Here is a link to last year's event.
Note, Iowa is put on by the Midwest Audio Club which also hosts the MAC forum (linked).
2025 dates are not set but it is almost always in October.
https://diy.midwestaudio.club/discussion/2693/iowa-diy-2024-10-18-10-19/p1
Bashing DSP makes no sense, even if all active DSP loudspeakers at AXPONA 2025 were bad sounding. Maybe those loudspeaker were bad not because of DSP, but because of something else? That will make DSP to be a collateral damage - not the cause of bad sound at all.
I found this comment particularly good:
I should throw my own 2 cents in on the whole DSP, active vs. passive thing here. I have a HT setup with larger bookshelf monitors doing L and R and an active center using Hypex plate amps and DSP. They mesh perfectly. I simply cannot in my home tell that the center is relying on DSP while the L and R are relying on passive crossovers. In fact my HT processor has a bug that sometimes it uses the center channel and sometimes it does not when it should. If I"m sitting in the center I 100% cannot tell if the center is on or not without examining the display screen and knowing the source.
So maybe there are those here who 100% can hear DSP based crossovers and EQ, but I am personally kind of grateful I cannot.
In terms of EQ curve, I do deliberately match the center channel to the L and R, which does not really take a lot. Little help here and there, definitely no attempt to correct every nook and cranny of the tweeter response. Harsh? Grainy? Definitely not for me. Maybe I should attempt Dirac Live or something like that and see if I can make them sound bad. 😉
So maybe there are those here who 100% can hear DSP based crossovers and EQ, but I am personally kind of grateful I cannot.
In terms of EQ curve, I do deliberately match the center channel to the L and R, which does not really take a lot. Little help here and there, definitely no attempt to correct every nook and cranny of the tweeter response. Harsh? Grainy? Definitely not for me. Maybe I should attempt Dirac Live or something like that and see if I can make them sound bad. 😉
It's a close parallel to those car guys who still say that carburetors are better than fuel injection and that they can tune their carbureted 350 chevy to run better than any modern fuel injected v8.
Having worked on and driven a plethora of vehicles over my life, there is still something to be said for carburetors. When I drive a vehicle with a carburetor, I don't have an algorithm looking at engine coolant temp, vehicle speed, throttle angle and gear position to 'intervene' in power delivery if it thinks I might be half @$$ed abusive towards the driveline or engine. If the stars aren't aligned, and it decides to cut ignition advance by 30 degrees because 'it' feels like it when you open the throttle, makes it a dog to drive.
At least with aftermarket tuning or aftermarket ECU's you can minimize the nanny features built into the OE ECU's. Modern GDI engines tendency to carbon up the intake valves is problematic, something that didn't happen with carburetors or even port injection.
Now let's compare the power, towing, fuel mileage, longevity, and weather/altitude adaptability of a 2025 Silverado with its EFI to a 1985 C10 with its 150hp carbureted 350.. see if that new Silverado gets vapor lock on those hot summer days.. that's the point. 😉
I just did at an industry convention, the CCL compact arrays, not the GSL though. Low / mid reduction at the rear of the array was noted. It was the female companion that piped up they just didn't sound clean, more like a big bluetooth speaker. Fuzzy.
I was not impressed with the listening portion of the presentation, at all.
Product use / placement / acceptance doesn't mean the product is good.
Gee, if we took that LT engine and put a carburetor on it, and tuned it with the aid of a 5 gas analyzer, it would make within a few percent of the power that the GDI engine would. You are comparing apples to grape fruit.
Decades of improvements such as roller lifters, roller rocker arms, low tension piston rings, friction reduction coatings on the pistons, computer optimization of piston crown shape and combustion chamber result in much more efficient powerful engines. In 1985, none of these technologies made it into the half tons.
It's possible that a mostly original 1985 C10 will still be driving today, 40 years after rolling off the assembly line. I don't see a 2025 making 40 years. When the ginormous screen breaks in it, likely irreparible. Will the power multi-way tailgate function after 40 years?
As the owner of a ~550hp reliable 2.0L turbo hatchback, and the previous owner of a ~300hp 5.8L carburettored 1960s sedan - I think DSP is great
Either he misspoke when you were there or you mis-heard. When I was in the room he said 30 or 40 degree (don't remember) window - gesturing to the whole seating area - they sound the same.
At any rate, the larger model's performance is known. Erin characterized it here: https://www.erinsaudiocorner.com/loudspeakers/kii_three/
Note that the vertical dispersion is also much wider than any wiggly strip of Reynold's Wrap can offer.
Calling BS on that one... this kind of noxious misinformation really has no place among people who can hear.
