Tips/Assistance building new sub box!!

[ryz]

Hey guys, just signed up cause it looks like you guys are all switched on and know what your talking about!!

I am wanting to build a new sub box for my Logitech z5500's, which i beleive is a TangBand WT-644F driver. I have read around a fair amount of info about what I need to do, and how to calculate stuff, but I have run into some problems, and am getting differing results from different programs as to how big the actual box should be etc. and am just getting stuck and am no longer confident.

I have access to all the tools etc. I require to do basically anything associated with making it up, but yeah, just basically need a hand.....

p.s. I am not really that knowledgable when it comes to Qts and Sd's etc. etc. but I think I can follow along. been through a number of threads on here, and I think I was hanging in there....either that or just completely confused!!!

Thanks guys!!!!

[4pyros]

Post what you what for a box and what you have done so far.

[ryz]

im not sure what type of box i want, at this stage i like the ported system (cause it looks easier, the transmission line system, and i really like the idea of the driver being hidden in a 4th order bandpass system (but not sure if that affects the sound itself, and also its a 10'' driver so might make the box too big?

its for a bedroom, so not sure if that makes any difference, and im more or less making it just to keep me busy , but i want to make it right so that it actually does its job. Im not in the know at all unfortunately, just know how to use tools haha.

And i havnt done much at this point, just alot of calculations which has given me box volume calculations of:

62.54litres, 61.5l, 52.88l, 50.54l, 41.38l (which is closest to the current, stock box design vol) and a random one at 99.2l (Note: all these are for ported systems)

I got all of these figures using random calculators on the net, and calculating T/S values through how to guides etc. on the net also.

http://www.tb-speaker.com/detail/1208_03/wt-644f.htm is what i believe is the speaker, sourced other info from enclosure for TB WT-644F (z-5500) 10" as well as other sources.

I guess i have over complicated it by doing too many calculations etc, so now i have no idea where i should be looking. im thinking around the 56-58l area?

also any tips on adding bits to the box would be great.

p.s. some calcs i have on hand are...Qes(d)=.370, Qms=10.14, Re=6.4ohms, Fs=32Hz, Le=4.54mH, Dia=24.6cm, Xmax=10mm....which i think means, Sd=0.0475m^2, Vd=0.0005m^3, CMS=.24mm/N, mmd=103.1g, BL=18.9Tm, RMS=2kg/s, Qes=0.37, Qts=0.357, Eff=90.2, Sens=91.1

these above value are based on 77l, and dont ask me what most of the letters mean! i have no idea

[chris661]

Okay, a low Qts (~0.3) indicates you'll get more bass extension from a ported box.

I'd try modelling a ~60L cabinet tuned to 29Hz (pulling numbers out of the air here), see how that looks on winISD.

You're looking for a reasonably flat response to ~30Hz (the driver could go lower, but would require a specialised cabinet), then the response will drop.

A bigger cabinet increases output around port tuning (so a really big box will give a peak at 30Hz). Play with port tuning a little (see what 80Hz tuning looks like, see what 15Hz tuning looks like), but I'd expect ~30Hz to be somewhere near.

[ryz]

Originally Posted by chris661

Okay, a low Qts (~0.3) indicates you'll get more bass extension from a ported box.

I'd try modelling a ~60L cabinet tuned to 29Hz (pulling numbers out of the air here), see how that looks on winISD.

You're looking for a reasonably flat response to ~30Hz (the driver could go lower, but would require a specialised cabinet), then the response will drop.

A bigger cabinet increases output around port tuning (so a really big box will give a peak at 30Hz). Play with port tuning a little (see what 80Hz tuning looks like, see what 15Hz tuning looks like), but I'd expect ~30Hz to be somewhere near.

ok, i have winISD pro alpha, if that means anything, and im not super sure how to use it properly. but im struggling to find the values to input it into the new driver section. whenever i click it to save, it brings up a whole list of 'Parameter error list' saying the consistency failed, i dont get much further than that....

also when i exit the program it comes up with an error saying access violation at address?

not sure what ive done wrong....also you mentioned the possibility of a specialized cabinet. how so?

thanks!

[bjorno]

Originally Posted by chris661

..I'd try modelling a ~60L cabinet tuned to 29Hz (pulling numbers out of the air here), see how that looks on winISD.

You're looking for a reasonably flat response to ~30Hz (the driver could go lower, but would require a specialised cabinet)..

Hi,

A specialized cabinet doing the job:

b

[Xoc1]

ok, i have winISD pro alpha, if that means anything, and im not super sure how to use it properly. but im struggling to find the values to input it into the new driver section. whenever i click it to save, it brings up a whole list of 'Parameter error list' saying the consistency failed, i dont get much further than that....

When inputting driver parameters in to WinISD Pro alpha the values have to be exact or they are not accepted - read the help file on how to input the minimal amount of parameters, and let the software calculate the rest. Your driver info should be OK then.

[chris661]

What 'e said. There's a help file that takes you through inputting driver parameters.

Follow it through, and it'll work fine.

Chris

[ryz]

I ended up uninstalling winISD pro alph cause when i went to open the help file it said it wasnt installed on this computer or something, after reinstalling and uninstalling a few times i just d/l winISD 0.44 which i think was a beta version and used that, looks a lot less involved......

what exactly should i be looking for in the results, and should i try and get winISD pro alpha working?

[ryz]

ok wait up, i re-downloaded alpha, and got it to work, without the help file, just left the fields blank and it figured them out for me, although they were pretty much exactly the same as I had entered previously haha :s

ok i've got the graph, chose some 'something butterworth' setup thingy, and this is what i got...


wait... how do i show my results?




wtf why doesnt it work :@