Order of Importance with setup?

[rolyasm]

Thanks in advance for your replies. I have built a dedicated HT room. It will be two rows of seating. The back row of seating is on a riser, abour 20" high. In the riser I have mounted 4 15" subwoofers. I have purchased a Behringer Feedback destroyer to help me EQ the sub, and I have the amp ready for the subs. I also have an AV Processor so I can feed info to my subs. I can't afford all my gear at once, so I thought I would get the subs up and running and then start on the other equimpent. My question is this. In what order should I proceed with room treatments, Sub EQ, and anything else? I have equipment (Audio card, Mic, SPL meter and software like Room EQ Wizard) to test things, but have never used the program before, so I don't really know what it is capable of. So... do I measure the room first, add treatments, bass traps, those sort of things, then get my subs up and going, or do I have to have my subs running to see how the room is affecting the subs before I do the treatments? Kind of a chicken and egg thing. Just not sure where to proceed from here. Thanks. Also, what software would I use for each of the processes? Links would be very helpful.
Roly
Here are some pics of my subs. All I need is the covers. Not sure if I like the cover I have below.

 

[mtrycrafts]

Thanks in advance for your replies. I have built a dedicated HT room. It will be two rows of seating. The back row of seating is on a riser, abour 20" high. In the riser I have mounted 4 15" subwoofers. I have purchased a Behringer Feedback destroyer to help me EQ the sub, and I have the amp ready for the subs. I also have an AV Processor so I can feed info to my subs. I can't afford all my gear at once, so I thought I would get the subs up and running and then start on the other equimpent. My question is this. In what order should I proceed with room treatments, Sub EQ, and anything else? I have equipment (Audio card, Mic, SPL meter and software like Room EQ Wizard) to test things, but have never used the program before, so I don't really know what it is capable of. So... do I measure the room first, add treatments, bass traps, those sort of things, then get my subs up and going, or do I have to have my subs running to see how the room is affecting the subs before I do the treatments? Kind of a chicken and egg thing. Just not sure where to proceed from here. Thanks. Also, what software would I use for each of the processes? Links would be very helpful.
Roly
Here are some pics of my subs. All I need is the covers. Not sure if I like the cover I have below.

I would say start by measuring first to see what problems you have and how bad. Maybe that sub EQ will be enough?

 

[rolyasm]

Mtrycrafts,
Thanks for the reply. You say you would start by measuring first. What would you measure first? Sorry, I have never done this. Are you saying you would meaure the sub first and EQ and see if that is enough? Or measure the room first, use EQ on the sub and see if that is enough? Also, I think I understand the process of measuring the sub response by plotting a frequency graph. Is the Room EQ wizard meant to only test room response. All I have hooked up so far is my subs, due to lack of funds. Will this be enough to test the room for needed treatments, or do I need a set of full-range speakers to run tones and such through?
Roly

 

[Ethan Winer]

Roly,

> In what order should I proceed with room treatments, Sub EQ, and anything else? <

The path to great sound is, in order (assuming competent equipment):

* Speaker and listener placement
* Room treatment
* EQ

> do I measure the room first, add treatments, bass traps, those sort of things <

Measuring is not really needed except maybe to help adjust a sub EQ or to confirm that what you did really did make things better. The main reason I suggest someone measure their room is only so they can see how bad it is without treatment.

--Ethan

 

[rolyasm]

I just finished reading the Acoustics 101 pages on this forum. Good Stuff. I should have taken the title's advice and read it first. I still have some questions. So since I am poor and I don't have my speakers yet, only the sub, I guess it is kind of pointless to test the room? I was under the impression that whatever speaker I put in the room would be affected the same way by the room. So if I use Polks, or M&K, or whatever, I would be utilizing treatments in the same way with all kinds of speakers. Isn't this wrong? I think now that each speaker has different sets of dispersions, frequencies and so forth that will interact differently, causing the room to respond differently? Is this right? If so, then it makes sense to wait until I get my speakers to test the room. I guess part of the confusion comes into play in that I know there are programs where you put in your room dimensions and from that you can guess how the room will respond to certain frequencies and such. I assumed you could use this information to treat your room. I know companies like Rives will help you setup your room and do treatments, but don't they do this over the phone/online using only meaurements you send them? If this is so, then maybe I don't need to have my speakers in place to start adding treatments. So.... 1)can I begin treating my room with traps and things before I get my speakers in, and if so, 2)how? I do have some older polks I could throw in there to pass tones if needed. thanks
Roly

 

[Ethan Winer]

Roly,

> I don't have my speakers yet, only the sub, I guess it is kind of pointless to test the room? <

Yes, there's nothing to test yet if you don't have any loudspeakers!

