The art of making good affordable loudspeakers

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Yes. A good article. I don't think anyone gave away any secrets though.

Dr. Jack Oclee-Brown said:
We always try and deliver both measured accuracy and musicality, but for an inexpensive or compact product it sometimes is not possible to do both. A classic example would be choosing between a flatter frequency response at crossover, or a higher crossover frequency that gives the tweeter an easier ride. We’d always aim to be able to do the former, but if in the listening this sounds strained or fatiguing we’d compromise the measured performance a little to give better musicality. Our best products are those where everything comes together nicely and there are fewer tough compromises in the listening room....

....Loudspeaker technology is very mature, and the fundamental behaviour has been understood for more than fifty years.

All is compromise.

Amusing comments section. A great deal of "Trump Derangement Syndrome" on display. You either know what that is, or you don't. :D
 
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FEA has been around and used in speaker design since the last century, its just you can run in on a laptop at home these days rather than an overnighter on a big hairy linux box. I have a lot of time for Andrew Jones, in other interviews he seems to really enjoy the cost constrained designs as it pushes him.


Now the thing they don't discuss is that, due to much higher volumes for lower cost units you can potentially make a better £150 speaker than a £500 one you have, say, 1e6 units to amortise tooling over so can do things you just can't with a more expensive but lower volume model. I think there is a cost:performance curve that is not really talked about in terms of where the sweet spot is above where you have to pay 10x or 100x more to get a real improvement rather than a bling paint job.
 
Jack O-B from KEF says
"We always try and deliver both measured accuracy and musicality, but for an inexpensive or compact product it sometimes is not possible to do both. A classic example would be choosing between a flatter frequency response at crossover, or a higher crossover frequency that gives the tweeter an easier ride. We’d always aim to be able to do the former, but if in the listening this sounds strained or fatiguing we’d compromise the measured performance a little to give better musicality. Our best products are those where everything comes together nicely and there are fewer tough compromises in the listening room."

I don't like the word musicality here at all, but I can understand this story. Modern diy design is perhaps too much going by good measurements. XO settings have many aspects and yes I can hear some changes there too and prefer to follow my ears!
 
Musicality is a thing I always seek. It is best understood by people who know what live music sounds like. I really couldn't give a monkeys about flat frequency response or dispersion. You get what you get. But it does no harm to get that right. All that stuff was understood 50 years ago as the KEF man said. It's why I love cone tweeters. So much nicer than domes.

Dean Hartley of Monitor Audio makes an interesting remark about designing for the low end:

Dean Hartley of Monitor Audio said:
...We also need to consider the typical quality of equipment being partnered with the speaker. An example would be with a two-way stand-mount speaker (like our entry-level Bronze 2), where the design must yield a more efficient output and easier load to get the best from an amplifier that may not have high current delivery...

That has gotta be right. Exotic amplification might deal with a wobbly impedance, mainly by wasting power as in Class A. For the low end, keep impedance as flat as you can. I say this as someone who has built and designed amplifiers. The problem is dealing with difficult loads. Because feedback designs just don't settle quickly with a high phase shift. Give a regular solid state Class B amp a capacitative load (where the impedance is on a steep downward slope) at low impedance, and it just doesn't know where to settle!

The budget end has driven us into certain styles. Reflex, because it's efficient for big bass in a small box. BBC style thin damped cabinets, because it's cheap and light. Low order crossovers, though I don't like them at all. Just a cheap solution, IMO. Maybe 5" bass because it's easy on time alignment and high crossover.

My current interest is very systems engineering oriented on crossovers. What does the amp see with the speaker load? What does the driver see of the amplifier control? I want them both in their comfort zone.

Jack Oclee Brown of KEF said:
Our best products are those where everything comes together nicely and there are fewer tough compromises in the listening room.

Quite. :cool:
 
I don't like the word musicality here at all, but I can understand this story. Modern diy design is perhaps too much going by good measurements. XO settings have many aspects and yes I can hear some changes there too and prefer to follow my ears!

There is certainly much more to crossover design than frequency response. With some low Fs 1" dome modern tweeters, by FR alone you might think you could cross it over at 800Hz! It's critical to do a distortion measurement on ALL drivers to see where in frequency and at what SPL level they start to "fall apart". That info is just as important as the frequency response (on and off axis) of the drivers in terms of choices made during the crossover design.

I would say a DIY designer who is paying attention should at least consider (1) on axis frequency response, (2) distortion vs frequency as a function of crossover frequency, and (3) off-axis response and beaming issues. After that would come (IMO) overall frequency extension and max SPL (again, this is distortion related), although these are probably more a function of the drivers and box than the crossover design, and so are constrained from the beginning.
 
A small deviation from the topic, but dsp and built-in amplifiers are getting more popular.
Now Dynaudio and Golden Air are on the scene too. They both have bass management with pre-set options. Looks like the implementation is different though.

Aussies have tested these , check on-line articles

Dynaudio Focus 60XD Speakers Review & Test | Hi-Fi | Review | AVHub
An externally hosted image should be here but it was not working when we last tested it.


GoldenEar Triton Two+ Plus Review & Test | Hi-Fi | Review | AVHub
An externally hosted image should be here but it was not working when we last tested it.
 
The trick is picking a set of drivers that can cover either others deficiencies. Building to a price and at volume throws a spanner in the works because the crossover can't be too complex and you have to account for manufacturing variability. Integrating a DSP into a product sure solves a lot of those concerns.

One of the problems with modern speakers is that they must be able to handle artificially bass-heavy music [or computer generated noise] without failing within the warranty period.
Indeed that has become the first priority rather than sound quality.
Some of the solutions to this are quite clever, such as digitally synthesizing bass harmonics and removing the fundamental so that smaller speakers can produce strong bass without needing much excursion capability.
 
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