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What's the highest sensible crossover point for a 2.1sub/sat system?

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  • What's the highest sensible crossover point for a 2.1sub/sat system?

    I've not been able to find much advice on this. I'm looking to experiment with some fairly tiny satellite speaker designs. Is 200Hz way too high, and does it depend on where you locate the sub?

  • #2
    Above 100 hz you can locate the sub, that's general opinion.

    Comment


    • #3
      Ah, interesting. It seems a lot of commercial "lifestyle" systems push it higher than that. I guess that's the consumer market for you.

      Comment


      • djg
        djg commented
        Editing a comment
        Well, if you're doing a desktop 2.1 and you put the sub in front of you, it may be fine. Down on the floor, maybe not.

    • #4
      Yes the original Bose Accoustimas system even had a hole in it's response, the "bass module" only went up to about 200-225hz but the cubes didn't come in until 275hz or something so there was an actual notch in the response that was demonstratable with a tone sweep.

      If you do this and run your sub up to whatever it needs to go to then it will work, but yes it will then stand out and shout "look at me". However this isn't any different than how a 3-way speaker system would behave so it may not be that big a deal, you may just need to adjust expectations.
      Paul O

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      • #5
        The highest cutoff point is also dependent on the rolloff at higher frequencies. The bog-standard "80 Hz" is dependent upon a 12dB/oct LP rolloff. Go for a high rolloff, and you can use a higher cutoff frequency.
        Brian Steele
        www.diysubwoofers.org

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        • #6
          Originally posted by zx82net View Post
          does it depend on where you locate the sub?
          It does. If the subs are below the mains there's no more problem going to 200Hz or higher than if you have a typical large woofer three-way cab. But if you do that then you can't locate the subs where they work best and the mains where they work best, which is seldom if ever within the same footprint. Having that ability is the reason why the separate sub/satellite configuration was invented.

          www.billfitzmaurice.com
          www.billfitzmaurice.info/forum

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          • #7
            I'm thinking here of siting the sub pretty much in the middle of the stereo pair, so maybe it'll be workable. I guess I should do some experiments trying a 200Hz crossover with some more normal speakers before actually building some micro-sat's.

            Interesting what Paul said about the original Accoustimas, amazing what marketing will let you get away with. Perhaps they had some research to show 90% of the worst notes in music lie between 225 and 275Hz.

            Comment


            • #8
              We don't know what you mean about "fairly tiny" or how loud you intend on playing it. So the answer is " it depends" on your needs. What drivers did you have in mind? What is the environment? Background music, serious listening, HT? How low do you need to go? How far apart are you talking? Just to the side of the screen? I once saw an idea where the tv sat on a box with an 8 sub firing out each end, centers facing you and small sats just to the side of the screen.

              Testing is always an excellent idea. Pick music like a Jazz bass solo where there is not as much masking from the mids to fool you.

              Personally, I would not look at Bose distortion generators as a source for design.

              Comment


              • #9
                Originally posted by zx82net View Post
                I'm thinking here of siting the sub pretty much in the middle of the stereo pair
                Why? Because it looks good there? Because it's convenient there? Because you wife will let you put it there? Those are the three worst reasons for sub placement. It should go where it sounds best.
                Interesting what Paul said about the original Accoustimas, amazing what marketing will let you get away with. Perhaps they had some research to show 90% of the worst notes in music lie between 225 and 275Hz.
                The sub was band pass, which limited how high it could go. They used midbass drivers that couldn't go low enough to keep the box size small enough for WAF, with no regard to how they sounded.
                www.billfitzmaurice.com
                www.billfitzmaurice.info/forum

                Comment


                • #10
                  Originally posted by tvrgeek View Post
                  We don't know what you mean about "fairly tiny" or how loud you intend on playing it. So the answer is " it depends" on your needs. What drivers did you have in mind? What is the environment? Background music, serious listening, HT? How low do you need to go? How far apart are you talking? Just to the side of the screen? I once saw an idea where the tv sat on a box with an 8 sub firing out each end, centers facing you and small sats just to the side of the screen.

                  Testing is always an excellent idea. Pick music like a Jazz bass solo where there is not as much masking from the mids to fool you.

