Announcement

Collapse
No announcement yet.

Towers of Awesomeness Finally Completed

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

  • FredT
    started a topic Towers of Awesomeness Finally Completed

    Towers of Awesomeness Finally Completed

    The Towers of Awesomeness are finally up and playing. Each 7' 11" dipole array incorporated twelve 7" Dayton Esoteric midwoofers and nine BG Neo8 PDR tweeters. The subwoofer is a 12" Dayton Ultimax with the Dayton 500W plate amp. They are controlled by a DEQX digital equalizer and crossover. The crossover is a 48dB/octave at 1,200 hz. For perspective, the ceiling of the alcove behind them is 8'.

  • charlielaub
    replied
    Originally posted by jhollander View Post
    That's the baffle response that needs to be added to the woofer's near field
    Correct (if that was posted as a question).

    Because the woofers are essentially unloaded and operating "free air", and Fs = 33 Hz and Qts = 0.4, there will some droop in the response below 150Hz from the woofer itself. In this case it's really not bad, With F3 = 70Hz and the rolloff only increasing slowly below. Since Fred is crossing over to a sub (I assume at 100Hz or higher) the rolloff doesn't really make much difference in this case.

    I created this response on axis. As you move off axis things will get worse, but the long line (approximately floor to ceiling) and its reflections off of those surfaces will keep things relatively OK. The difficult thing about modeling this kind of system is that you want to include these "line lengthening" reflections, but I do not know of a modeling program that will do that.

    Leave a comment:


  • jhollander
    replied
    That's the baffle response that needs to be added to the woofer's near field

    Leave a comment:


  • charlielaub
    replied
    Fred,

    I did the sim in The Edge for you, attached. This is for the woofers in your speaker at 3m, on axis, free-field. It does not take into account room reflections, and these might be captured in a measurement. Can you post a far-field measurement for the woofers without crossover? I would be very interested in seeing how different the free-field sim and the in-room measurement are for the open baffle line.

    Thanks,

    Charlie


    Click image for larger version

Name:	Tower of Awesomeness woofer sim at 3m on axis.PNG
Views:	1
Size:	257.6 KB
ID:	1417690

    Leave a comment:


  • FredT
    replied
    Originally posted by chad1376 View Post
    OMG - those are sexy! I've built several arrays, but have been limited to cheap buy-out drivers . I can only imagine what these sound like with quality components, after you get them dialed in. Limitless headroom..Hell Yah! You'll go deaf before the drivers are even close to their limits ;)

    One thing I've found. The sound of an array doesn't really "gell" until you get a little distance between you and the speakers. Hopefully those are in a pretty big room.
    The room is 22'W, 38'L, with a 12' ceiling. The ideal seating distance from a line array should be no less than the height of the array or you'll hear the effects of comb filtering. The speakers are about 5' out from the wall behind them, and my listening chair (sofa) is about 12' from the speakers.

    Leave a comment:


  • Unbiasedsound
    replied
    Wow nice work.....only down fall is those speakers will require tall ceilings which wont work in my home. lol

    Leave a comment:


  • charlielaub
    replied
    Originally posted by FredT View Post
    It's very hard to model a line array because of the way an array of woofers behaves
    Modeling a line array is actually quite easy using The Edge set to "open baffle" mode:
    http://www.tolvan.com/index.php?page=/edge/edge.php

    The Edge is a diffraction simulator that can model multiple identical drivers on a closed or open planar baffle of any shape. Drivers can be round or rectangular, so you could model both the line of Esoteric woofers, and/or the line of B&G Neo8's, just not simultaneously. You will at least get a good estimate of the low frequency open baffle response that you can expect from your line, and that is difficult to measure directly. That will help you design the EQ to compensate down to where your sub(s) take over.

    HINT: when you model a driver in The Edge, represent the driver by a shape that represents the radiating area of the driver only. Do not include the frame of the driver. E.G. for a "woofer" that would be the cone and 1/3rd of the surround on either side of it.

    Leave a comment:


  • chad1376
    replied
    OMG - those are sexy! I've built several arrays, but have been limited to cheap buy-out drivers . I can only imagine what these sound like with quality components, after you get them dialed in. Limitless headroom..Hell Yah! You'll go deaf before the drivers are even close to their limits ;)

    One thing I've found. The sound of an array doesn't really "gell" until you get a little distance between you and the speakers. Hopefully those are in a pretty big room.

    Leave a comment:


  • Turtle
    replied
    Those look really nice. They're huge but I imagine it sounds amazing.

    Leave a comment:


  • FredT
    replied
    Originally posted by dynamo View Post
    Wow, they look very nice and your driver quality (and cost) is not insignificant!
    24 Esoteric woofers and 18 BG tweeters do add up to a few $$$. Few speaker manufacturers have been able to successfully market a line array design because of the cost of the parts. If the parts cost $4K the speakers would have to sell for at least $20K. A few small direct sale companies have offered completed line arrays for less than $20K. http://www.selahaudio.com/torre

    Leave a comment:


  • FredT
    replied
    Originally posted by charlielaub View Post
    The only filtering that you mentioned is a 48dB/oct 1.2kHz highpass and lowpass. Are you using any other filtering or EQ as part of the crossover system?

    Have you performed any measurements of, or done any modeling of, the frequency response from the system?
    Yes, those BG Neo8 tweeters have a large peak at about 13khz that must be filtered out. Passive crossovers use a notch filter, I'm using the equalizer in the DEQX. It's very hard to model a line array because of the way an array of woofers behaves - it's much like there's a 6dB/octave filter low pass filter, even with no crossover. I use the Omni mic system to measure, then I make adjustments to the equalizer and measure again until the frequency response looks reasonably smooth. After this I make small adjustments by ear. The DEQX is capable of making all these adjustments automatically with the typical point source speakers but not with a line array. For those who might not be familiar with this technology, here's some info: https://www.deqx.com/technical/
    Last edited by FredT; 07-23-2019, 05:51 AM.

    Leave a comment:


  • dynamo
    replied
    Wow, they look very nice and your driver quality (and cost) is not insignificant!

    Leave a comment:


  • wavefunction
    replied
    I hope they sound as awesome as they look!

    Leave a comment:


  • charlielaub
    replied
    The only filtering that you mentioned is a 48dB/oct 1.2kHz highpass and lowpass. Are you using any other filtering or EQ as part of the crossover system?

    Have you performed any measurements of, or done any modeling of, the frequency response from the system?

    Leave a comment:


  • jhollander
    replied
    Those are cool. They would be a good entry for MWAF, but that would be quite a road trip.

    Leave a comment:

Working...
X