My first attempt to design a sub. Can you help me with some tips please...

[Naveenbnc]

Hi All, I'm trying to design my first sub enclosure for 6" Iwai driver. I'm using BassBox6 Pro.

Can you help me with a few tips please...

1. Resonance freq. (Fs) of the driver is 49.5 hz. As we increase the box size, the box tuning freq. (Fb) Is decreasing. How far we can decrease it ?? I mean.... If we decrease the Fb too much, are we pushing the driver to its limits??

2. Similarly, is there any acceptable range of F3, (at 3db down point) based on the Fs of the driver?

3. How much air velocity at the vent is safe??

Please bear with me if the questions are flawed. I'm totally new to everything, right from TS parameters to the basic design fundamentals. I'm in the beginning stage of learning.

The reason for asking is to identify if the software is giving some results that are too much deviated from the theoretical values.

Thanks in advance
Naveen

 

[Naveenbnc]

Wow...looks very informative...thanks a lot yogibear !!!!

 

[Kannan]

You will have to be accurate with port length and dia. If is better to go for dual flanged ports. You can easily make ports with PVC pipes and a heat gun.

Use silicon sealent across all the joints as air leakage will severely affect performance.

 

[Naveenbnc]

thank you very much Kannan, I will surely try your suggestions.

 

[viki_v2]

Have you measured the Ts specs. Can you post them.

 

[Fantastic]

Bass Box6 is good. It has a provision of calculating all parameters if you have only a few. Check it under driver parameters. You do need the real TS parameters. It will most likely be different from the ones you find on the spec sheet. Tuning too low doesn't help. You can see it on Bass Box easily. Start with the suggested box size for the 'real' TS parameters. Ducted or sealed depends on the TS parameters. There is always a bit of leeway in this.Bass Box also has a calculator to measure the TS parameters but then there are lots of other free calculators on the Net. Using the added mass method is the easiest and I feel , most accurate. Run the driver with a low frequency signal ( 40 Hz) at a reasonable amplitude ( +/- 5mm ?) for a few hours before measuring.