[Nimby]

Hi

I really ought to have shared my new toy with you all by now:

I've been busy building a True Infinite Baffle subwoofer into the wall that separates a sunroom from my 30 feet long attic listening room.

The 1.5" thick laminated plywood baffle holds 4 x AE IB15 drivers. The sunroom enclosure is around 9 cubic metres which is on the small side for 4 of these specialised 15" drivers.

The space available to fit the drivers in a vertical array was very tight but worked out just fine with some careful juggling of the speaker spacing on some scrap ply.

My new sub will be driven by a stereo Behringer EP2500 pro amp in 8 Ohm series pairs per channel. A CX2310 Behringer active crossover will seperate the signals coming from my Naim preamp before they reach the Naim power and EP2500.

These are under-construction pictures to show a mock-up and then the drivers in place. It sounds superb even without the pro-amp to drive the TIB.

I know this is a really DIY sub project. But since I spend most of my time on the sub forum I'm sure those nice mods will turn a blind eye for once.

[eviljohn2]

That's looking great Nimby.

Can't wait for some more pics - it's amazing how discreet Infinite Baffle designs like this can be with a bit of effort.

[Nimby]

Thanks John. Not sure whether I want to hide the drivers from the listening room side, or not.

Thought I'd put a louvered door over the backs of the drivers just to keep the sun off.

[Jammyb]

Wow! All that to recreate the brown noise?

I'm guessing you don't have any neighbours?

[paulst10]

wow! nimby your house must ROCK!

is this replacing your SVS ?

[Nimby]

Rural detached really means I have Nobody In My Back Yard.

The point of a TIB subwoofer is high sound quality as well as hgh output.

The large area of the speaker cones means they hardly move to reproduce high sound levels at very low levels of distortion at very low frequencies.

I've already seen 110dB uncorrected from the listening position on only 45 watts per driver with hardly any volume on my preamp. I'm pretty sure it will do 120dB given enough welly.

The clarity of the bass is simply quite amazing, even now. I'm discovering all sorts of bass I've never heard before on CDs I've played loads of times.

I'll run a response curve once I have enough power to do the IB justice. It's sharing the 90 wpc stereo amp with my speakers until tomorrow. Then I get the pro-amp with 500 watts per channel into 8 Ohms.

Only a TIB sub can play down around 5-10Hz thanks to virtually no back pressure. Blackhawk Down should be good fun. It has a hot 5Hz moment. War of The Worlds is supposed to be insanely heavy at frequencies that go completely unnoticed on other subs.

As to my SVS.. I'm still undecided whether I want to sell it or store it away safely in case I ever move from here. They may never be available in Europe again.

Now I just need a new sig!

Bassy days are here again ... tra-la!

[Nimby]

Here's some pretty pictures of the 15" drivers:

[Ettepet]

Great stuff!

I hope I can make an Infinite Baffle sub in some future apartment.

[Jammyb]

My dream combo would be one of those, with the back room also acting as a space for a rear projection setup. the picture is supposed to be a lot better, but you hardly ever see them on this side of the pond afaik.

[Nimby]

I've been listening to organ music for hours with the IB today. It has such effortless authority and plays tunes with such clarity. The incredible weight and power of the Chichester cathedral organ with a TIB is unbelievable. The characters of the stops are so faithfully reproduced.

I won't bash the 16-46 because it has given me a lot of pleasure over the last couple of years. All for a remarkably small investment. (around £500 delivered to the door) The SVS was the best investment I've ever made in 40 years of hifi. At least until now. But there is simply no comparison with the TIB. None whatsoever! Not even in the same ballpark! Remember this thing is still running on mere candle-power and the drivers not even run in. I've hardly seen the cones move yet while the driver in the big cylinder used to thrash away like a mad thing!

I can't wait to get the pro-amp wired up if it arrives tomorrow. I just hope the old windows can take it!

[recruit]

Good Stuff Nimby

[Nimby]

Thanks for the interest.

You really have to experience one of these!

[IronGiant]

Looks great Nimby, are the glass panels in the door there to act as a safety valve?

Dave

[Nimby]

Originally Posted by Regmarch

Looks great Nimby,

Dave

Thanks. It sounds far better than it looks at the moment.
My pro amp didn't turn up as promised today!

are the glass panels in the door there to act as a safety valve?

No, they're there to let the light in.

[Ilkka R]

That blue wire looks really thin. You should use a thicker wire. At least something like 2,5 mm^2.

Otherwise it looks great and I probably sounds even better. Congrats!

[Nimby]

Originally Posted by Ilkka R

That blue wire looks really thin. You should use a thicker wire. At least something like 2,5 mm^2.

Otherwise it looks great and I probably sounds even better. Congrats!

Thanks Ilkka. An IB sub is certainly a unique experience. Even on very low power.

