Vifa 12" sub design

[shporsche]

Hi guys,
I'm going to be using Vifa's 12" sub for a home audio subwoofer.
However I dont have a box building program and I have hardly any download left to get one.

The company provide a design already however they have a chart that is all mixed up, so I dont know what the exact dimensions are.

Vifa 12" Subwoofer - Jaycar Electronics


Can someone please inform me of the recommended enclosure size and port length?

This would be very helpfull thanks.

[bjorno]

Originally Posted by shporsche

..Can someone please inform me of the recommended enclosure size and port length?

Hi shporsche,

FYI, See the first picture: A 'Wolksvagen' BR and compare with the 'Porsche' version: a T-TQWT in the next picture.

b

[shporsche]

Originally Posted by bjorno

Hi shporsche,

FYI, See the first picture: A 'Wolksvagen' BR and compare with the 'Porsche' version: a T-TQWT in the next picture.

b

Thanks for your help bjorno

[bjorno]

Originally Posted by shporsche

Thanks for your help bjorno

Hi shporsche,

Forgot to mention the need for stuffing’s in the port: See the picture.

It’s not much but some is needed to reflect the MJK simulation and IME best done by trial and error.

Sometimes a similar satisfactorily result is achieved by omitting the port stuffing and just pushing the box stuffing’s to slightly obstruct the inside of the port.

b

[D1GGY]

A bit of thread resurrection here...

I have just purchased a "VIFA" CS2353 driver and have been researching how best to use it and came across this thread.

I have a couple of questions that i hope can be answered.

a - What advantages would such a design have over a ported box that i am more familiar with.
b - It is not clear to me what the dimensions of the cabinet are, are all three images related to the same design?

Cheers,

MG

[D1GGY]

Ok so i have been doing some research online and now understand the T-TQWT approach, I am now more interested in the design, seems a more elegant design than a box and some pipe!

I have downloaded hornresp and with a view to replicate Bjorno's findings so that i can start to dimension the enclosure.

Build thread to follow hopefully

[D1GGY]

Ok - so i have downloaded Hornresp and have inputted the data and can see how Bjorno got the outcome he has, alothough i do not understand the theory ebhind it, but can replicate the numbers he arroved at...

I am wanting to build this sub as a double fold so that it retains some WAF, but i am unsure about how to start designing the cabinet. Some searching on the net has not yet provide me with a step by step process on how to take the model information and design and construct the enclosure. Can someone point me in the right direction on how i go about designing the enclosure from the model please, as i am clearly searching for the wrong thing!

As an alternative i have seen some solutions provided by genourous contributors on this forum to modelling and was wondering if someone would be that way inclined to help me out in the same way and to also offer an explanation as to how they developed the enclosure from the data model.

Thanks

MG

[bjorno]

Originally Posted by D1GGY

..i am unsure about how to start designing the cabinet. Some searching on the net has not yet provide me with a step by step process on how to take the model information and design and construct the enclosure. Can someone point me in the right direction on how i go about designing the enclosure from the model please, as i am clearly searching for the wrong thing!..

Hi MG,

We are using HR to simulate T-TQWT's but as this sub should be stuffed with damping material from the closed end half-ways down the line:
You need in the real world to adjust the offset predicted by HR.

This is done using MJK:s program.(The first of pictures).

The second picture is showing a step by step approach on how to do a double fold. Note only 4 sections is used, HR can use up to 5: So re-labeling is necessary if to be used for a 4 section simulation.

b

[D1GGY]

Bjorno - thanks for your comprehensive response. I have spent some time to understand how to construct the enclosure and am getting stuck.

i have gone down two paths...the first;-

in trying to work out the height of the enclosure the L23 length seems very short 30.4mm - perhaps i am reading it incorrectly but my understanding at the moment is that to get the enclosure height for one fold i need to calulate as fllows X = 10cm + L34 - - 100mm + 109mm = 209mm or 21cm This seems very short to me.
I then try to use L12 which is 102cm - closer to the the 'width depth' table.

The second:-

is that the 'width depth' table has all the information i need to build the cabinet - except that the overall lengths for each of the folds seems to be different - 102.6cm - 109 cm and 16cm...

Either way i am lost...

The bit i do get however is that the enclosure will be 32cm wide (plus watever thickness my wall material is)

Finally (for now ;-) ) - Would a good quality 18mm ply be a suitable enclosure material?

Thnaks for your patience..

Mark

[bjorno]

Originally Posted by D1GGY

..The bit i do get however is that the enclosure will be 32cm wide (plus watever thickness my wall material is)..

..Finally (for now ;-) ) - Would a good quality 18mm ply be a suitable enclosure material?..

Hi Mark,

My answer: Yes and Yes.

Before I start answering your other questions: I've submitted a new picture that might bring a better clarification on how to fold:

b