A 2" will not give you enough output, especially not if you cross it around 200 Hz. A 4" is the way to go when you cross around 2KHz on the other end and the Vifa I am using is a real bargain.
The ND28 could work. Give it a try and post measurements.
with waveguide facing up(or down), and mounted with diffusor/phase plug, I suppose it would work
right now thinking of those 'weird' coaxes
Attachments
but isn't this Pluto thing just boring?
why not trying sth really new? not thinking along any lines
I would follow tinitus' suggestions
for my part I say make it as short as possible, use coincident driver, bass or subbass in a separate enclosure, if crossed not too low You would not even need an enclosure for the main driver, simple baffle would suffice or even a bare driver - ask tinitus if do not believe me
do not angle anything forward but be prepared do equalize passively or actively for the treble loss (the most of treble energy would come through ceiling reflection)
You still can angle it forward with the use of spikes or else, if necessary
good luck!
best!
graaf
Pluto boring?
An externally hosted image should be here but it was not working when we last tested it.
Above: Pluto Clone right; "Spark" version left.
Spark has Peerless 2” full-range 830970 and Peerless 4” HDS 830870. With DSP for crossover and EQ is measures:
An externally hosted image should be here but it was not working when we last tested it.
From 2nd and 3rd harmonic plots it is clear that little woofer really does not want to go so low. For up close and personal it works great. At slightly less than arms length with head in between is like fantastic headphone. As I pull back, fantastic auditory scene. When tweeters are turned to face wall 8’-15’ away the reflected image is stunning.
This is excellent omnidirectional experiment.
Adding in woofers extends range and power handling.
DSP Pluto performance links:
Active v Passive #347
How to achieve coherence #43
How to achieve coherence #48
Tinitus' design has all classic problems of monkey coffins. It's omnidirectional characteristics are unknown.
Pluto type speaker is well defined, simple design that allows ready exploration of omnidirectional paradigm. Adding rear firing tweeter is possibility. I've run Pluto Clone with Spark back to back, with Spark woofer muted. Front wall reflections lock in stereo image.
Regards,
Andrew
i partly disagree. What output is required? Visaton FRS5X is good to 200hz in 0.7 litre sealed. 86dBWm should be ok for a listening level of around 90+dB. However, a 3inch would have more headroom.
Distortion performance used down to 200Hz is guaranteed to be wretched at any level much above background music listening levels.
Regards,
Andrew
funny that we suggest the exact opposite Pluto is omni 'directive' up to 1khz or so
and I suggest pure omni from 100hz and up
and btw, your Pluto does look great(with DSP)
Pluto is omni 'directive' up to 1khz or so
and I suggest pure omni from 100hz and up
Do please post measurement results on and off axis demonstrating this omnidirectional design's performance.
Pluto is completely omni up to 1kHz for woofer, just think about it alone pointing up, and it's diameter. If has no front, back, or sides in horizontal plane. Now think of 2" in minimal baffle. It is omni to about 2.5kHz, and shows normal directive behavior above that.
Regards
Andrew
I have a pair of Olasonic I use that way, about 50cm distance, no need for headphones. They just sound stunning but I will build a pair of Pluto soon, for fun.
Would the Visaton B200 be ok to experiment in a pipe firing up? With a dispersion cone of course.. I've got two seating in a box..
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Seeing as average speech SPL is ~60-70 dB, I wouldnt call 90dB background music.
I fully understand the point you make, but i own these little beasties, and theyre clean at desktop levels, and excursion is barely discernable. Distortion and excursion are hand in hand.
If you listen at 95dB day in day out then these arent for you, but at 'normal' (read not at ASBO levels) of <90dB, then i struggle to see an issue with THD... unless you sit 10m away from the speakers that is
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I have a pair of Olasonic I use that way, about 50cm distance, no need for headphones. They just sound stunning but I will build a pair of Pluto soon, for fun.
Would the Visaton B200 be ok to experiment in a pipe firing up? With a dispersion cone of course.. I've got two seating in a box..
In not an omni fan or expert, but the high Qts of the B200 could prove problematic, it is really an OB driver.
Visaton B200 is designed as high efficiency full range. Lightweight cone and size also makes it prone to break up, which even crossed fairly low with LR4 is still easily excited, leading to crossover and imaging problems when used in muti-way system.
When going multi-way an 8" with greater stiffness and xmax could work really well in pipe pointing up. Sufficient damping material is needed to smooth out/eliminate pipe resonance. For 8" crossing up at 750Hz. With 8" back to back tweeters or 2" full range in suitable enclosure could yield great results. I've pondered this for some time.
Regards,
Andrew
When going multi-way an 8" with greater stiffness and xmax could work really well in pipe pointing up. Sufficient damping material is needed to smooth out/eliminate pipe resonance. For 8" crossing up at 750Hz. With 8" back to back tweeters or 2" full range in suitable enclosure could yield great results. I've pondered this for some time.
Regards,
Andrew
totally agree, just the high qts is a little problematic. A 4 way omni with 4" up to 4k, 2inch up to 8k and tweeter for the rest. And a sub of course. Wouldnt that satisfy omni behavior?
With Pluto two way, and 1kHz crossover, the drivers are <1/3 wavelength apart, and virtually no lobing occurs in vertical or horizontal axis. with 4kHz cross from 4" to 2" driver acoustic centers need to be about 1" apart.
I just don't see big improvement possibilities with 4 way, and simplicity rules experimental exploration.
Regards,
Andrew
Of course, I didnt consider the driver centres. Just thinking out loud (bad habit), pity though, the 2inch could be nice with omni action to 8k ish (i would think).
Rightfully so.
And as I tried to point out, a little directivity in the highs is a good thing (no full omni required).
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