Powered speakers show audiophiles are confused

The one wave guide I have personal experience that clearly stands up and salutes is the one JBL developed for the M2. After that development they started trickling it down to their other speakers. I think it is amazing and here is Frank Filipetti breaking it down (1:15). If you check out Frank’s discography and sample his mixes the "proof" is in the result IMO:

@donavabdear ,

For you Genelec, the mid is the waveguide for the tweeter and the front is the waveguide for the mid, so we better hope things have gotten better.

Reflections, higher order modes, throat and mouth and edge diffraction, resonances, it is not as easy as it seems.

The answer is the problem still exists, but we have gotten much better at making them, not the least because we have software now (even in the DIY community) that really helps to automate and optimize aspects of the designs so instead of making a 100 revisions or more CNCing plastic, you are now making 5-10 and printing them. How many you need usually comes down to how good your model is of the underlying driver.

Our software like our competitors is a mix of proprietary software and off the shelf generic tools and plug-ins. Obviously can't post that, but I can post stuff out in the "community" that is really good. This reminded me of a interview with Earl Geddes, always as crotchety as ever, but also always interesting. I like the guy, don't get me wrong, but he is like that friend you have that is always cranky :-)

The video is rather apropos, as he mentions active and passive speakers too, though I consider some of this comments outdated. Some however, are not. The most important one is that active speaker design does not magically solve all issues. You need to start first by being a good "passive" or in essence fundamental speaker designer.

https://www.youtube.com/watch?v=nhe8VfuTg08

More relevant to the discussion is his mention of what he considers, and many agree, of the importance of constant directivity to ensure a speaker sounds good in most environments. This is a implementation embodiment of the Toole\Harman research showing smooth off-axis response is important. That does not solve the waveguide issue, it just give credence to why it is important to solve it. Very relevant to the discussion is the use of software for wave guide design. Geddes says that even the DIY S/W, or at least semi open source, does a better job than he was able to do. The software and a comprehensive discussion happened here:

https://www.diyaudio.com/community/threads/acoustic-horn-design-the-easy-way-ath4.338806/

@thespeakerdude Great, thank you for that. What is a problem is longer wave guides or horns or anything that is trying to direct the wave. Call 1k a 1 foot long wave (close enough) 2k is 6 inches 4k is 3, at this point horns and curved boxes with computer curves easily confuse the wave by bouncing them in and around whatever kind of guide the designer has made, there is no way out of that sinareo. Horns are never ok, they may sound good but the huge difference in size of waves doesn’t allow a horn to accommodate multiple frequencies properly. A traditional cone driver is simply a piston that creates the wave but doesn’t redirect it, (except for the edges and things like that) as horns do. My Genelecs use the term wave guide but it’s really wave takeoff more than anything because the size of the waves and the depth of the high frequency and mid frequency voice coil throw is so much shorter, they aren’t designed to guide the frequencies like the Tannoy and the Uri’s of the past which sounded like everything was pumped through a bullhorn, even a multi million dollar showcases theater with an 80 inch sub has got this wrong IMO. The 80 inch driver is a perfect example, what would that horn have to look like well it’s impossible to make a horn that accommodates frequencies that large between 1 and 20Hz you would need 20 huge horns. In that video they described midrange center channels that used a curve to redirect the waves to the audience, this is a big compromise in a no compromise room. A great Director of photography I worked in the movies always spoke of the light he used as "them" he would always bounce, diffuse, cut and all the other things DPs do with light by thinking of light as little particles that bounces around, so I told him use one of my sound diffusers to bounce his light it only makes sense, he was amazed he hadn’t ever seen that before. The moral of the story is if you think of the sound as particles that interact with each other you would never expect to send them down a horn and expect to not have them interact. Hope that’s a tiny bit clear.

speaker dude wrote, "I won't speak for @donavabdear, but I will speak for myself that the question is essentially irrelevant and is begging an answer. Phase corrected is essential for any working speaker design, time corrected looks much better on a marketing sheet than providing verifiable listener benefits. And yes, I have personally done the testing. Dynamic correctness, dynamic excitement seem to be implying the same thing. How long can you play, and what effects of any concerning dynamic compression. Horn loading / compression drivers is not the only way to achieve this of course. Horns provide, properly designed, constant directivity, but using a standard woofer/mif-woofer and a wave guide tweeter provides similar benefits without the side effects of vertical directivity lobing which can cause unpleasant reflections off vertical surfaces, likely one of the reasons why some people "don't like horns".  I think we can agree that a real horn loaded speaker at 20Hz, even a tapped horn is rather enormous and outside the realistic realm for most people. To achieve true directivity at the frequency is just unrealistic and you are not going to avoid room modes. Velocity/position feedback eliminates power compression issues in subs, and cheap efficient amplification is plentiful. Just put in a bunch of power subs and be done with it."

I respectfully beg to differ.  My DIY speaker system uses Bill Fitzmaurice designed HT Tuba 25 Hz quarter wave folded corner horns.  The output at 25 HZ in my DEQX equalized system is identical to the output at the 1 kHz reference tone.  The output at 20 HZ is still audible and musically useful.  They are 18 cubic feet each but wearing a nice coat of Blonde Burmese teak veneer with solid teak and brass trim and tucked away in the corners where they need to be they don't seem particularly obtrusive to me. 

Including the horn path in the bass bin plus the distance out to the midrange horn which is well out into the room where it can image better makes the separation between the acoustic centers and the woofer and the AER BD3 midrange drivers over 16 feet.  The time correction provided by the DEQX DSP makes the acoustic centers of those drivers sound as though they are within 3 mm (less than 1/8 inch) of each other.  That is not in any way irrelevant.  If you have ever heard properly executed horn deep bass I think you would understand the difference between that and using a bunch of power subs and perhaps even learn what I mean by dynamic excitement.  I notice that Genelecs best subwoofer is already 6 dB down at 27 HZ.

My system is active using six channels of amplification. Contrary to donavabdears contention that audiophiles who don't use a bunch of little active cones and domes in a box are confused I respectfully beg to differ with him also.

@kingharold

They are 18 cubic feet each but wearing a nice coat of Blonde Burmese teak veneer with solid teak and brass trim and tucked away in the corners where they need to be they don’t seem particularly obtrusive to me.

Thanks for posting this, the pics you posted are stunning. Some of the wannabes in this thread are keyboard warriors who are simply posers. Your handle is certainly appropriate from what I see in your system profile, nice job.

I would like to know more about the deep horn loaded bass you describe. What type of space do you need, budget, etc. Thanks.