Thursday, June 6, 2013

"POWER", The Myths and Maths Series Part 2

LET'S GET WIRED!  OFC vs CCA

There's been some unsolicited promotion lately by, 'independent', reviewers about the benefits of OFC over CCA wire.  The fact is that both are fine, it comes down to the capability of the wire and the application, (How you're going to use the wire).

This applies both to it's use as speaker wire and power wire... And to throw a wrench into the machine, manufacturers are developing a new type of wire that has the heft of OFC but the capacity of CCA and costs half that of CCA.  Last time I heard, it was the addition of tin, so now your wire will rust instead of just turning green.

First off, let me debunk the 'testing' that's been going on in some of these videos.  Several videos have the wire in coil, which makes for a big inductor.. Never a good idea to test wire this way. This is also not how wire is used when in the car or boat.

First, I would use a standard length that's in a kit, say 16'.  Second, identify both the wire's material and it's diameter.  After that you can actually use a chart to determine what can be used before it affects both performance and your ability to inhale large amounts of toxic smoke.

Don't worry about what is, 'spec', or what GA vs AWG mean.  Look at the material, diameter and length.  (By the way, in the wire industry there are three standards, China wire, Taiwan wire and American wire gauge. That addresses why one brand will say, 4ga and another will say 4ga but the actual wire diameter will be different.  It has nothing to do with 'quality'.  It has to do with different standards.)

Second you have to look at how the wire is applied.  Most standardized tests done are for an 'open air' test, meaning the wire is suspended in the air so that it can be cooled by methods of convection.  Then on top of that, you have to calculate what the ambient air temperature affects it.  Even more calculation if the air is moving, how fast it's moving, is it recirculating or is is coming in from a fresh source.. Just like when you want to cool your amp with a fan.

But enough of all that, most of the applications used in car or boat audio are fine with CCA.  All wire just has an ampacity.  A capability to transfer current.  For mobile audio, this is not constant power.  It's pulsed which makes a big difference.  On top of that, you'll see on many charts what the resistance of a certain gauge wire is at 1000'!  That's a big difference than the 16' to 25' that you're using.  These charts are up over 100A you can see no difference.  Take into account that speaker wire is nowhere near that type of power and is it really that important to have 10 AWG OFC?  No.

The big push of OFC is in the profit margin vs CCA.  The total volume and especially the margins of mobile audio have eroded significantly in the past 20 years.  It's no wonder brands would pay to stage an 'independent test'.  There's a good chunk of cash on the line, even after all the erosion.

In the world of audio, they can even get away with paying people with just product for good reviews instead of the usual chubby envelope given to more 'reputable' sources like magazines.  Do you really think people buy $10,000 cables?

Ok, ok... An example of power application.  Let's take the standard Taiwan spec 8ga CCA used by Metra in their Raptor line, (Just changed to 'full spec' this year).  Not getting hot enough to melt the fuse, you can still use this with a crappy, standard AGU glass 60A fuse.  This is plenty for most systems.  It may even be cheaper and have a lower profile to use multiple strands of 8ga CCA.  Of course each strand is good for up to 60A.

For 4ga CCA from Raptor, we go up to 100A AGU fuse.  Anything beyond that would require 2 or 0ga CCA or multiple runs.  Also, I recommend to many clients that get the OFC bug, to just add another run of wire rather than pull out the 'bad' CCA and go all copper.  The industry is again employing the snob tactic that you want to be superior over others.  This of course only costs you more money, that those, "poor", or "crappy", type of people won't pay.  I never agree with these tactics as they create small wars of "us vs them".  Apple is famous for using this marketing strategy.  In the end however, everyone of the unwashed masses remembers the way snobby people act and they always get taken down a notch or just taken out by an angry, poor mob.

As for OFC, if you can get a good price on it, use it.  It's not any better than CCA, it just has a greater ampacity than CCA when compared with all other things being equal.  Most of the time people never even get close to the ampacity of what the wire can do.  Now if you're competing and want to do hair tricks, that's a completely different story.  Just because they use it on a $150k demo car, does not mean that you need it for your the single 10" sub you have in your '87 Crown Vic that your grandma left you.  Use common sense, use Craigslist and always get more information than you need.

Remember that when you buy retail, from a store, you're paying for that store.  Nothing good or bad about that.  Just remember that you're paying for the store plus product, plus mark-up.

I'll take on some amp myths next in Part 3.

Patrick Chandler
Co-Founder of Robot Underground

robotunderground@yahoo.com 


Friday, April 5, 2013

"POWER", The Myths and Maths Series Part 1

Let's Talk About Power! (Part 1)

    I get asked a bunch of power related questions all the time.  My goal in this series is to educate and demystify what manufacturer's power ratings mean and how to apply them in real world situations.  I will also be doing an FAQ section with references and notes when available.  You may not like the answers but when applied, these answers may be the best thing you can do.

    Let us start with part of the chain that users see most. Woofers.  Woofers come in all shapes and sizes and in all cases, the power handling numbers printed on them by the manufacturer are WRONG.  The intent of this number is another story.  Some makers are conservative, some are just liars.  Either way, any number they give you is wrong.