The wire is just bits of 0.75mm^2 mains flex. I'm presently running the IB (2 x 4 Ohm series pairs for 8 Ohms) in parallel with my main stereo speakers using my 90 wpc (4 Ohms) stereo amp. I seriously doubt these wires are seeing more than a few wpc at present volume settings.

When I start using a pro amp to drive the TIB in the next few days I'll have 500 wpc (8 Ohms) I shall certainly be using much larger cable cross sections and being very careful not to exceed the drivers' limits.

A more careful measurement of my IB "enclosure" suggests I shall have around 16 cu.meters rather than the 9 cu.meters mentioned above.

[Andywilliams]

In a few months time you will be saying !!PARDON!! to everybody

[Nimby]

Pardon? The latest research shows that low frequencies even in excessive quantities are the least damaging to hearing. Our world is full of infrasound and has been for millions of years. Crashing waves, wind, earthquakes and volcanics do not seem to make us deaf.

The IB isn't all about sound levels. More about quality, clarity and realism. Instead of merely playing impressively low frequencies like any other sub the IB tells you exactly what is happening. What is making the sound. When it starts and stops and exactly how it did both. This sense of realism is quite a shock compared with all the subwoofers I have heard.

It is the frightening weight and authority which is such a feature of the IB. Instantly loud. As massive as a truck in the room. Then stops dead to absolute silence. It is the complete absence of build-up and total lack of overhang which catches you off-guard. You have no time to prepare yourself. BANG!

[Timbo21]

Nice one Nimby. When are you taking orders ?

[Nimby]

Originally Posted by Timbo21

Nice one Nimby. When are you taking orders ?

Shsh!

I've been taking orders from SWMBO for forty years.

Actually she's very good. There aren't many partners who would let their lesser halves make large holes in the wall and then put 4 big speakers in there.

She accepted the big SVS cylinder very quickly too once she knew how good it was on her favorite rock music.

[Timbo21]

Originally Posted by Nimby

She accepted the big SVS cylinder very quickly too once she knew how good it was on her favorite rock music.

Well, by the sounds of it, you're going to be very popular. Has she had a listen yet?

[Nimby]

SWMBO is not happy.

Despite the colossal improvement in bass quality she does like a bit of serious welly behind her rock music.

Given a few hundred more watts I believe she can be won over.

I'm just praying one of us will survive long enough to tell the tale!

Nimby that looks awesome wish i could hear (feel) it

(jealous as hell ) looking to build one of my own when I get to my new home. You were lucky to have so much space to build it (manifolds are a pain to build and can give you phase issues).

[Timbo21]

Originally Posted by Nimby

SWMBO is not happy.

Despite the colossal improvement in bass quality she does like a bit of serious welly behind her rock music.

Given a few hundred more watts I believe she can be won over.

I'm just praying one of us will survive long enough to tell the tale!

I think what you need to do, to be absoloutely sure you will win her over, is...

build another .

[Nimby]

Not very impressive at the moment! Mumble-mumble)

The Behringer EP2500 finally arrived and it isn't nearly loud enough!

I've tried feeding the IB with a full range signal to bypass the CX2310 crossover in case I made a mess of the settings. (Though it worked fine using the Naim amps)

The pro amp needs more than 12 o'clock on the volume controls just to be able to hear the sub speakers are working!

The speakers are wired 2 x 4 Ohms in series pairs for 8 Ohms. One pair per channel. I'm using original CableTalk3 for cabling now with good cross sections. Bare wires checked for stray strands at all terminals and are clean.

It seems like a serious signal level mismatch between the Naim preamp and the pro amp. The signal LEDs on the pro amp are only flashing on now and then when I turn the preamp volume up high.

I'm using quality Din to 2 x XLR (for stereo) cables from the Naim preamp to the pro amp. These worked fine as a direct replacement for the Naim Snaic with the XLRs plugged into each other.

Do we have any tame pro-gear experts could advise please?

[Sniper]

Not 100% on this - but the balanced inputs are usually @ -6db.

Try the RCA input!

EDIT: just had a look at the EP2500 manual - there's no RCA input. Specs say that input impedance is 20kohm for balanced and 10kohm for unbalanced. Seems to me you're feeding an unbalanced signal to a balanced input. Check the manual it tells you hot to connect an unbalanced signal.

[Nimby]

Thanks Sniper.

I overcame the problem with a couple of dB LF gain on the active crossover.

I had been warned there would be a level mismatch.

It sounds great now.

[Sniper]

np: be sure to post a review of this 'sub' system. A couple of graphs would be nice too ;-)

[eviljohn2]

Pro amps are designed to be run at full whack. You don't generally control the gain on hifi amps and in your situation I don't see any necessity to on yours. Turn it up as far as you like.

[micb3rd]

I'm pretty sure it was me that convinsed you to change from your DIY bandpass subs

I totally subless at the moment so I'm feeling quite deprived of bass.

Seeing this makes we want to cry, fantastic job Nimby!