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7,105 Posts
Discussion Starter · #1 ·

I have a very detailed/"real time" multi page build thread at The IB Cult forum , however I want to post here my finished product for the Master Index of DIY Subwoofer Projects thread.

Since my 12 page build thread at the The IB Cult forum requires login/password, I was asked by "LTD02" to post a thread here, this will be "cliff notes" version of that 1+ year journey.

For those considering IB subs:

Read ThomasW IB FAQ a few times http://home.comcast.net/~infinitelybaffled/index.html

Read ThomasW Generic IB design/build/install a few times http://home.comcast.net/~infinitelyb...Bmanifold.html

Many thanks to ThomasW, Chrisbee, and everyone else @ the IB Cult for their help.

The start of my IB journey:

Quite a while ago, sometime in Summer-2007, I read about IB subs, which started my long odyssey into the DIY speaker mindset and attempting to build a subwoofer.

HT room layout:


This is my first DIY speaker project.

At the IB Cult forum I was able to learn/build/create a neat looking (4) x 15" line array IB subwoofer, with fantastic sound capabilities. 12/21/07 was my 1st build thread post and was a 1 year journey.

I've named this IB subwoofer "Usul", because I had to cut thru rock (concrete foundation wall) to make this project a reality, you'll see that below.

I went from thinking about a Dayton HPSA1000-R 1000W Rackmount Subwoofer Amplifier to power 4 Dayton IB385-8 15" IB Subwoofers; to eventually (4) AE IB15's driving them with the Behringer EP2500 Europower Power Amp, EQ Behringer FBQ2496 Feedback Destroyer.

My total investment is around $1.3k, speakers, amp, EQ, mounting boards, hardware, speaker grille cloth, etc.


-I built a 4 x 15" array, it's backwave vents directly into the utility room. That is closed off from the rec room via sealed door. I did more isolation via 1" styrofoam/sealant at HVAC duct locations.

I was concerned about the bass booming the HVAC ducts, since my GeoThermal system is in the utility room and it has sheetmetal HVAC supply/return main lines entering/exiting the room. If there was a duct boom I thought to add some damping method to that problem area. (like a mastic patch to stiffin the duct/etc). That was not needed.

-The array is vertical and on the RH side of my DIY 130" screen. That is due to practical layout.

-My basement is a engineered foundation, the walls are concrete on outside 3-4 " thick, with 2" foam insuation, there are load bearing concretre "studs" 9" deep on 24" centers, these have 3/4" wood attached to them for hanging drywall. My line array baffle plate was mounted to the foundation wall via threaded rod and lag screws. Very solid/rigid, basically 0 in plane motion unlike other line arrays that mount to stud walls.

Planning/cutting the concrete foundation was the 1st major hurdle.

I consulted with Michigan Superior walls and got the information needed to "cut a interior window" in my foundation wall, this was great news, IB array can directly be mounted and the backwave simply radiate into the utility room. Prior I had "wrong/less desirable" ideas.

Since I have a log home, my roof loads are on the front / back walls transferred there via the ceiling/roof beams, not the side (gable) walls.

The foundation wall I'm "cutting a interior window" is on the gable side of my home, just makes things a little easier.

This just shows a lot of thought/planning/design detail has to go into a project before actual construction starts, and during as you run into "unknowns".

Prep area with plastic sheeting to keep concrete dust in control (gosh there was lots of dust, way more than I figured)

16" x 66" IB sub "window", the concrete stud was a royal PIA to remove, my speaker wires were ran thru 3/4" pre-drilled holes on center, so I had to induce cracks there and remove the concrete stud w/o damaging the wires, and remove the rebar rod, 100% success.

Sub-woofer porn shot 4 AE IB15's, now the fun began.

Did the below last year Sat 5/3/08.

Started with detailed baseline of actual existing construction situation on grid/graph paper:

Made a real size paper template, mounted it to see/confirm/modify design.

>>Full size is much better than some scale drwg, gives a real feel for the mounting/other details.

HT side (line array is mounted on this side). I had to cut 1 3/4" slot for the MDF/OSB plate to fit in for mounting on the RH side.

