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Discussion Starter · #1 ·
Can anyone recommend a good cheap amp for two 25amp Aura Bass shakers?

I don't really want to spend $300 and I am not too crazy about the rack mount one's on Parts Express...


What do you people with bass shakers use?

Thanks in advance for any suggestions!
 

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If you are going to run them in series for an 8 ohm load you can pick something up at Circuit City or Best Buy in the 80 dollar range for a 2 channel receiver that will work fine.
 

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Discussion Starter · #3 ·
Thanks, Phyre3, I will check those places...would this be a sub amplifier, or just a regular cheap amplifier?
 

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I bought a sub amp from Ebay that is exactly like the ones sold at www.partsexpress.com .I like using this because it has a level control and an adjustable crossover to limit what frequencies shake you. If using a reciever only, make sure you can set the crossover to filter out all but the LFE.
 

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Discussion Starter · #5 ·
Thanks, Milesed...I saw those amps on Ebay, and the "Buy it Now" options are actually cheaper than PE's price...I am reconsidering those...probably a dumb question, or it may be in another thread elsewhere (?), but how do you hook up the Aura's to those amps? The auras I got have spade connectors on the end of the wires...
 

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I used 50 watt Auras and they had a different type connector. I used a splitter from Radio Shack at the sub's pre-out and sent one to the real sub and the other was spliced to the sub amp's wiring. I ran one speaker wire to the shakers. I needed to match the 8 ohm impedance of the sub amp. Therefore, I separated the speaker wire into its + and - wires for a few feet and connected the positive speaker wire to one wire connection on shaker #1. From the other wire input on shaker #1, I ran one wire to shakers #2 wire input. Then I connected the other half of the separated wire coming from the sub amp to the shaker #2's other wire input. This basically takes one wire (cut into 3 peices) running like a circle to the shakers and back to the sub amp. I can't remember if it's called " in series" or " in parallel". You may end up needind to splice bare wire depending on the connections available.

I know that this sounds confusing, but I searched avs forum for the above instructions. With help from here and the enclosed wiring directions with the Auras, it was quite easy. You might search the forum and the Aura website if you don't have any instructions with your shakers.
 

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Discussion Starter · #7 ·
Thanks, I believe that is in series, and I saw those instructions somewhere here in forums...The shakers I got appeared to be packaged for car installation.

Thanks again!
 

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Add: the Aura website is at www.aurasound.com . If you click on bass shakers, then on home installation guide, it will show part of what I outlined above. If you take their pic and add a wire between the shakers that is my set up. I saw the 25 watt shakers you have and I think you can just strip and splice the wires with speaker wire to and from the amp.
 

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Campers, we need a "how to power yer bass shakers" faq...


Run the cable from your LFE to a Y-splitter, and run one side to your sub, and the other one to the shaker amp. Split it again if you want to.


This shaker amp can be darn near anything, as long as it'll work between 20hz and 100hz. I _heartily_ recommend checking your local goodwills/salvation army stores for old receivers. I was running my shakers off an old Marantz 2230 with no problems, but a "cheaper" receiver would work just fine. It helps if you can turn 'em off for music. I wired two pairs for two 8 ohm series "units" and bolted 'em to the sofa. You don't need a new amp - just one that will produce 25 or so watts/channel and handle the low end. I run the Marantz with the high filter on, the loudness button on, and in mono mode.


I've tried running 'em with the takeoff plate amp from my DLS-10, and it works okay. I like the looks of the Marantz in the stack tho...


Spade connectors? Isn't there a reason about why Bob made little butane soldering irons?
 

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Just a little odd coincidence but I am running a pair of the 25watt Auras off of my old Marantz 2238 using the same setup.


You really want an amp that goes below 20Hz most actually do but the roll off point is listed at 20Hz.
 

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I'll through this into the mix, as I'm considering the bass shakers as well, but am totally clueless on how do set this up. I'll look for everyone's expertise on what I need to do.


I'll have 7 recliners. I would like to put 1 shaker under each recliner.


I assume I would split my LFE signal with a Y-connector and then go 1) to my Sub and 2) to the amp.


My question is, what type of amp do I need? Are there amps that would allow me to power 7-25w shakers or would I need 2? Can someone provide me a link to a cost effective amp solution?


Thanks


Jeff
 

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Quote:
Originally posted by jeffczyz
I'll through this into the mix, as I'm considering the bass shakers as well, but am totally clueless on how do set this up. I'll look for everyone's expertise on what I need to do.


I'll have 7 recliners. I would like to put 1 shaker under each recliner.


I assume I would split my LFE signal with a Y-connector and then go 1) to my Sub and 2) to the amp.


My question is, what type of amp do I need? Are there amps that would allow me to power 7-25w shakers or would I need 2? Can someone provide me a link to a cost effective amp solution?


Thanks


Jeff


The most crucial part of wiring 7 Auras is to get the impedance correct. Wiring them all in parallel would be devastating to almost any amp (nominally 0.57 ohms!). Running them all in series would present a nominal impedance of 28 ohms - just hard to drive.


You would need to run them in combinations of series and parallel so that you net an acceptable nominal impedance. You also have to have relatively 'uniform' current flow through each shaker.


There are two possible solutions as I see them to yield the closest to 4 ohms as possible, which is ideal for sub amps.


The first is to run one set of 3 in series (12 ohms) and one set of 4 in series (16 ohms), then run these sets in parallel to yield a nominal 6.9 ohm load. This is also the most uniform in terms of current flow per shaker (meaning most uniform power output).


