Line 6 FM4 Filter Modeler

There's a lot packed into this pedal, and dialling in sounds from the 1000s of possibilities using just five knobs (plus a wet/dry blend control) takes a lot of experimentation. It would have been nice to have more than 4 programmable presets; if you really enjoy playing with this thing you'll soon find you need to keep a notebook of your patches.

That said, hunting for good sounds is part of the fun with this box. Nobody needs more than four presets when playing live because most of these sounds are too extreme to use all the time.

You can get an expression pedal for this thing which, within a single effect type, will morph more or less smoothly between two settings (taking all 5 parameter controls into account). This is an essential accessory & increases the play value massively.

I haven't played this thing through a big rig, but at home it's one of my quietest stomp boxes. It also has true bypass, meaning that when it's turned off your signal doesn't go through its circuits.

The sounds fall into two categories: basic filtering effects that are variations on the wah-wah theme, and some analogue synth models. I don't use the filters much -- I've got a crybaby, thanks, and I don't need a "parked wah" or "auto wah"... I might revise that judgement next time I play some funk, though, as there are some nice Parliament-style sounds here.

IMHO the synths are where the real action is. I won't repeat the detailed descriptions others give below, except to say (a) yes, the tracking sometimes sucks, although playing cleanly with a compressor in front of the pedal with single coil neck pickup only minimises the number of times your notes turn int splatter, and (b) I like it when your notes turn into splatter anyway. There's a naturalness about the wya it glitches that means you can use these noises deliberately (playing double stops/chords will usually fire them).

One thing I noticed is that the synths seem designed specifically to take guitare input. I tried my electric violin and guitar with ebow and the tracking got dramatically worse.

It's true that what's a "usable sound" to me is probably not to you, and vice versa. But there are a lot of different sounds here and the quality seems to be uniformly high.

Have only had it for about 6 months, never gigged yet. It seems very phyically robust, but you never know, and given some comments below I would keep it well out of the way of moisture (I'd treat the equivalent battery of analogue gear that way too).

Never dealt with them. I'm in the UK, they're in the US, so my bet is that I'd have to get it repaired by a hacker with a soldering iron if it ever developed a fault.

If you like making whacky noises with your guitar, this thing is the best toy you can get for the money. Absolutely brilliant value -- imagine trying to buy even one quarter of the effects this thing emulates.

Yes, the original units do probably sound and behave a bit better, and you can chain them in bizarre ways, but it would cost you a huge amount more than the FM4 and be a lot of stuff to carry around. There's really no point in comparing this with the originals. Really it's a huge box of tricks at a very affordable price. I'd defy anyone except the most conservative folks not to find roo many really fun and useful settings to save on the four stomp switches.

Out of the box it's kinda ok, but beyond that it takes a lot of experimentation to get good sounds - it's actually much easier to make really hideous sounds than it is to make really musical sounds. This of course may be your bag. Most of the filters modelled have quite complex controls, so you need to really work with the manual and adjust things with care.

Hmmm ... I'm submitting this review because I'm about to sell mine. Ive had it for a couple of years and have persevered, but I'm just not a happy bunny. I think the problem is the same as with a lot of the other digital modelling products around - they suck tone and lack the warmth and shimmering quality of analogue. eg. I AB'd the Mutron model with an Electro Harmonix Q-Tron and the results were just plain scary - the Line 6 was harsh & cold sounding. If you want to get some funny noises for the hell of it, then there's loads here. But if you're looking for really musical sounds that truly enhance the tone of your guitar, I really think you'll struggle. Another eg. whilst I didn't AB it, I tried a Z-Vex Seek Wah a month or so ago and it was utterly sublime. The Seek Wah on the Line 6 simply isn't - it's like listening to an impressionist doing an impression of a famous person ... you recognise who it's meant to be, but you know it's not really them.

No problems at all.

Never had to deal with them.

