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Dual GJALLARHORNs! - Page 17

post #481 of 758
Thread Starter 
Quote:
Originally Posted by FOH View Post

lukeamdman,
Just got up to speed on this build, very, very nice. Congrats for sure. I can stare at those cut-away/cross section images of the cabinet for hours, great job.

Thanks!
post #482 of 758
Thread Starter 
I got the other one powered up and ran some measurements with each cabinet in the exact same position in the room. The results were excellent.

The phase was completely identical at every frequency, and for SPL, the only time the lines weren't identical was a slight 2-3db bump on one around 100hz. Much better than I was expecting!

Here's the response of both using only Ricci's basic EQ recommendations. 15hz 18db BW HPF (bumped it up slightly from 14hz because I have so much room gain below 20hz), and a 60hz 18db BW LPF:



Nothing new here. Response drops like a rock at 13hz, and there's a huge crater at 50hz just like every other sub I've ever had in this room.
post #483 of 758
Quote:
Originally Posted by lukeamdman View Post

I got the other one powered up and ran some measurements with each cabinet in the exact same position in the room. The results were excellent.

The phase was completely identical at every frequency, and for SPL, the only time the lines weren't identical was a slight 2-3db bump on one around 100hz. Much better than I was expecting!

Here's the response of both using only Ricci's basic EQ recommendations. 15hz 18db BW HPF (bumped it up slightly from 14hz because I have so much room gain below 20hz), and a 60hz 18db BW LPF:



Nothing new here. Response drops like a rock at 13hz, and there's a huge crater at 50hz just like every other sub I've ever had in this room.

New video in order yet?

This is the one that convinced me to go with the LMS-U in the first place:

post #484 of 758
Thread Starter 
Sadly for my house, a single GH moves that supporting wall even more...

I'm not sure why, but ported, and now horn, subs have always shook things more in my house than sealed subs.

Before I can take a video of both really going, my wife will have to be out of the house. She'd kill me if I did that while she's home.
post #485 of 758
Quote:
Originally Posted by lukeamdman View Post

Sadly for my house, a single GH moves that supporting wall even more...

I'm not sure why, but ported, and now horn, subs have always shook things more in my house than sealed subs.

Before I can take a video of both really going, my wife will have to be out of the house. She'd kill me if I did that while she's home.


F***** Yes!

Here is one I posted up in my thread I though you would enjoy.

I actually thought about your video when I shot this...lol
post #486 of 758
So how bad for your house is it for subs to do that to your walls? I don't want my house to fall apart on me but I want a G horn.
post #487 of 758
Thread Starter 
Quote:
Originally Posted by popalock View Post

F***** Yes!

Here is one I posted up in my thread I though you would enjoy.

I actually thought about your video when I shot this...lol

WOW!! That's impressive!!

That room isn't even close to "sealed" at all either...

That scene is 10hz, correct?
Quote:
Originally Posted by Pain Infliction View Post

So how bad for your house is it for subs to do that to your walls? I don't want my house to fall apart on me but I want a G horn.

It's not like I crank it to 130+db every day, but it will if you want it to.

I was experimenting with the two GH today, seeing what 125+ db at 20hz would do to that supporting wall and...I broke the trim off a door upstairs...

The cones at that point only looked to be at about half excursion...
post #488 of 758
Quote:
Originally Posted by lukeamdman View Post

WOW!! That's impressive!!

That room isn't even close to "sealed" at all either...

That scene is 10hz, correct?
It's not like I crank it to 130+db every day, but it will if you want it to.

I was experimenting with the two GH today, seeing what 125+ db at 20hz would do to that supporting wall and...I broke the trim off a door upstairs...

The cones at that point only looked to be at about half excursion...

Pictures or it didn't happen!!! tongue.gif
post #489 of 758
Thread Starter 
Quote:
Originally Posted by yelnatsch517 View Post

Pictures or it didn't happen!!! tongue.gif





The gap is over 1/4"
post #490 of 758
can someone provide a contact to the cabinet maker who is willing to build these please? You can pm me the price too. Luke did you use the LMSR 18 IN YOUR DUAL GH? Thanks in advance.
post #491 of 758
Quote:
Originally Posted by lukeamdman View Post





The gap is over 1/4"

Am I a bad person for looking like this biggrin.gif when seeing those pics?
I wish I had a system that could do that. tongue.gif
post #492 of 758
Quote:
Originally Posted by lukeamdman View Post

I got the other one powered up and ran some measurements with each cabinet in the exact same position in the room. The results were excellent.

The phase was completely identical at every frequency, and for SPL, the only time the lines weren't identical was a slight 2-3db bump on one around 100hz. Much better than I was expecting!

Here's the response of both using only Ricci's basic EQ recommendations. 15hz 18db BW HPF (bumped it up slightly from 14hz because I have so much room gain below 20hz), and a 60hz 18db BW LPF:



Nothing new here. Response drops like a rock at 13hz, and there's a huge crater at 50hz just like every other sub I've ever had in this room.



That doesn't look too bad. It is possible that you may be able to fill that 50Hz area in with some other subs with different placement. I suspect that suckout from 40-60Hz is making your system lack some of that "punch" you are looking for. Kick drum fundamentals and the bottom of the bass line often fall in that range. Just throw aesthetics out the window and put an Othorn nearfield. That should clear the lack of punch right up. biggrin.gif

Have fun and try not to break your house. smile.gif
post #493 of 758
Quote:
Originally Posted by kutlow View Post

can someone provide a contact to the cabinet maker who is willing to build these please? You can pm me the price too. Luke did you use the LMSR 18 IN YOUR DUAL GH? Thanks in advance.

Well...I will probably be selling my original pair of GH's soon. (Or attempting to anyway. rolleyes.gif)
post #494 of 758
Thread Starter 
Quote:
Originally Posted by kutlow View Post

can someone provide a contact to the cabinet maker who is willing to build these please? You can pm me the price too. Luke did you use the LMSR 18 IN YOUR DUAL GH? Thanks in advance.

Yes, the TC Sounds LMS 5400 Ultra 18":

http://www.parts-express.com/pe/showdetl.cfm?partnumber=293-666

I see the price went back up to $925, too.
post #495 of 758
Thread Starter 
Quote:
Originally Posted by Ricci View Post

That doesn't look too bad. It is possible that you may be able to fill that 50Hz area in with some other subs with different placement. I suspect that suckout from 40-60Hz is making your system lack some of that "punch" you are looking for. Kick drum fundamentals and the bottom of the bass line often fall in that range. Just throw aesthetics out the window and put an Othorn nearfield. That should clear the lack of punch right up. biggrin.gif

Have fun and try not to break your house. smile.gif

The response from 15-40hz is actually smoother than my quad 5400 setup. I'm very pleased.

And yes, aesthetics went out the window a long time ago biggrin.gif

I've experimented with near-field placement in the room and it's the only way to get rid of that 50hz null. Adding EQ boost does nothing but use extra amp for nothing.
post #496 of 758
Any chance to move your seating a little? Sometimes that can help. My room has issues in that same frequency range due to my seating placement (No chance to move it) but luckily I have a gigantic peak and not a suck out.
post #497 of 758
Thread Starter 
Quote:
Originally Posted by Ricci View Post

Any chance to move your seating a little? Sometimes that can help. My room has issues in that same frequency range due to my seating placement (No chance to move it) but luckily I have a gigantic peak and not a suck out.

I'm jealous!

I've moved the seating all over the place, and it doesn't really change. What kills me the most is that anywhere in the room, if I just stand up from sitting, the null is completely gone...

I'm not too concerned, because the 11x29 room all this is currently in is just temporary. When I remodel the basement, the new theater room will be one room over and about 12.5x25. I'm sure everything will change then, possibly for the better or worse. Impossible to predict!
post #498 of 758
Thread Starter 


I agree it's not a good idea to play subs/speakers before the finishing work is done. I just wanted to leave them as-is!



