[MarkParity]

I had a thought, since Chord does not do firmware updates for their DACs, for security reasons. Would it be possible to update the DAC via Poly?

No there is a connector on Mojo's circuit board for this purpose. Software from XILINX is available, as is the programming lead but unless Chord provide the new image to program onto the FPGA there wouldn't be a lot of point in spending money for the software and lead.

 

[Guy Fawkes]

No there is a connector on Mojo's circuit board for this purpose. Software from XILINX is available, as is the programming lead but unless Chord provide the new image to program onto the FPGA there wouldn't be a lot of point in spending money for the software and lead.

One thing I really wish had been possible is to reprogram the 4 EQ bands. I love the quality of the Mojo2's EQ but I think the two dip EQs at 20Hz and 20Khz are a bit useless and the two shelf EQs are not always suitable, especially the low shelf at 150hz often tends to invade the mid-low range too much and make the sound muddy.

I would have loved to have 2 low shelves at 100Hz and 400Hz for better control of the bass and low mids and 2 high shelves at 1.6Khz and 6.4Khz for perfect control of the upper mids and highs. In this way I would have obtained concrete control over the entire range... too bad, however, that this is not possible

The idea is this:

Red: Low Shelf 100Hz - Q 0.7
Yellow: Low Shelf 400Hz - Q 0.7
Green: High Shelf 1600Hz - Q 0.7
Light Blue: High Shelf 6400Hz - Q 0.7

The band numbers are multiples of the first band, this kind of approach works well when using shelf filters

@Rob Watts What do you think should be implemented in future projects?

 

[Hypops]

One thing I really wish had been possible is to reprogram the 4 EQ bands. I love the quality of the Mojo2's EQ but I think the two dip EQs at 20Hz and 20Khz are a bit useless and the two shelf EQs are not always suitable, especially the low shelf at 150hz often tends to invade the mid-low range too much and make the sound muddy.

I would have loved to have 2 low shelves at 100Hz and 400Hz for better control of the bass and low mids and 2 high shelves at 1.6Khz and 6.4Khz for perfect control of the upper mids and highs. In this way I would have obtained concrete control over the entire range... too bad, however, that this is not possible

The idea is this:

Red: Low Shelf 100Hz - Q 0.7
Yellow: Low Shelf 400Hz - Q 0.7
Green: High Shelf 1600Hz - Q 0.7
Light Blue: High Shelf 6400Hz - Q 0.7

The band numbers are multiples of the first band, this kind of approach works well when using shelf filters

@Rob Watts What do you think should be implemented in future projects?

I've spent some time approximating the Mojo 2's EQ settings in REW (in order to find ideal settings for my various headphones) and have found that your proposed 400Hz and 1600Hz shelves are actually pretty close to the actual values if you recreate the same shelf filters using PEQ. The "125Hz" and "3kHz" values are actually the points where the boost/cut hits maximum rather than the values you would use on a PEQ.

As for your suggestion that we use additional shelves rather than peak filters for the lowest and highest ends, it amounts to more or less the same thing. The 20Hz and 20kHz filters are pretty wide when approximating their Q values using PEQ (~0.5), so they already work like shelves IMO.

I dunno. I've really come around on the Mojo 2's (initially odd-seeming) EQ setup. Like I said earlier in the thread, it's more like a 4-band loudness knob rather than a 4-band GEQ.

 

[Guy Fawkes]

The low shelf of the Mojo 2 is not at 125hz but at 150hz and the high shelf is at 2400hz not at 3000hz, i don't know why it was advertised at 125hz and 3000hz but I assure you that those are not the correct values.

With the low shelves at 100hz and 400hz you get perfect control of the low and mid-low range, even 125hz and 500hz can work, the important thing is that you use multiples of the first band (100 x 4 = 400) in this way you get control over the 100hz, 200hz and 400hz frequencies.
Continuing upwards we have 800hz which is the central point and then up again it continues in multiples with two other high shelves at 1600hz and 6400hz, with this system you obtain control over the 1600hz, 3200hz and 6400hz frequencies.

however, a solution with:

Red: Low Shelf 125Hz - Q 0.7
Yellow: Low Shelf 500Hz - Q 0.7
Green: High Shelf 2000Hz - Q 0.7
Light Blue: High Shelf 8000Hz - Q 0.7

can also work very well.

