Is it a Waveguide or is it a Horn? Plus Phase Plug Experiments 

If you have the capability to equalise then the best by far approach is to make the on and off axis response the same giving a good power response that can now be manipulated however you want. Pro audio went down this path decades ago and now just laughs at the HiFi worlds half arsed attempts to get good room response. So learn some maths, design your horn to be constant directivity and accept the topend rolloff on axis and then equalise. All your little manufacturing fun can then be directed at reducing throat distortion and getting the directivity to match throughout the complete response for all drivers in the system.

You need to fix the shape of the horn, not add a phase plug...

Best place I know to hang out, have fun while learning - and not be sold a time share.

EQ can definitely do that if you overuse it (I have in the past) and don't look at everything it affects (I've done that too...). But it's a tool like any other that can fine tune to get the results you want. Much better if you can do that on an individual driver level, rather than globally, and limit how aggressively you use it. Having a digital crossover with PEQ filters for each driver is a true luxury and makes the passive crossover option seem stone age in comparison.

That's what it's become, for sure.

I'm not saying you're wrong...but how you say it is entertaining! I like good sound, but I have a deep distrust in "hifi".

Unless your a bat and can hear the microwaves !

@@kfl611 Not one bat in the ntire world hears above ultrasonic.

@@JosephLorentzen Of course ! Just saying. Animals are amazing in how wonderfully they perceive the world and their environment.

All true for untreated rooms, but off axis response (and reflections) are less important in an acoustically treated room. The room these are in is treated and that's why the 1/24th response is so clean without gating.

@@Audio_Simon I was going to try a disk after the bullet, and then got sidetracked on the foam. And before I knew it the day was consumed. I think that while doing these experiments was interesting, the net gain isn't worth the effort. Most people won't hear the reduction in output at 17Khz, so it's just for the "flat to 20k" bragging rights that it has any value.

There's not a lot of content beyond 15khz in most music, so that makes the gains even less. But with that said, I will try a disk and see how it performs. Easy enough to try it while I'm doing the final setup on the speakers.

@@IBuildIt I'll look forward to hearing how it works out. I'm someone who found significant benefit adding supertweeters with a 16khz 24LR acoustic filter to a speaker with Neo3 planar tweeter so we obviously hear quite different.

Well, often the difference (not necessarily improvement) that guys hear when they add a super tweeter is the comb filtering that happens when two drivers are cancelling each other out at certain frequencies. Unless the super tweeter is extremely close to the tweeter physically or there is no overlap at at all with the tweeter in the frequencies it plays, comb filtering is a given. If you take a piece of music you like and open it in a program like Audacity, you can see how much high frequency content there is and at what level. Also normal hearing is most sensitive in the 2khz to 5khz range, and less so at low and high frequency.

@@IBuildIt My thinking is that the main audible effect was from changing the power response of the system. Much like a rear or upward firing tweeter, helping add back some of the HF reflections that provide cues for 'spaciousness' that get easily absorbed in room or simply don't exist from a narrow directivity tweeter. It certainly made the in-room response at listening position more linear, because without it the in-room response dropped off rapidly above 15khz or so. Given that you said you can not hear the top frequencies it would be a really interesting experiment to see if you hear any effect adding a dedicated 'super' tweeter that you could easily switch on and off, perhaps with a bit of dsp for easy tweaking. Just an idea for an interesting video!

In my listening room. It's the best place I have it, other than trying to set it up outdoors (and I'm not doing that).

@@IBuildIt by those measurements it seems like a hell of a listening room! How far away was the mic?

30 inches for everything shown in this video. When I properly set up the speakers I'll move out to a full meter away, but it won't look much different. In case you missed it, there are several videos here showing what I did in the room, along with measurements.

@@IBuildIt awesome, good to know! Thanks!

Are you talking about putting a 45 on the outside edges of the baffle?

He measures from that distance to reduce the variables from vibration in the room. Its not rocket science.

