GoodSoundClub - Romy the Cat's Audio Site

08-26-2015

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Gargoyle
Posts 69
Joined on 02-01-2015

Post #:	1
Post ID:	21916
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Garg wants more horns.

This will be yet another log on building a maconalds inspired speaker conglomerates.

So far what I gather is I need to first sort out a upperbass/mid frequency combination before I dive into the rest of the details.

I too, will try to provide pretty sketchup pictures as I progress.

As far as amplifiers, I will probably build some dedicated amps as required.

I don't really have a budget per se, but this seems like it will be an on going journey which will make it easier to produce somewhat premium (to me) active devices. That being said, my purchases will probably considered frugal amougst this company, I won't be spending 10K or 20K on them.
As far as the horns and rigging etc, I would like to build those myself where possible.

I am a neophyte when it comes to fully horn loaded systems. It is the next logical step in my audio journey.
Currently I am content running some 604E in some 16 square foot reflex cabinets I made with some pretty decent 1 watt direct coupled amps, so I do not think I am completely retarded, time will tell however.

Stay tuned.

08-01-2024

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Gargoyle
Posts 69
Joined on 02-01-2015

Post #:	2
Post ID:	27439
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...and we're back.

Starting at the top. I have some HF drivers on the way, so I thought I would make a few cones to try when they arrive. On top of paying too much for the convenience of amazon, I also unintentionally ordered mylar drivers instead of phenolic. Do I care? I don't know. I just want to build something without the usual hifi angst over parts selection, especially ones that are nostalgic in others eyes.

I have parted out my SETs and Altec speakers. Tonight I am listening to a pair of monoprice monitors with only one tweeter. It can get lower than this, but not much.

The DE10 tweeters will need to be run above 2-2.5Khz. These are 884Hz tractrix horns. I figured it was as good of place to start as any. ChatGPT gave somewhat conflicting information on a somewhat ideal horn size for this driver depending on what it thinks you are asking for. Perhaps more nuanced than I give it credit for at times.

In order to facilitate experimentation, I purchased a pair of generic pro audio style 234XL 4-way crossovers. I actually like the rack mount style but will be soldering past the XLR connectors. I was tempted to DIY some ESP or Marchand active units, I even hoped that these would be through hole electronics should I desire to upgrade components. However it did not make sense cost wise, considering these are in cases and have power supplies. About $100 Canadian each.

Eventually I will build some little tube amps again, for the time being I will be focusing on building the speakers and using class D. I have three TPA3255 amplifiers to use as stand ins. I don't really have a fourth amp in mind or anything more suitable than another D amp, would probably start building tube at that point.
I also bought a USB mic (Umik-1) to use with REW, no matter what you buy it is always wrong. Using this particular mic for time alignment is convoluted. Again, lets not fuckin obsess over every purchase, just I really thought I knew what I was buying, as say compared to a speaker DATS or a mic and computer interface etc. Regardless I am looking forward to actually doing some in room measurements which should be cool.

08-03-2024

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Gargoyle
Posts 69
Joined on 02-01-2015

Post #:	3
Post ID:	27444
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615Hz Horns on the plate.

I am currently printing the "large" horn today, to explore running the DE10 driver below 2500Hz, maybe around the 1500Hz. EDIT:I will make the cone but 1500Hz is too close to impedance peak.
These are tractrix as well.

I would also like to take the opportunity to label this project/these speaker(s) as "Airship(s)" ™
Originally these DE10 were chosen as the highest channel, although there is the possibility it could be used in a second position, as to not cover too many octaves
This driver does roll off a bit at he top end. Not a huge concern as long as it sounds nice up to that point.

Tonight I think I will design the "small" cone. When the drivers arrive I will set them up as a 1-way or 2-way with a 6.5" dynamic driver and use them for daily listening.
(This system will be used for everything) This way I can get to know the driver intimately. and choose the cone that sounds nice, (least sibilant, smooth) then go from there.
It's an individualistic approach as it is obviously not practical for me to choose the devices based as a whole package. I don't think it is a problem.

