The Dave's Fi IB Quad 18" Build Thread

[Avus_M3]

Some of you might have remembered my dual 18" Sound Splinter RL-P LLT build thread as seen here. Well, I sold the RL's and just bought/received 4 Fi IB 18's! BTW Thanks Scott!

Something about 2400 watts and 29 liters of displacement just drew me in. Anyways, as promised I am starting a new build thread. I already bought the wood, primer, glue, paint, etc., basically all the supplies I need. I should start actual construction Monday.

[Avus_M3]

Here's a quick rundown:

4 Fi IB 18's powered by a Crown Audio CE4000. The room is 21' X 15' X ~14' (averaged -vaulted ceiling). Currently, we set the Pio 6010 in the middle of the wall lengthwise (until I figure out how to mount it in the rock fireplace).

The manifold will be located dead center above the TV about 12 ft high. The rear of the room (right of the TV and manifold) is non-existent. It is fully open to the kitchen and breakfast nook. I don't have any EQ of high pass yet and won't until I run a few sweeps.

[Avus_M3]

Here are some pics of the room when we moved in a short while ago:

[Avus_M3]

Here's the manifold design. Some might say it is overkill but what is 4 18's with 2400 watts?? The drivers will face in and be mounted from the inside for a flushed look.

[Avus_M3]

[Avus_M3]

Here is what I have modeled so far using 2400w and 550 cu ft (~15,500L) which is what I have for the rear space and satisfies the 10X Vas suggestion.

SPL






Group Delay






Cone Excursion

[Avus_M3]

Some Woofer pron

[Avus_M3]

[Avus_M3]

BTW for those who ask about the plywood under the Pio...it's temporary because I am scared about setting in on the glass.

[atledreier]

I'm DEFINETLY following this thread!

[Mike P.]

That's a lot of woffage! It will ne interesting to hear your impression of the IB compared to the LLT since you've had both.

[bonehead848]

is that a car audio sub you have been using? HAHA, people are going to think a bomb is going off in your house.

I may have missed it but what amp are you planning on using?

[Avus_M3]

Mike P. wrote:

That's a lot of woffage! It will ne interesting to hear your impression of the IB compared to the LLT since you've had both.

The LLT never got built. I bought the plasma and am going to setup the room a little different so dual LLT's would not fit in the picture.

bonehead848 wrote:

is that a car audio sub you have been using? HAHA, people are going to think a bomb is going off in your house.

I may have missed it but what amp are you planning on using?

The car subs are from my wifes car and are just temporary to make sure the amp, receiver, etc are good to go. As for the amp I listed the monster above. It's a Crown CE4000.

[Avus_M3]

Well, unfortunately I won’t have time to cut today. Maybe it will happen Thursday. Anyways, the other day I noticed an error in my measurements and fixed that. I also finished the cut sheet this morning. I have included pics of both.

Last Revision:


Cut Sheet:

[Avus_M3]

My tools to to measure things out REW, Behringer UCA202, and a Galaxy CM140 SPL mic.

The Behringer:


Behringer Response:


The Galaxy:

GOOD GRIEF! I'll have to agree with

Sweet!

my wife would get very upset I think

[Owen Bartley]

Dave, you've got some serious displacement ready there! And thanks for all the pics by the way. You've got a big room, but I don't think you'll have any problems filling it. So where is the manifold going to be mounted?

PS, if that glass is tempered you should be fine! Was there a rating that came with the stand that will tell you how much it can hold?

[Avus_M3]

hotrodf1 wrote:

GOOD GRIEF! I'll have to agree with

Sweet!

my wife would get very upset I think

Hehe...my wife ust shakes her head. Give me a few days and her whole body will shake!

Owen Bartley wrote:

Dave, you've got some serious displacement ready there! And thanks for all the pics by the way. You've got a big room, but I don't think you'll have any problems filling it. So where is the manifold going to be mounted?

PS, if that glass is tempered you should be fine! Was there a rating that came with the stand that will tell you how much it can hold?

Yes it is tempered and supposedly will cover the weight of the Pio but it's just temporary until I mount it. There was a thread actually on AVSForums where a members Panny shot through his tempered glass stand sending glass shards everywhere. Don't want any of that action. If there is even a small flaw in tempered glass it dramatically reduces it's strength. Other than that tempered is REALLY strong.

[Fi Audio]

Cant wait to see this one up and running

Thanks,
Scott

[Avus_M3]

...it's not going to be an issue if my opening is 2,980.64 sq cm is it? My opening is 11" by 42". The drivers total about 4900 sq cm. I could add 2" to the height or increase the width by 1.5" if needed. Thoughts? I am looking to make the cuts tomorrow hopefully.

[Avus_M3]

Well it's been raining since late Wednesday night/Thursday morning..GO FIGURE. No wood cutting for me since I have to drive them to my friends house to use his table saw and router

On a side note I did some in room testing at it looks like I am facing a few issues. I have a BIG room mode I need to work around. It's a big dip around 59hz. I also have a dip around 11.5 hz, and a dip around ~47hz.

I also noticed that there is a big rising from about 7 - 8 hz and down. Is this an issue with the Galaxy cal file or is room gain that significant that low?

[MatrixDweller]

This infinite baffle stuff is taking this hobby to a whole new level.

What do your neighbours think when you crank things up?

How well do your other speakers keep up?

[bonehead848]

MatrixDweller wrote:

This infinite baffle stuff is taking this hobby to a whole new level.

What do your neighbours think when you crank things up?

How well do your other speakers keep up?

I do not have an ib but i have heard that because of the way an ib works it does not get really loud outside the house. I remember reading one persons description of their ib setup on the cult being much quiter outside the house than their older ported setup.

[hifiger]

If you plan to run your IB higher up, >20hz at max pressure levels, you may notice some chuffing--and burning of VC's , but if you stay with a lower tuning (EQ) instead, ~10hz, you will likely hear less if any chuffing. This is based on the assumption that chuffing is due to airspeed, and airspeed decreases with frequency reproduced, and increases with amplitude. Personally I would not worry. If you had a Sonosub that could have that much radiating surface area (port and driver) you wouldn't be worried would you? If you are truly looking to get the best advice for the SD vs manifold opening size question, you should make a visit over to the IB Cult forum and talk with ThomasW, Chrisbee and the guys over there. .02c

Edit: and good luck with your project. The last guy who made a quad Q18 IB had to switch to large sealed cause his house was vibrating to vigorously. He had installed the manifold in a wall to an adjacent room, and the backwave was too much for him.

By the way, is your planned backwave area an attic space?

[v1rtu0s1ty]

Avus_M3 wrote:

Well it's been raining since late Wednesday night/Thursday morning..GO FIGURE. No wood cutting for me since I have to drive them to my friends house to use his table saw and router

On a side note I did some in room testing at it looks like I am facing a few issues. I have a BIG room mode I need to work around. It's a big dip around 59hz. I also have a dip around 11.5 hz, and a dip around ~47hz.

I also noticed that there is a big rising from about 7 - 8 hz and down. Is this an issue with the Galaxy cal file or is room gain that significant that low?

Glad yours is almost done. I haven't installed mine yet. I don't have the theater yet. By the way, does dip mean drop?

Look at my room response too since I don't have any walls yet in the basement.

http://restricted.dyndns.org/qscamp/...a_REW_Tool.jpg