# Speaker Placement



## mark3141 (Dec 22, 2014)

I currently have my stereo set up in my living room but am wondering if I'll better SQ by moving it to my downstairs/basement game room. I prefer to have it in the living room, but I'm thinking the layout is not ideal since it's a split level home. Additionally, due to aesthetic reasons, I'm pretty limited on what I can do in terms of re-arranging the room and adding treatment. I'd like to get advice on what I can do to improve the sound quality here, and I'd like to see if it's worth trying to move my equipment downstairs. For example, would minimal treatment with maybe some sort of room correction be beneficial? Ideally, I'm not looking for accuracy so much as the ability to discern separate tracks/instruments and to have a nice, warm sound. (I am generally frustrated when there's a cool track buried in the mix you can hardly hear.)

To give you an idea of the layout, you can see it here and here. The measurements are as follows: 

The wall parallel to the speakers is 182 inches. One wall perpendicular to this is 160 inches with a rather large window covered by curtains/blinds. Past this wall, there is an opening/drop-off which leads to the foyer which is 74 inches wide. All said, the back wall is 234 inches from the opposite wall. As you can see, on the opposite wall, there is are two openings leading to the kitchen. The first is 35 inches from the wall and runs 81 inches. There is then 54 inches of wall before another 31 in opening before getting to the hall-way which is 36 inches wide. To further complicate things, my ceiling is sloped from about 115 near the window to about 136 in at the kitchen. 

When deciding where to place my speakers, I basically tried to put the speakers and listening position at an equilateral triangle. (I'm not sure if that's optimal, but I couldn't find a consensus and just wanted to get started somewhere.) So, currently, I have my speakers 36 inches from the back wall and 54 inches from the side wall. My listening position is centered against the back wall at 91 inches and 125 inches from that wall and 107 inches from the foyer wall. 

I ran REW first without the speakers toed in and again with them pointed at the listener and have attached the waterfall displays from those, as well. I would certainly appreciate any thoughts you may have on this!

Thanks,
Mark


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## Tonto (Jun 30, 2007)

I am truely no expert with REW, I'm sure others will chime in soon. It does look like you have a significant roll off in the higher frequencies. Do you hear (or not hear) that when you are listening to music?


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## mark3141 (Dec 22, 2014)

I'm not 100% sure, to be honest. I'm fairly new to all of this, and I'm trying to be as objective about it as possible. That makes it difficult to really know what I'm seeing or not seeing. 

I do feel as if I'm missing quite a lot. As I mentioned earlier, there are many times where I feel as if various instruments are buried in the mix. This is especially true in listening to a rock or pop chorus (although that may be due to mastering more than anything). On the other hand, sparse acoustic music plays pretty well.


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## robbo266317 (Sep 22, 2008)

A good starting point is to use the golden ratio and then progress room there.

The image below is from the RealTraps site http://realtraps.com/art_room-setup.htm


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## willis7469 (Jan 31, 2014)

They're dead after 10k. That makes me feel like it's a setting, or sound mode thing. What speakers are they and what settings do you use? Try 1/5's and 1/3's of room dims to help smooth the low end of the graph. (2.4, or 4.8 etc is 1/5 of 12' for example.)


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## mark3141 (Dec 22, 2014)

It is a little strange they drop off at 10k. I'm using Usher S-520s/SW-520s. These are a pair of bookshelves matched with a pair of subs, and they're rated for 20kHZ so I'm not sure what the deal is. It must me something in my setup as I've noticed I do not hear the last second or so of the sound sweep. (I have verified it runs from 0-22kHZ.)

I've done a bit more experimenting, and when moving to about 38% from the rear wall as recommended earlier, I consistently had a drop between 100-200Hz. This happened regardless of where I placed my speakers. (Summary SPL is attached.) 

When I use 1/3's or 1/5's, what is that in relation to? Do those apply to the distance from the wall to the listening position, for example? Also, should I use the length of the living room or from wall to wall? As mentioned, I have a a drop due to being in a split level house.


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## tpointon (Mar 18, 2013)

I'm no expert either but I've been doing the same as you for a few weeks so perhaps I might have something useful to say. 

I assume you have a decent (calibrated) mike.

I think the dip around 200 hz is a room mode and from what I can gather, you have to live with it. Elsewhere here I think I've read it is unwise to try to correct for this because the standing waves are cancelling each other regardless of their amplitude. 

The gradual roll-off starting at 2 khz and the cliff at 10 khz are puzzling. If it were me, I would be suspicious that some setting on my receiver needs adjustment. Are all tone controls set to flat? Is there any signal processing engaged (like Jazz / Rock eq settings)? Perhaps you might raise the treble setting on your receiver to see if it makes any difference. 

I think your equilateral triangle arrangement makes sense. I found it makes an improvement getting the speakers away from the wall behind them. Try moving your head fore and aft at the sitting position listening for changes. A foot can make a difference. 

Keep working at it. I've learned a lot as I go by doing exactly that. Good luck!


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## mark3141 (Dec 22, 2014)

I'm thinking it's somewhere between the mic an PC. Other than whatever is in REW, my set-up has no EQ or tone settings. It runs from my PC to a DAC to pre-amp to amp to speakers. To test my mic, I just pulled up test tones on Youtube. I could hear sounds coming from my speakers up to 17Khz, but the mic couldn't pick up anything after about 14Khz. I'm using a Dayton Audio UMM-6, but I do not have the calibration file. (I threw away the serial number not knowing I would need it to download the file.)

The reason I found the 100Hz dip odd was that, as you can see, it was actually a spike in earlier measurements with my original positions. I'd rather not have to simply live with it since I listen to a lot of acoustic guitar and that range contains a lot of the open strings. Assuming, of course, that the dip is actually audible, can this be fixed with EQ?

But thanks for the advice so far. I'll continue to tweak, measure and see what I get. My first try of moving the listening position back together with a EQ filter has made a big difference so far. At what point do I start to think about treatments and where they'd go?


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## tpointon (Mar 18, 2013)

The more I think about your situation, the more I'm inclined to think that the signal above 10 Khz is not a big issue. I think the important parts are the low frequencies usually sent to a sub, say below 100-200 hz, and from there up to maybe 4-5 Khz where most of the 'music' is. Beyond that are overtones and cymbal sounds etc. These are important, but for more subtle reasons. Only the very young can hear up to 20 Khz. I suggest you set up your sweep from perhaps 20 hz - 2 Khz and measure that. Then tune to make it as linear as possible. 

Bear in mind that our perception of music requires a boost towards the low end, what is called the 'room curve' I believe. See Wayne P's article about this elsewhere here.

You might like to know that I also go all-digital in my system. I have a Raspberry Pi B+ with a HiFiBerry DigiPlus http://www.hifiberry.com/digiplus It feeds my NAD C390DD amp with a digital signal from the internet or my ripped CD's in FLAC on my NAS drive. (The NAD is like a combined DAC and amp) The last addition I've made is a MiniDSP nanoDigi (http://www.minidsp.com/products/minidsp-in-a-box/nanodigi-2x8-b between the Raspberry and the amp. The nanoDigi is an all-digital signal processor that I'm using as a parametric equalizer (5 bands). I got REW to do the equalization and calculate filter values to tune to my room. With my computer connected by USB to the nanoDigi, I entered the calculated filter values. The nanoDigi keeps these settings after disconnecting the computer/USB cable. I like the sound I'm getting through this configuration, and it gives me some extra settings to fine tune in the pursuit of the best sound I can get with my overall resources.


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## willis7469 (Jan 31, 2014)

While I do agree with much of the advice above, I have to disagree about not chasing the 10k roll off. I am 40(old?) and can hear up there without much trouble, and you've indicated you can up to at least 17k. Plenty going on up there (imo). 
I fell asleep reading a nice review of your setup. Have you experimented with different jumper configs? This was an area that wasn't made too clear of the effects. Also the 1/5 thing was in reference to anyplace that lines up. IE, increments of that along the front wall, and into the room that distance. I don't think you're too far off, and it's just a reference(albeit effective). 
I use this app on my phone, and compared to YouTube, it's much more streamlined. (Maybe android too?)Audio Function Generator PRO by Thomas Gruber
https://appsto.re/us/pgCw1.i


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## tonyvdb (Sep 5, 2007)

Just to back up the bus a little. When your running REW and the umm6 your not using any calibration file at all?