    The reason they're wrong is that are so many more factors in the power rating of a driver that need to be considered.  In the case of woofers, there is program, (signal, music, sine waves, etc.).  Another factor to consider is enclosure size and that relates to the overall question, "What's your application?".  How are you going to use this tool, this device that turns electricity into sound.  I myself have used a wrench to pound in a nail so keep an open mind when it comes to application.  Everyone wants to do different things and it's important to keep that in mind when helping someone or planning your own projects.  Not everyone has the same kind of budget nor standards.  Let's keep it fun and interesting though and explore several avenues of application.


    Entry Level / Woofers

    Entry level subs are by far the best money makers for audio brands / manufacturers.  They cost close to nothing to build and ship, yet the margin on these items is the greatest, (percentage), and the price point is the broadest and most accessible in the market.  In recent years, you may have noticed a flood of these products.  JL Audio for example out did themselves.  The typical 4 tier marketing strategy was W1, W3, W6 and W7 to top it off.  Now they have two more levels of performance below what used to be the entry level woofer, the W1!  That's dookie-load of sku's!  The great part about this is that now everyone can afford to buy a genuine JL Audio woofer.  What's even better is that the WX series is no slouch.  It's certainly not a W7 by any stretch of the imagination but they do get down and work great in small / medium sealed boxes which also save the end user money.  Enclosures can be almost made of cardboard and still sound great due to the low pressure.  Less packing material is required to ship and amp costs / requirements are cut down considerably.  All in all a great deal... Unless you want to do hair tricks....

    Now, back to the problem of POWER.  Assuming what I've seen, tested and heard is true, these two woofers both come from the same factory overseas and are, in essence the same woofer.  Assuming all of that, HiFonics claims this sub is good for 800w Maxx.  (Yes that's double X's because it's that bad-ass!)  JL is much more conservative in their power rating and even make a recommendation.  Their site also has a much cooler graph to show you where the , "DumDum Line", has been drawn at no more than 200w.  With that said, neither of these ratings do anything to address application.  Both of them are wrong and yet, 'acceptable' and legal answers to what these subs can take. (Also don't worry about the secret of the HF series subs getting out.  People that buy the HF series are not the kind of customers JL wants.  (More on that later in the buying / selling blog entry.)



OUCH!  That's HOT!

    So what's a girl to do?  Michael Q. aka Q-Daddy, one of my early mentors broke it down this way.  Imagine a 100w standard work light.  They're really bright, hot and dangerous.  Imagine holding that bare bulb in your hands.  THAT'S what 100wrms feels like!  So if that's what 100w is, how can a speaker company rate a speaker do be double that and not be called a liar?  Simple.  Different makers use different methods of ratings.  Some companies rate their speakers as a "Thermal", rating.  Meaning when they fail or catch on fire, e.g. old Orion XTR woofers.  Some use some very good math and measurements but those numbers still don't address frequency or enclosure size.  None of them ever address the amount of RUN TIME that the driver can deal with that kind of heat.  All of a sudden, 400w becomes an oven in a space the size of your fist.  How long can your woofer deliver awesomeness?  Is that sine wave?  Is it random pink noise?  Is that for an 'optimal' enclosure size?  What is optimal about the enclosure?  Is it for SPL or SQ?  Is it to get the most low end?  What's considered low end?  20Hz?  30Hz? 40Hz?  With a filter or without? Xmax vs Xmech?  110 or 220 VAC?

   Dan Wiggins went through this with his clients when he started Adire Audio.  Here's a paper that shows how the Brahma did with all that power.   After reading the paper, you'll see that enclosure size has everything to do with power handling numbers.  As always, there is a compromise.  You can have great output at 30Hz, but you can't throw 1600wrms at it and expect it to survive... At least not that driver.  Now if you have an Adire Parthenon, that's a different story.

    Can you rebuild a speaker to handle more power?  Yes, but you loose the ability to play deep.  You simply re-build the speaker with higher power handling features like direct connect leads, stiffer suspension, maybe even a lighter cone.  So now your rubber band / woofer is much beefier and tighter.  Can you abuse it more? Yes.  Does it handle six gazillion watts? Yes, but now because of the stiffer suspension it has trouble with the low end which is sorta the whole point to having a woofer in the first place.  To get around this, you can add mass to the driver, you can even put it in a bigger box but you're still limited by excursion to get the loudness at the depth you're looking for.  And now you've killed the sensitivity of the driver by adding mass to it.  There are several ways to get around these problems.  A great example of this is also from JL Audio.  The W7 series.

    Displacement = Bore x Excursion, this is the key to moving lots of air.  Since not everyone can have a 50" sub-woofer in their car, excursion will have to be your friend if you want to make really low sounds quite loud.  The W7 series from JL Audio does a great job of this.  They start out with a healthy amount of magnetic material, the motor as it's called.  Add a tight gap and a soft, as well as large suspension and you've got a winner.  Click the link above and then click on the Specifications tab.  You'll see their cool power graph on what's acceptable.  (More on how JL and other brands cheat at this later.)

    OK, so when you look at these graphs, that's the power that's applied, not the amplifier size.  I get asked all the time, "What size amp do I need?", that's a whole other blog entry I'll make about selling / buying.  Basically, whatever you can afford is the bottom line and then you can deal with that. Since you can afford what you can afford, that's what you go with.  So then the question becomes, "Should I buy a popular brand like JL or Kicker or will a generic China made amp do the same job?"

Check back in a few days, bookmark the page or subscribe to this blog and / or our YouTube channel.

