Got a question on Infinite baffle
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New member Username: EasylookerPost Number: 1 Registered: Aug-05 | Was wanting to know if any of you guys have ever used this type of setup before and what type of subs you guys used. I know that typically you need a sub with a QTS of .5 or greater to work in an IB setup. I would go with a box of some sort but I have many problems regarding my trunk of my car. I drive an 02' Concorde limited with a leather interior. Presently I have two Vibe 1800D(Lanzar) amps pushing 4 max 10's the square subs. My installer has them in a sealed box of around 1 cu.ft a piece. The subs face toward the rear of the car. My problem is the way my trunk is shaped Bass cannot penetrate into my interior and the weight is quite a bit. My amps are running at 1 ohm and I blew a couple of the subs when I moved the gain a little past halfway. I do not like how low the subs play thus the box needs to be bigger. I don't have enough volume in the car (supposedly the guys said I was hitting in the 150's I don't believe them) theres too much weight in the trunk (my mpg has dropped big time), my leathers seats are so thick that the volume that is there doesn't bleed through well etc etc. My back deck is made of metal so there is no way that a port can go through there and I'm not cutting either. So I've come down to the IB setup. Some guys ran this when I first got into caraudio back in the late 80's but I have not seen this as of late. My trunk is close to 20 squre ft I could possibly put 2 15's or 3 12's behind the seat and put the armrest down on the back seat and the plastic piece comes down also and has an opening of around 8"x8" My trunk is shaped funny, I have approximately 15 1/2 inches top to bottom behind my seat and it goes back about 3 inches before the rear deck lid closes the gap to around 13". Same way with the width also wide at the back seat then about 5 inches back it closes up to about 35 inches. Any help and or experience would be greatly appreciated. |
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Bronze Member Username: ShepyjayOnt Canada Post Number: 38 Registered: Feb-06 | kicker has free air subs give us a pic of the trunk and ill go from there |
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New member Username: EasylookerPost Number: 2 Registered: Aug-05 | I'd like to take a pic if I could and knew how to upload to a computer and my trunk is full of box and subs. I'm familar with the Kicker subs I believe they make them in 8 and 10". Here is a car like mine wrong color mine is black on black. http://www.cardomain.com/ride/2130767 Scroll down on this link and you can see a pic of a trunk of a concorde. Here is a pic of a trunk but it does not show how deep it goes. Its probably another three feet deeper to the seats than this pic shows http://cgi.ebay.com/ebaymotors/03-LEATHER-CD-LUXURY-SEDAN-TRACTION-POWER-WOOD-CH ROME_W0QQitemZ4617781514QQcategoryZ31828QQssPageNameZWDVWQQrdZ1QQcmdZViewItem#lg Here is a look at the trunk deeper in but does not show how it widens back out and gets taller next to the seat its around 13.5" at its shallowist point and around 15.5" inches behind the seat. http://cgi.ebay.com/ebaymotors/2002-Chrysler-Concorde-LXI_W0QQitemZ4615685185QQc ategoryZ31828QQssPageNameZWDVWQQrdZ1QQcmdZViewItem |
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Platinum Member Username: GlasswolfWisteria, Lane USA Post Number: 11302 Registered: Dec-03 | Jonathan is a fan of IB setups. Personally I'm not. |
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Gold Member Username: Jonathan_fGA USA Post Number: 5673 Registered: May-04 | Lower Qts subwoofers tend to give a flatter response IB than higher Qts do in a car. They're overdamped, but you have to factor in cabin gain. "Jonathan is a fan of IB setups. Personally I'm not." Rather have AP, or transmission line  . I prefer IB for midrange, but that's a given. |
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Platinum Member Username: GlasswolfWisteria, Lane USA Post Number: 11327 Registered: Dec-03 | well yeah but I thought you'd said that you've herd good IB setups for subs.. I honestly have never heard an IB setup that played all that low. They all sound fairly washed out to me, but I'm so used to well powered systems with a lot of damping beind the drivers.. so maybe it's just what I'm used to, or what my ears prefer. I laughed when I saw you posted last in this thread. I wondered if you'd respond.. haha |
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New member Username: EasylookerPost Number: 3 Registered: Aug-05 | Richard Clark always seemed to do well with the IB set ups. |
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Silver Member Username: MixneffectOrangevale, Ca. USA Post Number: 845 Registered: Apr-05 | I dont get it. Where do you want to install the subs? IB means that you still have to have the subs facing the inner cab, which means that you will still have to cut the rear deck lid. Or, Do you plan on putting them in the cab? If I were you I would just get some bass shakers, and some low hittin 6.5" or 7". Fitting some larger shallow mount drivers in the cab might give you more bass without the extra amp/subs problems. The same problem exists in open cab vehicles such as convertibles, jeeps, and unibody vehicles (vipers). |
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Gold Member Username: Jonathan_fGA USA Post Number: 5687 Registered: May-04 | Some subs do ok. Most do lack low end compared to other enclosures, but they didn't sound bad by any means. I think Jason Winslow hit high 130s in the 35-40hz region at finals with his, he had 3 ID Maxes IB on the rear package tray. Something like that. For some reason IB is making a comeback. Scott Buwalda had his subs IB in the Altima. Won finals in it, I guess it wasn't too bad. Those were the DLS Iridium subs, have a higher Fs. Maybe that's the key to subs doing well IB, getting a high enough Fs so that you'll get efficiency where you want it. |
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Bob365 Unregistered guest | From what I read in your post, IB would not help you at all. The problem is that your trunk is pretty well sealed off from the rest of your car. If your car is setup the way I think it is, there's a solution. You do a ported box with the port lined up where the armrest drops down. I believe the one I saw was a custom fiberglass setup, but it could be done with mdf. |