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## mark3141 (Dec 22, 2014)

Tony,

That is correct. Is there a way to make up for it? Since I can't get a calibration file, I was using the SPL calibration and assumed this was good enough. I'm still not sure what the issue is, though. I don't think it's the mic itself or my system. I noticed the noise floor would change unpredictably based on the mic level set in Windows. For example, at times, the mic would increase in volume, but the noise floor would drop.

But despite all the fun I had yesterday moving my stuff around, I'm not sure I'm in a better position. While well-recorded, sparse tracks sound great, it's easy to start to feel overwhelmed as the track gets more complex. There are just so many variables; I'm having trouble really knowing where I should be starting. (I did mess with the jumpers but could hear no difference at all.)

Tim,

How do you like the Raspberry Pi? I thought about using one due to the lower power and footprint, but I'm a little nervous. Have you done any A/B testing? To me, my USB input sounds a lot worse than my optical input. Once I feel comfortable using this software, I may formally compare the two and see if it's all in my head or actually there.


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## tonyvdb (Sep 5, 2007)

Without the calibration file loaded your above readings are fairly much useless as REW needs to have that loaded to even know what mic it's using.
Also the waterfall graphs are not very helpful above 400Hz so you will want to adjust the grid layout and the sweep to only 10-400Hz


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## tpointon (Mar 18, 2013)

mark3141 said:


> Tim,
> 
> How do you like the Raspberry Pi? I thought about using one due to the lower power and footprint, but I'm a little nervous. Have you done any A/B testing? To me, my USB input sounds a lot worse than my optical input. Once I feel comfortable using this software, I may formally compare the two and see if it's all in my head or actually there.


I like the Raspberry Pi model B+. By itself it only has analog audio out but when fitted with the HiFiBerry Digi+ I have SPDIF and Toslink digital audio. I'm running RaspBMC on the Pi. It's a distro of Linux with XBMC included. I had some issues following the 'bouncing ball' installation steps but was able to work through with the help of Google. You need a PC to load the Linux image onto a micro SD card from which the Pi boots. I leave the Pi running all the time and it virtually never crashes. I run BubbleUPnP on my Android tablet directing it to use my NAS as library and XBMC as renderer so I can drive from the couch. Another app, xiialive allows me to choose shoutcast 'radio' sources and direct BubbleUPnP to play them through XBMC.
http://www.buyapi.ca/product/raspberry-pi-model-b-plus/ 
http://www.hifiberry.com/digiplus
http://www.raspbmc.com/

I'm not a purist audiophile in that I use Axiom speaker cables and pretty generic signal cables and being 66 years old, I left the analog world behind when the CD arrived. I have purchased a few 24/96 albums which are also part of my library. I do like the sound I'm getting through my Pi/Nad C390DD/Axiom M80s. I've been amazed at how much of an improvement I get when I apply equalization as calculated by REW, and I still think I have a bit of tweaking to do. It's a challenge to work out best positions for sub/mains/listening-position and I have eq setttings on both my amp and the nanoDIGI. Gives a retired computer professional something to keep the grey cells exercised lddude: tp


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## mark3141 (Dec 22, 2014)

I was able to finally find my serial number and get the calibration file for my mic. It seems the original measurements on the low end were pretty off, but the high end roll off is still there (attached). 

I'm still frustrated with louder, higher pitched passages. For example, on Derek and the Dominoes "Bell Bottom Blues", the chorus just sounds bad, especially the guitar passages between the vocal phrases. The verses sound fine, but these passages just get muffled and confused. Anyone have any thoughts on what might cause this, and if I can 'see' this in any of the measurements done by REW? I know frequency response doesn't tell the whole story, but it's the only one I really understand. I'm going through the help files, but it doesn't really tell you what to look for in say, the impulse response.

I originally bought a Raspberry Pi to run XBMC, but I switched to running it on Android from my Amazon Fire TV which allows me to do Live TV, Netflix, etc all from one interface. I haven't seen the HiFiBerry so that might be a good way to avoid using USB out. It would be nice to have it all on one box, but the AFTV resamples all audio. (Honestly, not really sure how much of a difference that makes...yet something else I'd like to compare.) 

