[brj]

Danny, any idea what benefits or difficulties might arise if you tried to use a cylinder instead of a box for the cabinet?  I would think you could use concrete forms or even PVC pipe, with the only difficulty being the cutout needed to mount the tweeter.  There isn't much baffle in the first place, but such a built would eliminate even that.  It would also be quite clean looking...

Edit: I just followed the Pluto link and see they did the same thing, but with a different tweeter mounting.

[klh]

Danny... I'm concerned about placement. 1st, when you talk about 3' from the wall, are you talking about the tweeter, or the rear of the enclosure? 2nd, is 2' more tolerable for the AV-O's than the O-3's, or does it not really matter? 3rd, is this distance as important for surrounds as it is for front L&R placement? I'm thinking about having AV-O's in the rear and O-3's for up front. Also, will the AV-O's be able to hang with the OB-5's? Will the O-3's have the same speaker to wall requirements as the OB-5's? Lastly, how doest the sound of the O-3's compare to that of the OB-5's (since they are more similar... though not really)? That's it .

[Danny Richie]

Danny, any idea what benefits or difficulties might arise if you tried to use a cylinder instead of a box for the cabinet? 

I don't see any benefits but it would present many challenges.

I'm concerned about placement. 1st, when you talk about 3' from the wall, are you talking about the tweeter, or the rear of the enclosure?

It isn't an exact science. The more treated the walls are the closer they can be without adverse effects. Ideally you want to perceive a reflection as a delayed arrival and not mixed in with the on axis response.

2nd, is 2' more tolerable for the AV-O's than the O-3's, or does it not really matter?

It won't matter for the most part, but the O-3 does allow for some adjustability in the sub 200Hz range that can compensate for the low end gain.

3rd, is this distance as important for surrounds as it is for front L&R placement?

It's the same. It's is all a matter of trade offs. But rear surrounds typically handle effects, noises, sounds, ambience, and things that are meant to create or add to. So complete accuracy is less of an issue.

Also, will the AV-O's be able to hang with the OB-5's?

They'll hang.

Will the O-3's have the same speaker to wall requirements as the OB-5's?

As for placement issues? Yes, sort of. The OB-5's have a null from 200Hz to 1,500Hz or so at 90 degrees off axis. this will minimize side wall reflections throughout that range. Rear wall distances are similar.

Lastly, how doest the sound of the O-3's compare to that of the OB-5's (since they are more similar... though not really)? That's it

More similar than different. Both are very good.

[Zero]

Makes me wish I had even a basic grip on woodwork.. 

[klh]

Thanks Danny!

[Doublej]

A6M-ZERO

Don't let the lack of woodworking skills stop you. With the cabinet plans Danny provides, I think there are a number of folks that can crank out a pair of cabinets for you.

Anyone got recommendations? Group buy potential?

[Danny Richie]

Here is some measured responses for you guys.

This one shows the crossover point between the woofers and tweeter.



The top end is intentionally slightly tipped up as the speaker is meant to be listened to slightly off axis where the response will be flatter. The response also had to be tailored in a way that would give a balanced in room response. To get the flat in room response this meant a tipped up 1 meter measurement.

The adjustable output in the bottom end allowed me to balance the output for my room. My room is 23' by 17' with 9' ceilings and is well treated. Here is the 1 meter measurement after adjustment for my room.



Here is the impedance after these same adjustments.



Adding capacitance to the front woofer to increase the bass response can have an effect on the impedance that looks like this.



Taking away additional capacitance will just raise the impedance further in the 20 to 60Hz range.

Now here is one of the really cool parts. Look how clean the spectral decay is. 



Even cooler than that and a real key to why these sound so good, and fill the room so well, is the even power response in all directions.

This is the horizontal off axis response. The Red line is on axis. Orange, Yellow, Green, and Blue are 10, 20, 30, and 40 degrees off axis.



If that wasn't cool enough, check out the vertical off axis responses. These were still taken at 1 meter. The first is the Red line showing the response in line with the tweeter. Next the mic was moved up 4" (Orange line) and there was a very minimum change. Then the mic went up 4" again (Yellow line) and again the response is very smooth. Lastly is the Green line showing yet one more 4" microphone height change, and it looks great. This is only one meter away and 16" above the tweeter level. This is the same angle as being 4 meters away and 64" above the tweeter level. This would be about 8.5 feet off the floor from 4 meters away.



Awesome off axis responses huh?

[klh]

Danny... the plots are impressive, but I still have one question that wasn't answered. When you state the speakers need to be a certian distance from the wall behind them, are you measuring from the back of the enclosure or the front baffle?

[Danny Richie]

It is really hard to answer that question. It requires a subjective response. What we are really asking is how close can a speaker be to a wall before its effect on the frequency response becomes unacceptable.

A tube trap or any treatment to the walls or heavy drapes can easily sway that perception more than 6" to 10" of distance.

Speakers will need to be moved around in any room to find an optimal spot. They can always be left in one place for non-critical playback and placed somewhere else or moved out into the room for critical listening. 

[klh]

OK, thanks.

