[sfdoddsy]

I accidentally bought four BG Neo10s the other day, so I guess I better do something with them.

The first thing that came to mind was a thin vertical OB arrangement in perspex with a Neo3 at the top and a pair of AE Speakers IB12s in Nelson Pass's slot loaded configuration at the bottom end. Like this sketch:


The thinking was to jump on the bandwagon of trying for dipole action as high as possible.

However, when I ran some simulations with Edge I got considerably better results with having the Neo10s horizontal, either as one big square or as MTMs.

Any thoughts whether this is worth trying, or should I continue with what I had planned based on the rule that first thoughts are always the best?

[jimdgoulding]

Not clear, here.  Are you saying that the illustration was bested by something else?  What must that look like I'd be interested to know.  Bested how?  Cheers.

[Rudolf]

I accidentally bought four BG Neo10s the other day, so I guess I better do something with them.

That's a sort of accident I could enjoy. 

However, when I ran some simulations with Edge I got considerably better results with having the Neo10s horizontal, either as one big square or as MTMs.

If Edge would show you how crazy a horizontal Neo10 beams, you would not ask for opinions.

Rudolf

[JohnR]

However, when I ran some simulations with Edge I got considerably better results with having the Neo10s horizontal, either as one big square or as MTMs.

Steve, I'm curious. What size did you use for the driver, and what do you mean by "better results" - the on axis smoothness? I might try a few sims to see too.

[scorpion]

I suppose given the circumstances you could go for one 45 degrees and one 135 degrees, or one 90 degrees and one 180 degrees fixing in the tweeter,
or just a plain vertical MTM arrangement with shrinked plastic witdh if you think constant directivity is your utmost goal.

And just don't forget the 300 Hz stereo bass requirement to meet up with the panels 

/Erling

[sfdoddsy]

Steve, I'm curious. What size did you use for the driver, and what do you mean by "better results" - the on axis smoothness? I might try a few sims to see too.

Hey John. I've attached a couple for you. Basically the horizontal or square sims are a lot smoother. The vertical ones can be improved by changing the mic position.









Rudolf,

That was the first thing that crossed my mind, then I recalled  some approval for Studiotech's build when he was thinking of a horizontal MTM arrangement.

[Jim Griffin]

Have a look at Danny Richie's 2012 RMAF creation for Serenity Acoustics at:

 http://www.audiocircle.com/index.php?topic=109918.0

Along about post #28 are photos of a horizontal Neo 10 system.  Four Neo 10s with a single Neo 3 between each pair of Neo 10s all above a dual woofer system.

http://gr-research.com/pics/s77.jpg

[Rudolf]

Rudolf,
That was the first thing that crossed my mind, then I recalled  some approval for Studiotech's build when he was thinking of a horizontal MTM arrangement.

If I remember correctly, Studiotech did it in the first place to fight a highly asymmetric room situation. Would be interesting to hear, if he would approve it as a general solution now too.

Rudolf

[JohnR]

Hey John. I've attached a couple for you. Basically the horizontal or square sims are a lot smoother. The vertical ones can be improved by changing the mic position.

Thanks Steve, interesting baffle ideas. I ran through a few scenarios to better understand. First changing the length of a 125mm wide driver to 200, 300, 400, 500 and 600mm. Baffle 300x1200, mic and driver center at 850mm:



Then different baffle widths, with a 125mmx400mm driver mounted vertically with baffle widths of 200, 300, 400 and 500 mm:



The same driver, but mounted horizontally, with baffle widths of 300, 400, 500 and 600mm:



Then with two 125x250mm drivers mounted vertically, mic in the middle, on-axis at 2m distance and then at 30 degrees off axis (mic moved to the right 1m, distance changed to 1.7m):



As above but with horizontal driver orientation:



So:

It seems that the main reason for the high frequency dropoff with the vertical orientation is the effective length of the combined driver. For some reason, it becomes noticeable above about 400mm length. Stacking e.g. four horizontal drivers gives the same effect.

Increasing the width of the baffle improves low-end response but past a certain point a null starts to show up above the dipole peak.

The big difference between the vertical and horizontal orientation is the off-axis response: while the horizontal drivers show a smoother on-axis response than the vertical drivers, the off-axis response drops off much faster.

[sfdoddsy]

Thanks for those John. I'd forgotten how to overlay on Edge. It's been a while.

Rudolf,

I also have an asymmetric listening position, with the left speaker 900mm from the side wall and the right over 6 metres. I also slouch when listening so vertical dispersion is important.

I was pondering the Legacy Whisper mid setup, which is designed to reduce horizontal dispersion.

