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

Interesting inputs and planning :) regarding stuffing and how well it works down there guess also you simply need it for the virtual volume it adds to keep box size about the same as the feet furnitures or am i wrong here.

attachment.php
 

Attachments

  • 11.PNG
    11.PNG
    282.3 KB · Views: 364
Nope, very true... I've asked if I needed to hide my subs in these same canvas covers. This won't be needed so I "grew" with the sub size: 3 cm in all directions :D.

These feet bench are 37 cm x 37 cm x 35 cm. My subs will be 40 cm x 40 cm x 40 cm (outside).
Still unsure about the feet (I want some kind of decoupling there). The feet used on my arrays are NLA as it seems.
 
fluid,
I'm not sure that the stuffing works well at all at the extreme lower frequencies to make any real difference in loading. What I am saying is down around the fs of the driver in an enclosure I don't think adding stuffing makes much difference, up higher yes but at the extremes which is what a sub is really all about does it really do much? I unlike others would never use a sub that was not bandpass limited, I don't want that cone making mid bass or anything else, just the lower bass please. integrating a sub that makes any perceivable higher frequencies with another enclosure is a sure headache and something to be avoided if at all possible.

I don't think you have understood what I said. Stuffing a sealed sub has nothing to do with that. The stuffing changes the virtual size of the box so it appears to the driver that it is in a bigger box. This has quite a measurable effect as it can change the Q of the box significantly. If you don't plan or model for it you might end up with something very different than you imagined.

Look at the bottom of this page for some figures from Troels on his damping experiments. The page is not just all about ports.

Port Calculation
 
fluid,
I actually plan on using a stuffing in my own speaker design I am doing, in this case the enclosure is substantially smaller than optimum. At the same time I am expecting to use something like a Linkwitz Transform to bump up the bottom and a lot of extra amplifier grunt to power that low end. Getting good solid bass doesn't come easy if it sounds great and it can go loud enough for the application without distorting. I have some really unusual ideas for stuffing my enclosures actually, I am going to have a somewhat constrained layered stuffing, it will not be loose fill material though.
 
fluid,
I actually plan on using a stuffing in my own speaker design I am doing, in this case the enclosure is substantially smaller than optimum. At the same time I am expecting to use something like a Linkwitz Transform to bump up the bottom and a lot of extra amplifier grunt to power that low end. Getting good solid bass doesn't come easy if it sounds great and it can go loud enough for the application without distorting. I have some really unusual ideas for stuffing my enclosures actually, I am going to have a somewhat constrained layered stuffing, it will not be loose fill material though.

Wesayso has shown that dissimilar damping materials can have a benefit so no reason why it wouldn't work.

Troels results were with foam and panel damping not complete fill, so adding extra loose stuffing to fill completely should increase apparent box volume even more. Could be useful with a very small box.
 
I designed my enclosures with very stiff internal ribbing that will also serve to capture the stuffing. I plan on die cutting the stuffing and strategically placing those cut pieces into the enclosure. I could theoretically almost fill the entire internal space with stuffing and keep it away from the actual driver so it doesn't touch, that will be determined experimentally.
 
Be aware that Koldby is trying to put together a group buy of the TG9 driver.
Somewhere in the range of $6-7.ea ...plus shipping I assume.
Perhaps he'll chime in here about that.
M

I am on vacation on the Canaries , therefore the late response.
Up until now , there has been to low interest in a group buy.
If I count everything together it only adds up to about 500 units at most, and the min buy is 2026 units.
So unless this can stir up much more interest, I don´t think I can make it happen.:eek::(
 

TNT

Member
Joined 2003
Paid Member
I am on vacation on the Canaries , therefore the late response.
Up until now , there has been to low interest in a group buy.
If I count everything together it only adds up to about 500 units at most, and the min buy is 2026 units.
So unless this can stir up much more interest, I don´t think I can make it happen.:eek::(

Did you really create a new thread for this so that the interest can be judged? If so, please point to it. A structured "assault" will probably give better results?

//
 
I am on vacation on the Canaries , therefore the late response.
Up until now , there has been to low interest in a group buy.
If I count everything together it only adds up to about 500 units at most, and the min buy is 2026 units.
So unless this can stir up much more interest, I don´t think I can make it happen.:eek::(

2026 is a big number... a separate thread might gain more traction though. Where to put that thread might be difficult. There might even be more interested traffic in multi way than the full range section of this forum...

This side of the forum is mostly about using "a" full range driver, not many. :)

There is plenty of interest in arrays nowadays, I just hope that people that build them are willing to stick with them for a while and really try out some things. For many it seems building speakers is the biggest part of the hobby. I still think we can get ahead with any design we choose by analysing it and keep working on it.

I've heard so many sounds produced by my arrays, some of which I'd rather forget. The difference was the processing. It remains a very specific part of a project like this. It can make or break the results. It has everything to do with our perception of sound.
I'd hate to see arrays get a bad name trough people giving up on them early. Invest the time, trust measurements and figure out how we listen.
The rewards will be there, trust me? ;)
 
Last edited:
I think I will try to create a new thread, when I return. Maybe also in other forums, pointing @ the main thread in this forum.
Another issue is, I am located in Europe , so the purchase will be here, so there will be additional shipping cost to overseas countries. But anyway, lets try it and see what happens..
 
The metal frame is somewhat smaller than the wood. There will be a layer of neoprene to fill up the gaps. Inside the (unequal) squares MLV will be glued in. Bolts and nuts will put it all together. Only the front and back will remain removable.

How much popcorn? A lot, actually. It will be a while before I have enough time available to start the actual build. Still busy sourcing possible suppliers for the materials and figuring out how I can make it all come together. I can hardly wait to get busy. Seeing your build pictures does not help :). Makes me want to start right now! I expect to get busy at the end of April, early start of May.

Knowing how I want to do it is half the work though. Still working out the little details in my head. Once I'm satisfied with the plans I'll start ordering.
 
How much popcorn? A lot, actually. It will be a while before I have enough time available to start the actual build.
:sigh:

Seeing your build pictures does not help :). Makes me want to start right now!
Do it!

Knowing how I want to do it is half the work though. Still working out the little details in my head. Once I'm satisfied with the plans I'll start ordering.
So true, I spent a very long time thinking through what I wanted to do before I started.
 
Gassit,

I noticed today, at least, that the TC9FD18-08-ND drivers are back to AUS $12.34 each in quantities of 50 units on the Australian Digi-Key site. Maybe this fluctuating price is a Digi-Key 'thing'? I have seen similar with other large international distributers.

Just checked too.
The price here is now $16.09 @2016 units and they have even labled it as a subwoofer!!!

So no reason to start a group buy. It seemed to be too good to be true anyway, even though they confirmed the low price , when I contacted them by phone a couple of weeks ago :confused::rolleyes: