Speaker Placement - AVS Forum | Home Theater Discussions And Reviews
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post #1 of 10 Old 12-11-2013, 01:59 PM - Thread Starter
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Unfortunately I will need to place my speakers fairly close together. Bought this TV stand to be able to put speakers in since I have no room on the floor.


Front Speakers: Pioneer SP-BS22-LR
Center: Pioneer SP-C22



Which of the two setups would work best:

First Setup:




OR


Would this be better:
Second Setup:




I am looking for what will sound best and acoustically correct with the options available to me.

The reason for Setup 1 was obviously so that all channels would be at the same/ear level.
The reason for Setup 2 was that since the speakers are so close together, I didn't know if it would be better to create some center channel separation.

Thanks in advance.
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post #2 of 10 Old 12-11-2013, 07:48 PM
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If they were my only two opinions...I would go with the first one.
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post #3 of 10 Old 12-11-2013, 08:16 PM
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Neither, you are putting your R and L in a box, then laying them sideways.
They also are rear ported....




Where to start....
1) They were designed to be standing up, their dispersal pattern will be all wrong on the side.
(In another thread I posted graphic to explain it, can't find and show that easily with mobile device)
[edit - via desktop here is more info]
https://www.avsforum.com/t/1496562/help-with-speaker-setup#post_23878828
Quote:
Originally Posted by mtbdudex View Post

Quote:
Originally Posted by mijotter View Post

What are the repercussions of a horizontal setup as far as sound to my ears is concerned? Will it sound muffled, unlocalized, etc?

Also, I noticed you're in SE MI. I lived in Adrian for quite a while

Imagine this; you mids/hi freq are being dispersed in a designed pattern, sprayed out mostly side-side, and as you go up/down it tapers off.
s

so, when you turn your speakers sideways, you are having a central "hot" area directly forward of the speaker - on center....and inducing un-wanted reflections also off the ceiling/floor.....

So, with that image what do you think would happen as you move side-side off center of the speaker that is now sideways?
(if I tell you then you are not learning....)

2) Putting them in a box will also change their baffle step compensation from what the crossover is designed for.
(This will affect the center as well)
Sorry, but that's the law of physics and acoustics.

[edit- here is a good read on that]
https://www.avsforum.com/t/1488412/would-something-like-a-seos-fusion-alpha-karma-diy-work-well-in-a-baffle-wall#post_23685795
Quote:
BSC made simple (and why it may be important to you)

by JIM SALK
in SPEAKER DESIGN
While baffle step compensation (BSC) sounds complicated, it is really quite simple once you understand what happens when sound waves emanate from a speaker. Here is a slightly over-simplified explanation:

the nature of sound
Sound, by its very nature, wants to travel in all directions. When sound is generated by the woofer in a speaker, for example, that sound not only projects forward to the listening position, but also travels around to the rear of the speaker.

You can confirm this with a simple experiment. Stand behind a speaker and you will still hear sound, although note that the highs will be lacking.

Congratulations, you have just unlocked the key to understanding the mystery of BSC! Let’s look at what is happening here.

details
What happened to the high frequency sounds? In short, they were reflected forward when they bounced off of the front baffle of the speaker.

This phenomenon is related to the wavelength of the sound at various frequencies. Just so you don’t have to do any math, here is a rough table (bear with it…this will not get too technical):

Frequency
Approx. Wavelength
20,000 Hz
.67″
10,000 Hz
1.35 “
5,000 Hz
2.7 “
1,500 Hz
9 “
1,000 Hz
13 “
750 Hz
18″
440 Hz
(A above middle C)
30 “
I have highlighted two entries in the above table. We will see why in a moment. And you will understand the theory behind BSC when that moment arrives!

baffle width and BSC
Let’s take a look at what happens when sound is generated by speaker drivers that are mounted in the middle of a baffle that is 9″ wide.

When the 20,000 Hz signal in the table is generated by the tweeter, it tries to move in all directions. But after one wavelength, it has traveled only .67 inches. So although a portion of the energy tries to move to the rear of the speaker, it can’t. It hits the front baffle and is reflected forward towards the listener. The same is true of the 10,000 Hz and 5,000 Hz signals in the table.

