DrWho

Jaaaaaag - haha, good times. That should definitely be on that list too.

Btw, whereabouts are you located? I'd love to run some comparison curves between the KD-15 and KD-16. Also, I just realized I have a spare KD-16 sitting around collecting dust. Only one of my passives broke, but the other is totally fine.

I remember @Chief bonehead mentioning something about early generation CF-4's sounding better than latter generations, but it's so long I may have that wrong. I also remember him saying something they were some of the smoothest sounding speakers ever. Unfortunately I've never had a chance to hear a pair.

How many of them are car enthusiasts? I'd imagine the car enthusiasts just don't end up buying them.... I consider Top Gear (the old Top Gear with Clarkson) to be one of the best representations for the car enthusiast. They have nothing but railed on Tesla from the very beginning. But it's not just Top Gear - I've not read a single review from anyone that enjoys driving for the sake of driving talk about it as being an excellent driving experience (yes I know, you can find car magazines that speak highly, but they're motivated by other things). The suspension rides horribly and makes you feel disconnected from the road, the brakes feel weak because the car ways a million pounds, the car rolls a ton despite its low CG (the much higher mass has the same effect as moving the CG higher when comparing against a lighter car). The seats are uncomfortable, most of the interior doesn't follow any ergonomic standard. You just feel disconnected from the road, but not in a comfortable luxurious way. Ya sure, it accelerates quick from a stop, but that gets boring after a while. It's just not confidence inspiring and you spend all your time analyzing if you have enough energy to arrive to your destination. It's just an incredibly unrelaxing experience....always making me nervous about everything. And if you do any spirited driving, then you gotta watch out for the braking system just deciding to turn off as you fight with all your might to keep the car from flying off the corner. The Model S can't even do one lap around a track like VIR before going into limp mode. Now compare that to the Chevy Bolt....which is an incredibly fun car to drive, despite being slower and having way less features. The thing is, a car enthusiast doesn't car about the tech or engineering details. Car enthusiasts just enjoy the process of driving. Sure, I might follow the tech to understand what I might like, but at the end of the day the Bolt is such a joy to drive. It's comfortable, puts you in touch with the road, inspires confidence, doesn't fight against you, etc.... and I've never worried about the braking system turning off on me. I have no idea if it could do a lap at VIR, but it certainly didn't complain when I drove the snot out of one just a few months ago. Trail braking in a Bolt? Heck ya. I wouldn't feel confident attempting that in a Model S. I know the pure car enthusiast is a minority, and Dave thinks they're all going away once AV's take over, but dang it I love driving. I just don't get pleasure from the Model S....and I went into it thinking it was one of the coolest things ever. I was even skeptical of Clarkson until driving one - and then it all made sense what he was saying. I'm surprised companies don't hire him to do consulting. Anyways, just one ignorant man's opinion....please don't be annoyed if you love the Model S. It's just not a sports or luxury car in my book. At that price point you could be in an Evora, or DB9, Porsche 911, or have three Bolts! Haha.

Tesla never had the tech advantage when it comes to AV.... Ford, GM, Volvo, Toyota, etc... have all been way ahead of the game. They just weren't announcing it because the technology wasn't ready yet. Heck, even Google (Waymo) is leap years ahead. This outta make Dave happy: https://waymo.com/apply/ I can tell you they're all way more advanced than Tesla's toys...oh, and they know what makes a good car too. The Model S is horrible from a car enthusiast perspective. I'd take the Chevy Bolt all day long over the Model S. I haven't driven a Model 3 yet though, but my expectations are low. As far as EV vehicles are concerned - keep an eye out for Chrysler. China is totally the world leader in terms of EVs right now, but once the battery industry hits a certain performance/price target, you're gonna see a crap ton of EV's pouring out of Chrysler. The engineering teams at the large automotive companies are totally aware of electric technology and are easily way ahead of the game. You just don't know it yet because batteries aren't ready to slam the industry yet. Many years ago I had predicted 2025 as the year that the battery market will hit those targets. Ironically, articles from several investment journals predicted the same year a few weeks after I shared my predictions with family and friends. They must have all attended the same conference and connected the same dots. At that point, I predict Tesla stops making cars - and they'll probably return to focusing on manufacturing batteries and capitalizing on power station infrastructure. It's possible they might stick around making cars if they actually learn how to make a good car, but I'm not holding my breath. It is interesting to me though that AV almost assumes EV in my head. If you can do AV, then it doesn't matter if its gas or electric, but it's a much more natural story to do AV with an EV. I think that's why the lines blur between the two. But ya, China is totally dominating the EV market right now - and for good reason because the air quality over there is horrendous. It'll be interesting to keep tabs on that too.

