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GAMMA 30 experiement

Oh there is something I forgot to mention, I have talked about a problem with my DIY capacitor foil ribbons, where they would loose their tension just hours after mounting them, causing a peak around 7.8KHz (as far as I remember) a peak I managed to miss for the longest time, I have focused on the 1-5KHz region when testing.

But I have two types of caps that yield usable foil, one with thicker foil and one with thinner foil.
The thin foil has the peaking problem, but the thicker foil doesn't, but it doesn't sound as transparent as the thinner stuff, and I wouldn't consider it ideal either, but not peaky, still not completely flat though, but good enough for now :blah:

So it is possible to make decent ribbons out of capacitor foil, but thinner is not necessarily better.

I still plan on using Howard Dawson ribbons in the future though, unless I can find some high purity aluminum foil of the right thickness, whatever that might be.
 
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I have been listening a lot to my speakers today, for the first time since I moved over two weeks ago.
The room really isn't good, but some genres do work, classical music works, so does some kinds of ambient music.

The crossover filter I'm using now, was "deployed" shortly before moving, I had it in my thoughts for a while before trying it out.

Anyway, it is very very good, no nasty peaks, no obvious directivity problems, no horn shouting, and phase integration is very very good too, just as good as some of the very simplest crossover networks I have made.

It's kind of like an "averaging" of the advantages of the successful filters I have made.

They sound very balanced, flat and coherent, while maintaining the rich shininess and "invisibility" that makes these speakers so very addictive.
In a better room they would also be very very fast (like SUPER fast) but even in this poor room, they sound absolutely effortless and "immediate/direct".

They don't care about genre, but are particularly good with the human voice, drums, electric guitars (anything that is supposed to sound distorted) and anything that has a metallic component to it, be it brass instruments, bells, xylophones, cymbals, sheet metal or concrete mixers.

They just need more bass.

(I used the word "very", very very much here, just to make that clear)

Yeah I really feel immensely satisfied with my achievement at this time.
 
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Today I had a LOUD rockout session for the first time using the new crossover.
It seems that at loud volumes, this room isn't too bad, only the bass gets sluggish and muddy.

Anyway, they play pretty damn loud, without any problems at all.
One track I have used for loud music testing is a song from Rotersand's album "Welcome to Goodbye" called "Dare to Live".
In that song he sings "do you SEE, do you FEEL" when he sings "SEE" the "EEEEE" has been very difficult for my speakers to do right, sounding very edgy, making you want to turn down the volume.
With the new filter, it's no problem at all, so the the worst issue I have had with my speakers is solved.

:banana:
 
Not yet tried, but this is tomorrows project:

f4636e69_Bulins.png


Looks promising!

Edit: there is absolutely no question that my previous filter (mkV), which I'm very happy with, will have superior directivity, this one (mkVI) will be without lowpass though.
It's gonna' be a tough choice if the mkVI filter works as well as the mkV filter.

Do I want fidelity or good directivity?

The questions I have are becoming very specific.

Edit2: also the mkV filter will sound warmer, not necessarily an advantage, ramble ramble I haven't even tested this yet, need to test, MUHAHAHHA more testing to do!! I love testing! :banana::banana::banana::banana::banana:

Edit3: update the picture to show proper polarity for the tweeter, this filter has, erm a phase response that is tricky to figure out, I tihnk it's better this way though.
 
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Tone sweep test passed!

Very exciting!

Edit: tough choice, very very tough choice... this will take a while.
 
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The mkV filter sounds warmer, flatter and deals very well with the directivity issue.

The mkVI filter sounds clearer, the midrange is VERY good, the bass is clearly faster, even in this room, but it has a narrow sweet spot, and is not as flat.
I have no doubt the mkVI filter can play louder too, but that is not importat, both filters play loud enough.

Well good thing no one is forcing me to make a decision now!
 
Huh, what do you know, when I listen to music I made my self, the mkVI filter is CLEARLY superior, it sounds much closer to what my crap sounds like on the K240DF's.

Surprise surprise, this is the kind of thing that weighs heavily in the mkVI's favor.

Yeah, things are starting to look bleak for the mkV filter, flatness (but warm voicing) and good directivity, is just not enough.
 
By the way, did some -=BASIC=- (very basic) room treatment to get better sound, I put a nice thick cushion on the floor between me and the speakers.
I actually started doing that days ago, it is quite remarkable how big a difference such a simple thing can do.

I think I need a discrete device to use in stead though, since my cushion doubles as a night time appliance as well.
 
I had another looong listening session today, like 6 hours straight, only interrupted by a bit of posting on this forum and such.

It has been immensely enjoyable, and I have lost all desire to experiment further with crossovers.
Well... well... I do have an idea for one that should provide better phase integration... I don't have any of the parts for that filter though, maybe some other time if I can't help myself.

The box is next, soon hopefully, but I have no idea when I'll get around to it.

I don't really need much, an MDF baffle that is mounted on the edge of the box, rather then on "rails" like the current one.
This will increase the volume to around 60 liters.
I'll add an MDF plate with four big holes in it as proper bracing.
I need stuffing too, I haven't decided if I'll make my own flow resistors or buy an off-the-shelf solution.
I'll probably get some better terminals too, Gato Audio makes some nice affordable ones.

I'll make the baffle taller then the box, so that I can mount the tweeters on it as well, that would be neat.
 
Yeah, this filter really sounds as if it was meant to be, so it took about a year to finish developing this crossover.

Heh, I could have done this a LOT faster if I had some measuring equipment.
I don't regret doing the way I did though, it has been the toughest critical listening marathon I can imagine.

I really like the impedance characteristic of this filter too.
With an aperiodic box, I hope to keep the impedance in the 5-15ohm range, for a trivial load on all but the weakest of amps.
 
The problem with singers singing "EEEE" is back on some recordings at loud volumes using the mkVI filter.

I'll try and solve it with woofer mods, and box improvements.
 
The "EEEE" problem was caused by earwax...

I built these speakers with stuffed ears it seems, now that they have been cleaned out, it's all good.

Bass down to 60Hz, minor peaks above 2KHz, but not around the crossover point, no issues with the filter.

Still room for improvement I'm sure, but I'm satisfied right now.
 
I thought I'd add this graph here as well.
It's the Vissokogovoriteli VKN12211 4ohm (same as the GAMMA BK3013A and LA1231).

e901be6a_LA1231freq.png
 
Soon to be in my possession, a complete and unused GAMMA 3-way kit incl. crossover networks at a bargain price (for GAMMA 50, 70, 100 speakers)
I'll only need the BK3013A's and VLD-12's, still it's a bargain!

This is a very very rare sight indeed! :drool:

e278-3050-43e4-b343-9f3dcb92c1b8.jpg
 
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Vissokogovoriteli/GAMMA BK3013A/LA1231/VKN12311 bass response in 50-60 liter sealed box, as simulated by WinISD Pro

25909d8c_AS55L.png
 
The final build will probably look like this.
A 100 liter sealed box, horizontal driver alignment:

87624e9c_GammaNLP100.jpeg


It is a box made for a GAMMA 100 speaker, the final product will be designated "GAMMA NLP100" where NLP is an acronym for 'No Low-Pass'.
 
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No no no no no, I'll use my 50 liter boxes, increase the volume to ~60 liters, by mountingthe baffle on the edges, stuff them well and put two Scanspeak flow resistors in each box.

Those 100 liter boxes are too heavy to carry, and have a huge foot print, I don't think I'll have enough room, they are very tempting though.

Edit: The 60 liter aperiodic boxes warrant a another designation, the GAMMA NLP-60A (A for Aperiodic).
 
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