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  • #16
    Originally posted by thejash View Post
    I disagree with the sub / sat being sonically better. .
    Explain how you eliminate Allison Effect and low frequency boundary cancellations with floor standers.
    I find the mid-bass region to be extremely lacking on most if not all sub / sat combinations I have heard
    I guess you haven't heard a good one.
    www.billfitzmaurice.com
    www.billfitzmaurice.info/forum

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    • #17
      Originally posted by billfitzmaurice View Post
      Explain how you eliminate Allison Effect and low frequency boundary cancellations with floor standers.
      I guess you haven't heard a good one.
      Like your designs?
      Craig

      I drive way too fast to worry about cholesterol.

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      • billfitzmaurice
        billfitzmaurice commented
        Editing a comment
        Most of them. My David floor stander suffers from the same inherent limitations of not being able to eliminate Allison Effect and low frequency boundary cancellations, a fact that I make no bones about. That's why mine occupies a spot in my workshop, where those concerns are moot, and not in my living room.

      • PWR RYD
        PWR RYD commented
        Editing a comment
        Maybe you should step up your game.

      • billfitzmaurice
        billfitzmaurice commented
        Editing a comment
        If I did manage to rewrite the laws of acoustics by 'upping my game' I wouldn't have to design any more speakers thanks to my Nobel Prize winnings.

    • #18
      Originally posted by JonathanPenner View Post
      Thanks all for the responses. The impression I get is that while a well set up sub/sat system is sonically better, there are other considerations like simplicity and aesthetics that depending on the situation can be more important than the acoustic ideal. Also that a thrown together sub/sat system may sound worse than decent full ranger speakers.

      The crux of it seems to be that to speakers are often in our living spaces and need to fit in them. If a space allows for distributed subwoofers then great, but otherwise the next best thing are some nice full rangers.
      You still imply that a well set up sat / sub setup is better, and full rangers are runners up. I think you are wrong. there's too many other factors controlling sound quality. It's not just about 80hz and down.
      A speaker with a good 10" woofer will sound different than a speaker with a good 6.5" woofer. Although there are diminishing returns, a more expensive speaker is likely to sound better than a more basic speaker. If I was starting from scratch today, building some speakers for music in my living room, I'd probably want to go with a 10" 3-way, and forget the sub.

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      • #19
        rpb for sure, I definitely agree that there's more to sound quality than bass. I suppose my use of the term "satellite" is pretty loose. What I mean is a set of mains designed for 80Hz and up, not strictly a Kleenex box with 3" or 4" drivers. Jeff Bagby's Continuums come to mind.

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        • #20
          Originally posted by JonathanPenner View Post
          rpb for sure, I definitely agree that there's more to sound quality than bass. I suppose my use of the term "satellite" is pretty loose. What I mean is a set of mains designed for 80Hz and up, not strictly a Kleenex box with 3" or 4" drivers. Jeff Bagby's Continuums come to mind.
          I've built a lot of 6.5" 2-ways specifically designed for use with a sub, so I'm not even talking about speakers with tiny 4" woofers. . I have compared distortion in the 80 to 400 range of these drivers with a 10" RS270p. The RS is clearly superior.

          On the other hand, I have a pair of hideously ugly speakers in my HT room. ( Peerless 5.25" HDS GFC 2-ways with sloped baffles, and large round overs. They have been altered dozens of times) . I use them with a 15" sub in 7 cu-ft box. I've wanted to replace the baffles to make them look good, but I have concerns that the sound might change, and right now they are my favorite speakers.

          I have on occasion compared this system with whatever I'm playing with in the living room. My neighbor and I have a slight preference for the HT system. My other friend has no preference. Neither of them would be good judges of quality though.

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          • #21
            Originally posted by JonathanPenner View Post
            I keep reading that the ideal place for subwoofers is rarely beneath mains due to how low frequencies behave in rooms. It got me wondering, if the issue is about frequencies where the room is acoustically small, what are the advantages of building towers and larger speakers that produce those low frequencies if those frequencies are better suited to be played by multiple distributed (sub)woofers? Instead of building a three- or four-way tower, should the default decision instead be bookshelves and multiple subwoofers crossed at 80Hz to get an even in-room response?
            You would seem to be generalising way too much. If you have only 2 subwoofers operating below 80 Hz, mains that can produce clean SPL down to 80 Hz (satellites are often deficient in this respect), interested in sound quality for music and the subs have full control over gain and phase (home susbs are often deficient in this respect) then placing the subs below the mains is unlikely to be the best option. A better one would is likely to be one sub in the centre of the front and one in the centre of the back wall.