I think I've just grown out of digital modelling. I've been playing for over 30 years and have done all sorts of stuff in that time. But at the end of the day, it's stunning guitar tone that makes the difference between hair standing up on your neck and something that just doesn't quite cut it. And I just don't think this pedal will ever quite get that hair standing up ...

it's just a matter of twiddling knobs until you get something that you can use...i sort of am familliar with how filters/synths work but you don't really need to know much about it to use this.

cool...i like how the speed can be touch sensitive on some of the filter patches and the mix knob is great for making a crazy sound more subtle if you want-the synths can be unpredictable(like the originals they are based on)but are definitely good for more than just strange noises . the spikes in volume can be a pain but you can kind of dial it out somewhat with the freq knob(depending on where other knobs are set!)-a compressor can also help with this like others have said. just the fact that all this stuff is in one box is pretty amazing.

i hope it's going to hold up-it has a year warranty so we'll see...i have not heard good things about line 6 pedals but mostly it's the DL4 that seems to break more than this one or the MM4-the reviewers below haven't seemed to have had a problem with theirs yet so even though i am slightly concerned i'm got going to stress about it.

with a little imagination you could use this for something with most types of music-i guess if i was in a country band(whatever that is these days)i might not bust it out but...you have all these good to great sounding models and can very easily store 4 completely different sounds-how could anyone not think that was a good thing?

...if you think that this product will be intuitive like the Modulation- and Delay modelers that line 6 makes, you are sorely mistaken. while all the mods share a common speed/depth basis and all the delays share a basic time/repeats basis, and these models come with cute stickers to tell you what the Tweek and Tweez knobs do to set additional model-specific traits), there is a WIDE variety of completely unrelated and dissimilar stuff crammed into this box. The knobs are labeled Freq, q, Speed, and Mode, but these things change a lot, depending on model. More to the point; this thing comes with stickers to tell you what the knobs do for each model, but these stickers have 1- or 2-letter abbreviations, and there is a THIRD sticker that serves as a legend to tell you what these things do... having to consult a fucking KEY for a stompbox with no screen is hardly ease of use...
(alas...i am still thankful it doesn't have a screen...).
However, this purple monster is a freakbox, through and through. people who buy the mm-4 and the dl-3 with their consistent time/depth fucntions and modestly variant Tweek/Tweeze variations want something they can understand, and feel good about themselves by having so many variations on a theme.
people who want/buy the fm-4 want it becuse they desire to relate to something they don't understand....something they can't master...something that reminds them of themselves; confused on the inside, and unpredictably violent, yet undeniably sexy....

this thing is very hard to use... but given what this thing can do, using it makes me hard...

I'm not rating the sound quality high becuase it sounds pristine, but because it's sounds are so flexible. The modulations on the mm-4 can only go so fast and slow, and only sweep so far (...I really wish the ring mod could be set for Deeper AM/FM...), and the delays on the dl-3 can only change so much (...but, then again, nobody needs more than two seconds...what the fuck is 23-seconds of GIGA-delay company BOSS thinking?...). of course these behaviors are limited in the name of emulating the classics they model.
thankfully, the fm-4 isn't really trying to caputure any classics, and is basically making it's own rules; hence, the filters and synths that it models offer HUGE speed- and sweep- ranges. Again, unlike it's brothers, the FM-4 is all about creating your own sound.

this huge range of parameter gauging is important for me, because I'm using it for a lot of stuff OTHER THAN guitar (microphones, drum machines, loops, keyboards), which have different dynamic and transient ranges...
thankfully, the frequency response range on all line six products goes a litte farther than guitar range - (but lacking low frequency heft makes it crap out on bass or kick drums... oh well, it still does a great job munging the sound).

For specific effects;
there are filters of all shapes and sizes, (and most can be adjusted in low/band/hi pass range...amazing...).
youv'e got everything from wonderful mutron 3 envelope followers to stepping filters (obi- and seeker), to crazy LFO stuff...

rather than review specific effects, I'll explain this;
if you don't know how filters work and how these things can be designed, then you are just likely to plug you guitar in, dial up a patch, and make some simple "mmm...that makes my tone kinda sweep/warble/sparkle" in a way that you'll either think is cool or stupid.
some of the effects are kinda weak, but still very well designed.
if you do know how filters really work, and (likely) have your own ambitions of how you wanna use them to shape sounds, then reading the manuals is like reading a porno-fantasy letter written about you... if you understand how these models work and how they can sound, then there is a lot of exciting promise in this very powerful and highly versatile package of filters.
to put it another way, only people who really know what filters are about use the Sherman filter bank, and I've actually heard that someone sold their sherman to buy two of these.