Before drywall, 4 years ago during the framing phase of the basement/HT, I put a 2 x 4 along the concrete joist via construction adhesive and nails, that is my RH side attach point.

That also means the total thickness from inside the HT room will be that 1 1/2" + 1 1/2" for the OSB/MDF sandwich, so 3" step into the HT room side.

View from utility room side, green shows 2 x 4 pressure treated wood I plan on using to "clamp" the OSB/MDF sandwich tightely against the concrete walls/studs AND control in plane stiffness/flex

Cut both MDF and OSB board to 25 1/4 width, glue and lot's of weight. Spread glue.

Weights and constant wiping of the glue that got squeezed out from the sandwich. I found a flat portion of my garage bonus floor, so sandwich OSB/MDF should be flat. Used some scrap 2 x 4 blocking to hold the slippery sandwich together.

Here is my current mtg plate design:

-brown outline is OSB/MDF sandwich

-Dark green (5) horizontal 1 x 2 structural boards for added in-plane stiffness

-light blue are attach on the HT side, I will use bolts to clamp the front of the mtg plate to the 2 x 4's along both sides

-Light green shows (3) pressure treaded 2 x 4's that will be used to "clamp" sandwich board to utility room concrete wall via threaded rods. I will countersink the MDF so the HT side is flush. My idea is the threaded rod will help clamp the board to the concrete studs AND minimize in-plane flex via nut/washer/lockwasher on each side of the OSB/MDF sandwich and on each side of the utility room side pressure treated wood. First, snug up the threaded rod from both outside areas, then tighten both inside areas.

If need be, after watching the sub in action, I could further stiffen in plane motion for the center portion by a center rod, I'm guessing not needed, but don't know at this time.

Next tasks:

-pre-fit mtg plate to area, cut-out 5 clearance notches on RH side for wall stud/wire mtg clearance. Transfer holes/cross bracing locations to both sides of plate, make sure "good to go" and nothing obvious is bad. Take plate to garage, router circles.

Take plate to basement, pre-fit just to check ok.

Take to garage bonus room, cut/glue cross braces on.

7,105 Posts
Discussion Starter · #2 ·
Final in room test, layout on baffle plate.

My first time ever routing circle holes, that Jasper jig works sweet.

I put two scrap 2 x 4's underneath to support the cutout holes - after I did NOT do it for the 1st one....small lesson learned.

Nice day to do this outside, lot's of DUST!

1 hole done, 1 in progress; then all 4 done, I ended up with 3 1/4 inch of board between drivers:

"Cheese" smile from my son, baffle plate mounted, seeing fit situation, everything looks like it should. Now temp mounted one of the AE IB15's.


I know this is corny, but while I was working downstairs after dinner tonight (May 2008) I got this strange urge to name my IB sub-woofer, and this name instantly popped into my head and stuck, so without further delay I'd like to introduce...

(even though the IB sub has not gone thru "birth" just yet, that is 3-ish weeks away or so, still....)

"Usul-the rock of IB subwoofers"

IB Baffle secured to foundation wall via (11) 1/2-13 threaded rod as primary mounting "clamp" and additional (10) 3/8" lag bolts into 2 x 4's on both sides as secondary securing.

Plus, I used (10) 1/4 x 2 1/4 concrete screws to secure the 3/4" wood furing strip that came attached to the concrete studs that hold the 2 x 4's , for added secure/rattle proofing.

Usul is ROCK solid!

The outer (2) threaded rods actually provide the holding force, while the middle one is a support and adjusted to keep the baffle plate flat for speaker mtg (I'm still using 1/2" foam for 100% sure seal).

On the baffle side I use a self-locking hex nut and big washer to distribute load, the other 3 interface used big washer/lock washer/hex nut.

I counter-sunk the front nuts so veneer is still possible.

I should say I kicked Usul, screamed at Usul, and still he did not break......

Truly the rock of IB subwoofers.