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Gold Member Username: Mikechec9Http://www.cardomain.c... Post Number: 2211 Registered: May-05 | "I guess it wasn't too bad. Those were the DLS Iridium subs, have a higher Fs. Maybe that's the key to subs doing well IB, getting a high enough Fs so that you'll get efficiency where you want it... Lower Qts subwoofers tend to give a flatter response IB than higher Qts do in a car. They're overdamped" This is still a bit confusing to me, b/c Scott suggests HIGH QTS numbers as being the key to an effective IB sub. He actually employed the UR 12 subs for their stiffness and high QTS. They eventually lossened and he switched to the OA 12's with an even HIGHER Q. So even as the Q dropped due to "break-in," it would still be sufficient enough to use in a huge enclosure. Also, I recall Jeff Smith and Scott B. posted some of the highest SQ AND SPL numbers at SLAP in '03. Both used IB set-ups. Scott said his car "hit harder than OJ and Nicole." That having been said, IB is generally noted as excellent in low-end extension, while AP wins out in transient response. |
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Gold Member Username: Mikechec9Http://www.cardomain.c... Post Number: 2213 Registered: May-05 | And with regard to your curved trunk, Reme actually did something interesting on Unique Whips last week. I turned the channel but word has it that he used something similar to plywood to shape the enclosure without using fiberglass (or perhaps he fiberglassed it in the end anyway. Not certain). On Demand perhaps. |
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Gold Member Username: Mikechec9Http://www.cardomain.c... Post Number: 2217 Registered: May-05 | http://www.caraudio.com/forum/showthread.php?t=139980&highlight=ib+install came across it just now on the humble |
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Gold Member Username: Jonathan_fGA USA Post Number: 5692 Registered: May-04 | "This is still a bit confusing to me, b/c Scott suggests HIGH QTS numbers as being the key to an effective IB sub. He actually employed the UR 12 subs for their stiffness and high QTS. They eventually lossened and he switched to the OA 12's with an even HIGHER Q. So even as the Q dropped due to "break-in," it would still be sufficient enough to use in a huge enclosure. " High Qts is better for IB as far as EBP. High Qts=sealed, IB. Low Qts=small sealed, ported. High Qts subs show more of a peak at Fs, so tend to work better with "looser" enclosures, mainly they're more efficient at Fs than overdamped drivers are. Once you factor in cabin gain, the overdamped drivers tend to give a flatter response, though. I should note that most people don't prefer a flat response (including judges). Most prefer a pretty big jump in low end compared to the rest of the frequency range. Example would be the Lotus References. They posted a 10mm one way x-max via Klippel, but everyone complains that the low extension isn't that good. The problem isn't that they can't play flat (they'll go down to around 40hz flat in a door), it's that they don't have the exaggerated bump in FR around 80hz like other components do. Most systems (even SQ systems) will be tuned to have a 6-10 db jump in low bass output. Most don't prefer flat response, they prefer a smooth response . |
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Gold Member Username: Jonathan_fGA USA Post Number: 5693 Registered: May-04 | Thought they were the Iridiums, though, my bad. |
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Bob365 Unregistered guest | I didn't see Unique Whips, but curved + wood usually means notching (kerf bending) or steam bending. Kerf = Take a sheet of wood then cut a bunch of parallel grooves in the wood with a table saw or router then bend without breaking the outside of the curve then set the inside of the curve with glue or fiberglass, etc. If you do it right you get a nice smooth outside curve. Steam bending is using steam to make the wood flexible and then clamping to a form. |
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Platinum Member Username: GlasswolfWisteria, Lane USA Post Number: 11341 Registered: Dec-03 | or using something like flexible luan. RC esigned his own subs for the setup he used with IB. Not something the average Joe is going to do. He also had a crapload of power fed into them. My biggest problem with IB is how most people try to implement it, which is to say, poorly. They want to use IB to save paying for a box, so they buy some craptacular subs, slap them in a sheet of plywood and shove them behind the bench in a pickup and say, "Hey lok, it's IB!" For IB to work well you want the subs in a sealed area like a trunk so that trunk acts like a big sealed box for the subs. You need to pick the right subs, usually feed them a ton of power, and spend the time to build their baffle properly to se[arate the front from the rear of the subs.. effectively turning your trunk into a box. Even then you lack the control over the response of the drivers you get with a more finely tuned enclosure built to the volume you desire. |
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Gold Member Username: Mikechec9Http://www.cardomain.c... Post Number: 2218 Registered: May-05 | "Even then you lack the control over the response of the drivers you get with a more finely tuned enclosure built to the volume you desire." Yeah. That's the only reason Scott fed 800 watts to each of three subs. |
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Gold Member Username: Mikechec9Http://www.cardomain.c... Post Number: 2221 Registered: May-05 | "Most don't prefer flat response, they prefer a smooth response." Myself included. Flat had to grow on me. Thing is, we're coniderably less able to discern frequencies at that depth. F what sounds good to a machine. If I biologically have audible inadequacies and the means to compensate... compensate |
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Platinum Member Username: GlasswolfWisteria, Lane USA Post Number: 11351 Registered: Dec-03 | but the curve already compensates. that's why we use C weighting and not A weighting |
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