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Thread: 3 RAAL Towers or 3 RAAL Horizon for front LCR

  1. #21
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    Default Re: 3 RAAL Towers or 3 RAAL Horizon for front LCR

    Quote Originally Posted by Roen View Post
    Have you done any lobing tests on a vertically oriented Horizon? Would it show improvements vs. horizontal?
    Are you sure you have a firm understanding of what you are discussing? There is really no such thing as a "lobing test". Lobing shows itself on the most basic of off-axis frequency response measurements, of which we publicly post for all of our speakers. I know you don't fully understand this, but asking if I evaluate off-axis response measurements of our speakers is like asking a Physics PHD if he understands the Mass-Energy Equivalence Formula or asking a mechanic if he knows how to change the oil in a car It is, perhaps, the most basic starting point for speaker design (at least for somewhat competent engineers)

    May I ask why you are so concerned with this? As I stated, horizontal off-axis lobing is not an issue with the Horizon.

    Please see the polar response here: http://www.ascendacoustics.com/image...rizonpolar.gif


    Did you read Audioholics conclusion in that same article? As quoted in the article:

    "Acoustical interference caused by multiple drivers playing the same bandwidth is a non-issue if the radiating driver's cutoff frequency is low enough so that the distance between adjacent drivers is small relative to the wavelengths they are producing in equal or near equal proportions. (This is known in filter-speak as the "transition band" or "crossover band"). As the order of the crossover is increased (6 dB to 12 dB to 18 dB to 24 dB or beyond), the amount of phase shift within the crossover band increases, so the likelihood of the two speakers being out of phase at any given angle off-axis increases, while the frequency range over which this is an issue decreases. This is why it can be acceptable to horizontally place multiple woofers and midranges (if the center to center distance between them is closer than the highest wavelength of operation) but, typically NOT tweeters."
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    David Fabrikant
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  2. #22
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    Default Re: 3 RAAL Towers or 3 RAAL Horizon for front LCR

    Quote Originally Posted by davef View Post
    Are you sure you have a firm understanding of what you are discussing? There is really no such thing as a "lobing test". Lobing shows itself on the most basic of off-axis frequency response measurements, of which we publicly post for all of our speakers. I know you don't fully understand this, but asking if I evaluate off-axis response measurements of our speakers is like asking a Physics PHD if he understands the Mass-Energy Equivalence Formula or asking a mechanic if he knows how to change the oil in a car It is, perhaps, the most basic starting point for speaker design (at least for somewhat competent engineers)

    May I ask why you are so concerned with this? As I stated, horizontal off-axis lobing is not an issue with the Horizon.

    Please see the polar response here: http://www.ascendacoustics.com/image...rizonpolar.gif


    Did you read Audioholics conclusion in that same article? As quoted in the article:

    "Acoustical interference caused by multiple drivers playing the same bandwidth is a non-issue if the radiating driver's cutoff frequency is low enough so that the distance between adjacent drivers is small relative to the wavelengths they are producing in equal or near equal proportions. (This is known in filter-speak as the "transition band" or "crossover band"). As the order of the crossover is increased (6 dB to 12 dB to 18 dB to 24 dB or beyond), the amount of phase shift within the crossover band increases, so the likelihood of the two speakers being out of phase at any given angle off-axis increases, while the frequency range over which this is an issue decreases. This is why it can be acceptable to horizontally place multiple woofers and midranges (if the center to center distance between them is closer than the highest wavelength of operation) but, typically NOT tweeters."
    I do not, hence why I am asking.

    Just trying to see if the same pattern of vertical orientation being better than horizontal orientation as shown in the audioholics article holds for the horizon as well.
    Last edited by Roen; 09-06-2017 at 07:52 PM.

  3. #23
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    Default Re: 3 RAAL Towers or 3 RAAL Horizon for front LCR

    Quote Originally Posted by Roen View Post
    I do not, hence why I am asking.

    Just trying to see if the same pattern of vertical orientation being better than horizontal orientation as shown in the audioholics article holds for the horizon as well.
    If you look at the measurements posted on our website here: http://www.ascendacoustics.com/pages...n/hormeas.html

    specifically, the horizontal and vertical off-axis graphs, you will see that the horizontal placement is technically "better" than vertical placement.
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    David Fabrikant
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  4. #24
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    Default Re: 3 RAAL Towers or 3 RAAL Horizon for front LCR

    Quote Originally Posted by davef View Post
    If you look at the measurements posted on our website here: http://www.ascendacoustics.com/pages...n/hormeas.html

    specifically, the horizontal and vertical off-axis graphs, you will see that the horizontal placement is technically "better" than vertical placement.
    Without belaboring this point too much longer, would the off-axis response change at all if the tweeter is rotated 90 degrees?

