AVS › AVS Forum › Audio › DIY Speakers and Subs › Dual GJALLARHORNs!
New Posts  All Forums:Forum Nav:

Dual GJALLARHORNs!

post #1 of 517
12/7/12 at 7:32am
Thread Starter 
A trip over to RMK’s place a couple days ago got the wheels turning. Long story short, two JTR Orbit Shifters, which combined is two 18” drivers and 8kw of power, gave my quad 18’s and 16kw of power a run for their money! To be more specific, I feel his setup had greater output above 30hz, and mine had greater output from the mid 20’s on down.

The efficiency of the horn design definitely impressed me, so I started to look around. It didn’t take me long to find the GJALLARGORN on Ricci’s data-bass.com. From his measurements, just one gjallarhorn will outperform all four of my sealed 5400s from 16-40hz-ish, and obviously with far less power.

The plan is two build two of these, and re-use two of the 5400s from one of my sealed cabinets. That means I’ll still have two other sealed 5400s powered by a LG clone, which can help cover the top 60-80hz portion where the gjallarhorn may need some help. The only investment for me is the cost of the wood.

Ricci already emailed me the detailed plans, so all I have to do is find 4x8 sheets of quality Baltic birch and I’ll get started:)


UPDATE:


















































Edited by lukeamdman - Yesterday at 9:54 am
Reply
Reply

AVS Top Picks

post #2 of 517
12/7/12 at 7:43am
Hey Luke,

You can use 5x5 panels too. You may have to change some of the cut sheet layouts but that is sort of what I meant in my last email. If you have questions let me know. i have lots of pictures and cad files.
Reply
Reply
post #3 of 517
12/7/12 at 7:46am
You. Are. The. Man. smile.gif

I love the big horns!!!
Reply
Reply
post #4 of 517
12/7/12 at 7:59am
Horns FTW! Excellent choice.

SO bored of sealed. I was wondering why people had not built the GHs.

Look forward to the build smile.gif
Reply
Reply
post #5 of 517
12/7/12 at 8:09am
subscribed! This should be good.
Reply
Reply
post #6 of 517
12/7/12 at 8:25am
Awesome idea, tuned in. It is intriguing for sure.

On the face of it, more output is the allure, I get it. Josh's build is epic, period. However, fewer, higher output sources, vs. higher numbers of lesser output sources, doesn't always end up being advantageous when the acoustics of small rooms are involved.

But hell, I'd build it too! Especially having the benefit of the previous build, Josh's knowledge and hindsight.

Have fun and best of luck, this will be one to watch.
Reply
Reply
post #7 of 517
12/7/12 at 10:09am
That's gonna be potent set up! It'll be interesting to see if the 2 sealed will be enough to keep up in the 60 - 80 range.
Reply
Reply
post #8 of 517
12/7/12 at 12:54pm
Thread Starter 
I think I already know the answer, but I thought I'd throw it out there anyway.

For a 4x8 sheet of this "Arauco" plywood at Menards, it's $40.



Or, I found a supplier that has 5x5 sheets of 13-ply, void free, baltic birch for about $72. Top quality stuff that I've used before.

That Arauco any good, or "you get what you pay for" and I should use BB?
Reply
Reply
post #9 of 517
12/7/12 at 1:53pm
A google search turns up nada for the GJALLARGORN. Any details as to what it is?

It sounds interesting.
Reply
Reply
post #10 of 517
12/7/12 at 1:57pm
http://www.data-bass.com/data?page=system&id=45
Reply
Reply
post #11 of 517
12/7/12 at 2:19pm
Yup, the GJALLARHORN really pulls ahead of the DIY offerings from 16Hz - 50Hz. The XXX ported is the only one to go lower (10-12.5Hz) with greater spl.

