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Tuning freq ?

 

Bronze Member
Username: Shopvac

Post Number: 71
Registered: Jul-10
Hey guys I have a r/f p3d210 sub that would be running off T500-1 bdcp @ 1 ohm, I want to go ported, and would be building the box my self. my question is what would be a good tuning frequency for the box with respect to this sub? all help is appreciated.

I listen to a wide varity of music but mainly rap, hip hop and reagge/dance hall, and would like it to hit as low as possible, right now its in a seal box and it sounds too peaky.

My front stage is stock but will up grade later, heading towards an sq system overall.
 

Gold Member
Username: Sinful_systems70

15 INCH WANG...

Post Number: 1314
Registered: Nov-06
I would go somewhere in the 30-35 hz range for good lows. JMO
 

Gold Member
Username: Sinful_systems70

15 INCH WANG...

Post Number: 1315
Registered: Nov-06
Check out some pictures of the boxes I have built in the "Dual 18" enclosure FOR SALE FEELER" Thread. Maybe you can get some ideas. Please give opinions. Thanks.
 

Silver Member
Username: Joe1234

Post Number: 762
Registered: May-09
Ok RF suggest the following Vb=1.4 cuft Fb = 40Hz this produce the loudest setup, here are 2 suggestions:

Upload

Powerful and deep (yellow):
Vb=1.4 cuft Fb = 30Hz
SQ alignment (green):
Vb=1.8 cuft Fb = 22Hz

Since the subwoofer has relatively low sensitivity yellow will get you the best mix.
 

Bronze Member
Username: Shopvac

Post Number: 73
Registered: Jul-10
thanks alot guys, I really appreciate it.

Keep up the excellent work Joe, you are doing an outstanding job here, its a pleasure reading your posts !!!
 

Silver Member
Username: Joe1234

Post Number: 765
Registered: May-09
Ok Shopvac, here is a utility in case you intend build a slot ported box:

http://www.reaudio.com/box.php
 

Bronze Member
Username: Shopvac

Post Number: 77
Registered: Jul-10
Thanks Joe !
I have decided to go with the 1.4 cuft @ 30 hz which would give me a better mix as you suggested, is that 1.4 cuft after all displacement (woofer, port)?
 

Silver Member
Username: Makinblak

Monroe/Monticello, La/Ar

Post Number: 762
Registered: Oct-10
Joe's the guy to kno fasho, sprained ur elbo tryin to jump out the windo and here's the guy u know, with da endo and some blo an ur good to go , done passed out on the flo, hell jo run out the do!
 

Silver Member
Username: Joe1234

Post Number: 772
Registered: May-09
Vb is the net internal volume to that you need to add port displacement and driver displacement top mounted (usually).
 

Bronze Member
Username: Shopvac

Post Number: 78
Registered: Jul-10
Please disregard this empty post.
 

Bronze Member
Username: Shopvac

Post Number: 79
Registered: Jul-10
Top mounted meaning the actual way the woofer is mounted, meaning the normal way its screwed onto the front face of the box?
 

Silver Member
Username: Joe1234

Post Number: 774
Registered: May-09
Front mounted is a better way to say it, you understood correctly anyways, I have checked with some software and it should be 0.126 cuft using 0.75" MDF.

If you provide the external dimensions I could give you some feedback on your calculations like port airspeed, excursion plot etc..
 

Bronze Member
Username: Shopvac

Post Number: 80
Registered: Jul-10
Thanks Joe, as soon I get it figured out I will post the ext dimensions I came up with...
 

Silver Member
Username: Joe1234

Post Number: 782
Registered: May-09
Ok Shopvac, I would not advice to use the calculator above for a final design as I think I have discovered some flaws in it, specifically the port displacement is off and the cutlist dimensions also.
 

Bronze Member
Username: Shopvac

Post Number: 81
Registered: Jul-10
ok Joe, I am trying the torres box tuning calculator, will let you know what I come up with...
 

Bronze Member
Username: Shopvac

Post Number: 82
Registered: Jul-10
Ok here is what I come up with >>

Vb:1.4 cu ft
Fb: 30 hz
Vgross 1.834 cu ft

Box outside dimension (3/4" thick) >>
H: 12
W: 23.8125 (23 13/16)
D: 15

Port (L- Port) >>
H: 10.5
w: 1.5
L: 29.625 (29 5/8)

let me know what you think, any more info please let me know...
Thanks.
 

