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Poor In-Ceiling Setup - What to do?

 

New member
Username: Commandodad

Post Number: 1
Registered: Jun-13
Hi everyone. I joined this forum because I need some help.

My wife & I bought a house a few years ago. The house has 6 in-ceiling speakers (8 ohm Realistic [from RadioShack]) that are wired together.

I can't see how these are wired together because there is no access to the area in the house except for ripping off the roof or cutting a bunch holes in the ceiling.

Using an Ohm meter, I received a reading of 1.1 ohms. Assuming these 6 speakers were connected in a parallel circuit, that would result total of 8 ohm/6 speakers = 4/3 = 1.333 ohm. So, I think the reading matches with the theoretical configuration.

I have a 100W x 2 Insignia NS-R2000 receiver that States Channel A OR B, minimum 8 ohm; Channel A+B minimum 16 ohm.

With that configuration I have two concerns.

First, and most important, is that I don't want to blow out my receiver. I had one blow out when I turned the volume up beyond half...I assume it happened as a result of the parallel configuration. I was thinking of using a little project box to put 8 to 16 ohms of resistance in series to throttle the power. Is that a good option? Does anyone have other suggestions?

Second, with only 1 set of speaker wire coming out of the ceiling for these speakers I think I can't hear songs that need left/right sound. Besides hooking up new speakers or ripping into my house to rewire these speakers, does anyone have suggestions?

I really appreciate the assistance!
 

Gold Member
Username: Superjazzyjames

Post Number: 2239
Registered: Oct-10
I would recommend getting a pair of floor speakers or book shelf speakers and subwoofer and not even bothering with the in ceiling speakers. If it's at all possible, you may want to pull those speakers out and patch up the holes.

You are correct that the speakers were shorting out your other receiver. Most receivers on the market today claim to be stable down to 4 ohms. 1.1 is NOT what you want to subject your receiver to.
 

Platinum Member
Username: Jan_b_vigne

Dallas, TX

Post Number: 17776
Registered: May-04
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You are making assumptions which are not truly verified by your meter only measurements. Only a fool would wire six speakers in parallel thereby dropping the resistance - not "impedance" - down to one Ohm. Now, I'm not saying there aren't plenty of fools out there who would do just that, but it would take a significantly intense fool to do so. But your measurement of resistance could just as easily be nothing more than the length of cabling in the walls.

Are there any volume controls for these speakers? If so, you would want to examine the type of control being used. This could also account for your low resistance measurement.

It appears you have only a "+" and a "-" connection for all of these speakers? I'd once again say only a fool ... Who would wire a mono system today? And, for what purpose? Answer that and you might find the answer to several other of your questions.


I'm guessing you have no idea who would have performed the installation of such a system. Certainly, if you knew, you could contact them and have some questions answered. Radio Shack speakers aren't the normal fare for most audio installers who normally have a contact to purchase equipment at a reduced price.

Was this a new home when you moved in? If so, then the contractor/builder should have some information you could use. I've seen hundreds of audio installs done as a package by the same company wiring the alarm systems and the garbage disposal. Occasionally the builder will go to an actual audio retailer for their equipment, not often since "cheap installers" work cheap and provide higher profit while pushing off problems on the buyer. Some retailers have their own crews who do their pre-wires and re-wires, others subcontract the work out to vagabonds and gypsies at the back door. Very few of them at all do I trust to do the work correctly. One day you're a travelling minstral wandering the Earth in search of your next meal, the next you're the most seasoned audio installer in the group of installers packed into the van. Unfortunately, I've seen this very thing happen. This was a particularly bad problem when houses were going up in a few days time to meet the demand for sub-prime mortgages being pushed on unsuspecting buyers. Cheap begot cheap which gave birth to so many headaches for the buyers it's no wonder many just walked away. Your home wouldn't also be plagued by poltergeist, would it?


There is no way for you to turn a single leg of cable into a stereo configuration, unless you are also skilled with fishes and loaves. If you have no way to contact the person who might have done the install - and you still really want to use ceiling speakers, your best bet is to contact a local audio retailer/installer. During the boom days of house sales a few years back, many retailers and installers were kept busy every day doing pre-wires for builders and contractors along with new home buyers retro-fitting existing structures. Any qualified installer can tell you what is likely to exist in your walls. They will have more equipment than an Ohm meter to do their search. They can use the existing cabling in most instances as pull wires for a new wiring lay out which will better serve your needs. And they can suggest equipment which will allow better utilization of your present and future equipment.



