Dallas II plywood sheets cutting plans
Hi all,
My first post here, I have built a set of Dallas II, and for that created a cutting plan. It uses three easy to handle plywood sheets. Is anyone controlling the Dallas II original plans? If interested, please feel free to add these in there as well, they were very helpful with ordering the sheets and cutting them efficiently.
Hi all,
My first post here, I have built a set of Dallas II, and for that created a cutting plan. It uses three easy to handle plywood sheets. Is anyone controlling the Dallas II original plans? If interested, please feel free to add these in there as well, they were very helpful with ordering the sheets and cutting them efficiently.
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Dallas II with Edison 60
So, finally it's all finished, my self-built sound system:
1 - Audion Edison 60 ultralinear push-pull dual monoblock kit, the most complicated variation of this amplifier.
2 - Dallas II with Fostex FE206En backloaded exponential horn speakers, built by, and with the help of a retired pipe organ builder.
3 - Raspberry Pi 3b with IQAudioDAC music player (32bit/384kHz BurrBrown system), powered by Logitech Media Server (Squeezebox).
Well the lengthy wait, and hundreds of hours of research and work were well worthy. It does indeed sound incredibly good, I completely agree with the other reviewers commenting on the Edison 60 !!
Due to being around 23:00 when I powered it up first, I did not raise the volume above half (15-20 W), which with these ultra-efficient speakers is anyway very very loud.
Despite the speakers being brand new and probably not yet broken in, the musicality of the whole system was very obvious. The bass is very tight and impactfull, and very well controlled without making me feel the need for additional subwoofer drivers. I went through live Jazz albums, Metallica
, pipe organ music, etc., everything just makes me wanting to listen more.
I also played a few tracks from the Chesky reference album, well, due to the very high quality recordings, they do indeed sound shockingly life-life.
About noise: at no volume levels can I notice any noise while sitting in the listening position. With my ears close against the speakers I can hear a faint hissing, that does not change with the volume. It`s very impressive, with a 96-98dB/m backloaded horn system! I won`t bother myself with installing additional shielding inside the amp, although that was my intention actually.
I think this comes from the simplicity of the scheme: Very high quality DAC output going into monoblock tube amps, with each audio transformers directly driving one full-range speaker mounted in a horn: no preamp, no equalizing done in SW or HW, and of course no crossover circuitry.
So, finally it's all finished, my self-built sound system:
1 - Audion Edison 60 ultralinear push-pull dual monoblock kit, the most complicated variation of this amplifier.
2 - Dallas II with Fostex FE206En backloaded exponential horn speakers, built by, and with the help of a retired pipe organ builder.
3 - Raspberry Pi 3b with IQAudioDAC music player (32bit/384kHz BurrBrown system), powered by Logitech Media Server (Squeezebox).
Well the lengthy wait, and hundreds of hours of research and work were well worthy. It does indeed sound incredibly good, I completely agree with the other reviewers commenting on the Edison 60 !!
Due to being around 23:00 when I powered it up first, I did not raise the volume above half (15-20 W), which with these ultra-efficient speakers is anyway very very loud.
Despite the speakers being brand new and probably not yet broken in, the musicality of the whole system was very obvious. The bass is very tight and impactfull, and very well controlled without making me feel the need for additional subwoofer drivers. I went through live Jazz albums, Metallica
, pipe organ music, etc., everything just makes me wanting to listen more.I also played a few tracks from the Chesky reference album, well, due to the very high quality recordings, they do indeed sound shockingly life-life.
About noise: at no volume levels can I notice any noise while sitting in the listening position. With my ears close against the speakers I can hear a faint hissing, that does not change with the volume. It`s very impressive, with a 96-98dB/m backloaded horn system! I won`t bother myself with installing additional shielding inside the amp, although that was my intention actually.
I think this comes from the simplicity of the scheme: Very high quality DAC output going into monoblock tube amps, with each audio transformers directly driving one full-range speaker mounted in a horn: no preamp, no equalizing done in SW or HW, and of course no crossover circuitry.
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Haha got ya!
Was just about to ask for some FE206En break-in procedures. After playing all of Led Zeppelin's studio albums in a row, there is a definite improvement in bass clarity. The amp is already burned in, over the past 100 hours or so, so it's not that...
What do people do to accelerate the break-in process? I'm in no mood to listen to Shepard's tone for more than 10 seconds.
This being my first backloaded horn, what's the most shocking is the sound quality and presence even at very low volumes...
