Coaxial Wedge Collaboration

Re: Coaxial Wedge Collaboration

Another aspect I'd like to begin discussing is the box geometry.I always seam to run into situations where the stage is short in depth or the band is forced to play out of a corner. When that happens it's difficult to get the wedge firing right at the talent.

Another problem I run into is the vice effect on larger wide open stages. Sometimes depending on the wedges I use it seams as though the singers are stuck in a vise. Any great movement left or right and they loose the ineligibility of the wedge. I attribute this to the HF section or the crossover point.Often I would need some side fills for the very mobile front guys/gals.

Note: We use several different types of wedges and some are worse than the others.

Your thoughts on whats a better choice for HF dispersion,besides in-ears! LOL

Traditional horns,HF waveguide,etc?

Multiple angles on the build and if so what would be the best choices?

Geometry where pack space is involved.

Weight.
 
Re: Coaxial Wedge Collaboration

The B&C I suggested has an 80deg conical horn. This would be a good balance I think. I find 60deg wedges have the issues you describe for ''mobile'' talent, while overly wide patterns can sometimes spill into other performer's areas which can make life more difficult if you have a lot of separate mixes onstage.

I'd actually suggest not having multiple angles on the build. I'd rather have a design more along the lines of a microwedge-esque sort of thing (though without curves etc), and if you really need a steeper angle, simply prop it slightly with either a basic shim specifically for that purpose, or perhaps even via an integrated fold out locking leg mechanism on the bottom of the wedge.

It would be great if we could come up with something that would be small enough to use as a front fill in a pinch too.

Of course this is just my perspective, others are welcome.
 
Re: Coaxial Wedge Collaboration

agreed, the 'walking out of the monitor beam' is an issue for a wedge. It is usually caused by a 40x90 horn on it's side, and crossing at 2-4k. That's crossed too high, and too narrow horizontal beamwidth.

I personally think crossing as low as possible, and using a wide dispersion HF is mandatory. (which is why I thought about the ribbon)

1.2khz and 75 degree conical would be my targets to avoid the 'beam'.
 
Re: Coaxial Wedge Collaboration

James Bell wrote on Fri said:
agreed, the 'walking out of the monitor beam' is an issue for a wedge. It is usually caused by a 40x90 horn on it's side, and crossing at 2-4k. That's crossed too high, and too narrow horizontal beamwidth.



I personally think crossing as low as possible, and using a wide dispersion HF is mandatory. (which is why I thought about the ribbon)



1.2khz and 75 degree conical would be my targets to avoid the 'beam.'
Click to expand...



Your ribbon still interests me. Though the B&C I mention is also very close to your suggested parameters (80 deg conical and 1.2K suggested crossover)



PS - Sorry if I seem overly pushy about this driver.
 
Re: Coaxial Wedge Collaboration

Jeff Babcock wrote on Fri said:
James Bell wrote on Fri said:
agreed, the 'walking out of the monitor beam' is an issue for a wedge. It is usually caused by a 40x90 horn on it's side, and crossing at 2-4k. That's crossed too high, and too narrow horizontal beamwidth.

I personally think crossing as low as possible, and using a wide dispersion HF is mandatory. (which is why I thought about the ribbon)

1.2khz and 75 degree conical would be my targets to avoid the 'beam.'
Click to expand...
Your ribbon still interests me. Though the B&C I mention is also very close to your suggested parameters (80 deg conical and 1.2K suggested crossover)

PS - Sorry if I seem overly pushy about this driver.
Click to expand...

not pushy at all... in fact this is exactly what this forum is about -- exchange of ideas in an agreeable manner. At some point we may disagree (which is a good thing) but we can be civil and agreeable about it.

Is there documentation on the expansion rate/flare of the conical on the b&c ? (sorry, at work and haven't looked up the b&c specs)
also, what 1'' comp driver you have in mind that can cross at 1.2K ? most 2'' can, but most 1'' are 2k or higher.

we should also spend a few brain cycles on the target response, or at least the response compromises we are willing to accept. I personally don't have an issue with a monitor with a slight dip at 800hz, a ''slight'' rolloff from 100hz-down to 80hz, and also don't have an issue with a monitor with a slight rolloff starting at about 10k on up. It HAS to do 80hz though... anything less than that is a non starter in my world. (church's) No -- 80hz is not necessary in the 120db stage screamer volume world, but in the 85db stage world of church, if the monitor can't do 80hz, it's ''tinny''
 
Re: Coaxial Wedge Collaboration

James Bell wrote on Fri said:
Is there documentation on the expansion rate/flare of the conical on the b&c ? (sorry, at work and haven't looked up the b&c specs)

also, what 1'' comp driver you have in mind that can cross at 1.2K ? most 2'' can, but most 1'' are 2k or higher.
Click to expand...



Here are the B&C specs. It is NOT a 1'' comp driver (however, note that there are a few 1'' drivers capable of 1.2K crossover, like BMS4552ND). BTW I agree re usable to 80Hz, users can always raise HPF in processing if desired. This is a pretty capable coax driver. It checks a lot of boxes for me, including being very lightweight.





