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  • Buyout Vifas for line array?

    Hey guys. How would the Vifa TC9FD-05-16 3.5 inch full range drivers do in a line array? I was thinking about building them to fit in the front left and right corners of my church. Have about 24 per side. At 6 bucks a piece, even I could afford these!
    The Past is history. The Future is a mystery. Today is a gift; that's why its called the Present. (Grand Master Oogway, Kung Fu Panda)

  • #2
    Re: Buyout Vifas for line array?

    Sensitivity is fairly low, and that's a 1 watt rating in a 16 ohm speaker (not 2.83v) . Even with 24, could be a stretch depending on how large a space it is. Power handling is low, but with 24 it would come up to 240 watts a side, seems acceptable to me. And then there is the matter of wither they will go low enough to cross to something larger (fs = 115hz), and the fact that they include a cap to X-over at 200Hz suggests something. Perhaps 100Hz in doable with 3rd order. That being said, I bet they would do a great job of vocals. Question would be, for $288, is there something better? How would the $16.00 Dayton Audio PA165-8 6" PA Driver work? your could put 9 per side at the same cost, and I bet they would work better, have good sensitivity, and would drop to that 100Hz mark.

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    • #3
      Re: Buyout Vifas for line array?

      If the idea was to run 24 per side w a 3 5/16" driver spacing w/o shading:
      That would be a 2M line and could be wired to 6 ohms.
      Without tweeters: The driver spacing limits HF coherence to below 4Khz.
      The nearest audience member should be no nearer than 50'
      Last edited by Sydney; 03-14-2011, 05:12 PM.
      "Not a Speaker Designer - Not even on the Internet"
      “Pride is your greatest enemy, humility is your greatest friend.”
      "If the freedom of speech is taken away, then dumb and silent we may be led, like sheep to the slaughter."

      Comment


      • #4
        Re: Buyout Vifas for line array?

        I've thought along similar lines and bought 4 of the Vifa's for testing when they were a little more expensive.

        I have 3 of them wired in parallel for a 6 ohm load and in a cardboard test box in front of my computer. The 3 of them are together are about as loud (by ear) as a single JVC 3X5 speaker that was on closeout at PE. I bought the JVC's in the classified sections, after already purchasing the Vifa's and considering how much work there would be making roughly 3 times the number of holes of Vifa's than for the JVC's for about the same sensitivity.

        My former church used 4 of the Bose L1 line arrays and I thought they sounded pretty good for vocals and moderate volumes -- though I normally think of Bose as very overpriced and mediocre. Vocals and acoustic guitar sound very good through the Bose, better than many PA speakers I've heard at churches -- but I still think the L1's are way overpriced.

        On the plus side, I some research on line arrays and former McIntosh designer Roger Russell is supposed to make some very good line arrays for home use. His speakers are supposed to use Vifa full rangers as well, see below for a link. So I think the Vifa's on closeout have potential. But no matter what, you'll need separate woofers to produce the midbass for a PA, let alone the deep bass.

        http://www.ids25.com/
        http://www.parts-express.com/pe/show...umber=264-1064

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        • #5
          Re: Buyout Vifas for line array?

          Originally posted by bbtk View Post
          former McIntosh designer Roger Russell is supposed to make some very good line arrays for home use.
          sort of makes me wonder what he did about the comb filtering, as his seem to be 4 or 5inch drivers. He says there is NO crossovers...

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          • #6
            Re: Buyout Vifas for line array?

            From http://www.roger-russell.com/equalizers/equalizers.htm
            "The IDS-25 system is also equalized and the curve is unique to complement the specific drivers used in the system...The wide-range drivers are all connected in series parallel...the equalizer smooths response and extends both low and high ends of the spectrum...The system is based on my patents and earlier work with equalizers and column systems"

            Roger Russell has written numerous articles in AudioAmateur mag. and his systems and EQ are not simple - reflected by $18K+ price.
            "Not a Speaker Designer - Not even on the Internet"
            “Pride is your greatest enemy, humility is your greatest friend.”
            "If the freedom of speech is taken away, then dumb and silent we may be led, like sheep to the slaughter."