08-03-2024

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Gargoyle
Posts 69
Joined on 02-01-2015

Post #:	4
Post ID:	27445
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Full audio retard

If she had been a well-brought-up little girl she would have waited till the Bears came home, and then, perhaps, they would have asked her to breakfast; for they were good Bears—a little rough or so, as the manner of Bears is, but for all that very good-natured and hospitable. But she was an impudent, rude little girl, and so she set about helping herself.

1250Hz

While smitten with my robotic slaves, I've obviousness contemplated the construction of the larger horns. I've recently built a cnc plasma cutter, which is essentially a 1m square printer if I swap the tool head. The biggest difference being lack of a 1m square heat bed, which would probably nice to use. (Perhaps not necessary though)
That being said, I have a 12"x12" aluminum tool plate and 750watt heater which would be big enough to stick a horn to if printing in the same vertical throat-down orientation that I am now. Big printer small bed, the mouth overhangs the bed.
I probably don't quite want to fuck around quite that much, on the other hand, come on. Do I build a machine for a personal project vs just make the horns in segments? 50:50. The third thing will be, do I want the luxary of trying multiple horns like I am now whit the small one cones.

08-04-2024

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Gargoyle
Posts 69
Joined on 02-01-2015

Post #:	5
Post ID:	27447
Reply to:	27445

Now the window was open,

because the Bears, like good, tidy Bears, as they were, always opened their bedchamber window when they got up in the morning. So naughty, frightened little Goldilocks jumped; and whether she broke her neck in the fall, or ran into the wood and was lost there, or found her way out of the wood and got whipped for being a bad girl and playing truant, no one can say.

08-05-2024

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Romy the Cat

Boston, MA
Posts 10,173
Joined on 05-28-2004

Post #:	6
Post ID:	27448
Reply to:	27439

This is very funny and VERY loaded.

Gargoyle wrote:
ChatGPT gave somewhat conflicting information on a somewhat ideal horn size for this driver depending on what it thinks you are asking for. Perhaps more nuanced than I give it credit for at times.

"I wish I could score everything for horns." - Richard Wagner. "Our writing equipment takes part in the forming of our thoughts." - Friedrich Nietzsche

08-05-2024

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Gargoyle
Posts 69
Joined on 02-01-2015

Post #:	7
Post ID:	27451
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Listen to the ocean

I spent some time today listening, by holding the shells up to my ears, so to speak. Something we should all relate too. They all have their "ambiance" or static voice. The large horn sounding like an offshore ocean breeze, I swear I heard a coconut fall, the smallest horn hissing like a 1980s cassette.

Thinking of horns in reverse, it yields some interesting anecdotes by hearing the horns alone, with their towels down.

To expand further, the textured surface idea has been driven around here before, so let's play.
A duplicate of the 1250Hz horn was made but with some shark-skin like texture.
There is an obvious difference listening to the sharkskin horn vs the "smooth" horn. (The smooth horn was scuffed up to remove surface defects but still retains some layer lines from printing, it is not truly smooth)

I have to listen to quiet things to discern differences, like a background computer fan or some digital hash coming through my speakers from the computer.
The best that I can tell from my ear is that the textured horn has a lower frequency "ambience". Sometimes seemed quieter but not always, so I attributed that to how I was holding the horn.

Now I printed an adapter to see if I can measure something that might correspond to what I am hearing. Lets have a look at my dubious test.
Three sweeps of each horn overly. RED, GREEN and BLUE are the textured horn, the other colours are the "smooth" cone. Keep in mind likely huge margarine of error. This test was at 75db but as I type this I think I should have went much quieter like my listening test.

So it might look the opposite of what I heard? The frequency response seems somewhat similar?, or is it actually a bit lower if equalized for sound level? The textured cone appears to pick up more information? Maybe it is doing it's job to diffuse the sound and what I am seeing is the result of mechanical vibration directly to the microphone from this interaction?

Should I be like DIYer and call these cold hard facts, or be more measured and perform the test again? Is this too many questions?
***The first green from the textured cone is burried with red and blue. The lower lighter green that you mostly see was the last sweep with the smooth cone, so it is more visable.

08-05-2024

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Gargoyle
Posts 69
Joined on 02-01-2015

Post #:	8
Post ID:	27453
Reply to:	27451

60db Redo

RED=Smooth cone
GREEN=Textured cone.

