Announcement

Collapse
No announcement yet.

2-way versus 3-way designs: Some thoughts from Iowa DIY 2008

Collapse
X
 
  • Filter
  • Time
  • Show
Clear All
new posts

  • 2-way versus 3-way designs: Some thoughts from Iowa DIY 2008


  • #2
    Re: 2-way versus 3-way designs: Some thoughts from Iowa DIY 2008

    I can personally say that getting the correct voicing on a 3 way is a bit more difficult than it is on a two way. With the two way, most of the time the crossover point is somewhere in the middle of the upper midrange region, and that may lend itself better to getting that "less forward" sound. I found with voicing of my Purple Puppies for a long time, making change after change until I felt I had the right combination of fullness, yet clarity and detail in the vocal regions...without forwardness....and for a while, I thought I never would get it to that "just right" place.
    I have heard several 3 ways and that is one aspect I always thought about as well...the upper mids seemed a bit too forward compared to the lower octaves....like there was a bit of an imbalance going on. Not sure where the problem really lay, since I didn't have access to data (measurements, etc) on any of them. I can pretty much guess that there was either a mismatch of midrange level with bass level, or not enough taper on the upper region of the midrange before crossing to the tweeter, OR too much overlap going on.....something like that.

    John
    If it doesn't fit right the first time, you obviously need to use a larger hammer. :p

    Comment


    • #3

      Comment


      • #4
        Re: 2-way versus 3-way designs: Some thoughts from Iowa DIY 2008

        Well, Jon, I've come to the conclusion that the sound is more a function of design and time spent reaching voicing preferences than any topology.

        In general though, I've come to an opinion that a well excuted 3-way will be more likely to capture the emotion of more kinds of music, maybe because drivers are doing less in a more effortless manner.

        There are several things I think make make big differences - leading to some wild generalizations - some below. All may be, without offending, judged the ravings of a man without a clue.

        Here goes:

        Most importantly, to get speakers that deliver music - much more time (many months) should be spent listening and voicing rather than designing / modeling / shuffling bits on the computer.

        Either 2-way or 3-way can exhibit either general character you have described.

        Unless done by one of the few masters, hugely complex XO's usually suck the soul from a speaker and leave it lifeless and compressed sounding. I think maybe modelling makes it too easy to chase every anomoly and not listen.

        The vocal range of maybe 300-3000 is critical. Frequency response and driver integration over that range is an important factor in the overall character of the speaker, obviously, esp voices. Most speakers have a crossover in there somewhere, almost certainly in the case of a 2-way.

        Whichever drivers cover that area should be running in thier sweet spot for most effortless sound. You can't make a driver go where it does not want to go.

        A dip in the middle of that range makes voices sound a bit laid back, warmer, and more intimate, flat or a misplaced peak is more likely to sound a bit more forward.

        For me, the preference runs toward poly / paper / fabric for warmth, and away from metal/kevlar. Years of designing mostly by ear teaches me I can't execute metal or kevlar worth a damn - even with modelling. The softer cones are easier to work with - for me - and a better way to spend X $ and time resources.

        The likes of Curt C or Dennis Murphy or Jeff Bagby can build with anything and always seem to pull off superior stuff. They must have struck some deal with the dark side of the force or something. How's that for a technical explanation for success?

        MG

        Comment


        • #5
          Re: 2-way versus 3-way designs: Some thoughts from Iowa DIY 2008

          Did you feel the 3-way I brought was forward as well? I'm really curious about this. It involved a metal-mid, so it might not have been as smooth as a silk/paper mid. I did hear a lot of positive results/statements from people commenting on them.
          Later,
          Wolf
          "Wolf, you shall now be known as "King of the Zip ties." -Pete00t
          "Wolf and speakers equivalent to Picasso and 'Blue'" -dantheman
          "He is a true ambassador for this forum and speaker DIY in general." -Ed Froste
          "We're all in this together, so keep your stick on the ice!" - Red Green aka Steve Smith

          *InDIYana event website*

          Photobucket pages:
          http://photobucket.com/Wolf-Speakers_and_more

          My blog/writeups/thoughts here at PE:
          http://techtalk.parts-express.com/blog.php?u=4102

          Comment


          • #6
            Re: 2-way versus 3-way designs: Some thoughts from Iowa DIY 2008

            that makes sense.

            you might be used to having a hole in the power response around 2 khz from over-stretching a midbass.

            Comment


            • #7
              Re: 2-way versus 3-way designs: Some thoughts from Iowa DIY 2008

              Originally posted by vasyachkin View Post
              that makes sense.

              you might be used to having a hole in the power response around 2 khz from over-stretching a midbass.
              You've got a point, but not due to overstreching a midbass as much as the topology most two ways utilize. LR4 is very popular and lends itself to simple XOs producing a flat response in the XO range. But the power response of the LR4 is not flat in the XO region, but dips approximately 6dB. That difference might be what some hear as well, since power response is quite important when used in anything other than an anechoic chamber.

              A three way, like Paul K's Centilanas, has a very flat power response in comparison with most two ways, which would, relatively, have more output in the upper midrange from a power response perspective.

              Dennis Murphy mentioned something similar when he was testing a SEAS co-axial 7" woofer/1" tweeter a while back. The typical LR4 alignment didn't quite sound the same as a system with non-coincident drivers. The coax doesn't have the same issue with power response as separate drivers in LR4 alignment.
              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
              "Gravitational systems are the ashes of prior electrical systems.". - Hannes Alfven, Nobel Laureate, Plasma physicist.