That's actually what prompted my study....the funny thing is I've concluded that we should embrace our audio biases. The thing about placebo effects is that the experience is entirely real for the end user. Shouldn't we be elated that they can get the same experience with a sugar pill and none of the other nasty side effects? The human experience is more than the mere physical realm, and we should embrace the biases that allow that to happen. Although we as engineers need to understand when that's happening - and really we should engineer both the physical reality and the biased perception at the same time.

Based on my current occupation, I think I might be fairly in the loop in regards to cutting edge electronics - especially in the computing space I would like to posit that focusing on operations per second is the wrong way to go about understanding computing performance - not that it's a totally useless metric, but it has little bearing on the actual final result. Just like putting a million horsepower in a car with Prius tires doesn't make any sense. It's the total solution that matters - not some arbitrary spec Most of the computing performance today gets wasted by sloppy programming. We did more with lessor processors in the past because we actually engineered the performance out of those chips. We're not touching the capability of the modern chipsets....we're just making it easier to write code. I wonder how much energy we waste every year on unnecessary computer cycles? Now that'd be a fun metric to calculate out.....I bet it's a huge number.

Moore's ceased to be true a while ago.

double post.

This has little to do with IQ - maybe more to do with cognitive bias? You should know better than to ascribe this personal experience to your understanding of the entire automotive industry. The failure rate of sensors is a measurable fact - you always tout being data driven. Why not here? On the subject of anecdotal experiences....I don't own a car with a backup camera, but I can easily cite dozens of experiences with others having a backup camera obstructed for some reason (usually environmental). It's not a big deal with a human driver because we still have mirrors and a human in control - every time I see something like that, I think about how an AV would try to cope with what I see on the screen. Would you be comfortable with a human driver with a similar amount of interference on their vision? Would you put your child in a car seat in that car knowing that's how the computer is seeing the world? I wouldn't. So ya - throw in the Lidar or whatever other fancy redundancy....they all have their blind spots, and it's more often than you might think. Since it came up, cognitive bias has been a study of mine for the last 2 years or so. I went through this Wikipedia list, one at a time: https://en.wikipedia.org/wiki/List_of_cognitive_biases It's fascinating to understand where our perspectives and emotional responses come from. I started off with the goal of freeing myself from bias, but that's simply impossible - nor ideal actually. It's best to understand when it happens, and then be open-minded in those situations.

I wouldn't bother with the KP-3002 for home use. I've had a pair in a pro-sound setting for over 21 years (wow, that makes me feel old). The used speakers in this category tend to have burned out resistors or coils in the xovers, which really makes them sound bad. It's not worth the hassle. If you go pro, get the KP-362.

Well crap, if we only needed motors and computers for an AV then we'd be all set! What about all the sensors?!? You do realize sensors are the most common repair to vehicles, right? You also realize that the main limitation to anything automated is heavily based on the sensory system? And we don't need to maintain those systems? Seriously? This isn't about holding onto the horse and buggy. It's about telling the emperor he has no clothes.

Right - and my point is that their success rate is attributed to the incredibly rigorous maintenance plans that have been put in place. Their methods and success rates are so good that it's been cause for all sorts of research into how those methods could be applied to other industries. Do you really think we're prepared for that level of maintenance across the entire automotive industry? The automotive mechanics I run into barely know ohms law, and complain about how complicated OBD-II can get...

