Hi Shure and Alex M!
Shure,
I tried reverse then positive tweeter polarity. In reverse polarity, the sound is balanced between bass and treble, except for the notch around 3kHz tweeter suck-out. In positive tweeter poloarity, the bass is boomier, and gives the impression of less treble. However, the issue might be more acoustic than electrical. I'll experiment with more Acoustifill, aperiodic port tuning, or rolling felt into the port hole, or elongating the port from its 68x160mm length.
I would prefer to listen in positive tweeter polarity according to D'Appolito design.
I'm comparing to 2 other floor standers I've built. In the photo, the right is a 3-way with a parallel fed Visaton 13", and series-fed SS 18WU, and 66000. The left is a 2.5-way with SS Classic 8-7-1 with a parallel fed 21W, and series-fed 18W and 98000 drivers. Both very high quality.
Thanks Alex M, yes.
Shure,
I tried reverse then positive tweeter polarity. In reverse polarity, the sound is balanced between bass and treble, except for the notch around 3kHz tweeter suck-out. In positive tweeter poloarity, the bass is boomier, and gives the impression of less treble. However, the issue might be more acoustic than electrical. I'll experiment with more Acoustifill, aperiodic port tuning, or rolling felt into the port hole, or elongating the port from its 68x160mm length.
I would prefer to listen in positive tweeter polarity according to D'Appolito design.
I'm comparing to 2 other floor standers I've built. In the photo, the right is a 3-way with a parallel fed Visaton 13", and series-fed SS 18WU, and 66000. The left is a 2.5-way with SS Classic 8-7-1 with a parallel fed 21W, and series-fed 18W and 98000 drivers. Both very high quality.
Thanks Alex M, yes.
Attachments
Shure, Please move the speaker around. I tried different locations, and room bass gain varied as much as 8dB. When placed close to corner or walls, the bass was a little boomy, obscuring some treble, muddying the midrange clarity, and imaging
I tried to stuff the port with acoustifill, boominess went away, but lost the air and reverb. I didn't like it.
Since these speakers will be placed near a wall, I then lined the side walls, top, and bottom a single layer of 30mm acoustilux, and lined the rear wall with 2 layers of 30mm acoustilux. I added 3in more acoustifill from Parts-Express on the rear wall. This reduced boominess, improved clarity, without any loss to air and imaging.
Then I began to wonder, and see what the 68x160mm port tuning is. Wow, a 68x160mm port tuning calculates to 50Hz, a very high tuning. port lengt is too short. It should be tuned in the range of 40-45Hz. This in turn would make the speaker sound boomy, muddy the mids, and decrease the overall perception of treble. I just swapped the 68x160 port with a 68x220mm tube now, and voila. The speaker is now tuned to 44Hz (down from 50Hz) and has made a huge improvement.
If you don't have a longer port, or can't fit a longer one, try rolling a slightly trapezoidal piece of felt once around the inner wall of the port as a para-aperiodic port or "stealth reflex." I tried this and it works equally well as a longer port, and helps cut more midrange coming out of the port.
Double check your crossover, caps, and resistor, and inductor values. I've had great luck with Jantzen Superior Z, Mundorf Supremes, and Mundorf Silver Oil caps.
Double check your solder connections. I've cold solder joints in the past before at the terminals.
I really hope you can be happy with this speaker.
I tried to stuff the port with acoustifill, boominess went away, but lost the air and reverb. I didn't like it.
Since these speakers will be placed near a wall, I then lined the side walls, top, and bottom a single layer of 30mm acoustilux, and lined the rear wall with 2 layers of 30mm acoustilux. I added 3in more acoustifill from Parts-Express on the rear wall. This reduced boominess, improved clarity, without any loss to air and imaging.
Then I began to wonder, and see what the 68x160mm port tuning is. Wow, a 68x160mm port tuning calculates to 50Hz, a very high tuning. port lengt is too short. It should be tuned in the range of 40-45Hz. This in turn would make the speaker sound boomy, muddy the mids, and decrease the overall perception of treble. I just swapped the 68x160 port with a 68x220mm tube now, and voila. The speaker is now tuned to 44Hz (down from 50Hz) and has made a huge improvement.
If you don't have a longer port, or can't fit a longer one, try rolling a slightly trapezoidal piece of felt once around the inner wall of the port as a para-aperiodic port or "stealth reflex." I tried this and it works equally well as a longer port, and helps cut more midrange coming out of the port.
