Print

Please login or register.
1 Hour 1 Day 1 Week 1 Month Forever
Login with username, password and session length

[John Chiara]

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...

The older Bose sticks had sliding crossover points as part of some 'dynamic' processing concept. They were never loud enough...and changed tone drastically when pushed hard. For what they cost I could never see the point. A couple DXR 10's and a small sub would kick their butt...IMO. What is the rated output of the new models?

[George Reiswig]

The older Bose sticks had sliding crossover points as part of some 'dynamic' processing concept. They were never loud enough...and changed tone drastically when pushed hard. For what they cost I could never see the point. A couple DXR 10's and a small sub would kick their butt...IMO. What is the rated output of the new models?

For the cost, I agree.  My hope with the Turbosound was that I could get similar performance (not huge SPL's) at less than a third the cost.  This weekend will tell a lot. 

I guess I'd hope for the lack of volume extremes front to rear, decent (but nonlethal) SPL on tap, and good, even frequency response down to the subwoofer point.  Starting to sound like this is a physical impossibility with the current state of drivers, unless you go much bigger...i.e. non-portable for the working band.

[John Chiara]

For the cost, I agree.  My hope with the Turbosound was that I could get similar performance (not huge SPL's) at less than a third the cost.  This weekend will tell a lot. 

I guess I'd hope for the lack of volume extremes front to rear, decent (but nonlethal) SPL on tap, and good, even frequency response down to the subwoofer point.  Starting to sound like this is a physical impossibility with the current state of drivers, unless you go much bigger...i.e. non-portable for the working band.

RCF and other companies are offering similar products.

[George Reiswig]

RCF and other companies are offering similar products.

I've seen some of those.  I may have a misperceptions, but I look at the relatively low number of drivers on the JBL and RCF units and think that they must not have as much of that effect of "volume doesn't drop with distance" as units like the Bose.  Is that just faulty understanding?

[Don T. Williams]

Actually the Turbosound iP2000's do have stepped (different) cross-over frequencies for different parts of the columns if I understand correctly.  I suspect it is an attempt to "improve" the vertical dispersion. 

I have a set of K-Array Red Line KR-200's with 32 - 2.125" drivers in each 2 meter tall "stick" that is powered by a 18" sub box containing two 1K amp channels.  The claimed vertical dispersion is 7 degrees (110 degrees horizontally).  The newer KR 202 has selectable (7 and 35 degree) dispersion.  In venues like a large gym or arena with seating only on the floor, this is my go to system and works better than anything else I have used in those situations. 

I've covered over 1000 people with a pair for moderately loud music and loud voice in normally difficult reverberant spaces.  Because of the narrow vertical dispersion, they don't seem to "excite" the room's reverb.  I add one or two additional single 18" subs per side for " bass heavy" music.  The KR 200's (and KR 202's) are rated at 130 dB continuous (136 dB peak).  These are NOT the Bose Lt1,  those are a Pinto . . . these a Ferrari!  That is reflected in its price also.  It will not work with raked seating - too flat vertically.

[Ivan Beaver]

I've seen some of those.  I may have a misperceptions, but I look at the relatively low number of drivers on the JBL and RCF units and think that they must not have as much of that effect of "volume doesn't drop with distance" as units like the Bose.  Is that just faulty understanding?

The number of drivers has little to nothing to do with the "SPL loss over distance"

In a line array/source, that depends on the physical length of the array (size).

Of course the spacing of the drivers depends on the wavelength of interest.

The ACTUAL SPL loss over distance depends on the freq AND the length of the array.

Short arrays only exhibit the 3dB/doubling loss in the top octave or so.  It takes long lines to control down lower.

It is a common misconception that a "line array" covers an audience better than a "point source" speaker.

In an open field-yes (assuming the line is long enough) and on axis.

But if you were to put a point source in the same physical position (top of the line array)  you will often find that the point source will cover better.

Yes this varies with the particular speakers.

But when people like to try to do the comparisom, they are willing to use the specs of the line array when hung above peoples heads and the point source down at head height.

The very thing that allows for the smoother coverage is the off axis response.

In many cases the SAME SPL can be achieve at the front row as the back row.

So the "loss over distance" is not at all that some people would like to believe it is with a point source.

You MUST use the same conditions for both systems if you actually want to do an accurate comparison.

[Scott Holtzman]

The number of drivers has little to nothing to do with the "SPL loss over distance"

In a line array/source, that depends on the physical length of the array (size).

Of course the spacing of the drivers depends on the wavelength of interest.

The ACTUAL SPL loss over distance depends on the freq AND the length of the array.

Short arrays only exhibit the 3dB/doubling loss in the top octave or so.  It takes long lines to control down lower.

It is a common misconception that a "line array" covers an audience better than a "point source" speaker.

In an open field-yes (assuming the line is long enough) and on axis.

But if you were to put a point source in the same physical position (top of the line array)  you will often find that the point source will cover better.

Yes this varies with the particular speakers.

But when people like to try to do the comparisom, they are willing to use the specs of the line array when hung above peoples heads and the point source down at head height.

The very thing that allows for the smoother coverage is the off axis response.

In many cases the SAME SPL can be achieve at the front row as the back row.

So the "loss over distance" is not at all that some people would like to believe it is with a point source.

You MUST use the same conditions for both systems if you actually want to do an accurate comparison.

I won a box full of really nice 4" drivers on eBay for just about the shipping.  I have over 100lbs of them.   I think enough to make two 6' lines.  Was thinking about cutting PVC pipe and putting in some sort of rail and loading the drivers in.  Just an experiment.

[George Reiswig]

The number of drivers has little to nothing to do with the "SPL loss over distance"

In a line array/source, that depends on the physical length of the array (size).

(SNIP of much useful info)

I'm grateful t everyone here for the help, but Ivan, I am particularly grateful to you for your detailed, informative replies here.  I have learned a lot.  And by the way, I heard a church trying out a trio of three smallish (220lbs?) full range Danley cabs in an LCR configuration.  I was seriously, seriously impressed. 

[Mike Pyle]

Columns r us.

[Stephen Kirby]

I won a box full of really nice 4" drivers on eBay for just about the shipping.  I have over 100lbs of them.   I think enough to make two 6' lines.  Was thinking about cutting PVC pipe and putting in some sort of rail and loading the drivers in.  Just an experiment.

Have you ever heard of "pipe resonance"?      Basically the same thing the Blue Man Group uses whacking the ends of PVC pipes with paddles.  Any high aspect ratio enclosure will have an issue unless it is internally baffled to break up the waves bouncing end to end.

[ProSoundWeb Community]