 Re: SPL and dBs, what can I hear?
|
Joined: Jan 2007
Posts: 10,490 Likes: 116
shareholder in the making
|
shareholder in the making
Joined: Jan 2007
Posts: 10,490 Likes: 116 |
Quote:
for instance, the M3 shows ~74dB output at 40hz (compared to 84-88dB for frequencies higher than 100hz). can i still hear the 40hz or does this much of a drop pretty much make it impossible to hear?
Well, that depends. The M3's 74dBC output at 40Hz is measured from 3 feet away with a 1 watt input. At half a watt you'll get 71dB and at a quarter watt you'll get 68dB...at 3 feet! If you are sitting 8 feet away and you are listening to two of them, you may get ~65dB. To know whether this is adequate, you need to know what your ambient SPL is in your room and also how well you hear. If you are younger and have not abused your ears, you should easily be able to hear 40dB at 65dBC.
You should strive to have your music at least 10dB higher than ambient. If you are in an apartment located on the street, you may have an ambient noise level of 70dB so 65dB is no good. My basement which is well isolated still has an ambient noise level of 55 to 60dB (because of the compressor noise from my noisy fridge in the kitchen right up the stairs).
I hope this helps.
|
|
|
Re: SPL and dBs, what can I hear?
|
Joined: May 2002
Posts: 10,654
shareholder in the making
|
|
shareholder in the making
Joined: May 2002
Posts: 10,654 |
Blake, welcome. One point to keep in mind is that the frequency response curves are often measured in an anechoic chamber(rather than a room)which, depending on its size, doesn't give accurate results below about 80-90Hz. So, don't attempt to use those graphs to judge the low bass under 100Hz, since it will vary significantly when in-room reinforcement is present.
As has been mentioned, 80dB is actually a fairly loud level(ordinary conversation is maybe 60-65dB), and is about what I refer to as "comfortably loud". Even quiet rooms at home would have a background noise level of at least 40dB, so music would have to be louder than that to be even audible above the background.
-----------------------------------
Enjoy the music, not the equipment.
|
|
|
Re: SPL and dBs, what can I hear?
|
Joined: Jan 2007
Posts: 4
newbie
|
|
OP
newbie
Joined: Jan 2007
Posts: 4 |
thanks for all the responses/advice. i guess i'll just have to bite (or buy) the bullet and try a pair out in my house. i would love to add a sub to a pair of M3s or M22s but my wife has a strict upper limit of only 2 subs per household so i'm currently maxed out.
I also have a question about room layout and speaker placement but i think i'll start a new thread on it.
later.
blakelock
|
|
|
Re: SPL and dBs, what can I hear?
|
Joined: Oct 2006
Posts: 6,955
axiomite
|
|
axiomite
Joined: Oct 2006
Posts: 6,955 |
Quote:
So, don't attempt to use those graphs to judge the low bass under 100Hz, since it will vary significantly when in-room reinforcement is present.
True enough. However, I wonder if for comparative shopping purposes, it still might be useful considering that, after purchase, both would end up in the same room and would be effected equally by the surroundings.
For subtle to small differences, the room may create or cancel something in one speaker but not equally to another creating an unfair comparison, methinks. However, for a basic buyer, a major discrepancy in two speakers graphs could still show that one speaker has no chance to do deep base while another is more likely to succeed. For instance, one could probably safely use graphs of say, an m80 verses some bookshelf being pushed in a big box store that simply hasn't got the driver size to go below 100Hz. (It might be a wonderful speaker at it's design levels but was simply engineered to be accompanied by a sub to get lower than that.)
I definitely agree with the point you made but wouldn't want it misinterpreted by a newcomer that the low ends of graphs are not worth looking at although it's a question to see if I'm correct as much as a statement.
With great power comes Awesome irresponsibility.
|
|
|
Re: SPL and dBs, what can I hear?
|
Joined: Apr 2007
Posts: 68
old hand
|
|
old hand
Joined: Apr 2007
Posts: 68 |
Quote:
My point was, in general, what would be a good rule-of-thumb cutoff to gauge a speaker's performance based on it's frequency graph? ...for a given frequency, is a 10 dB drop "a lot" or or will i still hear reasonable output at that frequency?
Blake,
The general industry standard for a comparative reference usable (flat) frequency response of speakers is +-3db (at 1 meter-on axis).
Yes, a 10db drop is a lot (usually found on the extreme, top\bottom end responses) and is generally not considered adequate acoustic output of the speaker system. It is there, but due to the higher db output of the total speaker system, it is very hard to hear and perceive. A 3db increase or decrease is where most people can detect an audible change...some are much more sensitive to as little as a 1db change. However, a 10db increase or decrease of acoustical amplitude is usually perceived as twice as loud or twice as soft. Thus, a 10db drop of a speakers end responses is "masked" by the overall higher average output of the system!
As others have stated, in-room responses, especially in the low-mid bass regions, can be reinforced by room boundaries and extend the usable frequency range of what is heard\measured! That can be good, or bad...depends on the quality and tonality of the boundary reinforcement. Electronic equalization can also "extend" the usable response of the system, but most often causes other undesirable auditory effects.
Hope this helps! 
Ted
Samsung 67" DLP 1080P * 2-Axiom EP500 PSW's * Emotiva UT Series Amps * Acoutimass 15's 5.1 = WOW!
|
|
|
|
Forums16
Topics24,943
Posts442,465
Members15,617
| |
Most Online2,082
Jan 22nd, 2020
|
|
|
0 members (),
558
guests, and
4
robots. |
|
Key:
Admin,
Global Mod,
Mod
|
|
|
|
