Has anyone ever head of a speaker selector switch overheating?

[cbolton]

Hello,

I hope someone has some ideas here - I have been trying to fix this since 10AM and no luck so far.

I just purchased and have a Denon 2105 L/R "Zone 2" connected to receiver L/R connections on a Niles HDL-4 speaker switcher. On the speaker switch I have the wire with 4 connections (Green, White, Red, Black) plugged into L/R on "speaker selection 1" on the HDL-4(our home came prewired with speakers in select rooms with a volume knob on the wall).

I am now getting multisource audio: Family Room playing 5.1 DVD and CD audio on the other speakers plugged into speaker switch above. My problem now is heat - the HDL-4 gets extremely hot within 5 minutes of turning on Zone2 audio. It began to smell like something was burning/getting hot in the HDL4 so I immediately turned Zone2 off. I have doublechecked all speaker connections and have not reversed any of the wires. The HDL-4 mentions it must be connected to a receiver that supports a 4 ohm speaker. The 2105 specs:

7 Channels equal power amplifier section • 90 watts per channel (8 ohms, 20 Hz-20 kHz, <.05%THD) • 125 watts per channel (6 ohms, 1 kHz, <.7%THD)

I wonder if the power from the receiver is too much for the switch to handle? Here are the speakers connected to the switcher:

6xSonance Cr100 5-25watt speakers(2 in MBed, 2 in Patio, 2 in Den)
1xSonance 621SSTR 5-50 watt speakers(in MBath)

The above speakers all sound great with the audio going in Zone2...

This is not looking good - I believe that I left the Zone2 on it would at the very least fry the speaker switcher. I want to UE and informed them of the overheat problem - I was very skeptical when they mentioned that the HDL must have "gone bad" so they sold me a Monster speaker switcher to try it - well same problem exists with it overheating in 5 mins. Is it possible that I somehow(even after checking) have something wired incorrectly causing the heat issue? If I don't get this worked out I'll be returning the receiver - the only reason I bought it was for multisource audio...

Any ideas? Your input would be greatly appreciated.

Craig

 

[Unregistered]

My guess would be that the in-wall speakers are wired in parallel and thus the combined impdeance is too low for the amp to drive easily.

 

[cbolton]

That makes sense but?

My guess would be that the in-wall speakers are wired in parallel and thus the combined impdeance is too low for the amp to drive easily.

Before buying the new receiver I had a similar configuration with the speaker switch connected to the "B" speakers posts on my old Yamaha RX-V1000 5.1 receiver. The only difference I can see with the new setup is that the Denon 2105 is a 7.1 receiver and the 6/7 channels in "Zone2" are now getting full power to the speaker switch and the rest of the speakers.

So it's sounding like the B speaker might be my only option - problem with that is I can't get multisource audio that way

I suppose another option is to go up and rewire all the speakers and not have them wired in parallel. But access to many of these speakers(like the patio especially) is not goign to be easy...

 

[Unregistered]

Just noticed that the HDL-4 requires an amplifier that can handle 4 Ohm speakers. To me this implies that the speaker selector will maintain a constant impedance of 4 Ohms.

From your description it sounds like you have your main 5.1 speakers hooked to the receiver and then the Niles hooked to channels 6/7 (with ALL the in-wall speakers hooked to it). If the impedance of the main speakers is 8 ohm and the Niles is set to maintain a constant impedance of 4 Ohms, your effective impedance is 1/(1/8+1/4) = 2.666 Ohms - a very tough load to drive.

Maybe it worked OK with the Yamaha because it is better suited to handling low impedances. Note that nearly A/B speaker switches on receivers are wired in parallel, so that would be even worse.

The info I found said the Niles is switchable between constant and selectable impedance protection. If set to 'selectable' can you select 8 ohms?

 

[cbolton]

Hi,

The niles in the rear near the amp/speaker inputs has an on/off switch for "constant protection" which is currently set to on. There is also a protection on/off switch on the front of the unit which is normally "on" as well. This is the exact same setup I had on the Yamaha. From what I read - the constant protection is designed to be a failsafe in case someone turns off the protection switch on the front of the unit. There are no other controls/buttons on the unit except the protection button and switch.

I wired zone2 channel six and seven(L/R) to the Niles HDL4 amplifier L/R inputs. I originally wired both the green/white wire and the black/red wire to speaker 1 on the switch - I moved the green/white to speaker 2 on the switch to see if that changed anything - it didn't. I did find out that the green/white runs all L speakers in the house and the red/white runs all the R speakers in the house confirming the parallel wiring theory I believe.

Ultimate Electronics suggested the move of one pair of wires from speaker 1 to 2 and that was their best guess so far.

 

[annunaki]

Let me see if I have this straight. You are using your zone 2 output (channels 6&7) to drive the rest of the speakers in your home through a speaker selector. How many speaker wire pairs are coming from the speakers in your home? There should be 7 if the house was wired properly. If they are all wired in parallel that is the problem.

