Meyer Sound: studio reference monitor

[617]

Thanks for the link--to tell you the truth it paints far too rosy a picture with the simulations; the on axis msmt in particular is fantasy. Olson's paper from way back in the 50's say so, and if you have ever used either Tolven's or Bagby's simulators, its ugly and counterintuitive. I guess what I found was questionable was the implication that anything without a wave guide should automatically be relegated to second class status. There are a great many exceptionally fine loudspeakers that don't benefit from wave guides. I suppose as a hobbyist who build loudspeakers I took exception, because it seems to suggest why bother? It's only going to be second rate. But it's not the case. I know there are many theoretical reasons for believing the pathway to greater fidelity involves using as such, but in practice, things are squishier. If you look at the link below your original comment, the msmts and review of this speaker turn out very well indeed. So I guess just as are apt to dismiss miniscule differences in sould quality from different DAC's, lets try to avoid overstating differences in potential outcome based on a set of assumptions that don't always reflect the real world behavior of audio devices. I use brick wall filters (a no-no in controlled directivity land) and I have cut corners and failed to round or chamfer edges, or use 6.5" woofers to 3k (eek, you're blinding me with that laser beam)--and had superb results. Not sure if they could have been made better--at some point it is sufficiently good it doesn't matter.

Dogma can be a terrible thing in all its guises.

Oh and if one wants to play with diffraction--this is quick and dirty and doesn't require EXCEL: http://www.tolvan.com/index.php?page=/edge/edge.php

Flat baffle speakers have waveguides. They have 180 degree waveguides with haphazardly designed terminations. Literally the only reason not to address treble dispersion is because it's difficult.

It doesn't mean diy isn't feasible, a 3 way can offer pretty smooth DI, but a slightly shaped tweeter faceplate at least is almost always a good thing. In a two way? Mandatory. Fortunately for us diy people there are some good options for waveguides, including some new high end offerings from SB.

More tongue point of the thread, the old Meyer sound monitors are ancient and should be judged as such. Interesting technology for the time. The new ones? Pricey but you're paying for a relatively sophisticated interface and bass management features so it is decidedly a pro product. However, the measurements do look good. I suspect they represent poor value for a typical enthusiast, especially compared to the JBL 708 and so on.

 

[Dennis Murphy]

. In a two way? Man

If you really know what you're doing, a wave guide can confer some distinct advantages in a 2-way design. More often than not, wave guides just introduce colorations and limit dispersion. If you're ever in the Washington D.C. area, feel free to drop in and listen to a $900 2-way Revel wave guide speaker and compare it with a $300 conventional 2-way. Blinded, of course.

datory.

 

[thewas]

I brought it up in the R200 thread as a point of comparison, but here I'm just pointing out that waveguides aren't always perfect solutions.

Of course not, but if done well usually a quite superior solution to a 8" 2-way without any and it seems the also Meyer that later agreed so and now offers monitors with it, like the

The Amie at least seem to measure very well.

Anyway, I just don't think it's enough data to make a meaningful assessment.

I agree, but its pure physics that a 8"/1" without waveguide cannot have really smootj directivity, which will show in even higher angles more.
Also about for the 1030A, here are more radiation measurements of its later cheap clone, the Behringer 2031:

 

[thewas]

Thanks for the link--to tell you the truth it paints far too rosy a picture with the simulations; the on axis msmt in particular is fantasy.

The on-axis is normalised to linear response to be able to show better the directivity behaviour and its not difficult nowadays in times of active or even more DSP crossovers to EQ it to flat which is also done in reality in many loudspeakers.

I guess what I found was questionable was the implication that anything without a wave guide should automatically be relegated to second class status. There are a great many exceptionally fine loudspeakers that don't benefit from wave guides. I suppose as a hobbyist who build loudspeakers I took exception, because it seems to suggest why bother? It's only going to be second rate. But it's not the case. I know there are many theoretical reasons for believing the pathway to greater fidelity involves using as such, but in practice, things are squishier.

We are here in ASR, where we comment the objective side, that is measurement side, of audio devices. You will always find people who love any kind of weird FR and distortion, discussing about taste doesn't of course make sense. But here the plurality agrees that smooth on and off-axis measurements are a prerequisite for neutral sound reproduction. As a hobbyist myself I am also building loudspeakers without waveguides because I cannot do better and some of them don't sound too bad, but on the other hand I am fully aware of their limitations and problems and can actually also measure and hear them at my listening position.

If you look at the link below your original comment, the msmts and review of this speaker turn out very well indeed.

