Sunday, November 27, 2011

How to Sellect and Place Surround Sound Speakers

Background:
Audio was my passion before I started working in the computer industry. I had taken some studio recording classes, did PA for a lousy rock band, and sold TVs and stereos.  I then got my FCC first class license while in electronic school. In 1976 my audio system cost nearly $2000 and it sounded ausome. This was 1976 dollars. It makes me sick thinking about how much that would be in today’s dollars. Lucky for us technology is a lot cheaper today.

Below I will show you what you need to know to get a good value 5.1 speaker system for around $650. Yes, this will not be a studio quality system but it will be a lot better than if you just picked up almost any of the theater in a box systems. Our ultimate goal is to configure an entire surround sound system for ~$1000. You can apply this knowledge to higher or lower end systems as well. It all scales.

Summary:
    1) Don’t pay list price for speakers. 30% discount is the minimum you should expect.
    2) Speakers are the most important components of a surround sound system.
    3) L, Center, & R are the most important speakers.
4) Don’t buy speakers unless you can listen to them. If you can, bring your own music to demo the speakers with.
5) Don’t get fooled when comparing speakers. Listen to them flat. Louder is not necessarily better.
6) Make sure the speaker’s power rating is greater than your receivers power output(RMS into 8 ohms). Ignore dynamic output power.  
7) Don’t get ripped off for speaker wire. 16 or 18 gauge lamp cord wire works fine.
8) Stay in phase. Connect +’s to +s, Red’s to Red’, -’s to -’s. and Black’s to Black’s.

As people replaced there standard TVs with HDTVs, they do not have to accept the less than HD sound that their slim TVs provide. Modern TVs have sound not much better than a laptop. In this post I will cover basic components of a standard surround sound system and the basic things you need to look and listen for. I will also give advice on placement and shopping suggestions.

Parameters
I will define a surround sound system comprising of a receiver and either 5.1 or 7.1 speakers. The ".1" refers to the number of sub-woofers. To keep things real, lets assume our budget is ~$1000. You can spend less and you can spend a lot more. I have seen some good  configurations for $600.

Speakers are the thing you listen to but most people are entranced by the lights, features, and power of the receiver. If you have $100 to put towards better speakers or a better receiver, in most cases you will realize better sound if you put that extra $100 towards better speakers.

Because speakers carry the highest profit margin on any component of a surround system, besides cables, you should realize the greatest discounts. I expect to get around 30% off list price. 50% is not unusual. Some less common professional series speakers may not have such high discounts but you can always ask.

Listen:
When shopping for speakers, the first thing you must do is listen to them. Listening is the best way to determine if a speaker system is right for you. Some times it boils down to a personal preference. When you go shopping for speakers bring a couple of recordings of they types of music you like to listen to. You want music with a good range of sounds, like percussion, brass, strings, and vocals. Ask the salesperson to put the music on and have them switch between the speakers you are are considering. Also ask them to play through their best speakers so you can hear what the “if money was not an issue” would sound like.

Things to listen for are, clear and sharp highs. Do the cymbals sound like they should or do they sound like someone through a towel on them? Do the vocal sound like the singer is standing in front of you or do they sound like they are standing outside the room? Do the drums have a good thump or do they sound like someone hitting the bottom of a trashcan?

Don’t let your ears trick you. You will perceive louder sound as sounding better. Speakers have different sensitivities. In the specs this is documented as the number of db with 1 watt of power at 1 meter. The higher the number the louder, more efficient, a speaker is. Just because it is louder, does not mean it sounds better than another speaker. You will need to consciously try to compensate for the difference in efficiency. Another way your ears can trick you is perceiving more bass is better, especially at low volumes. This is what “Loudness” button does on some receivers. When the sales person is demonstrating the speakers, ask him to make sure he/she has the receiver set to “flat”, no bass or treble boost. If you want more bass when you bring the speakers home, you can always add it by the receiver settings or speaker placement. When listening to speakers, if a speaker is on the floor or in a corner, you will hear more bass. I don’t want tp go into the physics of why this happens but believe me it is true.
  
Specs:
What about specs? All good quality audio components have specs that are published by the manufacturer. Understand, specs that are not compulsory, manufacturers may not publish all specs. They also have a tendency to try to add confusion by publishing similar sounding specs but are derived on some non-standard scale. The specs you are looking for when it comes to speakers is, power rating, resistance (ohms), efficiency(DB with 1 watt at 1 meter), and accuracy (+ or - DB from 20 to 20K Hz). If the manufacturer does not publish these specs, look for reviews online where they derive these measurements during testing.

The power rating is the min and max power that should be supplied by your amp/receiver. The min is the least power you receiver should be able to produce to create a decent sound level in a normal room. The max power is the max power you amp/receiver should be able to produce “cleanly” into 8 ohms without damaging the speaker. Actually you can fry a speaker with significantly less power if the power is not clean. If you overdrive you amp it will do what is called clipping. Basically the signal is a sine wave. If the amp is just a multiplier. If the input source x the multiplier of the amp is greater than the max output of the amp, the tops of the sine waves will be flat at the max power level. This flat level is DC current. Speakers do not like DC current because the speakers become a short and get very hot and warp the coils in the driver. Don’t want to bore you with electrical theory but believe me, if you crank up your system so loud it distorts, it will eventually fry you speakers. Back it down.

Resistance is futile but necessary. Speakers usually have a resistance of 8 ohms. Anything less can cause you to blow a breaker on you receiver or fry it totally. Usually only very high end receivers can drive loads of less than 8 ohms. To be safe, only deal with speakers with resistance of 8 ohms.

Sensitivity we discussed above. If your receiver is lacking for power or you have a large room to fill with sound you may care about this. In most households this is not a driving factor, unless you really like pissing off your neighbors or your wife fills the room with heavy drapes, thick carpeting, and overstuffed furniture. Soft things suck sound out of the air. BTW- people are soft. I usually only use this number to help be compensate for volume differences when comparing speakers.

Accuracy is how accurate a speaker reproduces an input signal across the hearing spectrum, 20 to 20K Hz. This is measured in + or - db. The lower the number the better. Basically if the number for a speaker is + or - 3db from 20 to 20K Hz, it means each frequency  inputted at the same power level, the resulting volume will not differ by more than 3db. If a speaker manufacture lists a range larger than 20 to 20K, it is useless unless you are a dog or a humpback whale. For sub-woofers, they will most likely have a range from 20 Hz to something a lot less than 20K Hz. This is acceptable since sub-woofers only need to reproduce low end sounds. The same thing applies to satellite speakers but at the other end of the spectrum. You do want to make sure the ranges from the sub-woofer and the satellite speakers do have some overlap or you may have a hole in the spectrum your system can reproduce.

Because of the physics of sound, size does matter. Usually the larger the speaker enclosure the richer sound on the low-end range. This is because of the natural resonance of the cabinet. Also. speakers should be heavy. This improves the cabinet's resonances and assures it does not dance around the room at loud volumes.

When all else fails, search for professional reviews. Take customer reviews with a grain of salt. Look at sights the specialize in audio hardware reviews, not Consumer Reports or Better Homes and Gardens. A place like Audio World is a good place to start. Always try to find multiple reviews. Speakers can be a “personal preference” type of decision, so assume any author has their biases.

Speaker Priority:
When selecting for 5.1 or 7.1 system speakers, some of the speakers are more important than others. This is an issue I have with many pre-configured speaker packages. Usually they use the same speakers for the rear satellites as for the front speakers. If manufacturers would put better speakers up front and maybe some less expensive speakers for the surround satellites, the total sound would be much better for the same cost.   

The 3 most important speakers in a 5.1 or 7.1 system are the front right, left, and center speakers. These define the sound stage by helping to create for the listener the placement of instruments and sound effects. Put on Dark Side of the Moon and you will know what I mean. The center channel speaker provides vocals in videos and may provide some center placement of instruments in music. Most music is recorded in stereo so what is sent to the center channel is determined by the receiver and its surround sound settings. These three speakers, L, R, and Center provide most of the sound so they are the most critical to your listening enjoyment. My personal opinion is put at least ½ of your speaker budget into these three speakers.

