I'm looking for recommendations for tweeters that can cross at 1KHz. Planning on an MTM with dual 8" woofers that shouldn't be taken higher than 1KHz. It will be active, so steep slopes are possible and OK.
High on my consideration list is the ESS HEIL AMT...it's actually the only one on my list at the moment. What else can do this that's not a large compression driver needing a large waveguide?
Thanks in advance.
High on my consideration list is the ESS HEIL AMT...it's actually the only one on my list at the moment. What else can do this that's not a large compression driver needing a large waveguide?
Thanks in advance.
Some "tweeter" recommendations in this thread:
https://www.diyaudio.com/community/threads/10f-8424-rs225-8-fast-waw-ref-monitor.273524/
Not sure if you consider monacor wg300 "too large":
https://heissmann-acoustics.de/en/test-vifa-xd-270-f4-waveguide-wg-300/
Can be crossed over "at 1.2 kHz or even lower" according to alexander heissmann. Just keep an eye on thermal and excursion limits.
https://www.diyaudio.com/community/threads/10f-8424-rs225-8-fast-waw-ref-monitor.273524/
Not sure if you consider monacor wg300 "too large":
https://heissmann-acoustics.de/en/test-vifa-xd-270-f4-waveguide-wg-300/
Can be crossed over "at 1.2 kHz or even lower" according to alexander heissmann. Just keep an eye on thermal and excursion limits.
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I would venture to say a SS 9700 will do it. The 3806 would too if you can find them. I think they stopped making them after 40 years.
Maybe look at the 30 mm Wavcors, the Belisma 34 mm, Seas tweeters are known to go low, also. I have their H1212 running at 1400 hz no problem. Just don't crank them up to concert levels.
Even the Dayton RST28F can go to about 1200 hz.
Maybe look at the 30 mm Wavcors, the Belisma 34 mm, Seas tweeters are known to go low, also. I have their H1212 running at 1400 hz no problem. Just don't crank them up to concert levels.
Even the Dayton RST28F can go to about 1200 hz.
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So you’ll run into a significant power handling bottleneck without using a compression driver here…….and if you decide on a big AMT, there’s no space advantage over a 80/50 waveguide or so……..a dome is gonna give our way before a pair of 8” woofers ever will…….so from a design standpoint and a ‘choice’ of 8” woofers……high SPL is the only goal that would make sense
Ditch the MTM in name only and build it 2.5 way…..that gives you more options from a design standpoint and uses the bottom woofer to offset baffle step compensation……..center to center spacing isn’t as much an issue anymore……..but even the best domes without some mechanical bottom end help with some kind of waveguide will struggle…..badly.
Heil AmT is dipolar……how would you use that in a box between 2 8” woofers?
Lots of great surface mount AMTs out there that can cross low……Aurum Cantus makes a few…..best tweeter I’ve ever heard……ever.
Ditch the MTM in name only and build it 2.5 way…..that gives you more options from a design standpoint and uses the bottom woofer to offset baffle step compensation……..center to center spacing isn’t as much an issue anymore……..but even the best domes without some mechanical bottom end help with some kind of waveguide will struggle…..badly.
Heil AmT is dipolar……how would you use that in a box between 2 8” woofers?
Lots of great surface mount AMTs out there that can cross low……Aurum Cantus makes a few…..best tweeter I’ve ever heard……ever.
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I have heard this one here (was used in the winner box in german IGDH DIY contest 2022, I was part of the jury) :
https://www.hifisound.de/de/Lautspr...d-Acoustics-AM-25-Air-Motion-Transformer.html
https://www.hifisound.de/out/media/...5M5/IMVvGmWVlAtzOxWJGAts05Fe5vx/esl6YfQ==.pdf
Think this is a rebranded Aurum cantus, probably the AST2560:
http://aucantus.com/index.php?m=content&c=index&a=show&catid=15&id=54
Agree with @mayhem13, one of the best tweeters I have heard (cannot say "the best", e.g. I like my T25A same, but its different and everything is a matter of taste).
Never liked the Mundorf AMTs. Someone told me, in the past there was mostly used very thin Kapton foil for AMTs, but some time ago the supplier Dupont canceled supply and since then only thicker foil is used for most AMT which has worse performance (reminds me a bit of the current Breyllium drama...). Aurum Cantus seems to use different material?
https://www.hifisound.de/de/Lautspr...d-Acoustics-AM-25-Air-Motion-Transformer.html
https://www.hifisound.de/out/media/...5M5/IMVvGmWVlAtzOxWJGAts05Fe5vx/esl6YfQ==.pdf
Think this is a rebranded Aurum cantus, probably the AST2560:
http://aucantus.com/index.php?m=content&c=index&a=show&catid=15&id=54
Agree with @mayhem13, one of the best tweeters I have heard (cannot say "the best", e.g. I like my T25A same, but its different and everything is a matter of taste).
Never liked the Mundorf AMTs. Someone told me, in the past there was mostly used very thin Kapton foil for AMTs, but some time ago the supplier Dupont canceled supply and since then only thicker foil is used for most AMT which has worse performance (reminds me a bit of the current Breyllium drama...). Aurum Cantus seems to use different material?
Thank you for your input. Seems you would be right about the rebranded AC. That model does look impressive.
The Aurum AST2560 absolutely cannot be crossed over anywhere near 1kHz because of rising distortion starting around 2k Hz and falling response. Really, the only tweeter type driver that can be implemented successfully with a crossover point around 1k Hz is a compression driver in a good sized horn or waveguide or possibly the original Heil AMT. No dome tweeter is really going to handle that. It's nearly impossible to find a small, compact source that can do it. At least last I checked, but that was a couple of years ago.