As said the measurements are only limited to small angles and as you surely know you will find positive subjective reviews about any audio device.

 

[thewas]

If you really know what you're doing, a wave guide can confer some distinct advantages in a 2-way design. More often than not, wave guides just introduce colorations and limit dispersion. If you're ever in the Washington D.C. area, feel free to drop in and listen to a $900 2-way Revel wave guide speaker and compare it with a $300 conventional 2-way. Blinded, of course.

In my lively room non its the opposite, I can hear and measure at my listening position the problems of non smooth directivity and sound power of all the 2-way loudspeakers without waveguides of my collection compared to ones with well engineered waveguides.

 

[ctrl]

The HD-1 monitors have come up as a topic several times now.

Now I am so curious that I have set up a BEM simulation of the speaker - will still calculate a few hours.
After that, we will at least be able to make reasonably accurate statements about the directivity of the speaker.

Have taken the dimensions of the drivers from photos as best as I can - the simulation is certainly not exact, but certainly accurate enough that no surprises are to be expected compared to real measurements (apart from resonances).

Does anyone know anything about the crossover frequency and filter slope of the HD-1 monitors?
With this information, we can then create a complete simulation of the vertical and horizontal frequency responses.

 

[JRS]

Flat baffle speakers have waveguides. They have 180 degree waveguides with haphazardly designed terminations. Literally the only reason not to address treble dispersion is because it's difficult.

It doesn't mean diy isn't feasible, a 3 way can offer pretty smooth DI, but a slightly shaped tweeter faceplate at least is almost always a good thing. In a two way? Mandatory. Fortunately for us diy people there are some good options for waveguides, including some new high end offerings from SB....

Fair points. But I still maintain that damn good speakers can be designed without multifaceted baffles (arguably the best solution sans waveguide) to which I assume you are referring by "haphazardly designed terminations." More often than not the tweeters are placed symmetrically which flies in the face of the need for variable path lengths, and instead are simply beveled. Mind you I am not advocating eschewing WG's when available, just that this limits ones choices considerably, and perhaps unnecessarily.

 

[ctrl]

So, my PC has finished calculating the simulation.

The VCAD project directory is attached, so everyone can create a crossover and see what happens to the sound power, DI and the off-axis FR when the axis frequency response is tuned to +-1dB as specified in the manual.

Simulation Meyer-Sound HD-1
The simulation is valid only in the frequency range 200-13kHz, the BR port was not simulated. Simulated distance is 2m. The simulations can, of course, only be an approximation of the real behavior.

Sketch:


With simple LR4 crossover @2kHz:

With simple LR2 crossover @1.7kHz. This could possibly be realized, depends on the 8'' woofer break-up:

Depending on the selected and feasible crossover, the directivity of the HD-1 is not extremely bad, but no longer competitive in the price range.


The directivity using the first crossover (LR4@2kHz) example, then looks like this - normalized sonogram, -6dB limit is black line:

Very wide dispersion in the high frequency range, with severe narrowing around 1kHz due to woofer beaming.

Update: In the VCAD project, make sure that 200-13000Hz is set as the frequency range in the options and that CTA-2034-A is activated.

 

[Dennis Murphy]

In my lively room non its the opposite, I can hear and measure at my listening position the problems of non smooth directivity and sound power of all the 2-way loudspeakers without waveguides of my collection compared to ones with well engineered waveguides.

My invitation stands.

 

[617]

My invitation stands.

Dennis I appreciate your generosity. I'm speaking in generalizations and in the context of the Meyer hd1.

In my experience, if your woofer is kept smaller than 150mm, you can get smooth DI with a normal dome tweeter like or Morel or Rs28f or something. Maybe even a 25mm or smaller tweeter.

However if I was trying to do a 180mm woofer I think you'd want to be looking at a SS d2905 (9900) and even then your directivity will start to be a bit irregular.

For a professional speaker which has to just work in a variety of environments, you'd want a waveguide for an 8 inch woofer. Nowadays we have better woofers, so maybe we can get the same output from a 180mm woofer.

Have you ever made a good sounding 8 inch two way?

 

[Dennis Murphy]

Dennis I appreciate your generosity. I'm speaking in generalizations and in the context of the Meyer hd1.

In my experience, if your woofer is kept smaller than 150mm, you can get smooth DI with a normal dome tweeter like or Morel or Rs28f or something. Maybe even a 25mm or smaller tweeter.

However if I was trying to do a 180mm woofer I think you'd want to be looking at a SS d2905 (9900) and even then your directivity will start to be a bit irregular.