Up until 10 years ago I was involved in mixing, which is why I know these things.

As regards the current two peak filters at the two extremes of the band, I must correct you because in reality they have a Q of 0.7 and not 0.5 and therefore have very little effect.

 

[Hypops]

The low shelf of the Mojo 2 is not at 125hz but at 150hz and the high shelf is at 2400hz not at 3000hz, i don't know why it was advertised at 125hz and 3000hz but I assure you that those are not the correct values.

With the low shelves at 100hz and 400hz you get perfect control of the low and mid-low range, even 125hz and 500hz can work, the important thing is that you use multiples of the first band (100 x 4 = 400) in this way you get control over the 100hz, 200hz and 400hz frequencies.
Continuing upwards we have 800hz which is the central point and then up again it continues in multiples with two other high shelves at 1600hz and 6400hz, with this system you obtain control over the 1600hz, 3200hz and 6400hz frequencies.

however, a solution with:

Red: Low Shelf 124Hz - Q 0.7
Yellow: Low Shelf 500Hz - Q 0.7
Green: High Shelf 2000Hz - Q 0.7
Light Blue: High Shelf 8000Hz - Q 0.7

can also work very well.

Up until 10 years ago I was involved in mixing, which is why I know these things.

As regards the current two peak filters at the two extremes of the band, I must correct you because in reality they have a Q of 0.7 and not 0.5 and therefore have very little effect.

Specific values aside, I'm not sure what this would accomplish that the current EQ doesn't already do. Short of implementing a full-blown PEQ, there's no way to please everyone. And even then, people would complain that it sacrifices too much of something else. As a designer, you have to plant your flags somewhere. I applaud the device for sticking to its (unorthodox) choices.

 

[trickyRoadsDummyTOOL]

I do very much enjoy my Mojo2, sound quality from 2 direct outputs, EQ, crossfeed, physical robustness. No complaints so far. I had to put away my very well working RNHP, to experience what everyone was aware of in advance: RNHP imo is not capable of not masking parts of the information and capabilities mojo2 provides (my dad always said "get rid of this damn amp, I tell you, it is not necessary!", me: "I am aware of that!").
But I have to come back to using an amplifier because I'm/the amp-device is in serious need of:
Hardware remote control
a stable physical link to my streamer/DAC(MoJo2/poly) in order to my streamer/DAC not being pulled over my desktop
a pre-amplifier
future upgradability to power-hungry headphones
Being transparent enough to not mask any information or capabilities my Mojo2 provides
Elsewhere/in another thread I was recommended upgrading my headphones first, but here is my question: are you aware of an Headphone-amplifier covering these prerequisites? Any help/Advice is very appreciated!

 

[Rob Watts]

One thing I really wish had been possible is to reprogram the 4 EQ bands. I love the quality of the Mojo2's EQ but I think the two dip EQs at 20Hz and 20Khz are a bit useless and the two shelf EQs are not always suitable, especially the low shelf at 150hz often tends to invade the mid-low range too much and make the sound muddy.

I would have loved to have 2 low shelves at 100Hz and 400Hz for better control of the bass and low mids and 2 high shelves at 1.6Khz and 6.4Khz for perfect control of the upper mids and highs. In this way I would have obtained concrete control over the entire range... too bad, however, that this is not possible

The idea is this:

Red: Low Shelf 100Hz - Q 0.7
Yellow: Low Shelf 400Hz - Q 0.7
Green: High Shelf 1600Hz - Q 0.7
Light Blue: High Shelf 6400Hz - Q 0.7

The band numbers are multiples of the first band, this kind of approach works well when using shelf filters

@Rob Watts What do you think should be implemented in future projects?