The next most important speaker after the front 3 is the sub-woofer. This single speaker provides the low end sounds, base drums, rumbling of thunder, etc... The reason you only need one of these and its placement is not that critical is because the low frequency wave lengths are longer than the distance between your ears so you can not perceive direction of the low frequency sounds. I will assume you will only be considering powered sub-woofers. There are only a couple of things to look at, first the speaker diameter. The larger the diameter, usually the lower the frequencies that are reproduced. The next thing is power of it’s amplifier. The more watts, usually the louder it can go and the more easily it can drive the lower frequencies. When the sub tries to produce really low frequencies the signal approaches DC and this causes speaker driver to suck power. This is why a 100W to 300W sub is not unreasonable. The next thing is Signal to Noise Ratio. This is how much unwanted noise (hum and hiss) as compared to the wanted signal is produced by the electronics of the sub. The higher the number the better.

Sub-woofer connections can differ. I like to have a single sub-woofer connection directly from the receiver to the sub. Most receivers today have a sub-out output. With this, the receiver can provide a low power signal to the sub. Usually the receiver will have an adjustable crossover setting allowing you to determine what frequencies go to the sub only. It is not unusual for the sub to also have a crossover filter adjustment. A crossover is the filter that cuts out the frequencies the speaker can’t handle and only allows the frequencies to pass that it can reproduce. The last thing you want is for the sub to be sent signals for bells or your satellite speakers to get the signal for a bass drum.

The last speakers in the speaker hierarchy are the 4(7.1) or 2(5.1) satellite speakers. These speakers provide 3D spacial placement of sound in the room. Is 7.1 better than 5.1? It depends. Do you have a place to properly place the extra 2 speakers in a 7.1 system. In my house, I would have to put one in the fireplace and the other right over a couch. If you have the place to put these properly, go for it. But if you can put extra $’s into the front speaker by eliminating 2 satellite speakers, stick with a 5.1 setup. Also HDTV signals and DVD’s only provide 5.1 sound. Blue-ray and some pay-per view satellite shows on DirecTV have 7.1 sound. 5.1 works fine for my needs and I don’t get any complaints from my wife about how the system looks.

Since the satellite speakers only provide placement and the most important sound comes from the front speakers, you can get a way with less expensive speakers for the rears. You don’t want to go to cheap. I would say a reasonable rule of thumb would be, the rear satellites should cost no less than 1/4 and no more than ¾ of what your front R & L speakers cost. I would lean towards less than ½ of the cost of the front L & R speakers.

Example 5.1 Configuration:
For example, lets say you have $650 to spend on your speakers. Expect to spend $350 on the  3 front speakers, $200 for the sub and $100 for the two rear speakers.
An example configuration from Newegg.com 11/26/12
    Polk Audio Monitor40 Series II $149 a pair
    Polk Audio CS2 Series II Center Channel - $149
    Polk Audio PSW Series PSW505 Subwoofer- $229
    Polk Audio Monitor30 Series II - $79 - Regularly $120.
Total - $606

If this is to much trouble Polk has a pre-packaged speaker system for $399, the Polk Audio RM510. While my configuration is significantly better, the pre-package system will sound a lot better than your TV speakers. You get what you pay for. Will my configuration sound 50% better? I think so.

It is not required that all the speakers come from the same manufacturer. My home speakers are a mix of Polk and Harmen Karden speakers.  The nice thing about Polks is you can usually find them at Best Buys and listen to them, then buy them cheaper on-line. Speakers will sound better at home than they will in the store because you can better place them and you will have better acoustics.

There are a number of good speaker lines that are available in the price range we have been discussing. Boston Acoustics, JBL’s consumer line, Infinity, Advent, and others make respectable speakers. Yes, Bose does make lower end speakers but I think you can do better with more traditional designs at this price point.  

Speaker Placement:
Now that you have bought your speakers, where do you put them? The front L & R speakers should not be placed more than 12ft apart. Any more distance between them, you have a very good chance of having a very indistinguishable sound stage. You will not easily tell where the instruments or sound it suppose to be in front of you. 6ft is good distance. In my system at home, I have them on either side of my 46” TV, since they mostly serve as my TV speakers. If I wanted to put them 6ft apart, I would have to hang them off my windows. You will probably have to make some trad-offs when it comes to speaker placement. For a home theater system, you really want the speakers an equal distance on ether side of the TV with the TV in the middle. The center channel speaker goes directly over or under the TV. Don’t put it on the floor or near the ceiling. The sub-woofer can go just about anywhere. Don’t put it in a corner or behind furniture. The corner will make it sound even boomier and if you put it behind furniture the sound will be blocked. The rear channel speakers should be slightly behind the listener to fully behind. The satellites should  be at ear level or slightly above. These are optimal placement suggestions but we all live in the real world and our houses or spouses may not accommodate “optimal”. Just do the best you can.