I decided to add (2) threaded rods above the top driver to assure "Usul" is solid, plus I glued a 1 x 2 poplar below the bottom driver for in plane stiffness.

b) sealed the joints from both sides with silicone caulk. The should be zero "leakage", hopefully.

c) cut the side "filler plate" to give the baffle plate a finished look.

The drywall piece I removed 2 months ago will be trimmed skinner width and put back up, it will butt against the side piece.

7,105 Posts
Discussion Starter · #3 ·
Electrical hook up:

a) I plan on hooking up the 4 drivers like this

Re: 5.5ohm

1/5.5 + 1/5.5 = 1/R(e) = 0.3636

R(e) = 2.75 ohm load, so should not overload the amp.


Sunday 6/2/08 2pm - 6pm progress:

Drill/glue and install (12) 3/8 dia "super" magnets:

(polarity marked RED and installed seeing that to make sure same, what a pain to seperate each individual magnetic and then mark-it, but had to be done)

Measure/cut laminate, Contact cement brushed onto baffle plate, be careful drips/sags:

Contact cement brushed onto laminate, use rotating fan to speed up drying of contact cement on laminate to match baffle plate

router AND drywall cutter for "tight" spots, that drywall cutter worked quite well, was able to use it no problem.

So, next steps is drywall cut/install/tape/paint.

Posted 6/30/2008:

I'm no pro drywaller, but my end result looks acceptable. After putting drywall back onto the wall, and feathering of compound to make the two drywall butt edges look decent, painted.

Note for future reference: Tapered drywall edges are much easier to apply compound and make smooth than non tapered butt edged drywall. The laminated manifold looks good enough no edge molding needed, that was my goal.

Being my first time to install drivers, I had some concern of mucking the final "physical part" of the process. Two people are a definite, my wife was in the utility room actually centering/holding each driver while I fixed them with two drywall screws from HT side. I then drilled all holes , and for the locking nut install she was in the HT room while I in utility room.

All the drivers were drilled and locking nuts placed with the gasket removed, then each driver removed and the gasket put back on and finally installed with blue locktite on the thread.

Installing the locking nuts sorta concerned me, I read some stories where people have hard time getting their cap screws to thread after nut install.

I drilled the 1/4" dia clearance hole thru, and then countersunk about 1/4" with 5/16" dia for lock nut, then installing each 2" long cap screw had a few thread sticking out, was able to start the locking nut with my fingers, then my wife tightened them until they bit into the wood. This ensured each locking nut was aligned with each screw, rather then just tapping the locking nut into the countersunk hole without the screw in place.

I should say that a little install method I learned was drill slightly off axis by about 2 degrees away from speaker, this way your drill came out slightly further from the hole edge than where you drilled. Before I did this, on 1st driver I came close to edge on one hole, locking nut still bites, I was lucky.

I read about people epoxying their locking nuts in, I did not need to do that.

When I removed the screws my nuts stayed in place.

Next steps:

Hook up wires/electronics. That is a 2-3 weeks away, I need to first now focus on the non HT basement portion so we can get big carpet install from Lowes.

Finish trimming doors/windows, finish drop ceiling in play/rec room, those "other" minor things in the basement project now need my attention.

Some picts:

Foam sealing gasket in place for each driver, backside of lowest driver:

View from utility room, head shot:

Room shot:

7,105 Posts
Discussion Starter · #4 ·
Posted 7/14/2008:

My EP2500 was bought just a few months ago, and I did confirm the low pass filters were off while the Denon was in manual set-up mode, I could definitely hear and see the difference (cone movement) as I toggled it both positions.

And yes, the DIP sw has the generic Off Left / On Right above it, while the detailed schematic says On Left / off Right is how mine works.

IMO Berringer should remove the generic DIP ON/Off and just leave the schematic there.

Second thing:

That fan is sorta loud, so I'll have to look at the in-line resistor mod I saw linked in the FAQ section. That might be a winter project for me though, not for quite a few months will I worry about that.

Posted 10/28/2008:

Fan Mod time!!

Like many others, I got tired of the "whhooossshhhhhh" of my Berhringer EP2500 amp noise.