I can't find a lot on what the MiniDSP does. If it simply runs filters, it appears you can run that off of a Raspberry Pi. http://volumio.org/forum/dsp-with-raspberry-hifiberry-and-volumio-drc-folve-t672.html

With regards to your set-up, Tim, I don't think your speaker cables and the rest really matter. I'm pretty skeptical of most audiophile gear. I think the only way to really hear a difference in cables would have to be a combination of really exceptional hearing and really exceptional gear. As long as your cables are a decent gauge with a fairly low resistance, it's hard to see how it would matter. This is a pretty good article on it: http://stereos.about.com/od/accesso...ables-Make-A-Difference-Science-Weighs-In.htm


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## tonyvdb (Sep 5, 2007)

Are you sure your tweeters are even functioning? What speakers are you using? Do they have bi amp capabilities, could the jumper be missing between the binding posts?
The drop is farly clear your missing everything above 5k


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## willis7469 (Jan 31, 2014)

http://www.6moons.com/audioreviews/usher3/2.html
Here tony. 
I wondered about tweeter function too.


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## mark3141 (Dec 22, 2014)

I'm using this set-up: http://www.6moons.com/audioreviews/usher3/1.html They're capable of biwiring/biamping, but I'm not doing any of that. The jumpers are set correctly...I have the amp feeding the subs which are then jumped to the bookshelf portion. I did try messing with some of the biwiring by running one lead from the amp to the sub and another to the bookshelf, but the only difference was on the low end. (Same as if I reversed and ran to the bookshelf and jumped to the sub.) 

The tweeters are functioning in that I can hear them and feel them pushing out air. As mentioned earlier, using the signal generator, I can hear 17khz so I'm really not sure what the issue is.


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## mark3141 (Dec 22, 2014)

For what it's worth, it's not the computer. I tried switching to another and had the same result. They both have Realtek audio drivers, but I don't think that's the cause since I see the same results on optical and USB, the latter of which should bypass the soundcard. I also tried a different USB cable to the mic with no luck. Since the mic is the only thing I haven't changed, there has to be some issue there; I just don't know what.

Guess my earlier post didn't show. I tried a different set of receiver and speakers with no change, either, hence why I think it's the mic.


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## robbo266317 (Sep 22, 2008)

I would recommend getting the calibration file for your mic to start with. (As per their documentation http://www.daytonaudio.com/media/resources/390-808-dayton-audio-umm-6-user-manual.pdf)

Calibration:
To deliver the most accurate results, a calibration file must be loaded into the software program being used for audio analysis. This calibration file is generated based on the serial number of your UMM-6. To obtain your calibration file in text format (compatible with most audio analysis software), visit DaytonAudio.com and navigate to the UMM-6 product page. Enter the serial number of your UMM-6, then click on “Download.”
Write your serial number in the blank provided below, in case the printed number becomes scratched or
worn on the microphone body.


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## mark3141 (Dec 22, 2014)

I did... I thought I lost it but was able to find it.


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## chashint (Jan 12, 2011)

This is interesting.
The frequency response plot looks to me like the tweeters are at least partially functional.
The crossover in the speakers would roll the 'woofer' response off well before what you are measuring even if the tweeters were disconnected.
I would try to validate my measurement system.
If there is a set of computer speakers measure them to see if the roll off on the high end is duplicated.
If the roll off is pretty much the same the measurement system has an issue.


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## mark3141 (Dec 22, 2014)

I ran a test with my optical out directly to a receiver and different set of speakers and got this. It leads me to believe it's not the speakers, amp or preamp. I also tried using different software to make the recording with no change.


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## chashint (Jan 12, 2011)

Per the spec sheet.
S-520 GL
Sensitivity 86 dB @ 1 watt / 1m
Nominal impedance 8 ohms
Frequency response (-3 dB) 52 Hz ~ 20 kHz
Power handling 75 watts
Crossover frequencies 2 kHz

To bad the review article has no objective data to look at.


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## mark3141 (Dec 22, 2014)

Does this help?
http://www.stereophile.com/content/usher-audio-technology-s-520-loudspeaker-measurements


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## chashint (Jan 12, 2011)

I cannot help with the REW. Sorry.
It looks like there is something wrong with the measurement system though.
Since you cannot hear the last couple seconds of the REW frequency sweep that indicates it is on the computer output vs the mic input, but I do not know how long each frequency is held or the step size between frequencies.
Maybe Wayne will see this and impart some wisdom.


