Center to match 120Ti

[briang]

Now that my DVD-A 5.1 collection is growing, I'm pondering a DIY Center.

I'm thinking of using the following:

1-044Ti Tweeter
1-104H Midrange
2-116H-3 8” Woofers (likely in parallel, but maybe in series).

In my current vision, the tweeter and mid would be center mounted on the baffle with the tweeter above the mid; the woofers would then flank them on the right and left. Cabinet will likey have separate chambers for each woofer and be front ported.

Crossover would model the rest of the TI line.

Anyone have input on this idea? Anyone tried it yet?

[opimax]

Brian and i spoke briefly about a center channel for TI series. I also have a 44ti, 104 for upper. I was going to use 2 108 instead of the 116s. XO was ?? and Box size is ???? . I think either of these choices should be a decent match.

I would think/guess the 104 should have a small chamber in the box for itself, the 44 should be all right without but does it need any baffling consideration the way 44 is angled on the 250? it isn't on the 120s.

how does the woofer set up work? both get the same signal or is one crossed lower than the other?

Were you thinking that the box would look like a ec35 give or take?

I wish I had answers more than questions...

Mark

[Zilch]

I'm measuring some 116H-3s this weekend. Never found the T/S parameters for them. I'm wondering if they might be suitable for closed-box, i.e., a reversion.

[briang]

I'm measuring some 116H-3s this weekend. Never found the T/S parameters for them. I'm wondering if they might be suitable for closed-box, i.e., a reversion.

Awesome news, Zilch!

I look forward to your analysis.

[Zilch]

116H-3, sample of one, courtesy Johnaec:

Revc = 4.38 Ohms
Fs = 36.65 Hz
Qes = 0.48
Qms = 7.74
Qts = 0.42
Le = 0.39

EBP = 82

Compare to the rest of the "Family" here:

http://audioheritage.org/vbulletin/s...30&postcount=3

Not the throwback to decidedly closed-box preference I had hoped for, they're intermediate between closed vs. ported alignment drivers, i.e., they'll swing either way. Like H-1, they'll play with excellent bass tonality in acoustic suspension, just not with the extended-bass reach of the originals.

That's how I'd use them, having experienced the special pleasures of that alignment building Minis....

[briang]

116H-3, sample of one, courtesy Johnaec:

Revc = 4.38 Ohms
Fs = 36.65 Hz
Qes = 0.48
Qms = 7.74
Qts = 0.42
Le = 0.39

EBP = 82

Compare to the rest of the "Family" here:

http://audioheritage.org/vbulletin/s...30&postcount=3

Not the throwback to decidedly closed-box preference I had hoped for, they're intermediate between closed vs. ported alignment drivers, i.e., they'll swing either way. Like H-1, they'll play with excellent bass tonality in acoustic suspension, just not with the extended-bass reach of the originals.

That's how I'd use them, having experienced the special pleasures of that alignment building Minis....

Acoustic Suspension would simplify the box building. Zilch, do you have any recommendations on box volume for each woofer?

[Zilch]

BB6P says 1.3 cuft for similar 116H-1. We used about half that for the Minis.

For two in the same box, it says 1.25 cuft per driver, 2.5 cuft total.

Closed-box designs are very forgiving with respect to box volume.

For true acoustic suspension, it shoud be 1/3 Vas or less, which for H-1 would be 0.57 cuft net, 0.61 gross internal volume for each driver.

Use heavy fill....

[opimax]

Brian and Zilch,

I realize this your thread but is there any info using 108s instead?

thanks

Mark

[Zilch]

It's not in the BB6P database, so start with the T/S parameters.

EPB = Fs/Qes.

Closed box = <50

Vented box = >100

[opimax]

Zilch ,

If that info is for me (1st thanks!!) then I will have to show how little I really know about this stuff and say

Vented>100 , 100 what, volume size? cu inches?

For my car stereo Sub woofers I have decided over the years I like closed boxes but this isn't a sub and i am trying to match the 250 which are vented so i would think vented here? on the other hand I have some weight restictions so closed might be better since it is smaller. In the 250 there is a small internal sealed box for the 108s but I wish to go lower than the original?? I don't know if timbre matching will matter on the box design and should i be worried about a XO yet?

Mark

[briang]

Brian and i spoke briefly about a center channel for TI series. I also have a 44ti, 104 for upper. I was going to use 2 108 instead of the 116s. XO was ?? and Box size is ???? . I think either of these choices should be a decent match.

Looks like a box size of ~2.5Cu Ft.

I would think/guess the 104 should have a small chamber in the box for itself, the 44 should be all right without but does it need any baffling consideration the way 44 is angled on the 250? it isn't on the 120s.

I was thinking that I have a pair of LE5-12 chambers from a pair of parted out (not by me) L150A that will work for the 104H. Or I could just box the 104H in a subchamber of similar volume within the box.

how does the woofer set up work? both get the same signal or is one crossed lower than the other?{

I plan to run them in the same range (same signal).

Were you thinking that the box would look like a ec35 give or take?

Yep, similar to the ec35.

I wish I had answers more than questions...

Mark

No problem.

[Zilch]

Closed Box <50 EBP 100< Vented Box

You need T/S parameters to design a box.

Otherwise, build test box(s) and evaluate the performance.

[OR, just do what Giskard says to, if he does (or did).... ]

[opimax]

Zilch,

Still don't understand the EPB.

I had asked Giskard and have not heard from him (yet?) about this. I did hear he was not thrilled about using the 115-1 from the 20t-20t3 and 18ti. that was when I decided to go for the 108s.

I don't know if the 108 will go low enough in this application, hoping 2 should make it though. when I get home and if I have some time to myself I will search for parameters for the 108 unless you know I am wasting my time.

I think Guido said he would build me a xo if I wanted to buy 1 that would work. It would be fun to do this myself if i can .I have the original 250ti XO not being used I could work with. or buy 1 of the ones he used to build my current XO and get that modified to match.

In a perfect world I would build this very meticulously from a kit 1 could buy. That I can do...

[Zilch]

Still don't understand the EPB.

I provided the formula for EBP, Fs/Qes.

[Robh3606]

Look here for T/S on the 108H

http://audioheritage.csdco.com/vbull...highlight=108h


Rob