Bronze Member
Username: Shopvac

Post Number: 83
Registered: Jul-10
I really dont know how accurate torres calculator is, I use a combination of torres and r/f woofer box wizard.
 

Silver Member
Username: Joe1234

Post Number: 792
Registered: May-09
I think your box will do, no problem, The following is done by these guidelines:

http://mobile.jlaudio.com/support_pages.php?page_id=165

Proper end correction is considered, let's just hope that my code is clean of course, commercial soft I use do not support slots. The torres run improperly on my system so no way to test.

Vb:1.4 cu ft
Fb: 30 hz
Vgross 1.931 cu ft

Box outside dimension (3/4" thick) >>
H: 12
W: 26.924
D: 14

Port (L- Port) >>
H: 10.5
w: 1.5
L: 31.133
 

Bronze Member
Username: Shopvac

Post Number: 84
Registered: Jul-10
ok, I will recheck my calculations and proceed to build and test the enclosure and give feed back. Thank you for all your help, I really appreciate it.
 

Silver Member
Username: Joe1234

Post Number: 800
Registered: May-09
Ok Shopvac just to complement, with your data I am expecting that enclosure to tune above 30Hz something like 31-33Hz, you may want to check if the program is setup to add the end correction for slot ports, the dimensions I provided will tune lower.

The reason I am telling that I don't think there is a problem is that the frequency shift will not affect the general idea but if you want it to go lower look into it.
 

Bronze Member
Username: Shopvac

Post Number: 85
Registered: Jul-10
ok Joe, i will look into it.

I also decide to work on another box, with the same woofer with an areo port, 4'' diameter. will post up some dimensions as soon as I am fininish.
 

Bronze Member
Username: Shopvac

Post Number: 86
Registered: Jul-10
I have check and according to the writer of the program the end correction is factored in..
 

Silver Member
Username: Joe1234

Post Number: 846
Registered: May-09
Ok shopvac, so I noticed that the port is properly tuned, what was bothering the result was your gross internal volume, let me share my data on your box so at least I end up knowing where did I went wrong:

Upload

Here is the output of my code:

Wood Thickness = 0.75 in

External Box Height = 12 in
External Box Depth = 15 in

Fb = 30.0037002 Hz
Lve = 30.375 in
Vb = 2419.2 in^3, 1.4 ft^3

Port Center Line Length = 29.625 in

L Port Internal Assembly Parts:

Front to Bottom Length = 12 in (on Red)
Extension Length = 14.625 in (on Blue)

Port Width = 1.5 in
Port Height = 10.5 in
Port Length = 29.625 in
Port Airspace = 466.59375 in^3, 0.27001953 ft^3
Port Internal Assembly Parts Displacement = 209.671875 in^3, 0.12133789 ft^3

Driver Displacement = 217.728 in^3, 0.126 ft^3

Total Displacement = 893.993625 in^3, 0.51735742 ft^3
Gross Internal Volume = 3313.19362 in^3, 1.91735742 ft^3


Really is not going to make a real difference in the outcome but your gross internal is short according to this, review this info if you just care about getting it done right.
 

Bronze Member
Username: Shopvac

Post Number: 87
Registered: Jul-10
Ok Joe I will, thanks for your patience.
 

Bronze Member
Username: Shopvac

Post Number: 88
Registered: Jul-10
Something is not adding up right and I cant put my fingers on it as yet maybe I am doing something wrong, but I am trying.

one thing I have notice with the specs you have used, is the driver displacement which is 0.126 cu ft

According to the specs I have from r/f for this woofer (p2d210) which is a discontinued model is 0.074 cuft for woofer displacement ?