[scorpion]

Of course in many ways these are interesting simulations, not perhaps revealing very much about the real thing.
First I would be certain that I had bass playing up to 300 Hz unobstructed so as to produce the stereo I wanted in that range.
Then I would go along prototyping with cheap simplex or MDF and try the various outlay options and listen and if I had the means measure performance.
I don't think it would be much more difficult than that. First choice to me beforehand would be the standard MTM layout.

/Erling

[studiotech]

If I remember correctly, Studiotech did it in the first place to fight a highly asymmetric room situation. Would be interesting to hear, if he would approve it as a general solution now too.

Rudolf

You are correct.  I tried the horizontal layout to combat a poor room layout.  I did not like the result and stayed with the more traditional layout, which is no longer an issue because I flipped my room around and now have both baffles 7ft+ from the side walls.  The change in sound is dramatic.  I went from soundstage and spacially average sound to actually getting better sound than at the studio for the first time ever  I need far less treatments than before and am getting far better results.  Got those things far away from the walls AND closer to you.

Greg

[studiotech]

Thanks for those John. I'd forgotten how to overlay on Edge. It's been a while.

Rudolf,

I also have an asymmetric listening position, with the left speaker 900mm from the side wall and the right over 6 metres. I also slouch when listening so vertical dispersion is important.

I was pondering the Legacy Whisper mid setup, which is designed to reduce horizontal dispersion.

I was initially very inspired by the Legacy designs.  The Whisper and Helix both sound excellent, but I've only ever heard them in large rooms well out away from the walls, so Bills theory of design to narrow horizontal radiation is still not proven to my ears.  My original set-up had the left speaker placed right up against the wall and the right speaker placed about 5 feet from the wall.  Even with 4" of bonded logic from floor to ceiling at the first reflection points, my center image was vague and shifted with frequency range.  It was much better than without anything, but getting them out from the walls worked miracles.  Now my stage is solid, precise and stable.  And very three dimensional in both depth and height.

Greg

[sfdoddsy]

Of course in many ways these are interesting simulations, not perhaps revealing very much about the real thing.
First I would be certain that I had bass playing up to 300 Hz unobstructed so as to produce the stereo I wanted in that range.
Then I would go along prototyping with cheap simplex or MDF and try the various outlay options and listen and if I had the means measure performance.
I don't think it would be much more difficult than that. First choice to me beforehand would be the standard MTM layout.

/Erling

That's what I'll be doing. I have a test baffle design that will allow me mount the drivers either vertically or horizontally just by sliding them around, so I'll give them a listen and a measure.

[JohnR]

I'll be interested to read how you go, Steve. I've generally found the sims to be reasonably accurate, in predicting the main features of the response if not the exact thing.

[sfdoddsy]

Thanks John. For some reason I'm going through a burst of speaker upgradeitis. I've had Maggie 1.7s, Nakamichi Dragons and Apogee Stages at home to compare with my bastard Orions in an attempt to simplify everything. I'd prefer not to have a full three way active system and not to be constantly diagnosing glitches with the DCX, an errant cable, or whatever.

Alas, the current version of my speakers sounded better than the above. Then SL came out with the LX521 and that's a fairly easy build so I'll give that a bash. Then I drunkenly bought the Neo10s and have been trying to work out whether a narrow baffle using them to my design would be any better than SL's crafted LX521.

The answer is probably not.

Hence pondering trying to create controlled directivity speaker by deliberately restricting the horizontal.

At least I can probably flip the Neo10s for what I paid here in Oz if it doesn't work out.

Of course what I should be doing is try something completely different from the Orions rather than an incremental improvement.

Which is why I'm also eying a StigErik style line array using the RD75 or RD50. As well as presumably sounding 'different' this would actually simplify my system a lot. One amp for the  array, a MiniDSP for EQ and crossover, and a Crown Cdi to power and Eq the bass.

Fun times.

Not surprisingly my girlfriend (who loves the sound and looks of my Orions) thinks I'm nuts.

[Davey]

Not surprisingly my girlfriend (who loves the sound and looks of my Orions) thinks I'm nuts.

You are!  Just like all the rest of us. 

Dave.

[studiotech]

Steve, have you considered something like the Digmodas I use?  It greatly simplifies wiring and amount of gear.  They sound really very good.  We've done comparisons now with the Powersoft units and an outboard BSS Omnidrive and Bryston amps.  No loss compared to the Byston set-up and killed the Powersoft.

Greg

[sfdoddsy]

Yes, I've considered the Digmoda gear a while back. From memory cost was an issue and I couldn't work out where to put it on my sperakers.

I will reinvestigate.

[Rocket_Ronny]

Greg:

Are you able to get enough punch on the low end of those neo 10s running open baffle? I forget the crossover point, 200 or so? Sorry if already discussed.

Rocket_Ronny