Check into projects with the "Econowave" label for many examples of using a CD+horn. Even these mostly do not cross that low. I think you can use a very beefy 1" CD and a horn like the SEOS-12 or SEOS-15 and get away with a crossover point around 1kHz or even 950Hz just fine but the horn's pattern is breaking down by then a bit. The horn is larger than a small format tweeter and this requires that your woofers are located farther apart.
There is a way to avoid the woofer lobing problem with the MTM and that is to use a small fullrange driver as a tweeter. Then you can cross even lower, as low as 750 Hz. This really help to avoid that common issue with MTM designs and these sort of drivers have gotten better in the last 10 years. I built an MTM project with a FR as tweeter once before and I thought it was pretty successful. I used a 2" TangBand fullranger. Anything 2" to 3" can work, but the larger you go the worse the off-axis response will be above 7kHz.
Check into projects with the "Econowave" label for many examples of using a CD+horn. Even these mostly do not cross that low. I think you can use a very beefy 1" CD and a horn like the SEOS-12 or SEOS-15 and get away with a crossover point around 1kHz or even 950Hz just fine but the horn's pattern is breaking down by then a bit. The horn is larger than a small format tweeter and this requires that your woofers are located farther apart.
There is a way to avoid the woofer lobing problem with the MTM and that is to use a small fullrange driver as a tweeter. Then you can cross even lower, as low as 750 Hz. This really help to avoid that common issue with MTM designs and these sort of drivers have gotten better in the last 10 years. I built an MTM project with a FR as tweeter once before and I thought it was pretty successful. I used a 2" TangBand fullranger. Anything 2" to 3" can work, but the larger you go the worse the off-axis response will be above 7kHz.
https://www.parts-express.com/Aurum-Cantus-AST25120-Aero-Striction-Tweeter-276-446?quantity=1
The 25120 ABSOLUTELY can be crossed at 1k and is the recommended point from the manufacturer
The 25120 ABSOLUTELY can be crossed at 1k and is the recommended point from the manufacturer
If helped with some waveguide, SB26 versions can be filtered close to 1 kHz, if used at moderate SPL level. SB26 have one of the biggest Xmax at tweeters, 1.2 mm p-p.
SB25 rear chamber meta-material mod as here https://www.diyaudio.com/community/threads/unity-horn-with-metamaterial-tweeter.380104/post-6949987 can also help to get 1 kHz point.
SB25 rear chamber meta-material mod as here https://www.diyaudio.com/community/threads/unity-horn-with-metamaterial-tweeter.380104/post-6949987 can also help to get 1 kHz point.
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According to HiFi Compass if you are not aiming for very high spl: Satori TW29BNWG-4.
https://hificompass.com/en/reviews/satori-tw29bnwg-4
https://hificompass.com/en/reviews/satori-tw29bnwg-4
Hi,
I do not think it's wise to make tweeter cross over choices based on x-max stated by manufacturers. It's not clear at what conditions(THD%, or damage point?) it's measured and thus this number can be misleading.
SB26 is not a bad tweeter but according to distortion tests and personal experience it's not the best performer below 2.5-3 kHz. Scan speak classic series is better in this regard but at the same time more expensive.
Anyway, is there a particular reason not to include mid range unit and not try to squeeze the last bit of juice from drivers ?
Regards
I do not think it's wise to make tweeter cross over choices based on x-max stated by manufacturers. It's not clear at what conditions(THD%, or damage point?) it's measured and thus this number can be misleading.
SB26 is not a bad tweeter but according to distortion tests and personal experience it's not the best performer below 2.5-3 kHz. Scan speak classic series is better in this regard but at the same time more expensive.
Anyway, is there a particular reason not to include mid range unit and not try to squeeze the last bit of juice from drivers ?
Regards
My personal choice would be something like the Faital Pro HF108 compression drivers. Their exit is about 1" and yet they have a much bigger diaphragm than 1" hifi tweeters - so can go low (and yet can still go high enough without nasty breakup). At modest/home-hifi type levels they can be used without a horn, much like a 1" tweeter. Though of course all manner of waveguides can be used with them if wished.
I was warned that compression drivers can be choppy and uneven, but to me the HF108 sounds nicely smooth and yet is very dynamic and articulate. No doubt people's opinions and preferences will vary, but for me it has been quite a revelation; personally i won't go back to trying to make hifi tweeters go low, which is why I offer the suggestion for consideration.
I was warned that compression drivers can be choppy and uneven, but to me the HF108 sounds nicely smooth and yet is very dynamic and articulate. No doubt people's opinions and preferences will vary, but for me it has been quite a revelation; personally i won't go back to trying to make hifi tweeters go low, which is why I offer the suggestion for consideration.
Do you have a preference for dome vs. planar vs. any other type? Most 1" domes will struggle at 1,000 Hz, susceptible to power handing issues and distortion at lower frequencies. You can look at slightly larger domes, up to 1 1/2" coils but these may also perform less well at the upper high end over say 15,000 - 18,000 KHz. My approach in one pair was to use 1 1/8" dome Daytons from PE (Dayton Audio RST28F-4 1-1/8" Reference Series) and these have about 25-30% more surface area than a 1"dome and are very efficient (93 dB) and high power handling (80 watts) and cross these at 2,000 Hz to a domed style Dynavox midwoofer that can run 100-2,000 Hz, then a sub for the bass. I don't like personally 8" drivers handling midrange, and a higher xover allows all the vocals from one driver.