P3D210 10" Punch P3 2-Ohm DVC Subwoofer

Size 10"
Nominal Impedance Dual 2-Ohm
Power Handling 400 Watts RMS 800 Watts Max
Voice Coil Diameter 2.5" 4-Layer (6.35 cm)
Magnet Weight 78 oz. double stacked
Speaker Connector Dual 10 AWG compression
Fs (Hz) 27
Re (Ohms) 3.30
Le (mH) 3.2
Qms 6.70
Qes 0.52
Qts 0.50
Vas (Liters) 24.5
Sd (cm2) 310
SPL (dB @ 1w/1m) 83
Xmax (mm) 16.2
Woofer Displacement 0.074 cu. ft. (2.10 Liters)
Cutout Diameter 9.0 in. (22.86 cm)
Mounting Depth 6.25 in. (15.56 cm)
Shipping Weight 18.50 Lbs. (8.39 Kg.)

Also, whats the external box width?
 

Silver Member
Username: Joe1234

Post Number: 848
Registered: May-09
Ok I have recalculated for the P3D210 (not the P2! please note):

Wood Thickness = 0.75 in

External Box Height = 12 in
External Box Depth = 15 in

Fb = 30.0037002 Hz
Lve = 30.375 in
Vb = 2419.2 in^3, 1.4 ft^3

Port Center Line Length = 29.625 in

L Port Internal Assembly Parts:

Front to Bottom Length = 12 in
Extension Length = 14.625 in

Port Width = 1.5 in
Port Height = 10.5 in
Port Length = 29.625 in
Port Airspace = 466.59375 in^3, 0.27001953 ft^3
Port Internal Assembly Parts Displacement = 209.671875 in^3, 0.12133789 ft^3

Driver Displacement = 127.872 in^3, 0.074 ft^3

Total Displacement = 804.137625 in^3, 0.46535742 ft^3
Gross Internal Volume = 3223.33762 in^3, 1.86535742 ft^3

External Width = 24.2395952 in
External Height = 12.0 in
External Depth = 15.0 in


There was this site selling that sub that listed displacement as I advised, I have calculated the missing width above, with that sub displacement the difference I noted is now smaller, let me know if everything checks out now.
 

Bronze Member
Username: Shopvac

Post Number: 89
Registered: Jul-10
Ok so I did over the box and here is what I come up with>>

BOX >>>(external) Material thickness 0.75 in
H :12 in
W: 23.5 in
D: 15 in

Vb: 1.4 cuft
Fb: 30.05 hz

PORT >>
H:10.5 in
W:1.5 in
L: 29.625 in
Physical port length : 27.38 inch
Total port volume (air space and wall) : 0.33 cuft

Woofer displacement : 0.074 cu ft

Gross internal volume: 1.804 cu ft


Joe I think the woofer displacement you are using is giving you a higher gross internal volume than mine.
 

Bronze Member
Username: Shopvac

Post Number: 90
Registered: Jul-10
ok joe I did not see you post above, now everything seems closer except for a few decimal points on my part which would have bring it much closer.

As soon as I can build this box and test it, I will be updating on how it sounds.
Once again I really appreciate your help.

Thank you very much.
shopvac.
 

Silver Member
Username: Joe1234

Post Number: 849
Registered: May-09
shopvac you have a problem, the actual physical length of the port is 29.625 in. not 27.38 in.

The effective lenght is denoted as Lve:

Fb = 30.0037002 Hz
Lve = 30.375 in
Vb = 2419.2 in^3, 1.4 ft^3

You can verify this using the equation on which the Torres is based and also is there in the JL Audio tutorial I provided a link for above. You would only be missing Av (the port cross-sectional area) = 15.75 in^2. Maybe that explains why your Vg is still short.

I should thank you as well for keep reading about these small details.

Also wish you luck with that build.
 

Bronze Member
Username: Shopvac

Post Number: 91
Registered: Jul-10
I see what you mean Joe, I think I am going to forget about the torres calculator and do the calculations using the formula.

Will give you feed back.
 

Silver Member
Username: Lord_huggington

Ontario Canada

Post Number: 524
Registered: Oct-10
I've found quirks with the torres & RE calculator. You might as well do it the long way with the 12 volt calculator, doing an end correction yourself. It'll save you a lot of trouble. Hell, I can calculate a box in like 3 minutes on my cell phone because I learned all of the conversions for tuning & space.
 

