That's a cool one
On Saturday I wend to our local reuse centre to see if I could find any large woofers. We have been having very bad weather for a while now so donations have been low and couldn't find anything useful to mock up my idea. Plenty of subs but no actual woofers
Do we need yet another thread to discussion solutions?
krivium I can cause I know. Only I thought "anyones guitars with a 1/4" jack" meant electrics too.
You also know that I know semi-acoustics shouldn't go thru a fender amp but belong in a di box or a mixer.
You know that I wasn't talking about bass-guitars. So I don't know why you are spewing about those too? To waste peoples time? Get to the point!
You think too much compression is only bad for acoustic instruments. -That makes me wonder if you know anything about anything except writing walls of useless text about nothing really.
Please stop.
You also know that I know semi-acoustics shouldn't go thru a fender amp but belong in a di box or a mixer.
You know that I wasn't talking about bass-guitars. So I don't know why you are spewing about those too? To waste peoples time? Get to the point!
You think too much compression is only bad for acoustic instruments. -That makes me wonder if you know anything about anything except writing walls of useless text about nothing really.
Please stop.
@Guerilla : LOL.
You are right, I will get to the point: the kind of definitive sentence like 'electric guitar should be used that way', ' semi acoustic this way', 'compression suck', 'good music'... makes me laugh.
Creativity and being open minded about what musicians wants or do is the main lesson i got from the last 25years as a pro technician/studio engineer.
So yes i happily admit i know nothing about all this and still learn every times i'm hired.
It doesn't seems to be your case, how lucky you are to live in a world of certainties, it must be very confortable. In a way i'm jealous.
Randy,
Yes i think it would be better to open a dedicated thread.
You are right, I will get to the point: the kind of definitive sentence like 'electric guitar should be used that way', ' semi acoustic this way', 'compression suck', 'good music'... makes me laugh.
Creativity and being open minded about what musicians wants or do is the main lesson i got from the last 25years as a pro technician/studio engineer.
So yes i happily admit i know nothing about all this and still learn every times i'm hired.
It doesn't seems to be your case, how lucky you are to live in a world of certainties, it must be very confortable. In a way i'm jealous.
Randy,
Yes i think it would be better to open a dedicated thread.
They did, which then made the drivers once smooth off axis a bit wavy. But again, modestly so given the 2db scaling. That's also with the wide flat baffle/square edge of the KingRO4Y. Might be a bit smoother with a narrower/shaped edge baffle. Not going to get KEF/Genelec smooth, but in real rooms, that degree of off axis "error" might be ok at ears, depending on acoustics/distance etc. I'd like to hear a KingRO4Y at some point. Doubt KEF or Genelec will be offering any drivers soon ;-).
@krivium - I always learn something new whenever you write about the professional recording process... thank you for sharing your experience.
Coaxial means a certain geometrical condition, which yours does not meet, sorry.
Co-axial means shared or coincident axis, yours are not like that.
Coaxials are one special case of "2 way", the reverse does not hold true.
A rose is a flower but not all flowers are roses.
Not even quasi-roses 😄
That said, interesting design, bet they sound good. 👍🏻
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@krivium Lol lol. Im sorry and Im ashamed to admit my long distance murder attempt made me feel good for a long time. That's not nice at all.
I have only been wannabe technician for ~35 years, but that has been alongside being full time selfproclamed HiFi expert since i read my first issue of Audiovisen in 1984 or so, so I feel my endless pro-advises should have earned me the right to something. Again Im sorry, but I only came here to learn about coaxials ( of which ive seen hundreds in all kinds of automotive vehicles btw) -How could I have known I should read the comp... word here?
Oh. I worked in Norways National Broardcast concert halls studio for a longer period. But that was as a carpenter. They had Pioneer coaxials in boxes spread all around the back rows of the seatings. Chosen for being excellent neutral speakers?/drivers?
Im proud to announce that I for once ended up being somewhat on topic.😇
Please continue folks.
I have only been wannabe technician for ~35 years, but that has been alongside being full time selfproclamed HiFi expert since i read my first issue of Audiovisen in 1984 or so, so I feel my endless pro-advises should have earned me the right to something. Again Im sorry, but I only came here to learn about coaxials ( of which ive seen hundreds in all kinds of automotive vehicles btw) -How could I have known I should read the comp... word here?