The new video will show you how to make the Mojo / LVS woofer more reasonable or just re-cone it.

Thanks as always,
Patrick Chandler
Co-Founder of Robot Underground

Friday, March 1, 2013

Baffle Step Compensation / Does the shape or size of the baffle affect my sound?

    I was recently asked about something called Baffle Step Compensation Then followed up with the next question does the shape of the enclosure affect the sound?

    If you click the link, you'll learn a bit about BSC.  What the article doesn't really get into is how many makers compensate for it and where it's applied.  Yes the outside baffle, (not enclosure), but baffle shape can affect sound.
    Note the frequencies that it affects which are in the upper range.  You can sometimes see this in high end speakers when foam is placed around the mids and tweeters to dampen them and allow the sound to be more pinpoint.  I found SALK to have a better explanation of BSC.  This is why it's key to have your highs pointed at your head.  The the high frequency sounds are highly directional.  This is why many tweeter makers will apply a lens to help disperse the sound.  A horn loaded tweeter can do even more but you compromise the size and place you can place such an object.

    To eliminate this, some makers will remove the baffle entirely like this popular B&W speaker. Notice that they even used truncated frames and large beveled edges on the sides of the woofers.  In this setup, the woofers may be crossed over as high as 350Hz which would still make them subject to some of the BSC rules, (depending on baffle size of course).  Some makers will surround the tweeter and mid-range area with felt or foam.  On many of the speakers the treatments would be removable so you could play with your options as many audiophiles like to do.  An L-Pad in the crossover would do the same thing as well.  Then again, music is subjective.  You may enjoy the added brightness by the effect.

    BSC doesn't affect lower frequencies like that of subwoofers.  The wavelengths are just so much larger that it doesn't matter.  Which leads to the next question, does ENCLOSURE shape affect sound.  The short answer is NO, only the volume matters for subwoofers that is.  as for a speaker or satellite that plays in the upper frequencies, it can have great effect. Heat and cold have an even greater affect on your system. More on that next week from SpeakerBuilder Magazine.

Co-Founder of Robot Underground
Patrick Chandler


Sunday, February 3, 2013

Super Bowl Specials ALL MONTH!

A few specials we'll be working on this month!

     Due to the Diamond / Cerwin Vega closeouts, we also got our hands on some WCC, (West Coast Customs), speakers that were made by the factory that also makes some of the Diamond and Cerwin Vega products.

     We have the WCC680 convertible 5x7" / 6x8" components. Use them as a coax or separates, it's up to you! $55 shipped!



     MSRP was $199 but we have them for $55 a set shipped and limited to 25 sets.  As with all our deals, we can drop ship to your client with your return address, (Blind drop ship), so we stay underground and you're the hero.


     We received a new shipment of the new MA Audio HardKore motors and are already building them out to order.  We're doing the 15" in either D2, D4 or D.75 ohm setups with SPLX frame for only $263 shipped!  (Add $15 for extended 60mm tall coil.)

     You even get the Audio Pulse, aircraft grade aluminum single dish cone with tall, patented NBR surround by TC Sounds.
12" version is $250 each shipped. (Lower 48)
Thanks again to MA Audio for donating their old magnetizer to us at a great discount!




     Not pictured are the 10" version and 18" versions.  We have several cone options to choose from so prices will vary on how fancy pants you want to get with those, but are based on the 12" and 15" pricing.  We do not have 8", 10" or 18" Audio Pulse cones at this time.
   
     The new style HK motor is shown on the SPLX frame with the SPLX, (TC9+ motor), to the right for comparison.  (No more fins, yay!)


   


     We also found another stash of the old Rockford White Wolf 3m RCA's.  These are some of the best built cables on the planet!  Get a set for only $30 each shipped to anywhere in North America!  We also ship worldwide and they come in the original box as pictured.  Some still have the Best Buy pricing tags on them as well.  These are a STEAL compared to the prices you home audiophiles pay for a quality cable like this!!!

      These are available to Rockford Fosgate fans all over the world too.  Thank you for your support!






     Rockford Triple X series RCA's are available out of the packaging and tested as well!  We have pallets of RCA's and other cables and we can also custom make several rare cables so email me with your requests.

The 1m is only $16 shipped and 2m is $25 shipped






Thanks again for your support!
Patrick Chandler
Co-Founder of Robot Underground


Friday, January 25, 2013

Why do you do it? Why not for profit? How to build a Robot PART 2

Read part 1 HERE

Step Four:  Let the Wrecking Ball Fly

     Whenever something is built, something else must be un-built / destroyed.  These are not my rules, these are the rules of the universe.  The universe on both the large scale and the very tiny are in constant expansion and contraction, ebb and flow as it were.  When I started my journey, I had no idea of the destruction I would do just to follow my dream.  I didn't mean to harm anyone, in fact I did my best to help others.  What I realize now is that no matter what you do or what anyone else does in this world, there is always give and take.  Every time you help someone, you also hurt someone or something else in order to do it.  Think of all the millions of sperm and generations of people that have died so that you could live.  In order for me to live other things have had to die.  Cows and Chickens top the list.  In spite this, many of us still reach for The Light to make this a better society and generally a great place to live and die.

