At least before they used the Seas LROY 10" which is both a capable driver and well suited for a small sealed enclosure.
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GRIMM Audio LS1c & SB1 DSP Speaker Review
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markk
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Indeed. for $40k, seems like they could have put in two ROY's a side. Anyway, I'm not going to pile it on the design choices any more. Since the perception of bass is determined more by the nature of the reverberant sound field, I'm sure the bass would be acceptable...in the right room.
Not entitled, do you think musical overtones contained in the program, filling up all the bits to full scale of the digital medium, are ‚distortion‘? I‘m a rare bird, me thinks.
All that interesting facets of the LS1 are drowned in bass. (Sic!) There was so much valuable input from professionals in the field What if a quality speaker is put into a densly packed bookshelf? The Harman tilt, bass v/s mids sounding lean? Not the least, when questioning the measurement method, I’m tempted to address the ripples in lower mids first. It is a pitty.
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How do you define max SPL?
Most of the time you measure and raise the level until you find a certain maximum distortion level.
If the feedback loop reduces that distortion you can raise the level further until you find that same maximum distortion level.
So: max SPL increased!
MattHooper
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Here is the step response measurement taken by Stereophile of the Grimm speakers:
I have a question about a time phase coherent step response like this.
I’ve long owned Thiel speakers which have attempted to produce time phase coherence in the analogue domain via the first order crossovers, etc.
When measuring the Thiel speakers John Atkinson remarks that it is a bit finicky to orient the microphone to obtain the correct time, phase coherent, step response. The microphone has to be at the right height, for instance (34” for the 3.7s) and no doubt the correct distance.
With the active phase, coherence represented above in the Grimm speakers, does this mean that they are less finicky about where they cohere to a good step response like that? Will there be any more latitude to distance, listening height, off axis etc where the listening would still get that step response as opposed to the analog version of a Thiel speaker ?
I have a question about a time phase coherent step response like this.
I’ve long owned Thiel speakers which have attempted to produce time phase coherence in the analogue domain via the first order crossovers, etc.
When measuring the Thiel speakers John Atkinson remarks that it is a bit finicky to orient the microphone to obtain the correct time, phase coherent, step response. The microphone has to be at the right height, for instance (34” for the 3.7s) and no doubt the correct distance.
With the active phase, coherence represented above in the Grimm speakers, does this mean that they are less finicky about where they cohere to a good step response like that? Will there be any more latitude to distance, listening height, off axis etc where the listening would still get that step response as opposed to the analog version of a Thiel speaker ?
It depends mainly on the distance between the drivers leaving a noticeable footprint in the step response, so first and foremost tweeter and midrange. A delay of 0.05ms which would already produce two separated steps on the graph equals a delta of 1.7cm of distance microphone<>driver.
The way spikes of different drivers shift between each other on the step response graph, is mainly a geometrical issue and not related to the type of x-over and electrical phase correction used. The main difference digital x-over designs introduce is that they can provide a true delay, very steep filters and with the help of FIR filter even a linear phase behavior independent from frequency. In practice the influence on the step response graph should not be overestimated. If anything, it would lead to a better separation of the driver´s footprint hence they would be slightly more finicky regarding positioning the mic.
It is impossible to answer that as the main influencing factors are driver geometry and x-over slope. Jim Thiel was using mainly 1st order crossorder filters while DSP controlled active concept can use pretty steep filters.
I would not overstate the importance of the step response at the listening position. Human ears are not really good in discriminating inner phase shift, and what looks like a ´signal torn apart´ on the step response might not be audibly different from a variant with a perfect step.
olieb
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This seems an overgeneralisation to me. Lets look at the example at hand (LS1) and your case of time misalignment.
I did compare the step responses for aligned and misaligned tweeter (±0.05ms).
In the first picture the red is the step response for the FR of a (perfect) speaker with LR2 70Hz high pass, like the LS1 upper box with a perfect linearisation of the crossover phase at 1550Hz LR4.
Green and blue are the same but for the tweeter being 0.05ms early and late.
The second shows the same but with the phase of the crossover not linearised.
Wouldn't you agree that the phase correction has the more significant influence on the visuals of the step response?
Actually the phase distortion from the LR4 at 1550Hz creates a step response that looks similar to a time misalignment of the (linearised) drivers of 0.15ms≈5cm. The difference in those two cases is that the misalignment would create a 3dB dip in the FR at 1550Hz.
