subwoofer enclosure what size thiele/small included

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Hi i have an Eminence driver 12" LTD-MK2 subwoofer from my in car thump thump days,

can not find a great deal of information on the internet I purchased it around 2001 it has not been used for years so i am trying to find out what size enclosure i need to build.

do not realy want to throw it away;)

It is to help out on my lampizator/endorphin p17 open baffle build eminence alpha 15A with saba greencones, the two alphas arrived this morning so got some work to do building baffle etc.And a bit of home theatre crash bang wallop

here is the parameters taken from this website

https://www.google.co.uk/url?sa=t&r...0IDYDA&usg=AFQjCNHNlbFfiGsBjHmmo77dFG9rpEMZMQ

https://www.google.co.uk/url?sa=t&r...0IDYDA&usg=AFQjCNHcjrPp2ttBN5dW_YxisPS9UhZrzQ


THIELE SMALL settings and speaker level on IRC EMINENCE LTD-12MK2:

Definition Parameter Values Formulas. MKSA units
Resonance Frequency F s 37.85 Hz Value of the database
Air volume equivalent to the elasticity of the suspension V AS 123.18 L Value of the database
Coil resistance at DC R e 2.65 Ohms Value of the database
Internal resistance of the amplifier R g 0.00 Ohms Damping factor of 8 Ohms 200000
Crossover resistance R f 0.00 Ohms If 0: No active filter or
Coefficient mechanical overvoltage Q ms 10.040 Value of the database
Coefficient of electrical overvoltage Q es 0.510 Value of the database
Coefficient of total overvoltage Q ts 0485 Q * Q es ms / (Q + Q es ms)
Type calculated F s / Q ts 78.0 Hz F s / Q ts
Type GRAVE IN TEST
Surface of the membrane S d 532.36 cm 2 Value of the database
Radius of the membrane R d 13.02 cm root (S d / ft)
Equivalent standard diameter D iameq 31 cm Rules for calculating the diameter
Compliance acoustic suspension C ase 8735.2 Ncm 5 V AS / (R * o C 2)
Total mass of acoustic diafragme M as 20.2 kgm 4 1 / ((2 * Pi * F s) 2 ° C as)
Mechanical moving mass M ms 57365 g (C * S d / (2 * Pi * F s)) 2 * R o / V AS = M * S as d 2
Mechanical mass frontal radiation M mrf 7.022 g (8 * R * R o d 3) / 3
Mass of the membrane M md 50343 g M -M ms mrf
Strength R ms 1359 Kg / s 2 * Pi * F * M s ms / ms Q
Compliance of the suspension C ms 0.308 mm / N 1 / (2 * Pi * F s) 2 / M ms
Stiffness of the suspension K 3244 N / m 1 / C ms
Force factor BL 8419 N / A (2 * Pi * F * M ms * s R e / Q es) 1/2
BL / M ms BL / M ms 146.8 kg.m / s 2 / A This is not a selection criterion
Linear stretch of the membrane X max ± 5.60 mm Value of the database
X max PP pp 11.20 mm 2 * X max
Air volume displaced by the membrane V d 298.12 cm 3 S d * X max
Displacement of the point of the rest
upright membrane X Green 0.06 mm ® * M * C 9.81 ms
Yield% Makes 1.273% (4 * Pi 2 / C 3) * (F s 3 * AS V / Q es) * 100
Constant sensitivity Cste direction 112.13 dB 10 * LOG (R o * C / 2 / Pi) -20 * LOG (2 * 10 -5)
Sensitivity in 2 * Pi steradian
Valid in the medium to below 420 Hz
for operation in piston SPL 98.0 dB / 2.83V / m 10 * LOG (Makes / 100) +112.13
+ 10 * LOG (8 / (R + R e g + R f))
93.2 dB / W / m 10 * LOG (Makes / 100) +112.13
Sensitivity in 4 * Pi steradian (with reservation)
Valid in the low, below a frequency
which depends on the size of the front panel. SPL 94dB / 2.83V / m 10 * LOG (Makes / 100) +112.13
+ 10 * LOG (8 / (R + R e g + R f)) - 4
89.2 dB / W / m 10 * LOG (Makes / 100) + 112.13-4
Power cut-off frequency F e 541 Hz 1 / (2 * pi * (T / (R + R e f g + R)))
All values ​​in the table are calculated from the values ​​stored in the database, F s, AS V, R e, Q ms, Q es, S d, T and X max.



Parameters for the simulation in an electric software EMINENCE LTD-12MK2
Definition Parameter Values Formulas
MKSA units
Equivalent resistance R es 52.17 Ohms B 2 L 2 / R ms
Equivalent inductance T he 21.85 mH B * C 2 L 2 ms
Equivalent capacity T hese 809.24 uF M ms / B 2 L 2
All values ​​in the table are calculated from the values ​​stored in the database, F s, AS V, R e, Q ms, Q es, S d, T and X max.

thanks guys
 
Those old Eminence subs (did you buy it from Maplin?) were really just cosmetically modified PA drivers. As such, they are not really suitable for home subwoofer use. Resonance frequency is too high and they need a big box.

How they got away with marketing them as car subs... well the market back then was a lot less clued up and developed.
 
i bought just one from a car audio shop in lincoln

now i know eminence did a range of speakers with blue and green foam surrounds with numbers printed across the the dust cap its not one of them

An externally hosted image should be here but it was not working when we last tested it.


An externally hosted image should be here but it was not working when we last tested it.


An externally hosted image should be here but it was not working when we last tested it.


here is the email response from eminence when i enquired

Here are the T/S parameters for LTD-12MK2:

05-RE OHMS 2.65 13-FS HZ 37.85
06-LE MH .78 14-MMS GMS 57.10
07-QM 10.04 15-CMS mm/N .3095
08-QE .510 16-RMS NS/M 1.3536
09-QT .480 17-VAS LTRS 123.18
10-XMAX MM 5.60 18-SD SCM 532.36
11-BL TM 8.44 19-EBP 74.9
12-EFF % 1.27 20-SPL dB 93.1


Best Regards,


ANTHONY LUCAS
Design Engineer/Technical Support
 
Last edited:
13-FS HZ 37.85
14-MMS GMS 57.10
15-CMS mm/N .3095
16-RMS NS/M 1.3536
17-VAS LTRS 123.18
18-SD SCM 532.36
19-EBP 74.9
20-SPL dB 93.1

Hi Charlie,

Here is a suggestion:

b:)
 

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GM

Member
Joined 2003
Hio Charlie,

Better late than never...

b:)

PS: Hope my cryptic pixels makes sense.. :D


crypticly challenging:eek:

thank you very much for getting back regards design of enclosure

think i have got it about right

An externally hosted image should be here but it was not working when we last tested it.


An externally hosted image should be here but it was not working when we last tested it.


a few weeks before i get to build it as i am expecting delivery of 2 units of 2x4 minidsp to play about with my open baffle speakers.

will update as and when kind regards
 
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