If your room is a rectangle, have the front speakers at a narrow end of the room. This way you will better take advantage of the acoustics/resonance of the room. This is not always possible and most people will not notice the difference.






Speaker Wiring:
When wiring your speakers, you don’t need to get monster speaker wire. I use 16 gauge lamp cord wire. Just don’t have to much extra wire. Having an extra foot or two is OK, but don’t have an extra 5ft looped somewhere, unless you want to also hear the local AM radio station or your neighbor’s CB radio.
The most important thing to be aware of when connecting your speakers, do not mix up polarities of your speaker connections. All speakers and receivers have a “+” or “-” terminals. They may be color coded as Red and Black. Don’t mix these up or your great sound system will sound like crap. This is the most common mistake people make. Each wire pair has either a silver side and a copper color side or a smooth casing side and a ribbed casing side. Keep these straight. Put all the copper colored or ribbed wires to the red terminals and the other wire to the black. It really doesn’t matter which as long as you are consistent with all the speakers.  If you do mix them up, one or more of your speakers will be 180 degrees out of phase. Basically one speaker will be pushing out and the other one will be pulling in and they will cancel each other out. This makes the sound seem muddy and you will not be able to visualize the sound stage because the sound placement will be messed up.

Safety:
        Don't run wires under carpet or in traffic areas. Worn wires can short and fry your amp if your lucky or burn you house down if you are unlucky. Also you need to avoid trip hazards. Several places sell wireless devices that will allow you to run your rear speakers wirelessly. Rockfish is the brand sold at Best Buy. They have a Universal Wireless Rear Speaker kit for $109. 
Sorry about how long this post was but I tried to condense it as much as I could without getting too technical. My next post will cover selecting the right receiver.

Sunday, November 20, 2011

My first impressions of my Android tablet


My first exposure to Android:
I got my Toshiba Thrive 5 days ago and here are my first impressions. This is my first real exposure to Andriod. 
Summary:
1)      If I needed to replace my PC, could I replace it with a tablet?- NO
a.       I need to run my tax program
b.      I need to edit and read .docx files
c.       I need a real keyboard to be productive (yes I can get a Bluetooth keyboard but then I would just have a laptop.)
2)      Would I buy an iPad or an Android tablet? – Android
a.       I don’t like the restrictive nature of the iTunes/iPhone echo system. Some people are happy with iTunes/iPhone’s restrictions, I am not.
3)      If I had only $400 to spend and I had to either get a laptop or a tablet I would get the laptop. If I
had only $1000 to spend, I would get a better laptop, a smartphone, go out to a nice restaurant, and 
maybe a Kindle Fire.
Background:
For the last year and a half, I have been using an iPhone 4 which is my first and only exposure to Apples iOS. I like my iPhone but I am always frustrated by the restrictive nature of the platform. When looking for a tablet, I wanted to try something different and hopefully more open. Since I have been involved in Linux development for the last 12 years, Android devices seem to be a natural fit. Costing less than an iPad2 was an added bonus.
My main use for a tablet is to learn app development, e-mail, web browsing, and the occasional game.
I shopped around for a while and determined my minimal requirements.
1)      Android 3.1 or higher
2)      Duel core Integra 2
3)      16GB of storage
4)      1GB of memory
5)      7” screen or larger
If money was not at issue my first choice was an Asus Transformer Prime with better graphics, 10” screen, and a 4 core Integra3, but I would then be hitting the iPad2 price point. Instead I was able to get a Toshiba Thrive 16GB 10” tablet for almost half the price. Yes, it is thick and heavy but I got it for a good price and it will serve my needs. This is important; determine what you need to do and your budget.

What I like about iOS(iPhone/iPad):
It works. If you don’t mind staying within the boundaries defined by the iOS platform, it is a great platform. It is well integrated into the iOS/iTunes echo system. It is easy to use and it is very stable.  

