Better imaging

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rockdrummer

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Better imaging
« on: 3 Nov 2017, 02:30 pm »
Hi. I am familiar with absorbers, diffusers, and bass traps on a very basic level. It seems to have made my outlook muddy and overlapping. I know every room is different, but I would think there is a good first step,  I just don't know where it is. I need help.

My speakers are gr research super v, which are full open baffle. I use a bottlehead stereomour tube amp.

My center image is set back. I want to bring it forward and I hope I can get some more pinpoint instrument positioning.  I have a tv and a rack in the front where gear sits. I can make diffusers all around the back, put absorbers in the ceiling and left wall, I have windows on the right wall. 

I know the first response is likely going to be full of questions because it's so hard to give sound treatment advice. Just hoping there is a good idea since I have felt overwhelmed with where to start.

I also don't really know where to start with building a diffuser concerning the frequency. How do I know what frequencies to build from.

Maybe a book that people have used that I can start with.

Ben

Big Red Machine

Re: Better imaging
« Reply #1 on: 3 Nov 2017, 04:34 pm »
You can paradiddle yourself over to a site like this for diffuser design and the frequencies associated with those designs. Or you could flam-a-cue yourself to the GIK site or other vendor sites where they explain more about them.

http://www.subwoofer-builder.com/qrdude.htm

Start slow and experiment. Measurements do help and are fun to take with the right mic, preamp tool, and software like REW.

Early B.

Re: Better imaging
« Reply #2 on: 3 Nov 2017, 05:44 pm »
You can get better imaging by optimizing speaker placement, especially with open baffle speakers.

What are the room dimensions?

How far are the speakers pulled away from the front wall? How far are the speakers from the side wall.

How far is the seating position from the back wall?

Wind Chaser

Re: Better imaging
« Reply #3 on: 3 Nov 2017, 05:59 pm »
You can get better imaging by optimizing speaker placement, especially with open baffle speakers.

What are the room dimensions?

How far are the speakers pulled away from the front wall? How far are the speakers from the side wall.

How far is the seating position from the back wall?

 :thumb: :thumb: :thumb: :thumb: :thumb:

Could not have said it better.

SoCalWJS

Re: Better imaging
« Reply #4 on: 3 Nov 2017, 06:00 pm »
You can get better imaging by optimizing speaker placement, especially with open baffle speakers.

What are the room dimensions?

How far are the speakers pulled away from the front wall? How far are the speakers from the side wall.

How far is the seating position from the back wall?
These are all good questions and will factor in to what direction you may want to go. I've experimented with a wide variety of room treatments with my Super V's (I will say corner traps are right up at the top of the list), yet Cheeseboy's sound better in his untreated room than mine do. Yes, different electronics, but the room itself makes a huge difference. The first time I went to his place and took some basic measurements with OmniMic, and saw how much better his room was than mine, I knew I was facing an uphill battle.

If I'm reading the original post right, and you have your equipment and a TV in between your speakers, that is problematic - and I'm in the same position. No other realistic choice. Try to figure out someway to pull the speakers slightly out in front of the equipment and TV and place an absorption panel in front of the gear. Makes a BIG difference.

JLM

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Re: Better imaging
« Reply #5 on: 4 Nov 2017, 10:53 am »
Please define for us what you mean by 'imaging'.

Are you asking about an audio or home theater application?

I've found open baffle (dipole) speakers project non-discrete imaging, more of a 'wall of sound' effect.  Vertical arrays by definition cannot image vertically and if they don't extend floor to ceiling cannot produce into the intended 2-dimensional pattern.  So it seems you've found the weaknesses of your speakers.

From my experience putting anything between the speakers blocks the soundstage from developing in the occupied space, so I've always had a very small/low rack.  But moving the gear onto a single shelf spiked to the floor helped immensely. 

Recommend a near-field setup (with monitor style of speakers) that has speakers/listener well away from walls to minimize room effects.  Both parts of this recommendation will also bring the soundstage forward.  I've also found that horn midrange/treble will also provide a 'forward presentation'.

A well shaped room is paramount to good system performance that requires no treatments.  Anything else is a series of bandaids. 