Double check your crossover, caps, and resistor, and inductor values. I've had great luck with Jantzen Superior Z, Mundorf Supremes, and Mundorf Silver Oil caps.
Double check your solder connections. I've cold solder joints in the past before at the terminals.
I really hope you can be happy with this speaker.
As D'Appolitos, the Dappos are very nice, they have that characteristic presence factor. They give you a near field presentation from a distance. And of course, they have a narrow sweet spot in the horizontal plane. The off-axis response is not great, and the XT25, along with some of the ring radiators are down considerably @ 30-deg off axis above 10kHz.
As for comparisons, a 5.5" speaker can't compete with an Scan-Speak Classic 8" 2.5-way, or my reference 13" 3-way Scan-Speak Illuminators in terms of dynamics, FR, transients.
What surprises me most about the Dappo is its neutrality and naturalness of in conveying tone and timbre. The 15W wooofers offer excellent extension without the nasty cone break-up. I can't say that about the 18W or the 18WU woofers in the Scan-Speak line. It really shows at high volume and with string instruments. This atttribute seems to quench digital glare better than my other speakers, especially on 80s rock and opera CDs.
As for comparisons, a 5.5" speaker can't compete with an Scan-Speak Classic 8" 2.5-way, or my reference 13" 3-way Scan-Speak Illuminators in terms of dynamics, FR, transients.
What surprises me most about the Dappo is its neutrality and naturalness of in conveying tone and timbre. The 15W wooofers offer excellent extension without the nasty cone break-up. I can't say that about the 18W or the 18WU woofers in the Scan-Speak line. It really shows at high volume and with string instruments. This atttribute seems to quench digital glare better than my other speakers, especially on 80s rock and opera CDs.
Absolutely! For 80s Rock/Metal CDs, the lack of glare projecting through the Dappos is really surprising. 80s CDs are notorious for horrible A/D and overall sound is thin and harsh. The Dappos impart a tonal neutrality which makes listening to Rock/Metal more tolerable than any other speaker in my collection. The 4-order roll-off in the crossover and lack of nasty cone break-up peaks in the 3-6kHz range are the reason for this smoothness. With a high order roll-off, I don't hear any beaming with the Dappo. Even at high volume, the drivers compress in an ear-friendly way. The 15W/8530K 5.5in woofer is a gem on midrange and bass, for its size. Bear in mind too, the Janzten Superior Z Caps sound very neutral, but spacious.
I didn't have high expectations for this project, but it has been quite a surprise. I've only had to fiddle with port tuning. Whereas my reference 13in 3-way Scan-Speak Iluuminator speakers required 5 revisions of the crossover to get it right.
If you want the bottom octave, one can always add a sub. I have stereo subs cabs, employing two 32/4878T00 Scan-Speak 13in subs. Expensive, but worth it. They replaced my TC Sounds Epic 12in, which one had a popped VC - junk.
of the 80s.I spent hundreds of hours on them and tried everything that I could think of.
I guess this speakers wasn't for me, sold them yesterday.
I have 2 new projects that im working on right now, one is an exact clone of pandion 5 (should be hard to fail on that one) and the other is a "diy" kit from a big brand using Seas beryllium tweeter and seas magnesium woofer.
Where do you get the scanspeak revelator D29Xx/99007 from. I world like to buy a matched pair.
I have the orginal relevator 99000 soft dome pair. Do you have some data sheet or measurement of the customized relevator. decay Time, impedance, speaker parameters. Tell me more of the pandion 5 clone
I'd hate to see anybody give up on a speaker - too many hours, effort, money are invested.
It's difficult to attribute any adjectives to the XT25TG-04 - It's not silky, metallic, it just renders treble with flat neutrality. If you're looking for a lively sound, it's too dark due to its thicker cone compared to other ring radiators. However, compared to the XT25TG-04, the 99000 it may have the same tonal characteristics, but will project timbral quality much differently due to its wave guide, hence give you a livelier sound.
The Scan-Speak sliced paper cone was not the midrange for you. Seas, in general, has clearer midrange, but Scan-Speak has deeper bass. Seas magnesium cones are excellent, but make sure you're clear of any cone break-up frequencies in your crossover - may have to go higher order roll-off.
Beryllium tweeters have the best clarity, transparency, neutrality against a black background. In other words, they don't sound silky like textile domes, or metallic like Ti or Al domes. Be tweeeters will give you ultimate neutrality and transparency, so place the best series caps you can afford. You can make the Be domes hotter, and you're less likely to distort or make them sound harsh.