Let me ask a few questions. Do you have separate volume controls in each room? When you hook up the green/white wires all the left speakers come on at the same time? And the same for the right red/black? If this is the case, you are looking at around a 2 ohm load on each channel. Those switching units are designed to run a bunch of 8 ohm or possibly 4 ohm speakers, not 2 ohms on each channel. If this is indeed the case I would do some serious b****ing at whom ever wired your home.

When I wired homes for customers, they always had volume controls in each room. If not I still would wire the same way. With volume controls you have a home run from each volume control to your electronics location. From the volume control you run to each speaker. Then all the speaker outputs are connected to an impedance matcher (usually from Phoenix Gold as they are one of the only companies that make one). Finally the amplifier's outputs would see a 4 ohm load from the impedance matcher with up to 12 pairs of speakers (24 individual speakers) on it.

Without volume controls you home run from each speaker to the electronics location to use a switcher.Basically the same except the volume controls and impedance matcher are removed.

 

[cbolton]

Hi annunaki,

The Patio, Mbed, Mbath, Den all have audio volume dials. As you indicated below the red/black represent the right speakers and green/white represent the left speakers. The speakers are wired in parallel unfortunately. As the home was purchased used it appears the company who specializes in "custom" home audio/video installs went the cheap route. It's too bad I wasn't involved in building the home because I would have asked about the ramnfications of parallel wiring the speakers...

I came back to UE looking for more information and I guy there suggested I try a Niles SI-245 systems integration amplifier. I removed the speaker switch connections to channels 6/7 Zone2 and I plugged the Zone2 L/R coax outs on the receiver to the amp and the wires from the speaker switch to the L/R speaker posts on the back of the amp. It appears this has solved the issue with the speaker switch heating up - the low ohm and high power from the receiver basically overpowered the speaker switch. The speaker switch is still has some heat to it but I would compare it to the heat output it had with the Yamaha(definitely warm but not scorching hot). The Niles SI-245 is hotter than the switch but not scorching hot as what was happening before. This is a really dumb question but how hot is too hot? I don't smell anything burning up and it's been running for almost 2 hours now...

The other problem now is that the audio in the zone2 speakers is extremely low - with the dials cranked up it's not as loud as I would like. I suspect when I mention this to UE they will suggest I upgrade to the Niles SI-275 which they tried to sell me from the start: It has

75 watts RMS per channel into 8 ohms, both channels driven
100 watts RMS per channel into 4 ohms, both channels driven

vs the 245:

45 watts RMS per channel into 8 ohms, both channels driven
70 watts RMS per channel into 4 ohms, both channels driven

I wonder though if I ugpraded to the higher power it would just make the heat problem above worse and not improve the volume issue?

Thanks a ton for your insightful responses - I am learning a lot through this process.

 

[annunaki]

Running systems in parallel, as in your case, seems to suggest an uneducated installer. Even if the volume controls were impedance matching, it still puts you down to a 2 ohm load per channel. Just be thankful that no other rooms were run onto the parallel circuit.

If you have volume controls in each room you DO NOT need a speaker selector. What you need is an amplifier capable of driving a 2 ohm load on each channel. I would look into an Audio Source amplifier, as they are fairly inexpensive, yet have no problems with low impedances. Your Niles amplifier will work if it is stable into a two ohm stereo load. Getting a bigger amplifier like the step up Niles piece will only gain you a net theoretical 3db with music. Which, by the way, is just barely noticeable by most people. So it may not be worh the upgrade. I am thinking that your partially damaged speaker selector is the cause for your reduced volume.

Find out if your amp will be stable into two ohms (If not get an amplifier that can). Remove the speaker selector. Enjoy your system.

 

[cbolton]

Hi annunaki,

Thanks for your reply... I tried the setup without the speaker switch (black/red, white/green) directly to the Niles amp and the music stutters and the amp "clicks" every few seconds in line with the stuttering.

I suspect the amp can't handle the low impedance from the speakers...

I'll keep messing around with this - I have a 30 day no questions asked return policy on this stuff so I have options if I don't get this resolved to my satisfaction.

I appreciate your insight into the issues here.

Craig

 

[annunaki]

Take the amplifier back now why waste more time, or risk damaging the amplifier? Judging by what you have just described, it CANNOT handle a 2 ohm load. Do some seaching for a stereo amplifier, or pair of mono amplifiers, that will handle a 2 ohm nominal impedance. Remember the low impedances are not from the speakers themselves, but rather from the inexperienced installer who wired them. Basically, it is from how the speakers are wired. Good luck, PM me if you have any specific questions on product.

 

[dreadstar]

Overheat.

Get a OHM meter and check the resistance at the hookup to your amp. disconect the wires of course.

If the resistance is below 4ohms you will need an amplifier that can handle that load. Most of the yamaha line can handle 2/4/8 ohm loads which is why you didn't have the problem.

Also check into the possibility of using another amplifier with your multisource receiver so that it can handle the load and your receiver doesn't have to.