Shakers - Simple/Cheap Hookup - Visual Guide - Page 3

Bob / Anyone:

Set up the Aura's with a splitter at the sub preout. (Aura's connected to Old Kenwood amp.)

When the amp (Kenwood / Aura's) is on, getting a hum on the powered sub. I can turn down the volume on the sub to eliminate the hum, but lose power doing so.

Tried different cables, no splitter, hum is eliminated when running without the shaker amp.

Any ideas on what is happening, or what to try next?

Thanks!

Update:

Tried a dfferent amp on the same setup, still the hum when connected and poweed, different cables, too. Hum is eliminated when not using the split signal, however is only around when the separate shaker amp is powered. which auto starts the sub amp. If the sub amp is off, the hum only appears when the shake amp is powered up. Some type of current is being passed back through the cable, seems to me. Not sure how to eliminate it.

Often when a sub hums it is due to a ground loop problem. More often than not. One way to get around this is to use a "cheater plug" to eliminate the ground prong on your subs AC cord. That is if your sub has a 3 prong plug. The cheater is an adapter that converts a 3 prong into a 2 prong plug. I had to do this with my HSU sub and it removed all traces of hum.

Actually in my case my sub uses a common computer type AC cord, of which I have several of those laying around. I simply cut the ground prong off of one of those cords and viola', no more hum.

The best part is that it is cheap and easy to try.

...and the worst part is that ground is there for safety.

Power devices should NEVER have the grounds removed!

No third prong. KLH 12" sub. Any more ideas?

Thanks!!

I'm not sure where you should go from there. Maybe someone else has another suggestion.

As far as removing the ground, it is more than safe to remove it from a device such as a sub. If it wasn't I'm sure that HSU wouldn't recommend doing so for this very problem. And it worked just fine on my system.

Oh and one more thing, the other Dean, just in case your worried about this too, the sky is not falling either!!

What's your basis for this besides your opinion?

I've been shocked by a floating ground have you? If there is a failure in the amp and 120 is put on the chassis you have a dangerous situation.

HSU's design may be as such that they're willing to take that risk and have convinced others that it's not a problem -- I still stand on my statement.

What's the sky got to do with this?

I think an isolation transformer will solve your problem safely.

Do a search on the web for a stereo version.

The loop in the signal grounds is the real problem.

If all else fails....

Tried another SHIELDED cable, and viola! No hum.

Off to watch LOTR!

THanks for all of the replies. To all, Happy Holidays!

I would say that I base it on the Electronics degree I have but I wouldn't expect you to take my word for it. Like I said before though I have an HSU sub that hummed all the time. By removing the ground prong as per HSU's suggestion it worked fine. I haven't been electrocuted yet.

Now if you were going to be using the sub outside or in a otherwise potentially wet environment then I would definitely NOT recommend removing the ground.

I do have a question for you, Dean. How many pieces of your AV gear has a 3 prong plug? In my system maybe a third do the rest don't. Should I replace the cords on the ones that don't? Might be a shock hazard there?? Of course I wouldn't do that, because it's just not necessary.

Your idea of an isolation transformer is a good one but it may not be the cheapest way to go. The best thing is to track down the guilty component introducing the ground loop and go from there.

Just in case you still doubt the cheater plug idea look in the pdf file below. Chapter 3 in the trouble shooting section. There are some good suggestions on how to track down the problem component there as well.

http://www.hsuresearch.com/vtf2.pdf

Or a quick search found this, second question and answer.

http://www.hometheaterhifi.com/qa/qa9798/qa82.html

Oh yeah, the sky is falling thing was just a joke. You know as in Chicken Little. Some people just worry too much.

Have fun.

Good for you ggingrich I'm glad you tracked it down. And a bit cheaper than an isolation transformer too!

Well, not so fast.

Hum is gone. What happens now is the shaker amp clicks, and nothing happens. Seems to be when LFE is engaged. Going to look for a short, but thought I'd check here to see if someone might have an idea.

Using a Denon 4802, SW pre out connected to splitter, going to KLH 120w sub and Kenwood for the shakers. It was working with the bad cable. Using rg-58 with Radio Shack adapters to get ro RCA from F connects.

Thanks,

Galen

Update:

Once again, fixed it. Cable splice was shorting. Have to pass through the phono input, must have blown the other input. Bottom line, they ROCK.

Happy Holidays!

The point of discussion was a POWER device (i.e. power amp, receiver) not the line level devices (i.e. CD player, EQ, etc.)

