Speaker encolure - I'm I correct?

[patate91]

Speaker enclosure - I'm I correct?

I'm planning to build my second pair of speaker cabinets and I would like to validate that I'm on the right way and that I understand what I'm doing.

First I'm trying to build something close to pioneer exclusive 2402. I found plans on internet for the woodhorn and enclosure on Yuichi's Arai web site. The wood horn will sit on top outside the bass cabinet. The bass cabinet will be 170 liters tuned to 35hz. (Round vent ports instead of rectangle).

After calculating the internal volume according to plan I have ~ 189 liters.

I guess I have to calculate the loss from woofer, vent ports and bracing to get 170 liters.

1- Is it right to not calculate the volume of vent ports?

2- the woofer is tad tl-1602 - on spec sheet that I found on internet there's a " Piston Area (sq m)". Is it the volume that I have to "remove"??

3- the damping material should not be count as a loss.

Thanks

 

[DF96]

You might get a quicker response in one of the speaker forum areas? Your question appears to be about design, not construction.

 

[ODougbo]

Patate, you're getting warmer!
Download WinISD (free) and you can insert the woofer parameters and design a box, port, etc.
The box size is "net" so need to subtract woofer and port.

woofer specs:TL-1602 Pioneer - - Computer

 

[AndrewT]

the port volume should NOT be included in the box volume.

If your port is a 4mm thick 100mm tube, that is 150mm long, then it's port volume is 1.18litres (Pi/4*1²*1.5).
The port tube has a volume of Pi/4*{1.08²-1²}*1.5=0.2litres.

If you box volume needs to be 170litres, then for an internal port you must add on 1.18 & 0.2 to gives a total volume of 171.38litres. Then adjust for bracing and corner battens.

 

[Sonce]

2- the woofer is tad tl-1602 - on spec sheet that I found on internet there's a " Piston Area (sq m)". Is it the volume that I have to "remove"??

No, Piston Area = Sd, active area of the woofer's cone membrane.(Sd=D^2pi/4, where D is an active diameter of the cone). It is a Thiele-Small parameter which you must put in the WinISD software, along with other woofer parameters.

 

[patate91]

Thank you for all the anwsers.

I'll get WinISD and I'll give it a try.

I'm almost sure that Mr Arai's design is correct but this time I want to understand a step further what I'm doing. Also, since I'm modifying the vent ports, it would be a good thing to validate it.

 

[patate91]

Here's what I got with WinISD : I think the response is pretty flat from 35 to 900 (TN-4 crossover at 900hz). I'll try to get close to 170 liters. Still need to calculate woofer volume to confirmed Yuichi's plan and to get bracing volume.

From a web site I tried to calculate vent port but I wasn't having the same lenght as in WinISD. But at 156mm long for 4'' diameter it seems pretty accurate. (from the other site I had 235mm long and 4'' diameter)

Driver : TAD TL-1602
Project by : Yan
Project for : you
--
Number of drivers : 1
Box type : Vented
Box size : 170,0 l
Tuning frequency : 35,00 Hz
Vent : 2 vent(s)
0,156 m length for each
0,102 m round


