At the moment I'm using a B&C DE250 on an RCF H100 horn from 3,5kHz on up on my open baffle setup.
I also have some Air Motion Transformers and some Dipole planars I frequently put on them.
Out of the three options the B&C RCF combo has by far the best dynamics which also improves the bass of the system quite a bit (yes, no typo)
However, the other two options sound more natural, they have better top-end resolution and have a different presentation which is a bit more relaxed. It is not that the The B&C RCF combo sound aggressive or too forward, it's more the lack of top-end resolution that makes most of the difference. Since this is already a four-way system I don't want tot turn it into a five-way system by adding another super-tweeter. Besides, in my experience with super-tweeters in the past is that they add something nice but have a trade-off in image stability.
The option I'm currently looking at is to either try the Faital Pro STH-100 with the Faital PRO HF10AK or HF108R or go for a better dipole tweeter like a Mundorf AMT, both math the off-axis response of my wideband midrange pretty good.
I have tried the big ESS AMT's but the magnet structure forms a pretty bad-sounding waveguide and I have never been able to integrate them into the system properly.
Has anyone compared the B&C DE250 in either RCF-H100 or Faital STH-100 to the Faital HF10AK or HF108R? Both Faital drivers might have a better top-end resolution in theory but I would like an opinion from first hand. I have read the HF10AK is supposed to have more "air" but I wonder if this is really more resolution or just the rising frequency response. Frequency response shaping is also easy enough on the DE250 but that does not improve its resolution. I'm not much interested in the response towards the lower end since I cross them at 3,5kHz and won't go any lower anyway. Most of the discussions about compression drivers seem to be about how comfortably low they can go, I'm more interested in how comfortably high they can go.
Anyone?
I also have some Air Motion Transformers and some Dipole planars I frequently put on them.
Out of the three options the B&C RCF combo has by far the best dynamics which also improves the bass of the system quite a bit (yes, no typo)
However, the other two options sound more natural, they have better top-end resolution and have a different presentation which is a bit more relaxed. It is not that the The B&C RCF combo sound aggressive or too forward, it's more the lack of top-end resolution that makes most of the difference. Since this is already a four-way system I don't want tot turn it into a five-way system by adding another super-tweeter. Besides, in my experience with super-tweeters in the past is that they add something nice but have a trade-off in image stability.
The option I'm currently looking at is to either try the Faital Pro STH-100 with the Faital PRO HF10AK or HF108R or go for a better dipole tweeter like a Mundorf AMT, both math the off-axis response of my wideband midrange pretty good.
I have tried the big ESS AMT's but the magnet structure forms a pretty bad-sounding waveguide and I have never been able to integrate them into the system properly.
Has anyone compared the B&C DE250 in either RCF-H100 or Faital STH-100 to the Faital HF10AK or HF108R? Both Faital drivers might have a better top-end resolution in theory but I would like an opinion from first hand. I have read the HF10AK is supposed to have more "air" but I wonder if this is really more resolution or just the rising frequency response. Frequency response shaping is also easy enough on the DE250 but that does not improve its resolution. I'm not much interested in the response towards the lower end since I cross them at 3,5kHz and won't go any lower anyway. Most of the discussions about compression drivers seem to be about how comfortably low they can go, I'm more interested in how comfortably high they can go.
Anyone?
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Yeah the HF10AK has relatively high top output and some resonance there seen on measurements and impedance plot. Also it has kind of ragged frequency response overall and I'm not sure if it is good without some notch filters. I'm having DSP system so it is not a problem and the sound is fine. I have no other drivers to compare to so can't tell the absolute quality. I would perhaps choose the newer HF108 just by its smoother frequency response, which tells tale of better design, its 10 years younger after all. I have no idea if either sound better or not but I suspect that if both were EQ:d the same the 108 would sound more natural perhaps, lack of resonances. Perhaps with some waveguides and passive crossover the HF10AK would sound better or fun or some other adjective 🙂 I'm happy with these but will try 108 or some other model sometime in the future to compare whats the fuzz.
I'm currently using the HF108R CD with the STH100 horn with active DSP crossover. Although I like the soundcharacter of that combo, but the top-end resolution is not comparable to the best home hi-fi drivers IMO. It lacks lightness or airiness, like it sounds from behind a curtain and that's how all CD+horn combos sounded to me that I heard until now in home environment. Yeah, it's a powerful sound, but it's dull and sometimes boring (harsh in a worse case) on the long run.
I used a 18Sound ND1090 (Ti diaphragm) CD + XT120 horn and that was harsh to me, but it's one of the best 1" compression driver according to the measurements.