            Optimum solutions in other circumstances will be different. If your towers are full range then they can provide 2 of the distributed subs. If your satellites are small and cannot reproduce 80 Hz cleanly then addressing this may bring more benefits than subs. If... the wretched forum software is continually interrupting with a server error popup and so I will give up typing at this point.

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            • #22
              Here's an interesting talk - to me, anyway - on the subject of bass with floor standers c/w stand mounted speakers with a sub. The presenter is Harley Lovegrove, Technical Director of Pearl Acoustics loudspeakers. He's also a musician and recording engineer.

              He discusses bass reproduction in recordings of Beethoven and Lou Reed and has some ideas on blending the sub to the system.

              https://www.youtube.com/watch?v=c3EL7OBi5Gw

              Geoff
              Last edited by Geoff Millar; 11-11-2021, 06:16 PM.

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              • #23
                Originally posted by andy19191 View Post
                placing the subs below the mains is unlikely to be the best option.
                It's not just unlikely, it's almost impossible.There's optimal placement for low frequency sources and optimal placement for higher frequency sources. The only circumstance where they're one and the same is outdoors, or in the center of a room so large that it might as well be outdoors.

                A better one would is likely to be one sub in the centre of the front and one in the centre of the back wall.
                That would be better than both subs in the front of the room, though not necessarily the best placement for a given room, as all rooms are different. But there's no question that having both low frequency sources in the front of the room is usually the worst placement option, and when the low and high frequency sources are in the same enclosure that's the only option available.
                www.billfitzmaurice.com
                www.billfitzmaurice.info/forum

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                • #24
                  Originally posted by billfitzmaurice View Post
                  Explain how you eliminate Allison Effect and low frequency boundary cancellations with floor standers.
                  I guess you haven't heard a good one.
                  The increase in distortion from a single small 6.5 inch woofer will drastically outweigh the negatives of the Allison Effect unless you have a tiny room and / or listen at low volume, neverminded the possibility of damaging the woofer.

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                  • billfitzmaurice
                    billfitzmaurice commented
                    Editing a comment
                    I never said anything about using a single small 6.5 inch woofer, although the fact of the matter is that there are many single 6.5 inch loaded mains that are quite capable of more than adequate output with very low distortion when crossed over at 80 to 100Hz.

                • #25
                  Originally posted by billfitzmaurice View Post
                  Explain how you eliminate Allison Effect and low frequency boundary cancellations with floor standers.
                  I guess you haven't heard a good one.
                  Since you're being technical, technically your statement is redundant, "the Allison Effect" and "low frequency boundary cancellations" both relate to the same thing. I'll add that while a separate subwoofer might help alleviate room issues, it won't "eliminate" them.

                  As to the OP, I prefer a large floor stander for 2 channel music (in spades) over a stand mount with a subwoofer. For HT a satellite system is tough to beat. "High fidelity" is a game of compromises, and this will depend on a lot of factors (mainly your room and what your significant other will allow in that room).

                  I don't think there is a blanket answer to your question, one isn't necessarily better than the other. The room will largely dictate that answer. Bill will disagree because he wants to sell you his plans.
                  "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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                  • billfitzmaurice
                    billfitzmaurice commented
                    Editing a comment
                    Allison Effect, as explained to me by Roy Allison, is the meeting of the direct wave and the wave reflected off the wall behind a speaker, resulting in a cancellation when the waves meet a half wavelength apart. Depending on the distance to the wall it can be a low frequency cancellation, but it can occur at any frequency below the baffle step. Low frequency boundary cancellations can occur off any boundary in the room, including the floor and ceiling, and are determined by the relative positions of the sources, the boundaries and the listening positions. The most effective way of controlling them is to use more than one low frequency source placed as required to result in as smooth a response as possible at the listening positions. This has nothing to do with my plans. The laws of acoustics apply equally to all speakers.

