Infinite Baffle

[Bigpete123 1]

Hi!

I was hoping to get ya'lls (sorry, I'm not from the south so I may have spelled that wrong) input on infinite baffle setups. To preface, I'm not very interested in SPL... I'm an SQ guy. So I know one of the downsides is that I won't get loud booming bass with my setup.

But what are the other drawbacks and/or benefits, assuming that I seal my trunk off perfectly? All I've used in the past were sealed enclosures and I really liked the quickness of my subs. Due to the way my trunk is laid out, though, it makes it pretty tough to build an enclosure that's attached to the rear deck (trust me!). So IB will be the easiest installation, I think.

So set me straight!!

Peter

Edited May 26, 2006 by Bigpete123

[JimJ 11]

Best low frequency extension, excellent transient response, higher efficiency than a smaller sealed alignment...

Drawbacks are you're not going to get a lot of output like you mentioned, and if you have a lot of amplifier power, you're going to be using a fraction of it.

[Bigpete123 1]

Best low frequency extension, excellent transient response, higher efficiency than a smaller sealed alignment...

Drawbacks are you're not going to get a lot of output like you mentioned, and if you have a lot of amplifier power, you're going to be using a fraction of it.

<{POST_SNAPBACK}>

Cool, thanks. I'm actually only running 250w RMS to my sub... so I'm not terribly concerned about power. According to my owners manual, my sub can handle around 200watts RMS via IB.

I'm surprised that you mentioned the transient response is excellent. Is it better than that of a sealed enclosure?

[Tirefryr 1,742]

Assuming you have a driver with a suspension capable of this alignment, IMO it is the ultimate sound. People complain about lack of output, but I've had 2 setups that could get very loud to my ears. The key is the 100% seal. It is very tough due to the structure of the unibody vehicle. YOU have to make sure you find every spot where there could be a leak. Little places like the C-pillars where they connect to the deck, yes, these will have holes in them allowing air to pass.

If you implement it correctly, I think you will LOVE this application.

[Bigpete123 1]

Assuming you have a driver with a suspension capable of this alignment, IMO it is the ultimate sound.  People complain about lack of output, but I've had 2 setups that could get very loud to my ears.  The key is the 100% seal.  It is very tough due to the structure of the unibody vehicle.  YOU have to make sure you find every spot where there could be a leak.  Little places like the C-pillars where they connect to the deck, yes, these will have holes in them allowing air to pass.

If you implement it correctly, I think you will LOVE this application.

<{POST_SNAPBACK}>

Yeah, the sub I'm using is the Infinity Kappa Perfect 10vq. The "vq" in the model number stands for "variable Q"... You can alter the Q of the sub by changing out some inserts that you stick in the magnet. Thus, it can be used for ported, sealed, and IB applications. The suspension (to the touch) is more stiff than any other sub I've used... And I'm going to back off the input sensitivity on the amp to match the sub's ~200watts RMS IB spec. So I think I'm cool in that arena.

My rear deck is very well-sealed, but I may have to caulk some spots and do a very detailed inspection to make sure it's perfectly sealed up. I've already used some metal from some HVAC ducting, some caulk, and self-tapping screws, and some damplifier pro to seal up the more major holes... But there's more work to be done, I guess.

One problem is that the rear headrests can go up and down... So they have a hole through the rear dash, and I haven't figured out how I'm going to seal them without making them unusable. But we'll see.

I'm excited to hear that this will sound good!

Peter

[Aaron Clinton 2,372]

I was just thinking about the head rest supports. I have no idea how to seal them up

[Bigpete123 1]

I was just thinking about the head rest supports.  I have no idea how to seal them up

<{POST_SNAPBACK}>

I know... it's a pretty PITA the more I think about it. I wonder if I could find a boot similar to one you'd find on a stick shift... Of course, if the material is too soft, the pressure caused by the sub will make it move... so it won't do any good.

I might have to build a "boxes" around the mechanical apparatuses and seal it up that way, but with the gas tank located where it is... it might be hard to pull off. We'll see. Troubleshooting things like this is part of the fun of it!

I also need to seal up the areas where the cables come into the trunk on both sides of the gas tank. I'll probably build small boxes out of MDF and caulk to do that. Good times!

[Aaron Clinton 2,372]

would you consider sealing the head rest mechanizm from the trunk? I have to look in my trunk to see if that is possible...

like a closed compartment under them, eer I dont know just throwing out an idea

[///M5 2,833]

Assuming you have a driver with a suspension capable of this alignment, IMO it is the ultimate sound.  People complain about lack of output, but I've had 2 setups that could get very loud to my ears.  The key is the 100% seal.  It is very tough due to the structure of the unibody vehicle.  YOU have to make sure you find every spot where there could be a leak.  Little places like the C-pillars where they connect to the deck, yes, these will have holes in them allowing air to pass.

If you implement it correctly, I think you will LOVE this application.

In fact most C-pillars are purposely "vented" into the cabin, I never have understood why but they are. A couple careful, quick shots of expansion foam can take care of that though.

[Tirefryr 1,742]

Assuming you have a driver with a suspension capable of this alignment, IMO it is the ultimate sound.  People complain about lack of output, but I've had 2 setups that could get very loud to my ears.  The key is the 100% seal.  It is very tough due to the structure of the unibody vehicle.  YOU have to make sure you find every spot where there could be a leak.  Little places like the C-pillars where they connect to the deck, yes, these will have holes in them allowing air to pass.

If you implement it correctly, I think you will LOVE this application.

In fact most C-pillars are purposely "vented" into the cabin, I never have understood why but they are. A couple careful, quick shots of expansion foam can take care of that though.

That's what I've done in the past. Hell, I had over a year invested in my Cutlass just sealing it. I went to th extent of cutting braces out to get to impossible to reach places and them welding them back in place.

On another note, do you have any photos of the headrests and mechanisms? I think some type of O-ring seal would work well.

[///M5 2,833]

Or you could build mini enclosures around them on the inside of the trunk. PITA, but maybe easier depending on the mechanism.

[Bigpete123 1]

Yeah, reading my last post, I didn't explain myself very well. But I would probably build mini-enclosures around the mechanisms... The enclosures would have to be large enough for the headrests to be able to collapse.

Here's a pic of the interior dash. Note one headrest is up, one is down:

And here's one from inside the trunk showing the mechanism:

Let me know what you guys think!

Thanks for the input!

Peter

Edited May 27, 2006 by Bigpete123

[Tirefryr 1,742]

Oh yes, an enclosure would be so simple.

[Eldorado 0]

x2, just make an enclosure

[Aaron Clinton 2,372]

hey Pete, do you mind if I ask what is to the right of the port side head rest

[Bigpete123 1]

I think you're looking at the drivers' side rear speaker. I had the grille removed at the time. That hole is now sealed and covered with sound deadening material... So I'll be making a custom FG enclosure there. More fun!

[Aaron Clinton 2,372]

I think you're looking at the drivers' side rear speaker.  I had the grille removed at the time.  That hole is now sealed and covered with sound deadening material...  So I'll be making a custom FG enclosure there.  More fun!

we get some pixtures of the progress,

I need some help here, only 2 of us MB guys that are into real audio, hey you know anyone else on MBWorld or MercedesShop that would come over?

[Bigpete123 1]

hmm, I'm not sure... I'll try to spread the word though!

[Aaron Clinton 2,372]

hmm, I'm not sure... I'll try to spread the word though!