Silver Member
Username: Joe1234

Post Number: 868
Registered: May-09
The day I checked the RE there were obvious faults in the cutlist and the port displacement. The Torres is horribly unintuitive and impractical, the version I tested had the same elbow losses for 1, 2 or whatever number of turns which simply cannot be. I had to go ahead and do my own coding based on a JL Audio paper to make sure everything is as it should.
 

New member
Username: Ramoncito1969

Donna, TX U.S

Post Number: 4
Registered: Nov-11
B/B recommends 1.324 cu.ft. per sub and tuned to 21.47 hz. on a ported sub. Results are not completely linear though. Upload
 

Bronze Member
Username: Shopvac

Post Number: 93
Registered: Jul-10
ok Joe, so I used the formula and recalculate everything...

Vb: 1.4 cuft
Fb: 30.00 hz

PORT
H:10.5 in
W:1.5 in
L: 29.625 in
Lve : 30.375 in
Total port volume (air space and wall) : 0.391356 cuft

Woofer displacement : 0.074 cu ft

Gross internal volume: 1.865356 cu ft

BOX (external) Material thickness 0.75 in
H :12 in
W: 24.23 in (which will be taken to the nearest fraction of an inch)
D: 15 in

Came out to be almost identical...
Little by little I am getting to understand this whole enclosure building, not qiute there yet lol...but I must say the hardest way is always the best way to learn...
 

Bronze Member
Username: Shopvac

Post Number: 94
Registered: Jul-10
LH, I am starting to find those quirks too...


Thanks Ramon.
 

Silver Member
Username: Joe1234

Post Number: 902
Registered: May-09
Ok shopvac, near enough, I have updated my code, here is a full dump of the output on your box for you to evaluate:

Wood Thickness = 0.75 in

Fb = 30 Hz
Lve = 30.3832992 in
Vb = 2419.2 in^3, 1.4 ft^3

Port Center Line Length = 29.6332992 in
Port Width = 1.5 in
Port Height = 10.5 in
Port Height to Width Ratio = 7.0 ( H/W Should be below 9)
Port Cross-Sectional Area = 15.75 in^2
Port Length = 29.6332992 in
Port Airspace = 466.724462 in^3, 0.27009517 ft^3
Port Internal Assembly Parts Displacement = 209.71125 in^3, 0.12136068 ft^3

Bracing Displacement = 0 in^3, 0 ft^3

Driver Displacement = 127.872 in^3, 0.074 ft^3

Total Displacement = 804.307712 in^3, 0.46545585 ft^3
Gross Internal Volume = 3223.50771 in^3, 1.86545585 ft^3


Enclosure Specifications:

Fb = 30 Hz
Vb = 1.4 ft^3

Subwoofer Mounting = Front Mounted

Port Internal Width = 1.5 in

External Width = 24.24 in
External Height = 12 in
External Depth = 15 in

Cut List:

* All Dimensions in Inches.

* Wood Thickness is 0.75 for all Parts.

External Enclosure Parts:

Front & Back = 24 1/4 x 12
Left & Right Sides = 13 1/2 x 10 1/2
Top & Bottom = 24 1/4 x 13 1/2

L Port Internal Assembly Parts:

Front to Back = 12 x 10 1/2
Extension = 14 5/8 x 10 1/2


It's a lot of work to manually calculate you may want to code a bit, let me know if you want me to suggest a few free tools to do it.

But really I am glad that you did it, you now know for a fact what you are doing, if you deem safe to build on the specs above go ahead.

Any comments, questions or whatever let me know.
 

Silver Member
Username: Joe1234

Post Number: 909
Registered: May-09
Ramon BB allows for different alignments, choose a power aligment if you want to get similar results to those being discussed here.
 

Bronze Member
Username: Shopvac

Post Number: 95
Registered: Jul-10
Indeed its alot of work to manually calculate, a few good tools would certainly help, I have been looking at winISd and doing some reading. If I have more questions I will surely let you know.

Thanks.
 

Silver Member
Username: Joe1234

Post Number: 913
Registered: May-09
Personally I think that you are ready to build unless you want to do a different design.

Now if you want to have your calculations done for you fast take a look at this:

Upload

You can get it here for free and it does not need to be installed:
http://hp.vector.co.jp/authors/VA008683/english/BASIC757E.zip

I wish you a succesful build.
 

