AudioCircle
Industry Circles => GR Research => Topic started by: AUDFILE74 on 5 Dec 2011, 08:41 pm
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I was wondering what is the best applications for a single neo10?
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It must be used in a three way design crossing no lower than 200Hz. This can be sealed box or open baffle.
I have one of each in the works.
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okay, thanks
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It must be used in a three way design crossing no lower than 200Hz. This can be sealed box or open baffle.
I have one of each in the works.
Any teasers or eta? Thanks.
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You might want to check mine out.
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(http://www.audiocircle.com/image.php?id=54884)
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Count me as curious regarding the sealed box design. I remember reading the OB version was being put together with three OB 8" servo subs per side. Is the sealed box version being designed similarly using the servo subs sealed, 3-way full range passive design, or something else?
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Remlab, that is sweet! Tell us more....
Greg
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There's a pretty good description in the "systems" section. I will be glad to answer any other questions. One thing I didn't mention was the pre-made "sub woofer baffle" speaker bases. I got the idea after trying out end grain cutting boards. The sub woofer baffles were a much better match. The most important aspect of the design though is the modular concept. You can fine tune any one aspect of the design without having to start all over. At first It was an all peerless system with sealed mids and highs. I later decided that BG mids and highs in a dipole configuration would be the best approach. They are amazing and unique transducers.. Especially for the money!
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(http://www.audiocircle.com/image.php?id=54884)
Hi,
I have a pair of NEO10 and NEO3, so I interested to build a mid-high unit.
Can you tell me more details about your project (crossover schema and other...) ?
Thanks.
Regards.
Carlo Alberto
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I tried a small flat open baffle like that for the Neo 10 and Neo 3 combo, and the response was really bad. It needs more front wave to back wave separation or it doesn't work too well.
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Ric Schultz is going to disagree with that Danny! That's the basis for his line of OB speakers (with your OB Servo woofers).
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I tried a small flat open baffle like that for the Neo 10 and Neo 3 combo, and the response was really bad. It needs more front wave to back wave separation or it doesn't work too well.
Disappointed to hear that. I kind of figured that an OB Neo 3/10 Combo working with separate OB Servo's would be a great combo and allow for fairly easy room placement and integration.
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Ric Schultz is going to disagree with that Danny! That's the basis for his line of OB speakers (with your OB Servo woofers).
The measurements don't lie.
I started with a wider baffle and started cutting down the edges a half of an inch at a time taking measurements after each set of cuts. If you don't add the wing down one side to created more front to back separation then the response is a mess. It causes a huge peak in the 350Hz to 700Hz region followed by a dipped area at 1100Hz. With the side wing the response flats out across the board.
(http://gr-research.com/pics/test1.jpg)
(http://gr-research.com/pics/test2.jpg)
(http://gr-research.com/pics/test3.jpg)
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This is the same speaker with and without the side wing.
(http://gr-research.com/pics/best%20response.jpg)
And this was with just an 8" wing. As the wing gets deeper it shifts the peak down into the 200Hz range and lower and flattens out perfectly.
It was part of the testing and development work I was doing for a new Serenity Acoustics model.
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The measurements don't lie.
Amen. Can I get a hallelujah?!?!?!!!
:thumb:
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Hallelujah Stiffler !!
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Well Danny, that's why you can rightly be called a speaker designer/engineer, and Ric an audiophile tweaker (a quite advanced one at that!). Both valuable, but not always the same. A speaker has to be designed with solid engineering principles first; only then can tweaking begin. Some tweakers have been ahead of the engineer/designer of some products, and their tweaks actually incorporated into commercial products, both in loudspeakers and electronics. Turntables too; Brooks Berdan applied his knowledge of tuned suspensions (learned during his days of involvement in race-car design and driving) to the original Oracle turntable. He added a block of billet aluminum to the floating acrylic sub-chassis of the Oracle in just the correct location to endow it with evenly distributed mass (which the commercial product lacked). The three suspension springs (all with the same resonant frequency) were then able to keep the sub-chassis balanced as the 8-lb. platter spun---when you pushed down on the sub-chassis and let go, it bobbed up and down evenly in all four corners, just as a car with a correctly designed and built suspension does. Brooks offered his tweak as an after-market mod, and it was eventually incorporated into the turntable by Oracle. But tweaking can NOT violate the engineering (assuming the engineering is solid), only take it further. Replacing cheap components in electronics (including cross-overs, as everyone here is well aware) being a basic tweak. If the component value is kept the same, it's tweaking; if it's changed, it's engineering, is how I look at it. By that definition, Ric Shultz actually IS an engineer/designer. Measurements, as far as they go (and they go much further now than they did a few decades ago), reveal what is really happening in time and space. Tweaking, at it's best, addresses issues the designer/engineer of a product was not concerned with, or the manufactured didn't want to spend money on (often to keep a product at a certain price-point). The efforts of super-tweakers like Brooks and Ric have helped advance the State-Of-The-Art, but if their tweaks conflict with and/or contradict the designer/engineer's work (as Ric's have with yours Danny), either the engineer or the tweaker is "wrong"!
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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
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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).
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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.
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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.
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They are always in flux....just like life.
Oh so true.
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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)...?
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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.
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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... :|
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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.
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?
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.
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.
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.