Yet another IDS-25 clone?

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I’ve fallen deep into this rabbit hole after stumbling the other day onto roger russell’s website. I need to experience this for myself, so figured I should start my own design/build thread.

I’ve read pretty deep into wesayso’s trials and tribulations, and learned a fair bit about a few major pitfalls...

Lots of places to start here, the drivers being one. I’ve got some looking to do and to decide what is the best price to quality ratio that I can afford at the moment. The Dayton audio PC83-8 looks like a possibility, along with the ubiquitous Vifa speakers used in the original and by many others.

I’m planning at the moment to go with a simpler design than the two black towers. I’ve done enough woodworking to know not to fight the natural inclinations of wood, and I also don’t want to turn so much material into sawdust, even though I can get Baltic birch ply for very good prices (cheaper than all the home center crappy ply by a good margin). I prefer dark woods like mahogany and walnut, but need to figure what I want to live with. Laminating steel or aluminum to wood is also an option, and would deter the cats from using it as a pair of monumental scratching posts :) I’m a sculptor by training, so i’m looking at this as an opportunity to build a functional piece of art, though function and good sound are more important to me, I will have to look at these things.
 
In terms of internal volume, I see numbers of about 2 liters per driver for these speakers. Is there a reason not to go larger?

I’ve got a mind to simply build the tapered box that roger Russell did for his, but am also considering the things that can be done cutting groves into the wood and bending it around internal bracing. Over such a great height as 8 feet, I’m not interested in the pitfalls of stackable design, even though I’ve got a CNC router that would make the parts for me relatively effortlessly.

How much advantage is there to making an interior surface with irregular surface? I plan to use fiberglass batts inside for damping, so wonder if the extra effort of making the irregular surface brings noticeable added benefits? I imagine on an empty cabinet, it would make a lot more difference than a stuffed one.

I’m also curious about how much effort to put into the baffles inside between the drivers. Do I want that space relatively open and connected, or is it better to make the drivers more isolated from one another? I can easily make baffles/braces with any size, number, and shape of holes between them. Do these holes between the braces need the extra effort of rounded smooth edges, or can they be left square/as cut?
 
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Want to make something even better than Mr Russell's IDS-25? Just read the tome or textbook on the topic by Wesayso in this thread:

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

There is a recipe in there and if you follow it, you will be rewarded with, and I kid not, perhaps the finest sounding speaker in the world, anywhere, any price. I have heard it myself and it is simply staggering and mind blowing what the sound quality and realism is like.

But there are a lot of fine details and much of it requires real time DSP to realize. A lot of it requires room treatments. Lot's of little things that when all pieced together, yield a sum greater than their parts.
 
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I’ve read pretty deep in, and unfortunately because it’s gotten so long, there’s a lot to sort through in order to get to the information that is most helpful. If for some reason I decided to go with a stacked design, I would do it without the rods. The wood ought to be plenty strong without them, and it can then move as it wants to. Front mounting plate/baffle could be made out of wood and remain plenty strong, but if done from wood, it would need to be oriented the same way as the wood in the stack so that they could all move together. His stuff looks and probably sounds magnificent, but I don’t think that comes necessarily from the fiberglass reinforcement that he did to keep the column from expanding and shrinking with humidity changes. A properly designed wood/MDF/particle board enclosure can be built without the fiberglass. It’s tempting to make from solid wood, since it wouldn’t move appreciably in the length, only across its width, but I don’t think it would have as good damping properties as equivalent engineered wood products would have. Part of me wants to go with minimalist boxes that could be painted the same as the walls, and mounted directly to the wall on a bracket that would allow them to be rotated. There definitely going to take up a lot of space visually even though physical footprint is very small.
 
Another line array build... :)

I have recorded most of my journey here, in my thread. This is going to be your journey, so that means your decisions. I do not regret anything I've done, however there were a couple of lessons to learn.

If I were you (and I'm not) I'd build a free standing array so you can play with positioning to get the least amount of early reflections while still keeping the help in the bass department from the wall behind it. Some shuffling and rotating of the end product might be involved to get the best results.

My credo has been: every little detail is important. I wanted to build something that could do better than good. So I've thought about it for over a year, reading every paper and article I could get my hands on. Based on that info, I started planning my build.

I'd say try and keep diffraction in mind for the design, also test your enclosure idea by making a single driver box first and see how you can clean up the impedance of one speaker driver in that box.