The second option is to run two sets of 2 in series (8 ohms each) and a set of 3 in series (12 ohms). Then these 3 sets in parallel yielding a nominal 3 ohm load. There is a slightly larger difference in the current flow through the set of 3 vs the sets of 2.


Then the best amplifier solution BY FAR would probably be the 250W subwoofer amp from PE (#300-794). I have a friend who uses the 120W version (300-792) for 4 of the Auras with great results. 7 Auras would need more juice.


The major benefit as has been stated before is that you have far better control with these amps due to a local low pass filter and local gain control. My friend uses 45-50Hz to the Auras while his sub out that feeds it (and his real subs) is at 80Hz. You also have the option of turning the amp off for music if you so desire.


Good luck!


- Dieter
 

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That is all greek to me. I just ordered the 4-pairs of bass shakers(25w) from PE. As far as Ohms etc, I'm lost. Wiring in Parallel vs. in a series. Even more confusing.


Somehow I was under the assumption I would have 7 wires run directly from seperate connections on an amp to each bass shaker.


Let me see if I understand this though.


For my set of 4, I would have 1 wire pair(+/-) coming from the amp. I would then split that wire to each of the shakers.


Or I could have 1 wire, wired to shaker 1, from shaker 1 jump to shaker 2 to shaker 3 to shaker 4... something like that?


I just like to watch movies.. didn't know I had to be an engineer for this stuff
 

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Quote:
Originally posted by jeffczyz
That is all greek to me. I just ordered the 4-pairs of bass shakers(25w) from PE. As far as Ohms etc, I'm lost. Wiring in Parallel vs. in a series. Even more confusing.


Somehow I was under the assumption I would have 7 wires run directly from seperate connections on an amp to each bass shaker.


Let me see if I understand this though.


For my set of 4, I would have 1 wire pair(+/-) coming from the amp. I would then split that wire to each of the shakers.


Or I could have 1 wire, wired to shaker 1, from shaker 1 jump to shaker 2 to shaker 3 to shaker 4... something like that?


I just like to watch movies.. didn't know I had to be an engineer for this stuff


I understand your confusion! There is a huge danger in hooking this many (or any speaker) up 'wrong'.


I am trying to draw a diagram to post a picture of each scenario. What you describe first is essentially wiring all the Auras in parallel yielding the 0.57 ohm Amp-fryer impedance. The second way you describe I -think- is the all in series scenario I described with the 28 ohm impedance.


I will post when I have them.


- DIeter
 

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Here's the first way (the 6.9 ohm version).


Note that the dashed lines are 'equivalent' to the solid lines, as it may make the hookup easier. What is important is the daisy-chaining (series) of the Auras, and then the linking of these across the +/- wires (parallel).


The sub amplifier will have ONE pair of wires coming out of it (+/-). The speaker wire binding posts on the connector side ARE NOT the outputs from the internal amp. Also, the Auras have a gold and silver wire. I don't recall if the instructions say which is which, but just so long as you're consistent....


I would strongly suggest sketching your chair layout and coming up with a wiring pattern that's the 'same' as one of these pictures. The Auras come with male flat crimp-on connectors and standard zip-cord speaker wire. Nothing special.


- Dieter
 

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Thanks. I think that makes more sense. WHat if my amp is a 2 channel amp? Can I break up 1 set from the other?
 

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Quote:
Originally posted by jeffczyz
Thanks. I think that makes more sense. WHat if my amp is a 2 channel amp? Can I break up 1 set from the other?
I assume you mean a stereo amp. The answer is yes, but again, you would likely wire one channel with 3 Auras in series (daisy chained) and the other with 4 in series. This would make 12 ohms on one channel and 16 on the other. If the amp has at least 100WPC, it would work, otherwise it may not drive them hard enough. You also have to make sure they only get 80HZ or less. The alternative is to wire two parallel pairs in series (netting 4 ohms) on one channel, and then running a pair in series and then that in parallel with a single (netting 2.7 ohms). This is getting a bit low for most run-of-the-mill amps to handle. If you were wiring 8 auras, you would wire two parallel pairs in series, netting 4 ohms per set of 4.


I am still having problems uploading the other picture... Server error.


- Dieter
 

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Discussion Starter · #18 ·
XP, so it is negative to positive from A1 to A2?...I am only hooking up two Aura's to start...thanks! :confused:
 

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Quote:
Originally posted by davy2
XP, so it is negative to positive from A1 to A2?...I am only hooking up two Aura's to start...thanks! :confused:
Yes, that puts them in series - netting 8 ohms. A very safe load for an amp.


- Dieter
 

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Quote:
Originally posted by xp800


I am still having problems uploading the other picture... Server error.
Let's try this again. This is the '3 way' version that nets 3 ohms overall.


You can figure these circuits out for yourself with a bit of 'figgerin.


Series resistance/impedance (daisy chained) is:


Rtotal = R1 +R1 + Rn


You just add up all the numbers to get a total.


Parallel is a bit more mathish:


1/Rtotal = 1/R1 + 1/R2 + 1/Rn


In the example of the 3 ohm overall '3 leg' version:


leg 1 series: R = 4+4 = 8 ohms

leg 2 series: R = 4+4 = 8 ohms

leg 3 series: R = 4+4+4 = 12 ohms


Then legs 1,2,3 in parallel:


1/Rtotal = 1/8 + 1/8 + 1/12 = 1/3


So Rtotal = 3 ohms


- Dieter
 
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