I'm going to offer different advice than what you've already heard.
First off...where am I? Wow this place looks so different now! LOL!
 
Ok, I'm going against the grain here but this is my belief. Never cut anything "for the sake of." After listening to your track, it appears to me that you can't hear what is going on in your song to make the right calls.
 
If your monitors are not tuned you're wasting time. If they ARE tuned and that's what you've come up with, you need to be taught how and what to listen for. I say this over and over in just about every post when someone is having problems with a mix.....you can't do this stuff and expect results if you don't have your monitors eq'd for flat at the least. Some people say it's room tuning....I say give me a set of monitors that are tuned correctly and putting out flat results and I'll give you an acceptable mix every time.
 
Your issues in MY opinion are a misrepresentation of what you are actually hearing. I can hear it in your mix, mun. You have good stuff all the time when you have shared your material. I always enjoy your songs. But your mixes are lacking because you can't hear things properly so you don't know what to fix. For example, there is 0 kick drum in this mix you posted. I can't hear any kick consistently. If YOU are hearing consistent kick or enough kick on your end, your monitors are putting out too much bass....or you have a sub that is so hot, it's messing up your decision making.
 
This in turn is forcing you to mix bass light and is also clouding your vision. OR...because of all your cuts like you said....it damaged the mix. But if that's the case....you have nothing going on under the freq's you have cut. Where are the good lows other than the bass? Totally gone in this which has totally made the mix small and thin. Your bass guitar has no definition and has 2 tones...a simulated sub low harmonic tone and the actual tone. The song that follows this has the same issue. You don't have any good low end to thicken things up. The kick drum could just be turned up...but if it had the right low end pushing it, it would come right through. But you have all the good low end taken out...which should not be happening considering you mentioned cutting 150-500. I'm not hearing anything under 90-100 Hz (give or take) other than whatever over-tone that bass is showing us.
 
I read from guys every day that say "yeah, dial 330 Hz down to clean up mud." What if your sound/mix is not loaded with 330 Hz? You don't just start cutting stuff unless you can actually hear these frequencies clouding up your mix. In order to determine what frequencies need work, you have to be able to hear them. Mixing should NEVER be a guessing game. You hear it, you fix it if need be, you move on. All this stuff taking a week to mix one song, or a month or whatever people take is due to them not hearing things properly or not knowing what to listen for.
 
At the end of the day, if you're using the "by the book" method more than "by ear" that's a huge issue that you need to break out of brother. I could be completely wrong in what I'm saying here...but if I had one shot to say what was wrong here, the above would be my take. Good luck, hope some of this helps.
 
-Danny

Quite right!  Where am I???  LOL!!!
 
Thank you for those thoughts.  That may start to shed some massive light on my issues?  Let me go back to the mix and listen again to see if the kick is as prominent as I thought it was.

Yeah man, in my completely un-treated room, the low end is ALL over the place. As Danny said, no kick at all. I've got nothing. Bass is popping in and out lots but I'm pretty sure there is a modal ring in my room right on one of those notes, so that's partially a problem, but I know my room a little, and the modal rings are not as extreme as I'm hearing from this mix. My room response is about 10dB variation around that mode (sounds like 140Hz ish). This mix sounds like the response I'd hear in a typical room with 20dB variation - it a really small room with brick walls. I'm in a medium room with wood walls (resonance isn't as bad in wood as lots of the energy escapes and doesn't bounce back in as it does with brick). So I'm thinking it sounds like you've boosted something in the bass poorly which is making it sound off, or your recording is off. Did you DI or mic the bass?
 
Please keep in mind I'd don't know my room too well yet and it's not treated well at all. I've run a few response tests though so I've got an idea of it and from working in other rooms where I've also done tests.
 
Have you checked this mix on a decent set of headphones? I'f you've got a null in your room right where I'm hearing this boost, you may have boosted it to compensate to hear it. And if you have a mode right on your kick drum fundamental.. well..
 
