IB Opportunity

[dkalsi]

We are partially renovating our basement (after a recent flood) and will be replacing the lower half of all drywall in the entire basement.

I never thought about and IB install before, but have an opportunity to do something now.

I'm not a basshead or anything but can appreciate nice low end response.

We don't have a dedicated home theater per se, but we do have a projector setup and very decent DIY HT sub (JBL W15GTI tuned to 16hz).

When I was determining where to place my current sub, I employed both the "subwoofer crawl" method and RoomEQ Wizard Measurement method. So, at my current listening position, the subwoofer is at its best location. Turns out, that is also happens to be the only place where I can install an IB if I wanted to go that route.

The back side of that wall is enormous storage space (probably 33' x 24' x 8'). This space is currently my woodworking area.

Materials I on hand: a pair of Dayton Audio IB385-8, MiniDSP Balanced, and QSC Plx 3402 amplifier

Something I can consider buying: Fi Car IB318v2 (pair).

I'm really happy with my current sub and don't feel like I'm missing out on anything. The JBL W15GTI is a pretty capable driver and its being powered by a BASH500S amp. I don't think I ever push it anywhere close to its full potential. So I'm curious if there is anything for me to gain.

Additionally, as I was trying to play with WinISD and IB318 - it seems like as I continue to increase the rear volume, the outputs starts to decrease. Maybe I'm missing something, I though the rear volume could be as infinitely large as I want?

Lastly, based on modeling on the Dayon IB385 woofers I have on hand, seems like they will run out of excursion at 35hz if powered to max level. And the output at max power is only 1-2db higher than my current sub - with the delta increasing for from 16hz down to 10hz.

Any input would be much appreciated.

[ThomasW]

Hi,

Trying to draw significant conclusions from a WinISD model of a IB sub is a little pointless. WinISD is not intended to model 'infinitely' large spaces and it doesn't take into account the idea of room gain. So it won't tell you much when trying to split hairs comparing driver performance.

We have dozens and dozens of IB's built with the Fi drivers. If your room is a standard rectangle with the IB in the front you'll get great performance from the Fi drivers.

You might post a pic or drawing of the room and proposed placement of the IB. Then we can discuss whether or not your plan is a good idea.

Regards,
Thomas

[wwhlimi]

When I modeled my setup, I ignored the output as it won’t be indicative of real world output. I modeled to determine power requirements and at what power the drivers would be limited by excursion.
The 15” woofers listed aren’t a good choice as they’re 14mm one way excursion and based on that and the surface area, you won’t displace much air.
The Fi Car 18s have been used a lot and Vd will be much higher.
Read all the FAQs. Wealth of info there.
I’ve had my IB for about a month and a half and I will never go back to regular “box” subs.
Good luck with the build.

[dkalsi]

Aug 16, 2018 17:34:43 GMT -7 ThomasW said:

Hi,

Trying to draw significant conclusions from a WinISD model of a IB sub is a little pointless. WinISD is not intended to model 'infinitely' large spaces and it doesn't take into account the idea of room gain. So it won't tell you much when trying to split hairs comparing driver performance.

We have dozens and dozens of IB's built with the Fi drivers. If your room is a standard rectangle with the IB in the front you'll get great performance from the Fi drivers.

You might post a pic or drawing of the room and proposed placement of the IB. Then we can discuss whether or not your plan is a good idea.

Regards,
Thomas

Thomas,

Sincere thanks for responding. See room layout below:

[ThomasW]

Thanks makes things much more clear.

That should be fine. Plan on making some 'super chunk' bass traps for the rear corners of the room to flatten the response

[mtbdudex]

Since this is a basement the ceiling is NOT drop tiles in a grid, rather drywall correct?

Just making sure the backwave won't leak into your listening space.