The 1,500 Hz signal (highlighted), on the other hand, has a wavelength of 9″ and reaches the edge of our 9″ baffle where diffraction can actually cause a slight rise in response levels at the listening position. At 750 Hz (also highlighted), the sound actually begins to travel around to the rear of the speaker.

So basically, any frequency lower than 750 Hz will be able to travel around the speaker (creating a roll-off of 3db for two octaves at the listening position), while frequencies above that will not. You heard this in the listening experiment above.

Note that increasing the width of the baffle will simply reduce the frequency where this behavior difference occurs. So BSC must be designed for the specific baffle in question.

the problem
OK. So, in our example, most of the sound at frequencies above 750Hz is directed forward toward the listener. Sounds at lower frequencies are not only directed forward, but also pass around the speaker to the rear. In fact, nearly half of the sound pressure is lost to the rear of the speaker.

So think about this: if the tweeter and woofer generate the same volume, high frequencies will be twice as loud as low frequencies at the listening position. (While this sounds like a huge difference, keep in mind that a doubling of sound pressure is about the smallest volume differential humans can detect.)

At any rate, the result at the listening position is sound that will be thin and lacking in the bottom end.

the solution – BSC
The solution is to design a circuit in the crossover that shapes the sound to compensate. It basically rolls off the higher frequencies so that they are in line, volume-wise, with the lower frequencies at the listening position. Baffle step compensation saves the day!

You should now understand the theory behind baffle step compensation. Congratulations!

but…
What happens when you mount this speaker in a wall?

Well, you have now increased the width of the front baffle. It now becomes the entire wall surface, so you have essentially created a baffle of infinite width. In this case, even the low frequencies cannot move to the rear of the speaker.

Since you rolled off the highs with BSC, you will now have too much low frequency energy directed forward. The result will be a boomy, uncontrolled bottom end.

The same would be true, although perhaps to a lesser extent, if you backed the speaker up to the wall. In both cases, an excess of bass energy (in relation to higher frequencies) is directed at the listening position.

This is why speakers designed to be free-standing (which require BSC) should not be mounted in a wall.

congratulations!
You now have a working understanding of baffle step compensation. Your friends are bound to be impressed, but as to whether that is in a positive or negative fashion remains to be seen. You are now officially a “speaker geek.”



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post #4 of 10 Old 12-11-2013, 08:32 PM
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Quote:
Originally Posted by mtbdudex View Post

Neither, you are putting your R and L in a box, then laying them sideways.

Where to start....
1) They were designed to be standing up, their dispersal pattern will be all wrong on the side.
(In another thread I posted graphic to explain it, can't find and show that easily with mobile device)

2) Putting them in a box will also change their baffle step compensation from what the crossover is designed for.
(This will affect the center as well)

Sorry, but that's the law of physics and acoustics.


Via my iPhone 5s using Tapatalk

He probably would be better off using 3 smaller vertical speakers and a sub if he has room and use the first setup.

TV - LG 65B7P OLED / Receiver - Yamaha RX-A1040 7.2 / Blu Ray - Oppo BDP-83 / Turntable - Technics SL-3300 / Cable Box - Comcast X1 V4 4K /L & R Paradigm Studio 20 V3
Center - Paradigm CC-470 V3 / 4 Surrounds - Paradigm SA-15 V3 In Walls
Subwoofer 1 - Sunfire HRS-12 / Subwoofer 2 - Paradigm PW-2100
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post #5 of 10 Old 12-11-2013, 08:39 PM
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His speakers are fine - since he owns them, just put them on speaker stands, either buy some or DIY, no need to put them in a cabinet.
Keep RH/LH standing up, the center on the side like both designed for.

http://hometheater.about.com/od/loudspeakerreview1/ss/Pioneer-Sp-pk22bs-Compact-Home-Theater-Speaker-System_3.htm
They are not really sensitive speakers at only 85db, but for avg listening levels they'd be ok
Quote:
1. Frequency Response: 55Hz to 20KHz.

