Mooer Speaker Sim / DI - A great little problem solver!

[paulbuzz]

So, here's a problem that I've often been faced with, as have, I would guess, many other bassists:

You want to use overdrive/distortion/fuzz pedals, but your combo or cab has a tweeter, leading to your distorted sounds being all fizzy and horrible, unpleasantly similar to a wasp in a can.

This fizz isn't easily removed by most normal varieties of EQ, as what's required is a really steep rolloff of high frequencies (mimicking the highly-truncated treble response of guitar speakers), and most tone controls on bass amps or mixers just can't emulate this kind of brutal frequency trimming.

Aha, you say (only to yourself, I hope!), I'll just turn the tweeter on my cab right down, and all will be well.
But at least two possible problems arise:

1) Not all cabs/combos have an adjustable tweeter.

2) Your bass also needs to be fed into the PA. The soundman is in a hurry and a bit grumpy, and doesn't want to mic up your cab. He just wants to plug in a DI, like he normally does for basses. So although you've removed the waspfizz from your backline, your chunky bass distortion still sounds buzzy and cheap through the PA.

Enter a handy little solution: the [url="http://www.mooeraudio.com/en/ProductInfo.asp?id=93"]Mooer Micro DI[/url]



This is marketed primarily as a DI box, but there are already plenty of them available. More unusually, it's also a speaker simulator, and it's this aspect of the Mooer box that interested me. There are several other DI boxes that include speaker simulation (from Palmer, Behringer, and H&K amongst others), but this particular box has a combination of features that drew my attention :

1) It's reasonably priced (about £50).
2) It's small (and dangerously close to being cute!).
3) It's powered via a standard pedal-type 9V DC connector, so it plays nicely with your pedal board.
4) The speaker simulation, when switched in, is applied to the jack output as well as the balanced XLR DI output.
This last feature is unusual amongst the DI boxes that include speaker simulation, and means that you can keep your cab's tweeter turned up, and have a clear idea of the signal you're sending to the PA.

There are a few other fairly normal DI box features - a ground lift switch to relieve hum problems, switchable output levels - but it's the speaker sim function I'm mainly interested in here.

So - what does it sound like? Well, subjectively, it does the job pretty much as you might expect and desire - the fizzy top frequencies of distortion sounds are trimmed off, and your favourite distorto-pedal sounds much more like it's supposed to, even when fed into full-range bass cabs or PA speakers.

I was interested to get a more detailed idea of what it was doing, so I did a quick frequency response measurement using RightMark's free Audio Analyser. (Disclaimer: I'm not claiming to have used any super-accurate testing methods - just a quick test to get an idea ). So here's the frequency responses I measured:

[attachment=151899:mooer_ssim.png]

The green line is the Micro DI with the speaker sim turned off; the wobbliness towards the top of the frequency range is an artefact of my mediocre soundcard, so ignore that! Broadly speaking, there's a pretty wide and flat frequency response, as you would expect from any reasonably decent DI box.

More interestingly, the white line shows the speaker simulation circuit response, and as expected, it's pretty heavily reshaped. The important high frequency rolloff starts from about 3 kHz, and is steep as is required - about 20 dB per octave by the looks of it. This is exactly the kind of tone-shaping that really can't be achieved by turning down a generic 'treble' knob.

There's also heavy modification of the low frequency response: relative to the rest of the speaker-sim sound there's a bass boost of around 4dB, centred just above 100 Hz. Additionally, there's a sharp rolloff of lower bass frequencies below about 50 Hz.

This bass-response shaping is, I guess, intending to mimic the response of a generic 4x12 guitar cab, but is not so useful for us bassist-types; the steep bass rolloff would undoubtedly be distressing to earthquake fans and dub exponents, but probably not so problematic in most other scenarios. The generalised bass boost is much more easily modified/countered by a tweak of an EQ control, if necessary.

The closest competitor I could find for this box (in terms of providing a speaker-simulated unbalanced jack output, as well as a balanced DI output) is the A/DA GCS-2, which does also look really good - it has lots more switchable options, but is larger, costs over twice as much, and has a precariously placed knob (stop sniggering) that looks a bit prone to stage damage from the clumsy-footed. A side-by-side sound comparison with the Mooer would be interesting...