            Comment


            • #7
              Re: Buyout Vifas for line array?

              I think you would do better with some of the buyout Aurasound drivers over at www.madisound.com for a line array....

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              • #8
                Re: Buyout Vifas for line array?

                https://www.madisound.com/store/manu...525-255-8a.pdf
                These are 5.25 and run $3.60 each. They have two others there ranging from $2.50 - $4.50 with very similar TS to the Vifas you're looking at.
                Just food for thought. I have played around with several of the NRT small drivers from Madisound and they are quite good.

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                • #9
                  Re: Buyout Vifas for line array?

                  Originally posted by Sydney View Post
                  From http://www.roger-russell.com/equalizers/equalizers.htm
                  "The IDS-25 system is also equalized and the curve is unique to complement the specific drivers used in the system...The wide-range drivers are all connected in series parallel...the equalizer smooths response and extends both low and high ends of the spectrum...The system is based on my patents and earlier work with equalizers and column systems"

                  Roger Russell has written numerous articles in AudioAmateur mag. and his systems and EQ are not simple - reflected by $18K+ price.
                  I understand the concept, first used in the Bose 901 for the same reasons, but I don't see how that would help with the comb filtering. And considering what a quality DSP unit costs, it hardly would justify that kind of price.
                  Last edited by AMC; 03-17-2011, 12:48 PM.

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                  • #10
                    Re: Buyout Vifas for line array?

                    Originally posted by AMC View Post
                    How would the $16.00 Dayton Audio PA165-8 6" PA Driver work? your could put 9 per side at the same cost, and I bet they would work better, have good sensitivity, and would drop to that 100Hz mark.
                    The 6" drivers would not be a good solution unless separate smaller HF drivers are used. The 6" drivers by themselves will have center-to-center spacing that is too great to function as a line array in the upper midrange and treble.

                    I'm not sure why people are naysaying the 3" drivers, when that seems to be the preferred solution among pro audio manufacturers who are actually manufacturing line arrays. To fill in the midbass range, either run stereo subwoofers with a high crossover point (200 Hz or so) or provide midbass modules with something like four beefy 6" woofers, like these: Goldwood heavy-duty 6"

                    In a midbass module, a couple of these would be an even better solution.
                    Best Regards,

                    Rory Buszka

                    Taterworks Audio

                    "The work of the individual still remains the spark which moves mankind ahead, even more than teamwork." - Igor I. Sikorsky

                    If it works, but you don't know why it works, then you haven't done any engineering.

                    Comment


                    • #11
                      Re: Buyout Vifas for line array?

                      Originally posted by Taterworks View Post
                      I'm not sure why people are naysaying the 3" drivers, when that seems to be the preferred solution among pro audio manufacturers who are actually manufacturing line arrays.
                      Even the big ones with 12" woofers will have a couple of 3" (or four) per element (plus a tweeter). The one in the JBL pro units might even be 2".....

                      In a midbass module, a couple of these would be an even better solution.
                      For 60Hz-up bass, four of those might be preferred to a single fifteen. And if you really wanted to get crazy, that particular 8" would work very well as the bottom end of a 3-way line array.

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                      • #12
                        Re: Buyout Vifas for line array?

                        Not naysaying, just acknowledging the compromises: driver size/spacing sets the HF limit and directivity, displacement limits of drivers.
                        There is not a lot of internal detail on the IDS-25s array, only very simple FAQ and sales oriented type.
                        I suspect that while no crossovers are used: that the internal series/parallel wiring could be similar to concepts employed in Bessel arrays to perform amplitude shading ( Keele's paper details numerous passive wiring schemes that include resistors. )

                        I don't see how that would help with the comb filtering.
                        If however the drivers are treated uniformly: then I'm of the same opinion.
                        Smaller transducers raise the HF limit, but not to upper limit of audibility ( w/o tweeters ), and require large numbers be used for excursion and power handling requirements; and can create wiring challenges or require high impedance drivers or an autotransformer be used to maintain an amp friendly stable load.
                        In general in professional arrays ( as used in Rock concerts ) use larger drivers than lines for smaller areas.
                        The "throw" is greater and SPL is higher. One example is a Versarray which uses a 12" w (2) horn loaded ribbons per array segment.
                        However larger segments have different coverage limitations and these limits are frequency dependent.
                        http://www.qscaudio.com/support/educ...hp?b=part1&p=2
                        "Not a Speaker Designer - Not even on the Internet"
                        “Pride is your greatest enemy, humility is your greatest friend.”
                        "If the freedom of speech is taken away, then dumb and silent we may be led, like sheep to the slaughter."

