Coaxial Wedge Collaboration

Re: Coaxial Wedge Collaboration

What I have been able to do is conjure up a box that will accommodate both the B & C and the Ciare however you would need to change port lengths as the LF response will vary between the 2.

I'm going to attempt to outline the differences between these two candidates.

The Ciare will extend down to 53Hz @ -10db and has a 3db down point of 63Hz.It will maintain it's full 350watts electrical power down to 61Hz.

The B & C will extend down to 69Hz @ -10db and has a 3db down point of 81.1Hz. It will maintain its full 350watts electrical power down to 85 Hz.

Neither exceed their x-max at full power in their usable pass band.

Efficiencies are nearly identical as well as are Group Delay and Phase response.

The box size for both is 1.52Cu. Ft.

Vent air velocity is nearly identical.

That pretty much covers the low end.

Now for the HF sections.

In it's favor the B & C has an exponential horn attached but does not list what frequency the horn effectively loads to.

I dont know if the Ciare has a horn attached or not as I can't find a pic showing the front side of the driver but I'm thinking it probably does not as the marketing dept would certainly have been all over that in the .PDF.:confused:

The B & C also includes some polar's which is very helpful in knowing what you can expect when you move side to side from the box.

The Ciare lacks this information as well.

Recommended crossover point for both is 1.2K.

AES Power handling is 110W on the Ciare HF section and 80W on the B & C HF Section.

Both look to have some peakiness above 5K which tells me the manufacturers have chosen not to smooth the hell out of the charts.

Freq. response is nearly identical with a slight edge to the Ciare up at 20K but that's really nothing significant to me.

The exit diameter of the Ciare is 1.4". The B & C does not list the exit diameter or FS of the HF section. Looking at the impedance charts I'm guessing it's as FS around400- 500 and also a 1.4" exit driver. If anyone knows for sure about this please chime in.

While I somewhat agree you can cross the B & C at 1K I also think in order to do so you will need at least an 18db network but it will be at reduced power.

You can probably do the same with the Ciare and it does look smoother between 500-1.2K then the B & C. I think with the right network both can be crossed at 1K. I would be in favor of a tungsten lamp to help keep the HF section out of trouble at war volumes.

The B & C HF is more efficient in it's usable passband and the Ciare efficiency chart certainly does not match the written specs on the HF side from what I see. Looks to me more like [email protected]@1M =/-5db not [email protected]@1m,+/-1.5db?

My Price on the B & C is $462.00 US.
My price on the Ciare is $410.00 US.

I have no idea as to reliability of either of these two units.
 
Re: Coaxial Wedge Collaboration

The B&C HF is 3" voice coil and I presume 1.4 exit. It looks a little better to me and the polars are pretty good for what it is. Of course no mention is made of what frequency the internal b&c horn loads to. I do like the idea of keeping the crossover point quite low as long it can remain within a safe range for the driver. While I did see 1.2K listed as a suggested point, it looks as though the driver should go lower, albeit the horn might have been the limiting factor here. The HF should significantly outrun the LF anyway so there is likely a little bit of room to spare in terms of lost headroom. The lamp is certainly a good consideration.

I wish there were more detailed specs available for the drivers. I'd love to see HF distortion measurements, polars for the Ciare, etc.

Based on the "unknown" factors about the Ciare, the B&C seems like a safer bet. But this is only my opinion, and it certainly would be interesting to compare it with the Ciare. It certainly has impressive LF capabilities, a lower price, and lighter weight..

Presumably we could get a volume discount on drivers if this project came to completion and several people wanted to build some cabs. We might do a group buy or something similar if that was worthwhile for folks.

On another note, Ron, are there any of the other drivers such as the PAudio or the Beyma or similar which might also work reasonably well in your box design, or is accommodating one of the cheaper drivers too much of a compromise?

Thanks for all of the modeling you've done on this Ron, it's a big time commitment, so thank you very much!
 
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Re: Coaxial Wedge Collaboration

The Beyma will also work in the same box as a cheaper alternative with a little difference in the overall freq. response and it's only a 250watt driver.

Again you must change the port lengths.