This test was done at 60db, the background noise was around 56db. This seems to agree with the last test, the textured horn is more sensitive across the whole band. Almost 1db louder at 8K.
This is a result, but what is the interpretation? Does this backup or refute the claim that textured surfaces make for a "quieter" horn?
I think the increase in sensitivity could be interpreted as a quieter horn, as it is absorbing more energy.

08-06-2024

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rowuk

Germany
Posts 454
Joined on 07-05-2012

Post #:	9
Post ID:	27455
Reply to:	27453

In german we have a saying "wer misst, misst Mist"

I am ALWAYS critical of sweeps that are "essentially" parallel - especially when smoothed beyond recognition AND when assuming correlation to an audible trait. "Absorbing energy" or "quieter" does not mean louder, rather the opposite. I would say that your pretty picture tells us nothing about anything except that a single, well chosen capacitor could flatten out what we see. Further questions:
1) signal only 4dB above the noise (60dB vs 56 dB)
2) no polar plot
3) no spectral analysis (to show noise/distortion/decay)
4) no indication if this tweeter can be integrated to anything else.

Gargoyle wrote:

RED=Smooth cone
GREEN=Textured cone.

This test was done at 60db, the background noise was around 56db. This seems to agree with the last test, the textured horn is more sensitive across the whole band. Almost 1db louder at 8K.
This is a result, but what is the interpretation? Does this backup or refute the claim that textured surfaces make for a "quieter" horn?
I think the increase in sensitivity could be interpreted as a quieter horn, as it is absorbing more energy.

Whenever I feel blue, I start breathing again.

08-06-2024

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Gargoyle
Posts 69
Joined on 02-01-2015

Post #:	10
Post ID:	27457
Reply to:	27455

Du Karussellbremser

The actual tweeters have not arrived yet, tomorrow. This is one channel of a rather miss-configured bookshelf speaker. The first sweeps above were 75db.

Now you know this is a microphone inside a horn, not a typical external sweep of the horn. The shape of the sweep is arbitrary.

The textured horn picked up more noise. (Assuming this is accurate.) I have a 50:50 chance of being right. The horns are not the same, one is louder. (colored) The smooth horn sounds louder to my ear. I have not really postulated an audible trait. It's safer to allude.
The denticles on the textured horn give it more surface area, it's done something. In my naive opinion that is fairly significant difference given the low sound level.

Which one do you think it is louder? To clarify, I'm talking about coloration from the horn, that "ocean" sound. Not louder horn db.

Does a bell not ring when you strike it? What do you think would happen if you decouple the compression driver from the horn to remove the mechanical excitement?
Perhaps another topic.

This is how you understand things. I will teach you great things.

As cool as it is it look at atoms, I'm was more interested in a tangible, easily achievable results first. I'm still in orbit around this project.

I can pretty much disregard the rest of your deficiency list for now as it is not relevant to this specific situation. I will however make note.

08-08-2024

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Gargoyle
Posts 69
Joined on 02-01-2015

Post #:	11
Post ID:	27461
Reply to:	27457

Grabbed the reins.

Tonight I had to get this temporary 2-way setup right as this project is being used everyday while it's being built.

I wired the 6.5" box speaker to a lower channel. I was worried that, missing bass aside, everything sounded like shit. The muscles in my ears were doing that spasm thing. I was worried the 234XL units would not be usable for their temporary role of getting the airships built. They seem fine now.

I swapped around the three different horn sizes, essentially in real time, by holding them up to the driver. For sure the biggest 615Hz horn is the way to go out of the three that I made, It has everything of the smaller horns without losing anything (At least to my quick ear tests) It seems the most versatile.

The little 1250Hz horn was cool, pretty transparent if you just wanted to use it in a higher/highest freq application. However I'm taking more mid-range from these drivers, in fact I could put another tweeter on top of the big 615Hz horn if I felt I needed some sizzle.

It's cool using the active crossover. I started with the big horn at 1.4K, just to get down close to the 6.5" woofer. Turning the dial up to 2.4K the horn then disappears into the background leaving behind just the music. Really cool to hear it happen like that. These drivers/horns sound good with a bit of room to swing their feet.

