D130F Alway room for Improvement

[Zilch]

Lemme check again.

*click*

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BB6P suggested HiFi (maximally flat) alignment for D130, black:

2.372 cuft gross
2.035 cuft net of driver and ports

56.95 Hz tuning
F3 = 89.46 Hz

2 x 4" port
5.52" long

OR,
2 x 3" port
2.213" long
2.302 cuft gross

With heavy fill (advised, probably, red)
56.33 Hz
F3 = 91.58 Hz
2 x 3" port
1.751" long
2.298 cuft gross

Cursor's at -10.05 dB

Build a test box and try it before committing.

24" H x 18" W x 12" D, 0.75" stock.

[I am but marginally competent at this. If the results are good, it was BB6P that did it.... ]

[GeneT]

Yes, what Zilch said:

The money you'll spend on POS 075/2402s will buy you a pair of JBL's TOTL Be-diaphragm compression drivers, 2435HPL, used. An additional $200 will get you a pair of new JBL PT waveguides to mount them on. Make small (2.4 cuft) mid/high boxes tuned properly to stack on subs.

I did take a gander at the wave guide info so once again I was off doing homework. Zilch you're suggesting two way system with a wide frequency horn driver. It seems almost incredible that a single horn would cover enough of the mid and treble ranges. I probably missed it but what frequency were you using to crossover to the horn and would you have any suggestions for obtaining crossovers.

On the port dimensions for the box..
2 x 4" port <---should this be 1 x 4"
5.52" long 5.52" long ?

OR,
2 x 3" port
2.213" long

If I do decide to build these they won't be setting on B380 subs. Not that I have anything against them but money is an object and based on many feedbacks I've read I'd feel comfortable buying the Hsu VTF3-MK2 ($559.00 on sale), or possibly the VTF3-MK3 (699.00 New model with significantly more output, upgradable and Dr. Hsu's preference). I can't imagine needing two of either of them for my circumstances. I thought about going even less to the STF-3 but per the responce from Dr. Hsu,(http://www.hsuresearch.com), the suggested compromise was the VTF3 Mk2.

"The STF-3 does not plum the depths, so Pulse would not sound very impressive and you will not take advantage of the 16 Hz standing wave of your room. I would suggest stretching to the VTF-3 MK2 which allow you to add the turbo at a later stage to improve the low bass capabilities." He also suggested a low freq crossover of 80Hz which can be actively handled by the Onkyo TX-SR800 (feeding the HK730 as the Power amp).

I don't have BaseBox6 but I did a few years back play a little with PerfectBox 4.5 and today I downloaded Unibox. I thought I'd try running those and see how they matched up wit the curve you generated. Thanks for all the info. Gene

[Zilch]

It's 2 x 4" ports OR 2 x 3" ports of the specified lengths.

I'm active crossed (M553, with subs) at 1.0 or 1.2 kHz, depending on which waveguide type. VHF rolls off above 18 kHz.

http://audioheritage.org/vbulletin/s...389#post147389

You'll likely want to use PT-F in your small boxes.

You can build two B380s for the cost you're quoting for one HSU, and have enough left over to buy an amp to drive them....

[GeneT]

Well That's interesting. I took a quick look for references to the 380's and at first blush they looked expensive. I must have been looking in the wrong places. The AV cabinet is about peaked out so it's an advantage not to deal with another amp (there)..but maybe I can put a lift kit on the sofa and start hiding them. - Gene

[Zilch]

At the end of this article:

http://www.lansingheritage.org/html/.../1983-subs.htm

Here's a pic of one (rear) built by forum member Hamilton. It's 2235H in a 4.5 cuft ported box:

http://audioheritage.org/vbulletin/s...907&#post82907

[GeneT]

Zilch

Know anyone that want's to sell some 2435HPL's. They don't seem to be in plentiful supply (or any supply) used, so far, though I can buy new replacement diaphrams for $756.00 each.

Also when I asked about port dimensions I was thinking vent, not port. My mistake.

Gene

[Zilch]

You have to put 2435s on your "Favorite Searches" list at eBay.

They are occasionally listed as low as $199.99:

http://audioheritage.org/vbulletin/s...ad.php?t=14935

Build your test box while you're waiting, and see if you like the midbass and midrange sound of D130 in it....

[johnaec]

If anybody wants to try PT-H95 horns, (90x50), with their 2435's, I've got a pair in mint condition I'll let go for $75, (less that half retail). I got them not realizing I couldn't use my 2447 1.5" drivers on them, but 2435's will mount right up.

John