What I like about Android:
1)      You can add extra storage - Unlike iOS devices, every Android device I have seen has an SD or micro-SD slot for additional storage. If you buy a 16GB Apple device, that is all you have. The only remedy is to buy another expensive device for more storage. Most of, if not all, the Android tablets can handle up to 32GB SD or micro SD cards. You cannot install apps onto the SD cards but you can install data files, like MP3 files, movies, etc…. I have 16GB of music which I can put on my SD card and leave my main 16GB free for apps and other stuff.
2)      Integration with Google-Yes Google is a big brother corporation like Apple but Google allows me to do more of the things I want to do. My GMAIL. Google Docs, and my Calendar are all seamlessly synced between my Android tablet device and the Google cloud. If I don’t have my tablet with me, no problem. I can get on any device with an internet connection and a browser and get access to all my stuff. I don’t need to back things up because they are on the cloud and Google does it for me. The downfall is, Googledocs does not do you much good if you don’t have access to a WIFI connection to the Internet. There is no local copy of Googledoc files on the device.
3)      You can print some things – From Googledocs you can print to your windows PC if you do the setup through the Chrome browser. Yes, you need to have your PC powered up but you don’t need to buy one of the very few printers that support Apple iOS. I can print to any printer that is connected to my PC. Actually my printer is a network printer that my PC uses. Google does have a few Cloud Printers which do not need a PC as a proxy. The Cloud Printers just need to be connected to your network. This is similar to what Apple has. The one thing nice about Google’s solution is, it allows me to use the printers I already have.
You cannot print everything, such as screenshots or from the browser on the tablet. While print options are better than Apple they are not complete.
4)      You don’t need iTunes or email files to your device to copy them – When I plug in my Android tablet into the USB port of my computer, it mounts as if it is a USB flash drive. I can simply copy, edit, and delete file just like a flash drive. If I want to put a PDF document on my tablet all I need to do is drag and drop. The only way I found to do this easily on my iPhone is to mail it to myself. I then had to leave it in my e-mail.
5)      I like the Android desktop – The Android desktop just looks cooler. I like the widgets. The iOS desktop seems so regimented compared to Android.
6)      It is running Linux – Having worked on Linux for the last 12 years I am prejudice, but is a rock solid OS. You don’t need to know Linux because it is buried underneath the Andriod UI like most things using Linux, like your home router, DVR, cable set top box, and the ATM machine down the street.  

What about Android I don’t care for:
1)      It sometimes does not work – The one thing I like about iOS, is that everything works for me 99% of the time while Android seems to work 97% of the time. The Android OS is fine, it seems the applications have issues. I crash the browser at least once a day. The OS always seemed stable. It appears to be an issue with the apps or maybe Java. I am not sure the cause, I am only sure of the results.
2)      Things are different from iOS – This is more of a “what you are familiar with” issue than a functional issue. I am just use to where things are in iOS. Everything in Adroid is there; I just need to learn where they are.
3)      Security – Because of Apples restrictive app store, you are less likely to download a mischievous app. The Android marketplace can be like the Wild West. You need to know what you are downloading. Practice safe downloading.
4)      No Screen Capture – This is dumb simple on an iPhone. On Adroid, you need to get the SDK and connect to a PC. Maybe when I start playing with the development tools, this will not be an issue but for the average user, it is not practical.
5)      No iTunes support – This is not an issue for me. I have all my music on CD’s. Yes, I like the physical media. When you are my age you can find a lot of music you like in the discount section of Best Buys or WalMart. I have around 150 CD ripped to MP3 format.  If you have all your music in iTunes format, you are probably out of luck. It will only play on Apple devices or in iTunes. There is a restriction free format for iTunes. If you music is in this format, you should be able to convert it to mp3’s. As I stated earlier, not an issue for me.

Saturday, November 19, 2011

What's next

Here is a list of things I plan to post in the next couple of months.

  1. My first impresions of Android on my tablet.
  2. Tech we should have at home but don't.
  3. The wonders of Googledocs, why I love this tool.
  4. Suround sound systems.
My posts will attempt to be some what technical without overloading on details. I will try to explain why some things  are useful to me and other things are not.

This blog will be my opinions about technology. I will keep religion, politics, and pictures of my pets out of here. That is what Facebook is for.

Friday, November 18, 2011

The beginning

This is my first attempt at blogging. Lets see how it goes. I plan on using this bog to give my thought and insights to some of the new, old, and current technologies people and businesses need to deal with on a daily basis.