Why would a triple-sandwich baffle made of a constrained layer damping foamcore-cardboard-foamcore baffle that is 0.625 in thick and stiff as plywood, be inherently "un-serious"? Are your worried about secondary radiated sound from baffle vibration?
is there a cheap "shaker" which can rattle up pretty high ? thin plywood is extremely resonant - mount the shaker on plywood then constrained foam layer and compare the output
Get yourself an accelerometer and test your baffle while you sweep frequency into the driver. Nothing like objectively testing assumptions.
that's a good idea with the accelerometer - -
here's an old on-axis sweep of either the MCM or the Dayton 5 - have to dig up another speaker to figure out the identiy- there was no damping material whatsover in the "cabinet" - it may have been near my house wall and ground - (it was a loud sweep)
here's an old on-axis sweep of either the MCM or the Dayton 5 - have to dig up another speaker to figure out the identiy- there was no damping material whatsover in the "cabinet" - it may have been near my house wall and ground - (it was a loud sweep)
An externally hosted image should be here but it was not working when we last tested it.
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In case people didn't see it, Mark is leaving DIYAudio. I think this thread was the nail in the coffin 🙁 To bad he didn't jump on this thread and have a chat. He probably thought it was hopeless I'm thinking. I've called him out a number of times. Never did get a response other than I'm an amateur and he's an expert. I would have preferred this went another way.
Anyways, hopefully testing done on DIYAudio can yield more positive results than that in the future. I personally think testing is a good and valuable thing, so no reason why it can't be more helpful next time.
Anyways, hopefully testing done on DIYAudio can yield more positive results than that in the future. I personally think testing is a good and valuable thing, so no reason why it can't be more helpful next time.
Think seems some will hope a miracle for their favorite driver model or brand but think over if that driver get a form of better test setup settings the other drivers would benefit too ending up the same tendency as already published, so if baffle is made of foam core or wood all drivers have same environment.
Results published 3 times (3 setup settings) because of critism of setup settings, all drivers treated equal and all ended up same tendency the drivers between found in the 3 setup settings. At #1 first setup published and links is there to the other results.
Good enough all the inputs that both criticizing and approves the setup, probably will lead to xrk971 setup a more pro or close to pro environment to satisfy all, although i haven't problems make comparison the published ones.
CHN70 got exstra care and investigation before published, stuff as impedance measured and driver had a try in open baffle compared up against the test box looking for flaws in the setup environment, later a Japanese site confirmed same performance as xrk971. Quote #26 below and hope message later will be shared.
Results published 3 times (3 setup settings) because of critism of setup settings, all drivers treated equal and all ended up same tendency the drivers between found in the 3 setup settings. At #1 first setup published and links is there to the other results.
Good enough all the inputs that both criticizing and approves the setup, probably will lead to xrk971 setup a more pro or close to pro environment to satisfy all, although i haven't problems make comparison the published ones.
CHN70 got exstra care and investigation before published, stuff as impedance measured and driver had a try in open baffle compared up against the test box looking for flaws in the setup environment, later a Japanese site confirmed same performance as xrk971. Quote #26 below and hope message later will be shared.
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Smooth frequency response equals poor 'DDR'??? So in your opinion a system that is capable of reproducing the electrical input signal very closely (otherwise it wouldn't have a smooth FR) has a problem doing just that at different levels? That's just nonsense.
You are good at putting words in people's mouths.
Not at all. Just that in the case of the little VIFA i speculate that the designers heavily damped the cone specifically to reduce the DDR & flatten the FR. They knew that their primary market was TVs and that the source of the audio & amps could be quite poor.
dave
I think it was Paul Klipsch that said "A flat frequency response is boring." but maybe it wasn't him who said it at all.
As critical as we've been about the CHN70 I can't help wonder if in the right cabinet designs its respose can be a benefit. A back horn like the BIB amplifies response upwards of 500Hz+ without stuffing. Lowthers have horrid frequency response yet have many fans.
