Foam Core Board Speaker Enclosures?

[GM]

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

[xrk971]

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.

[BP1Fanatic]

Originally Posted by GM

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

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.

[Cal Weldon]

Originally Posted by ravener

not sure if there isn't enough 'buffer' power from the amp

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.

[ravener]

Originally Posted by Cal Weldon

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.

[xrk971]

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.

[ravener]

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.

[zayne742]

Originally Posted by xrk971

I am settling to see which I want to pursue in wood now.

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.

[xrk971]

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

[xrk971]

Originally Posted by ravener

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.

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.