@@KipdoesStuff I know exactly why he measures from close up. You obviously have not been reading the replies, in depth. The point here... is that a Horn (or "Wave Guide"), alters the way that the soundwaves are projected. This could theoretically cause the waves shape, to become inverted, as it hits the guide, and or as it travels through the air. Thus, if you recorded two instruments in a room, using a Bineural microphone... and played this recording back on this wildly altered tweeter... it could end up causing the 3D audio positions of each instrument... into different places in the room. It might flatten the very depth of the image. It might partially or fully invert the image, depending on how far away you are from the driver. But what it wont be... is Accurate to the Recorded Image. You could then put on a pair of high end Audiophile grade headphones, and easily tell the difference in the 3d soundstage / image... from the poor quality speakers / drivers. Here is another thing that many Audio-Measurement freaks do not seem to understand... From my own personal experience, when listening to different kinds of tweeters: 1) While Ribbon Tweeters may have incredible accuracy... they have a very NARROW soundstage / sweet spot. Most of these high end speakers will sound so much worse, once you move a mere foot out from the center of them. Why is this? Its likely due to the fact that the drivers tape, is actually facing 90 degrees to the listener. This causes image distortions right from the very start. 2) Many Dome tweeters, are often too soft, and get ate up when there is heavy bass playing in the music track. Most especially at higher volume levels. 3) The most 3d sounding tweeter I had heard, was a dual pole ribbon tweeter, that had two vertical 1" tall ribbons... that were full 360 degree circles, mounted next to each other. These sat directly on top of small bookshelf speakers, allowing full 360 degree projection. The problem? Because the sound was being output in every direction at the same time... the sounds would end up bouncing off the back walls, and other areas... and arriving at your ears at different timings. It was making ECHO like effects... and completely ruined the intended Image of the recorded music and movies that were playing on them. 4) The best Tweeters Ive every heard... are from the EPI 100v speakers. They have the same concave shape that larger drivers have. They project an incredibly wide 3d image / sweet spot. You can move almost 90 degrees to one of the speakers, and still be getting an incredible 3d stereo image. Not only that.. but they vanish.. as if they are not coming from a speaker at all. Its like the instruments are actually producing the sounds in the room... exactly where the musicians were recorded. If I put a blind-fold on you... you likely could not find the speakers, even with a solid 10 min of searching. Now, Im not saying that Ive heard it all. Not even close. What I am saying... is that there is a LOT more to these "Measurements" than people realize. I can put two speakers with virtually identical readings / specs in front of you... and each will sound completely different, when you do an A to B comparison. Its not that one could not manage to figure out the best and most accurate ways to measure speakers. Its that the people whom think they are Experts in this field... are far more clueless than they even realize. And worse yet... they are so EGO bound, that they are not willing to even take the time to understand what the issues are.

@@KipdoesStuff Part 2: Im going to add one more point. While these dudes that make Measurements are so gung ho about "The SCIENCE"... They completely IGNORE the science behind what makes high end DRIVERS so much different from low spec drivers. For example... If you have a weak magnet, and weak driver coils... as well as a heavier cone material... you will get distortions. Why? Its pure Physics. If I tell you to hop in a Pickup Truck... accelerate to 60 mph in two seconds... then STOP in less than 2 seconds... can your truck do it? Nope. The "Driver" (Engine) is not powerful enough to be able to accelerate that fast. And the Brakes are not powerful enough to STOP the truck that fast. Now, imagine a speakers cone. The Musical wave, expects a lightning fast acceleration in one direction... and then within a fraction of a second later.. it expects to both stop and accelerate in the Opposite direction... at the same blinding fast acceleration rate. If your magnet and coils are not powerful enough... they cant get the cone to accelerate as fast as the music intended. And likewise... the driver can not stop and accelerate in the opposite direction, without some delays from the over-shoot... because its not powerful enough to stop it instantly. That is Compounded by a heavier cone mass... rather than a lightweight composite cone material. That said... if the cone material is too light and flexible.. it will distort due to the very air pressure, as it moves. These types of things are not brought up by many amateur speaker builders. They simply grab some fairly cheap Chinese drivers off of parts express, and call it a day. Many of these drivers might not even be made without flaws to begin with. Some may not have been measured correctly from the factory supplied Data-Sheets. Some may not match each other as a pair (in spec values, and in sound production). And just tossing a Poor, under-powered, highly distorting Driver into a fancy box, with an AWESOME EQ / Crossover... isnt going to make them sound spectacular. Is not going to make them "Audiophile" grade in experience / output / performance. Mariah Carey, I believe has an 8 Octave vocal range. You cant take a Paula Abdul vocal box (driver), and expect to get Mariah Careys level of sounds out of it. Not even with a lot of digital EQ and Effects. Just like you cant expect to race your Toyota Camry, against an F1 race car. There are huge reasons why these things are so vastly different in performance.