If you put the carburetor on the LT, you would still have to re-jet it at different altitudes and it would still have terrible cold starts. EFI will start and run perfectly without hesitation in -10 degree or 110 degree weather, at sea level or on Pike's Peak, without adjusting a thing. A Holley 4150 will not.
You're missing the forest for the trees with the carb vs. EFI comparison. This discussion here pretty much illustrates my point.
I love driving my '85 C10 with its quadrajet, but I'm not going to pretend like it has any drivability advantage over my other driver, a 2005 tahoe with its EFI and almost 300k miles. The C10 is getting a LS swap this summer so that I can drive it in the winter without worrying about flooding out on those cold starts. 😉
no BS involved, if you want to maximize the RAAL 140 or 70 ribbons to there full potential you need a very nice network and amplifier to do so, that's fact. we have tested them thoroughly with many network parts and they require the best IMO to get the resolution etc they are capable of, will they work with low end networks and a Yamaha receiver to power, sure, but you will lose alot. also tried these in a 2 way monitor design using nice hypex amps and there dsp, not my cup of tea or the RAALS either
Sounds like it was not tuned correctly out front. I've heard a lot of D&B rigs and they are not fuzzy and they definitely don't sound like a bluetooth.
Then what does it mean when the top live artists and engineers choose that product over every other product available?
That is a possibility, one of many possibilities.
Another company had a Tri-axial point source box displayed that sounded like someone duct taped a pillow over the front of it. 🤣
Certainly no where near as good as the RCF and Meyer demos that I attended.
In 1990 I picked up my first bona fide speaker installation client. His desires were pretty ambitious, so I put together an active crossover to drive the subwoofer. I ordered a 2-way active crossover board from a reputable supplier and hooked it up.
I was dismayed at the amount of degradation the active crossover stage introduced to the signal. For the satellites, the crossover added noise and a layer of film typical of many active amplification stages. We've all heard the same problems from receivers, preamps, amps, mixing boards, and buffers, because any active amplification device adds its own signal degradation that passive devices do not have.
The active crossover board was an unacceptable solution.
So I opted for something completely different, which I have rarely seen anybody do. I implemented a 2nd order passive line level crossover using inductors, capacitors, and resistors.
When you do that, you find that the inductance values go up by a factor of a thousand, and instead of having 5 MilliHenry inductors, it had 5 HENRY inductors, which I had to custom order from Hammond transformer company. (Yes, 5H inductors do exist.)
I designed the circuit so that his preamp saw a 600 ohm load when it drove the crossover, and we used switches to add extra capacitors and toggle the crossover frequency between 50 Hertz and 80 Hertz. I used potentiometers to vary the resistance seen by the LC circuit so that I could also vary the Q at the knee of the crossover.
It worked exactly the way that I wanted it to. His preamp didn't have difficulty driving the circuit, and it completely bypassed all of the weaknesses of active amplification circuits and all of their associated noise. It was a great solution.
The circuit was susceptible to hum, so you had to physically place it so as to not exacerbate that issue.
The lesson was that the ills of passive components like capacitors and inductors are far less onerous than the evils of complex active circuits. Anytime you can solve a problem using a "bow and arrow" instead of "nuclear weapons", you should.
One theme in audiophile experience that many if not most can agree upon is that many times when you opt for nuclear weapons instead of bow and arrow, you can hear the extra complexity as an artifact.
The degree to which people find this objectionable varies from person to person. Some people are more sensitive to the problems that DSP can easily fix… and less sensitive to the complexity artifacts.
Others are extremely sensitive to complexity artifacts and much more tolerant of the problems simple systems tend to have (like problems in frequency response). This is why some greatly prefer full-range speakers and single-ended tube amps.
This speaks to a general truth of problem solving: that if you want to solve a complex problem using a bow and arrow, it takes a great deal of ingenuity, and that throwing complex technology at a problem often fails to solve it.
From my own personal POV, good quality DSP units successfully bypass the problem I had in the 80s, which was that an active crossover added an entire stage of analog active stage distortion. With DSP, the signal is digital from source to crossover all the way to the D to A converters which feed straight into the amp.
So as far as I’m concerned, I get the best of both worlds. So I’m a fan of DSP speakers.
But it does come with a few caveats. First of all, the system is only as good as the D to A converters in your digital crossover. So if a MiniDSP Flex Eight does not have as good DA converters as your preferred audiophile music streamer, you have a problem.
Tom Perazella uses a Danville Signal $4000 unit which according to Danville uses the best D to As in the business, and the Danville Signal guys say not all mathematical implementations of an IIR filter are equal. There are many standard off-the-shelf IIR algorithms that introduce subtle problems, and there are other algorithms that are much less commonly used that have fewer artifacts. I’m not a Danville owner so not in a position to verify this. Y’all can research that detail to your heart’s content.