I followed Chrisbee's EP2500 fan replacement info as outlined under the amp section on the IB Cult forum.

I used a Newark Part No 31K9990, Manufacturer Part No: FBA08A24L1A cost $9.16, about $15 total with tax and shipping. http://www.newark.com/31K9990/fans-h...uestid=187987/

Axial Fan Current Type: DC Supply Voltage: 24VDC Series: FBA08A

External Height:80mm External Width:80mm External Depth:25.5mm

Fan Flow Rate:24CFM Noise Rating:21dBA Bearing Style:Hydro Wave

Depth:25.5mm Height:80mm RoHS Compliant: Yes

I forgot to measure dBA before the fan mod, but after it was 54dBA 2" from the front and dropped below 50dBA 1 1/2 feet away. What a change!

I recommend anyone with this amp to do this mod, so quiet at the HT seating position now.

I also reversed the fan flow so it "vacuums" air thru the heat sink instead of "blowing" air thru the heat sink. (fan has air directional arrows on it). Finally, I did use real HVAC silver foil tape to improve the air-tightness of the shroud to heatsink to ensure good air "vacuuming" efficeincy of the fan.

Some picts:

Cover taken off, Stock fan in place, hot glue easily cut at fan plug end, unplug. Stock fan on Right, mod fan on left

Mod fan installed, I cut the stock fan and mod fan wires, soldered the ends and wrapped electrical tape. Put HVAC tape for air-tightness seal:

Thx to Chrisbee & others for info on this mod, easily done in 30-ish minutes, and that's with my 3 young kids wanting daddy to explain to them what I'm doing as I'm doing it.

7,105 Posts
Discussion Starter · #5 ·
Posted 1/9/2009:

I'm finally getting carpet in 2 weeks in the Home Theatre, so I've been working on the AV cabinet wiring getting that mess looking better.

I've been intrigued with the cleaner look of the Neutrik Speakon cable ends, and also since I was re-arranging the AV cabinet I got tired of un-plugging the wires/etc.

I bought the NL4FC, studied them, was all ready to hook up my 14/4 ga wires to them (I twist 2 strands together for each + and -, so I'd only be using 2 of the 4 connectors).

Here they are in the EP manual so I'd wire them correctly:

2 parts from PartsExpress:

Well, my 14/4 ga wire twisted 2 each is approx 11ga, too thick to fit into them!!

I was quite dis-appointed.

Guess I should have read their specs more closely before buying, says 12ga:

* Cable: screw-type terminals (crush ferrules provided for use with stranded cable) on 8 pole version or soldering (12 AWG stranded)

* Chassis: flat tabs for FASTON 0.187" x 0.02" (4.8 mm x 0.5 mm) or PCB-version with pins 1.6 mm x 0.5 mm (FASTON is a trademark of AMP Inc.)

To others, save your $'s and don't make same mistake as I did.

Post's dated 1/14/2009 - 1/23/2009 related to my 2nd row seat riser bass trap Q's asked in Ethan Winer's forum:
Home Theatre:Riser/other Broadband bass traps

Posted 1/21/2009:

btw, I was up this morning attempting to use REW to see how my riser modifications into a broadband bass trap worked, I'm still fumbling my way thru REW so nothing to post just today. Maybe later after carpeting is installed.

Posted 1/23/2009:

Finally got REW sorta figured out, was at HTS getting the mechanics of REW down pat.

Now I'll be here posting/plotting the acoustic journey and learning experience, with help/guidance :-*.

Now, going to sleep after taking some measurements, later I'll re-take (after carpeting down) to apply filters.

Here is the IB sub nearfield (2" from cone) & 32" away (I guessed at 1m but was a little close) to see if I've got everything done correct.

(I downloaded the 8000 mic cal file from THS site earlier and used that mic cal file)

Set-up, the FBD is in bypass mode for now, I'm using the Mobile Pre as my soundcard, the internal card in my Dell Laptop D620 gave crappy low freq response compared to the Mobile Pre:

My first REW plot:

Top (brown) is near field, bottom (blue) is 32" away.