That being said I now have bit of a hole in my response.. (6.5" are below 960Hz)
Doing my best to recall the 604E speakers that I had, I can now sense some congestion. I think it was crossed at around 1500Hz, IMO a bit too low for the little multi-cell horns that they have.

The speed of the horns took a few songs to get used to again, it's been a while.
The little woofers are sealed however with foam surrounds, obviously a little cotton mouthed in comparison.

As far as the actual B&C DE10 compression drivers with the mylar membranes? They have a gentle presentation, I am not disappointed. A simple cliche description would be organic sounding. I was worried I would get a piezo-electronic sound. I have no other reference other than to say I like them better than the Altec that I had. Self bias aside.
They are creamier than the little ribbons that they just replaced too. I like them.

08-08-2024

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Gargoyle
Posts 69
Joined on 02-01-2015

Post #:	12
Post ID:	27462
Reply to:	27461

Tilt-a-whirl

I get the whole don't toe in the speaker thing now. Like most people I have always pointed the speakers directly at myself, studio monitor style even with floor standers.

These speakers tonight sound better shooting straight out. It feels weird to look at but sounds better. I'm sitting what feels really close too, the speakers are 4.5 apart and I'm sitting 3' out.

If I toe them in I loose something in the mids, the "extra detail" feels unwanted and somewhat raw in comparison. I've never really sat down and done this comparison.

See that's why this site is great, Romy notices and retains little audio nuggets like this. Otherwise this detail seems so small that you would typical ignore it.

08-10-2024

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Gargoyle
Posts 69
Joined on 02-01-2015

Post #:	13
Post ID:	27469
Reply to:	27462

Fuzzed up

I made a "fuzzy" 615Hz cone to compare against the smooth 615Hz cone. (These are measurements of the DE10 driver.)

RED = Smooth
GREEN = Textured.
1/3rd smoothing. Around 65db room temperature test.

The textured horn seems to be quieter, as predicted.

As far as audible traits, I haven't listened. I just got the drivers the other day, so my audio memories of this system have not been established.

There are however visual differences in output of up to a db. It was not hard to measure or repeat.

If I had to choose one based off this graph, I would choose the GREEN fuzzy cone, because it appears to be a bit smoother.

I'm going to try and get a distortion measurement next to look for potential differences in character.

08-10-2024

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Gargoyle
Posts 69
Joined on 02-01-2015

Post #:	14
Post ID:	27471
Reply to:	27469

Anecdoodles

At my current, moderate sound level I did't see anything within the distortion measurements that stands out, not that I particularly know what I am doing. (Decay, waterfall, spectrogram)

I was however interested in seeing the behaviour of the three horn sizes compared to each other:

green = small 1250Hz horn
blue = medium 884Hz horn
orange = large 615Hz horn

To quote myself from earlier, the larger horn didn't seem to lose anything to the smaller horns. This seems to correlate.

08-12-2024

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Gargoyle
Posts 69
Joined on 02-01-2015

Post #:	15
Post ID:	27488
Reply to:	27471

Switcheroni

I have made an attempt to coarsely align these speakers.

There was a technique I that read said to reverse the polarity of the tweeter, then play a sinus at the Xover freq then listen for nulls. This sounds like a good idea but did not work out for me in reality. It may work if you had a second person and a adjustable track to put the twitter on. My free-hand attempts were hit and miss. I was too close.

As an alternative I measured the magnets, they are both 15mm thick so i just lined them up. This assumes the voice coils are in the same position in relation to the magnet, which they likely aren't.
Then I set the speaker box on it's side, mounted the tweeter on top, so that it was closer to the woofer. I actually did not mind this sound for better or worse, however I ended up completely flipping them upside down to get the drivers away from the surface of the desk. The desk is a temporary home so the situational improvements in that regard are somewhat ignored.

In hindsight I should have mounted the tweeter closer to the woofer before I tried that nulling technique. It would however still need a adjustment track. It seems like the ability to align needs to be in the final speaker so I will try to incorporate it into the mounting of the horn. The plan and assumption is that I can use this umik and REW to align, but not much point right now if it's just tape to fix the position.
I'm starting to think about mounting solution for the horns as I'm going to get another channel soon. I don't want to use masking tape and a broom for that. I could make clamps for some round metal electrical conduit, or maybe just a piece of wood to screw the mounts too. While it is premature to commit to a design I could go with something if it was modular enough. A metal pole seems pretty modular although not very aesthetic.

