My CD collection was used to set the media player's EQ shape that sounded most tonally balanced overall to me at my normal listening SPL regardless of which CD is played. I compared it to the JB one only because it is fairly wide BW, decently recorded and to get the bottom half of the music low enough to play 'nice' in what is admittedly a very substandard system to probably most of those on a DIY speaker forum, the upper half had way too much BSC in effect.
The youtube clip is a bit 'bright' with a 'one note' mid-bass thump compared to the JB CD, so relatively speaking, quite the opposite to your clip, which implies either not enough pipe damping and/or a lot of room EQ and/or having the recording mic in one.
Again, too much of an apples n' oranges comparison to be of much use other than to show me it's a viable design same as most others clips I've compared. If I didn't know better, I'd conclude that the majority, or at least the younger folks, like all their music to sound like a DJ mix or action movie soundtrack.
Regardless, thanks for the effort/sharing as something useful can be gleaned from all info. 🙂
GM
The youtube clip is a bit 'bright' with a 'one note' mid-bass thump compared to the JB CD, so relatively speaking, quite the opposite to your clip, which implies either not enough pipe damping and/or a lot of room EQ and/or having the recording mic in one.
Again, too much of an apples n' oranges comparison to be of much use other than to show me it's a viable design same as most others clips I've compared. If I didn't know better, I'd conclude that the majority, or at least the younger folks, like all their music to sound like a DJ mix or action movie soundtrack.
Regardless, thanks for the effort/sharing as something useful can be gleaned from all info. 🙂
GM
Probably can use more stuffing in the main pipe. I still have that hump in the FR at 200 Hz that I am trying to reduce.
I'm a 43 year old basshead for life (2-15's in an 01 f150 supercrew), but I do appreciate tonal quality over volume quantity. That's the reason why I changed my T-TQWT from firing into the corner to firing 180* into the opposite direction in January 2012. The tonal balance is so much better. I troll this thread to get ideas on how I want to upgrade the main, center, and surround speakers to keep up with the sub.
I think I remember you running this from a headphone amp. If so it's the former. You can check but seeing how much cone movement you have with it begins to distort.
To be frank, there isn't much cone movement when it distorts, but it's very obvious that it's struggling when there are too much things going on.
Will see if I can hook it up to my Megaworks 550, 70W should be a plenty.
Yeah, 70 watts ought to do the trick. 😉 probably a solid 3 is all you need, the heaphone amp is probably 500 mw. Looking forward to photos of your completed Fibonacci horn.
Yea, 70W RMS of power is pretty damn good, there are no distortion what-so-ever, even when the driver is supposed to be rated at 4W(I'm probably overloading them)
Only downside is, there is NO bass, the internal DSP of the Megaworks 550 actually filters the bass frequencies over to the sub...
and that my construction is not sturdy enough to actually hold the power being output by the driver, entire foam enclosure is rattling like a lose radiator grill.
the FiiO E11 outputs 180mW @ 32ohms, which means with my load at 4ohms, it should be supplying a max of 1.44W
pardon the crappy photos, lazy to put in the batteries for the flashgun.
Only downside is, there is NO bass, the internal DSP of the Megaworks 550 actually filters the bass frequencies over to the sub...
and that my construction is not sturdy enough to actually hold the power being output by the driver, entire foam enclosure is rattling like a lose radiator grill.
the FiiO E11 outputs 180mW @ 32ohms, which means with my load at 4ohms, it should be supplying a max of 1.44W
pardon the crappy photos, lazy to put in the batteries for the flashgun.
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Out of w-w-w-wood!? This changes everything, I am not sure we can hang out with you anymore.
All joking aside, who knew foamcore would be so versitle.
Zayne,
Lol, yeah wood, gasp. Well, at least for the facers on the Cornu and still foam on the inside. So yeah, only stepping partly to the dark side😉 One of these days when I have a real workshop with a table saw and router, I am going to go hog wild.
X
Lol, yeah wood, gasp. Well, at least for the facers on the Cornu and still foam on the inside. So yeah, only stepping partly to the dark side😉 One of these days when I have a real workshop with a table saw and router, I am going to go hog wild.
X
Ravener,
The Fibonacci looks really nice. I can only imagine that the rattle is from your rather loose screw mounts for your driver. I have not had a problem with rattling on mine even at close to max volume from a 45 W amp. Did you glue some wood on the backside for screws to grip? Some foam gasket material between the driver and the foam board facer may also reduce the rattle. One other thing, did you put any bracing on the large areas in the horn - particularly near the mouth? I try not to have any span larger thaan 3 or 4 in without at least a brace made out of foam core stock about 2 in in length x height of the space you are trying to brace. That may reduce vibration of your large areas when the frequencies hit the natural resonance of the "drum" mode of the foam core panel. You may have enough room to reach in through the mouth and hot melt glue a brace or two - it should help.
