Reading TS Parameters

[theJman]

I'm thinking about taking the plunge and building my own subwoofer. I've done a tremendous amount of research thus far, so I have a reasonably good understanding of what I need to do and how best to go about it. One area I'm not terribly comfortable with though is deciphering all the information contained within the TS parameters.

My intention is to create a ported sub approximately 14-15" in each dimension (H, W, D), using a 10" driver and a 200 watt amp. I know how to interpret a few of the TS parameters -- like Fs -- so I understand some of the specifications, but several of the ones related to appropriate cabinet size and type (bass reflex vs acoustic suspension) I'm not entirely certain of.

Can someone tell me which of the TS parameters I should concentrate on to build a ported sub about the size I need? Also, what ranges or tolerances (plus and minus, in other words) those parameters should be within in order to be considered good for my application? Just some general guidelines is all I really need. Once I have a direction I'll take it from there.

[TundraLTD]

There is no way to answer your question well. You can look for a speaker that will fit a type of design but you seem to have already chosen the box type and volume

Check these out:

Thiele-Small Explained?

Thiele-Small

If you have a driver in mind there are a few people here that will help you with a design that will blow you away!

[theJman]

There is no way to answer your question well. You can look for a speaker that will fit a type of design but you seem to have already chosen the box type and volume

Actually, room layout and limited placement options have decided for me.


Check these out:
Thiele-Small Explained?
Thiele-Small

I will indeed. Thanks for the links.


If you have a driver in mind there are a few people here that will help you with a design that will blow you away!

I don't have a driver in mind just yet. I wanted to understand how to read the parameters before I got my heart set on something, only to find it wasn't suitable. Once I have a better idea of how to decipher those numbers then I'll probably do that; ask what others think of my choice.

[Conrad Hoffman]

It's difficult to "read" them. What you need to do is get a box program- there are lots that are free, or very good ones you can pay for. Run some designs using the parameters for various drivers and see what you get. IMO, deciding on a specific box and looking for a driver is an exercise in frustration. Compile a list of drivers that look interesting, then run box designs for them. With luck, something will stand out as a winner. (run both sealed and ported designs)

[revboden]

That size will dictate using sealed box or passive radiator as you cannot fit a port long enough to tune the enclosure lower than a woofer.

[TundraLTD]

if you have only 13-14" cube to work with a sealed 12" with a linkwitz transform would work. Any budget restrictions?

[bbggg]

Originally Posted by theJman

deciphering all the information contained within the TS parameters

If you are to comprehend the issue in depth, you will need a background in Physics: namely simple harmonic oscillation, damped harmonic oscillation, and driven, or forced, harmonic oscillation. Once you have the math equations for these down pat, it will be smooth sailing from then on. When it comes to tuning sealed boxes, the basic math is easy to do with pencil and paper - no need to resort to simulation software unless more sophisticated parameters are being investigated.

[theJman]

Originally Posted by TundraLTD

if you have only 13-14" cube to work with a sealed 12" with a linkwitz transform would work. Any budget restrictions?

The skys the limit! Or $500. Whichever comes first...

[theJman]

Originally Posted by bbggg

If you are to comprehend the issue in depth, you will need a background in Physics: namely simple harmonic oscillation, damped harmonic oscillation, and driven, or forced, harmonic oscillation. Once you have the math equations for these down pat, it will be smooth sailing from then on. When it comes to tuning sealed boxes, the basic math is easy to do with pencil and paper - no need to resort to simulation software unless more sophisticated parameters are being investigated.

Surely it can't be that hard. How are others doing it then? If you can't make heads or tails of the TS parameters without intimate knowledge of physics it seems logical to assume very few people would be able to make DIY speakers. At some point knowing what to look for in a driver -- spec's wise -- has to factor into the plans, so in that regard everyone (or virtually everyone, anyway) who makes a speaker would have to possess some ability to understand the parameters.

[sreten]

Dayton Audio T1003K 10" Titanic Mk III Subwoofer Kit

Hi,

just start looking at good subs near what you want. Typical parameters
will start jumping out at you. For what you want sealed is the way to go.

So you want a 10" driver and a 14"x14"x14" box. No problem.

Cost ... what basically happens as you pay more the driver becomes less
efficient, requiring a bigger amplifier, but as its less efficient it goes lower,
and generally the driver excursion capability increases - this determines
maximum volume as long as you have enough driving power.

Your other option is a low Qts 10" driver with a PR in that box volume.

Parameters are quite different to sealed.

e.g. Peerless XLS10 10" Subwoofer (830452) and Passive Radiator (830481)

rgds, sreten.