  5. #25
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    Default Re: 3 RAAL Towers or 3 RAAL Horizon for front LCR

    Quote Originally Posted by Roen View Post
    Without belaboring this point too much longer, would the off-axis response change at all if the tweeter is rotated 90 degrees?
    Ribbon tweeters must be used in a vertical (upright) orientation. If you were to use the Horizon vertically, the ribbon must be rotated 90 degrees.
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    David Fabrikant
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  6. #26
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    Default Re: 3 RAAL Towers or 3 RAAL Horizon for front LCR

    Quote Originally Posted by davef View Post
    Ribbon tweeters must be used in a vertical (upright) orientation. If you were to use the Horizon vertically, the ribbon must be rotated 90 degrees.
    Thanks for that response, but i was inquiring whether, after the tweeter is rotated 90 degrees, and the speaker retested, would the vertical and horizontal on-axis / off-axis graphs look measurably different than what has been posted or would I expect that they look the same, except that vertical dispersion is now horizontal dispersion and vice versa?

  7. #27
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    Default Re: 3 RAAL Towers or 3 RAAL Horizon for front LCR

    Quote Originally Posted by Roen View Post
    Thanks for that response, but i was inquiring whether, after the tweeter is rotated 90 degrees, and the speaker retested, would the vertical and horizontal on-axis / off-axis graphs look measurably different than what has been posted or would I expect that they look the same, except that vertical dispersion is now horizontal dispersion and vice versa?
    From approx. 1800Hz and up the response is mostly influenced by the tweeter. If the tweeter is not in the proper orientation, you are going to see a dramatic high frequency roll-off, the greater the off-axis angle - the greater the rolloff.

    The mid-range response will also not be the same compared to vertical vs. horizontal positioning, regardless of the tweeter orientation.

    Due to the length of bass wavelengths, the bass response would be the same regardless of vertical vs horizontal positioning.

    So to answer your question, if we rotate the tweeter 90 degrees and retake our off-axis measurements, the response would look nothing like what we have posted. What is posted on our website is with the speaker oriented in a horizontal position with the tweeter in the correct orientation. The vertical response posted on our website is with the speaker positioned horizontally. This is the common usage of the speaker.
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    Good Sound To You!

    David Fabrikant
    www.ascendacoustics.com

  8. #28
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    Default Re: 3 RAAL Towers or 3 RAAL Horizon for front LCR

    Quote Originally Posted by davef View Post
    From approx. 1800Hz and up the response is mostly influenced by the tweeter. If the tweeter is not in the proper orientation, you are going to see a dramatic high frequency roll-off, the greater the off-axis angle - the greater the rolloff.

    The mid-range response will also not be the same compared to vertical vs. horizontal positioning, regardless of the tweeter orientation.

    Due to the length of bass wavelengths, the bass response would be the same regardless of vertical vs horizontal positioning.

    So to answer your question, if we rotate the tweeter 90 degrees and retake our off-axis measurements, the response would look nothing like what we have posted. What is posted on our website is with the speaker oriented in a horizontal position with the tweeter in the correct orientation. The vertical response posted on our website is with the speaker positioned horizontally. This is the common usage of the speaker.
    I apologize, I meant to say if the tweeter was rotated 90 degrees and the speaker was set vertically instead of horizontally, will the responses look similar? Interested in the alternate usage of the Horizon, which would be in vertical orientation with a properly oriented tweeter for vertical use.

  9. #29
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    Default Re: 3 RAAL Towers or 3 RAAL Horizon for front LCR

    Quote Originally Posted by Roen View Post
    I apologize, I meant to say if the tweeter was rotated 90 degrees and the speaker was set vertically instead of horizontally, will the responses look similar? Interested in the alternate usage of the Horizon, which would be in vertical orientation with a properly oriented tweeter for vertical use.
    Ahh - now I understand, thanks for the clarification. Yes, in this regard, with the Horizon positioned vertically and the tweeter properly oriented - measurements (both vertical and horizontal) would be very similar. On-Axis would be identical -- off-axis, starting at about +/- 30 degrees would start to show some minor differences in the range of 1kHz - 4kHz, but again, only minor and I strongly doubt you would ever be that far off-axis while listening.
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    Good Sound To You!

    David Fabrikant
    www.ascendacoustics.com

  10. #30
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    Default Re: 3 RAAL Towers or 3 RAAL Horizon for front LCR

    Quote Originally Posted by davef View Post
    Ahh - now I understand, thanks for the clarification. Yes, in this regard, with the Horizon positioned vertically and the tweeter properly oriented - measurements (both vertical and horizontal) would be very similar. On-Axis would be identical -- off-axis, starting at about +/- 30 degrees would start to show some minor differences in the range of 1kHz - 4kHz, but again, only minor and I strongly doubt you would ever be that far off-axis while listening.
    Thanks!

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