My IB Adventure (lots of pics)

**Chrisbee** · **06-26-06, 04:10 AM**

Excellent work Darren with some nice clear pics to show what's really involved.

For those still wondering how loud the bass is in the back of an Infinite Baffle it's exactly the same as in front of it. Just turn off your speakers and listen to your sub alone. It's as simple as that.

It's not exactly unpleasant in the rear space if you use an adjoing room for your enclosure, as I have done. The very low frequencies involved are not very audible anyway. Having blanket insulation in the rear space will absorb a lot of bass as it bounces repeatedly around in there. I have no damping and a wall of glass end gable forms the far end of my IB enclosure.

My 16-46 sounds louder outside the house than my IB does. My wife often comments on the difference when she comes back in from gardening when I have been listening to music or watching a film with the IB.

I can get away with much higher volume levels with the IB. I spent some time wandering around our garden listening carefully to noise levels coming from indoors.

Ten yards away from the house you can hardly hear a thing from the IB. You can still (just) hear the cylinder at 30 yards. Naturally all windows are kept closed during listening sessions despite having no near neighbours.

I wonder whether the much lower distorion levels of the IB mean the much more audible harmonics are completely absent?

**Darren** · **06-26-06, 12:06 PM**

Getting excited

Only a few more hours before the two additional 15" drivers show up on my doorstep. I feel a movie night coming on!

**Sonnie** · **06-26-06, 09:06 PM**

You ought to have those things installed by now...

we want news!

**Darren** · **06-26-06, 11:17 PM**

Yup, got them installed right after I got home...95 degrees out and an hour in the attic will cause you to lose a few pounds of water

I didn't have time to really test things out because I had to run and just now got back home. Adding the two drivers really reinforced the bass down low. Big difference there. Output was increased overall but not as audible a difference as I would have expected but I guess it would only add a few db with the additional drivers and wattage...stands to reason. The big gain as I mentioned above is the bass reinforcement... much less effort and my tone sweep that causes the earthquake sensation is unreal now. The house LITERALLY moves. The floor and walls actually physically shake...my house is a 2X6 stud wall custom home built like a brick sh...well you know what I'm saying.

I'm running into overhead problems with my amp though. It's a behringer EP1500, I'm running 4ohm stereo right now so it should be 400wpc. I have the gain about half way and am experiencing some clipping. I could go 4ohm bridged mono but am not sure if that is a good move or not.

At any rate, so far so good. I am noticing that the drivers are giving out a bit in the more dynamic HT scenes. I'm thinking that is because they are 14mm XMAX where I'm used to 24mm or so XMAX of my other subs. I'm purposely running these drivers near their limits with caution. I would have thought the drivers would give out before my amp but like I mentioned above, my amp is slightly clipping on dynamic scenes and I'm not yet at the output I ultimately desire. I'm dang close though. The drivers have never bottomed but I have reached their useful limit occasionally from what I can tell.

My current thoughts before really testing them critically is they are well worth the estimated but not final list price. I can't disclose that until Darrel decides to make it public. They appear to be a very well built driver and really perform admirably.

Stay tuned for new plots and tests... Really, the house literally shakes with my sweep.

Here is the required "head" shot... I'm dripping sweat on the camera

**jmprader** · **06-26-06, 11:36 PM**

When is the Man Show going to pick up DIY subaholics and give them their due. We all secretly lust after our own, and all that it can do for our male egos and those of our more enlightened friends.

**Sonnie** · **06-27-06, 12:21 AM**

Good question John... lol.

Darren... thanks for that "head" shot... looks almost like you are lying in a coffin

From what I'm gathering even if you had subs with more xmax you might not be able to drive them with that amp?

**Chrisbee** · **06-27-06, 04:21 AM**

I hope you're running them in series pairs now you have four?

Running them in parallel pairs is only 2 Ohms per channel.

Behringer say their amps can take it but I wouldn't risk it.

**Darren** · **06-27-06, 08:32 AM**

Sonnie,
I should be able to drive anything with this amp, I'm currently running 4ohm Stereo = 400wpc. I'll be bridging it mono tonight which will boost me to 800 watts into 8 ohms.

Chrisbee,
They are 8 ohm svc drivers, so I'm running 4 ohms in parallel currently.