Silver Member
Username: Joe1234

Post Number: 915
Registered: May-09
Sorry the above had a small mistake:

LET Portheight = 10.5
LET Portwidth = 1.5
LET Vb = 1.4*(12^3)
LET Lve = 30.38321
LET Av = Portwidth*Portheight
LET Fb = 0.159*SQR( Av*1.84e8/(Vb*(Lve + 0.823*SQR(Av))) )
PRINT "Fb = ";Fb;" Hz"
LET Lv = Lve - Portwidth/2
PRINT "Lv = ";Lv;" in"
END
 

Bronze Member
Username: Shopvac

Post Number: 96
Registered: Jul-10
I will go ahead and build on your specs. as time permits, and give feed back, also will look at the above tool. I might end up giving it to my small brother, he is pushing me to finish the box so he can use it on his system..lol...

I was thinking to upgrade to a 12 in sub running off the T500-1 bdcp @ 1 ohm, can you recommend a good sq 12 in sub with in a budget of around $260 ish, I was looking at the tc sound epic 12 or may be an ID max 12 v.3 which would give me some headroom, if I can come up with some more cash.

dont really know much about them, was just reading up a bit...
 

Silver Member
Username: Joe1234

Post Number: 922
Registered: May-09
Wow shopvac you are going to upgrade before building! Anyways both subs you mention are impressive, those subs need big boxes and go loooow, SQ subs are aligned for a completely flat response to be able to enjoy their transparent response.

For that amp the TC Sounds Epic is perfect and is below 200, I believe it's the best SQ subwoofer below $200 in existence, if your power is undistorted you can drive it well above the 500W rated power. Your amp is underrated so you may be able to drive it to 700W or so.

Up in power below $300 the SSA ICON 12" a very powerful SQ sub on the price range.

The iDMAX is almost 400 new so it's way above, you could get the IDQ which is the 500W version and in your price range.

But I would just listen to your actual project, it may be just what you are looking for.
 

Bronze Member
Username: Shopvac

Post Number: 97
Registered: Jul-10
I was just thinking ahead..lol...

Yes, i think it's best to finish the project first and get some experience.

Thanks Joe.
 

Silver Member
Username: Alonzoub

Post Number: 300
Registered: Apr-10
Just gonna throw this out here real quick. Ill be honest I didn't read the whole thread, just the last cpl posts so if this is irrelevant than go ahead and ignore me... but If you are looking for the IDMAX12v3 D2 (not the D4)... it is available http://www.sonicelectronix.com/item_20231_Image-Dynamics-IDMAX12-V.3-D2.html for just around $280 brand new. Just click "Make an Offer" and lowball it around 250 I think and it will make you a counteroffer. I wudn't expect this deal to be around very long so take advantage of it while you can.
 

Silver Member
Username: Joe1234

Post Number: 927
Registered: May-09
For $280 I would definitely consider it. It can deliver about the same output on 500W as a Fi Q would on 1000W and keeping SQ, also it goes lower like the SSA ICON and the TC.
 

Bronze Member
Username: Shopvac

Post Number: 98
Registered: Jul-10
wow this seem very tempting...
 

Bronze Member
Username: John253a

Aust.

Post Number: 91
Registered: May-11
280 idd get it and tune it around 38-40hz,
It wont be as loud in the lows but will be better allround and set amp at 70hz, you cant go wrong with that.

If tuned heaps at 30-35hz and in a everyday car that lissiin to most music 40hz is what ive found to work better and louder over a larger range
 

Silver Member
Username: Joe1234

Post Number: 944
Registered: May-09
Shopvac I still have a problem with you sub displacement, could you please check this link??

http://www.rockfordfosgate.com/rftech/library/2011/5_Subwoofers/4020117-0_P3Subs -MAN_Rev2.pdf

Please check physical dimension G on page 4.

Thanks.
 

Bronze Member
Username: Shopvac

Post Number: 99
Registered: Jul-10
Hi Joe, that displacement (0.127 cu ft) on the link is for the newer punch subwoofer P3D2-10.

