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GRIMM Audio LS1c & SB1 DSP Speaker Review

Rate this speaker system:

  • 1. Poor (headless panther)

    Votes: 10 3.1%
  • 2. Not terrible (postman panther)

    Votes: 20 6.3%
  • 3. Fine (happy panther)

    Votes: 115 36.2%
  • 4. Great (golfing panther)

    Votes: 173 54.4%

  • Total voters
    318
That's true, but if you're gonna use some RoomEQ then you don't really want the bass rolling off because you can use the extra bass (from the linear extended bass of other speakers) along with room gain to EQ up the dips (so to speak) by just cutting the peaks, so the argument for rolled off bass is only really useful if you're not gonna be using somekind of RoomEQ.
I should think that it doesn't matter one way or the other. The bass shelf is not caused by a limitation of the speaker, but is rather deliberately implemented. The amount of headroom available in the speaker at those frequencies hasn't changed, so you should be able to achieve the same result post-room equalization.
 
Nope. Do you think an FFT is a simulation of a real time analog signal? That is also a computed result based on time domain samples and subject to variation by picking its length.

To the extent FFT finds the basis sine waves, NFS finds the (3-D) Henkel functions to describe the sound field. Neither it, nor FFT computation fall in any kind of simulation domain. Just because complex computations are needed to convert sample data to graphs that we like to see (understand), doesn't mean the result is simulated.

Now, if you took some hand created data and fed it to NFS, sure, that would be a simulation. But that is not the case. NFS in my measurements uses 1000 to 2000 sweeps to compute its final results. The data presented is simply the 3-D representation of that 2-D data.
Master Yoda throwing in some "knowledge" where it matters :)
 
I dont know if it is mentioned but the sub has current amplifier and accellorometer in the feedback loop. So this is a quite complicated design. But grim are very open on their design desicions.
 
Klippel measurements have been corroborated by more traditional methods multiple times and found to be accurate.
In direct comparison the LS1s never had the weight or bass extension of say the 8Cs, I thought of them more suitable for the classical listener.
Keith
You're definitely not a classical listener, right?
Classical without meat by the gear is probably the reason some people don't like it.

Yes, lows and mid-lows needs to be clean and tight, not thin and non-existent.
 
Master Yoda throwing in some "knowledge" where it matters :)
Master Yoda avoids to answer if he even tried to setup speaker parameters via LS1 Software Control? If he did why there are no measurements of different setups? Like in that snake-oil catalog Stereophile? Why are ASR measurements of LS1 so different then every other published LS1 measurement, but other loudspeakers have similar measurements?
 
The feed-back of the sub, is that the same as Karl-Erik Ståhls ACE-Bass?

Synthesis of Loudspeaker Mechanical Parameters by Electrical Means: A new Method for Controlling Low-Frequency Loudspeaker Behaviour; 1 November 1978; Journal of The Audio Engineering Society.
 
Master Yoda avoids to answer if he even tried to setup speaker parameters via LS1 Software Control? If he did why there are no measurements of different setups? Like in that snake-oil catalog Stereophile? Why are ASR measurements of LS1 so different then every other published LS1 measurement, but other loudspeakers have similar measurements?
You can blame that on Grimm.

Grimm_LS1.png
 
I should think that it doesn't matter one way or the other. The bass shelf is not caused by a limitation of the speaker, but is rather deliberately implemented. The amount of headroom available in the speaker at those frequencies hasn't changed, so you should be able to achieve the same result post-room equalization.
Well, we don't really know what the headroom is of the "subwoofer" section, because the dB levels that Amir measured are based around 1kHz dB levels and the bass is rolled off below that point at lower SPL's therefore the distortion measurements in the bass aren't representative of if you EQ'd up the bass to make it linear with the rest of the response. I suppose you could try to extrapolate it, I'll try:

So first how much is the bass rolled off at different points:
  • 70Hz is -3dB;
  • 60Hz is -4dB
  • 50Hz is -5dB
  • 40Hz is -6dB
  • 30Hz is -10dB
  • 20Hz is -16dB
So for Amir's distortion results if you want to use EQ to boost the bass to Anechoic Flat at the various points, then to get 30Hz anechoic flat then you need to boost by 10dB which means you have to look at the 96dB distortion results (96dB distortion.jpg) rather than the 86dB distortion results, which means at 30Hz you have distortion at nearly the same level as the fundamental which is rubbish performance. Looking at another point 40Hz is 6dB down, so you'd have to EQ 40Hz up by 6dB, so looking at the distortion percentage results you'd probably be taking the 86dB performance graph and forcing the distortion off the scale of the following graph at 86dB: 86dB & 96dB Distortion.jpg
Whereas a speaker like the Genelec 8361A is already anechoic flat at 40Hz and is outperforming this speaker re distortion:
Genelec 8361A distortion.jpg

So really, in conclusion I don't see this speaker having any significant bass headroom that you mention, at least not for the price. The Genelec is just $4995 in comparison and doesn't even have a seperate "subwoofer" yet still outperforms it. The roll off in the bass of this speaker is not a positive if you're gonna be using RoomEQ and it's not like this speaker has loads of headroom down low, I don't think it has much headroom down there at all.

EDIT: and as one more example you've got the JBL 708p for $1800 and that's flat down to 50Hz (JBL 708p Distortion.jpg) and again outperforming re distortion, so the Grimm Audio speaker is not doing much right in the bass and certainly not for the price!
 