**Darren** · **06-28-06, 11:57 AM**

Ok, I have been running 4 for a day or so now at 800 watts bridged mono. The additional power helped with the quality of sound at higher volumes. I've finally pushed the drivers to their limit but it wasn't easy actually. It took a 20Hz tone cranked well beyond my normal LOUD listening levels. They bottomed momentarily and I killed the volume. I needed to find the mechanical limits of the driver so I knew I was pushing them appropriately.

Bass has improved all around with the new configuration. I have noticed at a few select frequencies (I'm not sure how to test/isolate them accurately in music) on some heavy bass tracks can cause the clean bass notes to "distort" or become loose. The really low frequencies are very clean and solidly reproduced but when the subwoofers really get to moving quickly on the higher bass notes there are a few where it goes from "holding" the note or frequency to kind of distorting or flopping or something. Hard to describe. My next test is to try and figure that out. Might be the cabinet resonating, maybe the drivers need to be secured more tightly, or maybe there is a spike in the response at that frequency that is overdriving them...

**Ayreonaut** · **06-28-06, 04:09 PM**

Since you are "beta testing the Silver Iris B.A.D 15" IB drivers" I guess you'll have to deterine what part, if any, of the distortion is due to the limits of the drivers. Are you going to secure any other drivers to do a comparison?

**Darren** · **06-28-06, 04:11 PM**

Currently I have no other drivers for comparison... I'll probably be buying different drivers shortly after the beta test is over as I've been waiting 5 months to do this and can't wait any longer to get my permanent drivers. I'll have some comparison then so that should help. I'm going to stiffen my box tonight to see if that changes anything. It is a stout box so I doubt that is the problem... a possibility might be that the drivers need to be secured better. I'll look into that too.

**Darren** · **07-01-06, 02:15 PM**

After some testing with just the subwoofer operational I believe I can say the strange vibration was just that... house vibration. When the mains are on this noise is of course drowned out but with just the subwoofer on I could definately tell it is some shelves, cabinets, coffe table, trinkets rattling creating the issue.

I did measure output at 112db with just the sub operating in the seating position during my tests... Yee haw!

**Darren** · **07-16-06, 09:45 AM**

Ok, after some sole searching I decided my permanent drivers would be the SoundSplinter RL-P15 D4. I ordered 4 of them and they arrived on Friday. I just needed the extra xmax these drivers could provide for the SPL I desired and was used to.

I have done some brief listening tests and while you pay for the extra xmax it really improved the headroom and output. I'll be taking some mearsurements in the next few days. Until then here are some pics:

The RL-P15 drivers, they make me happy just looking at them:

Up close:

The manifold with the new drivers installed, pay no attention to the messy wire, I had to listen quickly

And the busisness end!

**Chrisbee** · **07-16-06, 09:54 AM**

It makes me happy just looking at them too!

Superb drivers and some high quality pics.

Can't ask for much more than that.

Keep us informed of progress.

**Vaughan Odendaal** · **07-20-06, 05:36 PM**

Stupid question time : what is that thing on the subwoofer where the wires are connecting to ?

**bobgpsr** · **07-20-06, 06:09 PM**

Quote:

Vaughan Odendaal wrote:

Stupid question time : what is that thing on the subwoofer where the wires are connecting to ?

A Cinch strip? Screw terminal barrier connection block.

Bob

**Vaughan Odendaal** · **07-20-06, 06:21 PM**

I've never heard of it to be honest. Where can you buy those ? Because I am also interested in building an IB. I was hoping to use the Dayton 15" DVC (four of them).

But when it comes to connecting these things I'm a little confused. I might need a *little* help.

**bobgpsr** · **07-20-06, 06:31 PM**

Mouser Electronics. Google it.

Bob

**Darren** · **07-20-06, 06:35 PM**

You can get those barrier strips at most electronics stores...possibly even radio shack.

**Sonnie** · **07-20-06, 10:27 PM**

So those are what I have to look forward to huh?

Nice!

**FlashJim** · **07-21-06, 09:49 AM**

Thanks for posting the pics, Darren. My wife loved them. (read: she'll let me do an IB now)

**Darren** · **07-21-06, 10:36 AM**

Quote:

FlashJim wrote:

Thanks for posting the pics, Darren. My wife loved them. (read: she'll let me do an IB now)

Glad to have helped!

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