Oh. I worked in Norways National Broardcast concert halls studio for a longer period. But that was as a carpenter. They had Pioneer coaxials in boxes spread all around the back rows of the seatings. Chosen for being excellent neutral speakers?/drivers?
Im proud to announce that I for once ended up being somewhat on topic.😇
Please continue folks.
That's fine with me and you are totally welcome to give an opinion on anything without badge of honor or earned rights. But be ready to be challenged, that's were we learn things, can exchange pov, share things... off topic is not such an issue if we learn things imho ( anyway if it goes through the borderline moderators kick in! ).
One thing about guitars and being creative ( i secretly hoped my first answer to you would trigger a discussion about it 😉 )... i suppose you know The Beatles and have already heard 'Revolution'? Peculiar guitar sound isn't it?
Straight into the EMI console ( REDD.51) and routed through another chanel as one only didn't get enough rough fuzz/distortion.
I suppose it was their own way to induce revolution into Abbey Road where nerd in white blouse imposed recording technique to be used until that time.
Technicaly speaking it is very wrong but it's the sound which they were after for the fast version of the song.
Of course they were monitored through Tannoy at Abbey Road sessions and Altec 604 at Trident ( or the inverse i can't remember...) where some sessions were performed too... we are back to coax! 😉
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I have now been playing with Coax speakers for more than a year. And they might be a bit ragged, but the gains of a point source, saves it for me 👍
I think I already made this comment, but if not, here goes:
You can fix the ragged response of the tweeter by putting it on a bridge.
Like they do in car coaxials.
If I had to hazard a guess on why hifi speakers don't do this, I imagine it's because the average audio buyer is unaware that you can mask off part of a woofer cone with nearly no negative impact. But if you're a buyer who's not aware of this, you probably look at a coax with a bridge and think "that's going to screw up the midrange response." (It doesn't.)
I can only think of a few companies that put the tweeter on a bridge; Geithan out of Germany I think? Kef may have in the 70s too.
Check out the response of this project I did here: https://www.diyaudio.com/community/threads/synergy-eggstravaganza.309095/post-5110101
You can fix the ragged response of the tweeter by putting it on a bridge.
Like they do in car coaxials.
If I had to hazard a guess on why hifi speakers don't do this, I imagine it's because the average audio buyer is unaware that you can mask off part of a woofer cone with nearly no negative impact. But if you're a buyer who's not aware of this, you probably look at a coax with a bridge and think "that's going to screw up the midrange response." (It doesn't.)
I can only think of a few companies that put the tweeter on a bridge; Geithan out of Germany I think? Kef may have in the 70s too.
Check out the response of this project I did here: https://www.diyaudio.com/community/threads/synergy-eggstravaganza.309095/post-5110101
Interesting thing to try would be to mount the tweeter on a volume -reduction phase plug that
1. seals the woofer cone at the baffle
2. is spaced Xmech away from the woofer cone on its back and sides
3. has bandpass ports for the bass, which could just be a ring-gap at the cone edge
1. seals the woofer cone at the baffle
2. is spaced Xmech away from the woofer cone on its back and sides
3. has bandpass ports for the bass, which could just be a ring-gap at the cone edge
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Yep.
JBL did this for some ceiling speakers, but I assume they didn't bother putting the design in anything else, because it looks like it shouldn't work.
The JBL design basically looked like a starfish covering the woofer cone, with the tweeter on the 'starfish' covering the cone.
JBL did this for some ceiling speakers, but I assume they didn't bother putting the design in anything else, because it looks like it shouldn't work.
The JBL design basically looked like a starfish covering the woofer cone, with the tweeter on the 'starfish' covering the cone.
Cause you get very bad reflections and the small baffle of the tweeter does a lot of influence at high frequencies. I measured 2-3 of these bridge tweeter coax and did some quick trials - always pretty bad. These are some of the better ones - still pretty rough: http://www.ase-scanspeak.de/ase-chassis.html
You would need proper dampening of the rear reflections from the membrane and a high crossover frequency where the baffle of the tweeter works.
It's amazing how much you can put in front of a midrange before it shows significant effect - who ever tried to make an acoustic high cut knows that.
But your attempt is really clever! Did you get to a real speaker with that?