In any case, solutions that look fabulous on paper don’t always sound as good as they’re “supposed to” and hi tech solutions sometimes take shortcuts that would never be apparent on a spec sheet. I don’t find it difficult to believe that a $1000 DSP unit adds distortions that good old fashioned inductors and capacitors avoid. But an old fashioned system is likewise only as good as its upstream D to A converters.
I was dismayed at the amount of degradation the active crossover stage introduced to the signal. For the satellites, the crossover added noise and a layer of film typical of many active amplification stages. We've all heard the same problems from receivers, preamps, amps, mixing boards, and buffers, because any active amplification device adds its own signal degradation that passive devices do not have.
The active crossover board was an unacceptable solution.
So I opted for something completely different, which I have rarely seen anybody do. I implemented a 2nd order passive line level crossover using inductors, capacitors, and resistors.
When you do that, you find that the inductance values go up by a factor of a thousand, and instead of having 5 MilliHenry inductors, it had 5 HENRY inductors, which I had to custom order from Hammond transformer company. (Yes, 5H inductors do exist.)
I designed the circuit so that his preamp saw a 600 ohm load when it drove the crossover, and we used switches to add extra capacitors and toggle the crossover frequency between 50 Hertz and 80 Hertz. I used potentiometers to vary the resistance seen by the LC circuit so that I could also vary the Q at the knee of the crossover.
It worked exactly the way that I wanted it to. His preamp didn't have difficulty driving the circuit, and it completely bypassed all of the weaknesses of active amplification circuits and all of their associated noise. It was a great solution.
The circuit was susceptible to hum, so you had to physically place it so as to not exacerbate that issue.
The lesson was that the ills of passive components like capacitors and inductors are far less onerous than the evils of complex active circuits. Anytime you can solve a problem using a "bow and arrow" instead of "nuclear weapons", you should.
One theme in audiophile experience that many if not most can agree upon is that many times when you opt for nuclear weapons instead of bow and arrow, you can hear the extra complexity as an artifact.
The degree to which people find this objectionable varies from person to person. Some people are more sensitive to the problems that DSP can easily fix… and less sensitive to the complexity artifacts.
Others are extremely sensitive to complexity artifacts and much more tolerant of the problems simple systems tend to have (like problems in frequency response). This is why some greatly prefer full-range speakers and single-ended tube amps.
This speaks to a general truth of problem solving: that if you want to solve a complex problem using a bow and arrow, it takes a great deal of ingenuity, and that throwing complex technology at a problem often fails to solve it.
From my own personal POV, good quality DSP units successfully bypass the problem I had in the 80s, which was that an active crossover added an entire stage of analog active stage distortion. With DSP, the signal is digital from source to crossover all the way to the D to A converters which feed straight into the amp.
So as far as I’m concerned, I get the best of both worlds. So I’m a fan of DSP speakers.
But it does come with a few caveats. First of all, the system is only as good as the D to A converters in your digital crossover. So if a MiniDSP Flex Eight does not have as good DA converters as your preferred audiophile music streamer, you have a problem.
Tom Perazella uses a Danville Signal $4000 unit which according to Danville uses the best D to As in the business, and the Danville Signal guys say not all mathematical implementations of an IIR filter are equal. There are many standard off-the-shelf IIR algorithms that introduce subtle problems, and there are other algorithms that are much less commonly used that have fewer artifacts. I’m not a Danville owner so not in a position to verify this. Y’all can research that detail to your heart’s content.
In any case, solutions that look fabulous on paper don’t always sound as good as they’re “supposed to” and hi tech solutions sometimes take shortcuts that would never be apparent on a spec sheet. I don’t find it difficult to believe that a $1000 DSP unit adds distortions that good old fashioned inductors and capacitors avoid. But an old fashioned system is likewise only as good as its upstream D to A converters.
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Once I ran across an article in a train magazine from the 1970s. At that time there was only one steam locomotive still operating in the world, I think it was in Siberia. It was soon to be replaced with diesel. The steam engine aficionados were lamenting the sunset of a technology they were fond of.
The article explained (to my surprise) that steam engines have a number of significant technical advantages as compared to diesel engines, in particular situations.
If you want to go down that rabbit hole you can here: https://www.perplexity.ai/search/i-understand-that-back-in-the-hbT9uMRYRWOh95eEaH_fBA
The point being that even very old "antiquated" technologies have their charms and yes at times do have advantages over the new. There are sometimes strong reasons to hang on to the old.
Oh no, in the seventies there were still hundreds of steam locos active on a daily basis. The largest numbers in Poland, but also in other East Bloc countries.
Even in the West, West Germany operated steam loco's until mid 1976. South America also had active steam in the seventies.