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  • #31
    Originally posted by dlr View Post
    For as long as I've read posts by and had some interaction with Geddes I was never aware that he had worked with line arrays.

    dlr
    Okay thank you for the clarification.

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    • #32
      Originally posted by Pete Schumacher View Post
      The easiest place to hear it is in a car. Cabin gain is obvious to even a casual listener. Close the doors and roll up the windows and the added low end extension is obvious compared to having the doors open. A sealed sub in a closed car can produce some pretty amazing bass. So much for the notion that large rooms are better for bass.
      In most of the systems I've done in cars, I've actually found the opposite to be true- if you're listening with the doors closed and windows up, then open the door, the bass is magnified, not reduced. My current car is a shining example of this (sealed subs).
      "The ability of any system to produce exceptional sound will be limited mainly by the capability of the speakers" Jim Salk
      "Audio is surely a journey full of revelations as you go" JasonP

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      • #33
        Originally posted by mattsk8 View Post

        In most of the systems I've done in cars, I've actually found the opposite to be true- if you're listening with the doors closed and windows up, then open the door, the bass is magnified, not reduced. My current car is a shining example of this (sealed subs).
        Same. Roll the window down a few inches or crack the door open and the bass is much louder. Especially in a small hatchback. I don't know why this is so. I have always felt as if the cabin is possibly acting as a second enclosure, like the second half of a bandpass enclosure and rolling down the window acts as some sort of a vent. My GTi had a dramatic change and simply rolling one window down 3-4" made the bass MUCH deeper and louder.

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        • #34
          Originally posted by make_some_noise View Post

          Same. Roll the window down a few inches or crack the door open and the bass is much louder. Especially in a small hatchback. I don't know why this is so. I have always felt as if the cabin is possibly acting as a second enclosure, like the second half of a bandpass enclosure and rolling down the window acts as some sort of a vent. My GTi had a dramatic change and simply rolling one window down 3-4" made the bass MUCH deeper and louder.
          I think you're spot on. Craig and I were talking about it, and we're thinking the cabin of the car is basically like a bandpass box, and when you open the door you're (theoretically) tuning the box different. Total guess with no science to back it up... but it makes sense . I haven't ever tried it with a ported box, only sealed... curious if the same holds true with ported?? I know a lot of car audio guys are under the impression that ported or horn subs in a car are a waste- I've never experimented with it myself but it's an interesting debate for sure. I don't think I agree that ported in a car is a waste; seems to me like you would [still] be able to dial the bass in better with a ported vs a sealed enclosure in a car. Horns in a car OTOH... seems like a lot of trial and error before you could get it close.

          IMO, cabin gain isn't as cut and dry as it might seem to be.
          "The ability of any system to produce exceptional sound will be limited mainly by the capability of the speakers" Jim Salk
          "Audio is surely a journey full of revelations as you go" JasonP

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          • #35
            I experienced it with sealed, ported, and bandpass boxes. I think a lot of car audio guys dislike the ported or horn boxes because they are so much bigger, and usually with cabin gain and some eq you can get as deep as you need to with a smaller lighter sealed enclosure. In the old days we were always vented or band pass for the most part, but old subs had far less stroke to use..

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            • #36
              Here's my thinking on cabin gain (right or wrong)... There's more to it than just "smaller spaces make bass louder"; I agree that for the most part that's true, but there's another equation somewhere in there as well. My station wagon should be an example of bass gained from "cabin gain"... but for some reason it isn't. The same 2 (sealed) subs I'm running now hit harder in my Saab convertible, and in the Suburban I had them in before the Saab than they do in my current wagon. According to cabin gain, they should hit the hardest in my current wagon... #2 should've been the Suburban... and #3 should've been the Saab- and it was completely the opposite. I want to try ported in my wagon now, because the bass is just weird in it; sometimes it absolutely hammers (Bass Mekanik, Bass Station will make your eyes roll back), and on other tracks it's lack luster at best. So somewhere I'm getting some cancellation in my wagon that I didn't get in the previous 2 cars. I want to try ported to see if I can tune it, but haven't had the ambition to build a bigger box. Or... just throw a DSP at it and never really understand why.
              "The ability of any system to produce exceptional sound will be limited mainly by the capability of the speakers" Jim Salk
              "Audio is surely a journey full of revelations as you go" JasonP

              Comment


              • #37
                Originally posted by make_some_noise
                I experienced it with sealed, ported, and bandpass boxes. I think a lot of car audio guys dislike the ported or horn boxes because they are so much bigger, and usually with cabin gain and some eq you can get as deep as you need to with a smaller lighter sealed enclosure. In the old days we were always vented or band pass for the most part, but old subs had far less stroke to use..
                I still dabble extensively in car audio so i will share my experience, although unrelated to the original topic. With the advent of cheaper amplification (forget discussing merits of class, etc... $ per watt is simply way cheaper nowadays), better build materials (high temp glues, voice coil formers) and the proliferation of inexpensive but very powerful DSP's, car audio has been inundated with high power, low sensitivity, high xmax and low Q subs. Stick one in a small sealed box, feed it with 500+ wrms and use the deck's dsp to EQ it. Bam, you now have a small but super powerful bass machine with ridiculous LFE. Sent from my iPhone using Tapatalk

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                • #38
                  Originally posted by mattsk8 View Post
                  ...There's more to it than just "smaller spaces make bass louder";...
                  I've certainly had vehicles that were better sealed than others, but none were airtight

                  "Not a Speaker Designer - Not even on the Internet"
                  "If the freedom of speech is taken away, then dumb and silent we may be led, like sheep to the slaughter."