There seemingly was a misunderstanding. I was referring to the relative shift of spikes in the diagram after the ideal step has already been achieved at some position in the room, this or that way. This is independent from some crossover types either allowing or not allowing coherence. You are completely right on that matter.
@MattHooper ,
that's a steep cliff! But you can also see that it has a foot on the left, something must have crumbled off there. So far it doesn't fit with the "coherent" no matter what.
Also take a look at the bandwidth of audio signals. that's several decades. I don't know how much of an engineer you are, but wouldn't it make sense for a representation like the one you're probably aiming for here to have a logarithmic time axis?
All these deficiencies in the representation show to what extent what can be seen must actually be irrelevant. It's nonsense, to be honest. It's supposed to create a wow effect, but (critical) insight is hardly the goal.
On the technical side: it's about the distance of the ears (!) from the different speakers of a loudspeaker. if the speakers are lined up vertically as usual, then the distance to the individual speakers changes depending on the height of the ears - for purely geometric reasons. Now you can create such beautiful images as shown for a single point in the room, but if you deviate in height by just one iota, then the whole thing disintegrates into nothing.
So, in all human wisdom, it is probably only gross nonsense to invest tricks and trickery in throwing everything onto the one point.
Do you know what's missing? A clear vision of what the whole thing is for. The advertising draws customers into technical debates that subsequently turn out to be BS. Well, it's been doing that for decades.
These same three drivers put in a conventional box and married to a solid passive crossover design would yield 99% of the audible performance of the Grimm. For a LOT less money!I'm a one hit wonder!
sorry, bad link...
Boy, that was a long time ago! Anyway, I'm retiring soon from the career that kept me from doing more building, so expect a project or two after a 15 year hiatus! With more bass...
Mark K
This goes to show the excesses and pie-in-the-sky objectives that some in the hi-fi industry have aimed towards.
Good engineering is getting the job done with the least cost and solid reliability. The Grimm LS1 is not that.
This could be your return-to-action project, Mark!
Pearljam5000
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Why not make it a 3-way by adding a coaxial driver instead of just the tweeter?
sure....These same three drivers put in a conventional box and married to a solid passive crossover design would yield 99% of the audible performance of the Grimm. For a LOT less money!
This goes to show the excesses and pie-in-the-sky objectives that some in the hi-fi industry have aimed towards.
Good engineering is getting the job done with the least cost and solid reliability. The Grimm LS1 is not that.
This could be your return-to-action project, Mark!
My premise wasn't flippant. 'Certainly achievable, in my opinion. (30-40 years ago I was DIY'ing systems just like that.)
Much depends upon the objective. Mine is to have a system where at the end of the day I can sit and enjoy listening to Mozart, or Supertramp, or whatever....and not spend a mint doing it.
If you get into this biz and your objective is to display your ego and products at the Munich Audio Show......maybe you have a different objective.
Because that would be another speaker. Not only in principle, but from the visual appearance also. And I think, the iconic shape of the LS1 is a crucial part of the whole story. It shows retro ingenuity, very much more than the other fancy stuff, think of Wilson Audio, and not the least it is real.
From an objective point of view, a three way would have been better, 8" + 6" + 1"/small waveguide. The low cross-over point of the tweeter is very important, so that a coaxial is not needed for sufficiantly smooth and wide vertical dispersion.
It should be very clear that 80% is payed for the looks and the ready made solution combined. I don't need that, actually. I drive a pre-owned 23y old car also - because I just came to like it. Would I spend the spared money on LS1? Nope.
I think you underestimate the amount of scientific and technical work and energy put in this design by Grimm Audio to get to this result.
No, absolutely I don't.
I think you overestimate how much subjective and objective performance all that scientific and technical work actually delivers.
This thread is populated by people raising their eyebrows at some aspects of the performance of this system. And also the value (for the money) of it.
I can to some extend agree that the price/performance ratio is questionable.
But saying that putting the same drivers in passive solution would give easily 99% of this results is underestimating the real work involved.
I'm not talking about the work involved.....I'm talking about the result. I thought that was obvious.
But, believe what you want to believe.
Who said anything about fulfilling the same "requirements"??
My only premise was using the same three drivers.
You fellas are reading between the lines and getting tangled up in whataboutism.
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