Coaxial Wedge Collaboration

Re: Beta testers

I'd be willing to make a couple cabs and help refine the construction plans and directions when it gets to that stage. I have your standard woodworking tools and have designed and built speakers and furniture before. Though, I won't really have a free weekend till the middle of May (hooray for work flooding in over the past two weeks)
 
Re: Beta testers

First post, interesting thread. For a no holds barred coax you might look at the eighteen sound 12cx800. Not exactly a cheap option MAP is $620. Full disclosure, I'm an eighteen sound dealer, a really new dealer. Still familiarizing my self with the line and it's specs, so take my suggestion with a grain of salt.
 
Re: Coaxial Wedge Collaboration

Ron Kreiger said:
I'm using Passive Crossover Design 7....http://audio.claub.net/software/jbabgy/PCD.html 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.
Click to expand...
Since I wasn't able to get a definitive answer from Jeff:
I guess I would ignore additional calcs parameters or "frame/bracket" a couple around a null/default value.
Then comes measuring/listening/tweak repeat...
 
Re: Beta testers

Rob Spence said:
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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Points well noted.Since Charles chimed in below I might just take him up on his offer.I'm all for light weight.In fact I'm in the same boat as you. All my wedges are heavy. EAW SM159zi 54lbs., SoundBridge 12" Slice Copys 50 lbs.,Old Sunn SPL12" 2-way 48 lbs. so a nice light coax is for me and I'll e-bay the rest of the flock!
 
Re: Beta testers

The 18Sound models almost Identically to the Ciare as far as LF response (Ciare will go lower but only a bit) with a tad more output SPL wise but not much. At it's price point $200.00 more then the Ciare that's a deal breaker for me unless the Response in the HF area is a great deal different.Jeffs B&C with the Exponential Horn attached just might be the HF edge in the project so that's pretty much where we are sitting at the moment.I've been running the numbers with a passive network and looking closely at Phase response etc.For now I'll include the 18Sound just to see the HF response with a passive based solely on the manufacturers literature regarding the HF out scheme they use.

This last feature reduces the inductance figure of frequencies above 10 kHz, improving phase and impedance linearisation.
A specific dedicated horn’s throat design has also been chosen by Eigtheen Sound engineers, maximizing the cone’s profile coupling.
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This catches my interest as far as HF output is concerned.So with that I will do a passive model to see if there's any advantage to that.

Again at a considerably higher price point the Ciare and B&C keep up rather well.The Beyma is a nice low cost option so I might build that one last just to see how it fairs out.

What we might be able to do Leland is ship you a completed box and let you mount and test the 18Sound. I'd have to see how well it models in the same box as the Ciare and B&C but from what I ran earlier it appears that it will do fine in that box.

Can you do polar testing with SMAART? We would be interested in polar's not just on axis results as well as phase and group delay if you could do it.You can PM me back if you wish.
 
Re: Beta testers

Charles Harrigan said:
I'd be willing to make a couple cabs and help refine the construction plans and directions when it gets to that stage. I have your standard woodworking tools and have designed and built speakers and furniture before. Though, I won't really have a free weekend till the middle of May (hooray for work flooding in over the past two weeks)
Click to expand...

It would be great to have you help in this way, thanks for the offer! That timeframe is no problem anyway as I expect we're still a fair distance from thinking about making sawdust yet.
 
Re: Beta testers

Ron Kreiger said:
Can you do polar testing with SMAART? We would be interested in polar's not just on axis results as well as phase and group delay if you could do it.You can PM me back if you wish.
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You can "kinda" do polars by using the spectrgraph and attaching a string at a center point on the loudspeaker to use as a distance gauge and walk around the cabinet.

Now ground reflections and such will enter into the equation, but you can get an idea of what is happening.

There will be no angle numbers associated with it, so you have to know where the start-stop and center points are on the graph and how far off axis you were during the measurements.

I like to tap on the head of the mic for each of the start-middle-stop locations to give a reference for later on. It shows up as a nice large spike in the level.
 
Re: Beta testers

I don't have the software. I've just been using some freebies from the net for basic stuff. I've been shopping it for 2 years, I keep looking at various packages. It's just a matter of the roundtuit. And finding the time to justify the purchase. Maybe this year. But I'd be willing to ship a driver.
 