I've never heard a pair so not really sure what sonic signature they present... but the many good reviews suggest they do something right.
As critical as we've been about the CHN70 I can't help wonder if in the right cabinet designs its respose can be a benefit. A back horn like the BIB amplifies response upwards of 500Hz+ without stuffing. Lowthers have horrid frequency response yet have many fans.
I've never heard a pair so not really sure what sonic signature they present... but the many good reviews suggest they do something right.
Another risky subjective comment, specifically regarding the CHN70, which I guess I like more than Dave - certainly in spite of its flaws; it does work quite well in the FH3 - I might even say I prefer it to the FE126 in that enclosure. Of course the BLH load can do nothing to improve the top 2 octaves, which is where most of the major discrepancies with measures so far discussed would appear to reside.
edit: got a bit distracted - I've also recently briefly listened to the Vifa in a small sealed box, approx the same size as one in which I've lived with FF85WK for a couple of years now . Of course by the time I'd heard them, I'd already seen xrk's measures countless times, but I found the Vifa very "smooth" , certainly not at all offensive, but definitely lacking in the inner detail and dynamics that are something the Fostex do rather well - certainly for a small near field / computer desktop application.
edit: got a bit distracted - I've also recently briefly listened to the Vifa in a small sealed box, approx the same size as one in which I've lived with FF85WK for a couple of years now . Of course by the time I'd heard them, I'd already seen xrk's measures countless times, but I found the Vifa very "smooth" , certainly not at all offensive, but definitely lacking in the inner detail and dynamics that are something the Fostex do rather well - certainly for a small near field / computer desktop application.
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Zilla - for a given bulk, I'd expect a shorter/"fatter" blh to be more complimentary for CHN70 than a BIB which has little low midrange gain - maybe its a toss - if you're trying to boost a certain area. Its great that Mark makes a line of drivers which aren't priced crazy. An inexpensive "FAST" with CHN70 should be fun - perhaps with a Silver Flute woofer.
An externally hosted image should be here but it was not working when we last tested it.
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So far as i have seen everyone who actually has them and has posted, like them. Except XRK, and there may be some expectation bias.. he is hearing what he measured, not the 1st time i have seen that,
dave
Maybe. After we swaped in the treated ones they stayed in the main system for a couple weeks.
dave
have you tried adding an inexpensive helper tweeter to CHN70? - a round 1005 style piezo might be appropriate - if the piezo's lower bump is successfuly tamed so it will crossover high.
We haven't tried that. Like many drivers we git some to be able to have an opinion on them. Next up is to load the 2 pair into microTowers. We did add tweeters to the CHP70.2 microTowers. They have a similar shelved top end. A fellow in the US i chatted with said that removing the dustcaps on the CHP brought the top out.
dave
I just remembered, I have measurements of the CHR70 gen3. They're on my computer. It measured pretty close to the spec sheet if I remember. I'll try and post it up tonight.
https://www.madisoundspeakerstore.c...audio-chr-70-brushed-metal-cone-4-full-range/
https://www.madisoundspeakerstore.c...audio-chr-70-brushed-metal-cone-4-full-range/
so the next question would to narrow down the candidate list for such tweeters to more than just something that's on hand, but that would be commonly available / acceptable to others
I agree with Planet10, a smooth freq response can give a bad ddr.
Those flat measuring poly's usuall ysound "soggy" and un-detailed.
But I liked the morel polys (with talc mixed in), the mw-144 woofer I think.
Norman
Those flat measuring poly's usuall ysound "soggy" and un-detailed.
But I liked the morel polys (with talc mixed in), the mw-144 woofer I think.
Norman
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Brian Steele's "Frankenpiezo" using GRS 1016 elements with Goldwood 1016 horn/phase plug, appear relatively flat but am not sure how the pattern would mate with a little FR - I don't know how the GRS 1005 (round type) behave. The Goldwood round 1005 piezo have response that varies a lot so need to be sorted into usable pairs - they may peak on the bottom too like the original CTS and Motorola (?) - guess I better hook up a mic.
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