Acoustics

As dweller suggests move your speakers about - the spikes you are experiencing suggest to me that they are the result of room nodes which can be changed by speaker relocation. Another possibility is to use a sub woofer crossed over at 120hz +/- and locate the sub in a different plane than the main speakers. I did this with some planers which were set up traditionally (triangulated) 5ft out into the room with a huge spike - put the sub against the wall between the speakers and ended up with an almost flat FR. (I'm not suggesting that that is a universal cure - but what is possible. A speaker manufacturer who posts here on occasion uses multiple subs to great effect. 

No sub. I've tried to change speaker positions over and over again. Therefore I bought a XTZ Room Analyzer and it is from those measurements I've got the figures.
I don't have room for multiple subs and I tried with one sub once, but it only got worse.

You might consider changing your listening position - too close to a wall for example can really boost the bass. Inches can make a difference. If you haven't already done so, you might check out the Cardas set up - it is at worst a good starting point for system set up.

Hey Simna,

What speakers are you using?

The usual path to do this well is start with bass traps. My current favorites are the GIK Acoustics soffit traps, and then add EQ.

The bass traps help dampen ringing in the room, which makes the EQ a lot more likely to work. Alone the bass traps won't be enough. If you have enough funds, and can do anything in the room, tuned helmholtz resonators would work too.

If you have the ability to bi-amp, or use a sub, that's kind of the best compromise. That way you can add an EQ in series with your bass and leave everything else alone.

Alternatively, Anthem is making VERY nice and affordable pre and integrated with room correction built in. Like I mentioned though, they work best in combination with room treatment.

Best,

E

@simna, your problem and question is a deep and complicated one. It cannot be answered in a short, concise way here. To get a complete understanding of the issues involved will require many hours of research and reading on the subject of small room acoustics.