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Master Yoda avoids to answer if he even tried to setup speaker parameters via LS1 Software Control? If he did why there are no measurements of different setups? Like in that snake-oil catalog Stereophile? Why are ASR measurements of LS1 so different then every other published LS1 measurement, but other loudspeakers have similar measurements?
Look, @amirm (Master Yoda) and I don’t exactly see eye to eye, so this isn’t about loyalty or friendship and I also didn't follow up the matter in discussion in detail but I have zero reason to doubt his integrity or the way he runs his measurements. He’s consistently challenged the biggest names in audio without fear in the past, and that kind of courage speaks volumes IMO.
 
Well, we don't really know what the headroom is of the "subwoofer" section, because the dB levels that Amir measured are based around 1kHz dB levels and the bass is rolled off below that point at lower SPL's therefore the distortion measurements in the bass aren't representative of if you EQ'd up the bass to make it linear with the rest of the response. I suppose you could try to extrapolate it, I'll try:

So first how much is the bass rolled off at different points:
  • 70Hz is -3dB;
  • 60Hz is -4dB
  • 50Hz is -5dB
  • 40Hz is -6dB
  • 30Hz is -10dB
  • 20Hz is -16dB
So for Amir's distortion results if you want to use EQ to boost the bass to Anechoic Flat at the various points, then to get 30Hz anechoic flat then you need to boost by 10dB which means you have to look at the 96dB distortion results (View attachment 452904) rather than the 86dB distortion results, which means at 30Hz you have distortion at nearly the same level as the fundamental which is rubbish performance. Looking at another point 40Hz is 6dB down, so you'd have to EQ 40Hz up by 6dB, so looking at the distortion percentage results you'd probably be taking the 86dB performance graph and forcing the distortion off the scale of the following graph at 86dB: View attachment 452909
Whereas a speaker like the Genelec 8361A is already anechoic flat at 40Hz and is outperforming this speaker re distortion:
View attachment 452911

So really, in conclusion I don't see this speaker having any significant bass headroom that you mention, at least not for the price. The Genelec is just $4995 in comparison and doesn't even have a seperate "subwoofer" yet still outperforms it. The roll off in the bass of this speaker is not a positive if you're gonna be using RoomEQ and it's not like this speaker has loads of headroom down low, I don't think it has much headroom down there at all.
In this case they must be the greatest liars in the history of HiFi:

Grimm.PNG


If 400W produces that much distortion at a decent driver, even at the edge of its response it must either be the cheapest on the planet or broken.
That's on top of the absurd +16dB added stated response at 20Hz!
 
In this case they must be the greatest liars in the history of HiFi:

View attachment 452912

If 400W produces that much distortion at a decent driver, even at the edge of its response it must either be the cheapest on the planet or broken.
That's on top of the absurd +16dB added stated response at 20Hz!
Didn't I read a post earlier that said they haven't done anechoic measurements of their speaker, or at least the specs are based on an in room estimate (don't quote me), but that sounds like a shady way of doing it, either way if we take Amir's anechoic measurements to be accurate then it's not looking great for this speaker re it's bass performance, and would indeed shed doubt on the manufacturer's quoted specs.
 
Audio magazin measured -3dB @17Hz, 105dB max SPL (100dB without compression), 10%THD @30Hz & 100dB

View attachment 452916
That must be with room reinforcement right though, re the -3dB @17Hz? So that part can be ignored, but the distortion measurement should be valid at that point albeit you wouldn't expect it to be just -3dB at 17Hz. Looks like Amir got somewhat worse distortion measurements, I've not quantified it exactly.
 
if you're gonna use some RoomEQ then you don't really want the bass rolling off because you can use the extra bass (from the linear extended bass of other speakers) along with room gain to EQ up the dips (so to speak) by just cutting the peaks, so the argument for rolled off bass is only really useful if you're not gonna be using somekind of RoomEQ.
Not necessarily true for a ported configuration like that Revel. A flat response would require a higher tuning frequency (assuming the same drivers). Since it's generally a very bad idea to apply boost below the port tuning frequency, a lower tuning with a somewhat shelved response may result in better in-room bass extension while keeping excursion (and distortion) under control.

Note: this doesn't really apply to sealed configurations (like the LS1c and SB1).
 
That must be with room reinforcement right though, re the -3dB @17Hz? So that part can be ignored, but the distortion measurement should be valid at that point albeit you wouldn't expect it to be just -3dB at 17Hz. Looks like Amir got somewhat worse distortion measurements, I've not quantified it exactly.
Judging by other speakers they measure as in @Vuki 's post they seem not to use boundary effects.
After all it's not that close to the floor.
 
Not necessarily true for a ported configuration like that Revel. A flat response would require a higher tuning frequency (assuming the same drivers). Since it's generally a very bad idea to apply boost below the port tuning frequency, a lower tuning with a somewhat shelved response may result in better in-room bass extension while keeping excursion (and distortion) under control.

Note: this doesn't really apply to sealed configurations (like the LS1c and SB1).
Well, I'm not talking about speaker design choices, I'm talking about the actual distortion measurement results when you compare different speakers at any given frequency in the bass, so I don't care how the designer designs their speakers, I'm just talking about the comparative results, it's the results that matter.
 
Judging by other speakers they measure as in @Vuki 's post they seem not to use boundary effects.
After all it's not that close to the floor.
I'm not gonna start saying that Amir measured the speaker wrong, or that there was something wrong with the unit of that speaker that he measured - I just can't know that. I think I've seen Amir challenging various rebuttals on this topic in this thread, and he's confident with the validity of his measurement. The differences are curious, but I can't obviously see what could be wrong if anything with Amir's measurement or speaker unit. But yeah, judging by Amir's measurements, this speaker doesn't perform great in the bass, and certainly not for the money.
 
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