It also yields a +2.7db hump in response @ 150Hz. and this is the result of getting a lower freq response from the cab and adjusting the HPF to suit.The Ciare has a 2.5db at 96Hz. and the B & C a 1.6 @ 111Hz.The Ciare and B & C yield better frequency response down low as far as the low frequency shaping but the Beyma is still quite usable.

It weighs in at 11.5 lbs.

Here's what it will do.

F3 of 77.5Hz. / -10db @ 59.3Hz.

Maintains it full 250 watts electrical capabilities down to 62Hz.

At rated power it will not hit x-max in it's usable passband.

Vent air velocity is relatively low at full tilt.

Phase response and Group delay are a bit different then the B & C or the Ciare.

In the HF section it needs to cross about 2.2K which is a bit high for a 12" if you're looking for good pattern control.It yields an 1-3/4" VC which tells me it's most likely an 1" or maybe even less exit driver. I doubt 1k cross is possible with this driver.

My best guess is HF response is a bit of a compromise but again this is a cheaper driver so depending on your needs it will work well.

It's a compromise in Low end response and HF output and most likely directionality as well.

Regarding the P-Audio or Eminence drivers.They dont model well unless you are willing to accept a very high F3 and diminished power handling. I would not consider them unless someone can show me good cause to do so.

The RCF at it's price point simply doesn't offer any more positives then either the B & C or Ciare.I'm sure it's a decent unit but the other two are hard to turn away from.

I know earlier in the thread J Bell came up with a horn load as well. Compared to the reflex solutions the horn will give you a bit more output in the passband but also in a fairly bigger box.

I modeled the Ciare in the same Horn Box as J-Bell choose, changing the TS parameters, rear chamber volume and the porting and I can get a similar response as in Designer with the reflex design.The difference of course would be the box size.1.52cu. ft. vs 2.1cu. ft. or so. Now that only includes the actual horn volume not including adding outer side walls to mount the horn into.

If James wants to model either the Ciare or the B & C I'd be curious to see the results in horn loads actually tailored to those drivers since we already know in reflex they behave pretty well down low..
 
Re: Coaxial Wedge Collaboration

A 2.1 cu ft horn wedge is a little bit larger size than I'd find to be ideal - something relatively compact and low-profile I think is going to be important to most folks - look at the popularity of such designs these days, like Microwedge, SRX712M, and the many other compact coaxials out there. Is the added output of a horn really necessary anyway given the relatively good predicted performance in the reflex setup?

That's good re the Beyma working as a cheaper option.

Any other thoughts re the box angles? I liked Robert's (Syd) suggestion of an approach similar to the QSC CSM series, with angle adjustment hardware built into the unit rather than a box with 2 separate wedge angles. Not sure if there is something off the shelf that could be similarly integrated here? Photo attached as a reference.
 

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Re: Coaxial Wedge Collaboration

Not having heard the dispersion pattern of arc/clusters of "slices"...
Perhaps someone can clarify a question - in order to minimize interference in these clusters doesn't each slice have tight dispersion to minimize overlap?

Is it possible to find a sitable driver ( w smaller Vas ) for a version smaller than 2.1 ft?

Another concept that QSC patented was designing the port in such a fashion as to used as a grip. Using traditional tube ports do not facilitate grabbing, But nothing keeps a DIYer from creating one that does
 
Re: Coaxial Wedge Collaboration

2.1cu. ft is for a horn loaded wedge not the reflex design. Reflex design is 1.52 cu ft which is roughly 17" deep x 17'" high @ the back and 16" wide @ the back x 12" wide @ the front and 7" high @ the front in a wedge shape. That is a preliminary shape as most likely I will drop the back height and increase the length a bit. Maybe even the width as well.As it stands now 1.52 cu ft isn't that big of a box especially considering the possible LF response.

The only real advantage with the horn load is some efficiency gain between 200 and 500Hz +3db with the hump at about 400hz in the horns loading passband but given the size increases I dont see it as a viable option.A 400hz hump in response is probably what I dont want in a wedge?? In fact that's usually an area of cut for me so the added output would be just another point of EQ to fix the response.Of course different environments will vary those results but I still like to process the box out of the chute and simply tone first and graph second during sound check.

