Vandersteen VLR Speaker Review

[Ron Texas]

I love bad reviews of gear from famous designers. Thank you @amirm

 

[fpitas]

The first clue is the required 50-hour break in period. It just gets fishier from there.

 

[CHenry]

The first clue is the required 50-hour break in period. It just gets fishier from there.

There seem to be plenty of manufacturers that place similar recommendations on their products. It's hard to make much of it except that some users of some products appear to validate the need for a period of use of a speaker for it to achieve its full voice, its expected performance. Makers of truly custom reproduction horns make similar claims and appear to run their units for a fixed period of time before delivering to the buyer. You can dispute the importance, but if the manufacturer says that a "burn-in" period is necessary, that probably has some significance. It might be interesting to see objective testing pre and post burn-in to tell if it is quantifiable.

 

[fpitas]

if the manufacturer says that a "burn-in" period is necessary, that probably has some significance

Yeah? Permit me to doubt that very much. Amir quantified burn-in, finding nothing. I've seen plenty of analyses during the design stage showing the driver parameter changes tend to cancel.

 

[Everett T]

There seem to be plenty of manufacturers that place similar recommendations on their products. It's hard to make much of it except that some users of some products appear to validate the need for a period of use of a speaker for it to achieve its full voice, its expected performance. Makers of truly custom reproduction horns make similar claims and appear to run their units for a fixed period of time before delivering to the buyer. You can dispute the importance, but if the manufacturer says that a "burn-in" period is necessary, that probably has some significance. It might be interesting to see objective testing pre and post burn-in to tell if it is quantifiable.

Imagine if the parameters change enough to change the sound, now imagine trying to design a speaker with that in mind. Then only break in period for a speaker is once the VC gets warm. There have been some tests done over the years and the difference produced with T/S parameters has been extremely small and not near great enough to be audible.

 

[fpitas]

What burn-in certainly is, is audio woo-woo that sells to a certain crowd. They seem to want to believe in it.

 

[Orion76]

Headphones only, but rtings did a nice break-in test-

Is Headphones Break-in Real? 120-hour Burn-in Test

Headphones break-in, or burn-in, refers to the idea that the sound of headphones tend to change over time and certain headphones need to be used for a while before they settle into a more optimum sound. We put this idea to the test.

www.rtings.com

 

[Patrick Bateman]

I have a subwoofer in my attic made by Final Sound in the Netherlands that hisses quite loudly. It isn't a high frequency hiss, but it makes it fairly far into the midrange (like a shell held up to your ear) so it is audible noise that you can hear when music isn't playing (basically the amp has too much gain). Fortunately the amp blew up and it got retired.

I do suspect, however, that the Vandersteen sub has less issue because the increase in gain is over a narrow bandwidth, meaning the gain never has to get too high.

Ground loop. You have a ground loop.

It hisses in the attic because you created a ground loop.

I had the *exact* same problem for years, until I learned a little bit about grounding. It's unreal how much a good ground can improve the sound of your active speakers.

If you want to run down a rabbit hole, you should see the nightmare stories from the car audio folks, with their piles of amplifiers and DSPs and a hundred feet of interconnect and wiring.

 

[Patrick Bateman]

I keep thinking I want to do a 4th order bandpass and put it in the attic, or under the floor, and bring it into the room via an aero port.
But I keep thinking that the transient response is probably not ideal.
It could be an easy way to at least get the bass into a mixed use room without getting WAF bent.

So it would be “in the attic”, but… “Not in the sense that you mean.”

I'm hardly an expert on transient response, but as I understand it, transient response is largely dependent on frequency response, the rolloff in particular.

In other words, the negative opinion of bandpass subs isn't because you have a sub that's radiating it's output through a port, the negative opinion of bandpass subs is because you have a sub that radiating it's output through a port and that port acts as a filter.

With that idea in mind, you can make a bandpass sub behave quite nicely if you're careful with the response shape of the highpass and low pass filters and the crossover to the mains. In particular, since there's already an acoustic filter in place (the port) you can use low pass filters on the sub that are quite a bit shallower than you normally would.

Earlier this year I'd been messing around with dipole subs, and realized I can make other subs sound quite similar to dipole subs with careful manipulation of equalization and the xover between mains and subs.

I think what a lot of people do is that they just reflexively (no pun intended) use steep high pass and low pass filters when they cross their subs to their mains. And that's rarely ideal, because... it screws up your transient response.

If you really want to get into the weeds with this stuff, you can start adding delays to the mains to line up the arrival times of the sub and the mains. This will do even more to improve the transition. There are entire books written on this, it's complex.

 

[norman bates]

From Elliot sound productions.

Phase, Time and Distortion in Loudspeakers

sound-au.com

Eventhen, wall reflections smear it.
I was a 6db time/phase flag carrier until I listened to this on headphones.
Granted, the Mic is very near field, not 10' away where the 5" would have not much below 200hz.

It is easy to hear it as different, not necessarily better.
Dispersion, resonances, distortion, waterfall, and freq response often swamp a perfect transient response to me.

I think one could make an active 2 way then dsp flat.....
And flip between 6db crossover and then another slope (changing polarities).....

I think we would perceive it as different, necessarily better or worse.

I read on DIY that lining up the centers was easier to perceive outdoors without all the room reflections.

 

[raindance]

Ground loop. You have a ground loop.

It hisses in the attic because you created a ground loop.

I had the *exact* same problem for years, until I learned a little bit about grounding. It's unreal how much a good ground can improve the sound of your active speakers.

If you want to run down a rabbit hole, you should see the nightmare stories from the car audio folks, with their piles of amplifiers and DSPs and a hundred feet of interconnect and wiring.