2. Sensitivity: 85 dB (represents how loud the speaker is at a distance of one meter with an input of one watt).

3. Impedance: 6 ohms (can be used with amplifiers that have 8 ohm speaker connections).

4. Drivers: 4 inch Woofer/Midrange, 1 inch Tweeter, Rear Port.

5. Power Handling: 80 watts maximum.

6. Crossover Frequency: 3kHz (represents the point where signal higher than 3 KHz are sent to the tweeter).
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post #6 of 10 Old 12-11-2013, 09:41 PM - Thread Starter
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I will look into incorporating stands but if I can't get them to fit, does everyone concur with Setup 1?


What if I cut out the backs of the cabinet portions/cubes where the speakers will be? Will this help so that there is no back to bounce off of? Also, not sure if this will help cut it down, there is only about 7 inches of dead space behind the speakers.


Lastly,
What if I did something like this and put in the cotton to cut down on the bass that may be created from the shelves?
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post #7 of 10 Old 12-12-2013, 10:51 AM
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Mikex - what about speaker stands makes them "hard to fit?" into your listening space?
Not clear at all. Post a picture, cell phone pict is fine.

Does your AVR have a speaker set-up page?
If so, read it.

Shoving cotton into the rear is essentially making a port plug, again you are changing the intended design and engineered characteristics of the speaker.....why do you want to do that?
Something like that is better to do via crossover points and integration with your subwoofer, and if your AVR has auto-eq routine that may also help.

Also - there is a good sticky right here in this forum, have you read it?
Look at some of the links on speaker layout & placement.....
Setting Up Your Home Theater 101
Quote:
Speaker Layout

Audioholics - Speaker Placement: Setup Tips for Upgraded Home Theater Systems
Audioholics - Loudspeaker Placement Guide
Audioholics - Home Theater Speaker Layout - An Essential Guide
Audioholics - Speaker Spikes and Cones – What’s the point?
Audioholics - Vertical vs Horizontal Center Speaker Designs
Bob Golds, Sanjay Durani - Dipole Surround Placement
Dolby Speaker and Room Setup
DTS - Where Should I Place My Speakers?
Loudspeakers and Rooms for Multichannel Audio Reproduction, Part 1 by Floyd E. Toole from Harman
Loudspeakers and Rooms for Multichannel Audio Reproduction, Part 2 by Floyd E. Toole from Harman
Loudspeakers and Rooms for Multichannel Audio Reproduction, Part 3 by Floyd E. Toole from Harman
THX 5.1 Speaker Layout
THX 7.1 Speaker Layout


For reference, here is mine, it shows having the front soundstage R/C/L and even front wides tweeter at ear height if at all possible.
11.x%2520speaker%2520layout%2520via%2520Denon%2520Manual.JPG
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post #8 of 10 Old 12-12-2013, 11:08 AM - Thread Starter
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I will take a pic when I get home. As far as space, I mean physical limitations. I know where to set-up pictures, never thought that a cabinet would be an issue. This is my first good set of speakers.

I guess only other question would be why doesn't Audyssey Acoustic Correction and the DynamicEQ account for situations like these? Shouldn't hear the audio may be boomy and knock down the bass?
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post #9 of 10 Old 12-12-2013, 12:11 PM
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Maybe a solution....
How wide is your tv?
Can those bookshelf R/L go on the top of your cabinet?
I assume your AVR, cable box, blu ray, game condole, etc can go in the shelfs.

Best is If your tv is on a wall mount then you can also put your center directly below it, and the R and L spread out on the top shelf sitting correctly orientation.

Next q is forming an equilateral triangle you and R and L speakers...
Hence I posted that sticky with speaker set up.


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post #10 of 10 Old 12-12-2013, 01:39 PM - Thread Starter
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Quote:
Originally Posted by mtbdudex View Post

Maybe a solution....
How wide is your tv?
Can those bookshelf R/L go on the top of your cabinet?
I assume your AVR, cable box, blu ray, game condole, etc can go in the shelfs.

Best is If your tv is on a wall mount then you can also put your center directly below it, and the R and L spread out on the top shelf sitting correctly orientation.

Next q is forming an equilateral triangle you and R and L speakers...
Hence I posted that sticky with speaker set up.


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It could but the center wouldn't clear.
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