For a professional speaker which has to just work in a variety of environments, you'd want a waveguide for an 8 inch woofer. Nowadays we have better woofers, so maybe we can get the same output from a 180mm woofer.

Have you ever made a good sounding 8 inch two way?

This is a complicated subject, and generalizations are dangerous. The cosmic issue is whether very well controlled directivity at wide angles is as important as often maintained. Even Floyd Toole says it's the "icing on the cake," and that early arrivals are what really establish the tonality and quality of a speaker. That has certainly been my experience. I would rather listen to a 6.5" speaker with an off-axis dip in the crossover region but wide dispersion in the highs, than a speaker with a smooth but monotonically declining response. The Harman group offers the best engineered wave guides, and I don't doubt that the higher end models avoid the problems I'm hearing in less expensive 2-ways. (That may be because they're mostly 3-ways that don't run the tweeter as low as in a 2-way.) But even the Revel I have here suffers from the tell-tale cupped coloration I'm hearing in all of the less expensive 2-way wave guide brands, although to a much lesser degree. The speaker I would offer for comparison has a $17 6.5" woofer and a $15 dome, both Parts Express Dayton models, crossed at 1900 Hz. The tweeter flange is flat with no horn loading and has wider dispersion than other models with contoured flanges. I prefer it--you might or might not--but I don't think there's a scientific bass for dismissing a 6.5" speaker out of hand because it doesn't use a wave guide. Things get dicier with an 8" driver. I've designed a couple that sounded pleasing on their own, but did suffer in comparison to a well-designed 6.5" model (no wave guide). Anyhow, as I said, this is a complicated issue and we still have a lot to learn about the practical impact of differing dispersion patterns (both horizontal and vertical) and possible colorations introduced by wave guides.

 

[thewas]

My invitation stands.

So does mine, there is only a "tiny" problem, we live several thousand miles away.

Things get dicier with an 8" driver. I've designed a couple that sounded pleasing on their own, but did suffer in comparison to a well-designed 6.5" model (no wave guide).

The discussion here was about the 8" HD1 and you now admit yourself that you haven't heard one that sounds as good as a 6,5" one without WG which is a strong indication that the larger directivity mismatch is the reason.

 

[617]

This is a complicated subject, and generalizations are dangerous. The cosmic issue is whether very well controlled directivity at wide angles is as important as often maintained. Even Floyd Toole says it's the "icing on the cake," and that early arrivals are what really establish the tonality and quality of a speaker. That has certainly been my experience. I would rather listen to a 6.5" speaker with an off-axis dip in the crossover region but wide dispersion in the highs, than a speaker with a smooth but monotonically declining response. The Harman group offers the best engineered wave guides, and I don't doubt that the higher end models avoid the problems I'm hearing in less expensive 2-ways. (That may be because they're mostly 3-ways that don't run the tweeter as low as in a 2-way.) But even the Revel I have here suffers from the tell-tale cupped coloration I'm hearing in all of the less expensive 2-way wave guide brands, although to a much lesser degree. The speaker I would offer for comparison has a $17 6.5" woofer and a $15 dome, both Parts Express Dayton models, crossed at 1900 Hz. The tweeter flange is flat with no horn loading and has wider dispersion than other models with contoured flanges. I prefer it--you might or might not--but I don't think there's a scientific bass for dismissing a 6.5" speaker out of hand because it doesn't use a wave guide. Things get dicier with an 8" driver. I've designed a couple that sounded pleasing on their own, but did suffer in comparison to a well-designed 6.5" model (no wave guide). Anyhow, as I said, this is a complicated issue and we still have a lot to learn about the practical impact of differing dispersion patterns (both horizontal and vertical) and possible colorations introduced by wave guides.

I agree with you up to the description of a cupped coloration. I find the shallower waveguides give better intelligibility at the expense of atmosphere. Baffle mounted tweeters give another sort of treble presentation.

My point is that if you want wide dispersion, you should go all the way...small mid like a bmr or dome, small dome tweeter like a hiquphon or seas 22mm. And that type of speaker I will always advocate for. That's the audiophile sound, for me.

Waveguide speakers I like for home theater and near field but for good music recordings I will take the wide dispersion speaker every time.

I will definitely concede that with the proliferation of detailed sonogram graphs I have assumed that reducing directivity error at all costs is desirable but I am coming around. I think in room tonality, dynamics and treble dispersion are more important past a certain point of DI smoothness. And treble dispersion is subjective.

