Discussion in 'Speakers' started by toddalin, Jan 27, 2019.
Hey Denny, I'll trade you straight across. My Soundesigns for your speakers.
Thanks Mike, I'll take that as a compliment.
I would truly love to hear them. I've had my Altecs so long I haven't heard their flaws for 20 years. Saved me a ton of money for sure.
Hey Dennis, are those Acoustic Elegance Lambda TD-15" woofers?
These are 30 and 60 degree angles at 1",1-1/4", 1-1/2", and 1-3/4". Doing up two sets allows for a much quicker comparison of angles and lengths and the tape is applied front and rear so they pretty much hold their shapes and just plug in. We'll see how this shakes out before going to individual vanes.
PS, Wife hates the smell of the burnt acrylic so these need to air out a couple days.
Test video. Heil is fed pink noise from the Behringer through a 13.3 mfd cap and in series with a 4-ohm Mills 12.5 watt resistor. This then forms a Butterworth first order high pass filter with a crossover frerquency of ~1,500 Hz. Next step is to make a 30 degree from acrylic rod. The wider wedges didn't seem to work as well as the smaller, but I only tried a couple at this point.
BTW, when people say that the ESS AMTs lack midrange, I think the video will demonstrate why this is, and I'm betting a pair of wedges would satisfy most.
Mic is on-axis at 2 meters.
Edit, I guess they don't make acrylic rod in that angle. I guess I could try to bend some metal, but it won't have the same finesse.
Toddalin: Thanks much for doing all this work and documenting it so well. I will work up some wedges and give it a try myself. In the past I have toyed with some rear deflectors out of scrap wood at a 45 degree angle but nothing in the front. Thanks again!
Sure are Dan. M model. They are great woofers with a lot of slam if needed as well as great detail not normally found in a 15 inch woofer.
Its interesting that Heil graphs show flat out to 30 or 40khz but you are showing pretty much dead by 16khz.
It's a fairly dead room, but no, they don't go as high as the JBL 2405/077 and you occasionally hear this difference in direct A/B comparisons. They are smoother in their range though.
Because I can't find what I want. I've designed my own wedges from acrylic plates that will be stacked to give the desired height. I have black, smoked, and clear acrylic and will do some form of pattern up the wedge.
The pieces will be bolted together as the Heil is. A screw will come from the top and pass through the wedges:
The bottom wedge will be cut to hold a 8/32" machine nut so that the ~27-32 pieces can be bolted together. These are actually 40.6 degrees to leave enough meat to fit the nut and keep the overall length to about 1.2". Longer pieces showed less effect.
The screw/stack will proceed further through the upper base that is slotted to allow the wedge to be adjusted. Note the cutout for the "Heil glue" so it can snug up to the Heil base.
This is glued to a lower base that will allow for a nut to be tightened with a small pliers.
I've also designed an "assembly bed" that has the same angle as the wedges that will hold them to assist in putting the pieces together and deciding on a color scheme. The bed is marked for the correct length making this much simpler.
For those who may want to try this, there is a fairly simple way to get a similar shape in the right size and length. Buy balsa wood "trailing edge" and glue two together in the proper shape and cut it and finish it. It needs to be ~5.45" long. It comes in 1-1/4" length. You can get it at hobby stores and online/ebay.
I believe that these are ~15 degree right angles so you would turn one around when gluing them to get a symetrical centerline. I would do it, but already have the acrylic. But if someone wanted to and let us know what they think, that would be great.
Now you've made me curious. I'm not sure that the >16kHz is anything that I can hear anyway but, ...
I happen to have 2405s, 077s, and Heils on the same switch. The difference to me is the speaker system, and I haven't been able to isolate anything that relates to "smoother" other than the Heil is crossed at 1kHz and the others are crossed at 7k/8k. In my case the crossover and mids have more influence on the sound of each system than the tweeter technology and each of my speaker systems has its own character.
Could it be the rest of your system as well? Maybe your Heil is running a custom crossover (active or passive) and has better characteristics because of that and other influence?
I like what you're doing, but am not able to find faults in the music from my Heils (objectively), am interested in what you hear.
My 2405s cross over at ~7,200 Hz. My Heils cross over at ~2,200Hz. Initially, they were up around 5kHz, but the mid (JBL 2251H 10") couldn't smoothly play that high to meet them.
Just as the Heil has it's dip at ~5-6KHz, so does the JBL but at ~8-9kHz. This then puts the JBL dip in the range of the upper cymbols, whereas the Heil puts it at the lower cymbols. So in the range above the Heil's dip, where it would be crossed over as a tweeter, it is smoother, at least to my ear/measurements.
Of course the 2405/077 is nowhere near as bad as the 2402/075 for this.
Something else to consider...
I did my measurements at ~2 meters. I don't know the distance that Heil used in their graphs (typically 1 meter, but who knows..., maybe even at the diaphragm?).
I do know that while sound overall attenuates at a rate of 3-6 dB per doubling of the distance (line source vs. point source), this is a general concept and the sound actually receives additional attenuation above this factor. The higher the frequency, the more quickly it attenuates from the previous calculations.
Interesting, my 2405s cross at 8kHz (from 2470/H92/L91), the 077s at 6.5kHz (from LE-5), and the Heils at 1kHz. The Heils seem to act more like an electrostat than electromagnetic driver to my ears, but I wasn't aware of a significant dip, at least not in my listening room, something to EQ out with a DSP perhaps?
Certainly an option if one chooses to use eq in the system.
Made these today. Tomorrow will cut ~70-80 wedgies with a round hole.
man does that look nice....
Done. Now for some listening.
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