Diffusors are frequency limited by the laws of physics (most are only effective down to 1,100 Hz).  My favorite diffusor recipe is here:  http://www.pmerecords.com/Diffusor.cfm

Recommend reading Floyd O'Toole's "Sound Reproduction" to get a good start into room acoustics.

Rusty Jefferson

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Re: Better imaging
« Reply #6 on: 4 Nov 2017, 12:26 pm »
....My center image is set back. I want to bring it forward and I hope I can get some more pinpoint instrument positioning. .......

Well, that's where it should be, of course, and where everyone else is trying to get theirs. :D  Ideally, all the music should appear to come from behind the speakers, spread across the width of the sound stage, with tremendous depth, and with no music audibly coming from the speakers.  You can probably reduce the depth of the center image by pushing the speakers very close to the front wall, and/or heavily treating the walls/corners behind them to kill reflexions from your OB speakers.  That will reduce the ability to get more pinpoint positioning of instruments, however. They go hand in hand.  If the imaging is 2 dimensional, you can't locate where the instrument is on a sound stage.  OB/dipole speakers are (generally speaking) better at creating depth and a more 3 dimensional sound stage.  Coax drivers in box cabinets will (generally speaking) give you a very focused center image on plane with the cabinets.

rockdrummer

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Re: Better imaging
« Reply #7 on: 4 Nov 2017, 02:38 pm »
Big red-very good use of rudiments! Lol
I don't have any measurements and would need to get more acquainted with that.

Early b- my room is a finished basement, 14 feet wide, opens up about 8 feet in from the front wall, on the left side to about 20 feet. Then runs about 45 feet back.

My listening position is about 12 feet from the speakers. They are 4 feet from the front, and 8 feet apart. I tried to draw a diagram on my phone but that was embarrassing.

I feel like the vocals are the farthest back. I really like the spacious sound. This is my first pair of dipole speakers. I really enjoy their sound.

My 60" tv is up on the wall, and my rack is three shelves. When I get home, I will post some pictures.

I appreciate all the responses, thanks for all your advice and information. Giving advice about someone's room without being able to listen to it is really tough, I know. Especially because I am such a noon.
Ben

rockdrummer

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Re: Better imaging
« Reply #8 on: 4 Nov 2017, 02:46 pm »
JLM, maybe this imaging I'm wanting is also described in other ways, but a 2 dimensional sound display. With my ears, I think there is good left and right separation, but vocals, even though they are coming from the back/center, it seems like a huge area of that front wall is the voice. Maybe that's what people like, but I guess a more pinpoint location is what I want. Also, for other instruments too.

The limited space is going to compress that sound stage, do maybe the examples I've heard before were benefited from a bigger room. Like showroom set ups at stores.

Ben

paul79

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Re: Better imaging
« Reply #9 on: 4 Nov 2017, 04:59 pm »
You want tighter image focus. Yes, the room and its acoustics contribute the most, but your electronics and your speakers must also be capable of providing that nice tight image. Best bet is to take care of that room first. A consult with an acoustics company could help, and speaker placement is best done with experimentation.

ebag4

Re: Better imaging
« Reply #10 on: 4 Nov 2017, 06:35 pm »
Hey Ben, I found front wall diffusion to be very helpful with OBs, that along with speaker positioning including toe in should help quite a bit.  Your amp and speakers are very capable IMHO (I had the V1s and not the SuperV, but they should be more alike than different).  Yes, you can get excellent imaging with OBs.

Best,
Ed

Edit:  I would also try moving the listening chair closer to the speakers, something approaching an equilateral triangle.
« Last Edit: 5 Nov 2017, 02:53 am by ebag4 »

S Clark

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Re: Better imaging
« Reply #11 on: 4 Nov 2017, 06:54 pm »
My speakers are gr research super v, which are full open baffle. ...
Ben
Those speakers were the darlings of the RMAF for a couple of years in a row.  Why not call the guys that set up that room?  No one knows them better.
Danny Richie, who designed your speaker, and Dave Elledge of Pi Audio Group.  I was part of the gopher crew on of those years, and those two did most of the tweaking.  And the GR-Research rooms were always put together as well or better than any other room at the show. 

rockdrummer

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Re: Better imaging
« Reply #12 on: 5 Nov 2017, 05:42 am »
Here is a quick picture of my listening space.


ebag4

Re: Better imaging
« Reply #13 on: 5 Nov 2017, 07:37 am »
That's a nice dedicated listening space Ben. 