@@johndough8115 Have you designed, built and measured speakers before?

@@IBuildIt Part 1 - I have built one set, and modified others. My first one, was to take a PC speaker that had a horribly designed plastic shell + a poor pizero tweeter and flaky amp, apart. I cut some MDF strips, and made a general box shape... moving the loose panels around, to form different sizes, while the woofer was playing. I was surprised to discover, that the driver sounded Much better than the original enclosure. And my first lesson was learning that they sounded best with an open baffle... rather than when I tried placing a backing block on them. Finding the shape of the box that sounded best... I then marked, cut, and glued it in place. Then made the front panel to hold the driver and assembled it. Next up, I took a tweeter from a larger home speaker box, and placed it on top of the speaker, facing the ceiling. My idea was to make the tweeter fire up into a cone, to spread the sound in 360 degrees. Temporarily, since I didnt have the Cone that I needed... I cut a few wooden dowels "Legs", about 3.5" in length... and placed them on top of the speaker box.. at the four corners. I then set a piece of MDF on top of them. I was pleasantly surprised at how good they sounded. A huge upgrade from originals tweeter... and much better bass sound, than the originals farty fake-bass (tuned port) design. I initially didnt thing the tweeters were going to be powerful enough to spread out without the cone... but it worked so well, that I just decided to use them as they were. These were then wired to a box that I put two 12" woofers inside of a larger box that was under my bed. The reason, was due to me not having the space for the two larger house speakers on either side of my PC desk. And the fact that I really didnt care that much about that spare house speakers sound. The entire setups was actually pretty good. I placed the smaller boxes closer to the ceiling, on the top shelf of the desks hutch. They blended in decently with the 12" woofer box, and I was getting much better imaging, because the tweeters were no longer blocked from being under a desk. From this build, and a few other speaker mods...I quickly realized, how little I knew about the subject.

The formula I used for the horn was "this curve looks okay" :) But yeah, interesting idea! a horn within a horn!

@@IBuildIt within a horn, within a horn, within a horn...

You have to loosen your necktie!

@@IBuildIt Better drivers = Better sound. You cant soup up a Gremlin / Yugo , and expect Ferrari / Lamborghini / F1 results. A race car, has so many special attributes, that give it massive performance advantages, such that no standard vehicle can come close to matching them. Stiffer Frame - to prevent twisting under cornering stresses Superior and Stiffer suspension High power, specially tuned, and super-charged motor High power fuel pump, to get far more gas to the engine, much quicker Programmed Computer, balancing fuel mixture, to gear/RPM for best possible performance Special tires. Wider, and Tackier grip, to stick to the road at high speeds Lower center of gravity precision balance in weight, spread equally across all tires lighter weight parts, and reduced overall weight, for better acceleration and performance special aerodynamics, special cooling channels, and Downforce spoilers special engine cooling enhancements extremely powerful, heavy duty, brake mechanisms While people can have fun running a standard or tweaked car on a race-track... you can not really compare this experience, to driving a specially engineered "Super-Car". Faster acceleration, Faster top speed, superior stopping / braking, superior cornering at high speed, superior traction and responsive control... even in the worst case scenarios. Obviously, not everyone can afford a high end racing car. Many cant even afford to Hop up a used mid-tier sports car. But there are high performance speaker drivers, that are still very affordable, to even the modest of budgets. (much cheaper, of course, than buying an over-priced high end speaker that has been built by a company)

Scanspeak D2905

@@IBuildIt And? This is a textile membrane tweeter. It's heavy by default. It was born with significant slope (with an artificial bump at 12kHz to extend a range to 20). This is cheaty tweeter with a loud label. When you increased an acoustic resistance with the horn, textile gave up.

I wonder what would happen if someone tied both of you together by your tails and draped you over a clothesline... Now that would be wild and crazy, I think!