     If you do something great in your life, expect resistance from others.  Family, long time friends and you may even be betrayed by both to keep you in (your) place.  Governments, agencies and even the Universe may be on this list of resistance givers, (haters).  (Yes the Universe can hate on you).  The trick I've found to being efficient at this is patience mixed with timing.  Sometimes it can't wait but if it can, keep it and wait for the right timing to make your move. To go with the flow as it were.  That requires observation and conscientious action.  If it can't wait, don't be surprised when it's more work that you'd like or thought it should be.  Owning the decision, (follow through), is always a required ingredient to getting to your goal.  At then end of the day, enjoy the fact that you are pursuing a life of adventure and it's a privilege to do it.  The attitude is simply to be grateful.  Even what seems as a life of survival can be turned into adventure by a simple change in attitude.  I'm sure there's a quote somewhere of something like, "Only loving what you have, can you have something else." or "You cannot shake hands with a closed fist.".  The secret is gratitude and that then allows you to enjoy the ride and then everything becomes an adventure.  This is reflected in our mascot, Ohmey.  His mind is always 'open' to allow The Light inside.



Step Five:  Replace Yourself / Get the Robot(s) Running


     Patience and timing are especially crucial to this step.  In order for this project / life to really do something you need to replace yourself. You need the help of others.  You can do this with projects that you do, books or blogs that you publish or even just raising children that don't burn the house down when you decide to go out for a night on the town.

    Our ideas, discoveries and self reflection are what's missing in the world.  In other words, consciousness.  The outward expression of consciousness is change.  To make corrections around us and align ourselves with The Light.  This is where the employment of robots or any device that allows you to leverage your time and knowledge to move you closer toward your goal / life achievement.  The internet is by far the most important and under utilized tool in your arsenal.  This tool at it's present state is still just a tiny flag in the top of an iceberg the size of the Death-Star, we have only scratched the surface.  An even greater asset than that is of course your mind.

   Align yourself and your robots with people and organizations that do this for other people already.  Learn their secrets and watch their moves. (Patience & Timing)  Then when you see the cogs flowing in the right light, jump in to seize your time in the machine and move through without a scratch.  This is where "applying yourself" comes into play. If you want to be good at business, study businesses.  If you want to be the master of Yoga, study everything you can learn about Yoga.  If you want to own the market on Yoga businesses, study franchising and clique culture along with everything about Yoga and Business.  Once you realize their tricks, the secrets of their success.  With the right timing and positioning,(more timing and patience), the world can be yours.


Robots Running!
Patrick Chandler
Co-Founder Robot Underground
   

Tuesday, January 22, 2013

Diamond Audio 2012 Closeouts - Make An Offer!

SOLD

Still have the amps left.
$500 ea. - 2 pcs - HA750.1 - 750wrms 1ch, class D & 1 ohm stable, (JL HD750 is not 1 ohm stable)


Again, do your research and make an offer!  All items here are new in the box but do not carry any warranty.  All sales are final and again, thank you for your support.


Patrick Chandler
Co-Founder - Robot Underground

Monday, January 14, 2013

Killer sound from the factory head unit / why BLT's are killing you or at least your wallet.

  I was going through my files and I found one that Brian Smith had published in Car Sound & Performance Magazine that I thought is a great tool for those dealing with OEM systems. (Almost everyone)

  I love the factory radios now.  I love the look, the feel and simplicity that the OEM has gone through all that hard work to put in front of me.  New cars even have application based radios and having an AUX input and the ability of playing MP3 from a disc have been in cars for years.

  I often find myself telling clients what they're not used to hearing.  "Keep the factory head unit."
Aftermarket decks are expensive and are often an unnecessary habit that car audio fans keep shelling out for year after year, car after car.

  BLT's are killing you or at least your wallet. Balanced Line Transmitters, (BLT's), are a waste of money.  Even if you just look from the standpoint that your cable distance.  You're not 20'! At such a short distance it's overkill to spend money on such a thing.  (We'll get more into that later, also why do you need 8v pre-outs when you can run your amp into clipping with as little as 3/4 of a volt???)  Many great amps of the past were waiting for you to employ this technology but you didn't even know it.  Take the PPI PowerClass amps.  They use a differential input and even put an optional -12db filter button there for you.

Check out this article by Brian Smith, (NOT ME!). (Brian nor Auto Media Mag could be reached for this post, though last time I checked AMM was out of business.)

Output Alternative
Learn how to make the most out of a head unit's balanced, high voltage, low impedance output section.  By Brian Smith

     In a recent issue of Car Sound & Performance, I made an offhand suggestion about using the speaker outputs of one of those high-powered head units as high voltage pre-amps.  I received several questions via e-mail on the subject and it appears that I wasn't the only one.  Occasionally, our editorial staff will send a topic for these monthly columns, especially if the subject matter seems to be of widespread interest.  This month the question was: What type of input stage does an amplifier need in order to accept input, (in an OEM system), without an LOC? (LOC = Line Output Converter)

     Ooof! The answer is unlikely to make the LOC people, (manufacturers), happy, so I guess that I'll try to soften the blow by stepping on the toes of the line driver folks as well.  Here goes... You don't need any particular type of input on the amplifier, you just have to know how to do the correct interface --- and, almost all head units available today, including OEM and even super-cheap aftermarket units, include a balanced, high voltage, low impedance output section.