given all the promise of what the synths can do, thankfully, most of them deliver. the voice/formant stuff is a little dilute/weak and the comet trails is not what it's cracked up to be (...but still turns legato riffs into dripp-down-your-leg creaminess...).
overall, the filters whup ass
THEN we come to the synths.
the octisynth will inspire some people to start skronk bands, and just piss the rest of you tone-purists of...as far as I can tell, it's two effects that create two sounds out of your one guitar sound...on one end, your guitar seems to go through a ring mod and a LFO filter that's sweeping at audio FM-sideband ranges, making splatter noises, and the other end is a VCO (where your guitar controls the center pitch of a tone that you can set to stay constant or LFO warble at sickening sweep width and speed...). hence, as they claim, some VCO and vibrato and ring mod are involved...exactly how I don't know... the octisynth can be set to make snarling splatter noises or warbling tone wags, and some stuff in betweeen... either way, it turns anything into noise-fodder. my guitar player says "it's too fucking easy to play [in our noise band with it]," and he now hates me for getting him addicted to it.

the other synth models are more like guitar synths, in that they actually try to track the pitch of the note your guitar plays and recreate that pitch with a selectable waveform. different synth models have different waveforms (the synth-o-matic having the best stuff; the clickly pulse-mods and hummin

I bough it used, and the previous owner seems to have not treated this thing well. all the knobs and buttons and brain work fine, but the knobs are really dirty and get stuck.

I made the unfortunate mistake of getting a piece of snow in the knob-trough... it didn't work for 2 days, and I almost went comatose from guilt and remorse. after taking it apart (no warrantee to void) and gently blow drying it, still nothing... then, two hours later I tried again, and it sputtered to life.
these things are rugged as all hell in construction, as I have damn near used the heavy chassis to abuse my housemates...but the things have an achilles heel to moisture (read the beers story below)....the recessed trough begs to collect sweat and water and grease, vulnerable circuitry is obviously close to these access holes, and the knobs cannot be easily removed for service/cleaning. this is the one weakness.
I will definitely learn from my mistake, and I was lucky enough not to lose it. I cried a lot when I feared it was broken, but I made sure not to cry into it's vulnerable drip-holes.

it is definitely the dark-horse among line-6's stomp boxes, and among musicians.
most people will hate this, because it is of no use for it...
for a select few, this thing is WAY cooler than most stompboxes (including the dl-3)...



this thing is sickeningly powerful, and may be too versatile for some guitarists usage.
let me put it to you this way...
at practice, my guitarist was spazzing out on a synth noise patch. at some point, he dropped his pick and started using a COUCH CUSHION to rub the stings... I didn't hear the difference, and so I only fell over laughing once I notice the bass player fell over laughing and decided to look and see for myself.

...does this help me create music... NO... it is so powerful it makes me feel insecure about the frai and limited nature of my human feelings.
this thing has brought new colors (other than purple) and meaning into my life...it has even helped me maintain and reconcile my relationship with my girlfriend while she has estranged herself to california.
...no I'm serious...this pedal saved my love-life. thank you LINE 6.

It's pretty straight forward and the manual explains the functions well, but it takes a bit of tweaking, and there are lots of sounds to wade through before you find what works. Once you get a patch you like you can save it (up to four patches) and recall it.

Sound quality is a mixed bag: the non-synth filters are good for digital emulations, but the synths are not so hot. The Mutrons, Seeker, and Obi-Wah patches work well and are pretty flexible, these are fun. The Voice Box and V-Tron are weak and not of much use (they come off as weak auto filters...maybe with an expression pedal they are better). The Throbber, Spin Cycle, and Comet Trails are good for tremolo, vibrato, and chorus modulation effects, these are good and unique sounding effects and they are very teakable and versatile, and I think these and the Mutrons are the things that this box does well.
The synths are a bit of a disappointment, and they don't fair as well as the non-synth patches. The synths all seem to have a hard, cold, and dirty quality to them. They are not as warm and musical as an Electro-Harmonix Micro Synth, or as a Microkorg synth which also uses digital technology to model an analog synth. The synths will do a nasty distorted hard funk in-your face growl easily, and it is possible to coax a few nice sounds out of them. For example, there are some nice ring modulated metalic gong sounds, some cheesey organ sounds, and some queezy woodwinds and reeds, but overall the range of sounds is not as great as one would expect given all of the synths that this box boasts. I think the limitations come from there being a lack of control over the sound wave, as what this offers are preset patches that you can control tonally, but there is not really anything like sound synthesis going on, and the patches are all hard and "retro" sounding in a bad way. I also find the tracking to be weak, and this is with articlate single notes with the neck pickup, both single coils and humbuckers. Along with the weak tracking comes random dirt, farts, amd burps, but these have a digital glitchy quality which weakens the analog emulation experinece. To be fair, I've only had the pedal for a short time, but I've had time to suss it out to where I feel like I understand how to use it. Also, I've not tried it with a band. I have heard John Scofield recordings where I think he was using one of these and it sounded interesting, but not great (I think his tone is best with light effects).

