SINGLE NEO-10 APPLICATIONS

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MarvinTheMartian

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Re: SINGLE NEO-10 APPLICATIONS
« Reply #20 on: 15 Jan 2015, 01:02 am »
Danny:
I never really understood how your asymmetrical "wing" loading of the open baffle line array mid-bass drivers works.

To me symmetry would be essential otherwise the short side would act as an acoustic bass short circuit.
The "path of least resistance" should determine the ultimate low frequency response.

I can envision the asymmetry redirecting a polar response peak lobe toward the long wing side.
But for the life of me I cannot figure how a single wing improved the measured frequency response.
It would be interesting to see some polar plots.

Be well soon. Shawn




     

Ric Schultz

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Re: SINGLE NEO-10 APPLICATIONS
« Reply #21 on: 15 Jan 2015, 09:04 am »
You can see a pic of my latest baffle for a single Neo 10 and single Neo 3 in my gallery.   It does not measure anything like what Danny measures on his.  Why?  Because my baffle is taller than his (18 inches), wider than his (12 inches), thicker than his (2.25 inches), rounded at the top, totally felted on the front and the back of the drivers are not loaded by flared openings.  The openings on the back are straight back from the drivers and have cotton batting and felt all around the insides of both openings and sticking out an inch or so.  So the sound coming off the back of the drivers has very limited horizontal and vertical response.....mostly fires straight back.  My speaker measures incredibly flat.  If I made a baffle like Danny's I am sure I would measure what he does.

You cannot get great sound without a super dead and thick baffle.  Same with felting....an absolute necessity.  Same with great x-over parts and wiring. However, my baffle could benefit from wings to extend its response lower.  But from 300hz on up it is super flat.

I do measure my speakers.....I know how to use a measurement system.  Not difficult.  There are many ways up the mountain.  I do not have a "basis" for my speakers.  They are always in flux....just like life.  I read as much as I can, measure and listen and then state what I know from direct experience(objectively and subjectively).  I am always learning and listen to everyone.   Danny knows a ton more about speaker crossover design (objectively) then I will ever know.  But there is much more to great sound than objective measurements (which my speaker has).

bdp24

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Re: SINGLE NEO-10 APPLICATIONS
« Reply #22 on: 15 Jan 2015, 09:51 am »
When I made stands twenty years ago for stacking two pair of Quad ESL's (a pair per side), I made them with three sheets of 3/4" MDF glued together (if I did it now I would use Green Glue), for 2-1/4" thick side panels 6" deep (with 3' long front-to-back feet/legs). I had 8' ceilings at the time, so I made them just shy of that and put spikes not only on the bottoms of the four panels, but also the tops, for spiking the tops of the stands to the ceiling. Worked great, but weighed a TON! Each Quad panel was located at the front edge of each stand, with felt attached to the inner sides of the stands, behind the Quad panels. I still have them if anybody in S. California needs stands for stacking old Quads.

Danny Richie

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Re: SINGLE NEO-10 APPLICATIONS
« Reply #23 on: 15 Jan 2015, 07:19 pm »
Danny:
I never really understood how your asymmetrical "wing" loading of the open baffle line array mid-bass drivers works.

To me symmetry would be essential otherwise the short side would act as an acoustic bass short circuit.
The "path of least resistance" should determine the ultimate low frequency response.

I can envision the asymmetry redirecting a polar response peak lobe toward the long wing side.
But for the life of me I cannot figure how a single wing improved the measured frequency response.
It would be interesting to see some polar plots.

Be well soon. Shawn

Low ranges are omni directional, and the effect is the same regardless of the position of the driver.

And the effect in the lowest ranges are the same if the baffle is wide and flat or winged on one side or both sides. But there are negative effects to making a baffle big and wide. It adds surface reflections. So you gain some later arriving reflections that disrupt the on axis response. These reflections also really hurt imaging and sound stage depth.

Even adding material to absorb reflections is an improvement. We see this in ever review of products like this: http://www.stereomojo.com/Diffraction%20Be%20Gone%20Review/DIFFRACTIONBEGONEREVIEW.htm

Now, the Neo 10 is very sensitive to surface reflections. Even a slight reflection tends to disrupt the response above 1kHz.