"First, and most important, is that I don't want to blow out my receiver. I had one blow out when I turned the volume up beyond half...I assume it happened as a result of the parallel configuration."


Since I'm not convinced your speakers are wired in parallel, I'll give you as much as saying the amp blew up due to the load it was presented. However, more than anything I would wager the receiver blew up due to the amount of wattage you were asking of it into a load of six speakers and insufficient protection and heat sinking in a budget line product. High wattage produces heat and heat destroys electronics. Most amplifiers/receivers reach full power at approximately half way on the dial. Asking more than that will send the amplifier into clipping which will easily destroy inexpensive gear.



Since this event, have you verified that each speaker is still operational? Once again a dead voice coil or two and the cable runs could have easily provided your meter reading. Hooking a receiver up to a dead voice coil could once again destroy your receiver. I think you are assuming too much when all you've done is a rudimentary check. I understand there's not much more you can do in this situation. That's why a qualified installer should be able to get you through. Check with your local audio retailers or contact one of the builders in your area to get a recommendation.




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Gold Member
Username: Superjazzyjames

Post Number: 2240
Registered: Oct-10
Jan, I don't know if you've gone back to the "Building A Powerful Home System" thread, but Leo and I both posted possible solutions to your pop-up ad problem in case you haven't resolved it already.
 

New member
Username: Commandodad

Post Number: 2
Registered: Jun-13
The problem is that the former homeowner did do a lot of things wrong in the house. I'm learning to assume things are wrong---like wiring 6, 8-ohm speakers in parallel.

The question is: can I simply add a resistor or something else in series to keep the amp from overloading?
 

Platinum Member
Username: Jan_b_vigne

Dallas, TX

Post Number: 17777
Registered: May-04
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Did'ja ever see the "Beverly Hills Cop" movie with Eddie Murphy where he shoved a banana into the tail pipe of the car he's trailing? Car won't start because it can't exhaust the spent fuel gasses. That was a clever bit of writing making use of what the characters might have had available.


Sticking another resistor in line with what's in your ceiling? Not so much.




No, if you are unclear on what is actually in the ceiling, you cannot just begin to add more crap on top of the system without thinking just like the prior home owner. I assume you didn't bother to read my prior post.

Tell me you've had someone with more equipment and experience come in to fully and properly wring out the system and give you a suggestion for how to proceed and then I'll give you my opinion of where to go with this. But I'm not inclined to tell anyone to add stupid on top of stupid.

From what you've posted this is not a fully operational system on several counts. If you can't look forward and foresee the numerous problems with your proposal, then you're not the person to try "fixing" what someone else boogered up. You need a decently configured system rather than a system that's just forced to do something you won't like anyway.



Sorry if you're offended but I've been called in to "fix" what too many "brilliant" people have done after assuming they knew how things worked for me to add to the problem for some installer in your area.

Get a professional involved and spend the money to do the job correctly. Or blow off using these speakers all together. Take them out and patch the holes. Start over from scratch with good speakers and a good install. With the great numbers of people over the last decade wanting their homes wired for sound there's very little that cannot be accomplished in most homes. A qualified installer can give you multiple options for this set up.

Even with a jerry rigged patch to raise the impedance - a resistor is not the "patch" I'm talking about - you would still have a mono system if what you assume about the wiring is true. What are you going to do with a mono system? Add another six speakers that don't match what's already there? Run only one channel of your receiver into these speakers for a half way stereo system? Really?! That's a "plan"?



C'mon, guy. Think this through a bit. There are at least another half dozen things I can see you haven't thought about. But you want to just add a resistor?



You have some access to wires. You're best bet at this moment, knowing no more than you do after using your DVM, is to use those wires as pull lines for a new, correct wiring scheme. There are other options a decent installer can suggest. But you'll have to obtain a better idea of what's actually in the ceiling before you even do that. That's what a qualified installer can tell you.

Look, you either need to have a workable plan or you need to just forget about these speakers. They're not very good to begin with.





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