies being inside the cab.

[scameron78]

sorry by hifi i mean sound quality. i just always associated sound quality with hifi for some reason.

[Brian Steele]

Originally Posted by hawkei67

File: single 10 Inch bandpass cube w 2 vents at 4inch dia. and 9inch long.

The data you included refers to 3.5" vents that are 15.12" long. Might want to check that.

4th order bandpass boxes for cars can be a lot of fun (I've built a few). Just bear in mind they can be a great way of destroying speakers too. The car audio world seems to be more focused on slot-vented boxes these days however.

[hawkei67]

I have given up on the bandpass design and went instead to a sealed or ported design. I read 3 different articles somewhere else that vented or slotted is the way to go if I am looking for a nice bass feel (vibration) but yet requires no amp because the box would be designed for the frequency of the speaker. I think vented is my best bet but I am still gonna use my amp to drive it so I designed one like that and came up with some great results I think. Here is the new design dimensions, tell me what you think and any improvements that should be made. Is this really the way to go?

File: single 10 in vented slanted box excellent.bb6
-----------------------------------------
Driver Properties
Name: S1-104
Type: Standard one-way driver
Company: Rockford Fosgate Corp.
Comment: Series 1 S1
No. of Drivers = 1
Fs = 36 Hz
Qms = 3.75
Vas = 67.96 liters
Cms = 0.37 mm/N
Mms = 51 g
Rms = 3.186 kg/s
Xmax = 5.08 mm
Xmech = 7.62 mm
P-Dia = 214 mm
Sd = 359.6 sq.cm
P-Vd = 0.183 liters
Qes = 0.4
Re = 3.4 ohms
Le = 1.47 mH
Z = 4 ohms
BL = 10 Tm
Pe = 100 watts
Qts = 0.36
no = 0.764 %
1-W SPL = 91 dB
2.83-V SPL = 94.7 dB
-----------------------------------------
Box Properties
Name:
Type: Vented Box
Shape: Cube
Vb = 1.159 cu.ft
Fb = 37.98 Hz
QL = 6.931
F3 = 55.67 Hz
Fill = heavy
No. of Vents = 1
Vent shape = round
Vent ends = one flush
Dv = 3.31 in
Lv = 9.197 in

Any suggestions would be greatly appreciated. Just wanting a good roling bass with a good vibrating feel but yet clearly understood, I will still be using just one woofer and a pioneer 220 watt amplifier I will be running in bridged mode.

[hawkei67]

Let me get this straight. When designing a sub box, I am supposed to design the box to the resonant frequency of the sub (Fs). Once I select a driver or input my driver parameters then all I should need to do is adjust the shape of the box, damping and vent properties and not mess with any of the driver parameters being sure to keep the Fb-F3 around 35 to 50 hz, right? When checking the plot graphs for any box I design should stay around the impedance of the woofer (Z) right? New to this box building thing so kinda confused about things right now. I design amateur radio, cb, and hdtv antennas using the popular antenna modeling software called NEC4Win by Orion Microsystems and have designed some awesome beam (yagi) antennas, fractel antennas, ect... Been doing this for over 12 years and working on electronics for about 15 years (tv's, hdtv's, cb's, ham's, xbox's, xbox360's, ps2's, ps3's, psp's, dvd players and especially pc's and laptop's. A lot of people on amateur radio and cb have made a lot of requests for me to design them some, so you see, I am not an amateur when it comes to crunching numbers, just need a little assistance til I get the hang of it. Thank you all for the current replies to my thread and I look forward to hearing the design in action. Like I said earlier, I want a good clean bass vibration with great sound at the smallest cost and least amount of reuired power. The automobile it will be going in is a 1999 Ford Taurus 4-door, in the trunk using a pioneer 220 watt amp. I have read, read, read and read some more at this site, caraudiohelp, google search results, youtube how-to's for Bassbox Pro and the supplied manual and help files from BassBox Pro but still somewhat confused about what type of box needed for 1 driver at 10" in diameter using the least amount of power but yet sounds like a quality system and still have that heavy vibrating feel. Any and all help would be greatly appreciated and all suggestions are needed even the bad ones, lol. Thank you for all the advice and current replies.

[hawkei67]

I went ahead and tried one more thing on the bandpass I was attempting earlier and I think I came up with a pretty good box. Input these into your bassbox and let me know if you think it is worth building and testing out. This time I tried a vent diameter of 3.5 inche's and a vent length of 13 inches and the plots look pretty good unless I am doing something wrong.

File: MM2084 4ohm 8in bandpass test2.bb6
-----------------------------------------
Driver Properties
Name:
Type: Standard one-way driver
No. of Drivers = 1
Fs = 43 Hz
Qms = 15.13
Vas = 15.91 liters
Xmax = 18.01 mm
P-Dia = 203.2 mm
Sd = 224 sq.cm
Qes = 0.68
Le = 1.84 mH
Z = 4 ohms
Pe = 400 watts
-----------------------------------------
Box Properties
Name:
Type: Bandpass Single-Tuned Box
Shape: Prism, Bandpass
with two chambers
Chamber 1 - lower-freq.
Vb = 1.099 cu.ft
Fb = 52.86 Hz
QL = 6.992
F3 = 36.19 Hz
Fill = none
Chamber 2 - upper-freq.
Vb = 0.402 cu.ft
Fb = 59.8 Hz
QL = 7
F3 = 100.1 Hz
Fill = none
No. of Vents = 1
Vent shape = round
Vent ends = one flush
Dv = 3.5 in
Lv = 16 in

[revboden]

Let me get this straight. When designing a sub box, I am supposed to design the box to the resonant frequency of the sub (Fs).

not really. When you add the box you start to deal with the Fb. If you tune the Fb lower than the Fs the graph will roll off sooner but have more low end. if you tune the Fb higher than the Fs you will have a hump above Fs in the graphs and you'll get more output above Fs but less below Fs.

Once I select a driver or input my driver parameters then all I should need to do is adjust the shape of the box, damping and vent properties and not mess with any of the driver parameters being sure to keep the Fb-F3 around 35 to 50 hz, right?

Yes, adjust the size of the box and port length to tune the box. Or for a sealed box just adjust the size of the box. Watch the charts to see what each change does.

If you want SQ tune the box lower than you think necessary ~25hz or so, group delay goes way up around tuning, group delay above 30ms is audible as a slurring of the frequencies.

When checking the plot graphs for any box I design should stay around the impedance of the woofer (Z) right? ...

???

I want a good clean bass vibration with great sound at the smallest cost and least amount of reuired power... in the trunk using a pioneer 220 watt amp. ... but still somewhat confused about what type of box needed for 1 driver at 10" in diameter using the least amount of power but yet sounds like a quality system and still have that heavy vibrating feel.

Find a Driver with a SPL (1W/1m) that is high (~90db) and you'll need less power to drive it. A driver with a SPL of 87db(1W/1m) would need twice the power to output the same volume.

a ported box tuned low (20-25hz) will sound better (SQ) than one tuned higher (35-50hz) but the ported box tuned higher will have more output above the tuning frequency but much less below it... You decide what is more important. You can't have both but you can have something in-between (Fb 25-35hz).

[hawkei67]

Thank you for the prompt response an information, makes a little more sense now. What do you think of the vented box I posted earlier? Do the graphs look good to you? Should I improve on something in that design to get better vibration but good clean bass? I would post the graphs from Bassbox Pro but not sure how to do that thru bassbox. Should I stick with this vented design for my type of car and small amplifier and still get a good vibration? Once again thank you.