> I was under the impression that whatever speaker I put in the room would be affected the same way by the room. So if I use Polks, or M&K, or whatever, I would be utilizing treatments in the same way with all kinds of speakers. Isn't this wrong? <

The room affects what you hear even more than the speakers - assuming competent speakers. But the same treatment works with any speakers. I've had three different sets of speakers in my living room home theater over the past two years, all with (mostly) the same acoustic treatment. The only thing that might vary is the location of first reflection panels, but that's only if the different speakers are in different places.

> can I begin treating my room with traps and things before I get my speakers in <

Yes.

There's a lot of info in the 101 section here you mentioned, and there's also plenty of basic and advanced information on my company's web site, and yet more in my Acoustics FAQ:

www.ethanwiner.com/acoustics.html

--Ethan

 

[bpape]

I'd agree with Ethan's ordering of priorities. In order to get started down that path though, you need to have the subs up and running. What you may do in terms of speaker placement may be completely different with the subs in play.

Also, any specific non-broadband or broadband bass only treatments may change their tunings.

Bryan

 

[WmAx]

The treatments that are optimal are dependant on also on the polar radiation pattern of the speaker. Scientifically valid, peer-reviewed perceptual research by Dr. Floyd Toole suggests that the amount of room treatment depends heavily on the polar response pattern(s) of the particular speaker(s) in question. What this means is that what may be optimal for speaker X may actually degrade the overall sound quality of speaker Y. To put it plainly, the worse the off axis response linearity is compared to the on-axis response, the more absorption/diffusion of the 1st reflections is desired. But if you over-damp the reflections(assuming the reflections are of sufficient time delay, of course), the sound quality may be reduced. For an extreme example: a full-range omnipolar would not optimally use the same amount of absorption/diffusion at the reflection points as compared to an ESL. However, most speakers share a somewhat close polar response, therefor the treatments that are optimal are usually the same for most speakers. In some cases, a select few people may always want what is the equivalent of a totally dead environment(making their speakers basically sound like near field monitors) regardless of speaker used, but this is not shown to be the normal preference.

-Chris

 

[mtrycrafts]

Mtrycrafts,
Thanks for the reply. You say you would start by measuring first. What would you measure first? Sorry, I have never done this. Are you saying you would meaure the sub first and EQ and see if that is enough? Or measure the room first, use EQ on the sub and see if that is enough? Also, I think I understand the process of measuring the sub response by plotting a frequency graph. Is the Room EQ wizard meant to only test room response. All I have hooked up so far is my subs, due to lack of funds. Will this be enough to test the room for needed treatments, or do I need a set of full-range speakers to run tones and such through?
Roly

Well, the whole point is to measure the speaker and room interaction. So you would measure them both.
I would be very hesitant to apply room treatment before you know what the problems are. Fixing the car. Do you start fixing it without knowing what is wrong with it?
Since you only have the sub, check that out and since you have an EQ, see if it helps bring the sub into better response, flatter. You may or may not need an eq for the main speakers when you get them. EQs are your friend. They are used in studios even after they are treated.

 

[Glenn Kuras]

If you are going to be testing your room you may want to look into the ETF software. You can shoot the room in about 5 seconds.

Glenn

 

[Ethan Winer]

> I would be very hesitant to apply room treatment before you know what the problems are. <

Yes and No. All rooms need as much bass trapping as possible, and they also need first reflection treatment. Chris has a good point about some speakers needing a wider "zone" than others. But the basics are the same for all rooms. I have never seen a room that was not greatly improved with bass traps in each of the four corners plus RFZ panels on the side walls.

What does vary from room to room is how much mid and high frequency absorption is needed.

--Ethan

 

[Vaughan Odendaa]

Hi Ethan,

Since you have extensive experience with ETF software perhaps you could answer this question for me. Is it really easy to use, I'm talking about the basic functions here, like measuing FR and modal ringing, or is there a steep learning curve ?

Just would like to know. I have posted my FR results somewhere here using your test tones up to around 170 hz. Yikes ! Too long.

To the poster,

Once you have your speakers, it might be wise to invest in software to measure your frequency response quickly as Glenn pointed out on page one. Measuring one frequency band at a time is time consuming task.

Cheers.

--Sincerely,

 

[ScottMayo]

I'd buy or build bass traps - they are not fun to build - and get your speakers in. Don't worry about measurements until you have all your speakers wired up, and are in a position to experiment with moving them around. Measurements you take with just some of the speakers working, often won't stay valid. Since you'll need bass trapping in any case, you might as well put it in first and do your measurements, if any, after that.

Don't fuss too much over measurements, unless you're looking for end all and be all audiophile experiences. A decent HT can be tuned by ear, unless you have unusually fussy requirements.

 

[Ethan Winer]

Vaughan,

> Is it really easy to use, I'm talking about the basic functions here, like measuing FR and modal ringing, or is there a steep learning curve ? <

It's neither "really easy" nor "steep learning curve." The most difficult part for most people is getting their computer's sound card connected, and second most difficult is figuring out how to interpret the graphs. Personally, I agree with Scott that measuring is not the most important thing. Mostly because no matter what you measure, the solution is always the same: broadband bass trapping that works well to as low a frequency as possible.

