One Graph -- Two $500 solutions for bass

[RoboKlipsch]

Often I see people ask about whether they should buy something or build something.  If they build something, does it need to be expensive, involved, difficult?  What benefits are there to building something if you are on a limited budget?

 

This is not designed to convince anyone of WHAT to buy, just to illustrate the benefits that come from something that has both capability and EQ.

Klipsch -- whose forum this is -- makes some terrific subs.  I have owned a few of them myself including an RSW15, which is a monster.  

So again the purpose here is not to show what is "best."  It is to illustrate two different lines of thinking and the benefits you can acquire.

 

Option 1:  You buy, either new or used, a couple of name brand subs.  They aren't superstars, you aren't rich, you've got maybe $500 max to spend (new), or perhaps you spend $200 - $300 used on a pair of subs.  This is easy, fast, looks good, and will boom nicely for HT.

 

Option 2:  You build something, cheap, because you aren't rich.  You want good bass, something that goes as low as possible but you aren't spending hundreds or thousands of dollars on drivers and the like.  In this case, I picked up 4 inexpensive car subwoofers, along with 2 enclosures.  I paired them with an INUKE3000DSP (The "DSP" allows for many features but most important for easy comparison is the ability to "EQ" the subs.   With some creativity and looking through craigslist, one could get a similar setup used for potentially 300 or 350.  $500 new. 

 

Here is the results of both solutions, deployed in the exact same room.  Note that the 2 name brand subs were put up front behind chairs by the fronts.  The car subs were in boxes with 2 in each, so one was placed in the center of the front of the room behind the TV, one was placed in the back of the room (upright, to take up minimal space).

 

The graph:  

 

The RED LINE is the 2 subs easily purchased new or used at a store.  The BLACK LINE is 4 subs, 2 in each box, along with an INUKE3000DSP.  Note if purchased new, the comparison is roughly the same, and the cost is roughly $500 for either.  

 

What does this sound like?  The red line sounds like most of your friends houses that have a HT system.  When explosions go off, it booms big time.  Listening to music is exciting, but there is some muddiness to it.  As you can see from the graph, when listening to home theater, the subs disappear by 25hz, and compared to their peaks, are really disappearing closer to 30.  Due to the fact that there is no EQ here, and no autocorrection (YPAO, Audyssey, etc) there's no way to improve this graph except by moving the subs.  This was the BEST I could find!

 

The black line represents the response of the cheap car subs, EQd to almost flat.  In fact, this is a representation of the average of 3 measurements across the couch versus the best, center position for the red line!   Notice that within a typical usable range for subs (say, 20 to 100, they are flat, and within a +- of a few db.  Imagine if Audyssey or another correction system got a hold of this, you could have pretty much a flat line.  When I actually am using the car subs in action, I have what is known as "DEQ", or dynamic EQ in place.  This allows the system to raise the low end of the subwoofer more when the volume is lower.  This means that when listening to home theater or TV at lower volumes, the system compensates for the low sound volume by increasing the low end until it sounds much like at higher volumes.  I am not illustrating that here in the graph, so that it doesn't complicate things.  But that extra flexibility is a great feature, it simulates what is done in Audyssey and other technologies.  

 

So which do you want?  Obviously, when it comes to higher end store bought or ID subs, the performance can match and surpass what you see from the car subs.  But the point here was to say, if you are on a budget, what is the benefit of building -- or buying something -- that is not simply a store sub.   Going outside the big box, so to speak, offers some excellent potential benefits.  

 

The other lesson that could be learned here is the value of a measurement microphone.  How many people hear their systems, think they sound great, and never realize what they are truly missing?  Everything is a guess until you actually measure.  Guessing is fine, measuring is better   

 

Please feel free to add, criticize, comment, or take this in another direction as you may see fit.

 

RK

 

[derrickdj1]

My take on this is the power of additional DSP that is not available on most plate amps.  Also, how the extra DSP can give you control to dial in the subs.  To many times I hear the argument of one sub beginning bad and the need to purchase another sub.  Most times the problem is not the sub but, the lack of ability to dial it into the room.  Even looking a the manufacturers specs of how flat the frequency response has little meaning since it is an outdoor or anechoic measurement from 1 or 2 meters.  This tells you nothing about how it will be in your room with long sound wave bouncing around the room.

[jjptkd]

Yes, car audio subs can be a nice, cheaper alternative to pricey and often inferior store bought home audio subs. I myself currently run a Sundown SA-15 sub in a pre-built cabinet designed for use in car audio. Total cost for the brand new driver and cabinet delivered to my door was $350, minus an amp of course. I have no idea what the response looks like as of yet but know it has no problem belting out sub 20hz bass that rattles my room like an 8.0 earthquake if I want it to. Eventually I plan on picking up a miniDSP and Mic to do some testing and adjustment but right now I have the sub crossed over at 40hz and let the towers work the rest. In my small room it sounds great as is.

 

 

 

[RoboKlipsch]

i think car audio is fun but most would not play low enough in a theater.  just need to be selective and find a good driver cheap.  parts express has many levels of performance for ht subs too.  dj is right about peq.  but dont discount deq the dynamic version.  having strong bass at low levels is not easy without it.  it allows for a curve that changes with volume.  it can mirror audyssey.  which is yet another option....audyssey with any subs.   but that can get pricey

[jjptkd]

I have a 20hz test tone I've played through my sub and it really moves the air around without making audible sound, it literally feels like an earthquake when I turn it up. I have no idea how much lower that sub is capable of going but I know I hear / feel things in my test tracks that can't be heard or felt with my buddies 18" SI sub which is tuned at 20hz. The Sundown 15 seems to hit lower than my Sunfire Signature 12 which is rated down to 16hz so right now those are my points of reference. Admittedly the Sundown does lack in the upper bass department so its not a well rounded sub in terms of overall response but I'm sure some sort of DSP could help but not needed currently.  

[JohnA]

RK,

 

LOL!  The center of the front and rear walls are known to produce the smoothest in-room response for 2 subwoofers.  The most practical optimum location and number is 4 subs positioned in the center of all 4 walls.  Your comparison is mildly flawed, but you have an excellent point that care and judicious EQ solves big problems.  I hope my system is that smooth! 

[RoboKlipsch]

I tested the 2 subs front and back and did not get good response.  With 4 they are in dual boxes so no ability to spread them.  Dont assume anything though the study is real but each room is different and 4 midwalls is not the best necessarily in many ways.   I consider the 1/4 from corners the best starting pt for better bass.

[SiliconTi]

Hey Robo, thanks for posting this. I always prefer DIY to store bought.

 

What drivers/boxes did you use?

 

Do you think the 3000DSP is needed? Could you get away with a 1000DSP or 2000DSP and save some $?

[RoboKlipsch]

i used infinity 1260w drivers in boxes w 1.83cft each driver.

 

what amp to buy depends on what you build.  for example these subs have some low end eq added which takes up amp headroom.  i think it models to only 100w or so per driver due to excursion limits.  but the eq causes it to need maybe 400 or 500 per channel (200 to 250 per driver)  so it is hard to suggest a 1000dsp as any eq takes it above the capabilities.  the 3000dsp is a  sweet spot in value and can be wired to 2ohms in some cases allowing for a lot of cheap power.  they were on sale at amazon for about 230 recently.  look for a sale or used for a good deal.   6000dsp for multiple 18in subs. 3000dsp for others imo.

[SiliconTi]

Thanks!