A seminar/ Webinar on room acoustics and placement of speakers

[sud98]

Wonderful idea Prem! My setup is temporary and going to be relocated shortly. I solicit other interested members to post pics.

This is my HT room in my new house. It would be lovely to get feedback and inputs on the same. The dimensions are 15*12*10 (L*W*H) in feet. This is in the basement of the house, so there are no windows.

Besides thick carpet on the floor, everything else is to be decided. I know I will need to invest in bass traps in the corner and possibly handle first reflection points (for audio use). All inputs welcome, will add more information if needed.

 

[captrajesh]

By moving the speaker in the room we are not doing anything to the frequency response but only altering the phase so that it sounds right at all positions without any sweet spots.

Are you sure Hari!? I thought moving speakers closer to wall accentuates the LF response!!

 

[Hari Iyer]

Are you sure Hari!? I thought moving speakers closer to wall accentuates the LF response!!

Moving closer to wall increases spl @ LF but does not alter the FR. its again modfying the phase only imo.

 

[keith_correa]

When the SPL at any frequency attenuates or increases, it affects the overall frequency response. Another part is phase.

 

[Hari Iyer]

Is FR = function of (SPL) or SPL = function of (FR)?

 

[sound_cycle]

Moving closer to wall increases spl @ LF but does not alter the FR. its again modfying the phase only imo.

Absolutely not pretending to be any kind of expert but position (speaker and/or the listener) can affect both the "perceived" frequency response and the phase.

Let me hasten to add since I said perceived, no psychology involved both of these can be measured and quantified. I am also not saying that a frequency attenuation because of the room causes phase to be affected.

Mitigating only one (for example using parametric equalizers) is not enough for an uncolored stereo listening experience.

ciao
gr

 

[keith_correa]

2 ways to interpret this:

Doesn't affect the frequency response
>>>Yes, from a purely speakers perspective. The FR of the speakers does not change based on the speakers placement in the room.

Affects the frequency response
>>>Yes, from the listeners perspective. Because we listen to the speakers AND the room, both.

 

[Hari Iyer]

I am confused again -

If FR of a speaker is 50Hz-20KHz (-10dB SPL reference) 4 feet away from the wall after moving the speaker one foot away from the wall will the freq response become 20Hz-20KHz (-10dB SPL reference) or will it still be 50Hz-20KHz (-6dB SPL reference)?

 

[saikatbiswas82]

I think we are talking about reflection here.

The speaker will definitely produce same frequencies no matter where it is placed. IMHO. YMMV.

Sent from my Nexus 5 using Tapatalk

 

[keith_correa]

The speaker will definitely produce same frequencies no matter where it is placed. IMHO.

Correct! Which is what I said too. But what we ultimately hear is the speakers + the effect of the room. Unless, one's listening room is an anechoic chamber in which case I am wrong.

 

[philipreji]

The inherent frequency response of a speaker does not depend on its placement in the room.

 

[srisaikat]

I hope it's not too late........ if it is Web-based seminar then I am in. Please let me know if there is any other special requirement apart from broadband connection.

 

[desertfox]

Please add me too captain! Just chanced upon this thread by pure lack. God I would have kicked myself if I missed out. Thanks for initiating this!

 

[Kannan]

Any update on this webinar?

 

[Eddierockks]

Just came across this thread and want to be a part of this webinar if it hasn't happened already. Update on this please

 

[soundbuff]

Hello Folks,
Is this going anywhere? Its been a couple of months since the first post from the initiator captainrajesh. Or have I missed out on the event?

 

[sound_cycle]

Hi

I am hoping this link is completely bang on topic (of listening to speakers in rooms and hopefully figuring the whys? and what tos), interesting and informative. I would also like to thank the hfver who complimented me on my ignorance about target curves and (probably) envied the bliss it resulted in via pm. That started off a line of inquiry which I had previously missed. I of course, am not contesting the accuracy of that statement, merely acknowledging its truthfulness.

"The B&K target was formally presented to AES in 1974, and sound engineers were already aware and using similar type curve since the 1950s or earlier.] A flat response will sound like shit at the listening position" . Additional detail and linky below
I came across this on SBAF (What is Neutral Frequency Response | Super Best Audio Friends)

"An objective angle is another; but it needs to be supported by the subjective observations. Amps and DACs should always measure flat more or less. If the equipment is not for pro-use (where it would be slotted in long chains of other gear), a little roll-off at the extremes would be OK and probably imperceptible. Distortion and other non-linear characteristics are going to have a larger impact on sound, even in the perceived tonal balance sense, than 1.5 db roll-off at 20kHz.

For transducers, depending upon the measurement method used, there should always be a target response to achieve neutrality. A flat line isn't necessary that target. At the listening position with speakers, the target response I like is the old B&K target (http://www.bksv.com/doc/17-197.pdf) see page 4."​

(emphasis added) I note that like that kind of a target curve.

Adding here instead of an separate post : re the all important cables in your head (from TEGs signature) How The Ear Works | Sound On Sound. I guess though that he has already read this one "The most important pieces of hardware in any studio are the ones on the sides of your head. In this article, we're going to have a close look at the tool we all use every day: the ear. This small organ has quite a few surprises in store for us. We' see that it's literally crammed with equalisers and dynamic compressors, including a multi?band one. It even includes an extremely efficient filter bank, as well as a highly sophisticated analogue?to?digital converter. Armed with this knowledge, sometimes referred to as 'psychoacoustics', we'll discover numerous practical consequences for music production"

ciao
gr

 

[sud98]

Re: A seminar on room acoustics and placement of speakers

Reviving an old thread which died due to various reasons.

While the original idea was a webinar so that more people can gain the benefit of the same, I think (as suggested by a few FM's) a physical seminar has far more benefits esp. if we can manage to showcase live demonstrations of the same.

So here our a few suggestions

1. We use someone in the commercial side of acoustics like Anutone to provide their auditorium. (They had done so for a generic meet a few years back).
Its a win-win for both as they can talk about their products and we get infra to host this plus some gyan from some experts.

2. We have FMs to talk of the theory and application of acoustics and placement for both stereo and HT setups. This is is the difficult part as we still need volunteers for the same.

3. We have a session on measuring by ear and measuring by equipment. For the equipment piece, we have a FM who has a callibrated UMIK and REW and I am hoping he or someone else can use for the same.

4. Any other topics.

Please drop in your ideas if you think this is feasible and even more important will anyone volunteer for individual topics.

Also, I havent talked to Anutone yet, if anyone knows the founders it would be easier to push this through.

P.S. - We can record the same and upload it, although the quality of audio tends to deteriorate in youtube for the benefit of others.