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Importance of horizontal dispersion IN MY HOME listening environment....

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  • #16
    Originally posted by ryanbouma View Post
    Are you sure that's an actual 30 degrees? The tweeter top end doesn't look it. Also, whether or not nulls appear depends on the XO points and how steep the crossover slopes are. Sent from my SGH-I337M using Tapatalk
    yes , as close as i could get ... 3rd order at 1850 .
    Paper Towers
    RS180P/28F surrounds
    Boombox

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    • #17
      Based on this information, it wouldn't seem a horizontal arrangement for a center channel speaker would be as bad as some might indicate.

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      • #18
        Originally posted by ryanbouma View Post
        Are you sure that's an actual 30 degrees? The tweeter top end doesn't look it. Also, whether or not nulls appear depends on the XO points and how steep the crossover slopes are. Sent from my SGH-I337M using Tapatalk
        I absoultely beleve those squiggles. However, I wonder the mic distance, too. 1M measurements on speakers that wide do not tell the full story.

        People like to cross tweeters low but typically, as studied by several authors, thermal compression can kick in as low as 5 watts so the curve does not look like that for very long. Always trade-offs...
        .

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        • #19
          all measurement were from 4ft . mike
          Paper Towers
          RS180P/28F surrounds
          Boombox

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          • #20
            Originally posted by filmslayer View Post
            yes , as close as i could get ... 3rd order at 1850 .
            Pretty low crossover with a decent slope. Surprisingly good despite that. My results usually show more comb filtering for a similar situation. I'd post some but they're all on photobucket!!! Haha oh well. Sent from my SGH-I337M using Tapatalk
            https://www.youtube.com/channel/UCm2...oSKdB448TTVEnQ

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            • #21
              Originally posted by philthien View Post
              Based on this information, it wouldn't seem a horizontal arrangement for a center channel speaker would be as bad as some might indicate.
              The low crossover helps. The C2C spacing is good, Don't know about the whole MTM assy width, but if its around 12" the whole thing may be acting like a point source to some degree. Then Dispersion is not that big of a deal.

              Its what I did in the Alpha Cinema Grande. The more I think about it, the more sense it makes, actually, it seems like a pretty smart design from what is given. I was thrown off by the whole spacing, but with a very low x-over like that and a tweeter that certinly can handle it, seems like a heckin Center to me!

              To OPs questions and the orignal thought. Clusters of drivers can be tricky. Most notably tweeters.
              .

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              • #22
                Originally posted by Sydney View Post
                It is done in Live Sound provided that the dispersion characteristics are consistent through out the passband.
                With all due respect(really),

                In live sound, the listening area and place is far different that in a living room in a home with just one or two people in a sweet spot, at one vertical listening position.

                Also, these speakers are not portable. They have to be connected to the electronics of two active crossovers pre channel, a preamp, 6 power amps, and an equalizer. They are built specifically for a certain place.

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                • #23
                  Originally posted by ryanbouma View Post
                  I've used side by side mids in all of the diysoundgroup Cinema speakers. It started with the Elusive 1099. It was very very challenging and that was with a waveguide tweeter. I caution you doing this. Sent from my SGH-I337M using Tapatalk
                  What does very challenging mean? Please be specific as to what were the challenges exactly.

                  Looking at the Elusive 1099 and the discussions on the AVS forum, I would wonder what the crossovers(high and low) were for the 5 inchers, and what their CTC distance is. So I suppose you are not concerned with comb distortion.

                  So, it looks as if you needed to design an extensive and difficult passive cross for this, and I'm not using passive crossovers, and mine are crossed at 24 db. So maybe your concern was the crossover issue?
                  Last edited by malboro2; 09-29-2017, 05:37 PM.

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                  • #24
                    .
                    Last edited by filmslayer; 09-29-2017, 06:01 PM.
                    Paper Towers
                    RS180P/28F surrounds
                    Boombox

                    Comment


                    • #25
                      Originally posted by malboro2 View Post
                      ...Also, these speakers are not portable...
                      My comments were not about your situation, but rather specific interpretation of questions asked by Dynamo
                      "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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                      • #26
                        Originally posted by Sydney View Post
                        My comments were not about your situation, but rather specific interpretation of questions asked by Dynamo
                        Sorry.... Its really hard to stay on task when others hijack the original post and take it in another direction. I understand that its not malicious, but unless the specific information is quoted the OP can get confused as to who is responding to whom.

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                        • #27
                          I think it's the nature of forums
                          ( I've edited my comments fwiw )
                          "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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                          • #28
                            My apologies for the thread derailment, thought it was directly related enough to the op's situation but apparently not. Wasn't intended, I figured the answers would still provide info for the op as well. Thanks for the answers guys.
                            Projects:

                            transcenD: http://techtalk.parts-express.com/fo...5035-transcend
                            Summits: http://techtalk.parts-express.com/sh...75-The-Summits
                            References: http://techtalk.parts-express.com/sh...-My-References
                            Vintage Style 2-way: http://techtalk.parts-express.com/sh...-vintage-2-way

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                            • #29
                              More or less answering the OP's original question: my only negative comment about side-by-side drivers is that lobing sets in at a relatively low frequency. In my case they sound best with a high order crossover (I used LR4 after some experimentation) to get the amplitude down before the lobing gets serious. Otherwise you get some odd imaging. Ask me how I know ;)
                              Francis

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                              • #30
                                Originally posted by malboro2 View Post
                                What does very challenging mean? Please be specific as to what were the challenges exactly. Looking at the Elusive 1099 and the discussions on the AVS forum, I would wonder what the crossovers(high and low) were for the 5 inchers, and what their CTC distance is. So I suppose you are not concerned with comb distortion. So, it looks as if you needed to design an extensive and difficult passive cross for this, and I'm not using passive crossovers, and mine are crossed at 24 db. So maybe your concern was the crossover issue?
                                I'm very concerned with comb filtering and it wasn't a cross over issue. What was difficult was dealing with the erratic off axis comb filtering that is present in side by side drivers. Thankfully you'd be using smaller drivers so that will help, but I still caution you. Ultimately it worked. Erich has sold hundreds of 1099s and it's well liked and measures good, it was just difficult and complex to get there. I also caution to in thinking active crossover will solve the physics problems with such a setup. Considering you've already decided on your crossover slope indicates to me you may not understand that crossover slopes shouldn't be picked arbitrarily. Nothing wrong with slow slopes if they fit the task. I used 1700 hz and 700hz in the 1099. The woofer do have comb filtering unfortunately, it was a compromise I made to achieve other design goals. Which is why I wouldn't tell you to not do it. I only caution you there are pitfalls. The 1099 is only one of a half a dozen or so speaker designs that involve this sort of driver interaction. The 1299 being another very challenging one. I'd share anechoic measurements but photobucket,,, grr. Sent from my SGH-I337M using Tapatalk
                                https://www.youtube.com/channel/UCm2...oSKdB448TTVEnQ

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