I highly recommend the Vifa TC9 FD18-08, it won't be easy to top that driver. If you want something even closer to the IDS, than the TG9 FD 10-08 would be hard to beat. That would be the 8 ohm driver's name, the 4 ohm variant usually is easier to get a hold off, but I'd recommend the 8 ohm version. For a smaller driver (better to combat combing) the (more expensive) SB65WBAC25-4 gets a lot of traction these days. It is quite a bit smaller than the Vifa/Peerless drivers (good for high frequency, maybe bad if you want the bottom octaves to come out of the array).

Many other drivers have been used, it will be your call. I'd say listen to it, whatever you choose, you're going to get it back on steroids in an array ;).

You can find many threads on arrays here on the forum, lots to read! Take your time and don't rush in, if all goes well it just may be the last speaker you ever need. :)
Look around your room, where would they fit? How can you place them? If you want to limit/absorb early reflections, would it be possible with some simple panels?
Think of your room with the speakers as a system designed to work together. With some care you can do better than the IDS.

Above all else: have fun!
 
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I was just looking at drivers, and this little guy popped up: Aurasound NSW1-205-8A 1" Extended Range

High Frequency response curve looks a lot cleaner than many others, and other than the 15db or so dip between 30-200hz, seems to look pretty good on paper. That kind of dip seems like it would be easier to smooth out with equalization boost, or maybe some way of porting it? I know this is stealing away from original intent, but seems like an interesting driver, in that it is so small, and one could cram so many into an 8’ space :)

The other thing I’m strongly considering is to do the line array with subwoofer for lowest bass notes. I don’t watch a lot of tv/movies, but maybe I’d do more if I had capable speakers.

I want to keep the equalizing analog, mostly to reduce complication in the amount of equipment I need. I feel confident that I can build those components well enough to satisfy my listening needs. Digital signal processing is a rabbit hole i’m Not willing to go down at the moment.

I’m going to order a few drivers and see what I like, and see where this takes me. The little 1” drivers from aurasound are a little pricey for what I want to spend on this project at the moment, but I’m interested to see what can be done with 1 inch “woofers”. The travel on them is seems very big for something that small, and I’m curious to see what they will do without blowing up.

Part of me is thinking to just buy a bunch of the cheapest 3” speakers, and throw something together out of MDF just to see what they sound like. The hardest part in building is going to be cutting 25+ holes per speaker in the front baffle, and this is a relatively trivial job with the CNC router. I should probably go minimalist like this, and see if I can eek out a set of speakers from a single piece of MDF. Refine and tweak from there.
 
High Frequency response curve looks a lot cleaner than many others, and other than the 15db or so dip between 30-200hz, seems to look pretty good on paper. That kind of dip seems like it would be easier to smooth out with equalization boost, or maybe some way of porting it?

The dip is not a dip it is the driver rolling off from 300Hz down you can equalize it in the same way as the TC9 but more EQ would be required due to the higher rolloff point.

The TC9 is a pretty special driver for the price, it has good and smooth off axis response, many have looked for other drivers but it is hard to beat for this application.

2 litres is about the right volume for it, due to the high Qts of the driver it takes much more volume to have any real effect which makes the cabinet impractical.

The effort and cost of other components needed to get a line array built makes it not worth doing with drivers any cheaper than the TC9, when buying 50+ the price is quite good.

Analogue EQ will only get you so far, I have heard mine with varying levels of EQ from a rough guess to the full wesayso treatment, the full EQ treatment really makes an improvement.

I don't know if you have seen my thread but it may be helpful as mine was CNC cut out of MDF Full Range TC9 Line Array CNC Cabinet It also ended up being quite long ;)
 
The dip is not a dip it is the driver rolling off from 300Hz down you can equalize it in the same way as the TC9 but more EQ would be required due to the higher rolloff point.

seemed interesting that at least in their curves, it perks back up and goes up a bit below 30Hz.

Anyway, sadly the TG9FD in 8Ω is not available from the big parts sellers quantities less than 2000 for a reasonable price. I'm going to check a few others like mouser and digikey and see what they have before buying. I'm going to have to be careful not getting too many drivers to test ($$$ that could go to the price of the finished speakers), though I figure I can build some nice bookshelf speakers with them and give them to friends or sell if they don't sound terrible.