Time for sanding and Duratex.
post #499 of 758
Quote:
Originally Posted by lukeamdman View Post

I'm jealous!

I've moved the seating all over the place, and it doesn't really change. What kills me the most is that anywhere in the room, if I just stand up from sitting, the null is completely gone...

Maybe stack them with the mouth of one horn along the ceiling
post #500 of 758
Quote:
Originally Posted by lukeamdman View Post

I'm jealous!

I've moved the seating all over the place, and it doesn't really change. What kills me the most is that anywhere in the room, if I just stand up from sitting, the null is completely gone...

I'm not too concerned, because the 11x29 room all this is currently in is just temporary. When I remodel the basement, the new theater room will be one room over and about 12.5x25. I'm sure everything will change then, possibly for the better or worse. Impossible to predict!


The best solution is to lift GH to the height of your stand up and the null will completely gone at your ears.
post #501 of 758
Thread Starter 
Quote:
Originally Posted by Fatawan View Post

Maybe stack them with the mouth of one horn along the ceiling

Quote:
Originally Posted by ZivkoF View Post

The best solution is to lift GH to the height of your stand up and the null will completely gone at your ears.

Anything that requires stacking or lifting is going to have to wait until it's the Othorn being stack or lifted. The Othorn, while still a hefty 240lb's, is probably a good 100lb's less than the GH!
post #502 of 758
Hey Luke nice job on those. Have you tried changing the distance in the receiver for the subs to see if it changes the null at 50Hz?

Those look like a washer dryer set in size lol. Can't say much here since dts-10s look like refrigerators. cool.gif

Wish we took vid or pics of a single dts10 destroying our dining light in it's near field.
post #503 of 758
Thread Starter 
Quote:
Originally Posted by autox320 View Post

Hey Luke nice job on those. Have you tried changing the distance in the receiver for the subs to see if it changes the null at 50Hz?

Those look like a washer dryer set in size lol. Can't say much here since dts-10s look like refrigerators. cool.gif

Wish we took vid or pics of a single dts10 destroying our dining light in it's near field.

Yes, I've messed with the distance quite a bit. Doesn't change that dip one bit.

After I get everything positioned where I want it and get the gain levels matched, I always run Audyssey for the sole purpose of it setting the proper distances. It's always spot on. I can literally move something a matter of 1-2 inches and Audyssey can detect it.

The null does decrease the closer I get to the wall on either side of the couch, so if I move the mic just a few feet to the left or right it gets slightly better.

I'm going to try putting the horns in the back of the room and see what that looks like.
post #504 of 758
Re-guarding your null... I've been studying up on acoustics and this could explain your issue. This is just a cut and past of someone else's text from my notes - sorry I can't give credit to the original poster....

Quote:
Whatever frequency corresponds to 1/4wavelength as the distance between the speaker and the front wall ... you will have a null at that frequency. this is because the distance traveled from speaker to front wall is 1/4wavelength, and the reflection off the front wall back towards the speaker is another 1/4wavelength, totaling 1/2wavelength which will combine destructively (out-of-phase) with the original signal - creating a null. the further the speaker is from the front wall, the lower this null will be (and thus, the harder it will be to treat with porous insulation). this is one reason for soffit/flush mounting of the speaker.

for example,
if the distance between your LF driver and the front wall is 34" (1/4wavelength), then 4* 34" = 135". 100hz has a wavelength of 135" so it is possible you will have a null at 100hz due to SBIR. this is true for the LF reflection off the front wall as any other 1/2wavelength reflection path off the floor, front side walls, front wall, etc...

bear in mind you can also have this type of scenario with regards to the listening position and the rear wall (LBIR). you can have a null at whatever 1/4wavelength frequency corresponds to the distance between the listening position and the rear wall. the original signal hits the listening position, travels past towards the rear wall (1/4wavelength distance), reflects off the rear wall and traverses back towards the listening position (another 1/4wavelength distance) - and destructively interferes at hte listening position 1/2wavelength out-of-phase.
post #505 of 758
Thread Starter 
Quote:
Originally Posted by steve71 View Post

Re-guarding your null... I've been studying up on acoustics and this could explain your issue. This is just a cut and past of someone else's text from my notes - sorry I can't give credit to the original poster....