I'd be curious as to others approach to dialing in wedges and what they would want from the wedge in raw response.I'd like to include some DSP processing parameters after testing but at the same time have the box do well in passive mode.
 
Re: Coaxial Wedge Collaboration

As it stands now 1.52 cu ft isn't that big of a box especially considering the possible LF response.

Yes, I think this is a pretty reasonable size given the response.

I'd be curious as to others approach to dialing in wedges and what they would want from the wedge in raw response.I'd like to include some DSP processing parameters after testing but at the same time have the box do well in passive mode.

I agree with your thoughts re midrange response, I'm often cutting something in the 400-500 range and really don't need a ton of sensitivity in that range.

Regarding processing, I'd suggest that if a passive crossover is used, that it lean towards something fairly flat, and have a DSP based biamp preset that approximates this response. This would work well for general purpose use, for example if you wanted to use the wedge as a front fill or for similar alternate duty.

I would then suggest having a biamp preset that is "tweaked for typical monitor duty", which offers slightly better GBF and a few minor tweaks that are a good starting point for monitor use.

This seems to be a recent trend, I know EAW publishes several presets for the MW line, and I like this idea.

Of course any processor settings need to take into consideration the sometimes significant differences between different mfr's DSP units running the exact same settings. No point in worrying about this yet, though.
 
Re: Coaxial Wedge Collaboration

Considerations:
At the onset Ron indicated that subject to discussion were criteria including:
System Configuration ie: Bi-amp-able/Passive/Both, Polar Response
From a design perspective: Don't many of these criteria have to determined perhaps quantified?
My take is utilizing a passive crossover will define/place limitations/considerations in design; Driver selection vs a bi-amp design which allows lower xover points and signal manipulation. Active expands the driver selection options not viable for passive.
RE: Polar response - Some here are familiar with the approach taken with the BF monitors - Wide dispersion with a non-linear response intended to "pop" the vocals through the mix. Basically non-flat.
It appears that consensus here is for a flat ( neutral? ) FR,
But what about wide off-axis? Practically speaking what impact does it have on the stage level or in bleed into adjacent mics?
A pitfall ( I see ) is attempting to make a multi-use monitor and having severe compromise for flexibility.
Swiss Army Knifes are handy ( been using them for decades ), but they are not a replacement for a dedicated Knife, or screwdriver or etc.
I tend to be a form follows function advocate and wonder if it would be better to define performance and other criteria and optimize to that.
 
Re: Coaxial Wedge Collaboration

Valid points for sure.....

I'll spare you from sharing what I think of fitz's monitor designs. Suffice it to say that I do not have any desire for those "features" in a wedge.

Regarding wide off axis response - while in some circumstances this is desirable, I often personally am in situations where there at least 4 or more monitor mixes, often in fairly cramped stages with fairly loud stage volumes. Mic bleed is often a concern that must be dealt with. In those cases somewhere in the 60 to 80 degree range is plenty wide for me. If some muso is a "wanderer", I'd rather have to run 2 wedges than have one that's too wide. Given that the box size is not huge, an extra box shouldn't be a big concern most of the time.

But that's just me and my usage is not necessarily representative of others....

Also, personally if I were to use this wedge, it would always be bi-amped. The passive crossover would be something I'd only use very occasionally, so if I were to build these wedges, it would be something I might choose to omit myself. I expect that designing a high quality passive crossover would be tedious and expensive to do "right". Someone like Curtis List (Too Tall) could likely assist in this. Of course it could always be looked at as an afterthought, design around DSP first and then worry about a passive option later. It might hamper consistency between biamp and passive performance, but I guess it depends on how much of a priority that consistency would be for folks. I'll leave that for others to decide, because my opinion matters little in that regard.

Agreed re the need to avoid turning this box into a "jack of all trades, master of none". It's primary focus should be a wedge. If it can be easily used for SOS/fill applications, great, but not at the expense of its primary goal.
 
Re: Coaxial Wedge Collaboration

Some very good points Robert.

I'll approach a few point individually. Of course from my own perspective or madness whichever you prefer!

