Adding bass shakers to an HTiB... (1 Viewer)

[David Lawson]

This will be something of a rehash from a few months ago, and is really more of a connection/cabling issue at this point since I have all of the necessary equipment (I think).
I'm looking for the best way to run both a subwoofer and an old stereo receiver (being used only as an amplifier for the bass shakers) from the lone subwoofer output on my Kenwood VR-517. In the above linked thread, Guy suggests a "Y adapter" as a solution, something I might have to fashion myself since the subwoofer and the stereo receiver use different types of plugs.
The setup that I detailed near the end of that thread is still the setup I have at this point, with the stereo receiver connected to the DVD player with composite (red and white) audio cables. The subwoofer is connected to the VR-517 via its spring terminals. Is it possible to combine these two types of connectors into one "Y adapter", or do I even need to do such a thing?
My knowledge of wattage and impedance is also limited, and I'm concerned about running both pieces of equipment from the same output. The sub output is rated at 100 watts, as is the subwoofer itself. The bass shakers are rated at 25 watts each, so does that mean I would be up to 150 total watts? Will I even approach the 100 watts "limit" if I keep the volume low? I rarely have the system above -40 dB (according to the VR-517) since I'm in an apartment.
Any suggestions on how to make a "Y adapter" and/or explanations on wattage would be appreciated.

 

[Dave Poehlman]

I would think your Kenwood would have an RCA jack type output for the sub. And your old receiver should have RCA type inputs for it's components.

You should be able to just split the low level output on the Kenwood to the input on the sub and one of the component inputs on the old amp. (ie: VCR, CD, etc... don't use the phono input) You may have to split it again to the right and left channels (one for each bass shaker I am assuming)

Or, better yet, if your sub has an output on it, you could just "chain" them together. (Kenwood to sub to old amp to bass shakers)

As far as the wattage.. the 100 Watts on the sub amp is just telling you how much power the sub amp is capable of. The 25 Watt rating on the bass shakers is telling you how much they can handle. Provided you don't crank the volume on the old amp powering the shakers, you should have no problem.

 

[David Lawson]

Unfortunately, the VR-517 has no RCA outputs for any of the speakers or subwoofer. Some of the other VR-5XX series have a subwoofer pre out, but not this one. The subwoofer itself has no outputs on it, either.
Thanks for the clarification on the wattage. Any additional suggestions?

 

[Mark O'Donnell]

what you are asking is a bit more complicated.

What you are interested in is the ohm load when wiring your speakers. This can be very harmful to your reciever.

If you wire in series 2 8 ohm speakers you now have a 16 ohm load.

If you wire the same 8 ohm speakers in parallel you have a now reduced you load to 4 ohms.

You need to check your amps load rating first.

The wiring you can do yourself. You can get cheap wires and modify (cut, split, solder) yourself.

Credit to AVS Movie Mike for this info:

Wiring SERIES

For the left side:

The black terminal on the back of your amp is connected to the black terminal on the back of the first speaker. The red terminal on the first speaker is connected to the black terminal on the second speaker. Finally the red terminal on the back of the second speaker is connected to the red terminal on the back of your amp. (It makes a big loop.)

Repeat for the right side.

Wiring PARALLEL

For the left side:

The black terminal on the amp connects to the black terminal on the first speaker. Run a second wire from the black terminal on the amp to the black terminal on the second speaker.

Repeat for the reds. (The black and red wires run parallel to each other.)

Repeat for the right side.

Hope this helps.

Oh yeah you can also invest some money in a good speaker selector. This will provide your reciever with the needed security allowing you to chose 1,2,3 or all speakers running from one output source. (check Circut City they have a good one for about $70.00)

 

[David Lawson]

Mark -

Regarding the speaker selector, would it be possible to attach both the subwoofer and the bass shakers to it, bypassing the second receiver altogether? I realize that I'm suddenly back to dealing with 150 watts on a 100 watt channel, but since I don't crank the volume by any stretch, I might be okay.

I do have a question about the ohm load on a speaker selector, since I notice most of them are capable of sending the same sound signal to all of the speaker sets attached to them. Does the selector have something to compensate for a multiple ohm load from what (in my case) would be two sets of speakers being driven at once, or does it not work that way? Would both the subwoofer and the bass shakers need to have the same impedance? The subwoofer is 8 ohms, and the bass shakers are 4 ohms, but I could wire the shakers in series to get 8 ohms.

Thanks in advance.