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                  • #39
                    Originally posted by mattsk8 View Post

                    In most of the systems I've done in cars, I've actually found the opposite to be true- if you're listening with the doors closed and windows up, then open the door, the bass is magnified, not reduced. My current car is a shining example of this (sealed subs).
                    Interesting. I've always had the opposite experience when running sealed subs in a hatchback. As soon as the door or window opens, the bass drops dramatically. Maybe it's a vehicle dependent bass mode that is shift location when the door or window is open?
                    -Kerry

                    www.pursuitofperfectsound.com

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                    • #40
                      Originally posted by Navy Guy View Post

                      Interesting. I've always had the opposite experience when running sealed subs in a hatchback. As soon as the door or window opens, the bass drops dramatically. Maybe it's a vehicle dependent bass mode that is shift location when the door or window is open?
                      Definitely the case. Physics tells us that being inside an enclosure that is closed would subject us to the highest pressures from a transducer sharing that volume of air.
                      R = h/(2*pi*m*c) and don't you forget it! || Periodic Table as redrawn by Marshall Freerks and Ignatius Schumacher || King Crimson Radio

                      Byzantium Project & Build Thread || MiniByzy Build Thread || 3 x Peerless 850439 HDS 3-way || 8" 2-way - RS28A/B&C8BG51


                      95% of Climate Models Agree: The Observations Must be Wrong

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                      • #41
                        Originally posted by Navy Guy View Post

                        Interesting. I've always had the opposite experience when running sealed subs in a hatchback. As soon as the door or window opens, the bass drops dramatically. Maybe it's a vehicle dependent bass mode that is shift location when the door or window is open?
                        I definitely think that's it. I think it has to do with the car, vs placement (although all the subs in all the cars I listed were rear firing), perhaps the shape of the car... as Sydney said, how airtight the car is or isn't. But to quantify it...? I'll leave that for you guys. And how all this translates into a living room is beyond me, but some of the same effects I hear from subs in a car seem to ring true there too. It is odd to me that you had the opposite effect though.
                        "The ability of any system to produce exceptional sound will be limited mainly by the capability of the speakers" Jim Salk
                        "Audio is surely a journey full of revelations as you go" JasonP

                        Comment


                        • #42
                          Originally posted by philthien View Post
                          Okay thank you for the clarification.
                          I meant that as a statement of surprise, not of fact.

                          dlr
                          WinPCD - Windows .NET Passive Crossover Designer

                          Dave's Speaker Pages

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                          • #43
                            Originally posted by mattsk8 View Post
                            ...perhaps the shape of the car... ....
                            On a related note:
                            Characterization and Validation of Acoustic Cavities of Automotive Vehicles
                            "Not a Speaker Designer - Not even on the Internet"
                            "If the freedom of speech is taken away, then dumb and silent we may be led, like sheep to the slaughter."

                            Comment


                            • #44
                              Originally posted by mattsk8 View Post

                              I think you're spot on. Craig and I were talking about it, and we're thinking the cabin of the car is basically like a bandpass box, and when you open the door you're (theoretically) tuning the box different. Total guess with no science to back it up... but it makes sense . I haven't ever tried it with a ported box, only sealed... curious if the same holds true with ported?? I know a lot of car audio guys are under the impression that ported or horn subs in a car are a waste- I've never experimented with it myself but it's an interesting debate for sure. I don't think I agree that ported in a car is a waste; seems to me like you would [still] be able to dial the bass in better with a ported vs a sealed enclosure in a car. Horns in a car OTOH... seems like a lot of trial and error before you could get it close.

                              IMO, cabin gain isn't as cut and dry as it might seem to be.
                              This is exactly right. A sealed sub in a car is essentially acting as a 4th order bp, a ported sub, a 6th order series tuned bp.
                              Cabin gain does change drastically between vehicles. Its not the same between a honda crx and a Chevy suburban.

                              I havent tried a flh, but have used rlh and th in a suv. Both were very good. Better than ported? Subjective to be sure and larger than most people are willing to live with. But for the bass head (Im in a recovery group myself) it was well worth the spl, kick you in the chest, take your breath away, fun of a monstrosity hammering behind me!
                              https://www.facebook.com/Mosaic-Audi...7373763888294/

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                              • #45
                                Originally posted by dlr View Post
                                For as long as I've read posts by and had some interaction with Geddes I was never aware that he had worked with line arrays.

                                dlr
                                I was talking about Rick Craig and this forum Tech Talk. I was not talking about Geddes.com.

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