:I'm certainly not looking to create the end all of wedges here.DIY,affordable by the average Joe who can build things,good output,the right coverage,and most importantly good sounding.Basically looking to get a step above the better MI gear out there and stay with the lower end of the big boy toys without taking a second mortgage.

dispersion or off axis reproduction particularly in the hi-mid to high frequencies.

While most performers dont care for being in the vise when it comes to listening to wedges most sound guys dont like spill either.My take has always been along these lines.I can use multiple wedges to gain width in coverage if I need to do it. I simply cannot stop a wide axis spill from intruding another space on stage. I know it increases the hardware count but at least I can get where I need to go.So in my world a more narrow coverage up top is a better overall fit but not so narrow that you cant scratch your ass and loose your vocal!

Of course YMMV so that's why I was looking for input from others as to what they expect from a wedge.

I agree that from a design standpoint some things need to be laid out in advance but lets face it,the industry is inundated with cost effective DSP and most people even weekend warriors doing speaker on a pole use them.I'd have to insist this is the norm and no longer the exception.

:"Active expands the driver selection options not viable for passive"

Most definitely but these drivers will function nearly the same with passive 12dbLow/18dbHigh and perhaps a few other things in there to make the response pretty good.There will be some compromises as the passive box would be missing the HPF so the low end roll off will change.However the basic designs as they sit now will work well without the HPFs and better with them.I did all modeling before adding the HPFs!

I started modeling a passive network but fear this will be a test,retest and test again process when it comes to actually producing the network.My skill set is more limited in this regard but I'll work through it.

Anyone with crossover design experience feel free to jump in and have a go at it.I will send you any of the information I already have.

:Flat or not so flat!

As flat as possible tested in an open field with the raw design passive or processed.

From that point on you simply do as many do and tone and eq the box for each environment you encounter.I never leave a box flat sounding or attempt to flatten a curve in a live environment. It just never sounds good to my ears. If that goes against what others believe then so be it.It's worked well for me.

DSP settings.

Upon testing we can certainly determine different usage scenarios and adjust DSP settings accordingly.First and foremost it's a wedge.Anything else we can squeeze out of it becomes a bonus point to consider when deciding to build it.

:regarding driver selection.

Since it's a "coax" design the choices of pro level coaxs out there are relatively limited.While different forms of making a coaxial arrangement can be utilized such as horn loaded bottom and mouth loaded HF section or even the use of planners I have found it difficult to design around these parameters without getting very component specific and spending a whole lot of time on modeling one component.Not that I dont want to use horn response etc. and start looking at a lot of different possibilities.I dont have that much time and the current process is eating up a fair amount of time as it is.

Anyone else wishing to contribute their time is modeling different configurations feel free to chime in.If what you present to us is viable we will certainly concider it fully.

Different manufactures DSP responses.
I really dont know how to approach this at all.:?~:-?~:???:If I produce settings with a Drive Rack 260 or Ashley Protea will your Xilica or Peavey or Behringer give you the same results?

Most likely I will try and get a hold of as many DSP's as I can and produce the settings necessary and include them. I could also just ship the box out to anyone who wants to test it and make a DSP setting for it after I have exhausted all my personal resources.:D~:-D~:grin:
 
Re: Coaxial Wedge Collaboration

Different manufactures DSP responses.
I really dont know how to approach this at all.:?~:-?~:???:If I produce settings with a Drive Rack 260 or Ashley Protea will your Xilica or Peavey or Behringer give you the same results?

Absolutely not. The differences can range from very subtle to quite significant.

I would suggest that once we decide on settings, we publish a screenshot of the measured ELECTRICAL response from the DSP used to derive the settings.

We can then get a few folks to try to reproduce this electrical response on their various DSP units and see where the differences lie. This could be done without having to have the wedge at all, just measurement software and a DSP, so it would be easier to get multiple DSP's tested this way. We could suggest alternate product specific settings if there are some DSP's that are considerably varied. I wouldn't want this to turn into a can of worms though.

Bennett is doing research on this right now, perhaps he'll have some guidance on this later once we get to this stage. Also Rich Frembes has TONS of experience developing product-specific settings (he's with Fulcrum acoustic), perhaps there are some generalizations he could share.