Multi plot taken at:

- the 2 near field positions

-4 at 2nd row seating/on the riser.

-2 at 1st row seating

Room modes show themself, I changed the scale 0-200hz since that's all I measured.

Riser broadband bass study, same location, one with the (14) vents open, one closed:

The blue (vent open) is so much smoother than the green (vent closed).

My first waterfalls, was interested if the riser broadband bass helped with delay time or smoother response, looks that way to me.

Vents Open:

Vents closed:

Carpeting is being laid down Monday 1/26, so it will be neat to compare these in general to that.

7,105 Posts
Discussion Starter · #6 ·
Posted 1/24/2009:

Thomas/Chrisbee/others "in the knowledge":

I decided to take some detailed baseline measurements of my IB line array, just to get more practice with REW and learn more about speakers/subwoofers.

Baseline specs:

IB sub line array (4) AE IB15's, EP2500, no EQ, spl 75db calibrated @ 36" from cone.

Can you give me some general comments/critique/etc.

Can I summarize:

Close to "flat" within +- 3db 15hz - 80hz @ 1"?

Room modes are showing themself around 29hz/41hz/47hz etc and will have to be dealt with via further bass traps and/or EQ pushing the peaks down but leaving the lows alone.

Very basic question:

When I decide to apply EQ I take the measurements/75 db spl calibration @ the "main seat spot" (for me 2nd row seat 3) , then use those results to apply EQ filters, and re-take measurements there and elsewhere to confirm changes acceptable or more adj needed, correct?

Line array measured 1" from dust cap for each driver centered:

Line array measured 12" from dust cap for each driver centered:

Overlay of 1" and 12":

Overlay of 1" and 12" with "expanded" to see differences:

Below is the complete 2nd row each seat (4) measured:

The top blue is @ 2" from the cone:

Again, no EQ, just raw sub / room interaction being shown.

Thx for time/advice/education opportunity.

Posted 1/27/2009:
author=chrisbee board=projects thread=957 post=16993 time=1233044684]

Those 2nd row seats have very reasonable curves. You could pull 30Hz down slightly but I doubt you'll notice the difference on programme material. You can probably ignore any subwoofer wiggles very far above the crossover point.

Are you using 1/3 octave smoothing?

The vertical axis on your graphs should ideally be set to the standard of 45-105dB. This makes comparisons easier between different subs. Stretching the vertical axis tends to flatter the curves because it flattens variations. In this case you haven't so much stretched the axis as shifted the window downwards.


I've taken measurement and only used REW at it's default settings, so if I was should apply 1/3 octave smoothing and not default not done, I'll have to go thru it's settings to see.

I swear I did the 45-105 for db axis and 15-200hz for freq axis.

When I opened up REW that was set for one view but not the measure view.

Anyway here is same data just re-plotted:

nearfield plot 1" and 12" from Line array for all 4 drivers:

2nd row seat position, 16'6" from front wall (IB array location) top blue is 1" from line array, this was taken on different day than above graph, close though.:

So I started going thru the menus of REW, settings, nothing about 1/3 smoothing.

Then I found it under graph:

And, I applied that to my 2nd row seats, here they are 1/3 octave smoothed:

They "look" better. Again, no EQ applied yet.

I got carpeting laid down last night, so this weekend I'll take more measurements, and then apply some EQ filters.

Here is the 1" and 12" nearfield re-graph with 1/3 octave weighting.

Posted 1/28/2009:
author=chrisbee board=projects thread=957 post=17005 time=1233097908]

Apart from the gentle hump at 30hz there isn't much to worry about.

You have a nice trend with plenty of output around 30-50Hz where most of the LFE "energy" is. You've been amazingly thorough in your testing. Smoothing can also be applied under "Trace Adjustments" (in the box on left of graph window)

The carpet wont affect the bass but it will make the room much more relaxing to be in because it will reduce the higher frequencies bouncing around. I suppose it is possible that a heavy carpet would help to damp a suspended wooden floor further down the frequency range.