DIY Systems List: http://www.data-bass.com/data?page=systems&type=0&mfr=8
Reply
Reply
post #12 of 517
12/7/12 at 2:42pm
Quote:
Originally Posted by robotbunny View Post

Yup, the GJALLARHORN really pulls ahead of the DIY offerings from 16Hz - 50Hz. The XXX ported is the only one to go lower (10-12.5Hz) with greater spl.
DIY Systems List: http://www.data-bass.com/data?page=systems&type=0&mfr=8

The GH is a DIY design by Ricci.
Reply
Reply
post #13 of 517
12/7/12 at 3:15pm
Actually his 4 LMS sealed drivers will do about 107 dBs and dual GH's will do 96 dBs.
Reply
Reply
post #14 of 517
12/7/12 at 3:53pm
Thread Starter 
Quote:
Originally Posted by MKtheater View Post

Actually his 4 LMS sealed drivers will do about 107 dBs and dual GH's will do 96 dBs.

You referring to 10hz?
Reply
Reply
post #15 of 517
12/7/12 at 5:35pm
Quote:
Originally Posted by Decadent_Spectre View Post

The GH is a DIY design by Ricci.

Thanks, didn't realize that, amazing. I'm catching up. smile.gif

This is going to be an awesome build, lukeamdman.
Reply
Reply
post #16 of 517
12/7/12 at 6:25pm
Quote:
Originally Posted by lukeamdman View Post

You referring to 10hz?

Yes, at 10hz, sorry, I was on my phone which seems to auto correct to the wrong text. Quad sealed LMS 5400's will get you 120 dBs at 20hz and the GH will get you 128 dBs. So we have the sealed system doing 120 hz and 107 dBs where the GH will be doing 128 and 96. I don't know but the sealed system will be much flatter lower and still have enough output for any movie. I can tell you I had dual DTS-10's which had 122 at 20hz and 96 at 10hz and now my system has 107 dBs at 10hz and 123 dBs at 20hz. The sealed system absolutely rocks my theater and I ran sine wave testing higher than ever before. Having increased 16-80hz does nothing when you already have 130 dBs capable with the sealed system. You should have run those OS on scenes with known ULF only and then compared the two as you would have had at least 9 dBs more capable output at 10hz. Systems do wow you when they have lots of 20hz and up but imagine having the whole bandwidth at the same levels.
Reply
Reply
post #17 of 517
12/7/12 at 6:25pm
This is going to be a fun build to watch. Keep the pictures coming. biggrin.gif
Reply
Reply
post #18 of 517
12/7/12 at 8:23pm
Quote:
Originally Posted by MKtheater View Post

Yes, at 10hz, sorry, I was on my phone which seems to auto correct to the wrong text. Quad sealed LMS 5400's will get you 120 dBs at 20hz and the GH will get you 128 dBs. So we have the sealed system doing 120 hz and 107 dBs where the GH will be doing 128 and 96. I don't know but the sealed system will be much flatter lower and still have enough output for any movie. I can tell you I had dual DTS-10's which had 122 at 20hz and 96 at 10hz and now my system has 107 dBs at 10hz and 123 dBs at 20hz. The sealed system absolutely rocks my theater and I ran sine wave testing higher than ever before. Having increased 16-80hz does nothing when you already have 130 dBs capable with the sealed system. You should have run those OS on scenes with known ULF only and then compared the two as you would have had at least 9 dBs more capable output at 10hz. Systems do wow you when they have lots of 20hz and up but imagine having the whole bandwidth at the same levels.

Actually I already went over all of this with Luke. He has 4 sealed LMS already which technically should be enough for anything sane. He knows what he is doing and doesn't really care a whole lot about <10Hz. Maybe the guy just likes to try stuff or maybe he really does want more headroom? Hell I don't know.

