The making of: The Two Towers (a 25 driver Full Range line array)

[wesayso]

djk (rip) was impressed with the big western electric 15a...............
and he was hard to impress.

could use some eq, but dynamics and immediacy !!

I'd put dynamat on the outside of the horn and felt where the horn walls come together at 90 degrees, or any breaks in the horn path by the mouth.............

That looks like something my girlfriend might enjoy! .
(may djk rest in peace, pretty awesome work though)

 

[perceval]

Metaplugin does what it needs to do and I have free upgrades regularly . It was an old linear phase EQ tool that does not want to work well in a 64 bit environment.
Metaplugin accepts it (it can bridge 32 bit VST's) but I cannot get the complete GUI to show to properly use it. In other words useless. I'm currently working to use another linear phase EQ tool, but all Q factors differ so it is a labor of love to find the right values.

oh, sorry, I thought it was MetaPlugin.
Well, for EQ, one of the best option is FabFilter Pro-Q. Very well designed. Not cheap.
But I recently downloaded a new demo, the Kirchhoff-EQ, still not cheap! Looks promising, but haven't had time to play with it yet. Might be worth a look:

https://www.threebodytech.com/en/products/kirchhoffeq

 

[ra7]

Hey, I could use a linear phase EQ tool. Which one are you using, Wesayso?

 

[wesayso]

FabFilter Pro-Q 2, that's the one I use now for linear phase anyways. I can vouch for it working well .
I had this running in zero latency mode (IIR) for pré EQ for years. Never took the time to work out all the Q difference to swap out the old EQ.

 

[wesayso]

I've made the switch to Windows 10 (yeah I know, still one version behind) from Windows 7 and thoroughly regret the move. It doesn't hurt me on the audio side, but I have to find several cures on the movie side where, despite my use of a powerful enough RTX 3060 TI, I suddenly can't run 4K of MadVR madness anymore without weird hick-ups. It looks beautiful picture wise, but I get sudden dropped frames and strange render times etc. Never had that problem with Win 7 Pro.

Found the cure(s)... first step: disable all the extra stuff that Windows 10 does to video:

While I hate a Dutch OS, it's what I got when I bought this system. Anyway, the high dpi scaling override must be set to "Application" and Optimizations for full screen set to "off" for both MadVR's exe as well as Jriver's exe file. Next I disabled some gaming options within Windows for recording the screen and set Nvidia's VSync to "On" for both JRiver and MadVR. Now I can have my cake and eat it too! The quality of the rendered images by MadVR is awesome, I get to set the black and while limits to match the screen which makes the images "pop" and look real good. That's why I bought the Oled screen, deep blacks and good dynamic range...

If I ever go to Windows 11, this post will remind me what to look for .

All is well again, almost... still need to re-install a boat load of apps that didn't make it trough the win7 -> Win10 upgrade. Like all my 3D design software etc.
Audio and Video is working again, so playtime can begin....

Now running on Win 10 (pretty current, while not quite current) and JRiver 64 bit with audio working as well as before. Well worth the troubles, the last big upgrade was years ago. Fabfilter does as good as the previous linear phase EQ and can set an even bigger number of tabs (good for low frequency resolution in higher sample rates) with the penalty of more delay. That isn't a problem though, as Audio/Video sync is done by JRiver.

 

[wesayso]

Watched a couple of movies with the above tweaks in place... running on Win 10 and playing HT is now officially working.
Still have to reinstall a lot of apps, but music and Home Theater is working, just in time for the Holiday season.

In another thread I was reminded of something due to John posting about it (again); using a single tweeter for stereo listening:

About fifteen years ago, some PHD student in Florida published an interesting paper that indicated that listeners couldn't easily discern between stereo tweeters and mono tweeters.

IE - you can have ONE mono tweeter in the center of two stereo speakers and people couldn't easily tell the difference.

If you think about it, this makes a lot of sense.

First off, when you have stereo speakers radiating 10khz, even the tiniest amount of offset will generate comb filtering. 10khz is 3.4cm long, which means that if you move your head just 1.7cm (0.675"), the radiation from the left speaker will cancel out the radiation from the right speaker.

The other issue is that our perception of where high frequency sounds are located is determine by frequency response, not phase. If the left speaker is 3dB louder at 10khz than the right speaker, our perception of where those sounds are coming from will veer to the left. But as noted above, simply sitting an inch or two off-center will screw up that frequency response.

Put all of that together, and you can see why a single mono tweeter may be ideal. Or if not ideal, it sounds comparable to a set of stereo tweeters.

I tried this years ago in my car stereo, and was surprised by how convincing it was.

This seems like a fun idea to try if I ever find the time and can do it in a way that my girl doesn't notice the added (single) tweeter. Would be fun to have it play 10 KHz+, though if it has to be concealed, even the tweeter will probably be beaming at those frequencies. Maybe it could work, aiming it up in the center, hidden behind the TV screen... It would light up the room more than be a direct source.