I'm also tempted at some point to see what can be done to make a desk to ceiling mini line array for my office computer, along with the other stuff needed for a mini surround sound/thx setup. with the 27" screen 18-24" from my face, it would be like having a home theater in miniature :)
 
Having looked at the specs for a lot of these small drivers, it seems like the original designer might have picked the drivers he picked because they have such a flat impedance curve. Most of the others available don't seem to come close to that. The only other ones that size seem to come close to being as flat on both the frequency curve and the impedance curve that I have looked at ($23-30 and under) are the Fountek FR88/89 FE85. I'm going to get the Vifa TC9 (easily available and proven) and the Fountek FE85, along with a few others to try out. The founteks are flat(er) to 20khz, but might be much more directional at those frequencies? They don't publish that info, unfortunately. They seem to have a similar roll off on the bass side, though you get better performance with the higher $$$ FR88/89. The main issue with the FE85's is that they don't have much travel, but by the time you've got 25 of them moving together, I would think this isn't such a big deal. I don't have a huge listening space, and don't need SPL's high enough to cause hearing damage... and if they end up getting used at some point for watching movies and I need more bass, subwoofers will get built/bought.

The other issue with the founteks, is that they must be spaced slightly farther apart (or I need to figure an easy way to trim two sides off of 50 speaker mounts (if that is possible while keeping them sturdy. the aluminum cast FR88/89 speakers could be bolted face down to a board and cut on the table saw to make the frames "square".

For now, I need to whittle down the other possible drivers so I'm not spending stupid amounts of money just on tests, and then get some to listen to.
 
Hi anchorman, add me to the list that's just built a line array...in the "Line array steering ?" thread now active too..

I'm using 24 TC9s. I wanted the height on 25, but chose 24 for the divisibility of 24 for multi-amping and playing around.

The PC83-8 looks nice...I never saw it when doing the same search you are now doing. I hope the more experienced can contrast it to the mainstay TC9's.

Box construction FWIW :).....
I was surprised how easy making the baffle board was for a rear mounted design. It was MUCH easier than making the rest of the straight cabinet. i think i could make a pair of baffles in a few hours..
A simple plunge router and a couple of sacrificial drivers to use for mounting-screw templates made things easy.

I see you say you have baltic birch availability..
Can you get 8 ft sheets ? (as opposed to the usual 5x5)
If you can, I'd use whatever thickness you deem appropriate and make a one piece baffle (i was good with 12mm because I'm happy with rear mounted), along with a long straight box.
And either paint or laminate a hardwood veneer. (BTW, i get a laminate for cat protection, but how does that help the drivers? )
Me ? I use duratex and auto-body paint...I don't much give a damm Lol

I simply love the dimensional stability of BB...it's hard to find any material that warps/moves less, and cuts so precisely.....


I think you can do very well with just analog EQ.
The biggest trick will be getting enough PEQ's and shelving filters in an analog processor, to do the trick.
If you want to get really exotic with analog, i have a Manley Massive Passive EQ I'm about to put on the market.....
But my recommendation is go DSP...as in 'Go west, young man' Lol

I recommend all the above simply cause it's working for me...that's what we are all doing I guess, huh:)
 
seemed interesting that at least in their curves, it perks back up and goes up a bit below 30Hz.
I see a similar thing in some SB Acoustics drivers I doubt it will hurt in any case.

also tempted at some point to see what can be done to make a desk to ceiling mini line array for my office computer, along with the other stuff needed for a mini surround sound/thx setup. with the 27" screen 18-24" from my face, it would be like having a home theater in miniature :)
Line arrays need some listening distance less than 1 metre and the combing becomes quite noticeable, 2 to 3m+ is much better.

The only other ones that size seem to come close to being as flat on both the frequency curve and the impedance curve that I have looked at ($23-30 and under) are the Fountek FR88/89 FE85. I'm going to get the Vifa TC9 (easily available and proven) and the Fountek FE85, along with a few others to try out. The founteks are flat(er) to 20khz, but might be much more directional at those frequencies? They don't publish that info, unfortunately. They seem to have a similar roll off on the bass side, though you get better performance with the higher $$$ FR88/89. The main issue with the FE85's is that they don't have much travel, but by the time you've got 25 of them moving together, I would think this isn't such a big deal. I don't have a huge listening space, and don't need SPL's high enough to cause hearing damage... and if they end up getting used at some point for watching movies and I need more bass, subwoofers will get built/bought.

