I can not help it, those big open baffles are always an eyesore. I know that it's hard to make it look pleasing. So I was thinking, another option would be to make bass baffle like that weird scandinavian Gradient Helsinki 1.5, facing sideways, and have only mids/tweet on front facing open baffle.
Anybody knows how those two woofers in Gradient are wired? Seems to me like those speakers are made as mirror pair, one woofer facing left, one right. Am I right?
Anybody knows how those two woofers in Gradient are wired? Seems to me like those speakers are made as mirror pair, one woofer facing left, one right. Am I right?
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For bass frequencies, it doesn't matter which direction the woofer is facing. Gradient Helsinki 1.5 loudspeaker Measurements | Stereophile.com
Since it's a cardioid from 250hz+, it would have to be relatively narrow unless a large waveguide was used for directivity instead. It appears they're using a passive resistive enclosure for the mid, so it would have to either be narrow or small in size for midrange frequencies.
First order electrical believe it or not. Tweet is down 6dB at 14k and 12dB at 7k where it meets the FU10. Works well with both drivers.
pics in background on 4th pic..
Nice.. are those stand mount speakers in 4th pic in background open baffle too?
Nice.. are those stand mount speakers in 4th pic in background open baffle too?
Yes. Just a bamboo cutting board bolted into the top of a speaker stand. Used as surrounds for a while. I've since turned the system 90deg and will change the design to add a Neo3 and build them into the rear wall I think.
Greg
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I know this is supposed to be a thread about pics only, but for dipole bass it does matter which way the woofer faces.
The dipole null to the sides is the theoretical explanation for the advantage of dipole bass.
It's easy enough to see in action if you have a separate bass section. You can rotate them and measure the drop-off from when they face you versus when they are perpendicular.
This isn't apparent really low, but I'm not sure dipoles should be used really low anyway.
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An externally hosted image should be here but it was not working when we last tested it.
An externally hosted image should be here but it was not working when we last tested it.
An externally hosted image should be here but it was not working when we last tested it.
Here is my last build – DSP controlled active 4 way system. These speakers were built to satisfy all my audiophilic needs without sacrificing anything of following: strong bass down to 30hz, fast mid/upper bass, authoritative yet clean, open and rich sounding midrange and very detailed and natural upper midrange and treble without any coloration or sharpness.
Each loudspeaker consists of 3 modules – U-frame bass, midbass in minimal baffle and midrange-tweeter baffle on top of them. To lessen unwanted bass vibrations, modules are decoupled from each other. I have hanged the midrange-tweeter baffle so that it doesn’t vibrate at all, at least it can’t be felt by touch even on high SPL.
Each speaker driver is driven at frequencies where it performs best, keeping overall distortion low, frequency response flat, transition response fast and dispersion wide yet controlled. Special attention deserves double waveguides made by David Pellegrene, which made my tweeters shine even more.
Crossover (JRiver Media Center inbuilt DSP): 48db@120hz, 500hz, 1800hz
Drivers: Eminence Deltalite II 2515 (below 120hz), Eighteensound 12NMB420 (120-500hz), Tang Band W8-1772 (500-1800hz), Aurum Cantus AST2560 (from 1,8khz)
Enclosure materials: plywood, rubber sheets, wool felt
Dimensions: width 48cm, depth 38cm, height 123cm
Building thread with photos (in Latvian): here
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Really good looking speakers with the covers, I've always thought about doing that to dipoles to make them less ugly
My only suggestion for improvement is that you would likely reduce distortion by a lot if you inverted one of the H-frame drivers.
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The whole thing is overlaid by some pop-up advertising. Can't see a thing.
Best Regards,
TerryO
Hi Darkheart,
Nice look ! You in the North have the sense of aesthetic.
Could you say please why the choice of the Eighteen Sound in these band in relation to others similar speakers ? And why the Aurum cantus with a very low Xo at 1800 hz : see elswhere in fact this driver can't go so low without distorsion and is better around 2.5 to 3 k hz xo.
No high pass in the low end for the Delta II ? What is the natural slope rolf off here ?
regards
Eldam
Nice look ! You in the North have the sense of aesthetic.
Could you say please why the choice of the Eighteen Sound in these band in relation to others similar speakers ? And why the Aurum cantus with a very low Xo at 1800 hz : see elswhere in fact this driver can't go so low without distorsion and is better around 2.5 to 3 k hz xo.
No high pass in the low end for the Delta II ? What is the natural slope rolf off here ?
regards
Eldam
I don't believe there would be any noticeable difference - these drivers have very low distortion down to 30hz and 2nd order distortion is about as low as 3rd.
Rubberbands are not so easy to work with, if you want baffles hanging in specific height (close enough to bottom modules, but not touching them).
Decoupling between 2 lower modules is done by only 5mm thick rubber feet. Yes, there are some vibrations, but they don't distort overall sound much. The most benefit I get by decoupling the upper baffle.
You can close that window if it pops out or you can see all those photos here: Armands Kon?us - draugiem.lv
12NMB420 has outstanding Bl/Mms ratio for 12" driver, very low inductance and acceptable Qts for equalisation.
AST2560 could be crossed even lower and 2nd order crossover (I use 8th orrder), if put in a waveguide. You can look at distortion measurements in Dave's album: https://plus.google.com/photos/101632266659473725850/albums/5976006511071021745?banner=pwa
In my room bass rolls of naturally at about 30hz (where it is still flat) and is -6db at 26hz where it falls very steeply. I am using 48db high pass at 30hz for driver protection.
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