Regarding ammo inch 2 way... This is a topology I've always wanted to see perfected since 8 inch woofers nowadays can give serious bass, and for this use a waveguide is definitely desirable.

 

[Dennis Murphy]

"I agree with you up to the description of a cupped coloration. I find the shallower waveguides give better intelligibility at the expense of atmosphere. Baffle mounted tweeters give another sort of treble presentation."

Someone just posted high resolution spins of the M16, and I think they support my description of the sound, although it looks like the wave guide just isn't working very well, rather than there being a mysterious coloration introduced by the shape of the guide itself.

 

[aarons915]

It seems odd that these discussions always veer into a debate about how wide of dispersion we want but to me the biggest benefit of a properly designed waveguide is how well integrated the drivers are. Real sounds mostly come from a single point in space so it seems logical that we would want our speakers to be as close to that ideal as possible. Wide dispersion doesn't seem to matter that much when using at least 2 speakers at a time so I'm not sure why we prioritize that over other aspects of speaker design.

 

[Dennis Murphy]

It seems odd that these discussions always veer into a debate about how wide of dispersion we want but to me the biggest benefit of a properly designed waveguide is how well integrated the drivers are. Real sounds mostly come from a single point in space so it seems logical that we would want our speakers to be as close to that ideal as possible. Wide dispersion doesn't seem to matter that much when using at least 2 speakers at a time so I'm not sure why we prioritize that over other aspects of speaker design.

I think it's more complicated than that. You certainly don't need a wave guide to properly integrate a 2-way over a +/- 30 degree window. It's further off-axis that presents problems, and that's where you get into a trade-off between dispersion and prettier graphs. Plus, wave guides are just difficult to get right. Finally, I'm not understanding your comment about wide dispersion not mattering when using at least 2 speakers. That's when it matters most. With only one speaker playing, wide-dispersion speakers don't have any particular advantage over narrower dispersion designs, and may in fact sound less focused.

 

[aarons915]

I think it's more complicated than that. You certainly don't need a wave guide to properly integrate a 2-way over a +/- 30 degree window. It's further off-axis that presents problems, and that's where you get into a trade-off between dispersion and prettier graphs. Plus, wave guides are just difficult to get right. Finally, I'm not understanding your comment about wide dispersion not mattering when using at least 2 speakers. That's when it matters most. With only one speaker playing, wide-dispersion speakers don't have any particular advantage over narrower dispersion designs, and may in fact sound less focused.

Maybe but surely a 2-way is the hardest to integrate considering the difference between a midwoofer and tweeter is going to be the largest in that configuration compared to a 3 way? I agree in a +/- 30 degree window it should be fine but even in my small room I estimate my early reflections to be in the 30-45 degree range, in larger rooms I estimate that to be 45-60 degrees.

My comment about wide dispersion not mattering as much with multiple speakers is referring to Toole's mono vs stereo study. It shows that spatial characteristics have a large impact on preference in mono but in stereo those spatial differences largely disappear due to reflections from multiple sources.

 

[aac]

Don't know why you are so obsessed about dispersion if that speaker would probably go into the non-environmental studio room.

 

[Dennis Murphy]

Maybe but surely a 2-way is the hardest to integrate considering the difference between a midwoofer and tweeter is going to be the largest in that configuration compared to a 3 way? I agree in a +/- 30 degree window it should be fine but even in my small room I estimate my early reflections to be in the 30-45 degree range, in larger rooms I estimate that to be 45-60 degrees.

My comment about wide dispersion not mattering as much with multiple speakers is referring to Toole's mono vs stereo study. It shows that spatial characteristics have a large impact on preference in mono but in stereo those spatial differences largely disappear due to reflections from multiple sources.

Unfortunately, my copy of Toole was last seen in a hotel room in Norman Oklahoma. Do you know what the 3 speakers are? Was one a truly wide dispersion design like the BMR?

 

[aarons915]

Unfortunately, my copy of Toole was last seen in a hotel room in Norman Oklahoma. Do you know what the 3 speakers are? Was one a truly wide dispersion design like the BMR?

None of them were as wide as the BMR but 2 weren't bad. I'll just post the speakers and their measurements. I don't think it really matters how wide the dispersion is, the important thing from the previous picture I posted are how the spatial quality and sound quality ratings drastically go up when BB goes from mono to stereo. BB is an electrostatic speaker and you can see the measurements are much narrower then the other 2 speakers yet simply adding the 2nd speaker basically puts all 3 around the same level of perceived spaciousness. I've said for years that I haven't really noticed a big difference between the dispersion of speakers with 2 or more playing and this study seems to back that up.