Speaker- Receiver Overheat/Impedance issue

[delaneybob]

Hi All,
I purchased a home about 2 years ago and bought a Marantz 1607 receiver to drive the home theater system. All was well until the receiver tripped one day . I sent it back to marantz for warranty repair and they could not find anything wrong. i did the troubleshooting steps prior to sending and I smelled that transformer resin smell when it tripped. So I purchased a 1608 (despite the 1607 still working). I also purchased an in cabin ventilation unit that keeps the temp <85F and I made sure it had enough exhaust clearance to operate properly. I read many articles saying to keep electronics <85 or the life expectancy really starts to decline.

Well, the 1608 also tripped in a couple months but came back with no transformer smell. I do not crank the volume when the tripping happened either time (1607 or 1608). just normal volume. I disconnected the outdoor speakers and wanted to see if it tripped again. It did after a couple months so I decided to roll the sleeves up and see what's up.

I found that the interior speakers were 6 ohm and the exterior 4 ohm. The interior speakers were original so I replaced those with Polk RC65 8 ohm. All good so far. Now here's where I am adrift and need help

- One outdoor speaker is 4 ohms (fluked the wires disconnected from receiver)
- The other outdoor speaker flukes at 6 ohm- even though they look the same

I ordered Polk Atrium 5 8 ohm speakers to replace them. I may be overspending but I am trying to eliminate causes of the tripping. I have read many articles on mixing different impedance and all say it's ok just leave the impedance on the stereo at 8 ohms which it is. The speakers in my house did need replacement (likely over 15 years old). So I am investing in new speakers all at 8 ohm which likely needed replacement anyways in hopes to eliminate the tripping.

Thoughts please!

I also go ballroom dancing. I mentioned the above to one of the instructors and he said they had same issue with amplifier tripping on the ceiling speakers in the studio so they are using floor speakers. He also said they were 6 ohm ceiling speakers. They are not using the ceiling speakers at all today so my hope is to find out what the deal is and help them too!

Appreciate all your thoughts and help in advance

 

[delaneybob]

Apologizes first unit was a 1606 then went to 1607

 

[everettT]

How long is the run to the outdoor speakers? Does it shutdown when trying to play both at the same time or either or? Where is the AVR placed? Does it have sufficient air flow? Possible the wire gauge isn't sufficient, wire could be damaged for the outdoors and indoors. Also those slim line AVRs are nice for their size but not a power house to run certain setups. As for the ohms, it's it a constant as it changes over their frequency range. So if they dip to 4ohms in a critical area, the Marantz probably doesn't like seeing that.

 

[delaneybob]

Hi thanks for the reply
- It will shutdown (sporadically) when all speakers are connected and only when Indoors are connected
- I do not - well rarely ever crank the volume up - but that is not when i see the trips/shutdowns
The speaker wire is thick- not sure of the gauge but I have to twist it perfect to get it to fit int he holes in the back lugs in the reciever
- I am having a hard time understanding your last sentence- please elaborate

Thanks!

 

[TechHDS]

umm..speakers all over a house, with long speaker runs and you did say that yoy believe the speakers where 15 years old. Since you replaced the ceiling drivers with new ones. What about maybe looking at the long speaker wires up in the ceiling? One could be pinched? or maybe a rat ate into one? I agree with everettT, your unit is a good one but yeah it's not a power house for sure. After you replaced all the driver's I would look at All the wire runs to each speakers you may be surprise what you might find. The are old speaker wires up in the attic, heat over time will get to any wire over time causing them become frail and brittle.

 

[everettT]

Hi thanks for the reply
- It will shutdown (sporadically) when all speakers are connected and only when Indoors are connected
- I do not - well rarely ever crank the volume up - but that is not when i see the trips/shutdowns
The speaker wire is thick- not sure of the gauge but I have to twist it perfect to get it to fit int he holes in the back lugs in the reciever
- I am having a hard time understanding your last sentence- please elaborate

Thanks!

A speaker is rated a nominal ohm, but in reality it varies over its frequency response. So if the speaker is 6ohm @ 2000khz it could very well be 4ohm at 150hz. The slim line Marantz AVRs do not like 4ohm speaker loads when you turn it up, especially when your using all the speakers at once. I'd recommend a beefier AVR, or get a separate amp for the outdoor speakers.