Re: Beta testers

Ron Kreiger said:
Points well noted.Since Charles chimed in below I might just take him up on his offer.I'm all for light weight.In fact I'm in the same boat as you. All my wedges are heavy. EAW SM159zi 54lbs., SoundBridge 12" Slice Copys 50 lbs.,Old Sunn SPL12" 2-way 48 lbs. so a nice light coax is for me and I'll e-bay the rest of the flock!
Click to expand...

I don't know, those sound pretty light to me.
 
Re: Coaxial Wedge Collaboration

My take on it: prototypes rarely look like the final form.
A test box can be crude and heavy and any passive xover externalized during testing.
Ultimately more finished: ALAP ( as light as possible ) without compromising on durability and free from buzz and resonance.
 
Re: Beta testers

Leland Crooks said:
For a no holds barred coax you might look at the eighteen sound 12cx800. Not exactly a cheap option MAP is $620. Full disclosure, I'm an eighteen sound dealer, a really new dealer. Still familiarizing my self with the line and it's specs, so take my suggestion with a grain of salt.
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Hi Leland,
Just getting back to you again about this.
I previously suggested that this driver is probably a bit too expensive for most DIY'ers. It certainly would push the overall DIY cost well into the range of some pretty solid performing commercial cabs.

It's also not just a matter of "drop it in" - that would work reasonably but not fully take advantage of the design, so I'd suggest that we exclude it from consideration as it may make the prototyping process more complicated and with a driver that may be priced outside of "reasonable" for many DIY types.

Thanks for the suggestion though and your offer. We'll certainly keep 18 Sound stuff in mind for other projects .
 
Re: Beta testers

Hello All,

First off, some here know me, including Bennett, but I should introduce myself to those that may not know.
I am the BMS distributor for North America. So, everything that I say has to be predicated on that.

1) The wedge that went to the shootout was a CIARE/BMS hybrid. (pronounced CHEE-ARE-AYE)
There was no horn on that coaxial.

2) I no longer have an association with CIARE. (I have some living dead web pages that don't want to seem to die.)
I do have some old stock I am getting rid of, but have not imported anything for maybe three years. Al at US Speaker is the only place to buy CIARE in the US.
I am sure there are a lot of places in Europe where it is much more well known.

3) Although I hire Curtis List to design and build my crossovers, Curtis is not married to BMS, or Assistance Audio. I hire him because he is the absolute best that I have come across.
I cannot emphasize this enough. No matter which speaker you go with, you need to hire Curtis to do the crossover.

All of the manufacturers who buy BMS from me in quantity have one thing in common, a great crossover person.

Even if I did not sell a single component, or accompanying crossover, having him do my crossovers just for my company would be worth it to me.

4) (Number 4 is just for more emphasis.) Our set ups are now, Digital board > Amp (single channel per mix) > speaker.
EQ set flat, check with mic to make sure we have signal.

Leland, I am guessing that no matter which driver they go with, you will use the 18 sound. Same story, hire Curtis to do a crossover for you.

5) Passive crossovers done right will not be cheap. If you think the hit for the speaker components is high for a weekend warrior, the passives will give you more pause.
It will be over $160 for Curtis to build you one for the BMS 12CN680. I know this seems high at first, but when you hear what he has done, and realize what it is replacing,
it makes financial sense. This is not going to be a plug and play from Parts Express.

6) I applaud the progress you have made. When this came up on the old LAB i thought it would never get off the ground. Too many variables.
I like that you are going with the 12" coaxial. To me this is the best of all worlds. For one thing, the biggest buggaboo otherwise is going to be the horn, and ensuing use of.
SO many variables eliminated. EG, horn on top for more symetrical sound, or on the side for lower profile?

7) I would suggest some variables be left flexible. In a quick perusal, I have not seen cabinet angle(s) (I use two) mentioned yet. I think it would be wonderful to have a set of plans,
and CAD drawings that anyone could take to a local shop for part making. I also think that one should think of the use for themselves, and if the agreed upon angle is not suitable, go with your own.
The main thing is going to be size and porting. Even this could be changed for personal preference for say a certain bass singer.

8) Another possible variable is to have a ceramic option. All models mentioned have been neodymium, which not only is lighter, but sounds better.
But it is also much more expensive, across the board. I would guess that the other speaker companies have a ceramic version of their coaxials.
This would also mean another version of the accompanying crossover.

