WorldLeader

WorldLeader

Full Audioholic
Keeps getting better, love the IB setup!:D
Thanks! I just absolutely love the clarity and spaciousness of the sound, very open and live sounding with the room. It needs a rug still, but the reflections are not that big of deal.

I am also in love with this IB sub. Something about it makes it seem like it isn't there. No boomy-ness at all, just punchy and crisp. Even at low levels the sub blends perfectly.

I hooked up some small logitech sats to be my surrounds and Dolby PLII Music really sounds great. Easily the most transparent DSP IMO. :)

Ahh.... I love to listen to it. :D
 
W

westcott

Audioholic General
I would suggest reading about IB subs at the Cult of the Infinitely Baffled's FAQ page. They have tons of other stuff on that site as well, along with a message board to get personal help with projects there.

People who spend only around 600 dollars can run their IB from 10Hz to 60Hz flat.

You really only need
A) Either 2 or 4 large (15" -18") drivers
B) A pro-sound amp with adequate wattage
C) Build a baffle or manifold
D) EQ (not required)
I went to their site, and I admit, I did not read every page so keep this in mind when you read my following comments.

Although the theory is good, there is a lot more to subwoofer design than throwing together a couple of drivers and an amp. A subwoofer is a system, and this system needs to be designed to work with one another in a proper manner. I think IB needs to make more specific suggestions on amps used, how they step down, how quickly they should step down and at what octaves. I think there is a lot of potential in this design but to not make more specific suggestions is deceiving. I also have a big problem with placing a driver(s) in a wall that is not designed to be a speaker cabinet. One of the biggest issues is harmonic resonances and how they are addressed. Without knowing what kind of wall they are being placed in, how is one to know where these resonances are? And if you do not know that, how do you select an amplifier, driver, and crossover networks?

I also have a problem with placement. One can go to a lot of work to place an IB, only to find out that its placement does not provide a flat frequency response to the listening position. So, what do you do? Pull it out of the wall and try again? Their suggestion to use another sub to test placement is ludicrious. Every sub behaves differently, and placing a self contained sub NEAR where you think it will sound good has no correlation with the IB system and its unique characteristics.

I think people underestimate the amount of engineering that goes into building a subwoofer, and I will say it again, there is more to bass than going loud. I am all for saving money and getting good base, but I just want those who are considering this design to be aware of the potential pitfalls.
 
WorldLeader

WorldLeader

Full Audioholic
I went to their site, and I admit, I did not read every page so keep this in mind when you read my following comments.

Although the theory is good, there is a lot more to subwoofer design than throwing together a couple of drivers and an amp. A subwoofer is a system, and this system needs to be designed to work with one another in a proper manner. I think IB needs to make more specific suggestions on amps used, how they step down, how quickly they should step down and at what octaves. I think there is a lot of potential in this design but to not make more specific suggestions is deceiving. I also have a big problem with placing a driver(s) in a wall that is not designed to be a speaker cabinet. One of the biggest issues is harmonic resonances and how they are addressed. Without knowing what kind of wall they are being placed in, how is one to know where these resonances are? And if you do not know that, how do you select an amplifier, driver, and crossover networks?
Part of the problem with giving out general recommendations is that everyone and every room is different. Most people are running a receiver with a pre-out for the sub; an LFE output. For example I am running a Crest V650 in stereo mode (325 watts per channel) and it is rated from 10Hz to 20KHz. Some people opt to get an external x-over, but most people use the internal one in their pre-pro. Some people with more advanced x-over equipment run a sub from 80Hz-20Hz, then their IB from 20Hz down. This is kind of rare though.

As far as the wall being a speaker box, I had the advantage of knowing what the wall is like internally since I had just built it from scratch. I also did some additional insulating to keep internal vibrations under control. For the most part though, I don't think that drywall and insulation is that much of a compromise.