So what if we put a wing down both sides and get the effect of a wider baffle down low and keep a small frontal area around the driver? Sounds like a good plan on paper right? But keep in mind how high the driver plans. The shorter wavelengths that propagate within the U shape that you made sets up a cavity resonance that really messes up the response.

Have a look at this design.  http://www.audiocircle.com/index.php?topic=126112.msg1340323#msg1340323 

The woofers response looked good with the little short side wing. They don't play up high enough for any cavity resonance issues. The tweeter however, is a whole difference story. Carrying the little short wing up around the tweeter caused a big problem in the tweeters response.

The one sided wing, implemented properly, works great.

persisting1

Re: SINGLE NEO-10 APPLICATIONS
« Reply #24 on: 15 Jan 2015, 09:46 pm »
Quote
They are always in flux....just like life.

Oh so true.

NiToNi

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Re: SINGLE NEO-10 APPLICATIONS
« Reply #25 on: 20 Feb 2017, 12:17 pm »
Oldish thread, I know, but I thought I'd ask here if anyone with experience with the Neo10 (Danny, Ric, Greg etc) could tell me what the maximum SPL a single Neo10 could produce on an infinite baffle at 250-300 Hz without shrieking (i.e. within Xmax and with preserved SQ)...?

Danny Richie

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Re: SINGLE NEO-10 APPLICATIONS
« Reply #26 on: 20 Feb 2017, 04:27 pm »
Oldish thread, I know, but I thought I'd ask here if anyone with experience with the Neo10 (Danny, Ric, Greg etc) could tell me what the maximum SPL a single Neo10 could produce on an infinite baffle at 250-300 Hz without shrieking (i.e. within Xmax and with preserved SQ)...?

Maximum SPL levels really depend on distance. And with these it will also help if you filter out the lower end.

1 watt/1 meter will get you about 92db. So you can do the math from there. Double power and add 3db. Double distance and loose 6db.

NiToNi

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Re: SINGLE NEO-10 APPLICATIONS
« Reply #27 on: 20 Feb 2017, 05:30 pm »
Thanks, Danny.

No, I mean at 1m as a reference of course.

It's not so much the sensitivity as maximum SPL I'm after, mostly for proper sizing of woofer and treble and their respective amplifiers in an active 3-way. 

According to BG's datasheet, the sensitivity in free air at 250-300Hz is about 83-84db/W/m so assuming full baffle step effect at play in this measurement (given the narrow width of the driver in free air), one could assume another 5-6db on an infinite baffle (my application), best case, so let's say 89dB/W/m. For short-term power handling of 200W, that would mean peaks of up to 112dB - but only providing Xmax isn't exceeded (and yes, about -10dB at listening position 10' away). Moreover, if this is the chosen crossover frequency, where the response is down -6db (LR4), I guess I could assume 112+6=118dB in the flat portion of the passband.

Is this realistic? Sounds way beyond what could be expected from a planar driver with presumably very short Xmax and small effective Sd...  :|

Danny Richie

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Re: SINGLE NEO-10 APPLICATIONS
« Reply #28 on: 21 Feb 2017, 02:18 am »
Thanks, Danny.

No, I mean at 1m as a reference of course.

It's not so much the sensitivity as maximum SPL I'm after, mostly for proper sizing of woofer and treble and their respective amplifiers in an active 3-way. 

According to BG's datasheet, the sensitivity in free air at 250-300Hz is about 83-84db/W/m

They actually measured the driver in free air with no baffle. That is why the response looks so messed up.

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so assuming full baffle step effect at play in this measurement (given the narrow width of the driver in free air), one could assume another 5-6db on an infinite baffle (my application),


Are you making an in-wall speaker?

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best case, so let's say 89dB/W/m. For short-term power handling of 200W, that would mean peaks of up to 112dB - but only providing Xmax isn't exceeded (and yes, about -10dB at listening position 10' away).

They will easily hit the 92db level in that range. There isn't much X-Max.

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Moreover, if this is the chosen crossover frequency, where the response is down -6db (LR4), I guess I could assume 112+6=118dB in the flat portion of the passband.

You aren't going to have a limiting SPL issue with these drivers.

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Is this realistic? Sounds way beyond what could be expected from a planar driver with presumably very short Xmax and small effective Sd...  :|

If you filter off the lower ranges then you can play them pretty loud with no problems.