When you start playing with Eq. don't make your filters too narrow or too many. Use a light touch and test after adding new filters. Narrow filters tend to raise the Q of the system and you can't take away what you add in the way of Q. You have a superbly well damped system.

I bet your kids are excited about all the things you have done? Get their curiosity going while they are young and they should stay interested in the world around them. Showing what can be achieved with a little work and imagination teaches them that life isn't just about using credit cards to buy designer labels just to impress others. That's the great thing about IBs. You can't just pick one off the shelf and start bragging. You actually have to put something into it. You've done an excellent job. Nice family too. :'(

Thx for advice Chris and kind words, much appreciated.

I'm a Engineer and knowing baseline/set-up is fundamental 101.

Set 1 filter last night, next post will show my subjective (my ear listening) results.

Yes, you are right, kids are so curious and are watching everything I do.

It's fun to show them what daddy is doing and why, most is over their head but they can grasp lots still.

7,105 Posts
Discussion Starter · #8 ·
Posted 2/3/2009:

Just for fun I opened up REW and re-plotted the 3rd seat chart, this time extending it to as low as REW goes, 2hz.

I thought to myself, am I really-really hearing/feeling sound at such low freq??

Alright, took some picts and made some YouTube videos to prove to people this IB sub does work as low as it can go and does not tear apart.

These AE IB15's are awesome speakers!!!!

Thx Acoustic Elegance guys for superb product.

Test DVD, note the tones are encoded at -20db to "protect the innocent" from destroying their system.

YouTube Videos:

This video show my 4 speaker line array Infinitely Baffled Subwoofer speakers up close, you can see 10hz subwoofer cone movement action .

I'm getting 80db, and this signal was attenuated -20db on the recording, so plenty of low freq headroom. Capable of 100db!!
&fs=1" width="644" height="390">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&fs=1" />[ATTN POSTER: YouTube Insert Error: Something went wrong. Please make sure you added the video correctly. Click here to see how YouTube videos should be embedded. There could also be a technical issue that's not your fault. Click 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" target="_blank">here to view the video on YouTube's site. If this link doesn't work, you did something wrong.]

This video show my 4 speaker line array Infinitely Baffled Subwoofer speakers up close, you can see 3hz subwoofer cone movement action.

Yes, that's not a typo, 3hz. Just an academic study, geeky to see them moving so slow.

&fs=1" width="644" height="390">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&fs=1" />[ATTN POSTER: YouTube Insert Error: Something went wrong. Please make sure you added the video correctly. Click here to see how YouTube videos should be embedded. There could also be a technical issue that's not your fault. Click 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" target="_blank">here to view the video on YouTube's site. If this link doesn't work, you did something wrong.]

Posted 2/12/09:

REW frustrated me for weeks, I was intimidated by it.

The set-up.

The calibration.

The Measurement.

How would a total noob look posting their results vs a seasoned pro?

Printed out FAQ/instructions and read them quite a few times.

I'd try using it too quickly (wanted graphs NOW) and get frustrated, then put my measurement "stuff" away until I got the urge to try again.

Using it does tie all the books we've read into reality.

You read this acoustic book and that, but until you take measurements, think about what they mean, and experiment you are not really learning.

So, I am/was/are partially driven with a passion to learn. Plus maximizing my investment's output for listening pleasure. Read countless threads at here/other forums, saw their posts and their analysis.

I finally said to myself, "take small steps".

-get the sound card calibration down pat (spent a few late evenings)

-get taking measurements down pat (a few more late evenings)

-take baseline readings everywhere, grasp what they mean, and what they don't show - and try and guess why (this was the fun/geeky part, the brain synapse relays kick in here)

-then decide on the filter(s) to apply and one-by-one apply and measure/listen the result.

Don't give up on REW/computers, they are just tools after all.

Us "Men" are still in charge!

My thread is winding down, I've got:

-the grille still to do (put those magnets in the baffle, so I'd better make a grille and use it at least once)

-some wire routing/style points seen in the Utility room

-Achieving the "perfect" blend of EQ via my FBQ2496 and Audyssey MultEQ "marriage" (this will be an ongoing thing, part of the last 2-3% never done tweaker I'm becoming)

Posted 2/12/2009:


BTW, 2 Q's:

1) If you had to specify the "low freq roll off point" for my IB sub what is it?