And do you have a better 3D printer by now? 😉
An SB29RDNC-C000-4 in front of a PRV 5MR450-NDY-4 crossed at 3 KHz would certainly be problematic though, wouldn't it?
As I evaluated the Beyma 12cxa400-coax driver for a omni-directional project in the German DIY-hifi-forum, some simulation results on the topic.
Simulations have been made seperately for the bass-midrange driver and HF-driver/horn combinations to see, how they effect each other, i.e. (i) how does placement of the horn o fromt of the conus-membrane effect its frequency response and radiation pattern and (ii) what happens to the HF frequency response and radiation pattern when working in front of the conus membrane.
Simulations have been done in an infinite baffle - so no impact of a baffle or enclosure at that point.
The 12cxa400 geometry simulated:
The respective directivity plot on axis (to the top):
And frequency responses from 0° to 90°, 10°-steps:
This pretty much fits to the measurements of the Beyma published by Vance Dickason here, i.e. rising FR up to around 1.5kHz and a dip at around 2kHz shiting to lower frequencies with higher angles (note that measurements stop at 60° = orange line here). This dip is caused by the horn on front of the membrane. Beyma recommend crossover at 1.5kHz in their datasheet, which seem reaonable to me.
What about the HF?
DIrectivity:
Frequency resonses at 0° to 90°, 10°-steps:
Pretty much ok >1.5kHz. The dip just below 1.5kHz is caused by the round termination of the horn-mouth not mounted in a baffle (see Patricks comment to place tweeters in bridges in front of the woofer, i.e. add a small tweeter baffle).
Obviously Beyma hit the sweet spot keeping effects of HF-Horn placement in front of the woofer-midrange just over 1.5kHz and the HF-dip caused by the horn-termination just below 1.5kHz enabling crossover at 1.5kHz with minor effect of both issues on the overall charactersitics of this coax.
Simulations have been made seperately for the bass-midrange driver and HF-driver/horn combinations to see, how they effect each other, i.e. (i) how does placement of the horn o fromt of the conus-membrane effect its frequency response and radiation pattern and (ii) what happens to the HF frequency response and radiation pattern when working in front of the conus membrane.
Simulations have been done in an infinite baffle - so no impact of a baffle or enclosure at that point.
The 12cxa400 geometry simulated:
The respective directivity plot on axis (to the top):
And frequency responses from 0° to 90°, 10°-steps:
This pretty much fits to the measurements of the Beyma published by Vance Dickason here, i.e. rising FR up to around 1.5kHz and a dip at around 2kHz shiting to lower frequencies with higher angles (note that measurements stop at 60° = orange line here). This dip is caused by the horn on front of the membrane. Beyma recommend crossover at 1.5kHz in their datasheet, which seem reaonable to me.
What about the HF?
DIrectivity:
Frequency resonses at 0° to 90°, 10°-steps:
Pretty much ok >1.5kHz. The dip just below 1.5kHz is caused by the round termination of the horn-mouth not mounted in a baffle (see Patricks comment to place tweeters in bridges in front of the woofer, i.e. add a small tweeter baffle).
Obviously Beyma hit the sweet spot keeping effects of HF-Horn placement in front of the woofer-midrange just over 1.5kHz and the HF-dip caused by the horn-termination just below 1.5kHz enabling crossover at 1.5kHz with minor effect of both issues on the overall charactersitics of this coax.
I wouldn't cross it over at 3khz, that's too high
I would use a larger woofer and cross at 1800hz or so
Or if you need to use a five inch woofer for some reason, I'd use a small neo tweeter and a higher crossover point, like 2500hz
Any views on these type of designs. I've not been able to locate response charts but they sound good. I was thinking of replacing the back cans with wooden boxes in order to decrease the depth to between 4" and 6", the former depth size would be great. They are mainly designed for heights in a home theatre but I think they would work well for mains and surrounds too. Any input, suggestions and help will be appreciated.
I had started a thread on this here but found this thread after that.
https://www.diyaudio.com/community/...ack-can-to-wooden-box-with-less-depth.417045/
I had started a thread on this here but found this thread after that.
https://www.diyaudio.com/community/...ack-can-to-wooden-box-with-less-depth.417045/
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I am not a fan of coaxes mounted on bridges or posts, it’s impossible to prevent tweeter radiation from reflecting backwards off the cone.