low frequencies

Hey all, Running a pair of Thiel CS2.4 floor standing speakers and the bass is only sounding best when i'm not seated and in a rear corner of the room such as is where the equipment rack is. Is their a tradeoff in other areas of the sound quality to get more low frequency at the seated listening position?   



I am glad it worked out with a relatively simple fix. Room boundary interference is a frustrating one that can make great equipment sound bad. Moving the seat is 100% a practical solution that works if you have the space.

the 3.6’ (assuming driver face) technically makes a dip at 78hz. Closer to the wall will cancel higher and farther will cancel lower. I think thiel recommends a minimum of 3’ from the front wall which would make a dip at 94hz off the front (other boundaries matter too and can even it out or make it worse, really need to add all of them up and average them). Anyway 3’ works pretty well when not using subs. Less is actually better for the bass. I have found as close as 30” to be fine. As you get closer you lose some of the depth to the soundstage. Pushing them back just a bit might improve your bass a bit more as 80hz and down is critical for bass impact.

I typically use subs and in my main systems I pull the thiels 5’ off the front wall but crossed over at 60hz to sub which fixed the null the 5’ distance caused. Without subs I like to stay 39” or less from the front wall or more than 7.2’. 7.2’ into my room is pretty awesome but my kids run around the speakers and I can ’t deal with it lol.

Boundary calculator here if you want to see where the nulls are in your room.


James633 thanks for sharing those thoughts. You have a lot of experience which is always nice to hear about. I was able to get much better sounding bass from a seated listening position by putting the couch further away from the speakers. Now at 13 ft from the tweeters and 3 ft 6 in  wall behind me. I think it was a bass null where I was before. 

AM Acoustics room mode simulator is a great place to start. Look at the lowest modes and try to keep both your speakers and listening area out of them.

After that, it's good to measure to see exactly what your problem is. 

TY for the suggestions DILL, The distance is 10ft ear-tweeter distance. Funnily enough I have moved the couch back another 2 feet and bass is sounding much more full. Polarity is all good😎

the key is: those speakers, in that space, at that location


I suggest: Get thee a simple Sound Pressure Meter, tripod, set at ear height at listening position



next a test cd with individual tones. Note: I scanned several Stereophile Test CD’s, others, none of them have the full range of frequencies this test disc has (29).


you will know how flat of a frequency response your speakers are producing, IN That Space, AT that location.

Next, try new positioning and different toe-in, measure the differences.

Amazing Bytes is hard to find, and expensive, I can find a used copy if interested.

I have a pair of Thiel 2.4 in my second system. They were in my main system for a few years. I have owned them for a very long time and have had them in 4 rooms with at two different houses. The Thiels have great low bass extension and texture. Mean really good. But it is tuned flat so not boomy at all. Typical HI-Fi turned bass.  

this is 100% a room issue. Try pushing the speakers back so the driver face is 24” off the front wall. The sound stage will still be fine and the bass will be impressive. At that point if you can move your chair around until the bass sound good, sit there. 

That is a good size room and it looks like you have them on the short wall so placement looks good. How far is the listening position from the imaginary plane between to 2 speakers? I know this might sound silly, but double check to make sure both speakers are hooked up in proper phase.

mlsstl , I really appreciate the valuable information. As with everyone else's shared experience and advice. I've not moved the cabinets closer to the walls yet. I'll try this out! 

As far as placement. The speakers are 30 in. from both the rear and side walls and 7ft 1/2 feet spaced apart from each other. (straight ahead currently , no toe-in) Room dimensions are 12ft 1/2 wide 18ft length 8ft ceiling . Thick carpet, curtains and couch. 

Try putting the speakers about 3 feet from the back wall and about 8 feet apart with the listening position about 8 feet from the center of the 2 speakers. What size is the room?

I must have been lucky when setting up my system the way that I did. I chose the long wall to be my front wall as there are no windows behind it and I ended up about  8.5' from the front plane of the speakers which are 30" from the front wall (measured from front plane of baffle) with my head less than 1' from the back wall and I get all the bass I need, and then some.

I also found out that not all speakers had great bass. My last two choices were/are great concerning bass response. My old JBL 4319 monitors literally could shake and over load the room and my Atalante 3 monitors have almost the same effect.

Two speakers that I had from Decware were quite weak with the bass and the Tonian Labs speakers were okay as they revealed so much info that my mind could fill in the rest. I concur that moving them around (as much as a PITA that can be) could result in some happy and satisfying results.

All the best,

Bass quality is dramatically impacted by the shape and size of the listening room along with the placement of the speakers in the room. That's because bass notes have a long wavelength -- the 42 Hz low bass note on a bass guitar is about 27' long.  That's why sometimes one bass note will sound much louder than another. Square or cubical rooms tend to be worse on this point than rooms where the three dimensions (width, length & height) are all different. 

For no cost, you can try moving the speakers around to different positions and see if you can get a bass quality more to your liking. Moving the speakers closer to the wall behind them will increase bass, as will moving them into corners. However, this may exacerbate room node problems.

You can also experiment with room treatment and bass traps to help even out the bass and reduce the room node effect. 

The tradeoff is that a speaker position that helps improve bass quality may hurt the midrange or highs, or adversely impact stereo imaging or the soundstage.  it can take a lot of experimentation to find out what works best for you, keeping in mind that this sometime gets kickback from your partner who may be more interested in interior design than sound quality. Some people even go so far as to bring in an acoustics professional to help with improve things. 

The nice thing about a lot of the placement experimentation is that it's free. 

Yes, place both speakers against the wall. This offers the best and most even bass. It is called the Allison effect.