 

[delaneybob]

Ok thanks for all the input. How would I connect the amp

Would it be 1607 AVR--------AMP--------Outdoor speakers? I assume I need 4 input (+ - for each speaker) and 4 output

 

[delaneybob]

Also I have not traced the wires- but there are in the attic and I am in Florida. I would try to do the pulls myself by typing the ends on but I think I will
- Install the new outdoor speakers
- see what happens
- Use an amp if needed
- last thing- replace wires

How's that sound?- pardon the pun

 

[everettT]

Ok thanks for all the input. How would I connect the amp

Would it be 1607 AVR--------AMP--------Outdoor speakers? I assume I need 4 input (+ - for each speaker) and 4 output

Your amp has a zone two preoutput so Connect the amp to that then depending on the total number of outdoor speakers add an impedance matching speaker selector and choose an amp with enough power, ie crown audio xls, xli series

 

[delaneybob]

Ok thanks- if I have 2 speakers for the Amp and the Amp is rated for 4 ohms but the speakers are 8 ohms, is the internals in the Amp seeing the speakers in parallel so it really sees 4 ohm impedance? Or do I need to find an amp rated at 8ohms (assuming the rating is per pair of outputs)

 

[everettT]

Ok thanks- if I have 2 speakers for the Amp and the Amp is rated for 4 ohms but the speakers are 8 ohms, is the internals in the Amp seeing the speakers in parallel so it really sees 4 ohm impedance? Or do I need to find an amp rated at 8ohms (assuming the rating is per pair of outputs)

The crown amps a stable into very low impedance so no issues. If you only have 2 speakers then your fine, if you add more then add the impedance matching speaker selector.

 

[delaneybob]

Ok thanks but Crown amps are $$$$$ it's $230 for a 300W amp. Is there another recommendation? I was looking at this https://www.amazon.com/Channel-Audio-Amplifier-Speakers-TPA3116/dp/B06XZL2PQD/ref=sr_1_2_sspa?s=electronics&ie=UTF8&qid=1516627992&sr=1-2-spons&keywords=50W+amplifier+8+ohms&psc=1

 

[everettT]

Ok thanks but Crown amps are $$$$$ it's $230 for a 300W amp. Is there another recommendation? I was looking at this https://www.amazon.com/Channel-Audio-Amplifier-Speakers-TPA3116/dp/B06XZL2PQD/ref=sr_1_2_sspa?s=electronics&ie=UTF8&qid=1516627992&sr=1-2-spons&keywords=50W+amplifier+8+ohms&psc=1

Watt for dollar they are very cheap. You could always upgrade the avr instead. Installing the amp you linked will almost be certain to give you issues. You need a robust amp for long speaker runs and you should always get a 4ohm stable amp for distributed audio. It's not necessarily the power but the quality of the amp section and power supply. The amp you linked would probably work well in a small room with efficient speakers like Klipsch

 

[highfigh]

Ok thanks but Crown amps are $$$$$ it's $230 for a 300W amp. Is there another recommendation? I was looking at this https://www.amazon.com/Channel-Audio-Amplifier-Speakers-TPA3116/dp/B06XZL2PQD/ref=sr_1_2_sspa?s=electronics&ie=UTF8&qid=1516627992&sr=1-2-spons&keywords=50W+amplifier+8+ohms&psc=1

$230 for 300W is cheap, but it still doesn't address the problem.

You know the speaker wires go into the attic, but not if they have any splices or if someone put a remotely located volume control. Both could be where the problem lies. If they spliced and didn't protect the wires, moisture and/or insects could have gotten into the connection, causing this. It could be some kind of animal that chewed the wires, too. If there is a volume control, you'll need to remove it from where it's mounted and see if it has moist spider webs/nest contacting the wires and solder joints on the control. If it's not in a junction box and it was mounted in an outside wall or in a garage/shed, it should be sealed. You'll need to inspect the speaker wire between the speakers and wherever it comes out of a wall- if it's buried in the ground, you need to disconnect the wires at both ends and check for continuity between each wire and the electrical ground AND the ground itself. A ground rod or cold water supply pipe is a good place to use as a reference. If the speaker wires are buried close to the electrical ground, make sure you can't measure voltage on the speaker wires.

 

[delaneybob]

I went to attic and there was a splice on one speaker cable (4 wire)- all 4 are sliced only 2 are used. It ware done without connectors and duck tape- I plan to put lugs on them and retape with electrical tape. The ohm was 7 ohms on the splice and 2 on the non spliced cable.

Good plan? trying to avoid rerunning the cable

 

[delaneybob]

Also I recalibrated the fluke- the resistance now is 0 ohms with both wires shorted and infinite with them open

 

[TLS Guy]

Ok thanks but Crown amps are $$$$$ it's $230 for a 300W amp. Is there another recommendation? I was looking at this https://www.amazon.com/Channel-Audio-Amplifier-Speakers-TPA3116/dp/B06XZL2PQD/ref=sr_1_2_sspa?s=electronics&ie=UTF8&qid=1516627992&sr=1-2-spons&keywords=50W+amplifier+8+ohms&psc=1

You will blow that amp up fast. The Crown amp is a very competitively and reasonable priced amp.
You can't do this sort of thing on the cheap, and if you do you will pay more in the long run.

 

[delaneybob]

You will blow that amp up fast. The Crown amp is a very competitively and reasonable priced amp.
You can't do this sort of thing on the cheap, and if you do you will pay more in the long run.

Thanks- I think l found the issue in the attic- thanks Highfigh!. I am going with that being the cause. Hopefully it's fixed- if not will post back

Thanks for all the responses!!!