I have the older model (discontinued) P3D210, no dash between the 2 and 10, with displacement 0.074 cu ft

here >>>
http://www.rockfordfosgate.com/rftech/box_advisor.asp?locale=en_US&p_status=disc ontinued&p_units=standard&p_series_id=31&p_item_id=108286
 

Silver Member
Username: Joe1234

Post Number: 951
Registered: May-09
Thanks for looking into it shopvac, the funny thing is that on page 5 of the same manual above(I mean just the next page) it says 0.074.

I don't really know what are these guys up to, but, ok 0.074 it is (I guess).
 

Bronze Member
Username: Shopvac

Post Number: 100
Registered: Jul-10
I havent had a chance to work on my project as yet, and still havent decided if I am going to get the idmax or tc sub as yet.

I also been looking at the idea of kerfing the slot port for the r/f sub, (I know, I want to do too much..lol..)....
 

Silver Member
Username: Joe1234

Post Number: 952
Registered: May-09
Ok shopvac take your time to make your choices it usually pays off, and as for your box if you want to do a super fine job then go ahead.

The Kerfing thing, damn I guess you will need to get good with tools and have access to them. Wish you luck on that.
 

Silver Member
Username: Shopvac

Post Number: 101
Registered: Jul-10
Thanks Joe.

Yea, its weird, that they are 2 different displacement on that manual.
The manual that came with my sub says 0.074 on both page 4 and 5, I guess I will have to work with the 0.074
 

Silver Member
Username: Joe1234

Post Number: 958
Registered: May-09
Yes I guess the guy editing that manual was drunk at the time... so 0.074 it is.
 

Silver Member
Username: Shopvac

Post Number: 103
Registered: Jul-10
lol...
 

Silver Member
Username: Shopvac

Post Number: 105
Registered: Jul-10
Hi Joe I want to also try a box with an aero port, now with Vb =1.4
and tuning freq @ 30 hz, if I try to use a 4'' diameter port there is no way it would fit, its too long.

So I was thinking a 3'' aero port (length =13.924 in, from PSP calculator), which would fit good into the box, however I dont know if its sufficent port area, hence port noise?

I would very much appreciate if you can check if the air flow would be good with a 3'' dia port at 400w rms for the P3D210. wired to 1 ohm load. Please let me know if anymore info is needed.
Thanks.
 

Silver Member
Username: Joe1234

Post Number: 995
Registered: May-09
41 m/s @28Hz
 

Silver Member
Username: Shopvac

Post Number: 106
Registered: Jul-10
so, is 41 m/s @ 28 Hz good?

Is it safe to say to say that I can tune to 30 Hz with the 3'' diameter aero port, or should I tune to 28 Hz? I am a little confused lol...
 

Silver Member
Username: Joe1234

Post Number: 997
Registered: May-09
A single 3" would be a failure producing substantial port noise. You would need to redesign a lot of that box to have something viable, likely you will need to port laterally. Also the slot design we have been talking about came a bit short in port area, it should be 1 10/16 instead of 1 1/2 by an estimate that says that the port cross-sectional area divided by Vb should give 12 to 16.
 

Silver Member
Username: Shopvac

Post Number: 107
Registered: Jul-10
Thanks Joe.
 

Silver Member
Username: Joe1234

Post Number: 1000
Registered: May-09
For the estimate above you can do the same for aeros the result of Port Area/ Vb only need to be 10 -13 since they are usually more silent (the bi-flanged ones anyways).
 

Gold Member
Username: Joe1234

Post Number: 1006
Registered: May-09
Forgot to say, by doing that estimate you don't need to look at the vent airspeed, in this case for a 3" vent: 7.06/1.4 = 5.04 and you would need to reach 10 so it's a no go.
 

Silver Member
Username: Shopvac

Post Number: 108
Registered: Jul-10
ok Joe good info thanks.
 