B&C 12CXN76 Specifications



320 mm (12 in) Nominal Diameter

8 ohm Nominal Impedance

6.5 Ohm (LF) 8 Ohm (HF) Minimum Impedance

45 - 18000 Hz Frequency Range

80° Dispersion Angle

1.2 kHz Recom Crossover







LF Unit

99 dB Sensitivity (1W/1m)

700 WContinuous Power Handling

350 WNominal Power Handling (AES)

76 mm (3 in) Voice Coil Diameter





HF Unit

105 dB Sensitivity (1W/1m)

160 W Continuous Power Handling

80 W Nominal Power Handling (AES)

75 mm (3 in) Voice Coil Diameter





Parameters

42 Hz Fs

5 ohm Re

0.2 Qes

8 Qms

0.19 Qts

120 dm3 (4.20 ft3) Vas

522 cm2 (80.90 in2)Sd

4.1 %η0

± 4 mm Xmax

± 6 mm Xvar

47 g Mms

17.6 Txm Bl

0.8 mH Le



Mounting info

315 mm (12.4 in) Overall Diameter

298 mm (11.7 in) Bolt Circle Diameter

282 mm (11.1 in) Baffle Cutout Diameter

170 mm (6.7 in) Depth

14 mm (0.55 in) Flange and Gasket Thickness

5 kg (11 lb) Net Weight





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Re: Coaxial Wedge Collaboration

Quote: said:
As of now we haven't determined the box type or configuration.
Click to expand...

I wondered: was it to be a fixed rake, or to include adjustment like a QSC CSM monitor?

I'm not clear as to the desired dispersion pattern?
 
Re: Coaxial Wedge Collaboration

I forgot about those CSM monitors. I do like the concept of the angle adjustment feet on those.



The ''pattern control shutter'' concept of those is also interesting, though I expect that trying to develop something similar would not be a trivial process.
 
Re: Coaxial Wedge Collaboration

Oops sorry Robert, I accidentally edited your post rather than replying, and can't recall the exact wording of your question to get it back.



Sorry about this. Re what you had said (re feet and dispersion inquiry): my reply will be below.



Sorry again for this mistake,

Jeff





 
Re: Coaxial Wedge Collaboration



I agree, adjustable feet would be a nice touch. In simplest form, perhaps even large rubber feet on a bolt setup, where you simply spin the foot to raise or lower it. This would be cheap to implement and with a robust base and bolt it would likely hold up well.



Re the pattern, personally I prefer the idea of a conical horn so that the dispersion remains the same regardless of orientation.
 
Re: Coaxial Wedge Collaboration

I've started running some of the suggested drivers in Eminence Designer.Choosing various box sizes and tunings and the like.One of the things I'm noticing is quite a few start running out of steam in the lower frequencies.I was basically looking for strong to 80hz in these early exercises in output and electrical power handling and also the point where x-max is exceeded.

This is just a point I make when designing my own boxes so take it only as a guideline and nothing more.

I always try and choose a design based around keeping the Thermal and Electrical power up to par at the lowest possible or usable frequencies of the system without hitting x-max.

I'm going to begin posting some system specs with each of the listed drivers.What I'm going to do is work a box/style/load configuration that shows the possible extremes you can get with each suggested driver so you all have an idea as to how they model on the power handling and x-max end of things vs the usable pass-band and overall efficiency.

I've been plugging T/S parameters in designer and hope to be past that point by midday Sunday.

For now off to an afternoon load-in and set up and of all things I get to run lighting and mix at the same time. This should be quite interesting! Perhaps I'll learn how to drink beer with my toes while I'm at it??? Good thing I quit smoking!
 
Re: Coaxial Wedge Collaboration

Ron Kreiger wrote on Sat said:
One of the things I'm noticing is quite a few start running out of steam in the lower frequencies.I was basically looking for strong to 80hz in these early exercises in output and electrical power handling and also the point where x-max is exceeded.
Click to expand...

ha ha ha.... yep, you got it. Flat to 80hz is TOUGH on most pa 10 or 12's. The driver I posted a hornresp for is a 450watt driver with 5mm xmax.... meaning the 50v input I showed is real world. In hornresp depending on port length or distance to front of box you can even get to flat to 70hz.

Let me know when you come up with something close to 100db/watt down to 80hz.... :razz:
 
Re: Coaxial Wedge Collaboration

Rob Timmerman wrote on Sat said:
James Bell wrote on Sat said:
Let me know when you come up with something close to 100db/watt down to 80hz.... :razz:
Click to expand...

The Radian 5312 (used in the original Microwedge) appears to get there, at least in WinISD.

Not the cleanest top end, though.
Click to expand...

Not sure how you figure that, Radian doesn't even rate that high, only 96db/w, and I've always liked the sound of the Radian compression drivers.

The 12'' section does not have very much excursion, Xmax=0.113''.

Crunching a fairly optimium vented alignment shows decent tuning, but the driver is mechanically limited starting at 168hz or so, and by 80hz is 8db limited. If using a vented design, I'd certainly want to use a hp filter around 100hz and not run kick or bass through it.

It looks better in a small sealed cabinet with a much gentler low end roll off(and better impulse response, and some back pressure offering some over excursion protection) and use it for vocals above baritones.

Best regards,

John
 
Re: Coaxial Wedge Collaboration

I've started working on various configs with the suggested drivers.While this is proving to be a pretty large task I am now realizing there's no way I will finish tonight!~ LOL. So I have contacted Jeff to see if we can get a place to store the files as zips. so everyone can just download them and have a good look at all the charts as I finish up each pak.

If I post them here there's gonna be pages full of charts!

If I do 1/2 drivers a day for the next week, by Friday we should have a nice collection of charts and begin discussing where to go from there.
 
Re: DRIVER MODELS

A $450 driver seems like it takes this off of the Weekend warrior's or band running its own sound's plate

I would think the total build cost should be around $500 for the total build, not including labor. The geat thing about the LAB sub was the componant cost was pretty cheap. Granted it takes time to build and the wood is expensive.

Nothing wrong with building a rockin' box but I cant see most guys wanting to or being able to spend much more than $500 per box + labor.
 
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