     Let's begin with the head unit.  This is going to take a little math and a few diagrams, but hand in there.  It's really not that complicated and there are some definite advantages to be gained.  The block diagram shown fig.1 represents a single channel of the amplifier section in the head unit, way back in the day, when car audio was something relatively new.  This arrangement was capable of a few watts into typical speaker loads, (for this example, we're going to say 4 volts across 4-ohms for an output of 4 watts because it makes the math easy and it's not far from reality) but consumers wanted more power.  One way to increase output would be to add a step-up transformer to the output of this small amplifier.  However, good transformers generally cost more than the rest of the head unit.  Another approach, and the one that was ultimately taken, was to bridge a pair of these small amps (see fig. 2).  This configuration provides twice the voltage, (8 volts), and therefore, 4 times as much power (16 watts) into the same 4-ohm load.



     Now, toss that 4-ohm speaker and consider and consider driving the input of an amplifier with this output.  Yes, you can drive an amplifier with another amplifier.  Typical input impedance on a modern amp is usually in the 20kohm range.  Plug 20,000 into Ohm's Law in place of that 4-ohm speaker; the 16-watt amp will only output about 0.003 watts, so we're not talking about burning anything up here.  That being said, what we're left with is an output section that swings +4 volts RMS between transistor "A" and ground and -4 volts RMS between transistor "B" and ground, or, a total of 8 volts RMS.  The term 'balanced' comes from the fact that the positive and negative potentials are equal relative to ground.

     Balanced inputs make use of a special design called a differential amplifier.  This device accepts two signals, inverts one signal, and then combines the two.  If you send the signal that you want to one input and mirror image of that signal to the other input, the device's output will be exactly what you sent to the first input.  While that sounds like a silly way to go about getting what you already have, the side benefit is the cancellation of any noise that may be induced into the signal cables between units.

     Most modern automotive amps have balanced or "differential" inputs, inputs that are designed to accept exactly the type of signal that comes from the internal amps of a head unit.  Yes, I'm saying that you should be able to solder RCA plugs to the speaker out wires and drive most amps.  So, why is there even a market for LOC's and balanced line drivers?  Probably because someone tried this trick once and the resulting system was noisy --- remember, I said "should" and "most."  If the amp in question has a single ended input (i.e., non-balanced), connecting the head unit in this manner essentially shorts device "B" (shown if fig.2) to ground.  This condition is unlikely to produce either noise-free performance or long life expectancy for the output device.  There is also the consideration that some amplifiers with "balanced inputs" prefer to have the low side of the differential input tied to ground.  This is how the signal chain happens with the single-ended preamp outs on most head units (see fig. 1 again).  So, some manufacturers base other aspects of the overall amp design on the assumption that this will always be the case.  I've certainly heard the "low side to ground" mantra on a frequent basis, but I've only seen a couple of cases where it appeared to make any real difference.  In most cases, tying the low side of the input to ground caused a slight drop in low-level distortion.  I'll trade a couple of hundredths of a percent of distortion for some ground isolation any old day, especially in a car.

     The main gist here is that you need to determine what type of input you're dealing with.  Balanced inputs are usually mentioned in the feature listing if the amp has them, but here's a quick test that will tell you which type of inputs you have.  With a DMM, measure the resistance between each of the RCA's outside contacts and the amp's power supply ground connection.  Also measure between the left and right RCA's outside contacts.  If you see anything below a few ohms, then you've got a single-ended input and you're going to need a single-ended output like the one shown in fig. 1 to properly drive the amp.  To achieve this, you'll need to take the output signal from half of the bridged pair shown in fig. 2 (see fig. 3).  This can be done by connecting the center pin of an RCA connector to the + speaker output and the ground sleeve of the RCA to the chassis of the head unit; no connection is made to the --- side of the speaker output.  Of course, this configuration provides only half of the available voltage but that would still be a 4-volt preamp with our middle-of-the-road example of a 16-watt amp.  There are many more powerful models available, and when you stop to consider that the source impedance of the amp section could easily be 100 times lower than a good preamp section, this approach begins to look awfully attractive, even in an unbalanced configuration.


Again, this article originally appeared in the Tech Briefs section of CAR SOUND & PERFORMANCE, year 2001, (or so), by Auto Media and was authored by Brian Smith, NOT ME.

Patrick Chandler
Co-Founder Robot Underground

Tuesday, January 8, 2013

Dynamat, Fat Mat, Accumat, Boom Mat, DLS Max Damper, B-Quiet, Hush Mat, RoadKill, Alpha Damp, Dead Skin, Second Skin & Turd Skin... Which damping / sound deadening mat is best?

Which damping mat is the best?  The quick answer is, you probably don't need it in the first place and if you do get some, it's all the same.

If you do think you need it, lets look at the hype vs. science.

There are many, many brands of damping material.  Dynamat which is one, if not the original damping mat brand on the market.  It's a top tier brand and is one, if not the most expensive brand.  Dynamat's claim to fame is that you get +3db or twice the amount of sound from your system by using their product.

This claim is supported by damping or deadening your listening environment to lower the road noise in your car, thus lessening the power requirement needed by your stereo system by half which is equal to -3db.  First off, -3db is not very much at all, however this claim is sort of true but in order to achieve it, you have to use hundreds of pounds of it.

