Theoretically they could do as steep/drastic Q settings as MP EQs.
But the more ringing you have (which is exactly what's happening for steeper curves [and lower frequencies]), the more predelay/latency you need with LP EQing.

So the level of steepness is limited by the latency an LP EQ introduces. Some LP EQs offer different settings because for that (PSP Neon for example .. or PLParEQ), so you can select higher latencies, if you want to do steeper EQing.

Hi!

Just to "bump" this thread ...

Today I used the Voxengo Marvel EQ for mastering 3 songs - basically percussion, bandolim, 7 strings ac guitar and voice. No bass or bass drums, then, little response below 100hz.
Then, used it basically for frequencies above 120Hz .It behaves in a very natural way - mix was in the "harsh and thin" side.It really shines on M/S mode , which (at least in my experience) usually sounds weird on MP eqs. Very precise on the higs also, sweetening some harshness in a very "elegant"way . Big Thumbs up

And the processor barely hits 2%, and that for a linear phase EQ is rather spiffing dont you think. Its one of the best free EQ's on offer, I use it on drums when I am after a really natural and nuetral colour with out all the phase shift and phase distortion that can occur. In all the times ive used it I have yet to hear the dreaded warping sound that can occur around the mid frequencies
due to linear phase filters. Yup, this is another must have EQ- well it is for me anyway, I use it more than all the other payware linear phase EQs I have, mostly down to the processor hit thats next to nothing

I also own the DDMF LP10, and, while it sounds great for narrow cuts on MP (it's my main eq for this purpose), I prefer to not use it in Linear Phase - narrow cuts on low frequencies and the terrible pre ringing effect on things like bass drum that can seriuouly affect a master/mix unless you know what you're doing.

What I see (by ear, of course, but also analyzing it in the VST analyzer), is that the Q is never narrow in the Marvel eq, the filters on lows are very subtle/wide - looks like it always work in a "safe mode" to prevent pre ringing ?

I think voxengo man set it at the best specific Q he found, but either way it does what it does very well. The ringing sound is dreadful when you start making extreme boosts with wide q. In the Vox curve Eq (version 2) there is 2 linear phase modes and 1 minimal which affect the way it works, one significantly reduces the warping around the 1 khtz freq range. It also has settings where you can change the amount of the filter kernels which then in turn affect the way the EQ sounds, for creative or mix specific processing. I preferred version 2 because it had a master saturation feature and about 30-40 impulse responses built into it taken from high end Analog Gear such as tape machines and Tube EQ's. With version 3 he stripped away all the best features and just made it a matching freq linear phase EQ. version 2 is far superior to version 3 for features. Also the sound of the EQ is the best I have come across, and now that processing power is up to spec it reads about 4% on a quad core AMD with 3GB RAM. On a standard dual core or lower it would range between 20-30%. Its one of my treasured little EQ's that doesn't get as much attention as it should since Ive bought a lot of new ones(IK tracks linear phase EQ) that
just do the same thing. its funny how you keep buying things over and over again just because you feel compelled to stay with the fore running technology. When all is said and done some of the differences are so insignificant its just down to how the sound has changed microscopically, which in turn did not justify all the spending i have done. I own nearly all Voxengo products from version 2 and have upgraded most of them. However i have noticed he has made some better and some not as good as the original, apart from a new user interface and streamlines the FX so they are easier to work with. Im really impressed with the voxformer upgrade because its now a proper complete channel strip with really smooth sounding dynamics that are not too far off IK's fairchild emulation. I also noticed he has implemented linear phase oversampling on all his DSP fx as standard. Only problem is the processor hits are between 15-60%. Soniformer has such a sound and warmth to it i find it incredible, especially since he has simplified it but the processor easily hits 65% without oversampling engaged. Im happy enough with the computer ive got because its all I need for the moment, but to stay on topic, Voxengo's FX are like marmite.. you will either love them or loathe them. Really powerful tools but take some learning at first. If you like Marvel EQ give his others a demo.
Trakstar