                  • mattsk8
                    mattsk8 commented
                    Editing a comment
                    So do the laws of diminishing returns. I stand by everything I said, Yoda. I disagree with your (condescending) replies here. And you're still wrong, adding external subwoofer(s) doesn't "eliminate" the Allison Effect, it alleviates it.

                • #26
                  All that said... "Is a system with an external subwoofer better" might be a better question. I would still prefer a large floor stander with a sub, but a properly integrated subwoofer is tough to beat. I don't use one on my music system because to me it's like adding N2O to a car, it's less impressive than a large 3 way that covers the entire bandwidth. But that's my opinion.
                  "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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                  • #27
                    I would be interested to know if there are ever concerns about the pressure created by a close proximity woofer in a 3-way damaging a sensitive tweeter under the right circumstances.

                    Comment


                    • mattsk8
                      mattsk8 commented
                      Editing a comment
                      At the SPL needed to make this a possible reality, I think any tweeter that might be susceptible to something like that would be on fire before this became a reality.

                    • fpitas
                      fpitas commented
                      Editing a comment
                      Most likely you'll be deaf soon enough, so who needs a tweeter?

                  • #28
                    A) if you’re going to use stands, why not make use of dead space under the speaker? Go with a tower.
                    B) at the frequency below the excursion limited SPL, a bigger Sd will be better. Less cone movement less distortion.
                    this is why that all important area below 262-300Hz is better covered by a 10” woofer than 5” woofer. And why a high sensitivity 15” woofer is better than a 10” woofer.
                    C) but achieving a crossover at 300Hz is hard to achieve if your Woofer is halfway across the room.

                    I think a large speaker that does 40Hz-20Khz is plenty for music.

                    for Home theatre integrate a LFE channel which contains; by definition, +10 dB greater output than the mains, for frequencies below 120Hz.
                    uf you’re listening alone, you only need one subwoofer. If you’re aiming for relatively smooth bass response throughout the room for multiple listeners, then scattered subs work better.

                    I have a 3 way WMTM crossed over at 120hz by design, and external W also running at 120H scattered about the room. So four woofers running under between 30-120Hz…

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                    • mattsk8
                      mattsk8 commented
                      Editing a comment
                      Well said. As for #1, if you're using the "real estate" anyhow, you might as well make the best of it.

                  • #29
                    Well, I see it's really "it depends" and I'm trying to find a general solution to problems with a lot of nuance. To clear up mid-bass distortion it's likely a large woofer is needed, which usually will lead to floor standers anyway. If that on its own works well for music at the listening position (and what the listener can hear) then adding a subwoofer may only have a minimal effect, in addition to all the aforementioned reasons of rooms and living situations being different. Certain tradeoffs are going to have different priorities depending on the person.

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                    • billfitzmaurice
                      billfitzmaurice commented
                      Editing a comment
                      You don't necessarily need a larger woofer. Model your proposed mains midbass driver. If it provides the output you're looking for without approaching either Pe or Xmax it's large enough. If not, use two in an MTM. Or use more. My L/R mains are loaded with four inch midbasses, eight per side in a line array, with insignificant THD at 110dB.

                      When you have a full range speaker unless you flush mount it in the wall you will have a cancellation. That's not negotiable. You need to be familiar with this:
                      http://arqen.com/acoustics-101/speak...-interference/

                      It's a good article as far as it goes, but it doesn't go far enough. What it doesn't mention is that the same cancellations are sourced in the same manner off the wall behind the listening position, and off the side walls, floor and ceiling. The cure is to use multiple subs spread around so that they don't excite the same cancellations.

                  • #30
                    Another factor to mull is that a bass driver colocated to the satellite (a "tower") can be crossed higher than the 80-100hz that a separate bass driver needs to remain under the threshold of sound location.

                    I've had one or two subwoofers in my living room for as long as I could afford them. But that's mainly AVR driven 5.1 HT use. I listen to most music on my powerful PC 2.1 system, and occasionally on my (2.1) LXminis in the living room.

                    I was quite happy with my Carmody DIYSG S2000 MTM L/C/R, (4" woofers) but I just love building speakers so now I have cjd RS150 MTMs for L/C/R.

                    I have numerous MT pairs (really) for my PC system, currently using SR71s or Continuums.

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