[RAW]

Those looking and emails for cabinet prices.Here you go.
Veneered in Cherry,Maple, Oak.Other veneers available .Email for quote.
O-3   $795.00 pair
AV-O $595.00 pair
Unfinished RAW MDF
O-3   $495.00 pair
AV-O $295.00 pair

Packing and Shipping will be FED EX Ground.
O-3   $175.00 pair
AV-O $145.00 pair

[klh]

Danny... somewhere along the way somone asked if you thought of using the XBL mids in the O-3 (or the other surround).  I gathered from your response that XBL woofers in general have a poor off axis response. Is that a fair assessment?

[Brucemck]

These sounded really nice at the RMAF.  Bigger and cleaner than you'd ever expect.

[Doublej]

More details please? How would you compare them to other speakes at the show?

[Milehighguy]

Just got back from the RMAF. Great show this year! Always great to see Danny and Al and Gary Dodd, really competent and talented people who don't mind talking with dummies like myself!
Anyway, in regard to the O-3, I have to say it took some open-mindedness on my part to listen to a speaker so far off-axis, but Danny kept reminding me that the sound below 2k where the woofer operates is omnidirectional.
Switching from the ob-7's was not a big difference, as Danny notes, they sound more alike than different. The sound was big and open, but with well-defined imaging. Gotta love that tweeter, very smooth and clean. uper bass was punchy and the whole presentation was open and natural, and sounded like a bigger speaker (like the ob-7). mid and low bass was a touch lean, but Danny had put foam in the ports due to some boominess in the small room, and the bass can apparently be adjusted with changes in the capacitance, so there are adjustment options. Bass of course is always room and location dependent.
I would say that these speakers, like the OB-7's, were some of the better sounding speakers at the show, and within their price range there is no doubt that the O-3's were THE biggest bargain at the show, IMHO.
 I was also VERY impressed with the new RAV-1 monitors that Danny designed and Al Wooley was showing across the hall- great clean sound and surprising punchy bass from a stand mounted speaker.

[Turk]

Congratulations, Danny...I don't believe I heard a better speaker at anywhere near the price of the O-3.  You room sounded excellent; both musical and convincing.  I was amazed at how well the design worked.  When I listened I did hear quite extended bassthat went low enough for me to do a double take, it was a bit boomy so it must have been before you stuffed the ports and rolled off the bass.  So I will guess and say that in a less difficult room many will be happy with the bass as is without a sub. Initial listening to the new interconnect you are offering may prove them to be a value equal to the O-3s in their respective function.

Plus you are great do do business with. 

[Brucemck]

These speakers had a very nice "tone" and terrific imaging.  Punchy bass (even in a less than ideal room).  A really coherent midrange.  Terrific, and very precise, imaging in all three dimensions.  They sounded much larger than they had any right to: if you didn't ask, you'd have thought the big open baffles were playing instead.  Amazing value for the money.

Danny, one question: it may have simply been the room, but, occasionally I thought I was "localizing" the tweeters which was breaking up the illusion of a single soundfield?  Seemed to happen primarily on cymbals and other largely higher frequency content, rather than anything that was either in the midrange, or, alongside/atop the midrange.  My guess is that the room was a bit too narrow, or, needed a bit of diffusion at the first reflection points?

[Danny Richie]

Danny... somewhere along the way somone asked if you thought of using the XBL mids in the O-3 (or the other surround). 

I thought about it. I don't think that the response of the XBL^ drivers will favor this alignment as it has a slope that compensates for baffle step loss. In this design we are listening in the off axis range of the woofer, so a more normal slope would be more favored for this application.

I gathered from your response that XBL woofers in general have a poor off axis response. Is that a fair assessment?

Actually the off axis response is just as good as the standard M-130.

The real kicker though is that the only M-130's that I have in stock with XBL^ motors are the samples.

it was a bit boomy so it must have been before you stuffed the ports and rolled off the bass.

Yep, you heard them before the ports got stuffed with the foam.

It wasn't an issue when the O-3's were the only speakers set up in the room, but we got to where we really didn't want to move the OB-7's (they are way to heavy to lug around) out each time to switch the speakers and we were just setting the O-3's up in front of them and just to the outside.

The problem was that the port was firing right into the outside front baffle of the OB-7's. Rather than adjusting the low end extension of the front woofer by reducing the cap value bundle, we just stuffed the ports. It gave up some low end extension but balanced them out nicely.

Danny, one question: it may have simply been the room, but, occasionally I thought I was "localizing" the tweeters which was breaking up the illusion of a single soundfield?  Seemed to happen primarily on cymbals and other largely higher frequency content, rather than anything that was either in the midrange, or, alongside/atop the midrange.  My guess is that the room was a bit too narrow, or, needed a bit of diffusion at the first reflection points?

If you check the measured responses posted here then you will see that I voiced the top end to be a little bit on the hot side so that they would be flat at closer to 20 degrees off axis. This is primarily because they will be used a lot as surround speakers and turned in a way that they are not directly aimed at the listener. We only had them turned about 5 degrees off axis in the room. This gave the top end a little more bite. They really needed to be aimed more straight into the room.

[Danny Richie]

Figured Babinga with a wipe on poly.

[Danny Richie]

New O-3 data is up on the web site now.

http://www.gr-research.com/kits/o3.shtm