Would you mind posting burst decay plot from ARTA?
Here is HF10AK in STH100, on-axis 1m. There is ~10uF cap so little bit of slope alreary at 1kHz but interested about what the top octave looks like.
Here is HF10AK in STH100, on-axis 1m. There is ~10uF cap so little bit of slope alreary at 1kHz but interested about what the top octave looks like.
Last edited:
Here it is the burst decay (some reflections in the low-end because of long gating time required):
And the cumulative spectral decay with shorter gating time:
All measurements done with the LR4 2kHz crossover.
And the cumulative spectral decay with shorter gating time:
All measurements done with the LR4 2kHz crossover.
I have Just ordered a pair of Hf10ak drivers and STH100 horns. I was in doubt between the hf10ak a d the hf108r but I got a very good deal on the hf10ak's. I will report back how they compare to the B&C DE250 on the RCF H100 horns. I am only using them from 3.5khz With 60db/oct FIR crossovers and I am mostly looking for some more detail on top without having to add a supertweeter and turn the systeem in to 5 way. I Just hope the 'sparkle' or detail of the hf10ak is not Just break-up. Nobody could tell me so I Just have to find out myself.
After playing around With the Hf10ak drivers my primarely conclusion.
With both drivers the RCF h100 sounds better than the Faital Sth100. It just sounds more organic, more open with more body, more flesh and blood and above all, the in-room power response is a better match with my midrange. It simply sounds bigger, easier, more dynamic with a more integrated sound.
More tweeking is needed to say something about the compression drivers them selves, (going to buy a other pair of h100 horns to be able to compare directly in stereo setup) but for the horns the RCF is a clear winner in my system. Not that the Sth100 is bad but I guess it might match better with a horn loaded midrange.
Listening to the hf10ak on my desktop fed with a fullrange signal with some mockup eq I would say it's real strength is in the lower treble/ higher midrange, that's where it is clearly more detailed than the de250 so I think they really deserve a much bigger horn and a supertweeter. Could be interesting for my office system (every office deserves good sound, makes work a lot more enjoyable)
With both drivers the RCF h100 sounds better than the Faital Sth100. It just sounds more organic, more open with more body, more flesh and blood and above all, the in-room power response is a better match with my midrange. It simply sounds bigger, easier, more dynamic with a more integrated sound.
More tweeking is needed to say something about the compression drivers them selves, (going to buy a other pair of h100 horns to be able to compare directly in stereo setup) but for the horns the RCF is a clear winner in my system. Not that the Sth100 is bad but I guess it might match better with a horn loaded midrange.
Listening to the hf10ak on my desktop fed with a fullrange signal with some mockup eq I would say it's real strength is in the lower treble/ higher midrange, that's where it is clearly more detailed than the de250 so I think they really deserve a much bigger horn and a supertweeter. Could be interesting for my office system (every office deserves good sound, makes work a lot more enjoyable)
Measure and EQ them alike, still different sound? I have lost my secobd h100 during years, gotta order one more to finally hear the thing in stereo 😀
Yes, eq-ed alike as far as possible With two different radiation patterns of coarse. Somehow the Sth100 sounds like it doesn't load the compression driver in the way the h100 does which makes it a little bit nevous With a hazy soundstage. The rcf horns has more guts and balls.
ah yes the horns would sound different, but the drivers on same horn, is the HF10AK still nicer than de250?
Unfortunately H100 seems to be out of stock in many places.. perhaps its time for me to get custom ones 3d printed.
Unfortunately H100 seems to be out of stock in many places.. perhaps its time for me to get custom ones 3d printed.
My hf10ak's are on the testbench right now burning in. They where quote dull and rogh straight out of the box but opened up after 4-5 hours or do. Will let them play a couple of days and will compare them 1 on 1 With the de250 on the same horns. For now my suspicion is that the added air or sparkle is no more than break-up but not sure yet. It's the lower part where the hf10ak's excel.
Yeah I think so too, but I don't have nothing to compare to.
Similar thing as with most drivers, more or less breakup and all kinds of phaseplug stuff going on past 10kHz. If one has DSP I have no reason to believe there is mucho difference what driver is used (in home, where they are not working on their limits), just takes more biquads to shape, unless you have a driver that has no issues up there, see the burst decay plots earlier in this thread and all seem to have phase plugs / diaphragms output smeared in time. Gunnes Temporal EQ should fix it, but no idea how to derive one. Cone material might have some difference in sound, Ti and plastic for example. HF10AK (and de250) has plastic diaphragm but so have many others, that are probably better mechanical and acoustic design, like 10 years newer design hf108(r) seems to be.
If one has speaker with passive crossover and perhaps certain type of horns there is much bigger difference with sound as most of "the issues" are left as is like rising top octave, not equalized to match and compared side by side other one has more sparkle etc.. Perhaps this is why HF10AK is touted, it has sparkle due to the resonance and perhaps some waveguides benefit, while others would just sound too bright / nasty. HF108(r) would probably be better sounding in any waveguide especially if EQ:d the same, not as much issues in the manufacturer graphs at least.