Also actually the GH will do about 97dB at 10Hz with no regard for distortion and the cone tapping the landing roughly the same as a sealed neither of which sound good driven to that point. So 2 is 103dB give or take not 96. At 12.5Hz peak output is about 107 or 108ish for a single, pretty close to dual sealed drivers. But again Luke isn't real concerned with sub 12Hz stuff. (Concrete floor Luke?) Over the 15-32Hz octave a single GH has comparable output to 4 sealed drivers while using 1/4 the power and compares well with 2 sealed drivers 40-100
Hz with half the power. Don't forget he is not going from 4 sealed to 2 GH but 2 GH + two sealed so the gains should be somewhat more than just comparing 2 to 1 as well. Who knows maybe he will do a wall of 4. eek.gif He may need to update his homeowners insurance either way
Reply
Reply
post #19 of 517
12/7/12 at 8:31pm
Hey I am all for giant horns if one wants or needs to use less power, less subs, and 12hz is the bottom. It will be very impressive nonetheless.
Reply
Reply
post #20 of 517
12/7/12 at 8:42pm
Siiiiick...

Ricci, this thing is an animal. Truly impressive. Will the dual sealed keep up in the upper bass and would the two extra lms's be better as two single sealed co-located? I suppose measurement would better dictate that...
Reply
Reply
post #21 of 517
12/7/12 at 9:22pm
so where is the cut sheet and dimensions of this bad boy? Or did I miss something on the data bass link?
Reply
Reply
post #22 of 517
12/7/12 at 9:26pm
funny you are building a pair of these, i was just contemplating doing a lilwrecker pair or a pair of these. I'll have to drop in once they are done and see how they sound- might influence my decision a bit.
Reply
Reply
post #23 of 517
12/7/12 at 10:38pm
Quote:
Originally Posted by lukeamdman View Post

I think I already know the answer, but I thought I'd throw it out there anyway.
For a 4x8 sheet of this "Arauco" plywood at Menards, it's $40.

Or, I found a supplier that has 5x5 sheets of 13-ply, void free, baltic birch for about $72. Top quality stuff that I've used before.
That Arauco any good, or "you get what you pay for" and I should use BB?



Hi lukeamdman,

you should use 13-ply BB like Ricci did smile.gif
Reply
Reply
post #24 of 517
12/8/12 at 6:57am
I agree with Zivkof. I'm not liking the voids in those pictures. Those can cause air leaks.

Storm the PDF I will give to anyone who wants it. It is about 20 mb though.
Reply
Reply
post #25 of 517
12/8/12 at 7:20am
Sick! Subscribed.
Reply
Reply
post #26 of 517
12/8/12 at 8:55am
Thread Starter 
Quote:
Originally Posted by MKtheater View Post

Yes, at 10hz, sorry, I was on my phone which seems to auto correct to the wrong text. Quad sealed LMS 5400's will get you 120 dBs at 20hz and the GH will get you 128 dBs. So we have the sealed system doing 120 hz and 107 dBs where the GH will be doing 128 and 96. I don't know but the sealed system will be much flatter lower and still have enough output for any movie. I can tell you I had dual DTS-10's which had 122 at 20hz and 96 at 10hz and now my system has 107 dBs at 10hz and 123 dBs at 20hz. The sealed system absolutely rocks my theater and I ran sine wave testing higher than ever before. Having increased 16-80hz does nothing when you already have 130 dBs capable with the sealed system. You should have run those OS on scenes with known ULF only and then compared the two as you would have had at least 9 dBs more capable output at 10hz. Systems do wow you when they have lots of 20hz and up but imagine having the whole bandwidth at the same levels.

I agree the sealed system is much flatter to 10hz, and the last time I measured I think I could hit 110db at 10hz at the LP. However, even with 110db at 10hz, the tactile feel is virtually non-existent. My room takes a huge bite out of SPL right at 13hz for some reason. See the graph below:



From 15-20hz, the "feel" is best described at violent. Even though my theater is below ground level on a concrete slab, the couch feels like it has bass shakers in it. However, 10-13hz, no audible bass, and only a VERY slight feel. Considering what it took to get that 110db at 10hz, I'd have to double my system to notnyt's level to make 10hz worth anything. Honestly, I don't feel like spending 6k more to get there!

RMK did have the blu-ray test disc, so I was able to hear ULF I had heard dozens of times before on the OS.