 

[Jason_RoyH]

From the car audio world comes a little device that takes speaker lvl and turns it into preamp line-level. Its made for installing a sub amp while using the stock rear speakers wire as the signal input. The stock rear speakers play normally while the converter gives you a line-level signal. So in this case you could use the level converter, a cheap 12v power supply, and a seperate amp for the bass shakers.

So you hook the converter to the subs speaker lvl wire. Use an rca y adapter (all 3 males)to take that single channel output into a dual mono input. Plug that into the other amp. Use that amps speaker outputs to drive the bass shakers.

 

[Mark O'Donnell]

In response to your first question.

I do not feel that both the subwoofer and the bass shakers would be harmful to your reciever when connected to a good speaker selector. Most are rated at 100 watts. The load on your LFE channels would not be that great especially for movies.

Now the second question.

Does the selector have something to compensate for a multiple ohm load from what (in my case) would be two sets of speakers being driven at once, or does it not work that way?

Yes it does. This is it's primary purpose. It should be able to handle 4,6,or 8ohm speakers mixed, and send the reciever a load within limits.

Example:

4 pairs of 8 ohm speakers wired to a good speaker selector will send a reciever a 4.5 ohm load when all 8 speakers are selected.

Make sure if you pick a speaker selector that you go with a brand that has protection.

Monster Cable is the brand that I purchased at CC but there is also Niles brand and Sima (Although I would not purchase Sima. The price reflects low wattage)

Hope this helps.

Mark OD.

 

[David Lawson]

Mark -
I noticed the same Monster Cable selector at Circuit City, but neither MC's nor CC's Web site has much information on the device. You mentioned that a good selector should be able to handle mixed ohm loads. Does the Monster? I'll admit that I only ask this out of laziness, as I don't really feel like crawling under the couch and rewiring the shakers in series.
If it does, I think I might go ahead and purchase it. I have a few CC gift cards to use up, anyway.
Jason -
Thanks for the idea, but Mark's suggestion seems to be the easiest, at least for someone like me.

 

[Mark O'Donnell]

Give me a couple hours.

When I get home I will get the box out with the exact info you want.

 

[David Lawson]

Thanks. I suppose I can put the purchase off until tomorrow.

 

[Mark O'Donnell]

Ok David.
It's a Monster Cable 4 way speaker selector.
Rated as protecting up to 8 ohms and 150 watts. (sounds like what you are looking for)
It's in a purple box.
The design is pretty hefty. All metal black housing so it weighs about 5 lbs and its pretty small for what it does.
There is an input for your source and 4 seperate outputs for speakers pairs. On the front there are 4 round buttons for selecting the speakers and one round button for activiating the protection when using more than one pair of speakers.
That's it... CC should still be open.

 

[David Lawson]

Thanks, Mark!

 

[David Lawson]

I suppose I should have asked this earlier...

The Monster Cable speaker selector is expecting pairs of speakers, since it has both L and R inputs from the amplifier and outputs for the speakers. I'm not dealing with L and R inputs or outputs, though...the subwoofer out on my receiver has only one set of connectors, as does the subwoofer itself.

How should I connect the subwoofer, bass shakers, and receiver to the speaker selector? I initially hooked everything up to the L connectors, but that gave me almost no output whatsoever (I can barely feel some rumbling in the shakers, if I put my hands on top of them). The subwoofer channel has also been turned to its maximum "loudness" (+10 dB on the Kenwood), so I'm not sure I can make it any louder.

Was this the correct way to hook everything up, or will I need to somehow "fool" the speaker selector into thinking that it's receiving L and R inputs?

 

[Chuck_C]

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I'm looking for the best way to run both a subwoofer and an old stereo receiver (being used only as an amplifier for the bass shakers) from the lone subwoofer output on my Kenwood VR-517. In the above linked thread, Guy suggests a "Y adapter" as a solution, something I might have to fashion myself since the subwoofer and the stereo receiver use different types of plugs.

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I just hooked up my bass shakers last week using an old stereo receiver. I had a extra pass through LF outlet on my subwoofer that I ran to my auxiliary input on the old receiver (using just one channel). I connected the two shakers in series to get their 4 ohm rating to the receiver’s 8 ohm requirement. The receiver rates at 125 watts per channel and the shakers are each 25 watts for a total of 50 watts. I have the volume control on the receiver at about 1/3 or so. This setup works great without getting spending any extra $$. You could do the same by constructing that special ‘Y’ cable you need to hook up to your subwoofer output on your Kenwood.