                  Personally, I would not look at Bose distortion generators as a source for design.
                  I have the Tectonic 1-1/8", 2" and 3", I'm going to play about with each of them and see what I get.
                  The sub, again, I've got some choice, I've got a Tang Band T2-2181SA and a couple of different subs I built based on the Tang Band W3-1876S, so we are not exactly talking ground shakers here.

                  Luke
                  Tang Band T2-2181SA 2" Subwoofer Module 6-7/8" x 2-3/4"

                  Comment


                  • #11
                    Originally posted by billfitzmaurice View Post
                    Why? Because it looks good there? Because it's convenient there? Because you wife will let you put it there? Those are the three worst reasons for sub placement. It should go where it sounds best.
                    The sub was band pass, which limited how high it could go. They used midbass drivers that couldn't go low enough to keep the box size small enough for WAF, with no regard to how they sounded.
                    No, because this is for my office and if I put it on the floor I'll probably kick it on a regular basis, but I have room to stick it behind my monitor.

                    Luke

                    Comment


                    • #12
                      Based on desktop use in front of a computer with the sub in close proximity to the mains, the ability to audibly locate the sub isn't as critical as it would be in a large room HiFi system. A 200Hz crossover point is easily doable for your little desktop system IMO.
                      Electronics engineer, woofer enthusiast, and musician.
                      Wogg Music
                      Published projects: PPA100 Bass Guitar Amp, ISO El-Cheapo Sub, Indy 8 2.1 powered sub, MicroSat, SuperNova Minimus

                      Comment


                      • #13
                        AH HA, desktop, nearfield. OK, sounds more do-able. I run FE85's but there are a couple of better choices that reach down to 85 or so easily. Add a small tweeter and pretty small sats are possible.
                        I was going to make an 8 inch sub and mount it under the desk, but never got around to it.

                        I woudl not play games with wired modules like that TB T2 thing. Bass requires moving air. With careful driver selection, you can probably get mid -50's in a box small enough to sit behind the monitor from the smaller traditional subs. Something like this:https://www.parts-express.com/tang-b...eaker--264-917. Actually, I might think about one.

                        Comment


                        • #14
                          So you basically need a small mono bass unit to sit on your desk to cover 200Hz down to something reasonable (maybe 50/60/70Hz (ish)) on the 0.1 output of a modest 2.1 amp (?)

                          I would use the Tang Band W3 you mentioned in post #10; or to save money use a $26 Dayton ND91-4 (290-224) in the box size (0.4 cu ft) and tuning used in the Helium speakers; or a cheaper ($12.50) for TCP115-4 in a bigger box.

                          The W5 tvrgeek linked is really popular in the "Voxel" subwoofer designed by Paul Carmody but would be too big for my desk. Mounting underneath might work (not on my desk) but it would be way more near-field bass than I would need or want.

                          Comment


                          • #15
                            Originally posted by a4eaudio View Post
                            So you basically need a small mono bass unit to sit on your desk to cover 200Hz down to something reasonable (maybe 50/60/70Hz (ish)) on the 0.1 output of a modest 2.1 amp (?)

                            I would use the Tang Band W3 you mentioned in post #10; or to save money use a $26 Dayton ND91-4 (290-224) in the box size (0.4 cu ft) and tuning used in the Helium speakers; or a cheaper ($12.50) for TCP115-4 in a bigger box.

                            The W5 tvrgeek linked is really popular in the "Voxel" subwoofer designed by Paul Carmody but would be too big for my desk. Mounting underneath might work (not on my desk) but it would be way more near-field bass than I would need or want.
                            I'm actually working on a Voxel, but not for this, like you say, a bit big for a desk. I designed and built this, which is a remix of a Hexibase design. It's actually rather well suited to desk use, because the vibration output is practically nil.
                            Download files and build them with your 3D printer, laser cutter, or CNC. Thingiverse is a universe of things.

                            Comment


                            • ceiol
                              ceiol commented
                              Editing a comment
                              very cool build! what's the height? about 1 foot?

                            • djg
                              djg commented
                              Editing a comment
                              Cutesy indeed, lol. Very cool look.

                            • zx82net
                              zx82net commented
                              Editing a comment
                              About 1.5 ~ 2 foot, depending on which combination of port styles you use.
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