Quote:
Originally Posted by Ricci View Post

Actually I already went over all of this with Luke. He has 4 sealed LMS already which technically should be enough for anything sane. He knows what he is doing and doesn't really care a whole lot about <10Hz. Maybe the guy just likes to try stuff or maybe he really does want more headroom? Hell I don't know.
Also actually the GH will do about 97dB at 10Hz with no regard for distortion and the cone tapping the landing roughly the same as a sealed neither of which sound good driven to that point. So 2 is 103dB give or take not 96. At 12.5Hz peak output is about 107 or 108ish for a single, pretty close to dual sealed drivers. But again Luke isn't real concerned with sub 12Hz stuff. (Concrete floor Luke?) Over the 15-32Hz octave a single GH has comparable output to 4 sealed drivers while using 1/4 the power and compares well with 2 sealed drivers 40-100
Hz with half the power. Don't forget he is not going from 4 sealed to 2 GH but 2 GH + two sealed so the gains should be somewhat more than just comparing 2 to 1 as well. Who knows maybe he will do a wall of 4. eek.gif He may need to update his homeowners insurance either way

Correct, concrete floor. For me, the only reason for going to 15hz is that awesome tactile feel, and unfortunately, from 10-13hz, there's virtually zero.
Reply
Reply
post #27 of 517
12/8/12 at 10:05am
I have brick walls and a concrete floor now and it is much the same for me. I have to boost 10hz up quite a bit hot to get much of anything tactile out of it. It is just a night and day difference compared to my old wood floor room.
Reply
Reply
post #28 of 517
12/8/12 at 10:19am
Quote:
Originally Posted by Ricci View Post

I have brick walls and a concrete floor now and it is much the same for me. I have to boost 10hz up quite a bit hot to get much of anything tactile out of it. It is just a night and day difference compared to my old wood floor room.

Have you considered moving from your XXXs to the GHs now that you have a concrete/brick room? You already have a pair of them so could try them out in your room?

I'd love to see what a block of 8 of these could do in room biggrin.gif
Reply
Reply
post #29 of 517
12/8/12 at 12:17pm
Quote:
Originally Posted by lukeamdman View Post

I agree the sealed system is much flatter to 10hz, and the last time I measured I think I could hit 110db at 10hz at the LP. However, even with 110db at 10hz, the tactile feel is virtually non-existent. My room takes a huge bite out of SPL right at 13hz for some reason. See the graph below:

From 15-20hz, the "feel" is best described at violent. Even though my theater is below ground level on a concrete slab, the couch feels like it has bass shakers in it. However, 10-13hz, no audible bass, and only a VERY slight feel. Considering what it took to get that 110db at 10hz, I'd have to double my system to notnyt's level to make 10hz worth anything. Honestly, I don't feel like spending 6k more to get there!
RMK did have the blu-ray test disc, so I was able to hear ULF I had heard dozens of times before on the OS.
Correct, concrete floor. For me, the only reason for going to 15hz is that awesome tactile feel, and unfortunately, from 10-13hz, there's virtually zero.

I am also on a concrete slab, so I know the frustration of having very powerful subs that feel anemic from the low teens down. The best thing I did for my theater was to build a platform for my seats. It gives the bass energy something to move. Additionally, I attached a buttkicker to the platform, which allows me adjust the amount of tactile feeling I want. I don't adjust it much though because if you cross the buttkicker over around 20-25hz with an external crossover and dial it in just right, it just feels like the subs are moving the ground.
Edited by InPhase - 12/8/12 at 6:06pm
Reply
Reply
post #30 of 517
12/9/12 at 11:30am
Hey Luke, quick question for ya. How much of this "change" is due in part to your theater being on a concrete slab? We have basically the same bass systems and I can tell you for a fact that the ULF's in my room can have a pretty violent effect. Was RMK's theater also built on a concrete slab??
Reply
Reply
New Posts  All Forums:Forum Nav:
  Return Home
  Back to Forum: DIY Speakers and Subs

AVS Top Picks

AVS › AVS Forum › Audio › DIY Speakers and Subs › Dual GJALLARHORNs!