Not really on topic, Plutone are neither really efficient, nor cheap at all... Plutone are just intented to fill a non existing void, as so many speakers projects... Speakers as usual designed by dyiers as usual, sempiternel flawed designs based of exoctic and expensive drivers and parts, illustrated by unfair measurements as bad faith second hand car reseller arguments, it 's getting almost boring to see that, making diy worse than a supermarket!
In the end Genelec stuff is not that expensive and surely better designed!
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The kit price is based on the parts cost in The Netherlands (where I live) - nothing extra added. They include 21% dutch sales tax. If sold outside the EU they are free from this sales tax.
The peak 500-900Hz is a product of baffle step so the notch filter is necessary. He explains further in the text.
RC is not a notch filter.
All these JA-8008 measurement are too good to be true... Or i bought the wrong units?
My quick and dirty shots at 0º, 30º and 60º on a 28X42 baffle...
What's her name?
It does look awfully like this one Troels did:
http://www.troelsgravesen.dk/QUATTR...attro-8008-spl_cab_noXO_merged350-375-400.jpg
And yes, it looks like i'd never bought it. Directivity wise - now we see why there are no 60 deg off-axis measurements for tqwt or quattro - or Pluton ftm. Xover frequency is just too high for an 8" woofer. I mean, -8dB at 60deg at the xover region.
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Plutone on-axis and off-axis measurements: Red on-axis; Green 15 degrees off-axis; Purple 30 degrees off-axis; Yellow 45 degrees off-axis; Range 200Hz - 20kHz / Vertical scale 50-100dB; subdivisions 2dB's
Crossoverpoint from woofer to tweeter is at 2400Hz.
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GDO, thank you for the measurements.
Unless I'm mistaken, almost every 6"-12" I've ever measured exhibits this 600-800Hz dip.
With my Acoustic Elegance TD6M, I covered the basket posts with closed cell foam. This lessened the dip.
Until 'basket' manufacturers start 'rounding' the inside edges, this dip will occur. It's likely a reflection.
Or am I out to lunch?.
Unless I'm mistaken, almost every 6"-12" I've ever measured exhibits this 600-800Hz dip.
With my Acoustic Elegance TD6M, I covered the basket posts with closed cell foam. This lessened the dip.
Until 'basket' manufacturers start 'rounding' the inside edges, this dip will occur. It's likely a reflection.
Or am I out to lunch?.
From what i see there is about 3dB dip starting at 2.8KHz so that's why i would really like to see 60deg measurement and measurement on axis at the same graph
Individual driver rolloffs would be great just to back up the claim for 2.4KHz xover frequency.
Cheers
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A reflection would show differently under different axis. Shape is the same a 0º, 30º, 60º, so it is clear for me that this is no acoustical problem (reflection, baffle diffraction effect,...) , but a mechanical one, cone/suspension resinance.
It's true that many driver, especially paper cones, show problems like this, but in this case it's pretty ugly, especially for a masterpiece boutique driver...
But what bothers me most, is some efforts to mask the sad reality, like this one:
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Yep!
From the blog:
Zaph|Audio
The CSD is more "informative", but as nobody cares about stuff like that...
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Yes, a link from his website. The measurement is done with the driver set on a large baffle - so there is no sign of baffle effects!
In his own words: Zaph|Audio
"All response curves are with the drivers on an infinite baffle. All drivers are countersunk, and all baffle openings are chamfered in back for smooth airflow. Don't forget that in the real world, baffle step and diffraction will affect the curves. These curves are all far field, taken with a 10ms gating window. Below 600 Hz, a near field measurement is merged in for accuracy. Response curves include impedance curves at the bottom."
I bet that those 600-800Hz are baffle edge interferences, they do appear also off-axis as you can see tfom this measurement done outdoors yesterday. A6,5" woofer (coax SEAS) in 9" x 13" box. I measured also backside radiation! 180Hz is ground reflection.
In his own words: Zaph|Audio
"All response curves are with the drivers on an infinite baffle. All drivers are countersunk, and all baffle openings are chamfered in back for smooth airflow. Don't forget that in the real world, baffle step and diffraction will affect the curves. These curves are all far field, taken with a 10ms gating window. Below 600 Hz, a near field measurement is merged in for accuracy. Response curves include impedance curves at the bottom."
I bet that those 600-800Hz are baffle edge interferences, they do appear also off-axis as you can see tfom this measurement done outdoors yesterday. A6,5" woofer (coax SEAS) in 9" x 13" box. I measured also backside radiation! 180Hz is ground reflection.
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And all your deeps above 180Hz are odd multiples of 180Hz: comb filtering! What about putting a shorter time window?
Btw, Zaph says he usually merges at 600Hz. It looks like in this case he has been generous/forgiving enough to merge higher, where it hurts less...
Multiplies of edge resonances can be seen even at 4ms. Sidewalls are 6m away...
A wide baffle Orangutan has it's own problems http://www.stereophile.com/content/...-loudspeaker-measurements#tZqRvYr3Egdt6Vy3.97
A wide baffle Orangutan has it's own problems http://www.stereophile.com/content/...-loudspeaker-measurements#tZqRvYr3Egdt6Vy3.97
An externally hosted image should be here but it was not working when we last tested it.
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