Lets look at the original low road noise listening environment, your home.  Home audio systems can use a  fraction of the power of a typical car audio system and still sound fantastic!  The secret to great listening environment air isolation.  Air isolation along with vibration / distraction elimination are really what make a system sound great whether it be home, car, RV or spacecraft.  Because air is what transfers sound to you, if you want the sounds outside to stay outside, make your listening environment isolated from those sounds.

For homes, most use a typical double wall system with fiberglass insulation in between to hold still even more air in place. (Outer sheath and drywall inside surrounding fiberglass, straw, shredded blue jeans or newspaper).  Other techniques like adding a vapor barrier as well as encasing the home in foam and then stucco or siding increase the isolation through multiple barriers to keep the outside out and the inside in.  Windows of course increase their R value, (Thermal Resistance), if you use a double or even triple pane design for the best isolation or R value..

For cars, the same practices can be employed to greatly enhance your car's ability to isolate the air.  Many of these techniques are already in place for high end cars.  I'm not sure if Lexus still does it, but they used to make a big deal about actually laminating dual walls of steel with a soft center to reduce noise.  This also helps keep the transfer of heat and cold to make it into the cabin as well.  Mercedes Benz has been known to utilize double pane glass to aid in this as well.

Most car makers just use asphalt based damping material.  I find it funny that many sound damping material enthusiasts will actually go through the effort of removing this damping mass to simply add their newer version of the same material.

How it works

Damping mats / sound deadeners works in two ways.  The first is by changing the resonant frequency of the 'noisy' panel in need of damping. (Yes the material also turns vibration into a tiny amount of heat but the heat signature is very tiny, barely worth mentioning.  The mat will not feel hot after a big bass session.)  The mass, any mass for that matter will change the resonant frequency of the panel.  The mass need only to be attached firmly enough to withstand the flex of the panel.  This added mass simply lowers the resonant frequency, it does NOT remove it.  When the resonant frequency is lowered to a frequency that is no longer audible or at least no longer annoying, mission accomplished.  Any added mass does not add to your audio efforts.  If you want to add to making your vehicle louder, you'll need to remove noisy devices / panels by either strengthening panels and or bracing.  This eliminates the transfer of energy from inside the car to the outside.  This is why having your buddies lay all over your car during an SPL run pays off.  Your ride is not well braced.

Damping mats do not strengthen your vehicle, they only add mass.  With this in mind, you can use an infinite number of devices and methods to add mass to your noisy door and body panels.  Some brands, (Second Skin), would actually sell a device known as an, "SPL Tile".  This was simply a normal, everyday and very cheap ceramic tile glued to your door panel.  Did it work?  Yes.  However the video by Buzz was taken down due to the quick erosion of marketing advantage, (People realized the doucheyness of someone selling you something you can buy cheaper and without shipping down the street rather than online.), and replaced the product with simply a small section of the same damping mat that comes in rolls, the name stayed the same.

I actually pointed out this idea by making your own damping material on the DIYMA forum.  Little did I know that the forum was owned by Ant, (Anthony Collova), who also owned Second Skin at the time.  When asked if I included Second Skin as one of the products that just add mass and are overpriced, I agreed.  I do apologize to Ant as I assumed that a forum called DIY Mobile Audio would filled with ways to DIY, (Do It Yourself).  My post there was unfortunate and out of place.  I just wish, this video, were in place before I posted.  Now I know better and posting that information here is more appropriate.

So if you want to make your own damping material for your car or boat, the recipe we use is equal parts of siliconized acrylic calk mixed with pure silicone calk.  Your added mass can be sand, we use 30 grit from the masonary store.  You can also just use pebbles, washed gravel or rocks, lead / fishing weights or even a tape dispenser.  Other items include Amy Riordan's old retainer , broken speaker magnets or my favorite, all the lead droppings found at the shooting range.  All the materials can be obtained locally for most users.  For users that come see us locally, that don't want to do this and refuse to go to the hardware store to buy their own Peel & Seal; we sell de-badged Peel & Seal for $30 a roll and we still sell about 2 rolls a week.  Go figure.  You can also order the Peel & Seal under the Mule brand from many roofing wholesalers.  Alibaba is also a great site to check out if you feel like importing a pallet or two for you, your friends or your shop.

Remember that with the use of any damping material in your ride, you're adding weight.  The typical application for a loud system user, the amount needed for complete damping of a car is several hundreds of pounds, several layers of material.  Then add in the weight of the equipment and you'll need to beef up the suspension to keep up with all of that mass.  You of course compromise fuel efficiency and handling for a quiet ride.  Hopefully you didn't ignore the door jams and firewall after spending loads of cash for something you could have bought locally for much less and your car is pretty awesome in the first place right?  If this is not the case, this good sir, makes you a Douche aka a Bro, bro.

You can however redeem yourself if this is just a case of ignorance.  Correct your course and the musk will fade from your ride over time. However, if you continue to use machismo and cash to solve problems, you are on a crash course to hanging out with Ant, (4:35), doing totally non-gay things like showing off your muscles with other mostly naked dudes.  You can totally smell the macho nachos!

To wrap it up, educate yourself.  The most valuable real estate is the gray matter between your ears.  Hopefully what I've shown today will save you money and most importantly, time.  Remember that branding can be blinding.  Take commodities for example.  In the grocery store, do you care what brand of sugar you buy?  It's all the same stuff and even comes from the same place, but some people do care and are willing to pay more for for it.  As a consumer this is a rip off.  As a vendor this is the art of branding and marketing.  She's a lovely devil that will always have you wanting more.  However when followed blindly, she will screw you, bleed you and roll you. Use your head, pick your compromises and don't be afraid to change your mind when everyone else is doing it.