              Comment


              • #8
                Re: 2-way versus 3-way designs: Some thoughts from Iowa DIY 2008

                Originally posted by jonw View Post
                Unfortunately, I have no idea which version of her voice is correct.
                It's an inherent problem that comes from using studio recordings as the source in listening tests. There is no reference to which to compare.

                It would not be all that difficult to have some real live performers at such events, and use unprocessed recordings of them for the comparison tests. Even a simple recording of someone speaking would tell more about loudspeaker accuracy than all the overproduced commercial recordings put together . . .
                "It suggests that there is something that is happening in the real system that is not quite captured in the models."

                Comment


                • #9
                  Re: 2-way versus 3-way designs: Some thoughts from Iowa DIY 2008

                  You've got a point, but not due to overstreching a midbass as much as the topology most two ways utilize. LR4 is very popular and lends itself to simple XOs producing a flat response in the XO range. But the power response of the LR4 is not flat in the XO region,
                  There is also the tendency in two-ways to cross over too high, which not only puts signal on the woofer in its breakup region but also (commonly) drives it well into the region where it is beaming. That results in a significant and relatively abrupt change in the polar at crossover, compounding any other power response issues. This problem can be substantially avoided in controlled directivity speakers (dipole and omni), which may account for some of their "naturalness".

                  Lots of three-ways share that problem, of course, crossing their mid drivers too high for the size of the cone, but the effect may be less noticible at higher frequencies.
                  "It suggests that there is something that is happening in the real system that is not quite captured in the models."

                  Comment


                  • #10
                    Re: 2-way versus 3-way designs: Some thoughts from Iowa DIY 2008

                    Jon,

                    I think what you are hearing is simply different than what you are used to. For example, I did a lot of music listening to choose my music selections. I did this on headphones at work. The headphones were on the hot side. My ears soon adapted and after selecting the music, I auditioned them on all my speakers. They all sounded very dull and laid back. I realized what had happened and gave my ears a few days (sans headphones) to adapt to the sound of my speakers again and they eventually sounded balanced and natural again.

                    IMO, you are used to listening to a 2way. They often seem to have a bit more recessed midrange, IMO. I think this happens because as you voice the system, you tend to adjust out any strain or try and reduce the prominence of the sections where the driver is being pushed too hard. This often ends up being at the low end of the tweeter and high end of the woofer, say in the 1500-2000hz area. For a 3way, however, this is the midband of the midrange driver in many cases.

                    Also, I would guess that most drivers, at the edge of their sweetspot are perhaps losing some clarity, especially in a 2way, since it stretches drivers further. What you may be hearing in the 3ways is more clarity in the mids, making them sound more prominent. Certain midranges do have a more prominent sound for one reason or another, possibly due to what they are made of.

                    Remember, you are also used to hearing the Scan paper sound, which is very smooth and easy on the ears. That is probably one reason why you liked the Duo-S.
                    Dan N.

                    Comment


                    • #11
                      Re: 2-way versus 3-way designs: Some thoughts from Iowa DIY 2008

                      After hearing Paul's speakers, I mentioned this forward midrange sound to Paul at the break and he agreed. He told me after the lunch break that he had his speaker measured at the break and it measured flat.

                      Then, towards the end of the day, I heard the two ZDT3s and thought they had the same forward type of midrange. It was not unpleasant, just different. However, all three speakers used the same midrange driver, the RS52. By the way, I did not notice this with Ben's (Wolf's) three way.

                      I wondered if there was something about the venue that may have caused this? Is it possible that in the auditorium, the size of the room swallowed the base, allowing that particular midrange to become more noticable? Or is it possible that the RS 52, due to its shape or design caused it to sound more forward in a large venue?

                      Maybe the designers will spot this thread and come in and comment. I'm hard pressed to believe that Paul wouldn't have noticed this prior to Iowa, and yet feel concerned enough about it there that he would have his speakers measured to see if they were flat.

                      Comment


                      • #12
                        Re: 2-way versus 3-way designs: Some thoughts from Iowa DIY 2008

                        Just read Dan's post. I didn't think about the musical selection. I think Dan may have a point, too.

                        Comment


                        • #13
                          Re: 2-way versus 3-way designs: Some thoughts from Iowa DIY 2008

                          I suspect that the majority of people are used to and prefer the classical type bbc dip. Most people I know scoop the mids when they see an eq.

                          I have a pair of flat studio monitors and I find most listeners prefer that I EQ a little mids out of the equation.(2.5k center).

                          My first 2 way MTM center speaker design came out sounding pretty good. But, when I RTA measured the freq response I found a 2khz dip. I had some buyout polk speakers with a LR4 centered at 2600hz. I prefer to shoot for an linear FR so I changed a cap on the woofer to extend it's reach and consequently filled the hole. I suspect that the tweeter was working outside of its range and rolled off a little early.

                          I am happy with the way it sounds. I feel like the change in the cap makes it a little easier to make out what people are saying when listening to movies. Before I had to turn the whole system up to compensate for this.

                          Comment


                          • #14
                            Re: 2-way versus 3-way designs: Some thoughts from Iowa DIY 2008

                            I also received some comments that the Tzu-jan midrange was a bit forward, but it also measures flat.

                            Comment


                            • #15
                              Re: 2-way versus 3-way designs: Some thoughts from Iowa DIY 2008

                              I wonder how much deviation the different measurement techniques could be attributing to the probelm.

                              Assuming that all other items remain constant. Perhaps pink noise would produce significantly different results than a sine sweep....

                              Comment

                              Working...
                              X