Amps/receivers have a third prong for safety because the possibility exists of a dangerous situation during certain component failure scenarios and causing the chassis to become *live*.

Not all do, but my point was the ones that do should not be considered some kind of option for audio tweaking and simply removed. There were designed with ground fault protection for a reason.

If you are an EE I can't believe you're disputing this fact.

Happy Holidays

-Chicken Little

My point being is MY receiver and power amp have NO 3rd prong. MY HSU sub does, or did, have a 3rd prong. I removed it and eliminated the hum. Nuff said. Its been running this way for over a year with absolutly NO porblems.

Did you even look at the pdf file? It is the owners manual for the HSU sub. In the trouble shooting section it says to use a cheater plug if your sub has hum. I don't expect you to believe me but I would think you would take the word of the manufacturer of said sub. In this day of lawsuits I don't think they would recommend bypassing a safety device if it truly wasn't safe. They obviously think of it as an "option". Better to use it if its there but if it's causing problems remove it. In this application that is. Its all just a matter of common sense.

And as an EE I'm not disputing the fact that "some" if not most safety devices shouldn't be bypassed. In the case of the ground plug it should never be removed from devices such as power tools that are held in your hand while in use, or from any kind of device that might be used near or handle water, such as a washing machine. Again just common sense.

In the case of a sub, I never use mine in the bathtub or carry it around the house with me. If you do so with yours then I would not suggest your removing its ground plug.

At any rate, have a nice day. And Merry Christmas to everyone.

I'm just a Wild and Crazy guy

My point being is MY receiver and power amp have NO 3rd prong.

-That's because they were designed with a polarized plug and enough circuit isolation for safety.

MY HSU sub does, or did, have a 3rd prong. I removed it and eliminated the hum. Nuff said. Its been running this way for over a year with absolutly NO porblems.
Did you even look at the pdf file? It is the owners manual for the HSU sub. In the trouble shooting section it says to use a cheater plug if your sub has hum. I don't expect you to believe me but I would think you would take the word of the manufacturer of said sub. In this day of lawsuits I don't think they would recommend bypassing a safety device if it truly wasn't safe. They obviously think of it as an "option". Better to use it if its there but if it's causing problems remove it. In this application that is. Its all just a matter of common sense.

-Well I verified this and you are right but this is the first company I've every seen who's said it's OK to lift the safety ground. That doesn't mean it's a good practice to follow for other equipment. It's more than common sense.

And as an EE I'm not disputing the fact that "some" if not most safety devices shouldn't be bypassed.

- And as a fellow EE with prior experience at a pro audio company I declare what you should say is NEVER unless expressly indicated acceptable by the manufacturer i.e. HSU.

In the case of the ground plug it should never be removed from devices such as power tools that are held in your hand while in use, or from any kind of device that might be used near or handle water, such as a washing machine. Again just common sense.

- Common sense? That would tell me not to cut something off the plug.

In the case of a sub, I never use mine in the bathtub or carry it around the house with me. If you do so with yours then I would not suggest your removing its ground plug.

- What happens when my power amp fails, I go to make an adjustment to the volume and get hit with the voltage that's present on the chassis? It happened to me and I wasn't in the bathtub and it wasn't raining. It happened because some boob thought it was ok to lift the ground.


Merry Christmas
And don't be a boob.

Does anyone have any comments on the difference between the standard version and the pro version? I currently plan on using 2 Pro shakers on my couch and 1 normal shaker per my two chairs.

Wow, this thread got way off track from the Shaker topic originally posted. It happens, I know. There is a hum FAQ by Bill at the beginning of one of the forum sections. It may be the speakers threads.

The Pro models handle twice the power and have external heat sinks and therefore stay a little cooler. The Pros shake more. Have you seen the Watt Butt kickers? They are something else.

OK, one quick question:

I would like to place 4 50w pro-shakers in my sofa.

I understand I can Y connect out of my LFE channel that feeds my existing Sub to another amp to drive the shakers.

However, my question is this: The amp I would like to use is just a power amp (Adcom GFA-555 with 165wper channel). In other words, it doesn't have level control. Would I be able to use this, or would have have to use another control amp as well? I would think I would be ok just using the power amp.

Any responsed would be appreciated.

Thanks,

Chris

The Adcom would work great. You would get master volume control by using a passive control device like this:

Thanks HTguy! Ordered 4 pro's this morning. Tech support there was great.

You are welcome. Yes, Parts Express has great support. You do not need the device above, but it would control the output of the Shakers (it would protect them). You could go to a local car audio shop and get a cheap in-line RCA attenuator by Alpine, or another brand that would do the same thing.