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I must confess, the bracing slipped my mind.
I do remember spamming a hell lot of glue round the screws and driver to make sure it's tight as a nut.
The rattling is actually coming from the mouth of the horn, particularly the external edge of the curve.
Nah, I'm not going to bother putting a brace in, this prototype is going to be scrapped and I'm going to make a new pair once the festivities is over - I'll be jobless by then(my company couldn't afford to keep me as production is low) - and have plenty of time on my hands to carefully craft things out.
Will take your advice into practice, i'm thinking of narrowing the width of the horn so i can make it longer, glowglass's spiral on the cornu thread gave me some inspiration to work on.
I do remember spamming a hell lot of glue round the screws and driver to make sure it's tight as a nut.
The rattling is actually coming from the mouth of the horn, particularly the external edge of the curve.
Nah, I'm not going to bother putting a brace in, this prototype is going to be scrapped and I'm going to make a new pair once the festivities is over - I'll be jobless by then(my company couldn't afford to keep me as production is low) - and have plenty of time on my hands to carefully craft things out.
Will take your advice into practice, i'm thinking of narrowing the width of the horn so i can make it longer, glowglass's spiral on the cornu thread gave me some inspiration to work on.
Ravener,
It's an easy 30 second job to add a brace or two right at the edge of the mouth - it will help especially since you say that is where it is rattling. No point is scrapping something if it can be easily fixed.
It's an easy 30 second job to add a brace or two right at the edge of the mouth - it will help especially since you say that is where it is rattling. No point is scrapping something if it can be easily fixed.
Well, this is my first attempt at a foam core enclosure, it's meant to be a practice attempt on how to build one, it's quite a rushed job, and the boards are quite shoddily put together I must say. I never thought to keep this one.
Hope you understand where I'm coming from.
Hope you understand where I'm coming from.
Has anybody looked at the half inch thick 2 X 4 foot acoustical tiles an experimental enclosure material? The are designed to absorb mid and higher frequencies, and can be glued with Tacky Glue or wood glue.
ravener, too bad to hear about the bass. It may be the horn length is not enough before it gets to the mouth and basically causes cancellation? Or it is more likely that there is leakage and too little bracing and the bass is being lost to resonating the panels?
KLB, that might work for the flat pieces but the whole thing about using the foam is that you can curve some panels. In the past I have used it instead of damping materials not as a panel.
KLB, that might work for the flat pieces but the whole thing about using the foam is that you can curve some panels. In the past I have used it instead of damping materials not as a panel.
Cal,
I'm guessing it's the former, the horn/spiral is a mere 17" on it's longest side. I'll be compressing the width of the horn and see if i can make more rounds in the spiral to lengthen it.
I'm guessing it's the former, the horn/spiral is a mere 17" on it's longest side. I'll be compressing the width of the horn and see if i can make more rounds in the spiral to lengthen it.
I asked this very question not too long ago 🙂 Yes, I think using it for either one of the facers or both on the Cornu might help. Horst Mueller (@hm) uses it as the actual channel wall material internal to his horns for this very reason - so that he doesn't have to apply felt damping or use stuffing. I wanted to use it because it comes in convenient 2x2 ft sizes and cuts with a utility knife. It is not cheap though when bought new. It may be a bargain (free) if you happen to find a construction site where they are upgrading interiors and throwing out stuff into the dumpster bin.
Milling a channel in the sides is a great way to ensure perfect placement and should increase the rigidity but it is more difficult and time consuming.
Instead of cutting a channel in the side panels how about just cutting out the area where the wall is supposed to go. That way you can wedge the wall in place, make sure all the joints are sealed from the outside, and can even cover up both sides with a nice clean sheet.
Awesome thread by the way. I've been out of audio stuff for a couple years now but this is making me want to get back into it! I've got some JX92s drivers waiting to be used but they've never been good candidates for small horns.
Bwrx,
I'm not sure what you mean about cutting out the are where the wall goes? You mean a slot? That's how the commercial Cornu is made with a slot on the middle separator panel. Once you make this out of foam you will see how easy it is to bend and hold by hand while the hot melt sets. Really fast and easy. Alignment is pretty good as you work in sections at a time. Welcome on board! I hope you give the jx92's try with the Cornu! 🙂