Anyone here ever driven a modern Volvo or Land Rover for any length of time? They love having all sorts of features in their cars, and sensors to let you know when they're working....and they fail all the time. It's almost comical how bad it gets. There's a lot of debate about how good a perfectly working autonomous vehicle might be, but what happens after a few winters and stuff starts failing? What do you do about the camera that gets snow flung up on its lens, or the sensor that gets internal condensation causing it to slightly misread? Y'all proclaim the wonderful merits of cars working together in unison, with following distances much closer than humans could achieve safely. But even without that, it's not intrinsically safe for a car to just stop in the middle of the road - and how does it pull over to the shoulder when its sensors aren't functioning? Never mind the whole detection complexity.... these aren't things that you "just program". That's the myth of leaving it to software....this is a real hardware problem with no always works solution. The only way around that is what the airline industry does....which is massive amounts of maintenance overhead on every single component and sensor, and redundancy when possible. Your average car driver can't even change their own tires and brakes. Who here is going to be qualified to test all the sensors in their vehicle? I was just moving my stuff into the city yesterday...driving a 26ft box truck through tight narrow alleys. It was not possible to maneuver this vehicle and follow all the rules of the road. We had to stop and move items in the way, drive the wrong way down one-way streets, etc... We don't do it often (well most of us don't), but moving is a part of life and our existing infrastructure is not built to support automation of transportation. The reason the driver-less forklifts work is because the infrastructure is in place to control all the necessary variables. Could you imagine trying to move into a new home with an autonomous vehicle? Or use a vehicle to pull out a tree stump? We live in a real world, with real existing infrastructure. You don't change that in a few years. Totally anecdotal example, but it plays out in every facet of understanding our infrastructure. Btw, Travis....what do you consider truly autonomous? I think the definition of "driverless" is what most people understand to be autonomy....the car can perform all transportation functions without anyone in the car. I don't think Level 4 lets me put a pair of speakers in my car and have them delivered to my friend without me in the car....

Don't forget to multiply that by at least 4..... Marketing ploys to boost stock prices.

Keep an eye out for the dissipation factor (ESR) on the larger value caps. You can actually hit a point where the larger value capacitor is worse. To put it another way, if you're increasing the capacitance, then make sure the physical size is increasing too. These are horrible rules of thumb because this should be calculated, but that's beyond the scope of the forum. Most times it's probably better, but not always...

You guys are a bunch of nerds....I'm digging it. I intended the black color thing as a joke, but right on.....I learned something new about Pistol Shrimp! How long have you been doing the audio hobby? I can totally relate with your passion for learning everything under the sun. One of the reasons I love audio so much is that there is so much depth to the science, and the impact of that science engages our soul in the most artistic ways. Here are some cool websites I've come across over the years that have facilitated my learning outside the formal confines of college: https://www.prosoundweb.com/ http://quarter-wave.com/ https://www.klippel.de/know-how/literature/papers.html http://data-bass.com/home http://www.rane.com/library.html#gpm1_2 http://www.klipsch.com/dope-from-hope (super cool to see this on the klipsch website now) http://kolbrek.hoyttalerdesign.no/index.php/publications There have been all sorts of great articles published on the forum too - I just listed a few websites with a ton of articles for you to dive into. Happy reading!

One of the fun things about human perception is that if you think there's a problem, then you will experience a problem - regardless of what the physical world is doing (or not doing) around you. The mere fact that you're asking the question means you probably have this nagging thought in the back of your mind. If money isn't tight for you, then I'd recommend pulling a new wire so you don't have to doubt the influence of your interconnect. If money is tight, then rest assured that a good connection won't have any audible impact. We could get into a technical discussion about why it doesn't matter - or ways that it might matter, but that takes an electrical engineering degree and several years of experience dealing with circuits where the wire shape/size actually matters, or galvanic potentials, or oxidation layers, etc.....these are all very well understood fields with all sorts of maths that predict with incredible accuracy the kinds of impacts you might expect. At audio frequencies, you're going to see more influence from dust particles in the air interacting with the surface of your loudspeakers. Do you hear all the ticks and pops of those particles bouncing off the diaphragms? I hope that doesn't put another nagging thought in the back of your mind... Seriously, don't worry about it....and go back to tripping out over more exciting things, like the meaning of the color black and whether it's actually a color or not....can you ever truly experience the real color of black when it's the absence of color?