As for the 300Hz is area - you've cut too much out for sure. But the kick and bass are bigger issues right now. You need to fix those. Once you've got that, I'd think let the guitar probably fill out that area, and maybe a little bass too, depending on which suits it best.

Danny's assessment of the mix is spot on. He has a  way of speaking about the mix that gets right to the heart of the issue.
 
I mix in an untreated room. However, I have learned, to one degree or another, the speakers I mix on. I also have ARC which is a tool I use (not always) when I mix. It helps to give me a more accurate picture of the actual mix.
 
I also check the mix on both my headphones (in the studio) as well as exporting it to my mp3 player where I am used to the sound quality of professional mixes on that player. Very often it's there, where I catch the flaws, bass freqs too heavy or too light, high end crispy or mushed......
 
I never make assumptions that any given freq should be cut or boosted until I hear the song playing back in the mixing process. I say that, but I do generally have a steep drop (EQ) for everything below 40hz as a starting point. It's in the preset I use with Ozone. Nothing, however, is cast in stone. Each mix requires totally different tweezes to the preset to get it right. I seek to have the mix sound full, not boxy, thumping and full on the bottom without mud, and crisp on the high end without frying the tweeters in the speakers.  Most often, the EQ curve resembles a mountain with a wide flat top, and sides that are fairly steep on the left and not so steep on the right (hi end) and the flat top area is pretty much just that.... flat perhaps with a slight curve so there is full range stuff happening there. But that's just on the master.  EQ in the tracks is also customized to the instrument and the total mix. Again, what worked in the last song doesn't always work in this one.
 
Ditto to what Danny said at the end.... forget mixing by the book or by the numbers, and learn to mix by the ears. Learn what you need to listen for and it opens a whole new aspect to mixing.
 
I almost always start my mixing sessions just like the old gigging days when I was setting up a sound check for my band in a club. We always started with the drums and the bass. One then the other..... get them sounding good by themselves and then together..... then start adding the other things in the mix, one by one.  I like to put the drums and bass into a bus so that once I get them where I want them I can easily change levels slightly and keep the ratio between them constant.
 
Use the song forum as well as this one as a sounding board for the mixes and use the advice. This has been one of the main ways I have learned things. (at least to the point I am now.... with still more to learn) Post the tunes and ask about the mix. People will help you dial them in. As a result, your craft gets better.
 

Wow guys!  Glad I posted this.  Learning a lot.
 
Want to describe my set up and hence predicament.  My studio has been relegated to my post divorce bedroom.  It is cramped and a perfect square.  The monitors are flush against the wall.  No sub.  I have some Auralex foam on the walls and ceiling.  But I have learnt that stuff does not do much.  So yes it is highly likely that I have an issue with my mixing environment.  I should say that I use IK Arc.  It helps a lot.  However it is clearly not a panacea.
 
In the near term, this is what I have to live with.  No space for bass traps or proper monitor placement.
 
So my question is, would I be better off with a pair of cans made for mixing?  The headphones I have are terrible and not made for this stuff.  If so any recos?

ahh, the old 'post divorce-this is what I have left' situation.. 
 
You mentioned you didn't think the auralex was doing much.
What is your placement? I've got my walls treated with it and it seems like it works very well.
As for cans, I recently purchased AKG 701's. Very nice.
I have not mixed extensively with them, but when I do use them they reproduce very well, in
my opinion.
 

One of my little rooms is 12x12 so I can relate. On the ARC thing....how accurate were you on it? If you didn't set it up like I did in this document, do the ARC procedure again.
https://www.dropbox.com/s/pd22yue8jzbroo1/DannyDanziARC.pdf
 
Me personally, I always like a sub. Nearfield monitors to me just don't give me the low end I need and I'm always second guessing. There are many people that are against subs in a small room. I am NOT one of them. You can always control the amount of sub you have going on. If you mix bass light you are using too much sub, so you back it down a bit until your mixes start to sound like they have enough bass. If you mix bass heavy, you raise the sub a bit so it makes you mix bass lighter.
 