The equipment rack between the speakers is high enough it is likely not doing you any favors in the imaging department.  If your cables will allow it, I would try pulling your speakers out further into the space first to see what effect that has, another few feet if possible.  This may give you a better feel for what your equipment can do in the room, if it is positive but you want to move the speakers back closer to what they are currently, you can start adding room treatments to the front wall.  Playing with the speaker distance to listening position may reap benefits as well. 

Something else I found that helped in ways that I didn't anticipate was measuring the room response to get the servo subs set more optimally. Doing this balanced out the system and had a positive impact across the board in my experience.  It may not impact imaging, but the end result surprised me in the overall balance of the system, not just in the lower frequencies.

I see no reason you shouldn't  get great sound in that space, it will take some trial and error as well as some form of room treatment.

Best,
Ed

aln

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Sit closer to your speakers
« Reply #14 on: 6 Nov 2017, 12:18 pm »
Use a reference disc (like Sheffield) to focus the center image.  Try 8 foot back to start.

SoCalWJS

Re: Better imaging
« Reply #15 on: 6 Nov 2017, 03:37 pm »
I would suggest some room treatments on the side walls at the first reflection points as a minimum. You are likely losing some focus due to this.




Not a great photo. but gives you some sense of what they had in place at RMAF.




The panels at the side wall first reflection point.

Wind Chaser

Re: Better imaging
« Reply #16 on: 6 Nov 2017, 04:29 pm »
The last two posts sum up your options. Getting closer to your speakers is a very simple and practical solution but whether or not it is something you can even consider depends on the size and shape of your room and how close you are willing to sit in relation to your speakers. If your room is too small or not wide enough, then room treatments are your next best option.

There is however one other option.... but it means replacing your speakers with other speakers that have constant directivity. Constant/controlled directivity limits the dispersion so that the waves don’t run amuck bouncing off every available surface. And speaking from experience, it makes a huge difference.

gregfisk

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Re: Better imaging
« Reply #17 on: 6 Nov 2017, 06:39 pm »
You have a nice room Ben and you should be able to get it to sound very good. I also have Super V's and my center stage is full and feels very large and not recessed at all. I think you need to be closer to your speakers like Ed mentions, this will give you an equal triangle. I see two ways to do this, bring your speakers closer to your seating position, this will help with your center sound stage by getting in front of your rack which I'm certain is causing you problems with your imaging. If you can't move the speakers closer to you, move closer to the speakers. This should bring your center stage forward and more into the room. Another way to equalize your seating arrangement is to move your speakers farther apart. My center stage is huge with my Super V's but I have my speakers about 6 feet off the front wall and about 3' off the side walls. My rack is on the side wall toward the center of the room so I have nothing in between the speakers. This made a huge different on how my speakers imaged and how well they projected the vocals and instruments into their positions in the room. My room measurements are 20'x30'x10' if that helps with perspective.

Greg

Wind Chaser

Re: Better imaging
« Reply #18 on: 6 Nov 2017, 07:21 pm »
My room measurements are 20'x30'x10' if that helps with perspective.

Now that's a nice size room to work with enormous possibility. If only we all had such space. I'm stuck with a smallish nonlinear room with 7 walls.

I have my speakers about 6 feet off the front wall and about 3' off the side walls.

If you don't mind, how much space is there between your speakers and how far back are you sitting from them?


Rocket_Ronny

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Re: Better imaging
« Reply #19 on: 6 Nov 2017, 09:27 pm »
Oh man, with a room like that I would pull the speakers right out into the room and even farther apart. I like to have 12' behind my speakers if I can do it. Experiment. I would even try having the speakers 6' away, like right in front of the side chair - which I would move, and a foot or so off the side walls as a start and progressively move them back until you get what you want. My room is small and this is how I have it set up.



This is more how I like it. Old room.




Rocket Ronny
« Last Edit: 9 Nov 2017, 04:10 pm by Rocket_Ronny »