If I said 5hz is that correct? 6hz? Because there is a 8 to 10db drop there is my reading the chart.

2) How "flat" is my IB sub to?

Again, is 5hz correct? 6hz?

(based upon my 2 - 200hz graph above)

Thx guys.

author=chrisbee board=projects thread=957 post=17312 time=1234476965]

5Hz (-3dB) ?

Posted 2/14/2009:

Looks like anything below 5hz is filtered on my EP2500 anyways, so that is as low as this IB will go....not that I'm complaining.

Therefore, I've added "flat to 5hz" to my sig in all the forums I've posted link to my IB sub build thread.


I changed my sig to "flat to 10hz" after reading about claims of the in-accuracy of the 8000 measurement mic below 10hz, no need for controversy, 10hz is still respectable and worthy for a little bragging.

1,583 Posts
Wow, amazing build thread. I don't know if I would of had the motivation to cut through concrete studs and all that, but more power to you.

7,488 Posts
Congratulations! I didn't get a chance to read everything but I liked all the pictures.

7,105 Posts
Discussion Starter · #11 ·

Originally Posted by CZ Eddie /forum/post/16510100

Congratulations! I didn't get a chance to read everything but I liked all the pictures.

Thx, I now realize the cliff notes version posted here is compressed compared to the 12+ build thread on the IB Cult forum. Hopefully the picts help share what I learned for others to use and break up the text monotony.

There are so many great build threads here.

I learn a lot by reading them and the other "discussions".

2,363 Posts
i need a little more info.


8 Posts

VERY nice room! I figured I needed to thank you
I've had 4 ae ib15s installed in my theater for a few months now and thought they sounded REALLY good... I'm still in the building phase, so no measurements or setup done yet.

Then I came across your thread and saw your wiring diagram posted... and I thought, "mine aren't wired up like that..." So, I ran downstairs to check --sure enough, my 8ohm drivers were wired in series(which would show my ep2500 a 16ohm load). For some reason, I was thinking that these drivers were 2ohm

Now they're wired parallel... Holy Crap! Now I am hearing/feeling/EXPERIENCING what IB is really all about... WOW.

Thanks again, and very nice setup!

7,105 Posts
Discussion Starter · #15 ·

Originally Posted by Erich H /forum/post/16593116

Just curious, when you take the REW measurements, do most people select the 1/3 octave smoothing? I can't recall if I used that when I did my testing.

REW will take and record all the data, I played with turning the "1/3 octave smoothing" on/off and only affects the plotted graphs. I was advised to always plot graphs using 1/3 octave smoothing, makes them more readable and still accurate to real world. I did some searching, here good explanation. www.communitypro.com/files/literature/tech%20notes/SMOOTH_TECH.pdf

7,105 Posts
Discussion Starter · #16 ·

Originally Posted by kuks /forum/post/16590599


VERY nice room! I figured I needed to thank you
I've had 4 ae ib15s installed in my theater for a few months now and thought they sounded REALLY good... I'm still in the building phase, so no measurements or setup done yet.

Then I came across your thread and saw your wiring diagram posted... and I thought, "mine aren't wired up like that..." So, I ran downstairs to check --sure enough, my 8ohm drivers were wired in series(which would show my ep2500 a 16ohm load). For some reason, I was thinking that these drivers were 2ohm

Now they're wired parallel... Holy Crap! Now I am hearing/feeling/EXPERIENCING what IB is really all about... WOW.

Thanks again, and very nice setup!

Glad the thread detail helped you and that your IB sub "came to life".