08-21-2024

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Gargoyle
Posts 69
Joined on 02-01-2015

Post #:	16
Post ID:	27541
Reply to:	27488

Sometimes

I wish I could rename this thread. Who is this third person who applies a nick name to their own avatar. It sounds fuckin retarded.
However to rename it now it would lose it's original fidelity, like some cringey and irrelevant 90s gas station remaster

The robot was instructed to commence the first iteration of a 5-piece 375hz tractrix hoen. These will have the deep fried texture, based upon the extent of my test and the lasyness of my assumptions. It will be interesting looking at the behaviour of textures on the lower freqs, don't get me wrong. For the time being I will focus efforts on evolving shapes instead of textures.

In theory there are a few different ways to assemble these horns, epoxy, zip ties etc. The first version will have M5 hardware, the idea being I can swap around parts like for the inevitable throat adapter swap depending which driver I ultimately choose. Thinking about the weight of the hardware on the ribs may help with damping. Maybe worse.

08-23-2024

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Gargoyle
Posts 69
Joined on 02-01-2015

Post #:	17
Post ID:	27550
Reply to:	27541

Back to smooth for now

I ran into some stability issues the other night, it failed about 80% through due to stability issues. I knew it was quite a risk but I generally like to avoid support so I keep that in mind when designing and orienting the print.

Since I've added a bit of support I've removed the texture to save on time. (Texture almost doubles the time) The texture would have also caused some minor annoyances with the captive nuts and hardware clearances are guesstimated.
Hopefully be then the software would be updated a bit, it has the option to add texture to all walls or outside walls, the problem is these pieces of horn do not have inside or out. For the small horns I would like the option for "inside" only which is oddly missing. They have a good paint on feature for the support that would be good if they could combine that with the fuzz.

If the shape was simpler I could put some interfering shape that would block the texture, but the horn is too curved and thin it would be difficult. I just print it along the long side now with a bit of support and no texture to save a bit of time, as these first ones are just temporary.

Really I should consider the attachment point for mounting as those would likely take a few attempts to settle on something

08-23-2024

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Gargoyle
Posts 69
Joined on 02-01-2015

Post #:	18
Post ID:	27553
Reply to:	27550

Zip ties

are an option for assembly. Aside from the obvious ease of use, I was considering the joint behaviour, really just looking for problems. It occurred to me the potential advantage of having a less-than-mechanically tight joint. Zip ties and a somewhat conformal gasket could do that. (Or something similar, could be just thick silicone etc. to do both)

The five individual horn pieces having higher self resonance semi-coupled creates some opportunity to push the resonance of a horn one way or the other. I'm not going to try and guess something like that at this stage or whether good or bad. I'm not anticipating a specific resonance problem yet but as the horns get bigger this could be a way to react rather than adding weight or stiffening. Fracturing the resonance into different regions. Like a fractured egg held together with that thin inner skin.

There is also the chance that the shape and density of the infill, in addition to wall thickness could do similar things, I'm getting a bit into the weeds.
These bigger pieces are starting to feel like something resembling pressed cardboard or hard paper mache. Kinda has that sound when you tap or handle it.

This 375hz chalice I want to run from 1000hz-1500hz up to 2400hz-2500hz

08-25-2024

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Gargoyle
Posts 69
Joined on 02-01-2015

Post #:	19
Post ID:	27561
Reply to:	27553

Full quarter

Functionally speaking I think the printer will be OK for this size of horn. I would thicken up the walls a little bit like the smaller horns, this will make the exterior flare not quite as steep, so that I can print the parts vertically. This would produce a bit nicer joint, as the seam is slightly effected with the piece printed on the side.

Last night I found a thread on here that shows an almost identical horn, conceptually. I don't know if he built it or not but would like to acknowledge that I have seen it and the similarity. Perhaps I have seen it before, perhaps it's just a default thought. (Jessie Dazzel)

Now I am going to look at the next size up, it should still be reasonable practical.