Line 6 pedals seem pretty sturdy. I have a DL4 that I've been using for a while with out any problems. I've not had this pedal long enough to speak of it over the long haul, nor have a subjected it to any hard duty.

I sent them a few e-mails before and they got back with prompt and useful answers. Their help webpage is well designed.

I play a variety of funk, soul, jazz. I've been playing 20+ years, I used to work as an audio engineer, too. IMHO, I've got good ears for sound and tone. This pedal is good for auto-wahs and modulation effects, but the synths are not great....they are wacky and fun like a toy, but not as sound shaping tools. I think that this pedal would be lot better if they kept the non-synth effetcs (sans the Voice Box and V-Tron) and replaced the synth patch emulations with a decent virtual analog synth engine that would allow you to actually synthesize sound...they can do it on the $350 Microkorg synthesizer, so Line 6 should be able to pull it off. If the pedal had a synth engine that you could plug straight into with out MIDI, something akin to the Korg X-911, this would be an awesome pedal. But, as it is, the limited and cheesey synth patches that they put in the pedal take away from it overall. The stompbox design with four recallable patches is good. I bought this after having a DL4, which I really like, and was hoping for more. Given the size of the unit on a pedal board, and the price (in light of what's going on with synthesizer technology), I would not replace it or buy it again, unless I was looking specifically for a programmable pedal to do auto-wah and seek-wah, and some modulations (it's still cheaper than buying a Q-Tron and a Seek-Wah, but those will sound better).

I'm only giving a 6 because it's a trial getting used to this sucker. But that's because there are so many options available. If you don't use an expression pedal with this, you're missing out!

excellent sound quality. from the righteous to the insane. attack synth, obi-wah, seeker and comet trails are fantastic sounds! some are intentionally noisy, just like the original analog gear.... A VERY FUN PROCESSOR TO PLAY!!!!!

solid as a rock so far

never used them

a great toy, sounds good. the true bypass relays are a fantastic addition. some sounds are just too crazy too use, others are incredible!!!! not for everyone, but it works for me. from wah sounds, to phaser swells, to abrasive synth noise!!!!

let's see.. this is one of those pedals that takes a fair amount of ' tweaking ' on your part to find the sound you want for your particular type of music. 4 preset / save type function on it. i didn't find the manual all that helpful, although if you've used some similar type pedals before you know how to dial in what you want somewhat easily.

the sounds are, well, how can i say this? off the wall for some of them, damn good for some of em(again, this is all a matter of what style of music you play and what you are looking for in a pedal. it has a nice bypass on it, no problems there. keep in mind if you haven't used something like this that single notes are essential for the most part.

it's housed very well, seems like it could be thrown into the street and would survive!

i play metal, i'm still working w/ some settings on this pedal.. my idea was to use some of the functions for some sort of dark/ odd intros for songs, and it fits the bill for that. if you're into radiohead, there's some sounds for you with this. i was able to easily reproduce some of the sounds from the latest mars volta cd with ease with this pedal. i'm sure it's likewise useful for those into synth/ gothic/ industrial music as well. again, keep in mind that you'll need to work the pedal to get what sounds good for you. ( although i can see some impatient people tossing it five minutes after they get it because of impatientence and lack of familiarity w/ amps, effects, and even their own guitars.) overall, i think this pedal offers some unique sounds that can be suitable for many styles of music. i think that it's an effect that if used sparingly ( like many other pedals) you can really create something that sets your songs/ playing apart.

Ease of use is not a caveat of this model. It takes hours to really get the sounds you might want to use and incorporate into songs. The fact that you can save 4 presets is really an added plus though. Without this feature, the pedal would be a mess to use. The Manual is very comprehensive and useful, but finding one's own sounds takes time beyond this.