I also have a problem with placement. One can go to a lot of work to place an IB, only to find out that its placement does not provide a flat frequency response to the listening position. So, what do you do? Pull it out of the wall and try again? Their suggestion to use another sub to test placement is ludicrious. Every sub behaves differently, and placing a self contained sub NEAR where you think it will sound good has no correlation with the IB system and its unique characteristics.
True, but when bass is low enough to be non-directional, placement becomes a little less important. What most people do to combat this is simply choose the best sounding spot they can find, then work with the reflections with treatment, and EQ their way to a good response at the listening position. I found out where I wanted mine by simply playing some bass notes on my mains and listening to where the bass was stronger at.

I think people underestimate the amount of engineering that goes into building a subwoofer, and I will say it again, there is more to bass than going loud. I am all for saving money and getting good base, but I just want those who are considering this design to be aware of the potential pitfalls.
I think that you will be pleasantly surprised by the quality as well. I have yet to hear a commercial sub that can play at low volumes with quickness and ease, yet be able to shake the room at moderate volumes when the material dictates it.

Another thing that I think is nice about an IB woofer is that I do not have to deal with a giant box or tube in my room. Very low impact visually and physically, but it still puts out the bass like a monster. I spent about $450 total on mine, which would barely get a decent commercial sub. I got much more than a decent sub :D
 
W

westcott

Audioholic General
IB subwoofer design concerns

I do not think it would be productive to go on explaining why the IB design is not optimal.

I would rather suggest that you read the pdf file I am about to attach so you get a better understanding of how important subwoofer performance and placement is. Bass frequencies are "omni directional" or radiate in every direction from the driver. Not non-directional. Because low frequencies travel in every direction, its performance and placement is far more critical than any other speaker in a set up. Placing a sub closer to a corner will provide more dB, but usually at the expense of a flat frequency response. It takes a LOT of testing with calibration frequencies to properly place a subwoofer. Put it in the wrong place and the bass frequencies muddy the rest of the frequency range of ALL the speakers.

Once again, I am not trying to bash your system, just trying to educate you and others that might be interested in this topic.

I could go into a lot of other things like 2pi driver designs vs. 4pi, slope settings, etc. but the point is, bass is not all about boom!

I hope that you do read the article I attach. I think you will acquire a much greater appreciation for how important subwoofer placement is and how much work goes into low frequency managment.

Subwoofer placement and How Many


http://www.audioholics.com/search?SearchableText=subwoofer+placement
 
Last edited:
WorldLeader

WorldLeader

Full Audioholic
Thanks for the links, they are very helpful :)

To be perfectly honest, I chose my location mostly due to convenience.

Either way, I could have done worse with the spot I picked. I also needed to take into account that I listen to music all over the room, so factoring in all these possible seating positions would have been a mess. It sounds best from the couch, but still sounds fine everywhere else. ;)
 
WorldLeader

WorldLeader

Full Audioholic
Man, today I realized that I can actually turn up the subs when no one's home! :eek:

Let's just say with the amp at about 60% power I was getting a weird feeling in my stomach. Things were falling off shelves, I swear my stool moved a bit, it was pretty weird. Forget those car subs that make lots of noise but only play 30Hz, these babies were pounding out subsonic notes just as loud, and the cones hardly were moving! :confused:

I was watching The Prestige and it kind of freaked me out with these really low rumblings that I hadn't heard before on my old Logitech setup. Ominous.

I love it! :D
 
abefroeman

abefroeman

Audioholic
Westcott:

for someone to go from this ignorant statement....

Does IB provide drawings and dimensions on how to build the woofer boxes?
....to this post....

...I also have a problem with placement. One can go to a lot of work to place an IB, only to find out that its placement does not provide a flat frequency response to the listening position. So, what do you do? Pull it out of the wall and try again? Their suggestion to use another sub to test placement is ludicrious. Every sub behaves differently, and placing a self contained sub NEAR where you think it will sound good has no correlation with the IB system and its unique characteristics..
is pretty arrogant. You have no way idea of what an IB is capable of.

