bass boom
- Thread starter Neil P
- Start date
Neil P
pfm Member
So ... as my room is being emptied/moved around for decorating, I am tempted to try REW with different furniture configurations now. That gives me a baseline to test aganst with carpet in, additional furniture etc.
Am I right in thinking I run the software on a laptop which i connect to my stereo via headphone>RCA ? All i need to buy is the mic?
Am I right in thinking I run the software on a laptop which i connect to my stereo via headphone>RCA ? All i need to buy is the mic?
How can you move the entire room but not the speakers?
Neil P
pfm Member
After decorating, the sofas and stereo will be back in exactly the same positions as they are now (speakers could move a few inches at most). However, whilst the room is being decorated (and out of use by the family), i can have a play with rug in/out, book shelves in different positions. This is just out of curiosity to see what, if anything, makes a difference. It's just easier to experiment as the clutter will be removed (lego, books, small table, etc). It may be testing shows the optimal room config means putting furniture where furniture simply can't go in a real world situation, but at least satisfies my curiosity.
A few inches can make a big difference.
The sound is reflecting off the walls so if you move the speakers relative to the walls you change the paths of those reflections. When you get bass boom what is happening is that reflections are coming back and matching up with either other reflections or the direct sound from the driver so 'doubling' the strength of that wave. Even moving the speakers two inches can be enough to stop the waves matching up as well and reduce the problem.
Another thing most people forget about is that symmetry is a bad idea. If both speakers are exactly the same distance away from the rear and side walls they will both experience bass reinforcement on the same notes! Yet that exactly what most people do, they try to get the speakers symmetrical. My speakers are different distances away from the side walls, it's not obvious but they are. I do still get some doubling but it's not very noticeable or intrusive. It was pretty chronic initially.
Move the speakers as much as you can, try different angles and remember to use different recordings as some tracks have bass boom on them!
Chris81
pfm Member
But not in the bass: Wave length...you know
Yes it does. In theory it shouldn't but I've found that in practice a two-inch difference on speaker position is audible.
S-Man
StrivingON
I must be imagining the large differences in response below 250Hz shown in the room sim in REW, when moving the speakers a couple of inches back/fowards
Maybe the REW people have cheated physic?
awkwardbydesign
Officially Awesome
I did that trying to cure bass boom on one album. Then I went to see the artist and he had bass boom! Un-amplified kora, BTW.
But I guess you can misunderstand it?
Over the years I've had countless debates with people who've been certain of things because of theory rather than trusting their ears. All CD players sound the same, all amplifiers sound the same. I guess it's easier than admitting there might be something happening you don't understand.
Back in the day when a lot of us were using Linn Kans it was well understood and accepted that a few inches of difference in position against the wall could make the difference between some bass and no bass. It's a weird thing, bass, and by far the hardest and most expensive thing for a system to get right.
Neil P
pfm Member
Oh no.... Don't say that!
ToTo Man
the band not the dog
Having taken literally thousands of in-room measurements over the last 11 years I agree with @Chris81. The lower the frequency, the more you need to move the speaker and/or listening position to cause a meaningful change in frequency response. The notion of being able to ameliorate a 40Hz, 50Hz, 60Hz, etc, mode that causes room boom by moving the speaker or listening position as little as 2 inches is laughable. It may reduce it by a dB or two if you're lucky.
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If I were to put a microphone in front of my system I expect the resulting graph would be horrible. Do I care? No. I don't listen to graphs. It sounds great to me, everyone who hears it thinks it sounds great, why would I want to feck it up by trying to produce a nice graph?so ... what microphone choices are there? Anyone want to sell me one?
jobseeker
pfm Member
My understanding is that we can change the position in the room at which the mode occurs, rather than reduce the level by anything significant.
tuga
Legal Alien
Because the system will sound better?
A microphone is cheaper and more effective than most upgrades.
awkwardbydesign
Officially Awesome
My microphone doesn't play very loud, I can hardly hear it!
ToTo Man
the band not the dog
An in-room measurement is still informative even if you decide not to act upon it. For one thing it stops all of us going round in circles like headless chickens trying to propose solutions to the OP's room issue without knowing exactly what the issue is!
~
@Neil P, a UMIK-1 is the easiest plug&play measurement mic if you don't mind forking out around £130. YMMV but it's the best investment I ever made in my system.
darrenyeats
pfm Member
True if you consider a single low frequency in isolation. But the overall bass balance /can/ change a lot as you get two inches nearer to a wall - I'd say two inches when near the wall isn't the same as two inches far out - due to SBIR impacting all the frequencies across the bass (not necessarily a lot, or even in a predictable way, if you were to consider just a single low frequency, but subjectively and overall yes IME).
On the wider topic moving speakers and moving listening position aren't equivalent and interchangeable - best to experiment with changing both.
A listening position of at least 1 meter into the room is very beneficial, not just for bass but for everything.