                        Comment


                        • #13
                          Re: Buyout Vifas for line array?

                          Originally posted by Taterworks View Post
                          The 6" drivers would not be a good solution unless separate smaller HF drivers are used. The 6" drivers by themselves will have center-to-center spacing that is too great to function as a line array in the upper midrange and treble.
                          Of course you would need a HF driver, but I think you would need that with the 3" drivers as well. As pointed out by someone else, the "combing" will come in fairly low.

                          Originally posted by Taterworks View Post
                          I'm not sure why people are naysaying the 3" drivers, when that seems to be the preferred solution among pro audio manufacturers who are actually manufacturing line arrays. To fill in the midbass range, either run stereo subwoofers with a high crossover point (200 Hz or so) or provide midbass modules with something like four beefy 6" woofers, like these: Goldwood heavy-duty 6"

                          In a midbass module, a couple of these would be an even better solution.
                          I don't have a problem with 3" drivers, I'm just not sure this is the best choice, or perhaps even a good choice of a 3 incher, for the reasons stated above.

                          Those series II woofers might work in this situation, were we already have very low efficiency drivers, but that 90db SPL is going to limit the real pro duty application.

                          There is a reason line arrays are not a commonly used system short of large venues.

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                          • #14
                            Re: Buyout Vifas for line array?

                            There is a reason line arrays are not a commonly used system short of large venues.
                            There are dozens of line array manufacturers and most of them reference the same near/field far field graphs that Ureda details in his AES line array papers.
                            It shows how line arrays are intended to trade wide dispersion for controlled directivity over distance.
                            Historically Unshaded arrays where originally used for speech reinforcement only at large distance. Human speech does not require extended HF, so the HF limit placed by large drivers was not a concern, until music reproduction with HF content is desired.
                            "Not a Speaker Designer - Not even on the Internet"
                            “Pride is your greatest enemy, humility is your greatest friend.”
                            "If the freedom of speech is taken away, then dumb and silent we may be led, like sheep to the slaughter."

                            Comment


                            • #15
                              Re: Buyout Vifas for line array?

                              For a speech-range line array (and limited music), the 3" drivers would have plenty of top end. They can probably even be run without a contouring filter (though they will still need a HPF and maybe a pair of small subs). In pro sound, if your design can reach up to 16-18kHz, you can call it a day, because propagation losses really kill extended HF energy in the far field (we don't notice that problem with our hi-fi setups because most hi-fi listening is done in the mid to near field, and most dynamic live sound mics also begin to roll off in the highs.) If you're listening from a distance that is further away than the room's critical distance, the HF rolloff becomes more severe.

                              I think we may be thinking about two completely different product categories. The multi-box line arrays used in pro audio have a lot of non-ideal behavior that goes on with them, to the extent that the decay rate is closer to 4 or 5 dB per doubling of distance than the claimed 6 dB, and their throw characteristics are really related more to the pattern control that's going on, and coming into the pattern of more boxes as you move further away from the array. I'm thinking of the compact line-array columns (Bose MA12, Community Entasys, and others) that use smaller drivers spaced closer together in a single chassis. To achieve line array behavior, your sources must have a maximum spacing of 1/4th the wavelength of the highest frequency they will reproduce.
                              Best Regards,

                              Rory Buszka

                              Taterworks Audio

                              "The work of the individual still remains the spark which moves mankind ahead, even more than teamwork." - Igor I. Sikorsky

                              If it works, but you don't know why it works, then you haven't done any engineering.

                              Comment

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