I used a 18Sound ND1090 (Ti diaphragm) CD + XT120 horn and that was harsh to me, but it's one of the best 1" compression driver according to the measurements.
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You have probably tried boosting the top with EQ? Sometimes the sparkle and all can be the resonances, too nasty sounds nasty, too little perhaps too boring, just enough for our age of hair cells probably sounds best?
I've done fair bit recording as hobby and have learned that all microphones that sound airy, especially the cheap ones, do so primarily due to resonances and eventually the sound is kind of poo and very fatiguing. The better mics sound boring at first but in context of a song and at mixing stage are far easier to get very good results in comparison. The bright ones attract the inexperienced to buy them, a lure. Thus, no bright sounding mics or tweeters for me, got enough of those already 🙂 Mileage might vary.
Luckily the drivers are quite easy to swap out, buy few, see which one seems better, stick with that. Use good waveguide, perhaps try few different ones, PA market stuff isn't that expensive. Remember to tune the system accordingly, don't throw better driver/waveguide away just because it was falsely judged in sub optimal setting. DSP, woofer box and freestanding waveguide on top is rather quick test bed.
I've done fair bit recording as hobby and have learned that all microphones that sound airy, especially the cheap ones, do so primarily due to resonances and eventually the sound is kind of poo and very fatiguing. The better mics sound boring at first but in context of a song and at mixing stage are far easier to get very good results in comparison. The bright ones attract the inexperienced to buy them, a lure. Thus, no bright sounding mics or tweeters for me, got enough of those already 🙂 Mileage might vary.
Luckily the drivers are quite easy to swap out, buy few, see which one seems better, stick with that. Use good waveguide, perhaps try few different ones, PA market stuff isn't that expensive. Remember to tune the system accordingly, don't throw better driver/waveguide away just because it was falsely judged in sub optimal setting. DSP, woofer box and freestanding waveguide on top is rather quick test bed.
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Yeah, maybe you are right tmuikku, and the slightly boring sound is the more honest one to the recording, but we don't know because we cannot know what's on the recording, because we playback with our speakers and not those speakers (and room + electronics) with which the recording are mixed or mastered.
Yes, I can EQ the response with the DSP to whatever I want, but that not helped the lack of air. With top-end rise, the sound became more forced.
Anyway, it's interesting that you mentioned the resonances, because the CD-s usually have resonances in their top octave, but still sounds dull, and other drivers that don't have resonances in thier top octave can sound airy. At least, that's how I experienced.
Yes, I can EQ the response with the DSP to whatever I want, but that not helped the lack of air. With top-end rise, the sound became more forced.
Anyway, it's interesting that you mentioned the resonances, because the CD-s usually have resonances in their top octave, but still sounds dull, and other drivers that don't have resonances in thier top octave can sound airy. At least, that's how I experienced.
Might be so. Also the waveguide affects heavily. Looking measurments from audioexpress for example shows that the 108 variety drop quite quickly around ~20kHz whereas some domes play past 40kHz. Even if this wasn't heard it might still add to impression. I havent studied it too much but perhaps the waveguide just cuts it off.
One should perhaps experiment with a good ATH generated waveguide paying special attention to the HF. Perhaps try wider dispersion as well, direct radiating dome has wide polar response up high whereas any waveguide would have narrower. Perhaps this also adds to airiness.
Have you tried without waveguide?
One should perhaps experiment with a good ATH generated waveguide paying special attention to the HF. Perhaps try wider dispersion as well, direct radiating dome has wide polar response up high whereas any waveguide would have narrower. Perhaps this also adds to airiness.
Have you tried without waveguide?
I tried without waveguide, but it was a really quick test, maybe I will try a bit longer just out of curiosity.
Yes curiosity is fun 🙂 did a quick try moment ago but of course the level drops drastically and don't have time to tune the DSP now 😀
Spent one more thought on it and yes the compression driver construct by definition makes acoustic low pass filter so it is not possible to have as much extension as without. One could use dome tweeter on a waveguide however, this could be a quick try as well, tape one up on the waveguide if you have one laying around.
Well, by checking out the few alternatives one learns the best what works and what doesn't. Perhaps it has to be the AMT or ribbon to get the effect and no way around.
Perhaps you have your ears still in good shape and able to hear low pass ~20kHz 🙂
Spent one more thought on it and yes the compression driver construct by definition makes acoustic low pass filter so it is not possible to have as much extension as without. One could use dome tweeter on a waveguide however, this could be a quick try as well, tape one up on the waveguide if you have one laying around.