That's some good info, BUT, does it explain how me moving strictly on the vertical axis eliminates the null? If I simply stand up, the null is gone. My distance to the speakers is still the same, and obviously so is the distance of the sub to the walls. I just simply raised my head about 3ft.

It's also not a phasing issue between speakers. The null is there with the mains and both subs playing, as well as just a single sub with nothing else turned on. All in all I've had over 10 different subwoofers in this room over the years, same null with all of them.

Again, I'm not too concerned because this room is only temporary. I'm sure the new room will have new problems of its own smile.gif
post #506 of 758
Hi Luke,
Have you tried them with the horn exits on top? Then you could try facing them forward and backward toward the wall.
post #507 of 758
Thread Starter 
Quote:
Originally Posted by RMK! View Post

Hi Luke,
Have you tried them with the horn exits on top? Then you could try facing them forward and backward toward the wall.

I have not, but it's certainly worth a try!

At the moment, the subs are getting sanded and painted, so it'll be a few days before I can try.

I'm thinking about building a low profile platform on wheels so I can easily "roll" these things around easier.
post #508 of 758
Quote:
Originally Posted by lukeamdman View Post

That's some good info, BUT, does it explain how me moving strictly on the vertical axis eliminates the null? If I simply stand up, the null is gone. My distance to the speakers is still the same, and obviously so is the distance of the sub to the walls. I just simply raised my head about 3ft.

It's also not a phasing issue between speakers. The null is there with the mains and both subs playing, as well as just a single sub with nothing else turned on. All in all I've had over 10 different subwoofers in this room over the years, same null with all of them.

Again, I'm not too concerned because this room is only temporary. I'm sure the new room will have new problems of its own smile.gif

I missed that part. Must be a room mode and there are axial, tangential and oblique modes, so it looks like it's rather involved. As you suggest, wait to see what issues your new room has.
post #509 of 758
Quote:
Originally Posted by lukeamdman View Post

I have not, but it's certainly worth a try!

At the moment, the subs are getting sanded and painted, so it'll be a few days before I can try.

I'm thinking about building a low profile platform on wheels so I can easily "roll" these things around easier.

Yeah, by comparison my 177lb OS's are lightweights wink.gif
post #510 of 758
Quote:
Originally Posted by lukeamdman View Post

That's some good info, BUT, does it explain how me moving strictly on the vertical axis eliminates the null? If I simply stand up, the null is gone. My distance to the speakers is still the same, and obviously so is the distance of the sub to the walls. I just simply raised my head about 3ft.

It's also not a phasing issue between speakers. The null is there with the mains and both subs playing, as well as just a single sub with nothing else turned on. All in all I've had over 10 different subwoofers in this room over the years, same null with all of them.

Again, I'm not too concerned because this room is only temporary. I'm sure the new room will have new problems of its own smile.gif

Reflections are not just horizontal. A null can be created from reflections off the floor and ceiling. What you have is most likely a room mode.
What room treatments do you have in that room? Just out of curiosity and for experiment, try dangling several bass traps from the ceiling and take some measurements.
You probably wouldn't leave those permanently, but it's definitely worth the information if you encounter something similar in your next room.

Here's a link to some info on room mode.
http://www.realtraps.com/art_modes.htm
Notice particularly the quote from the below test done in an empty garage:
Quote:
What we found was that at very low frequencies - below about 160 Hz - the room is dominated mainly by modal response. Above that virtually all of the peaks and nulls shifted in relation to the listener's distance from the rear wall.

Edited by yelnatsch517 - 4/26/13 at 1:54pm
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