9) A name. For those of you that need to fill riders, a name is going to be key. For one thing, you can't be saying "its something I built", even if it is "something you built".
Having another name to hang it on, white papers, and design engineers, maybe even its own web page, will go a long ways to selling its use to (potential) customers.
No, you can't call it the Coaxial Wedge Collaboration.

10) If you want to consider the BMS 12CN680, it sells for $411.
Also, I have had groups on forums purchase from me as a single entity for a discount. 12 pieces= 15% discount. So as long as the money comes from one place, I have shipped to multiple addresses.

I also have one in a cabinet that I send out to listen to if you pay the cost of shipping.

11) In my quick read through of this thread I did not see anything about witches hats. I think that having the option of this on a stick for small things, or on a sub for medium/small (relative to who you are),
the 12" coaxial is a great way to go for single cabinet house applications.

Regards, Jack Arnott
(Assistance Audio)
 
Crossover design choice - seeking your input!

In some of the discussions surrounding implementation of a passive crossover in the coaxial wedge, there are some general considerations, and an idea I would suggest as a possible alternative which I would ask for everyone's input on.

Building a full passive crossover which implements not only the crossover itself but a variety of other processing to optimize cab response is typically quite expensive, time consuming, and is difficult to design.


As an alternative idea, what about this?

Implement a VERY BASIC simple passive crossover, but mandate that the coax wedge requires DSP regardless of whether run biamp or passive. In passive mode, a single channel of DSP provides the necessary remaining optimization.


This is similar to the approach many companies use to great effect (Nexo for example).

Advantages:
Reduced crossover cost per cabinet (assuming you have existing DSP available)
Reduced physical crossover design complexity (and easier long term support/troubleshooting of XO parts)
Potential for more processing/optimization capability

Disadvantages:
Requires one channel of DSP, either via processor or onboard power amp DSP for each monitor mix.

My thoughts:
I'm already using amp DSP for all of my passive monitor mixes for HPF, limiting, and general eq optimization. If you already have the available DSP, this works out great.


That's my take on things......

How about everyone else? Does this seem reasonable to require at least one DSP channel for processing given the advantages it brings, or would that be a total no-go for you?

Please share your thoughts!
 
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Re: Crossover design choice - seeking your input!

Jeff,

The problem is you're going to have to specify not just a channel of DSP, but a specific DSP. It is unlikely that everyone interested in this project will share a DSP platform.

I suggest that crossover design, and by consequence driver selection, will be the make or break for this box. I really, really liked the wedge at WedgeFest. Although it didn't have the output of other 12" coax wedges there, it sounded really great, was light, cheap, and took a beating well. It did have a hell of a lot of crossover inside, though.

You're going to have to provide enough crossover that the box can be used "out of the box", so to speak, and offer DSP settings for specific platforms so that another 3dB or so can be squeezed out of the box... having a HPF will make a big difference, and that's probably impractical passively.
 
Re: Crossover design choice - seeking your input!

Hi Bennett,
Ya, I know, though I thought that using an approach of supporting common DSP's by posting a desired electrical response and getting folks here to try to match the electrical response in their own DSP's to help us come up with multiple platform specific dsp's might be an answer to that. A lot of legwork for sure, but it may be worth it when you consider the cost and complexity of a crossover similar to the BMS wedge you mention from WedgeFest. I am somewhat hesitant about us getting into a passive XO of that magnitude, as it might end up being very reliant on an external source.

Considering that you were able to do something similar for your DSP Tower of Babel article research, I think it's certainly possible.

You've weighed in, I'm hoping others will too.
 
Re: Crossover design choice - seeking your input!

I would not want to go to the trouble of building this unless it was a potential Cadillac monitor and weighed less than 50 lbs (preferably less than 40). No interest in skimping on the crossover or speaker component, in biamping, or needing serious DSP to make it work right. I figure if I could build one of these for less than $1k and get performance in the neighborhood of a microwedge that cost double, it would be well worth it. Maybe we could have 2 versions - the economy wedge with a cheap coax and a simple crossover network, and a pro wedge with all the good stuff.
 
Re: Crossover design choice - seeking your input!

Thanks Rick, your input noted, we are at 2 votes to 1 in favor of doing a "serious" passive crossover. Maybe this should be a poll, though I'm not sure if polls are possible on VBulletin within existing threads? Anyone?
 
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