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GJALLARHORN Re-Fold ?!?! - Page 3

post #61 of 153
Not to threadjack, but is the FTW 21 suitable in a TH? I ask because they are now starting to ship and the price/performance in other alignments is pretty amazing.
post #62 of 153
I had the same question. I was told the ftw 21 does not have the motor strength to be placed in a TH.
post #63 of 153
Thread Starter 
Quote:
Originally Posted by LTD02 View Post

i haven't modeled it in hornresp, but i bet this one will work. the essense of the idea is like the gjallarhorn to have a long slow expansion for the first 80% or so of the horn, then a more rapid expansion toward the remaining 20% or so. hhmmm.... we'll see.



That looks pretty damn good there!

As I pondered the earlier design, I did wonder about the panel flapping at the driver mouth. Much better now.

Any concerns that diy_speaker_guy brought up?

"EDIT - looks like you figured out an alternative while I was typing. That does eliminate the dead space but I'd still be a bit concerned about potential 1/2 wave notches in those very long segments. But good luck, this looks like a lot of fun.
Edited by diy speaker guy "- Today at 4:17 pm


This design, provided that there are no issues as referenced above, would be a super easy build.
post #64 of 153
Thread Starter 
Quote:
Originally Posted by Ricci View Post

Couple of things...Dead space= an unoptomized design and performance left on the table. IMO

John try to eliminate the dead space by increasing the SD or volume of the horn sections in that area. You have 3 sections there should be no deadspace left. This will increase low bass sensitivity if done right. In order to do this you may need to play around with the expansion angles of those 3 sections. Sometimes you can keep all the same and other times not. You want the least amount of 180 degree turns and actually the least amount of turns period as you can get. The Gjallarhorn design is a product of fitting a horn with a specified low corner into a specified cabinet shape and size, which results in a lot of compromises. In fact I have learned so much since then that the fold of that makes me facepalm myself. Needless to say, among a bunch of other horn designs I have tucked away I have a redesigned version that is greatly improved in a lot of areas. (I am not giving it out so please don't email or pm me for it. Thanks.)

Yes, thanks for stopping in Ricci and sharing your thoughts!

This is getting exciting as the design is refined and hopefully gets closer to fruition!
post #65 of 153
As it looks now it seems that it can't be used standing up.
post #66 of 153
Thread Starter 
Quote:
Originally Posted by gpmbc View Post

As it looks now it seems that it can't be used standing up.

You could dump the mouth out upwards.
post #67 of 153
True, and I'm just looking from afar, honest.
post #68 of 153
Thread Starter 
Quote:
Originally Posted by gpmbc View Post

True, and I'm just looking from afar, honest.

Look from anywhere you want! Hopefully, the result will be a design that appeals to most where a cube won't fit. cool.gif
post #69 of 153
In my previous set up I had DTS 10s which can definitely kick out some low end. This is at least in a form factor that I could entertain if went back to tapped.
post #70 of 153
Thread Starter 
Quote:
Originally Posted by gpmbc View Post

In my previous set up I had DTS 10s which can definitely kick out some low end. This is at least in a form factor that I could entertain if went back to tapped.

That's what I am trying to get rid of as well. I would like the replacement to sit behind the couch rather than tower over it.
post #71 of 153
after monkeying around with this for a while more, it appears that the gjallarhorn plan can be migrated to more of a straightforward fold while preserving a substantially similar performance in many ways, improving in others, and simplifying the fold plan.

subject to further revision and refinement, this is where it stands currently, and all feedback is appreciated. i'll need to double check everything again, but I've already double checked several times of course.

the size of the unit is 30" high, 72" wide, 25.5" deep (or so depending on panel thickness used), but roughly 2.5' x 6' x 2'. obviously it is end firing, but as another option the mouth of the horn could be split into two pieces and that area removed from the side panel for something of a "dual side firing" option, or the mouth could just be taken out of the panel behind the driver.

'smushed' response of low profile horn (dark gray) vs. gjallerhorn (light gray):


architectural plan, bracing required (not shown):


hornresp:


calculations:


folding scheme:


response:


dual side firing configuration:
post #72 of 153
Quote:
Originally Posted by LTD02 View Post


...subject to further revision and refinement, this is where it stands currently, and all feedback is appreciated...




As drawn, S1 and S2 can't both be 300. If S1 is 300 then S2 should be 411.77. (Change S2 from manual to auto to preserve the taper and S2 changes to 411.77.)
This makes a rather large difference.
post #73 of 153
good catch. s2 stays at 300. s1 is what is different from the picture.

changing s1 in hornresp to 186 makes pretty much no difference.

here is the before and after.

post #74 of 153
Thread Starter 
Quote:
Originally Posted by LTD02 View Post

after monkeying around with this for a while more, it appears that the gjallarhorn plan can be migrated to more of a straightforward fold while preserving a substantially similar performance in many ways, improving in others, and simplifying the fold plan.

subject to further revision and refinement, this is where it stands currently, and all feedback is appreciated. i'll need to double check everything again, but I've already double checked several times of course.

the size of the unit is 30" high, 72" wide, 25.5" deep (or so depending on panel thickness used), but roughly 2.5' x 6' x 2'. obviously it is end firing, but as another option the mouth of the horn could be split into two pieces and that area removed from the side panel for something of a "dual side firing" option, or the mouth could just be taken out of the panel behind the driver.