I never missed it (the tangling or sizzling top end of tweeters), but I didn't miss the subwoofers either .

 

[wesayso]

Speaking of subwoofers: one difference between the TC9 array and the new 10F array is in how they work through their resonance region. I could play the TC9 full range without running into any kind of trouble, but never managed to do (exactly) the same with the 10F. I thought I should mention that. I even upped the subwoofer's crossovers to adjust for that. So they do act different. I thought I should mention that. I always suspected the 10F to win the battle from 200 Hz and up and the TC9 doing better below that (for this line array duty).
Due to the 10F being a hair more efficient than the TC9, I have removed the Atom pré amp I used to run between the DAC and the big amplifier. Not needed in this application, I removed it quite a while ago. So that does influence the build of the 6 channel pré-amp I was going to do. As it's not really needed anymore at this time.

 

[Pano]

djk (rip) was impressed with the big western electric 15a...............
and he was hard to impress.

Back in ‘87 I helped stage demos of a large system built around the 15A - in my theater in Paris. It is still my reference system, I’ve never heard anything else close to that good
But I’m easy to impress.

 

[Pano]

Maybe it could work, aiming it up in the center, hidden behind the TV screen..

Not easy to do. Years ago I did a lot of experimenting with bounced tweeters because Mr Linkwitz was using them.
I found that horns were a must. So much energy was lost in the bounce that the initial levels had to be rather high.

Fun to play with, but not as easy to get good results as I had hoped.

 

[wesayso]

Indeed... that is the biggest worry I have, I did think about a removable or pivoting construction that could give me a B&O like tweeter waveguide.
Could even make it pop up like they did in Audi dashboards...

What do you know, it is available at certain specialist outfits. That might work (lol).

 

[wesayso]

I read your reply on that full range or tweeter thread @Pano. I can agree with that for a large portion. I always had trouble with tweeters to make them sound right to me. They simply drew too much attention to themselves. I think I had the most succes with Vifa ring-radiators + EQ. I could see me do a small waveguide and one of those tweeters on a pivot construction behind the TV screen. Pivot it up if needed, could even work for Home Theater, even though I doubt it has any value for me in that application.
At least the ring radiators work pretty good in the right waveguide. I remember seeing measurements of lots of those type of waveguides from Dave Pellegrine in the past... I'd want one that limits the verticals though... Maybe go for AMT or Ribbon? I'd only need 10 KHz+.

 

[Pano]

I used Fane ring radiators on my Altec system. Crossed at 7 kHz and at the right level they were a welcome addition. Not fake at all. I did try bouncing them to spread them around but never had much success. I seems like a good idea, but takes more effort than I was willing to give it.

 

[adason]

Hi wesayso, if you are thinking about an experiment with adding a tweeter/supertweeter to your line array, my suggestion would be to try one inexpensive yet well performing foster planar. I used it in three systems, and i like what it adds on top.
I will try to find links.

 

[adason]

Here is fostex planar on top of big hivi planar tweeter, crossed at 10kHz, just for more uniform dispersion, as big planar starts beaming above 10k.
https://www.diyaudio.com/community/threads/viral-projects-sort-of.351475/post-7109810

Here is fostex used on top of grs slim planar. 9kHz crossover. Some measurements included.
https://www.diyaudio.com/community/threads/viral-projects-sort-of.351475/post-6726107

Here used in line array...
https://www.diyaudio.com/community/threads/foster-e100t10-ribbons-what-quality.113262/

 

[wesayso]

Hmm... shipping to NL is adding 2x to their price, but it might still be fun to play with them.
Can't seem to find them closer to home, but your testimony and measurements make them look attractive for such a trial project.

 

[wesayso]

Bought a pair to play with. Still planing to use a single one in mono, but a back-up isn't that bad to have at these prices.

Let's see if I can use a bit of sparkle up top . Will have to think about an amp for this experiment though.

 

[wesayso]

That time of year again, a happy 2023 to all!
May there be lots of great music and good health to enjoy it for all.

 

[wesayso]

Quite a few days ago I received the ordered tweeters. I'm impressed with their weight, looks etc. It will take me a while to try them out. Flu season has got me. Still wondering how to use them.
Do I use one (in the center), in mono firing directly at me, as a substitute for the top end of the arrays?
Do I use one, firing at the front wall as ambient super tweeter?
Do I use both, each on top of the arrays, pointing back at the front wall/ceiling as ambient tweeters?

I can cross them appropriate, I can delay them etc. I think I feel best about using both as ambient (super) tweeters on top of the arrays.

Next point: what kind of amplifier do I need to come up with to do these some justice... Ahhh, the problems of excess...

 

[TNT]

Perhaps someting along these lines... https://www.diyaudio.com/community/...-composite-amplifiers-based-on-lm1875.382575/

//

 

[perceval]

Do I use both, each on top of the arrays, pointing back at the front wall/ceiling as ambient tweeters?

this would be my choice... wouldn't need much to power them, just something clean.