TL_A&B

[dbaudio]

Hey yall, I just finished TL B, except wood finish, sorry to say things did not come out as expected.
Started with idea that an 8" fr driver would supply enough bass extension, so looking at whats out there - Nirvana 8, Fostex 8, new Dayton ps220-8. Bought the Dayton and got no less than F3=150 hz. TL A is a 64" staight line, 48 in2, 1.7 cf, 22oz polyester. TL B is an 9" offset straight line with the same dimensions, which I thought would improve the situation... still F3=150hz.
Parts Express, Dayton ps220-8 specs using WT I = Fs 44, Qt .37, Qe .39,
Qm 5.3, Vas 2.2 cf, Sd 220cm2, re 6.3, le .65, 96db, BL 7.2 Tm.
Any Suggestions?
PS: I have tried and tried to convert bmps, to show a couple attachments,
couldn't figure it out- too big?

[Bob Brines]

First suggestion-- convert those bmps to jpgs and you will have a lot better chance of loading.

Second -- Those three drivers require vastly different boxes. You do not mention the size of the open end. I'm guessing that it is the same area as the rest of the pipe and, yes, F3=150 sounds about right. Also 9" offset is way too little to have any real effect. But that effect has nothing to do with the tuning frequency, only reducing unwanted harmonics. you need to do some modeling if you want to get it right. the preferred software is HERE. Read the documentation there to get a handle on what the physics are with quarter-wave pipes.

Bob

[GM]

'BIB' pipe horn for low, medium Qt drivers. That, or add a BSC ckt. to the existing ones to trade some efficiency for a proper tonal balance if its size and/or lack of suitable placement makes it not an option.

Dunno, when I convert them to 'gif I've so far been able to post them.

GM

[GM]

Originally Posted by Bob Brines

First suggestion-- convert those bmps to jpgs and you will have a lot better chance of loading.

FWIW, when I was having problems with this issue, Dave p10 posted that .gifs was the best choice for at least these forums and maybe on-line period [I can't remember now], but it has so far worked for me.

Not sure if it's typical, but the one 369 kb bmp example I've kept converted to a somewhat larger, 'whiter' displayed 832 kb jpeg/42 kb gif.

GM

[rjbond3rd]

Hi guys,

GIF is best for graphs because it compresses large blocks of repeating pixels. But it can't handle many colors simultaneously. It's limited to an "indexed palette." JPG is good for photos but sometimes it can make a graph with lots of solid white look a little gray or pinkish, in which case GIF is better.

[Bob Brines]

Play with this free program. For jpg's, set the max file size to 80k. Even at 800x600, the pictures will look fine on the internet and they will load in a flash.

Bob

[dbaudio]

Thanks Bob Brines for your info, the terminus for both are 6"x7". I read somewhere that
the chambered line has the lowest F3. I have read up on the Martin site, also the Augspurger tables. I leaned more toward the latter which calc'd F3 of ~70 but with a 3.3cf line. This would mean a box 2x my size (24" deep),
so goes the saying " T-Lines require a large box for bass extension ". Looks like with hind site I end up using a subwoofer for bass extension.

[dbaudio]

Finally was able to shrink these docs using Zip.
Gives you better idea of my TL a&b builds. Also note, although probably not as clean of sound; the linear bass extension for the Vented Box shown would work too.

[Bob Brines]

Your driver in my MLTL:

40"x9.5"x10.5"
Driver 10" down
Port 4"x6" 35" down.

F3~40Hz, F10~30Hz

Bob

[GM]

Greets!

Originally Posted by rjbond3rd

GIF is best for graphs........

Thanks! Yeah, found my notes, this is basically what Dave told me.

Originally Posted by Bob Brines

Play with this..........

Thanks for the reminder, I've had this program for ages, but keep forgetting about it.

GM