[Dmason]

The ONLY thing stopping me from the Irises: no cast baskets; Key issue with OB drivers, free-standing, etc. Maybe I am wrong, but I don't feel the same about adding superlative compression drivers, mylar diaphragms, active crossing, triodes and T's, and having stamped baskets sagging, and ringing. Is this a legitimate concern?

On the other hand, the only other coax driver that even comes "close" to acceptable is the Ciare with Qts .52, which is low, and at twice the price.

I will suspend judgment until I can compare with the prototype Hemp OB drivers Qts .75, but even that is a different colored horse. There aren't alot of choices. Hemp coned 10 inch coaxial with universal 1 inch throat would be interesting...that would be my personal wish list choice for this schtick.

[Bob in St. Louis]

The ONLY thing stopping me from the Irises:.................

For the cost of the sales tax of highend drivers, $300 would be money well spent.
In this hobby, with the level some of us are at, that kind of money is a drop in the bucket. You've probably got IC's that retail for more than that, right?

Give it a shot, I don't think you'll regret it. If for some reason you just can't live with them, someone WILL buy them from you. You wouldn't be out much at all.

Bob

[Dmason]

Bob

I didnt know Home Depot sold interconnects! 

I appreciate your point, it is not lost on me, and I do not disagree, but I know the difference in sound, and I would be investing far more than the cost of two Iris drivers, for what I am mulling over. I am looking at a potential commercial product here, just some ideas swirling in my head right now, based on some of the stuff I have learned along the way.

I am highly impressed with the Jamo, both from an engineering standpoint, and aesthetics, and can see room for obvious improvements, and room to drop the price of a potentially improved product by about 75%, and come up with something great for the masses, targeted for regular blokes like me, who just want some good sound, and something that looked good was a bonus. And I have a wish list in an OB-specific coaxial driver. John H, I hope you are reading.

[Bob in St. Louis]

I didnt know Home Depot sold interconnects! 

I followed and understand every thing you said, except this. I've been staring at it for several minutes now, and smoke started coming from my ears. 

Bob

P.S. By the way, they do sell some. Nothing fancy. And oh, you do have to DIY them.

[Dmason]

Bob -- HD sells alot of wiring perfect for audio. High Definition, Home Depot, Hard Drive, HD for me. My point was that I would NEVER blow $300 on interconnects when there is Home Depot, Cat 5, the rest. I can solder, do, and so am not a great candidate for all that other stuff.

[hurdy_gurdyman]

The ONLY thing stopping me from the Irises: no cast baskets;

Hey Dan,

Darrel has actually talked about making cast frames and silver wound voice coils available sometime. Just not sure how soon this would be.

http://www.hawthorneaudio.com/forum/viewtopic.php?t=391&start=30

In the meantime, wrapping the frame legs tightly with Mortite or plumbers putty makes a noticable improvement.

Dave

[Dmason]

Thanks Dave, I appreciate that, but for exposed drivers, or for some quasi-commercial venture, no one wants putty slabbed on those. The Eminence DeltaLite baskets are some of the nicest around. They can do those to order, AND, they have Tone Tubby hemp 12's for the Cannabis Rex, and Tone Tubby have 15 inch cones for JBL 2115 et al, and the cone geometries are easily adapted, according to John Harrison.

I see Darrel has the same wish list as me, so that is encouraging

[JohninCR]

Dan,

You can always just damp on the inside of the spokes of the basket frame.
My issue with the stamped frames of a very exposed driver is how it looks. 
Free air flow and ringing are secondary.  I'd much rather look at a basket like
Adire's old DPL12, or some of the vintage 4 spoke cast baskets.

[Bob in St. Louis]

My issue with the stamped frames of a very exposed driver is how it looks. 
Free air flow and ringing are secondary. 

I never thought I'd see the day you would say something like that John.

It's ALWAYS about the sound.

Bob

[notech]

My issue with the stamped frames of a very exposed driver is how it looks. 
Free air flow and ringing are secondary.

I never thought I'd see the day you would say something like that John.

It's ALWAYS about the sound.

Bob

Was that the first indication? 

The first tip off for me was Johnny's apparent lack of fundamental understanding of what the purpose of a baffle is.  If he understood this he'd realize why building a no-baffle speaker will not work well (not a problem if he's not interested in how it will sound).  The next clue was he seems to not understand what the difference is between an open-baffle and dipole radiator (they aren't the same).  The list goes on from there...

I'm somewhat surprised that nobody seems to see these and other issues presented in this thread given the wealth of speaker design information readily available on the net.   

[Brad]

Notech,

Welcome to Audiocircle.
You may have set a record for offending the greatest number of people in your first post!!!!

Say what you want, but keep it friendly.

[Bob in St. Louis]

Dude, you not off to a good start.
John is a very respected speaker builder/designer on numerous forums.

As far as, "wealth of speaker design information readily available on the net"....
Are you refering to OB speaker design? If so, I'd like some links.
If your talking about speaker building in gereral, I'm not interested.

Word to the wise, notech ....... well never mind.

Bob

[notech]

Notech,

Welcome to Audiocircle.
You may have set a record for offending the greatest number of people in your first post!!!!

Say what you want, but keep it friendly.

Thanks Brad.  As you can see I don't frequent this site much.  That said, I was horrified by some most of the information contained in this thread.  Being a moderator, I assume your role is of a traffic cop nature?  I ask because some of the other sites that I frequent have technical moderaors.