Worldleader... your IB setup looks perfect from my understanding of how an IB should be setup. It is right smack in the middle of the mains, which is almost always the ideal spot for an IB. It looks like you did your research. (you probabaly did more than just read through some of thier site) I would imagine that your setup plays with as much clarity of bass as anyone on this forum with an untreated room.

Props for the IB setup!

I live in an appartment, but one of my first projects when I get a house (a year or two) is an IB sub similar to yours. I am going for 2 FI Q18 drivers or 2 FI SSD drivers in an IB configuration exactly as you have them in your loft (or possibly in stereo, one behind each main speaker).

great setup, you are on the right track. Now make some bass traps and acoustical treatments.
 
W

westcott

Audioholic General
is pretty arrogant. You have no way idea of what an IB is capable of.
Thats the problem. NO ONE does until they already have it installed. Placment is just as, if not more important, than the equipment and until it is installed, no one can predict its performance in the room or if it has been placed in the proper position.

I agree that the center of the wall is probably where I would suggest placing the IB if I had to make an educated guess. But, that is all it would be, a guess.
 
abefroeman

abefroeman

Audioholic
Thats the problem. NO ONE does until they already have it installed. Placment is just as, if not more important, than the equipment and until it is installed, no one can predict its performance in the room or if it has been placed in the proper position.

I agree that the center of the wall is probably where I would suggest placing the IB if I had to make an educated guess. But, that is all it would be, a guess.

10 minutes ago you thought IB was a brand, go read about IB placement before posting about it.

Sorry for the Hijack world, when are you getting those DIY speakers built?
 
W

westcott

Audioholic General
10 minutes ago you thought IB was a brand, go read about IB placement before posting about it.
I guess changing the subject is a good way of avoiding a discussion based on facts. AND, since my comments were made in March, 10 minutes ago is far from accurate, as well. I did read their placement suggestions and substituting a stand alone subwoofer for testing has no basis in reality either. To suggest that this method will recreate the same bass response is optomistic, at best, but I had already stated this earlier it this rather old thread.
 
ParadigmDawg

ParadigmDawg

Audioholic Overlord
Are you out of your mind; have you not seen what he has done here?

I do not think it would be productive to go on explaining why the IB design is not optimal.

I would rather suggest that you read the pdf file I am about to attach so you get a better understanding of how important subwoofer performance and placement is. Bass frequencies are "omni directional" or radiate in every direction from the driver. Not non-directional. Because low frequencies travel in every direction, its performance and placement is far more critical than any other speaker in a set up. Placing a sub closer to a corner will provide more dB, but usually at the expense of a flat frequency response. It takes a LOT of testing with calibration frequencies to properly place a subwoofer. Put it in the wrong place and the bass frequencies muddy the rest of the frequency range of ALL the speakers.

Once again, I am not trying to bash your system, just trying to educate you and others that might be interested in this topic.

I could go into a lot of other things like 2pi driver designs vs. 4pi, slope settings, etc. but the point is, bass is not all about boom!

I hope that you do read the article I attach. I think you will acquire a much greater appreciation for how important subwoofer placement is and how much work goes into low frequency managment.

Subwoofer placement and How Many


http://www.audioholics.com/search?SearchableText=subwoofer+placement
 
Haoleb

Haoleb

Audioholic Field Marshall
Very nice setup, But There is one thing that If it were my room i would be quite concerned about and that is of course the gaping hole in the floor. A railing would ruin the look of the room, But what about making a reinforced plywood door that when closed will look like the floor, and you can walk on it or whatever. You could even have spring tensioned hinges to help lift the weight of the door.
 
Haoleb

Haoleb

Audioholic Field Marshall
woops. nevermind, I see you already put up a railing :D
 
picture_shooter

picture_shooter

Full Audioholic
Bringing back 2007!! Sweet!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!! :D
 

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