I see no problem with the sound quality of this unit, as others have noted. The original effects were not completely clean, and this is a modeler, not an "improver." I used this with a Hiwatt Dr103 (a very clean amp) and it performed very well. I don't understand why people comment on the usefulness of the sounds in this section. The usefulness is irrelevant, it is the sound quality we are rating in this area of the review.

I had no problems.

I bought this on ebay. To tell you the truth, I also sold it on ebay. It is a very interesting unit, but my band just didnt have time for me sitting around f$&*#ng with all the presets all the time. I like simpler effects that I can combine with my basic sound and then create a weirdness on my own. With the FM-4, the weirdness is there. Not much room for the creativity of the player, unless you are using this for background noise or more ambient uses. If I were to own this unit again, it would be used very sparingly, as I typically find a bit too obtrusive for typical use (except maybe for freak-outs). I probably just need more time with it (such as months). By itself, for it's purpose, it is an excellent unit. Whether it is useful is up to you.

Very simple to use, straight forward design. Easy to control numerous parameters with the twist of a knob or two. Save tones to the four stomp-box style channels by pressing the channel you want it to be saved as (A/B/C/D) and holding down for 2-3 seconds- simple. Manual is nice if you like manufacturer's reading material but you won't really need it to use this pedal properly.

The sounds this pedal can produce are some of the most vivid soundscapes that I have personally ever heard. However, I found the FM-4 to be just a little "too much" to effectively blend in with the majority of my guitar tones. If you just like to sit around, tweaking buttons and enjoying mind-bending sound effects than you'll dig it. If you want a mild filter-type effect to blend in with your live guitar tone than you might want to look elswhere. This thing sounds extreme in many ways but it's pretty hard to tame it for everyday use. Sound Quality-10 Sound Versatility/Usability 6

Feels like an M1. Sturdy as hell, well made. I would count on it for sure without a backup. I trust Line 6 products.

Never needed to bust their chops. Every single thing I've purchased from them has worked flawlessly, no exceptions!

Tremendous at what it does, which is royally f'ing your original tone and replacing it with some twisted frequencies from beyond. I dig this pedal, but only so much. I just cant use it as much as I originally hoped because it is just so drastic an effect. A little filtering seems to go a long way. I'm just glad I didn't pay for it new. Used it's a steal.

My only complaint with ease of use is the fact that once you've saved a patch, you have to know what they were, because you will never get them back again. It can be hard to get your settings back, especially on this one. Some of the effects can get so tweaked out (I love that by the way) that I've had trouble finding them again when I want.
Line 6 should think about making new versions that instantly recall the settings, sorta like those Fender modeling amps where the dials move to where the presets are supposed to be.

I really love this pedal. It's easily the most used pedal that I own (I own a lot, even though I rarily use most (I'm what you might call an effects junkie)). This pedal sounds great if what you are looking for are real unusual sonic textures.
Not to say that you can't have tone with this pedal though. There are plenty of settings that allow you to hear the guitar beyond the effect very clearly and precisely, it's just that I enjoy making noise with this pedal rather than making chords and what not (by the way, chords don't come out real good with most of these effects, as it says in the manual).
This pedal isn't noisy, nor is there a volume drop.
I play a mexican tele into this, a Korg AX1000, and a line 6 delay modeler into a vox AC30. With these things, I can make all the noise I want. It's relatively simple for my band, Didley Squat. I rely on making noise as well as actual guitar lines, so there you go.

I've owned this unit for a year and a half, and I've been gigging with it for a year. For some reason, I've only been through one set of batteries, which is real odd because I remember my delay modeler eating up batteries much faster. But, with a power supply, this thing is stupid-reliable. It's never died on me. I've come to rely on this thing heavily, especially because I use this pedal for so many of my band's better songs.
I've never had a problem with it in any way!

Never dealt with them, don't plan to.

This pedal is truly good for any style of music. Although it fits perfectly in my band, whose style can only be compared to a mix between Mindless Self Indulgence/They Might Be Giants/other weird funky stuff, I've actually been able to use cool settings for my own music, which is far more mellow (influenced by the likes of Radiohead and what not).
I love this pedal so much, and if it were to go missing, i'd be really depressed, because I'd have to find those goddamn settings all over again. I have no idea how I even came upon them, so, I'm sorta screwed huh?
In any event, this pedal is awesome. Buy it if you're feeling adventurous.