all CSS heavyweight compact 3way

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A sports hall is a very eco'ey enviroment... wouldnt you be better of at the top of a hill... or at least in a hot air balloon.

and if that probably isnt possable, surely halfspace in a field is more accurate than a hall that bounces sound around as efficently as a basket ball
I did a gated measurement, that keeps out the echoes.

outside: not with our weather :D and the other noises outside (wind, birds, rain, traffic, kids, wife, dogs, Ronaldo, etc) would introduce too much noise into the measurement.
 
Yes I know the measurements aren't smoothed, however if you take measurements that really are completely free from room measurement artefacts then smoothing isn't necessary.

Such as this, 1) the clean impulse.

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Followed by 2) the completely unsmoothed frequency response.

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Noise at specific frequencies typically shows up in the measurement at the frequency that the noise is at. The OPs measurements look just like measurements that are contaminated by reflections.

For example here's the frequency response of a tweeter with a very short gate first, then longer and longer ones that capture small reflections from the room. The last one captures a particularly bad one, but you get the idea.

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If your response ends up looking like this.

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Then it often means that you've got a noisy system with broadband noise. You can easily reduce its effects by taking say 5 measurements that are then averaged out. ARTA does this automatically if you ask it to.
 

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So, here is the filter schematic:
Trio CSS - filter schema.png

Some clarifications on the main components:
  • the + and - in the driver symbol indicate how they are connected: the mid normal (so driver + on amp +), the woof and tweet reverse polarity (so driver + on amp -)
  • All capacitors preferably >160V
  • For the 8.2mH inductor I chose an I-core type, probably the best price quality ratio of the cored types; aim for the lowest series resistance your budget allows for
  • use air core inductors (foil type if budget allows) for all others, to be sure that you'll achieve the lowest distortion possible; there is no benefit in thick wires (in the mid and tweet sections) so no big dent in the budget and limited benefit from solid cores
  • RCL in tweeter net and the small caps over the series inductors of mid and woof are for the final touch, if budget is tight these can be omitted
  • the 1uF over the tweeter resistor is optional and the effect subtle, let your ears decide
 
Regarding the efficacy of small roundovers, I always look at it this way- if one traced rays from the driver to the edge of the baffle, only those s that are perpendicular to the cabinet edges will encounter the minimum size of the roundover. Those rays that are angled relative to the baffle edge encounter a much slower transition from 2pi to 4pi and thus the small roundover is effective lower in frequency than the nominal roundover size would seem to be capable.
 
while waiting for the "final" filter components to arrive, been playing a bit with the damping and placement of the speakers. first I added more twaron, now there is 200gr elves hair in the woofer compartment. subtle difference, but enough to justify the effort.

placing them proved an issue in my listening room, because I noticed a large difference in bass if I moved my listening position by a foot or so (it was easier to move myself than to move these heavy boxes with the filter free-wired on a piece of wood), much more than I had with other designs. having a deep bass does not make everything easier :rolleyes: to be continued.

but apart from that, I am happier every day with what these deliver. the speakers disappear completely, imaging is among the best I've heard (at least the same as a good fullranger, which is my reference; this really surprised me, never expected that a multi-way could be a match for a full range in this aspect), details are beautiful, instruments :sax: and voices are as if the musicians are in the room playing live. orchestral music is impressive, especially live recordings.

Now all I need to do is to convince my wife that these deserve a place in our livingroom :cheers:
 
did you mean solder on? :D

just received all the final filter components, next is to make some nice prints (a zelfbouwaudio.nl member is making the prints for me) to mount them, and then I'll also finnish the veneer

@Mark: a bit odd to notice that much of the discussion was on details of the measurements, and less on the loudspeaker design or the filtering
 
High frequencies are going to short your amp through the woofer low pass. You really ought to address that, it's dangerous.
thanks. acc to the sim that would only be at very high frequencies, since the impedance stays above 3ohm until >20kHz. But to be sure, I've added a 15ohm resistor in series with the small cap, that should fix that and still keep the function of it:
Trio CSS - filter schema.png


I think people are trying to help him.
I know, and that is also how it feels (and it is appreciated as well), but it's just odd that I got less response on the speaker than on the measurements.
 
I know, and that is also how it feels (and it is appreciated as well), but it's just odd that I got less response on the speaker than on the measurements.

Well you supplied measurements like they were important to the final design (which they should be) then it suddenly becomes a moot point? Sorry but I don't understand what it is you are looking for in a response. Any chance of measurements of the final product?
 
15 is probably tons. I'd even say 2ohms is enough
probaly, but with 15 it will be ~4ohm for upto 30kHz and the effectiveness in suppressing the resonance is about the same.


Well you supplied measurements like they were important to the final design (which they should be) then it suddenly becomes a moot point? Sorry but I don't understand what it is you are looking for in a response. Any chance of measurements of the final product?
it's not a moot point, just expected also responses on e.g. the filter, nothing more. Measurements are important, and comments on those are more than welcome (that's why I post on a forum). I will make final measurements of the complete box when I have the final filter in place, with the current filter (see post #19) it is close to impossible to move the thing.
 
As for measurements, I think issue is that your using GP even at high frequencies. So there is a reflection between the floor and the mic. I personally use GP and near field to about 200hz and then go with a gated measurement above 200hz. 200hz isn't a hard a fast number, it depends on things.

I'm pretty sure Joseph D'Appoliti teach it this way in Testing Loudspeakers which you mentioned. But I could be wrong. I haven't rear that part in a while.
 
I used a gated measurement (Arta) for the entire range, so from 50Hz up. I chose the gate based on what I saw in the impulse response, which resulted in the 50Hz. Maybe there was a small early reflection that I did not notice well enough on the screen that caused the graphs to be not as smooth as the could have been?
 
The mic is about 1cm from the nearest reflection. So you would not see that in the IR. 1cm is insignificant at 100hz, but not at 5khz.
mic is somewhat off the floor due to the shape of the body

....But the stand raising it off of the floor makes for some serious measurement reflections.
why would that be if the mic is on the floor?
 
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