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## chashint (Jan 12, 2011)

mark3141 said:


> Does this help?
> http://www.stereophile.com/content/usher-audio-technology-s-520-loudspeaker-measurements


Certainly looks like those speakers are real world capable of 20kHz output.
I know calibration/room characterization can be frustrating (that's why I have never downloaded REW, some things are best unknown).
Good luck to you.


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## robbo266317 (Sep 22, 2008)

I have done a quick overlay of your first graph and the one supplied in the review. ( I know they aren't lined up exactly, but as I said it was quick :bigsmile: )
Here is the result.


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## mark3141 (Dec 22, 2014)

Interesting and nice catch...I see they have a spike before the high frequency drop, but I have a drop. Is that likely due to my room/positioning? It looks like you took that from my first measurement, and I've moved them around a bit since then.


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## robbo266317 (Sep 22, 2008)

Yes, that was the first measurement and the review said they measured the speakers at 50" (1.7m) on the tweeter axis in an anechoic chamber.

You could do either a close mic reading of the tweeter or a gated measurement to see what it's response is without any room interaction.


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## tpointon (Mar 18, 2013)

mark3141 said:


> I can't find a lot on what the MiniDSP does.  If it simply runs filters, it appears you can run that off of a Raspberry Pi. http://volumio.org/forum/dsp-with-raspberry-hifiberry-and-volumio-drc-folve-t672.html



I downloaded the latest Volumio image but it won't boot on my Pi model B+. See http://volumio.org/volumio-raspberry-pi-b-plus/ The links you've provided are interesting and I will pursue. 

The nanoDIGI is capable of more than I am asking of it. I think it can be used as a crossover as well: it takes 2 inputs (L+R) in either coax or fiber and mixes/crosses them to 4 outputs (L+R each). I think it is roughly the all-digital equivalent of http://www.minidsp.com/products/minidsp-in-a-box/minidsp-2x4 for which there is more info online. The nanoDIGI is pretty new methinks.

Since my sources are all digital and my amp has only digital inputs, I wanted a DSP for equalization that would not require a DAC->(analog)DSP->ADC configuration. The nanoDIGI was the only candidate I could find where price was not prohibitive. When filter application matures a bit on the Pi B+, I will likely prefer that as long as the Pi can handle the processing load. 

Cheers, Tim


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## mark3141 (Dec 22, 2014)

Thanks, everyone, for their input. I did the nearfield measurements and believe it's a combination of the room and one speaker. As you can see, one speaker looks pretty good in this measurement, but it exhibits a roll-off when taken from the listening position. However, the other has a pronounced drop even in the nearfield. I recently moved and noticed the mesh over the tweeter was indented and thought I would push it out. When I removed the tweeter and did that, though, I must have done something else to further damage the speaker as you can see here. I'm not much of a DIY'er, although I'd like to, so I'll tinker a little before taking it somewhere.


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## robbo266317 (Sep 22, 2008)

That nearfield looks a lot better, now let's hope you can get the other channel working properly.


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## robbo266317 (Sep 22, 2008)

Have you had a chance to have another look at your faulty tweeter?


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## mark3141 (Dec 22, 2014)

I did, but I haven't had much time to mess with it. As you can see from the pics here, the tin(?) piece on the voice coil is in pretty bad shape. It looks like it was crushed at some point. After pulling it out this time, I tried smoothing out the little tin piece which improved things a little. 

I'm guessing there's no way I can just replace that metal piece and will have to replace the whole tweeter (and therefore both tweeters). Any recommendations among the tweeters from the link you sent earlier? I'm not sure what I need.


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## robbo266317 (Sep 22, 2008)

I think the link I sent is the "upgraded" spec substitute, I will be back home tomorrow or the day after and can check if you wish. (currently visiting mum and my sister up the coast  )
Hope you had a good Christmas and New Year. :TT


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## mark3141 (Dec 22, 2014)

I'd appreciate it. I've also emailed an Usher distributor in the US to see if he can get a voice coil, but at the moment, he only has the full tweeters but for far more.

Enjoy your visit and thanks for all the help.


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