ProSoundWeb Community

Please login or register.

Login with username, password and session length
Advanced search  

Pages: 1 2 [3]   Go Down

Author Topic: Arraying horn loaded subs,options?  (Read 2155 times)

Steve Litscher

  • Full Member
  • ***
  • Offline Offline
  • Posts: 168
    • 608 Sound and Light
Re: Arraying horn loaded subs,options?
« Reply #20 on: August 10, 2017, 11:24:58 am »


It is best to NOT to generalize, but to look at SPECIFIC boxes to get actual answers.



I'm interested in this, as I've experienced instances where "pairs" of tapped horn subs (2 per side) have produced significant nulls at off-axis positions (-10dB from center/FOH position). Most notably when standing between 45-degrees to 90-degrees off axis from the pair of subs on either side of the stage.

How do pairs of deployed TH-118s avoid such nulls? Or, is there delay being used with one of the pair? I usually see them with the horn mouth on the ground, set "side-by-side" (not stacked or with wheels opposite of one another), and coverage seems very uniform.

I have experienced nulls with single 18 tapped horns when paired-up and split 25-feet (stage width), even with delaying the outer pair, so I'm curious how the TH-118s avoid this phenomenon.

Rob Spence

  • Hero Member
  • *****
  • Offline Offline
  • Posts: 2470
  • Boston Metro North/West
    • Lynx Audio Services
Re: Arraying horn loaded subs,options?
« Reply #21 on: August 10, 2017, 12:07:39 pm »


I'm interested in this, as I've experienced instances where "pairs" of tapped horn subs (2 per side) have produced significant nulls at off-axis positions (-10dB from center/FOH position). Most notably when standing between 45-degrees to 90-degrees off axis from the pair of subs on either side of the stage.

How do pairs of deployed TH-118s avoid such nulls? Or, is there delay being used with one of the pair? I usually see them with the horn mouth on the ground, set "side-by-side" (not stacked or with wheels opposite of one another), and coverage seems very uniform.

I have experienced nulls with single 18 tapped horns when paired-up and split 25-feet (stage width), even with delaying the outer pair, so I'm curious how the TH-118s avoid this phenomenon.

You seem to believe that if a sub is a tapped horn design that it is designed well and has been measured to perform well.

Not all speakers that are built and sold are designed well or built well. This goes for any basic design be it horn, tapped horn, reflex, 2 way tops, 3 way tops, horn tops.

There is more to making a well behaved speaker than cutting out some plywood.

You do not identify any of the speakers you have been dissatisfied with. Why?



Sent from my iPad using Tapatalk HD
Logged
rob at lynxaudioservices dot com

Dealer for: AKG, Allen & Heath, Ashley, Astatic, Audix, Blue Microphones, CAD, Chauvet, Community, Countryman, Crown, DBX, Electro-Voice, FBT, Furman, Heil, Horizon, Intellistage, JBL, Lab Gruppen, Mid Atlantic, On Stage Stands, Pelican, Peterson Tuners, Presonus, ProCo, QSC, Radial, RCF, Sennheiser, Shure, SKB, Soundcraft, TC Electronics, Telex, Whirlwind and others

Ivan Beaver

  • Hero Member
  • *****
  • Offline Offline
  • Posts: 8182
  • Atlanta GA
Re: Arraying horn loaded subs,options?
« Reply #22 on: August 10, 2017, 12:27:33 pm »

You seem to believe that if a sub is a tapped horn design that it is designed well and has been measured to perform well.

Not all speakers that are built and sold are designed well or built well. This goes for any basic design be it horn, tapped horn, reflex, 2 way tops, 3 way tops, horn tops.

There is more to making a well behaved speaker than cutting out some plywood.

You do not identify any of the speakers you have been dissatisfied with. Why?



Sent from my iPad using Tapatalk HD
Agreed.  not all "designs" perform the same.

It depends on the particular "design".

BTW, most of the DIY tapped horns are not done properly, and are missing a key element (NO, I will not say what it is-don't ask).

And as a result, they do not perform like a proper design.
Logged
A complex question is easily answered by a simple-easy to understand WRONG answer!

Ivan Beaver
Danley Sound Labs

PHYSICS- NOT FADS!

Eugen Jeličić

  • Full Member
  • ***
  • Offline Offline
  • Posts: 140
Re: Arraying horn loaded subs,options?
« Reply #23 on: August 10, 2017, 08:34:11 pm »

Yes, that is the thing. I don't know how these invader bins have been made, are there building mistakes causing problems. But i didn't think that the way a subwoofer box is designed can do very much difference in 40-50-60hz dispersion. Considering how small the box is compared to the wavelenght.

And how can coverage pattern change when you go from one to two tapped horns? Shouldn't they just "couple" at low frequencies? Start working like one box?
Having exactly the same dispersion as one box, just with more power?

I mean there is no room for interference with two boxes playing 50hz staying side by side. Only if the frequency goes up?
Logged

Art Welter

  • Hero Member
  • *****
  • Offline Offline
  • Posts: 1157
Re: Arraying horn loaded subs,options?
« Reply #24 on: August 28, 2017, 08:52:41 pm »


ART:

That's why the lowcut filter is applied right? To stop the driver from exceeding xmax and doing damage to itself.
Just like with reflex boxes. Once you pass the port resonance, the box stops loading the driver well. Therefore the driver starts moving too much and flapping, potentialy damaging itself. So you apply a LC filter?

Or my logics failed me? Can you explain what you wrote up there a bit better?
You claim that driver moves the most almost an octave above the LC.
We set the LC for the invaders at 35hz.
Eugen,
I wrote:
 "Obviously, with high power, a steep HP filter at Fc must be used unless you like the sound of flapping cones ;^)."

A HP (High Pass) filter is the usual name for a Low Cut filter (LC is generally not used, as it can be confused for an LC coil/capacitor network) but as you can see in the FLH simulation, excursion is greatest (other than below FC) a bit under an octave above Fc,  which happened to be about the upper cutoff frequency (Low Pass filter) you chose on the gig in question.

Since the "Invader" has a higher Fc than the examples shown, the upper excursion peak would also be higher than the examples. The 35 Hz HP you used does nothing to limit the upper excursion peak, which becomes the "flap" frequency.

This is true for all FLH, TH, and BR alignments, the only alignment that excursion increases directly as frequency is lowered is a sealed box.

Art
Logged
Pages: 1 2 [3]   Go Up
 


Page created in 0.185 seconds with 17 queries.