Without the sub, you have neither and it's like peeing in the wind as far as I'm concerned and you're always gonna get wet. :) So if you can afford a sub, I'd definitely look into one and look into re-ARC'ing your room if you didn't do it the way I've explained it. If you missed one of those steps or didn't do something quite right, it can make a world of difference, honest when I tell you. 
 
I find it strange that ARC is adding that much bass to your mixing realm to where when WE hear your mix, there are no sub lows in it. Something isn't right somehwere. Granted, room correction, Auralex etc is all good stuff, but we gotta get your monitors to be putting out the right information first. I've mixed in some of the worst rooms you can imagine. The rooms didn't kill me as much as not having corrected monitors did. ARC has always bailed me out in those situations without failure unless I'm using the old NS-10's without a sub.
 
Also, if you can get those monitors away from the wall just a little bit, it will help you. The problem with "against the wall" is the extra vibration going through the wall...rattles, artifacts...you just don't want that if you can help it. I know sometimes it's hard based on your space...but even if you can get them to the point of not touching...it will help some.
 
As for headphones, you'll get mixed opinions here. I'd like to see you get your monitor situation sorted out as it will always be the better way to mix. I have AKG K-240 DF's here as my favorite headphone. They are discontinued but have another out that replaced them. I've heard the replacements are just as good or better. But those cans work incredibly well and I've always done really well with them. However, nothing compares to when I use my monitors. I get good mixes in cans...but REALLY good mixes that make me smile when I use my monitors. Good luck!
 
-Danny

Danny DanziMe personally, I always like a sub. Nearfield monitors to me just don't give me the low end I need and I'm always second guessing. There are many people that are against subs in a small room. I am NOT one of them. You can always control the amount of sub you have going on. If you mix bass light you are using too much sub, so you back it down a bit until your mixes start to sound like they have enough bass. If you mix bass heavy, you raise the sub a bit so it makes you mix bass lighter.
 
Without the sub, you have neither and it's like peeing in the wind as far as I'm concerned and you're always gonna get wet. :) So if you can afford a sub, I'd definitely look into one...

Completely agree! I've learned this the hard way over years of practice. I don't use the sub to make the mix sound good, I use it as an alarm. When it starts making too much noise and I start to notice the SUB, I know I've got my bass out of whack. Once I think I'm getting close, I turn up the monitors and sub and go into the next room to see if anything sounds really bad...lol.
 
Doing it this way allowed me to spend on really good monitors, but save on the sub. Also, you really do need to get your monitors off the walls.
 
Regards,
Dan
 

There are some other major issues with your music Sunny that are actually pretty important and much more important than any mix or room issues. And firstly please I am not being hard on you here only truthful. This advice is important because it is this sort of stuff that effects the final mix in a very extreme way.
 
The two things that really grabbed me about the song, the first was the groove or timing is not great. It is pushing and pulling all over the place and sounds uncomfortable to me. This comes first before anything. Once all the notes are in place timing wise everything from that moment on will seem easier and better.
 
Second is arrangement of parts stuff. The music is not very well organised and there are a lot of parts just playing over the top of each other and overlapping and it sounds a bit disorganised and a mish mash to me a bit. Too many things going on. Over complex. The music needs to be edited in such a way that the essence of the groove remains and your arrangement because it is good in fact you just need to clear things up to spell it out more so and with much more space around the parts and less going on.
 
Those drums of course need sorting out, once drums are in the music you need to hear them and properly and all parts of the kit equally. 
 
Danny got me thinking too about a mix may have no excess energy in the lower mids at all and the reason is that if the parts are well organised and don't overlap and interweave much more so then there will never be too many things playing at the same time. Hence much less build up of lower mid energy is possible. This is the sort of stuff that is not talked about much but contributes to a poor mix in a big way. The best productions have things weaving in and out of each other, not overlapping at all or for long. Space around the parts. You have got to hear the black backdrop in your mix. It is the music that makes it happen, not your engineering or production.
 

Great advice.  Thank you!  I will have a listen tonight.