Silver Member
Username: Shopvac

Post Number: 109
Registered: Jul-10
Upload

Joe here is my new box, larger port area and tuned to just a fraction above 30Hz
 

Gold Member
Username: Joe1234

Post Number: 1039
Registered: May-09
Ok shopvac I see a few things that I would have done differently, 1. the port internal end is too near of the wall IMO, 2. there are a few symmetries I would make all dims different and move the sub to a side this is done to prevent big resonances from appearing.. as before just design guidelines not "must do" rules, I ran your previous external dims just making the port a little wider the outcome is this:

Enclosure Specifications:

Fb = 30 Hz
Vb = 1,4 ft^3

Subwoofer Mounting = Front Mounted

External Height = 12 in
External Width = 24,97 in
External Depth = 15 in

Port Width = 1 5/8 in

Cut List:

* All Dimensions in Inches.
* Wood Thickness is 3/4 for all Parts.

External Enclosure Parts:

Front & Back = 25 x 12

Left & Right Sides = 13 1/2 x 10 1/2

Top & Bottom = 25 x 13 1/2

L Port Internal Assembly Parts:

Front to Back = 11 7/8 x 10 1/2
Extension = 17 1/4 x 10 1/2


And here is the design data:

Enclosure Technical Data:

Fb = 30 Hz
Vb = 1,4 ft^3

Flush Mount = 0 Yes = 1, No = 0
Dual Chamber = 0 Yes = 1, No = 0

External Height = 12 in
External Width = 24,97 in
External Depth = 15 in

External Volume = 2,601 ft^3

Wood Thickness = 0.75 in

Port Width = 1,625 in
Port Height = 10,5 in
Port Height to Width Ratio = 6,462 (<9)
Port Cross-Sectional Area = 17,0625 in^2
Port Center Line Length = 32,242 in

Port Airspace Displacement = 0,318 ft^3
Port Parts Displacement = 0,133 ft^3
Bracing Displacement = 0 ft^3
Driver Displacement = 0,074 ft^3
Total Displacement = 0,525 ft^3

Gross Internal Volume = 1,925 ft^3


I realize many poeple don't want to cut the port on the baffle surface so I may need to change my code to allow for a " vertical sandwich" assembly like you did. Also great job with SketchUp I really don't like very much that proggy. Let me know if you happen to catch something wrong somewhere! Also! check the sub cutout is a bit short add 1/8. No one here is as interested to get this right as you do, are you going to do this professionally?
 

Silver Member
Username: Shopvac

Post Number: 110
Registered: Jul-10
Hi Joe, thanks for the kind comments.

I choose those dimensions because I have a grill for this sub which is 11" OD, hence why I did not use 12" external height as was previousely used, reason being is that I dont want the grill to be that close to the front; top and bottom edges, 13 1/2 '' would give me enough room and would look some what proportionate also, I wanted the box to be symmetrical in terms of height and width.

I have realised that the port internal end is close to the side wall (1.75") but not much I can do there with the dimensions chosen. Alternatively, I would have to redo the entire box.

I am not clear on moving the sub to a side to prevent big resonances, is it moving it towards the left or right on the front of the box, or do you mean moving it to one of the sides of the box and make appropriate changes to all dimensions of the box?

I also, recheck the sub cutout its 9".

I would like to do it professionally if I could...lol..."if", I have always been interested in this since I was a kid but never had a chance to take it up. I guess I took up the wrong profession...lol...

And, by the way it took me a while to figure out sketchup..an entire weekend ..lol..
 

Gold Member
Username: Joe1234

Post Number: 1046
Registered: May-09
Ok shopvac I understand why you want those dims, yes I would place the sub in either side (but in the same face), best in the opposite side of the port to break symmetry everywhere you can.

There is this rule on aeros which is to leave 2-3 port diameters unobstructed in front of the internal end, I use a similar criteria for slots, no less than two times the port width just to be safe and prevent potential detuning. But probably you will want to ask around before taking the advice.

I calculated two workarounds in case you can confirm the above is relevant:

1,6 ft^3@30 Hz

External Height = 13,5 in
External Width = 27,73 in
External Depth = 13,5 in

Port Width = 1 5/8 in

L Port Internal Assembly Parts:

Front to Back = 10 3/8 x 12
Extension = 18 1/2 x 12


Or:

1,4 ft^3@33 Hz

External Height = 13,5 in
External Width = 24,93 in
External Depth = 13,5 in

Port Width = 1 5/8 in

L Port Internal Assembly Parts:

Front to Back = 10 3/8 x 12
Extension = 16 1/2 x 12


I keep calculating these things for fun (very fast since it's all now coded) but if you happened to find some infos on the subject I'll be glad to know.
 