Relative
Freq Gain SPL
[Hz] [dB] [dB]
20,00 -21,01 76,49
25,00 -13,94 83,56
30,00 -7,96 89,54
35,00 -3,58 93,92
40,00 -1,54 95,96
45,00 -1,12 96,38
50,00 -1,19 96,31
55,00 -1,32 96,18
60,00 -1,40 96,10
65,00 -1,42 96,08
70,00 -1,41 96,09
75,00 -1,38 96,12
80,00 -1,33 96,17
85,00 -1,27 96,23
90,00 -1,21 96,29
95,00 -1,15 96,35
100,00 -1,09 96,41
105,00 -1,03 96,47
110,00 -0,97 96,53
115,00 -0,92 96,58
120,00 -0,86 96,64
125,00 -0,82 96,68
130,00 -0,77 96,73
135,00 -0,73 96,77
140,00 -0,69 96,81
145,00 -0,65 96,85
150,00 -0,62 96,88
155,00 -0,59 96,91
160,00 -0,56 96,94
165,00 -0,53 96,97
170,00 -0,51 96,99
175,00 -0,48 97,02
180,00 -0,46 97,04
185,00 -0,44 97,06
190,00 -0,42 97,08
195,00 -0,40 97,10
200,00 -0,38 97,12
205,00 -0,37 97,13
210,00 -0,35 97,15
215,00 -0,34 97,16
220,00 -0,32 97,18
225,00 -0,31 97,19
230,00 -0,30 97,20
235,00 -0,29 97,21
240,00 -0,28 97,22
245,00 -0,27 97,23
250,00 -0,26 97,24
255,00 -0,25 97,25
260,00 -0,24 97,26
265,00 -0,23 97,27
270,00 -0,22 97,28
275,00 -0,21 97,29
280,00 -0,21 97,29
285,00 -0,20 97,30
290,00 -0,19 97,31
295,00 -0,19 97,31
300,00 -0,18 97,32
305,00 -0,18 97,32
310,00 -0,17 97,33
315,00 -0,17 97,33
320,00 -0,16 97,34
325,00 -0,16 97,34
330,00 -0,15 97,35
335,00 -0,15 97,35
340,00 -0,14 97,36
345,00 -0,14 97,36
350,00 -0,14 97,36
355,00 -0,13 97,37
360,00 -0,13 97,37
365,00 -0,13 97,37
370,00 -0,12 97,38
375,00 -0,12 97,38
380,00 -0,12 97,38
385,00 -0,11 97,39
390,00 -0,11 97,39
395,00 -0,11 97,39
400,00 -0,11 97,39
405,00 -0,10 97,40
410,00 -0,10 97,40
415,00 -0,10 97,40
420,00 -0,10 97,40
425,00 -0,09 97,41
430,00 -0,09 97,41
435,00 -0,09 97,41
440,00 -0,09 97,41
445,00 -0,09 97,41
450,00 -0,08 97,42
455,00 -0,08 97,42
460,00 -0,08 97,42
465,00 -0,08 97,42
470,00 -0,08 97,42
475,00 -0,08 97,42
480,00 -0,07 97,43
485,00 -0,07 97,43
490,00 -0,07 97,43
495,00 -0,07 97,43
500,00 -0,07 97,43
505,00 -0,07 97,43
510,00 -0,07 97,43
515,00 -0,06 97,44
520,00 -0,06 97,44
525,00 -0,06 97,44
530,00 -0,06 97,44
535,00 -0,06 97,44
540,00 -0,06 97,44
545,00 -0,06 97,44
550,00 -0,06 97,44
555,00 -0,06 97,44
560,00 -0,05 97,45
565,00 -0,05 97,45
570,00 -0,05 97,45
575,00 -0,05 97,45
580,00 -0,05 97,45
585,00 -0,05 97,45
590,00 -0,05 97,45
595,00 -0,05 97,45
600,00 -0,05 97,45
605,00 -0,05 97,45
610,00 -0,05 97,45
615,00 -0,05 97,45
620,00 -0,04 97,46
625,00 -0,04 97,46
630,00 -0,04 97,46
635,00 -0,04 97,46
640,00 -0,04 97,46
645,00 -0,04 97,46
650,00 -0,04 97,46
655,00 -0,04 97,46
660,00 -0,04 97,46
665,00 -0,04 97,46
670,00 -0,04 97,46
675,00 -0,04 97,46
680,00 -0,04 97,46
685,00 -0,04 97,46
690,00 -0,04 97,46
695,00 -0,04 97,46
700,00 -0,04 97,46
705,00 -0,03 97,47
710,00 -0,03 97,47
715,00 -0,03 97,47
720,00 -0,03 97,47
725,00 -0,03 97,47
730,00 -0,03 97,47
735,00 -0,03 97,47
740,00 -0,03 97,47
745,00 -0,03 97,47
750,00 -0,03 97,47
755,00 -0,03 97,47
760,00 -0,03 97,47
765,00 -0,03 97,47
770,00 -0,03 97,47
775,00 -0,03 97,47
780,00 -0,03 97,47
785,00 -0,03 97,47
790,00 -0,03 97,47
795,00 -0,03 97,47
800,00 -0,03 97,47
805,00 -0,03 97,47
810,00 -0,03 97,47
815,00 -0,03 97,47
820,00 -0,03 97,47
825,00 -0,03 97,47
830,00 -0,03 97,47
835,00 -0,02 97,48
840,00 -0,02 97,48
845,00 -0,02 97,48
850,00 -0,02 97,48
855,00 -0,02 97,48
860,00 -0,02 97,48
865,00 -0,02 97,48
870,00 -0,02 97,48
875,00 -0,02 97,48
880,00 -0,02 97,48
885,00 -0,02 97,48
890,00 -0,02 97,48
895,00 -0,02 97,48
900,00 -0,02 97,48

 

[ODougbo]

Patate91,

Might be over thinking this speaker and port volume here with a 170L box.
That is more of an issue with the car sub boxes, which are minuscule in comparison.
I would just compare it to a 1 liter or 2 liter plastic water bottle and take a educated guess
However if you really want to nail the woofer volume down, there's the bag and bucket of water ploy.

 

[patate91]

Not sure about water but maybe if I have spare time I'll go with packaging "noodle".