No. It's a crappy amplifier.

 

[CHenry]

I love bad reviews of gear from famous designers. Thank you @amirm

Your choice. I don't mind bad reviews if they are honestly founded and reviews of products good or bad have value only when they test the products as they are designed to be used, and not just any way the reviewer chooses to test them.

 

[MattHooper]

From Elliot sound productions.

Phase, Time and Distortion in Loudspeakers

sound-au.com

Eventhen, wall reflections smear it.
I was a 6db time/phase flag carrier until I listened to this on headphones.
Granted, the Mic is very near field, not 10' away where the 5" would have not much below 200hz.

It is easy to hear it as different, not necessarily better.
Dispersion, resonances, distortion, waterfall, and freq response often swamp a perfect transient response to me.

I think one could make an active 2 way then dsp flat.....
And flip between 6db crossover and then another slope (changing polarities).....

I think we would perceive it as different, necessarily better or worse.

I read on DIY that lining up the centers was easier to perceive outdoors without all the room reflections.

I don't even know what was being tested exactly there, but I closed my eyes and listened and the sound kept going from sounding small and "congested" to more open, enveloping and rich. Watching the video it was the small speakers that were producing that congested sound. I don't know of course how everything actually sounded in the room.

 

[Holmz]

I am usually surprised at how we, as a group, look at frequency domain plug with total confidence.
But an impulse response garners a, “Huh what dat?”response… or that ears do not do impulse and time domain.

 

[IPunchCholla]

I am usually surprised at how we, as a group, look at frequency domain plug with total confidence.
But an impulse response garners a, “Huh what dat?”response… or that ears do not do impulse and time domain.

For me, that's because the impulse response is a bit harder to conceptualize, even though it can be generated from the frequency response (and vice versa). I mean, I pretty much understand what being 5dB down at 1k will sound like, but have a much harder time gathering that same information from impulse response. Likely some of it is familiarity, but some is how the information is presented.

 

[Holmz]

For me, that's because the impulse response is a bit harder to conceptualize, even though it can be generated from the frequency response (and vice versa). I mean, I pretty much understand what being 5dB down at 1k will sound like, but have a much harder time gathering that same information from impulse response. Likely some of it is familiarity, but some is how the information is presented.

I think one can have two systems with identical frequency response, but different time domain response??
Much in the same way that one can have a picture with a histogram distribution of grey-scale, that same as another picture… but the pictures are vastly different scenes..

 

[Endibol]

I think one can have two systems with identical frequency response, but different time domain response??
Much in the same way that one can have a picture with a histogram distribution of grey-scale, that same as another picture… but the pictures are vastly different scenes..

You are right: think of two frequency spectra of a song played normally and the same song played backwards; they are exactly the same.

 

[Holmz]

You are right: think of two frequency spectra of a song played normally and the same song played backwards; they are exactly the same.

And that is where the expression, “The Devil is in the details” comes from.

 

[IPunchCholla]

I think one can have two systems with identical frequency response, but different time domain response??
Much in the same way that one can have a picture with a histogram distribution of grey-scale, that same as another picture… but the pictures are vastly different scenes..

Maybe I confused, actually probably I am confused, but REW says this:

Before we can get very far in interpreting an impulse response we need to understand what an impulse response is. The impulse response is in essence a recording of what it would sound like in the room if you played an extremely loud, extremely short click - something like the crack of a pistol shot. The reason for measuring the impulse response (by more subtle means than firing a gun in the room) is that it completely characterises the behaviour of the system consisting of the speaker(s) that were measured and the room they are in, at the point where the measurement microphone is placed. An important property of an impulse, not intuitively obvious, is that it if you break it up into individual sine waves you find that it contains all frequencies at the same amplitude. Strange but true. This means that you can work out a system's frequency response by determining the frequency components that make up its impulse response. REW does this by Fourier Transforming the impulse response, which in essence breaks it up into its individual frequency components. The plot of the magnitude of each of those frequency components is the system's frequency response.

So my understanding is they are two different representations of the same thing and can be transformed back and forth. Why impulse response is important is:

When an impulse response is measured by means of a logarithmically swept sine wave, the room's linear response is conveniently separated from its non-linear response. The portion of the response before the initial peak at time=0 is actually due to the system's distortion - looking closely, there are scaled down, horizontally compressed copies of the main impulse response there - each of those copies is due to a distortion harmonic, first the 2nd harmonic, then the third, then the fourth etc. as time gets more negative. The initial peak and its subsequent decay after time=0 is the system's response without the distortion.

 

[MarkS]

"An important property of an impulse, not intuitively obvious, is that it if you break it up into individual sine waves you find that it contains all frequencies at the same amplitude. Strange but true."

"So my understanding is they are two different representations of the same thing and can be transformed back and forth."

Not quite. You can get the frequency response from the impulse response, but not the other way around. This is because the equal-amplitude sine waves in the (perfect) impulse have another property: they all have a maximum at time zero (the time of the impulse). But a flawed speaker (and they're all flawed) will not put all the peaks at time zero, but have the peaks at slightly different times. This is called "phase response". If you know both the "frequency respsone" (the amplitude of each sine wave) and the "phase response" (the offset of each sine-wave maximum from time zero), then you have enough info to reconstruct the impulse ressponse (what the speaker produces given a perfect input impulse).

Incidentally, a perfect impulse is mathematically a "Dirac delta function", invented by physicist Paul Dirac: https://en.wikipedia.org/wiki/Dirac_delta_function. I'm pretty sure this is why the Dirac room correction system was given that name.