Silver Member
Username: Shopvac

Post Number: 111
Registered: Jul-10
Thanks Joe.

I would certainly look up the subject and let you know if I find anything different. Also, I think I would go with the 1.4 cuft @ 33 Hz option, looks like it would fit nicely in my application. And for practise I will do the calculation and will post drawing etc.
 

Silver Member
Username: Shopvac

Post Number: 112
Registered: Jul-10
Sorry, one question with regards to sub placement "best in the opposite side of the port to break symmetry everywhere you can".

Should I move the sub closer to the external end or internal end of the port on the front face?
 

Gold Member
Username: Joe1234

Post Number: 1054
Registered: May-09
Upload

Either way (sorry) the reason to put it on the opposite side is that for SPL subwoofers, the airflow of the port helps cooling down the coils.
 

Silver Member
Username: Shopvac

Post Number: 113
Registered: Jul-10
Ah more efficent I see, awesome Joe thanks.
 

Silver Member
Username: Shopvac

Post Number: 114
Registered: Jul-10
Another advantage of doing this from what I can see, is that with the sub in the corner of the box, it's supported more structurally as compared to placement of sub in the center, especially on boxes with out bracing.
 

Gold Member
Username: Joe1234

Post Number: 1057
Registered: May-09
Yes and also there is this very easy to make and very effective brace that I have seen added, specially if a second sub was to be put:

Upload
 

Silver Member
Username: Shopvac

Post Number: 115
Registered: Jul-10
Final Box design for Rockford Fosgate P3D210 1.4 cuft tuned to 33 Hz
Upload
 

Gold Member
Username: Joe1234

Post Number: 1067
Registered: May-09
Looks perfect to me, just keeping in mind that the cutout for the sub is 9 1/8" minimum. I was just curious, did you draw it only or fully checked the design?
 

Silver Member
Username: Shopvac

Post Number: 116
Registered: Jul-10
Hi Joe, yes I have fully checked the design and confirms it's within all recommendations.

I have also triple checked the sub cutout/ mounting diameter and it is 9'' diameter, the 9 1/8'' cutout diameter is for the newer P3D2-10.
 

Gold Member
Username: Joe1234

Post Number: 1069
Registered: May-09
"the 9 1/8'' cutout diameter is for the newer P3D2-10" lol.. once again me looking at the other manual...

I have manually checked the drawing dims you intend to build on and everything is ok.. my code rounded external width to: 24 15/16 This does not need to be adressed at all. Results are:

Vb = 1,39605208 cuft
Port centerline length = 30 in

Well, you are the only one who knows what goes into a design from those who have asked and I don't know how could you take so much for a box design!

If you have a chance picture your build!
 

Silver Member
Username: Shopvac

Post Number: 118
Registered: Jul-10
Thanks for rechecking the dimensions Joe.

Well, I dont like to do anything with out understanding atleast the basic principles of how it should be done , especially things that I am interested in, and I could not have done it with out your help. I have learnt much more than I could have asked for, not many would help as you did, and they have their reasons why, which is understandable. I will try to picture the build if I do get the chance. And if I find anything new, I would certainly post.

Thanks Joe, I really appreciate everything.
 

Silver Member
Username: Shopvac

Post Number: 139
Registered: Jul-10
Hey Joe so I finally finished this box and tested it, sounds awesome, just what I wanted !! I know it more than about time..lol...

Thanks once again for all the help !!!

Upload
 

Gold Member
Username: Joe1234

Post Number: 1596
Registered: May-09
Glad you got it done Shopvac looks impressively well made.
 

Silver Member
Username: Shopvac

Post Number: 140
Registered: Jul-10
Thanks Joe ! Now every guy wants me to make a box for them down my street ..lol...
 

Gold Member
Username: Joe1234

Post Number: 1600
Registered: May-09
Maybe you can start a secondary business with this!
 

Silver Member
Username: Shopvac

Post Number: 141
Registered: Jul-10
Good idea, I have been thinking about it, still needs to learn more...lol..
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