So, overall, I think this little box will handily assist in taming the dreaded fizzy wasp sound for me, and perhaps for others too. It's small, reasonably cheap and fulfils a useful role in which it doesn't have much obvious competition. What's not to like?!

[dannybuoy]

Looks good, I play through sealed cabs so not too concerned about the low end roll off - but it would be better for me if the cab sim was switchable so it can be set to only affect the XLR output.

[Wooks79]

[quote name='dannybuoy' timestamp='1389250095' post='2331817']
...it would be better for me if the cab sim was switchable so it can be set to only affect the XLR output.
[/quote]

Same here, if it did that, I'd snap one up!

[paulbuzz]

Danny/Wooks:

If you want the jack signal uneffected, I suppose you could just split the signal before the DI box.

Alternatively, there are various other cab sim DIs that have a straight pass-through jack signal:
[url="http://www.thomann.de/gb/behringer_gi100_ultra-g.htm"]Behringer GI100 Ultra G[/url] (I've got this - works pretty well, but it's so BIG!)
[url="http://www.thomann.de/gb/hugheskettner_red_box_5.htm"]H&K Red Box 5[/url]
[url="http://www.thomann.de/gb/harley_benton_pocket_guitar_di_box.htm"]Harley Benton JDI-01[/url] (So cheap! Haven't tried it though.)

[dudewheresmybass]

I've been using one of these for a few months now, and I am seriously impressed.
I've used it in a variety of settings, and not been disappointed in any way.
In short a great problem solver for £60

[paulbuzz]

Just for fun, here's a frequency response measurement of the Behringer Ultra-G cab sim alongside that of the Mooer:

[attachment=151921:Ultra-G vs Mooer.png]

The Mooer cabsim is the purple line, and the Behringer cabsim the green line.
In some respects they are similar, but in other ways very different:[list]
[*]Both have a similar steep cutoff of the high frequencies above 3 kHz.
[*]Within the useable frequency range the Behringer has less bass, much less middle (a significant dip centred around 550 Hz), and more top.
[*]Like the Mooer, the Behringer also has a steep bass rolloff, but at a significantly higher frequency.
[/list]
This is borne out by how they sound subjectively. Neither sounds conclusively better or worse, just different. Each would sound better than the other in certain situations.

Apart from the sound, of course, there are various other aspects that might mean one of them suits a given situation better than the other:[list]
[*]The Behringer is about six times the size and weight of the Mooer.
[*]The Behringer doesn't carry the cabsim sound on its jack output. This may suit some folks better, as mentioned by the posters above.
[*]The Behringer is powered either by a 9V PP3 battery or by phantom power, whereas the Mooer is powered via a 9V DC socket. Again, take your pick!
[/list]

Edited January 9, 2014 by paulbuzz

[ahpook]

Very interesting. Thanks for posting the response graphs.

[Jack]

Would be an awfully nice box for those of us who wonder why there aren't many more cheap HPF. You get the thumpinator, the fdeck and ...... well what else? Thanks for posting the graphs

[Musky]

[quote name='Jack' timestamp='1389549425' post='2335409'] Would be an awfully nice box for those of us who wonder why there aren't many more cheap HPF. You get the thumpinator, the fdeck and ...... well what else? Thanks for posting the graphs [/quote]

As I understand it the roll offs on the graph above don't go anywhere near that found on the Thumpinator or Fdeck. The boost the Mooer gives in the lows might be some cause for concern with some cabs as well.

[0175westwood29]

ah just read through and saw it doesnt have a clean through!

dam!

[Prime_BASS]

On this, I have a cog effect coming in with a switchable "cab sim" on. I can choose for it to effect either jack output or XLR or both at the same time.
It has the same treble toll off as this, 3khz 20 of 24 db per octave pretty steep, mimics the treble response of my super compact, I actually got Barefaced to tell me what it should be.
Nothing else is cut, the lows and mids stay unchanged.

Designed primarily for the same reason westie is using it for. Sometimes I get made to use a cab with a tweeter and some times ( all the time) I am DI'd to the PA and so need it on the XLR too. So it solves the issue of having the line taking direct of out of my amp.