Patrick Chandler
Co-Founder of Robot Underground
robotunderground@yahoo.com

Sunday, January 6, 2013

Email Me!

I'm still learning how to be a good blogger so please email me with comments and questions anytime.

I'm talking to you Nick!  Thanks for the comments.  Email me with your info and links!

robotunderground@yahoo.com

Why do you do it? Why not for profit? How to build a Robot.

A great client came by today.  He was dumbfounded and amazed at the value he received... The Bang for The Buck as it were.. He ended up with a single 12" D4 SPLX rebuild, (HardTimes Pro), sub powered by his 900w Kenwood Class D amp.  He'd gone through a couple of upgrades, this was the final stage.  After hearing it I answered a few more of his questions, but his last question stuck with me.  "Why do you do it?  Why not for profit?"

I'm often asked this question but I tend to give a brief, superficial answer rather than any detail.  The subject is actually quite sacred to me and isn't usually for the masses.  

Most people just don't get it and I'm fine with it at that.  When others want to learn more, I can show them at that time, though the rabbit hole is quite deep.  

I was reminded this week by an interview on NPR as to the real reasons I do this project.  The answer is simply, "Happiness".

The Diane Rehm Show is one of my favorites.  This week, Sonja Lyumbomirsky was promoting her book, "The Myths of Happiness".

I encourage you to download the podcast and give it a listen.  To me, this information is the key to a prosperous future world.  Mastering this information / technology will bring a new, exponential, level of wealth and prosperity to the world.

Little did I know, through trial and error, I'd been privy to this technology for many years now.  Helping others is the key to happiness.  Lasting, satisfying happiness.



How to Build a Robot in 5 easy steps.

In school I was a solid C- student.  Teacher after teacher would say, "He has potential but he doesn't apply himself."  To me, public schools were a brainwash and a joke.  I wasn't interested in anything but skateboarding and girls, (In that order), until I discovered audio.

Once I was infected with the Audio Bug, I began reading everything I could get my hands on.  I actually used my knowledge learned in Car Audio magazines to get me through my Air Force technical school.  Once I could relate, I became one of the best students in the class.  I was happy to go to school and happy to showcase my talents of troubleshooting and network design.  I finally found my purpose!  Something I was good at and everyone else thought was hard to grasp.  I felt very empowered and excited about life's possibilities!

Not everyone was happy with my obsession of woofers though.  Especially my bosses.  I was always getting in trouble.  Even though I'd already finished my work I needed to look busy.  I hated looking busy.  I wanted to be 'real' busy.  So when I was off the clock, I did installs and designs for very cheap or for free.  I was just glad to help.

So then my wife was unhappy I was spending all my extra time with others.  I'm sure many of you can relate.  Many people end up with the answer being a different spouse and change over and over with the same results.  Many people just change obsessions, like MMA, Off Road, Guns, Wood Working, Cars, Food, Sex or just working out at the Gym.  All of these changes still end in the same answer when balance is not a priority.  Many still suffer in silence and are never genuinely happy.

For me the answer was obvious but I didn't get a real opportunity until the ADST bankruptcy in March of 2003.

ADST was the former parent company to brands like a/d/s, (Analog Digital Systems), Precision Power Inc., Apogee Home Audio and Orion Industries. 

The Phoenix Metro area was home to brands like MTX, Coustic, Xtant, Lightning Audio, Hafler, Rockford Fosgate, Diamond Audio as well as the ADST brands.  At the time, I was an avid dumpster diver / scavenger of the remnants of these big brands.  You could always find someone in the paper that would have a surplus of this or that in those days.  Like when Rockford bought out Carbnneau, there was a flood of great woofers that nobody ever heard of! It was great.



Step one: Get your foot in the door.

So I show up to ADST late on a Friday afternoon when usually everyone was already gone for the weekend.  Surprise!  The parking lot was filled.  Pat who worked in the warehouse and who now helps run Precision Powerdercoat, a former vendor of ADST, spotted me and asked what I needed.  I quickly just told him I was looking for, uh, uh, yeah, boxes.  He told me, "Come back tomorrow for all the boxes you can haul at the bankruptcy auction."  

Auction?!  Orion was out of business?!  I took action immediately but had no idea what was in store.  The next day I showed up with $5400 I borrowed. When I asked them for the loan, they asked me how often these companies filed bankruptcy.  I told them once in a lifetime for brands like these.  Funny how far a little trust and enthusiasm will get you.




This was my back porch.   Sinks galore, amp end plates for miles and I had no idea what I'd do with all those voice coils!

One of my favorite deals from the auction was a whole double pallet lot, 5' tall, of the XTR Pro cones for $5!  I thought everyone there was on crack for passing up such a deal.  I had no idea what I was going to do with all those cones but I didn't care.  I was excited just to be there.  Most of the guys there were either there as scrappers, (people that buy items for their scrap value), or retail guys there to snatch up a minty GS 500 for $10 or something.