To Bob: In my book being able to operate a router doesn't qualify one as a speaker builder.  Others' may have different ideas.

[hurdy_gurdyman]

The first tip off for me was Johnny's apparent lack of fundamental understanding of what the purpose of a baffle is.  If he understood this he'd realize why building a no-baffle speaker will not work well (not a problem if he's not interested in how it will sound).  The next clue was he seems to not understand what the difference is between an open-baffle and dipole radiator (they aren't the same).  The list goes on from there...

I'm somewhat surprised that nobody seems to see these and other issues presented in this thread given the wealth of speaker design information readily available on the net.   

First off, if you read John's post on a half dozen different forums over the last year or two, you'll discover that he does, indeed, know what a baffle is for, probably better than most of us.
Second, there are large drivers out there that sound pretty good with little or no baffle at all. Several people here and on other forums have been discovering this lately.
Third, there is a lot of outdated information on the net about OB's. More and more is being discovered, especially concerning matching drivers to baffles. One formula does not fit them all. Do some more research. There are several approaches now to making a good sounding OB.

I, for one, am highly interested in what John's experimenting produces.

Dave

[Greggo]

I think there is at least some good evidence supporting the "no baffle" approach.

The first thing that comes to mind is an old interview with Richard Vandersteen in which I clearly remember him saying that when they first started testing drivers, and he tested a lot of them, they would often just hold them up or mount them to a bracket (or something  like that) and just listen to the driver as naked as possible to get a sense of its most natural state, and that in almost every instance, he and his crew would prefer the sound of a driver naked than mounted to any size/shape of baffle.  That comment stuck with me and I think of it everytime I see pics of his mid/tweeter mounts on his various speaker designs and also when people talk about baffles.  I guess it is also fair to say that most of us know about the whole wave-length versus pi radiation space and how that creates natural points for baffle-step work etc... and about edge diffraction, and also the path length for dipole cancellation etc...  I have seen a couple of commercial designs, can't remember where.., that use completely open driver mounts (rings and brackets that barley add more surface area than the driver frames and baskets themselves) and would love to hear something like that.

Even at the lowest ranges, I remember reading something about the "made to order only" magnet/motor/coil assembly from Adire that you could mount a piece of plywood to or something insane like that and still get incredible response.  So the notion that one could go all the way down to 40 hz or lower with big drivers just propped up on the floor or suspended from some kind of framework that is very rigid but offers no significant surface area to interact with the drivers wave launch, is all stuff I am certainly open to....

Regards,

Greg Jensen

[notech]

Hello Greggo, As you know, Vandersteen speakers have their drivers mounted in a box.  If Richard truly believed that mounting drivers "naked" was better (to "hear them in their most natural state") don't you think he'd build his speakers that way?  He's a pretty smart guy and uses some pretty sophisticated hardware/software to measure and model his designs. 

Contrary to popular belief, a driver will not perform anywhere near its best response w/o being mounted to some sort of baffle (regardless of its Qts of the wavelength it’s trying to reproduce).  If you don't believe this after reading some of the work published by several well respected designers, you can always find this out for yourself.  Investing in some measurement equipment and measuring some of the effects that are being discussed in this thread would likely steer you in a different direction.  In fact, there are baffle simulators available (for free) that will also show you predicted response of a free air driver Vs one mounted on any size baffle (sealed box or otherwise).

Instead of using a CAD program to design pretty pictures, why not use the appropriate tool(s) to design something that will perform properly?  It doesn't require any additional work.

[Dmason]

Whooo is this guy?? You just demonstrated how little you know about Vandersteen's approach, which I am not going to get into, and coupled with your strident and condescending tone, I am now more interested in psychiatry.

   WTF!!

[Greggo]

Notech,

Not sure what it is that you were looking for when you arrived at audiocircle, but whatever it was, you will surely not find it here.  Please live and let live, and find another thread to spout off on.... It's not that different opinions are such a bad thing, but you are clearly all too happy to just step on ideas with your own version of information that obviously falls into the "uninformed" category.  Even then, something that might be acceptable were it not for your obnoxious tone.  Good day and good ridance.

Regards,

Greg Jensen

[Russell Dawkins]

To Bob: In my book being able to operate a router doesn't qualify one as a speaker builder.  Others' may have different ideas.

rude, semi-literate (others does not have an apostrophe), and ill-informed.

Dalquist DQ 10 had essentially no baffles for the mid driver, Gradient had a 12" mid driver with no baffle with the null (oops I guess it couldn't have a null if it wasn't dipolar) aimed at the floor to reduce floor bounce.

Speaking of dipoles, what do you, notech, see as the difference between a dipole and an open baffle, since you raised the point in your first post. I think we all understand that a cone driver in an open baffle is not dipolar through the higher frequncies. That, I would have thought, went without saying.

[JohninCR]

NoTech,

Please make some specific points and I'll be more than happy to debate them.
I like debating.

If you think a 15" driver with a .9 Qts mounted near the floor with no baffle can't
make bass, then you just haven't tried it.   The +6db of the floor effect offsets
a full octave of dipole cancellation, which is the same as doubling the baffle
diameter from the inherent 15" baffle of the driver itself.  I have no interest
whatsoever in putting a 30" wide reflective surface pointed at my listening position.