Anyway, perhaps HF10AK is a good one anyway, I haven't compared side by side to anything and it sounds just fine and have no plans to swap it in near future. I cut the top peaks heavily currently, -8db on 13kHz and there seems to be another nasty sound around 18k or so and cut that too some, basically EQ looking at power response, or listening window.
Similar thing as with most drivers, more or less breakup and all kinds of phaseplug stuff going on past 10kHz. If one has DSP I have no reason to believe there is mucho difference what driver is used (in home, where they are not working on their limits), just takes more biquads to shape, unless you have a driver that has no issues up there, see the burst decay plots earlier in this thread and all seem to have phase plugs / diaphragms output smeared in time. Gunnes Temporal EQ should fix it, but no idea how to derive one. Cone material might have some difference in sound, Ti and plastic for example. HF10AK (and de250) has plastic diaphragm but so have many others, that are probably better mechanical and acoustic design, like 10 years newer design hf108(r) seems to be.
If one has speaker with passive crossover and perhaps certain type of horns there is much bigger difference with sound as most of "the issues" are left as is like rising top octave, not equalized to match and compared side by side other one has more sparkle etc.. Perhaps this is why HF10AK is touted, it has sparkle due to the resonance and perhaps some waveguides benefit, while others would just sound too bright / nasty. HF108(r) would probably be better sounding in any waveguide especially if EQ:d the same, not as much issues in the manufacturer graphs at least.
Anyway, perhaps HF10AK is a good one anyway, I haven't compared side by side to anything and it sounds just fine and have no plans to swap it in near future. I cut the top peaks heavily currently, -8db on 13kHz and there seems to be another nasty sound around 18k or so and cut that too some, basically EQ looking at power response, or listening window.
Last edited:
Tried to take distortion measurement with ARTA because the other hf10ak I have had audible distortion while measuring frequency response. Never done before distortion measurements so might contain errors, but the relative results are legit I think. This is naked driver without any waveguide, mic was 1 meter away as I was measuring the whole speaker and the rig was there so.
Anyway, number 2 of my drivers as baseline, no audible distortion while doing sweeps. No idea what the SPL level was, but nevertheless, this one didn't sound distorted on low frequencies during the sweep while the other did.
the other sounding nasty measured like so
And then opening it up and repositioning diaphragm as well as tightening the back cover back again made difference but still there was slight audible buzz, not as bad, but there it was, while measuring frequency response.
Then opened it up again, there is small wiggle with the diaphragm placement, like half millimeter or so, ridiculous. Then when one drops the back cover on the assembly can still move until screws are tightened up so its pretty much hit or miss... This time better success, almost as good as the other driver so stopped here.
Thought to post this, if anyone ever drops one or opens it up, be sure to compare distortion to the other you have to find out if the diaphragm is centered / damaged. I think this one is the one I opened up several years ago but never checked if there was issues with it, I've been on single speaker mono up until now when noticed the issue. It might also been dropped at some point during the shelving years.
Distortion looks nice past 2kHz. If one is going to use it below this then it doesn't look too bad either, there seems to be almost no difference between 500-2kHz, although I'm not sure how legit the measurements are so take it as is 🙂 No quarantee about audibility other than when one shoots towards 10% it definitely was audible.
Anyway, number 2 of my drivers as baseline, no audible distortion while doing sweeps. No idea what the SPL level was, but nevertheless, this one didn't sound distorted on low frequencies during the sweep while the other did.
the other sounding nasty measured like so
And then opening it up and repositioning diaphragm as well as tightening the back cover back again made difference but still there was slight audible buzz, not as bad, but there it was, while measuring frequency response.
Then opened it up again, there is small wiggle with the diaphragm placement, like half millimeter or so, ridiculous. Then when one drops the back cover on the assembly can still move until screws are tightened up so its pretty much hit or miss... This time better success, almost as good as the other driver so stopped here.
Thought to post this, if anyone ever drops one or opens it up, be sure to compare distortion to the other you have to find out if the diaphragm is centered / damaged. I think this one is the one I opened up several years ago but never checked if there was issues with it, I've been on single speaker mono up until now when noticed the issue. It might also been dropped at some point during the shelving years.
Distortion looks nice past 2kHz. If one is going to use it below this then it doesn't look too bad either, there seems to be almost no difference between 500-2kHz, although I'm not sure how legit the measurements are so take it as is 🙂 No quarantee about audibility other than when one shoots towards 10% it definitely was audible.
Last edited:
Half an mm wiggle in diaphragm placement is truly ridiculous!
Thanks for the warning. Normally I always have a look on the inside of things whenever possible but I will skip that urge with these drivers
Thanks for the warning. Normally I always have a look on the inside of things whenever possible but I will skip that urge with these drivers
Haha yes that was partly sarcastic from me, not sure whats the standard for these kind of "self centering diaphragms". Well, anyway, felt small, difficult to get right unless by lucky. . It could be also just from tightening of the bolts, precise even tension all around.
I like the HF108 (without the R) a lot more than that HF10K to be honest, i tried both on a XT1086 horn, a quiet different horn than yours. But the treble is way more controlled and need a lot less eq to sound real good than the HF10K (I used dsp to eq). I did measure it, but as it was someone else's project, i don't have the files anymore. They were tested by audioexpress altough: https://audioxpress.com/article/test-bench-faital-pro-hf108r-compression-driver