Thought it was worth keeping this topic going because, as I am learning, it’s a tricky subject but critical to our listening enjoyment.
I have a resonance/pressure build up in my room which comes in on tracks with very low bass - think Erykah Bada Rimshot for instance. I’ve tried other speakers here, positioning, etc. The only thing that fixes it is using DSP in Roon, but this of course means using vinyl is difficult on these kind of recordings.
Thinking of how to move forward and having read this thread, I thought bass traps would not really work or pass the interior decor committee so I borrowed some PSI AAVAs. Expensive but if they did the trick… They had zero effect in my room, nothing, so much so I had to check they were switched on properly, I know others have had great success with these so I was kind of disappointed.
I’ve just tried the filters from Home Audio Fidelity, thinking that if it has to be DSP then get the best I can, again following reviews on here. In my room I could hear no difference from the filters I had already developed using REW so, no joy there?
So, my thoughts turn to bass traps and the like again. I have large French Doors one side of my room so as an experiment, I just opened those wide, and also the window opposite the speaker to see what would happen, kind of a surrogate bass trap/release. Same resonance, no difference.
All of this leaves me a bit confused but I’m left with one last thought centred on my suspended timber floor. If it’s not connected to this then I’m out of ideas.
Which frequencies are you addressing via DSP (?), as the 606’s don’t go as low as some 'speakers. Reads like you’ve a room node kicking off – I’ve got a doorway with a piece of glass which vibrates at certain frequencies.
Can you provide a diagram/pic of the space and kit locations etc,?
606s go down to 30Hz, my issue is around 38Hz
This is pretty much what I get
The room….
Speakers tweeter to tweeter - 2.2M
Speakers to Listening Position - 3.2M
Im really no expert in this, but I have the same power amp and speakers as you. Bass on the 606s has been a little tricky in the past. The thing that really tightened up the bass and stopped/reduced resonance on some songs were powerlines and a good power pack. As someone else pointed out, you just needed to get more/better AC to the system? Perhaps cleaner power helps the isobaric nature of these speakers? You could try borrowing some stuff?
My suspicion is the 'speakers (in an ideal world), need to come forward a fair bit (up to ~0.45x the width of the room if the Cardas model guidance is believed).
Siting 'speakers back near rear walls generally increases bass reinforcement, but this isn’t always a good thing.
Have you moved them fore and aft?
I have yes, quite a bit forward with no difference. The Titans are supposed to be fairly easy to sight and happy close to the wall. I borrowed some DeVore Babys recently and had them well forward, I still had the same effect.
Interesting thought - I was going to investigate a power improvement as I do get humming in both my power amp and my 222.
In which case, I think the best thing would be to plug the dimensions et al in to one of the models out there (e.g. I think GIK have one), and see what it throws out. I suspect you may benefit from some room treatment, assuming it is tenable to go down this path (?).
My room is similar sized with patio doors and window. I changed from Isobariks to 707’s and it highlighted a definite room problem in the mid 30’s HZ. I went through GIK and now have a corner soffit trap as well as 2 x bass trap/diffusers on the wall at the far end from my speakers plus a couple of home made traps in the corners behing the speakers. It has made a big difference in my room. Instead of using the speakers out in the middle of the room I now have them c 30cm from the wall
Treating first reflection and second reflection points on the walls, first reflection points on the ceiling, corners and behind listening position improved my issues…. Have a chat with the gents at GIK they are helpful and they have some nice oak fronted panels now.
I found it to be the some of the parts with panels, I had to go “all in” to get the benefit. I just have the ceiling ones to put up.
I also found room construction played a big part, in my old house with solid walls everything sounded good but plasterboard in my new house not so good!
That is quite a bump in the low frequency!
Thoughts…
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move the sofa away from the rear wall and treat the rear wall with monster bass traps from Gik
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if the chairs are as close to the speakers as they look move them, maybe to 1st reflection point
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you mentioned suspended floor. What is below it? Mine has a 5 foot space/foundation below and acted as a giant uncontrolled sub woofer. Isolation (isoacoustics/stillpoints etc) under the speakers made a huge difference. My hunch is this is the issue if you have not isolated the speakers.