Let's not worry too much about this right now, it can come later.
 
Re: Coaxial Wedge Collaboration

I'm using Passive Crossover Design 7.It's a nice spreadsheet program and not the standard everyday plug in the wanted filter vs impedance java applet on the web! It's developed by Jeff Bagby and requires Excel with Macros Enabled.

http://audio.claub.net/software/jbabgy/PCD.html

Jeff has developed some very useful audio apps so take a moment and visit his web page.

I realize I didn't answer your question directly Robert regarding "classic Textbook values" Yes textbook to start.That's part of the program.You can then modify the values based on available components later and see the results.
 
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Beta testers

Looking slightly to the future, it would be nice to have a few people get their hands on a prototype whenever one is built and put it through a few paces to get some input regarding things like suggested changes to the design, DSP settings, etc, etc. This is still quite some time away, but I'd like to get some organizational stuff in motion.

You won't necessarily need Smaart experience (though it wouldn't hurt), but it's preferable for this to go to folks with experience on a wide range of products who will have a pretty good frame of reference for commercial offerings. All I'd ask is that you be able to chip in some $$ to help cover the cost of shipping a test cab to you, given that there is no budget for this project, so all incurred expenses are pretty much out of the pocket of those directly involved.

We'll need to limit this to folks in the USA to keep shipping costs low.

PM me if you're interested.
 
Re: Beta testers

What about Canada since you Jeff are already there.It's not a bother for me to meet you upstate NY and hand deliver then once in Canada you can also ship it around up there.I'm in the NE so anywhere up to about NH and down to DC is easily doable. As far west as Ohio etc.Once it gets to those destinations then perhaps it can be moved further no? I do think however where ever it ends up it must be with the stipulation that it doesn't get held in one place too long.Say maybe no longer then 2 weeks.Of course depending on how many apply we could move that figure around.Just thinking out loud.
 
Re: Beta testers

I am late to the party and while I don't have much to add I do have a few comments.
I like the weight of the drivers you are considering. My monitor rig is all coax 12" cabs. The driver is a B&C 12CX32 which weighs a boatload making the completed wedge over 50lbs. I love the sound of them but do not like to move them at all. The driver sells for around $400 which is in the same range as yours and the B&C crossover for it is about $85 (I just replaced one).
So, with the nice 11lb or so driver you have, don't make the cabinet 40lbs.
A lot of weekend JV types like the JBL 12" wedges cause they only weigh 30lbs. Of course, from what little I understand of these things, at least the coax wedges don't have HF pattern flip to contend with.
Hell, if I could get neo drivers for my wedges I would love it :-)
 
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Re: Beta testers

When you guys get one together I will happily roll DSP settings for it, passive and bi-amped.

Thanks Bennett, given your extensive measurement and tuning experience this would be a real asset. Additionally some insight into dealing with the variety of DSP's and some sort of estimation as to how those settings might transfer across different common DSP's would be invaluable.

Regarding Ron's questions about Canada, I was thinking it might be easier for me to source the driver up here and have an UNLOADED box shipped to me. That would keep the cost and customs "value" complications easier to handle, as an unloaded wooden box has little value. There are a few people up here on these forums who may want to participate.
 
Re: Beta testers

with the nice 11lb or so driver you have, don't make the cabinet 40lbs.

Indeed it should be possible to make something reasonably lightweight. However, at the same time, I'd suggest that we not allow the weight desires to limit the ability to build something rugged. Hopefully there is a happy medium here.


On another note, has anyone got any further thoughts to suggest regarding box angles and the proposed "adjustable feet" idea? Anyone know of appropriate hardware for this purpose? Would simple furniture leveling feet work, or is that too simplistic? http://www.vibrationmounts.com/RFQ/VM110720.htm
 
Re: Beta testers

I'm going to begin posting some cabinet designs over the course of this week and next.Anyone with ideas as to how,where and what to improve upon please chime in. Basically shapes and angles. I'll do the same as the charts and Jeff can post up the zips. I'll convert everything to .jpg so no special software will be needed to view the files.