I really welcome suggestions for EQ - but as @hypos said, you can't please everyone. The settings for the shelf and peak were determined so that one could compensate for a first order response for bass - a lot of Japanese IEMs have a first order roll-off at 125Hz, and with the appropriate bass shelf and 20Hz peak control you can compensate for that. And yes, this is a worst case scenario, but then how else can you objectively define an EQ requirement that covers most areas but that is also easy to set-up. 99% of Mojo 2 users don't have a clue as to what Q is - and nor should they need to know. Simple to use, but being able to have max functionality is the name of the game here. Judging by peoples comments on this thread I think the settings are the optimum ones.

 

[HiFiHawaii808]

I really welcome suggestions for EQ - but as @hypos said, you can't please everyone. The settings for the shelf and peak were determined so that one could compensate for a first order response for bass - a lot of Japanese IEMs have a first order roll-off at 125Hz, and with the appropriate bass shelf and 20Hz peak control you can compensate for that. And yes, this is a worst case scenario, but then how else can you objectively define an EQ requirement that covers most areas but that is also easy to set-up. 99% of Mojo 2 users don't have a clue as to what Q is - and nor should they need to know. Simple to use, but being able to have max functionality is the name of the game here. Judging by peoples comments on this thread I think the settings are the optimum ones.

11 band parametric EQ would make Mojo 3 worth double to me as long as you get rid of the USB Micro cables. Warm up the tonality and make it sound a little less digital and it would double it again.

 

[Kentajalli]

11 band parametric EQ would make Mojo 3 worth double to me as long as you get rid of the USB Micro cables. Warm up the tonality and make it sound a little less digital and it would double it again.

Well we are all different, aren't we.
There are two hard attitudes towards EQ:
- Those of us who don't like it.
( Includes me and I believe Rob!)
- Those of us (you!) who must EQ! there are no headphones that do not benefit from EQ. Specially sophisticated, multi-band ones to smooth out every peak and trough.
(actually more than half of Headfi contributors, last time I counted)

What both groups fail to agree is the fact that EQ is half science, half preference! A gentle EQ to correct an overt deficiency of a headphone to taste is OK.
But how can sharp peaks or troughs in frequency response, which are mostly due to resonances or diaphragm breakups, be corrected with sharp multi-band EQ systems??

 

[Jerome Howard]

Just for fun I maxed out all of the EQ on my Mojo 2 and listened with my Stealth Anandas.

Guess what? It sounded great at lower volumes. It reminds me of the LOUDNESS settings on vintage solid state receivers and amps.

 

[Guy Fawkes]

But how can sharp peaks or troughs in frequency response, which are mostly due to resonances or diaphragm breakups, be corrected with sharp multi-band EQ systems??

It would be possible, but it makes the situation worse, better not to touch too narrow dips and peaks

 

[Hypops]

But how can sharp peaks or troughs in frequency response, which are mostly due to resonances or diaphragm breakups, be corrected with sharp multi-band EQ systems??

So true. Still amazing to me when I see people applying EQ trying to chase treble peaks/troughs. Not only are most of those rises and dips uncorrectable, but they also move with just slight shifts in headphone fit, and sometimes they move just because measurement rigs still aren’t great with getting consistent treble measurements.

The more I learn and experiment with EQ, the more I see a solution like the Mojo 2’s EQ is wisely conservative. I still prefer PEQ, but my approach isn’t all that different from what the Mojo 2 offers.

 

[daveya]

Most Mojo owners will just see the word bass in the instructions and add a bit, if they like bass, same with treble, that's as complex as it gets

 

[Kentajalli]

It would be possible, but it makes the situation worse, better not to touch too narrow dips and peaks

If it makes the situation worse, then it is Not possible to correct them.
Yet on your first sentence you declare it is possible.
Is that a contradiction I detect?

 

[econ83]

Hey guys - I got a brand new Poly streamer for my mojo2, but I don’t seem to have the option to use it as a streamer (missing Roon, and “other music services” in the settings). Has anyone seen this before? Anyone know a fix? It came with Firmware V3.2.1 out of the box.