Many of those guys used up their couple hundred bucks and left when their consumer ideals were bloated.  Not me, I knew this was what I was waiting for.  I had to run back and forth across the warehouse.  They were running two auctions at the same time.  One side for the parts and one side for finished goods.  I was so tired and sore the next day.  I didn't want to leave for a bathroom break or even lunch.  I finished out the auction flat broke and really tired.  Now I had to figure out how to haul all this back to the house I rented.  I never even told my wife about it.  I just showed up with loads and loads of boxes.

Well with the help of a couple of buddies and lots of trips back and forth we were able to stuff my house from top to bottom with just boxes and boxes of speakers, crossovers, wire, amps, parts, promotional items and just stuff that as a consumer, you'd never be able to get at a car audio shop.  While this was going on I was still looking for a job.  I'd been out of work for several months.  I got a call about a job in the Bay Area for AT&T.  So I packed my bags, told my wife not to open anything until I got back.  I was to teach new people about telecom and electronics but I basically helped AT&T call the bluff on the union strike.  The job lasted just 2 months but it was enough to pay off the money I borrowed and give me seed money to get started.  That was the last time I've worked for someone else and I had no plans to go back to that life.



Step Two: Make your presentation

I spent the next year blasting it out on eBay and buying up other stashes from people who either didn't know what they'd bought from the auction or just how to sell it.  I happened to be good at both.  With some help, I decided that formally organizing Robot Underground as a not for profit was the best fit.  My main focus was education, not sales.  I know I didn't want to be like a shop.  That's why I started doing all this in the first place.  I hated high pressure sales and misinformation.  I realized that was not the direction I wanted to go so, the choice as a not for profit seemed obvious to me.  

I was fascinated with projects like RTTI from Rockford.  Rockford would truck in people from their authorized dealers to educate them on being better installers, sellers and fanatics.  Education was the key to getting quality installs and better selling.

As a longtime consumer, I always wanted the sales guy to answer my technical questions, show me my options, make your recommendations but leave it open ended for me to make the choice.  I've always been a fan of  the movie, "Miracle On 34th Street".  The idea that a sales person would make the customer's best interest a priority is still a rarity and a delight when experienced.  Anyone that's ever shopped for a lawyer, car or television can tell you what they don't like about the process.  My Robot experiment was on it's way! "If it is to be, it's up to me".


Step Three:  Follow the rules, (Golden Rule)


Sometimes I'm a bit too optimistic.  Selling online looked easy and for some reason I thought that eBay would want to help me.

We no longer sell on ebay but you can review the feedback on our original RobotUnderground account, (Now Worldwide-Revolution, eBay wouldn't allow us to have the email and name the same, then we couldn't put our email address in ads, then we couldn't put the phone number, 602-312-6504). Then after a few uptight buttholes ruined it for everyone, I lost my PayPal account.  I started over with JuicyRobot, (The name is now Underground-Industries).  You can see over 9000 positive feedback combined.

My optimism got me into trouble on the forums as well.  I initially thought it'd be great just to peek in and get feedback on some of our products.  I answered a few questions and even put some questions out there to challenge some of the common audio myths.  BEWARE OF TROLLS!

I had no idea that the forums were little clubhouses where the rules could change at any moment, for any reason and are filled with unpublished agendas.  I quickly learned about cyber-bullying when a former client decided to post his complaint on the forums rather than deal with us directly.  I did my best let him know that I meant no harm and quickly gave a partial refund.  I quickly realized that a complaint can turn into terrorism when children don't get all they can get.  People started coming out of the woodwork and starting fights where I didn't even know there were any.  Everyone of them was out to get something for free and I didn't think it was right to do that.  Boy did I pay, so I thought at the time.

One guy even terrorized me for days, through email, craigslist and on the forums then followed it up by killing himself.  I quickly wanted to point out that this guy was nuts and this proved it.  The tone on the forums though was that somehow it was wrong for me to post in my defense because this guy was dead and could not defend himself against my accusations.  The biggest insult was when the moderators started censoring my posts.  People actually blamed me for this idiot killing himself.  Again, over things he wanted for free that I wouldn't give him and didn't owe him.

Later I found a great video about cyber-bullying that I think everyone should see.  Bob Parsons, founder of Go Daddy does a great job giving advice to anyone wanting to do business online.  View the whole series, they're great!

Some people think I ruined my online rep of Robot with those posts.  My view could not be more different.  For me this was a great thing.  The truth is in the posts and in my defense but it requires effort to view it.  For someone who's lazy and enjoys drama, it's a kick in the teeth to me and to Robot.  What I found out is that people who don't want to see the truth; who'd rather believe gossip and bad-mouthing than see the good in what I'm doing with this project.  These are indeed the same people I don't want to deal with anyway.  I know the truth and that's all that matters.  I know I have good dealings online and in person.  Good people see this.  Bad people see the drama and the dirt and go back to the macho driven hype and cliques.  I also didn't realize the threat I would bring to old distribution system and those that still use it; be it shops and the brands they support.

Again, I had to remind myself why I do this.  To help people.  The trick is to only help those who ask for it.  Unsolicited help is intrusive.  As good as my intentions are, many still see my actions as intrusive and it's vital that I acknowledge that.  It doesn't mean I'm going to quit.  It just means I need to be more creative in my efforts.


Step Four:  Let the wrecking ball fly 

.....More in my next posts.

Patrick Chandler
Co-Founder of Robot Underground