# 4thtry's combo InDIYana/Iron Driver build
**URL:** https://discourse.midwestaudio.club/t/4thtrys-combo-indiyana-iron-driver-build/849
**Category:** DIY
**Tags:** passive-xover, bookshelf, 3-way
**Created:** [October 23, 2026, 10:16pm UTC](https://discourse.midwestaudio.club/t/4thtrys-combo-indiyana-iron-driver-build/849 "2026-10-23T22:16:43Z")
**Posts on this page:** 7
**Page:** 1
### Author:  [@4thtry](https://discourse.midwestaudio.club/u/4thtry)
#### Post date: [October 23, 2026, 10:16pm UTC](https://discourse.midwestaudio.club/t/4thtrys-combo-indiyana-iron-driver-build/849/1 "2026-10-23T22:16:43Z")
I’m going to attempt a combo build. Not sure if I’ll be able to attend both events, but this way I’ll be ready for both, just in case.
Current driver retail prices:
**• SB13PFCR25-4 woofers: 37x2=74**
**• SB19ST-C000-4 3/4" tweeter: 24.5x2=49**
**• PC83-8 3" full range mid: 16x2=32**
**• Total: $155**
**Target xovers:** 700Hz and 3kHz, 4th order; totally passive for Indy; active for Iron Driver. Think I’ll do the active xover first, even though the event will be later. This way I can dial in the sound before ordering parts.
**Woofer alignment: 0.5 to 0.55 cu.ft. box tuned to 45Hz. 2"ID x6.8"L port.**
**Handi-panel:** A single thickness 3/4" handi-panel would create a box with an approximate internal volume of about 0.93 cu.ft. Internal volume will therefore need to be cut in half by doubling up the wall thickness as necessary until the entire handi-panel is used up. This will make for a very heavy, dead cabinet with an approximate wall thickness of 1.5" on most panels.
**Sides: 15 x 15 x 0.75" (2)**
**Top/bot: 6.5 x 15 x 0.75" (2)**
**Baffle/back: 8 x 15 x 0.75" (2)**
The total internal volume will be 6.5\*13.5\*13.5 = 1184 cubic inches or 0.68 cu.ft. This is intentionally oversized to compensate for the required scrap usage. By my calculations, the above 6 panels will use 77% of one handipanel. 23% will be therefore be offcut scrap material, which equates to a volume of 198 cubic inches.
So, if I glue all the scrap material inside the cabinet, the net volume will be 1184-198 = 986 cubic inches. 986/1728 = 0.57 cu. ft. The driver magnets will reduce the internal volume a little bit more and I will also need to glue the driver cutouts inside the box, so the net volume should come out to roughly 0.50 cu. ft when all is said and done. More to come.
Alignment with 0.5 ohms series resistance:
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### Author:  [@4thtry](https://discourse.midwestaudio.club/u/4thtry)
#### Post date: [October 24, 2026, 2:50am UTC](https://discourse.midwestaudio.club/t/4thtrys-combo-indiyana-iron-driver-build/849/2 "2026-10-24T02:50:35Z")
The midrange PC83-8 driver will get a small 70 cubic inch sealed enclosure, stuffed with a small handful of denim. This sub enclosure will also help to reduce the overall woofer internal volume, getting it closer to my target of 0.50 cu. ft. QTC for the mid enclosure will be about .96 with a small 1dB bump up in the 150-300Hz region.
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### Author:  [@DrewsBrews](https://discourse.midwestaudio.club/u/DrewsBrews)
#### Post date: [October 24, 2026, 1:03pm UTC](https://discourse.midwestaudio.club/t/4thtrys-combo-indiyana-iron-driver-build/849/3 "2026-10-24T13:03:37Z")
Making the midrange enclosure out of the board? That was discussed in the theme challenge thread.. and seems like it would be required to construct the mid cup from the board material. Which is why i decided to go 2-way instead of 3.
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### Author:  [@4thtry](https://discourse.midwestaudio.club/u/4thtry)
#### Post date: [October 24, 2026, 3:26pm UTC](https://discourse.midwestaudio.club/t/4thtrys-combo-indiyana-iron-driver-build/849/4 "2026-10-24T15:26:25Z")
> [@DrewsBrews](#):
>
> Making the midrange enclosure out of the board?
Yes. After cutting the 6 panels, there will be one fairly large scrap piece left over that is more than big enough for the midrange sub-enclosure.
What I am discovering is that you need to make the internal volume slightly oversized, then fill it in to meet your target with the scrap material. Then you will have enough volume to do whatever your targets require. Some of this is guess work, some of it is based on layout, but I plan to keep all my scrap material and driver cutouts in a separate box to prevent accidental “non-usage.” When the separate scrap box is empty, the entire 2x4 will be completely used up. 🙂
I’ll put together and attach a 2x4 layout in photoshop showing all of my boards for the 6 sides plus the 3 small boards needed for the mid sub-enclosure.
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### Author:  [@DrewsBrews](https://discourse.midwestaudio.club/u/DrewsBrews)
#### Post date: [October 24, 2026, 6:24pm UTC](https://discourse.midwestaudio.club/t/4thtrys-combo-indiyana-iron-driver-build/849/5 "2026-10-24T18:24:11Z")
OK cool. Wanted to be sure it was accounted for before you got too far into the project. I guess I’d rather risk looking nitpicky than to standby and watch that happen to someone.
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### Author:  [@4thtry](https://discourse.midwestaudio.club/u/4thtry)
#### Post date: [October 24, 2026, 11:34pm UTC](https://discourse.midwestaudio.club/t/4thtrys-combo-indiyana-iron-driver-build/849/6 "2026-10-24T23:34:44Z")
Thanks for the heads up, Drew. Much appreciated. I think I am OK, but I’ll double check my numbers just to be sure. 👍
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### Author:  [@4thtry](https://discourse.midwestaudio.club/u/4thtry)
#### Post date: [October 25, 2026, 3:33am UTC](https://discourse.midwestaudio.club/t/4thtrys-combo-indiyana-iron-driver-build/849/7 "2026-10-25T03:33:39Z")
Here is my handipanel cutting plan. Let me know if you see any errors. The plan includes 1/8" kerf losses and the three panels for the midrange enclosure.