QSC HPR152 tweeter horn with BMS4550 driver, and I'm using an active xover (Crown XTi right now).

Saweet! You should let your parts team know that....otherwise I wouldn't have cut my Chorus II cabinets apart. Although I am enjoying my 2-way setup quite a bit. Unfortunately I didn't grab photos of the ports....just myself covered in the sawdust from all my free-hand routing, haha.

No - that doesn't work. The suspension of the passive radiator is much softer than the suspension of the active driver. This is how you tune the resonant frequency. The suspension of an active driver is way too stiff (and not hard to model actually). I would sooner use the KD-15 passive from the Forte III, but I think the risk is a design that is tuned too low and too narrow. Do you think you could get Klipsch to share the T/S parameters of the KD-15? Without that, we can't know how well it'd work in the Chorus II cabinet. If simply speakers has the correct recone kit, then you could use the recone kit with the existing driver frame and take off the magnet. That would probably be the second cheapest route. Btw, I checked my notes. The port holes were 3" in diameter and 0.75" deep (the thickness of the MDF). A passive radiator and normal port provide the same acoustic function. If you have the ability to cut circles, then this will by far be the easiest solution - and it's completely reversible should you decide to change your mind. Just use the same screws that were holding the passive radiator in place.

Let us know if you find a source for replacement passive radiators. Does Klipsch parts still have them? I ended up replacing my passive radiators with a standard port. Turns out you can cut a piece of wood to fit where the original speaker sat, and then cut a hole in it to achieve the same tuning. I wanna say (edit) 3" diameter with a 3/4" piece of MDF? I can measure for anyone wanting to do this themselves. Port velocity is a bit high, but I don't generally listen very loud. You could always go to a larger port if you really wanted to though. It was free for me to install the wooden plate. I think a pair of passive radiators would be about $150 if you could find a suitable replacement. I remember hearing at one point that Klipsch didn't have replacement parts, but maybe they do now. There are some other companies doing passive radiators that could probably drop-in.

Klipsch x7i (earbuds)

Sounds like they discovered a polarity problem in production, that they fixed at a later date....but he didn't want to come right out and say it

If the comb-filtering itself was the mechanism, then how is it that we can tell the difference between left and right? The resultant comb-filter would be the same.... Talking about time-arrival differences in the frequency domain is possible if you focus on the phase.....but it's not very helpful. Sure, you can point out the phase mechanism, but it's really simpler to just analyze the time-arrivals in the time-domain. This is because the mechanism on both ends is occurring in the time domain, so these things are more naturally described and understood that way. For example, you could create a matrix transfer function to force the world to be flat when visually represented, but it would just obfuscate the reality of the world actually being round. It just complicates the math unnecessarily. The fourier transform between the time and frequency domains would be a similar way of trying to over-complicate something that is otherwise quite straightforward and elegant. I personally prefer simple maths....I'm not smart enough to visualize crazy complicated calculus descriptions. The most advanced radar systems in the world are just now starting to mimic the incredibly elegant spectral smearing mechanism that our ears use for localization / spacialization. There is all sorts of great research on how our ears work and hear things. I was just at an AES meeting where they were talking about how this frequency dependent time smearing is the reason that frequency correction in hearing aids doesn't work for the "cocktail party setting". We need that localization function to focus our hearing to what we want to hear (like the person talking to us). The point is that comb-filtering is a horrible way to understand this - and you can't compare the comb-filtering of spacial reflections to the multi-dimensional localization mechanism of our ears. The processing on either end is different (1/4 wave reflection versus ear time-arrival) - even if you might see similarities in the frequency domain. Nowhere near as in depth, but here's an entertaining video highlighting how our pinnae are used for localization: (the part where he puts clay on his kid's ears)