'smushed' response of low profile horn (dark gray) vs. gjallerhorn (light gray):


architectural plan, bracing required (not shown):


Wow, that looks sweet! The response seems to be improved and with a more simple folding scheme to boot.

I prefer the end firing, but that orientation allows for variation which is a bonus allowing for additional placement options.

Nice work!

It is not so kludgey anymore!!! You may want to reconsider your naming scheme.smile.gif
post #75 of 153
"Nice work!"

thanks, but it was definitely collaborative. even the egging on to refold out the dead space and so forth. all good stuff.

"It is not so kludgey anymore!!! You may want to reconsider your naming scheme."

:-) yeah...i was think'n about that. maybe after one gets built and measured we can see if it might have a place in the gh family, but at this point, it's too early to broach that.
post #76 of 153
then again, it is also quite similar to this one: http://www.avsforum.com/t/1420594/hornsub-with-lms-r-how-to-construct/30#post_22333009

but with a flatter form factor. i don't know if that one ever got a name.
post #77 of 153
Thread Starter 
As some others have been asking, is this design something that the FTW-21 could be loaded in?
post #78 of 153
You guys are great. You refolded this in just a few days! My question is what values in the sim do I change (and by how much) if I wanted to try out skinning the cabinet from 24" wide to 20" or perhaps even slimmer with a different driver?
post #79 of 153
Thread Starter 
That's all John's handy work. Kudos to LTD!

Hopefully, with some sharing of ideas we can finalize a design that is easy to build, high in performance and perhaps even versatile with driver options too.

I can almost smell the sawdust!
post #80 of 153
does this all look right?

of course, lots of bracing is required and that is not shown in this one.

red braces denote INSIDE DIMENSIONS BETWEEN THE PANELS.

the most important is the one directly in front of the driver. all the others have a little 'play'.



EDIT: these are the revised and updated measurements. the previous version had 0.75" error in both directions, so all the measurements were a little off. these measurements have been confirmed to within 1/8" or so and depends a bit on how far away from 0.75" the actual wood used is.
Edited by LTD02 - 12/1/13 at 6:52pm
post #81 of 153
"Not to threadjack, but is the FTW 21 suitable in a TH? I ask because they are now starting to ship and the price/performance in other alignments is pretty amazing."

it may work in another horn, but definitely not in this one.

post #82 of 153
the ftw in a super big horn would be quite the destroyer.

i'm using the old ftw21 t/s specs, but my understanding is that the new driver's are similar. somebody link to them please.





you'll notice that the fold is one length of "par" that means a super simple fold. this one is 1200 liters, which puts the horn probably on the scale of 2.5 x 4.0 x 6.0 feet! or something in that ballpark. remember, it is "for the win"...not "for the second place". :-) and anyway, i'm not sure folks buying 21" drivers have size limitations on their subs. :-)
post #83 of 153
not sure it can take 4000 watts of power, but it doesn't exceed excursion limit (assuming a high pass for the very bottom end).

here is 4000 watts (smushed). excursion is 33mm in this one.

so yeah, it would make a lot of noise too!

post #84 of 153
all that said, the ftw with that giant cone, works fine in super large ported anyway, so there might not be a whole lot to be gained on the low end by going with a giant horn.
post #85 of 153
Thread Starter 
Quote:
Originally Posted by LTD02 View Post

all that said, the ftw with that giant cone, works fine in super large ported anyway, so there might not be a whole lot to be gained on the low end by going with a giant horn.

Oh well, at least we know now. Thanks for the data!
post #86 of 153
Thread Starter 
Quote:
Originally Posted by LTD02 View Post

does this all look right?

of course, lots of bracing is required and that is not shown in this one.

red braces denote INSIDE DIMENSIONS BETWEEN THE PANELS.

the most important is the one directly in front of the driver. all the others have a little 'play'.


Whoa!!!
I missed this post somehow!??!?!?!

This is awesome and is ready for dust to fly!
post #87 of 153
just be sure to brace it well. :-)
post #88 of 153
Thread Starter 
Quote:
Originally Posted by LTD02 View Post

just be sure to brace it well. :-)

Absolutely! If you are going to go the trouble and spend the cash, it had better be done right!wink.gif
post #89 of 153
Quote:
Originally Posted by jpmst3 View Post

Absolutely! If you are going to go the trouble and spend the cash, it had better be done right!wink.gif

jpmst3, you are going to build this correct? Will be awesome for sure smile.gif
post #90 of 153
Cool project! Looking forward to the results!
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