Well, by checking out the few alternatives one learns the best what works and what doesn't. Perhaps it has to be the AMT or ribbon to get the effect and no way around.
Perhaps you have your ears still in good shape and able to hear low pass ~20kHz 🙂
I use dsp myself as well but allthough I can get the on-axis and to a certain extend the off-axis the same for all three tweeters the compression driver has the least resolution. It does sound more like a dome tweeter on top. That's why I wonder if the so called "air" from the HF10AK i really resolution or just elevated output level. That are two different things.
No, resolution is not a matter of resonance. I have been listening to my AMTs for more than 15 years without a moment of listening fatigue. Most soft dome tweeters I have heard have top end resolution that is mostly due to dome breakup and that is highly fatiguing. The Compression driver horn combo is much more dynamic though, wish it had the same resolution as the AMT. I have tried bigger AMT but they lack top-end resolution as well and have one big compromise I can't live wih, almost zero vertical dispersion. I have abandoned the big ess and the Beyma AMT, and the Raal ribbon for exactly that reason, couldn't live with them.
Have you tried smaller than 1" throat drivers, there seem to be some available? Your crossover is quite high and suitable for the smaller variety. Logic here is that perhaps cavity within the driver is smaller and low pass higher up. I'm not exactly knowing what resolution is and quessing it is the low pass it could very well be something else.
Have you checked out Gunness temporal EQ stuff? Papers and videos explaining it vailable in Fulcrum Audio site. There are several issues that he addresses in loudspeakers with the Temporal EQ and one is about clearing up top octave of compression drivers. From top of my memory due to phaseplug entrances and cavity between the membrane and phase plug max half of sound goes into slot and exists and rest stays within the cavity until max half of it exist at the next slot. For the very short wavelengths this makes "smear". By FIR filter, the temporal EQ, this can be counteracted at least some. Perhaps the solution for resolution is here.
Have you checked out Gunness temporal EQ stuff? Papers and videos explaining it vailable in Fulcrum Audio site. There are several issues that he addresses in loudspeakers with the Temporal EQ and one is about clearing up top octave of compression drivers. From top of my memory due to phaseplug entrances and cavity between the membrane and phase plug max half of sound goes into slot and exists and rest stays within the cavity until max half of it exist at the next slot. For the very short wavelengths this makes "smear". By FIR filter, the temporal EQ, this can be counteracted at least some. Perhaps the solution for resolution is here.
Yes, that conforms my experience a bit as well. Although the DE250 is the best compression driver I have tested so far and it sounds quite good it just lacks something on top that other tweeters provide. I guess using it to 8kHz with a supertweeter on top would make a nice combo. I have some Elac 4pi supertweeters lying around, wanted to try them but unfortunatly my dsp is 'only' 4-way. Might try it in another setup some day.
Still would be interesting to know if someone compared the HF10AK directly to others after shaping it to the same frequency response. Does the HF10AK's really have more top-end resolution then or is it just because of it's rising response out of the box that it sounds just louder on top? Would e nice to know befre spending a couple of hundred euros' just to find this out within five minutes myself.
Oh boy, the HF108R + STH100 is a damn good combo. Whenever I think it could be better, I’m surprised at how good it really is. It may not be perfect (but pretty close to it IMHO), but what is it?
Sjef, I posted some graphs of HF10AK on another thread if you are interested. https://www.diyaudio.com/community/threads/best-compression-drivers-today-2022.382609/post-7035056
Do you have measurements on this combo somewhere? I'm considering it for a project, active 2-2.5k+.
I have posted some measurements of a small wood horn with the 18sound NSD1095N driver in these other threads:
18sound NSD1095N thread
Best Compression Driver 2022
18sound NSD1095N thread
Best Compression Driver 2022
There's something wonky happening with it. The Z curve and THD spike up in the 3.5-4k region.
Yes, I have some, but I can do more if you (or someone else) want.
Faital pro HF108R + STH100 on-axis response, the dark yellow is the raw response with freestanding horn (I use this way), the bright yellow is with a passive attenuation circuit (8,2 Ohm resistor in series and a 0,1 mH coil to the ground "sine-cap" filter) to reduce the noise, green is the DSP corrected to LR4 2kHz target:
Harmonic distortion at 1m 90dB in the complete loudspeaker, crossed at 2kHz LR4 to a 8" midrange driver, strong 2nd harmonic domination and very low higher order harmonic distortions in the whole region of the CD+horn, (there is a strong room mode in the 100-200Hz region, but that's the bass driver anyway):