The main reason I tell people to measure their room is just so they'll see how bad it really is. I am serious! Most people have no idea how bad their room is, so the first step is simply to get them to understand that. Another reason to measure is to see how much the response and ringing were improved after adding bass traps. But unlike fancy speaker wires and magic isolation pads, the improvement after treating a room is very obvious.

--Ethan

 

[bpape]

I recommend measuring the room with no treatments in it first. The reason is that it's MUCH easier to hear the differences and find the optimal placement for speakers, subs, seating, etc. That allows you to get as good as you can get first, then you deal with what needs to be fixed.

Yes, there are some things that all rooms require - I'd agree. The trick becomes how much, of what, and where.

Bryan

 

[Glenn Kuras]

Ethan,

>It's neither "really easy" nor "steep learning curve." <

Tell me about it and thanks for helping me out with the one customer that could not seem to get things set up right!!

Bryan,

>I recommend measuring the room with no treatments in it first. The reason is that it's MUCH easier to hear the differences and find the optimal placement for speakers, subs, seating, etc. That allows you to get as good as you can get first, then you deal with what needs to be fixed.

Yes, there are some things that all rooms require - I'd agree. The trick becomes how much, of what, and where.<

I could not agree more with this. Also it helps to know when you are starting to get to diminishing returns on bass traps.

Glenn

 

[WmAx]

Waterfall response of low frequency is of technical use, but it should be noted that waterfall chart of low frequency response can not be correlated to audibility, because to my knowledge, no credible perceptual research has been conducted and published on low frequency resonance(s) in order to make this possible. Also, things can look different than how they actually sound; it follows known human bias of perception, that looking at a chart may actually induce psychological influence to alter what/how you perceive. If anyone here can refer me to credible, peer-reviewed research that correlates low frequency resonance parameters to human audibility via human subject control tests, please give me the reference(s).

-Chris

 

[Ethan Winer]

Chris,

> waterfall chart of low frequency response can not be correlated to audibility, because to my knowledge, no credible perceptual research has been conducted and published on low frequency resonance(s) in order to make this possible. <

I don't see the relation. Just because nobody has yet conducted a formal study doesn't mean there's no relationship! I can hear the effects of modal ringing very clearly and obviously, and I'm sure you can too. It's the main cause of the effect known as "one note bass," where every bass note sounds more or less like every other one. This happens because the ringing imparts its own character onto every note. You can hear this clearly at higher frequencies if you play around with percussive instrument sounds through a parametric equalizer.

> it follows known human bias of perception, that looking at a chart may actually induce psychological influence to alter what/how you perceive. <

Agreed. There is an awful lot of "placebo affect" in high end consumer audio, and even among audio pros who should know better.

--Ethan

 

[WmAx]

I don't see the relation. Just because nobody has yet conducted a formal study doesn't mean there's no relationship!

Perhaps I should have stated that no correlation can be shown to weight the degree of audibility with a specific resonance to human subjects. I did not necessarily mean that no relation existed to resonances, but that no studies exist to my knowledge, that demonstrate the degree of audibility(or inaudibility) of particular frequency vs. relative resonance bandwidth and amplitude. When such research is produced, one can intelligently use the measured results to more accurately approach the situation(s). The perceptual research on higher frequency resonances, as done by Fryer in the 70's, and later refined by Floyd Toole at Harman in the 80's, and the subsequent application to loudspeaker driver/cabinet/system design, is a prime example.

In fact, because of the lack of LF resonance research, I may be interested in helping produce some control tests to at least start to develop some preliminary coorelation. Such testing should be performed with a system that has little to no bass resonance characteristics, so that the effects can be controlled and applied to test signals/tracks in the electronic realm. Any actual loudspeakers placed in a room[even very highly treated] would probably be unsuitable, due to the unavoidable resonances that will exist to some degree, that may mask the testing. Probably a headphone with flat LF response is the best solution; it will be void of all room influence. The problem here is that the headphone needs to be measured on the head of each test subject under test using in-ear microphone probes, in order to insure the response is flat, since a headphone can seal differently on different heads, leading to different LF responses. A non-contact headphone like the AKG K1000 may be the answer(with LF eqalization, because I do not believe this product has a very flat LF response extension inherantly), because it does not seal to the head in any way, it sits away from the ears, mounted on a special headband that contacts the top of the head, therefor the LF response should be identical to all subjects.

-Chris

 

[bpape]

When I spoke of measuring first to allow easier tweaking of speaker and seating positioning, I was referring purely about frequency response. Now, realistically, ringing can absolutely affect this.

However, no matter where the resonances end up in relation to the seating position (frequency wise), they do exist. And, they still need to be dealt with. My only point was to be able to find the optimal positioning with just the room, speakers, and seating in place easier and faster.

Bryan