Was just about to ask for some FE206En break-in procedures. After playing all of Led Zeppelin's studio albums in a row, there is a definite improvement in bass clarity. The amp is already burned in, over the past 100 hours or so, so it's not that...
What do people do to accelerate the break-in process? I'm in no mood to listen to Shepard's tone for more than 10 seconds.
This being my first backloaded horn, what's the most shocking is the sound quality and presence even at very low volumes...
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Damping the Dallas II really necessary?
Fe206En 80-100 hours Break-in inside Dallas II Update:
After playing them at least 5 hours/day (and at most 17 hours) over the past two weeks, at very moderate volumes (probably never over 10 W) the speakers have, to my surprise completely disappeared, making place to a wonderfully wide soundstage. At these volume ranges, I can't notice any midrange shout. I was planning to install some felt (or other kind of damping material) behind the speaker, but now I do have to ask, is it really necessary? People trying this before me, have they kept it in the longterm?
Thanks.
Fe206En 80-100 hours Break-in inside Dallas II Update:
After playing them at least 5 hours/day (and at most 17 hours) over the past two weeks, at very moderate volumes (probably never over 10 W) the speakers have, to my surprise completely disappeared, making place to a wonderfully wide soundstage. At these volume ranges, I can't notice any midrange shout. I was planning to install some felt (or other kind of damping material) behind the speaker, but now I do have to ask, is it really necessary? People trying this before me, have they kept it in the longterm?
Thanks.
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How close to the corners or wall is it? (Sometimes that ~80Hz peak is due to an 8-foot ceiling).
Also, it might be interesting to put the mike at the mouth of the horn, to show the horn's response somewhat independent of the room. When Stereophile measures a speaker, they measure the low frequency with a close mike (to eliminate the room as much as possible), and then they splice it to the measurement that you took, at a certain low-ish frequency.
Also, it might be interesting to put the mike at the mouth of the horn, to show the horn's response somewhat independent of the room. When Stereophile measures a speaker, they measure the low frequency with a close mike (to eliminate the room as much as possible), and then they splice it to the measurement that you took, at a certain low-ish frequency.
This speaker is not close to a corner (more than 3 meters in any direction), and it's back panel is about 30 cm from a wall. The microphone was in the listening position, about 3 meters from the speaker. Thank you for the idea. I will try placing the mic inside the horn and redo the measure up to 600 Hz. The ceiling is 260cm high.
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Horn Measurements
Redone the measurements, placing the microphone in the horn. Indeed, the bass response is somehow smoothed, and a very clear set of resonances appear from about 150Hz.
I also measured the sensitivity: 98dB@500Hz. Not very precise, as it's done in a normal room, but still...
Redone the measurements, placing the microphone in the horn. Indeed, the bass response is somehow smoothed, and a very clear set of resonances appear from about 150Hz.
I also measured the sensitivity: 98dB@500Hz. Not very precise, as it's done in a normal room, but still...
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It does sound amazingly good, the best I've personally heard. I've never heard so much detail before, and the bass is truly beautiful in what I'm listening (jazz, classical, rock). The soundstage raises a bit above the speakers and is beautifully behind them. I can clearly identify individual instruments' and singers' positions....
Still, as I built everything myself (amplifier, speakers, cables and the player), the electrical engineer in me wanted some objective measurements on the amp and the speakers.
Still, as I built everything myself (amplifier, speakers, cables and the player), the electrical engineer in me wanted some objective measurements on the amp and the speakers.
Sure, here you go. The UMIK was less than 1 cm from the wizzer cone. What do you think?
BTW bottom end - the front of the speaker contributes nothing to it. For a realistic measurement, the microphone should be behind the speaker in the horn's pressure chamber.
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Hi,
Missed this earlier - very neat looking pair of speakers you got there, well done!
Well said jimbro!
Missed this earlier - very neat looking pair of speakers you got there, well done!
Well said jimbro!
Well, thanks. They're yet unfinished, and I think I'll just apply a clear urethane layer or two, and leave them in this colour. They sound better and better, and I'm using the system daily. Also. I'm sure the amp contributes a lot to the sound, with warmth and presence. I'm really glad I took the time to build it.
Here is an update picture. They're facing my listening position, and the sweet spot is rather wide (>1.5m at a distance of 4 meters), where the system exhibits amazing holographic properties, with real depth. Sometimes the sound seems to be coming from 10 meters behind the wall.
Here is an update picture. They're facing my listening position, and the sweet spot is rather wide (>1.5m at a distance of 4 meters), where the system exhibits amazing holographic properties, with real depth. Sometimes the sound seems to be coming from 10 meters behind the wall.
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