The other issue with the founteks, is that they must be spaced slightly farther apart (or I need to figure an easy way to trim two sides off of 50 speaker mounts (if that is possible while keeping them sturdy. the aluminum cast FR88/89 speakers could be bolted face down to a board and cut on the table saw to make the frames "square".

The downsides to the Founteks are the lower xmax on the cheaper ones and the smaller Sd, (Cone area) 27cm2 vs 36cm2 for the TC9. When you add that up over the 25 drivers it makes a difference.

Even without high volume a lot of EQ is being used to wrangle the Frequency response of the line back into shape, which means more power and excursion is being used. These aren't the figures you want to skimp on IMO.

With the bigger frame they could be rear mounted and a small waveguide on the front used like wesayso.

I think you can do very well with just analog EQ.
The biggest trick will be getting enough PEQ's and shelving filters in an analog processor, to do the trick.
If you want to get really exotic with analog, i have a Manley Massive Passive EQ I'm about to put on the market.....
But my recommendation is go DSP...as in 'Go west, young man' Lol

I used about 25 bands of parametric EQ to bring the response close to my target and DRC on top to get the finer grained correction. You can get close with about 6 bands.
 
Line arrays need some listening distance less than 1 metre and the combing becomes quite noticeable, 2 to 3m+ is much better.


I am lucky that where I sit, there is roughly 1 meter to the back of my desk. A mini array setup could easily be done with small speakers, 1-2". I'm partially curious just to hear what something so tiny is capable of doing on its own in a box. people have come a long way with driver technology since anything I own was produced.

As to speaker sizes for the big array, I'll definitely make sure to calculate the total driver size and travel. My needs are less for booming loud noise than high quality at comfortable listening levels. Current speakers (actually the only speakers I've had for the past 25 years or so are Large advents that I got for cheap and repaired the surrounds. My amp is relatively small, a marantz 4220. I'm planning to build or buy something bigger at some point, but I get driven out of the room with that only cranked up about 1/3 of the way as is. I realize I'm going to probably need much more power to shake the room with the line arrays, so I'm going to either need to think subwoofers or bigger amp for that.
 
As to speaker sizes for the big array, I'll definitely make sure to calculate the total driver size and travel. My needs are less for booming loud noise than high quality at comfortable listening levels. Current speakers (actually the only speakers I've had for the past 25 years or so are Large advents that I got for cheap and repaired the surrounds. My amp is relatively small, a marantz 4220. I'm planning to build or buy something bigger at some point, but I get driven out of the room with that only cranked up about 1/3 of the way as is. I realize I'm going to probably need much more power to shake the room with the line arrays, so I'm going to either need to think subwoofers or bigger amp for that.

The point I am trying to get across is that the excursion capability allows you to apply considerable EQ on the low end allowing the line to reach right down to 20Hz or below so no subwoofer is needed to have a truly full range speaker for music listening. As long as the speakers are placed to work with the room the bass shouldn't be boomy or shake anything. The use of that EQ means the original signal has to attenuated to avoid clipping it. Then to get back to a reasonable listening volume more amp power is needed to make up the difference. A line array is only efficient over part of the frequency spectrum, at the top and bottom they need EQ to rebalance the sound which eats a bit of amp power.

By choosing a driver with a smaller Sd and less excursion it has less volume displacement capability and turning the volume up will reach the limits of the drivers that much sooner. Most drivers sound better when they are just loafing along rather that jumping up and down:)
 
I get that the point is not to use subs, but I don’t think it’s necessarily viable for me at the moment to eek out 20hz from my future line arrays. I’ll have to play it by ear and see what they do.

I’ve also got dreams of finally building a few medium power tube amps with a bunch of stuff that I’ve got laying around, and don’t plan to have said amp pumping out more than 50wpc, if that, so have been considering what I’d need to do to get that last octave or two more efficiently. Currently reading up on subworfers so I can take some very slightly informed stabs in the dark at how I might be able to pair them with these. The TC9’s look like they’ll be great drivers, but I’m also looking at the fountek fe85’s and the Dayton pc-83’s.

I’ve also got a few crazy ideas about these little 1-1/2” Daytons, and maybe building a set with 50 per side at some point They won’t do the bass, though, so would have to be paired with something. I’ve got this idea that somehow a set of floor to ceiling line arrays might be able to be paired with some sort of floor to ceiling radiating subwoofer that pushes sound out along a long narrow-ish opening. Or maybe the sub is good enough coming mostly from the floor.?
 
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