ProSoundWeb Community

Please login or register.

Login with username, password and session length
Advanced search  

Pages: [1] 2 3 ... 7   Go Down

Author Topic: Question about column/stick speaker design  (Read 14884 times)

George Reiswig

  • Newbie
  • *
  • Offline Offline
  • Posts: 28
Question about column/stick speaker design
« on: September 07, 2016, 11:13:57 pm »

So I recently sat in with a band that was using the newer, largest Bose stick system, with all the sticks behind the band.  I was at least a little impressed with them, especially the lack of feedback and lack of need for monitors.

So I started looking for similar speakers that didn't cost as much, and tried out a Turbosound ip2000 "Inspire."  It sounds okay, but I noticed that the spectral balance changes with distance.  I expected that a little bit, because it basically has one tweeter at the very top of the stick, then 17 2" drivers below that.  But what surprised me was that it sounds to me like the 2" drivers are actually being run differently: the ones near the bottom of the stick seem to have a lower HPF on them, the ones above that cut off higher. 

So my question is whether that is bad design, or intentional?  Is it better to...
- have 17 drivers all trying to run as full-range as they can so the spectral pattern is consistent no matter how close you are, or

- have fewer drivers trying to cover the high frequencies because of the shorter wavelength at those frequencies?

Logged

Scott Holtzman

  • Hero Member
  • *****
  • Offline Offline
  • Posts: 5590
  • Ghost AV - Avon Lake, OH
    • Ghost Audio Visual Systems, LLC
Re: Question about column/stick speaker design
« Reply #1 on: September 08, 2016, 03:37:44 am »

So I recently sat in with a band that was using the newer, largest Bose stick system, with all the sticks behind the band.  I was at least a little impressed with them, especially the lack of feedback and lack of need for monitors.

So I started looking for similar speakers that didn't cost as much, and tried out a Turbosound ip2000 "Inspire."  It sounds okay, but I noticed that the spectral balance changes with distance.  I expected that a little bit, because it basically has one tweeter at the very top of the stick, then 17 2" drivers below that.  But what surprised me was that it sounds to me like the 2" drivers are actually being run differently: the ones near the bottom of the stick seem to have a lower HPF on them, the ones above that cut off higher. 

So my question is whether that is bad design, or intentional?  Is it better to...
- have 17 drivers all trying to run as full-range as they can so the spectral pattern is consistent no matter how close you are, or

- have fewer drivers trying to cover the high frequencies because of the shorter wavelength at those frequencies?



I am sure you will get a better answer but it has to do with the spacing.  The drivers have to be a 1/4 wavelength I believe to couple.  At HF a 2" driver is too far apart and will create comb filtering due to the mismatch.

I have seen hi-fi speakers that have a parallel HF array, usually ribbons for the dispersion characteristics next to the "mid" frequency line array.   This works well sitting in the close field but probably not optimum for sound reinforcement hence the classic dull sound of all the column arrays.

In non technical terms even as a kid I always thought the Bose arrays, including the much vaunted 901's sounded like shit.  As a little kid I would argue with my parents friends trying to tell me how good they sounded.  I imagine it was fairly obnoxious, just like the sound of the speakers.
« Last Edit: September 08, 2016, 07:30:01 am by Scott Holtzman »
Logged
Scott AKA "Skyking" Holtzman
River Delta Audio is now:

Ghost Audio Visual Solutions, LLC
Cleveland OH
www.ghostav.rocks

Robert Piascik

  • Hero Member
  • *****
  • Offline Offline
  • Posts: 697
  • Hilliard, OH (near Columbus)
Re: Question about column/stick speaker design
« Reply #2 on: September 08, 2016, 06:26:27 am »


I imagine (I) was fairly obnoxious, just like the sound of the speakers.


At least the speakers had a volume knob they could turn down...

😀😀😀
Logged
Pi Entertainment Services
Midas M32R / MR18
Behringer X32R / XR12
Danley SH50 / SM80 / TH118 / TH115
Fulcrum Acoustic fa22ac
RCF NX 12SMA
Yamaha DSR112
Powersoft X4 / M50Q
Crown iT8k / Xti6k

Ivan Beaver

  • Hero Member
  • *****
  • Offline Offline
  • Posts: 8866
  • Atlanta GA
Re: Question about column/stick speaker design
« Reply #3 on: September 08, 2016, 07:46:52 am »



- have fewer drivers trying to cover the high frequencies because of the shorter wavelength at those frequencies?
The best and most pure approach is to have a single driver cover the intended bandwidth.

Beyond that, a cabinet that produces a single source (orientation) of sound is better than one that has sound coming from physically different places-resulting in different signal arrivals at your ear.

Once you start to have different signal arrivals, all sorts of other things start to come into play in what you hear and how it behaves.

Everything is a compromise, and most often the compromise is what people "think" they want-without understanding the real factors involved.

The biggest difference is what does it sound like at different places?  As you move around the coverage pattern-is the sound the same?

A fun "trick" to play with "column speakers" is to turn them on their sides and get up around ear height-give or take a foot or so.

No put in pink noise and walk from one end to the other.

Does it sound the same?  If not- you need to ask yourself "Is my audience hearing different things depending on where they are seated?"
Logged
A complex question is easily answered by a simple-easy to understand WRONG answer!

Ivan Beaver
Danley Sound Labs

PHYSICS- NOT FADS!

Scott Helmke

  • Hero Member
  • *****
  • Offline Offline
  • Posts: 1400
Re: Question about column/stick speaker design
« Reply #4 on: September 08, 2016, 10:01:43 am »

Those column/line speakers do have some specific uses, though I think (for the price) the "everybody has a Bose stick" solution isn't that great.

More drivers = more bass, which is generally considered good. With some speakers it's common to have say two same-size drivers for both bass and mids, but filter the mids out of one of the speakers. That's because you don't want the mids coming from two different places at the same time, causing comb filtering.  Because the bass has much longer wavelengths you can have multiple drivers without much comb filtering.

I've seen some column designs that do the same thing over the length of the column.
Logged

Brian Jojade

  • Hero Member
  • *****
  • Offline Offline
  • Posts: 1459
    • HappyMac Digital Electronics
Re: Question about column/stick speaker design
« Reply #5 on: September 08, 2016, 11:05:31 am »

The iP2000 is a decent cabinet, although, when you get close to it, it sounds a bit 'weird'  Once you get about 10-15 feet away, it sounds great.

It's a decent system for smaller rooms, and due to the speaker design, you can get great GBF when right next to the speaker.  Once you get away from the speaker, the GBF is similar to traditional cabinets.
Logged
Brian Jojade

Robert Piascik

  • Hero Member
  • *****
  • Offline Offline
  • Posts: 697
  • Hilliard, OH (near Columbus)
Re: Question about column/stick speaker design
« Reply #6 on: September 08, 2016, 11:21:00 am »

I'm not a fan of the column stick speakers but a friend (solo singer/guitarist) has the Turbosound unit and I went to see him play and I was surprised that it sounded fine. Then I came onstage and played and sang a couple of tunes and felt like I couldn't hear myself standing right in front of it! It was the weirdest experience. How can that be?
Logged
Pi Entertainment Services
Midas M32R / MR18
Behringer X32R / XR12
Danley SH50 / SM80 / TH118 / TH115
Fulcrum Acoustic fa22ac
RCF NX 12SMA
Yamaha DSR112
Powersoft X4 / M50Q
Crown iT8k / Xti6k

George Reiswig

  • Newbie
  • *
  • Offline Offline
  • Posts: 28
Re: Question about column/stick speaker design
« Reply #7 on: September 08, 2016, 12:03:07 pm »

The best and most pure approach is to have a single driver cover the intended bandwidth.

Beyond that, a cabinet that produces a single source (orientation) of sound is better than one that has sound coming from physically different places-resulting in different signal arrivals at your ear.

I am a fan of coincident drivers that are time-aligned.  But I also found that Bose experience pretty compelling: it didn't sound "too dull" to me, and I well remember the "No highs, no lows, must be Bose" experience I've had previously.  Mind you, I've spent too much time on loud stages and don't hear up to 20kHz anymore.  But more compellingly, the lack of dropoff of volume as you moved away from the speakers was really attractive.  I like the idea of being able to get a relatively uniform volume level front-to-back for small venues. 

My very limited understanding of the way the coupling works in these units is that for lower frequencies the dispersion pattern is not hemispherical, but semi-cylindrical, and the pattern itself lends to this lack of volume drop?  At 10kHz, wavelength is around 3.4cm, right?  So the drivers would have to be 1.7cm in diameter to achieve proper coupling at that frequency, or would have to use waveguides or a ribbon or something. 

But I still go back to that experience with the Bose systems: it sounded pretty respectable. 

Does anyone know whether Bose gets all 24 of their drivers reproducing the same frequency range, or whether they do something like what it sounds like Turbosound is doing that I described earlier?
Logged

George Reiswig

  • Newbie
  • *
  • Offline Offline
  • Posts: 28
Re: Question about column/stick speaker design
« Reply #8 on: September 08, 2016, 12:14:22 pm »

The iP2000 is a decent cabinet, although, when you get close to it, it sounds a bit 'weird'  Once you get about 10-15 feet away, it sounds great.

It's a decent system for smaller rooms, and due to the speaker design, you can get great GBF when right next to the speaker.  Once you get away from the speaker, the GBF is similar to traditional cabinets.

I'm not as impressed with it as I remember being with the Bose setup*, and now I'm very curious as to why that is the case.  It sounds okay, but not great.  I have an opportunity to try it doing SR for my wife's voice student recital this weekend, where I had hoped it would serve as mains and monitor for all vocals and keyboards.  I think I'm going to end up taking a couple of Yamaha DXR10's just in case.

*hardly a fair A/B comparison, memory...
« Last Edit: September 08, 2016, 01:06:07 pm by George Reiswig »
Logged

Tim McCulloch

  • SR Forums
  • Hero Member
  • *
  • Offline Offline
  • Posts: 20454
  • Wichita, Kansas USA
Re: Question about column/stick speaker design
« Reply #9 on: September 08, 2016, 02:50:47 pm »

George, look at the POLAR patterns for whatever "stick" PA you're considering.  You'll find the LF is almost 360, the HF (above 4kHz) to be much, much narrower.  It tapers as the frequency increases.  Listen very carefully to the off-axis tonality...
« Last Edit: September 08, 2016, 02:54:13 pm by Tim McCulloch »
Logged
"Practicing an art, no matter how well or badly, is a way to make your soul grow, for heaven's sake. Sing in the shower. Dance to the radio. Tell stories. Write a poem to a friend, even a lousy poem. Do it as well as you possible can. You will get an enormous reward. You will have created something."  - Kurt Vonnegut

ProSoundWeb Community

Re: Question about column/stick speaker design
« Reply #9 on: September 08, 2016, 02:50:47 pm »


Pages: [1] 2 3 ... 7   Go Up
 



Page created in 0.15 seconds with 22 queries.