Well I got my four shakers yesterday: 2 standard and 2 pro. I mounted them and hooked them up to a pioneer receiver (it is a 5 channel one where the DD decoder has died, but it has a 5 channel in) It is rated down to 6ohm, but I only paid $10 so I have no problem pushing it

I watched 'Black Hawk Down' and 'Twister' All I can say is

Glad they turned out, and they were $1000 cheapter than "Buttkickers".

Glad to hear they're working too.

I received my 4 pro's yesterday and mounted them. They're alright, but probably not mounted to the best seating arrangement.

They're mounted to a double reclining sofa that has plenty of padding, so it dampens the shaker effect. I have all 4 mounted to solid wood on the frame, but there still seems to be too much damping.

Anybody else have this problem?

After reading this thread I ordered a set of two 50 watt Aura Pro Bass Shakers from Parts Express. I just received my Bass Shakers this morning and after opening the box I discovered that someone had messed up the order and send me two pairs of the regular 25 watt Aura Bass shakers. So instead of having two 50 watt bass shakers I have four 25 watt shakers. Now what? I just saved 10 bucks but is this a good thing? I want to shake two seats on my Lazyboy couch so I could mount two 25 watt shakers on each seat. Would that be better than one 50 watt shaker on each seat? What about the power handling ability of the lesser 25 watt shakers. Is that a problem? I want to power them with a Parts Express 250 Watt Subwoofer Amplifier. Will I fry em? These buggers are heavy and I hate to go through the extra expense of sending them back.

Lurker, it is common to lose some vibration due to the materials in the sofa. You may want to take some of the polyfill out and more importantly, mount them on a piece of solid hardwood and experiment re-locating them for highest impact. Lower ribs/back mount and under the seat are most common.

Schuro, PE has never messed up for me, but mistakes can happen. Since it is their mistake don't settle for the ones you received, go for the pros for best impact. PE will have FedEx give you a tracking number and schedule a FedEx Express (demand express, not ground since they dropped the ball) pickup at your door, or business.

I ordered 8 Aura Pro Bass Shakers which arrived the very next day from Parts Express. I would like to put 4 in the back couch and 4 in the front couch. I tried to use a new 6.1 receiver (KLH from best Buy for $150 on sale - I thought that a total of 500 watts was pretty good and if I got tired of the shakers I would have a budget 6.1 receiver for my next project. ) I tried using 2 in series from each of the 2 fronts and each of the 2 surrounds but couldn't get most of them to work very well. Not sure why it didn't work. I tried it several ways but only the center channel seemed to work. I tried different inputs (CD, tape vcr, etc.) but I suspect the amp just wasn't made to send out 4 like signals, always decoding or something. I guess I will give up on this idea and buy the PE 250 watt sub amp since it has remote volume control, crossover, no decoding to get in the way and is about the same price. I know how to wire two shakers each in series but to have all 8 going into a mono amp I am not sure how to do it and keep it at 8 ohms (correct that, 4 ohms). I have heard you can do shakers in series in sets of two and then do each 2 shaker set in parallel with the others and keep to 4 ohms but I just can't picture it. If anyone could tell me how in detail or fax me a diagram, (614) 876-2885 (no cover needed) I would be forever grateful. Thank you for your help. I would love to get this project moving so I can enjoy them.

How are you hooking your subout into the KLH receiver? Are you using the 5.1 in?

__________________
Getting a CRT projector is like heaven. I want to go there, I'm just am not a big fan of the shipping terms.

Man Mike is that wisdom. My old Barco weighed 190 lbs

Splitting sub line from the receiver sub out with a y splitter, one line to the sub and other line to the new receiver, using a Y splitter to run it into the L and R inputs, using the VCR input now. From there I have two shakers run in series attached to each of the front right, front left and center channels for a total of 6 shakers. I have two more shakers to hook up but since I couldn't get these all too work properly, only the center really shakes, I haven't bothered with the other two. I tried various inputs and modes with no improvement. I will check to make sure I have the speakers set for large with no subwoofer just in case I didn't do that. I can't think of anything else.

"I will check to make sure I have the speakers set for large with no sub woofer just in case I didn't do that. I can't think of anything else". (Troy)

Troy, I would set your sat's to "small" to avoid distortion. Set the sub to "on" if you use a conventional sub woofer. Bass Management is not implemented in your receiver unless you do both of those things.

I would use an AUX out on your DVD player and a 100HZ PFMOD passive crossover for the Shakers.