If you're looking for livelier side of neutral, I've used Mundorf Supreme and Mundorf Silver Oil caps with excellent results.
In any case, I'm working on another D'Appolito design with a pair of 6.5in SBA MW16P-8 woofers and the TW29BN Be tweeter. The voicing will be totally different than the Dappo.
It's difficult to attribute any adjectives to the XT25TG-04 - It's not silky, metallic, it just renders treble with flat neutrality. If you're looking for a lively sound, it's too dark due to its thicker cone compared to other ring radiators. However, compared to the XT25TG-04, the 99000 it may have the same tonal characteristics, but will project timbral quality much differently due to its wave guide, hence give you a livelier sound.
The Scan-Speak sliced paper cone was not the midrange for you. Seas, in general, has clearer midrange, but Scan-Speak has deeper bass. Seas magnesium cones are excellent, but make sure you're clear of any cone break-up frequencies in your crossover - may have to go higher order roll-off.
Beryllium tweeters have the best clarity, transparency, neutrality against a black background. In other words, they don't sound silky like textile domes, or metallic like Ti or Al domes. Be tweeeters will give you ultimate neutrality and transparency, so place the best series caps you can afford. You can make the Be domes hotter, and you're less likely to distort or make them sound harsh.
If you're looking for livelier side of neutral, I've used Mundorf Supreme and Mundorf Silver Oil caps with excellent results.
In any case, I'm working on another D'Appolito design with a pair of 6.5in SBA MW16P-8 woofers and the TW29BN Be tweeter. The voicing will be totally different than the Dappo.
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I wouldnt say that the XT25 renders a "flat neutrality" rather very dark or closed in, in my opinion.
I like the scan speak driver used in pandion 5, but that is the uncoated version, much more livley sound.
The seas kit is already pre assembled, its actually an upgrade kit from XTZ to upgrade their 99 series speakers, they use the Mundorf Supreme capacitors as well
Aren't you generalizing an awful lot when u say textile domes sound silky and Ti or Al domes sound metallic?
My ceramic tweeters doesn't sound hard becouse the material is, my D2905 doesn't sound soft becouse the material is.
I like the scan speak driver used in pandion 5, but that is the uncoated version, much more livley sound.
The seas kit is already pre assembled, its actually an upgrade kit from XTZ to upgrade their 99 series speakers, they use the Mundorf Supreme capacitors as well
Aren't you generalizing an awful lot when u say textile domes sound silky and Ti or Al domes sound metallic?
My ceramic tweeters doesn't sound hard becouse the material is, my D2905 doesn't sound soft becouse the material is.
Indeed I have... For every generalization, there are exceptions. For example, the 98000 Al dome, is more silky than metallic. But it's an expensive way to find out otherwise. Generalizations only give us a good start and might keep us safe from potential pitfalls and surprises had we not known about them.
For extra sparkle, you might even like the Mundorf Evo line... Don't forget to experiment with bypass caps too
For extra sparkle, you might even like the Mundorf Evo line... Don't forget to experiment with bypass caps too
I fully agree. Whether a high output impedance tube amp or a low output impedance solid state amp is used can really make a big difference.
Unfortunately Troels Gravesen doesn't use any impedance correction circuits in his speaker designs. He completely ignores the interaction of amplifier output impedance and speaker load impedance. He simply connects a speaker like the Ellam Dappo to his tube amp and that is it.
Even his solid state amp is class A with zero negative feedback. One should notice that Troels Gravesen is using all kind of exotic gear that is tuned and modified to his liking, but regular solid state amps do not exist in his world.
Perhaps everyone using a solid state amp should wire an additional 1 ohm resistor in series to the loudspeaker cable in order to get the intended sound!
I fully agree. Whether a high output impedance tube amp or a low output impedance solid state amp is used can really make a big difference.
Unfortunately Troels Gravesen doesn't use any impedance correction circuits in his speaker designs. He completely ignores the interaction of amplifier output impedance and speaker load impedance. He simply connects a speaker like the Ellam Dappo to his tube amp and that is it.
Even his solid state amp is class A with zero negative feedback. One should notice that Troels Gravesen is using all kind of exotic gear that is tuned and modified to his liking, but regular solid state amps do not exist in his world.
Perhaps everyone using a solid state amp should wire an additional 1 ohm resistor in series to the loudspeaker cable in order to get the intended sound!
I can't disagree, but at the same time he keeps the response of his speakers quite warm tonally compared with many commercial speaker designs (ProAc, for instance), which makes them arguably more solid-state friendly.
Alex
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