I assume your IB15's have Re = 5.5 ohm like mine, so yours should also be:

1/5.5 + 1/5.5 = 1/R(e) = 0.3636

R(e) = 2.75 ohm load

7,536 Posts

Originally Posted by mtbdudex /forum/post/16595388

REW will take and record all the data, I played with turning the "1/3 octave smoothing" on/off and only affects the plotted graphs. I was advised to always plot graphs using 1/3 octave smoothing, makes them more readable and still accurate to real world. I did some searching, here good explanation. www.communitypro.com/files/literature/tech%20notes/SMOOTH_TECH.pdf

Thanks, yeh I knew it was only the way REW shows the final graph, but I wasn't sure if the graph that everyone posts has the 1/3 smoothing applied.

And now I do.

I'll check the link you posted as well.

7,105 Posts
Discussion Starter · #18 ·
I found better demo files than the danely ones, these 2 clips are of Saturn V rocket liftoff.

Via a search for "wav" in the "Subwoofers, Bass, and Transducers" avsforum, found member "ecox" posted download-able links to Saturn V launch sounds.

Here is a snippet of that thread posted 7/9/08:

(by avsmember "ecox")
As a gift to the bassheads here, I made .wav files of the two chapters, and they are here:

The 1st one: http://rapidshare.com/files/12845421...V_no2.zip.html

The 2nd one: http://rapidshare.com/files/12845421...V_no4.zip.html

Fair warning -- if your sub cannot go below 20hz with gusto, you'll likely either not hear and feel much of anything, or you'll blow up your sub. If your sub can go that low, then make sure things are bolted down and secure all over your house. Play these at your (and your sub's and your house's) own risk.

These two are now my "best", omg the cone movement and ultra low freq is un-real.

Definitely worthy of a YouTube clip.....

My wife was in the craft room oh say 40 feet away and she complained about the air pressure....

For those interested, here are the Saturn V liftoff video clips of my IB in action.

Saturn V rocket sound #2 clips driven by Infinite Baffle subwoofer "Usul"
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7,105 Posts
Discussion Starter · #19 ·
FYI, the speaker cone issue mentioned in the clips above has been fixed by AE speakers.

Below is re-cap my IB thread in the cult Sept-09 - Nov-09:

I identified a "clicking" sound in the top driver, I posted that Q on AE speaker forum for their feedback, possible I need a warranty replacement.

Just this 1 of my (4) AE IB15 is making a noise at 12hz thru 8hz, at 15hz and higher not making the sound.

It's nothing visually mechanical, not the wires/etc, sounds like inside the driver magnetic portion itself.

Before I posted in the AE speaker forum I confirmed not wire rattle, not loose hardware/nuts, etc.

It's only from the top speaker at freq 12hz or below.

To AE's credit and great service, I got return authorization and they handled.

John wants me to check one thing though:

Could you check the glue joint from spider to frame when you are playing those tones ? It could be something that broke loose.

Very-very satisfied with my AE IB15's.

Sure, I've gotten "18 envy" once or twice, but I can't imagine needing more spl.

The only thing I might do on my bass 2.0 improvement, besides more bass traps, is seeing if a 2nd "movable" sub could help with the null's my 1st row seats see's (and misses).

Besides seeing them in REW I can hear the difference.

But those nulls should also go away/reduce as I add more bass traps, so 2010 bass trapping making/install is on the docket.

I took #4 driver out, the top one in my IB line array:

Inspection every 90deg shot, no apparent damage just visually:

Very gently I probed with my finger I identified a glue separation and looks like a tear along this area, so that is what I must be hearing at ultra-low freq/excursion, it's rubbing against itself in/out cone movement:

I kept the original box, sent back in that.

Look how big just 1 of those are next to my kids!

I ran with only 2 drivers for a few weeks, pink foam to seal the hole.

After a few weeks I was very happy for the UPS last truck.....Box unpacking---Woofer PORN!! It's been awhile, I felt so dirty.

In process installed:

I'd like to report 4 months later everything is going smooth, low, and very clear!!!

1,917 Posts
That Saturn V clip is a beast but note that it is heavily clipped. I believe that was mentioned in the thread where it was posted. I don't think you have to fear with the IB15's though... I've thrown everything I can think of at my four (including clipping the EP2500 into them on the 7hz tone in "Bass I Love You") and they've never complained
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