I don’t know the Kudos Titan and can’t judge whether they are actually optimised for placement close to the wall. I have GIK Aukustik Room threatment myself. The best thing to do is to send the floor plan directly to GIK. They are very helpful and will advise you free of charge. The standard solution is to treat the corners and frist reflection points in the room. I have followed this and have achieved a massive reduction in reverberation time and a massive improvement in sound quality, more than by changing individual components.
There are various approaches for the listening position and speaker placement. Usually speakers need “air” around them. In addition, the listening position should not be directly against the rear wall. Is it possible to place the sofa further into the room? The ideal starting point would be the equilateral triangle, i.e. the same distance between the speakers (tweeters) as to the listening position. Other approaches suggest that the distance of the speakers from the rear wall, as well as the listening position from the rear wall, should be 1/5 of the room length. You can vary from there. With a bass-heavy piece of music, the speakers can then be moved 10 cm forwards and backwards.
There are also numerous instructions on the net for positioning speakers. I found these helpful, for example (Click here).
The bass performance depends not least on the power supply (as mentioned above) and the components used. When I added an NDac (to Nait50 - ND5XS2), the bass range and fundamental became much stronger. I compensated for this by repositioning the speakers in the room. It takes some time, but it’s worth it.
I’m no expert but did have a very similar frequency curve and “sub bass issue” which I believe relates to a standing wave based on room size.
To try and resolve the 38 hz spike I tried:
- Speaker placement – some impact but domestic harmony intervened.
- Listening position - big impact but domestic harmony intervened.
- Gaia’s for speakers – no impact on 38 hz spike but did improve clarity higher up frequency range.
- Passive room treatments – no impact on 38Hz spike but helped pull up some frequency troughs from 60-200hz. Gave me more not less bass.
At this point I just assumed I’d bought the wrong size speakers for my room.
I then tried a convolution filter using REW and then adding it in Roon, that works in the same way having two subs does, cancelling out peak responses in a room. For me this worked very well blue line original frequency response, purplish line after:
Given you’ve got REW easy to try. Clearly only works in digital domain. Co-incidentally I was speaking to Luca from GIK Acoustics about this and he agreed the cheapest/best solution for a sub bass issues is DSP. As with everything I think this is very effective but YMMV.
What were the DSP filters you tried? From the plot you posted it looks like a couple of parametric EQ points could be a lot of help (~ 38Hz and 68Hz, you’ll have to experiment with Q)
Thanks all for the replies, all interesting and useful input. I was on the track towards GIK but this is what led me to trying this afternoon with the French Doors open and the windows, my logic being that this should let the low frequencies out 
I read on here somewhere that a large bass trap was like a hole in the wall so that was my thinking.
@Ryder35 I’m afraid moving the furniture around doesn’t really work, we use it as living room so I’m somewhat restricted in what I can do and that also means I’ll have to go careful with panels etc. The chairs by the speakers, I’ve tried them away many times, if anything they are slightly better where they are (marginal) no improvement moving them away.
The floor, I think there is at least 3 foot underneath and the floor is quite bouncy in places, so yes, I now strongly wonder whether this is the problem and Gaias/Stack Auva are on the next up list of things to try. I did initially use the spikes but I found some improvement locating them on a granite cutting board with spikes in shoes.
@Tapp @mbear I use the dsp that was calculated in Rew based on the readings I show above. It definitely works and very well, it just means I’m restricted to digital source. That may end up being the final answer but I want to at least see if I can resolve the root cause. If not then streaming it is.
To be clear DSP describes both Parametric EQ (a bit meh) and a convolution filter (wow). In my experience there is a very big difference between the both in terms of sound quality.
I’m using convolution following my REW measurements. I tried low shelf eq when I first encountered the problem but, I agree, the convolution filter is much better.
What is the floor construction, can the speakers be moving it? Those Townshend things or similar might put the idea to the test.