CHT400 Overheating and AVR1912
jpclick
Posts: 2
I have just recently moved houses and have just purchased a new Home Theaters System for the Family Room. The room is situated in such a way that a sound bar was the best option for me.
I have been a long time Polk Audio Customer, so I decided to go with the CHT400. I have a 47 inch TV and the CHT400 fit perfectly; I have it mounted under the TV. The TV is on a arm. For the receiver, I read the reviews and the Denon AVR1912 seemed to be the right fit plus I am a big Itunes user, so I liked the Airplay option on the Denon.
The issue I have is that at high volume, the AVR-1912 overheats. I have the AVR1912 set to Absolute Volume, not relative. I have been testing at 85 out of 100. Unfortunately, I don't know what the DB levels are at 85. Nonetheless, the AVR1912 will overheat in 3 to 5 minutes like clockwork. It will go into protect mode.
75 is probably where I would listend to music and movies normally, 85 is when I want it a bit louder. This is not super loud, but it is enjoyable.
AVR1912 has 3 inches of clearance on all sides and there is no back on my cabinet.
This is what I have done so far:
Reduced the CHT400 from 7.1 to 5.1, no change
Placed a fan at highspeed next AVR1912, no change (maybe lasted a minute longer)
Removed AVR1912 from cabinet place on top, no change
RMA'd the CHT400, no change
RMA'd AVR 1912 and used new AVR1912 place on top of cabinet, no change
Reduced CHT400 from 5.1 to 3.1, no change (maybe lasted a bit longer)
Took the spare AVR1912 (I have one RMA'd) to the Basement and plugged in my Bose Acoustimass 15 (powered subwoofer and 5.1 systems with dual cubes), The AVR did not overheat. I could play at 85 level for 1.5 hours, the AVR got warm but never overheated.
My conclusion was the CHT400 was somehow causing the AVR1912 to overheat. I purchased the CHT400 and AVR1912 from Crutchfield.
So I called Crutchfield Tech Support to discuss my findings and he said that the Soundbars (not just Polk Audio, but any) at high volume have the tendancy to lose the Ohm level, thus causing the receiver to overheat. They also said that that had seen this problem before with Soundbars. They suggested that I get indiviual speakers and keep the reciever. The way my family room is configured, the Soundbar is the best way for me to go.
So, I am wondering if this is true. If so, how do I fix this?
Can I get a better reciever?
Can I enhance the wire with some sort of filter that keeps the reciever from seeing the lower Ohm level?
I have been a long time Polk Audio Customer, so I decided to go with the CHT400. I have a 47 inch TV and the CHT400 fit perfectly; I have it mounted under the TV. The TV is on a arm. For the receiver, I read the reviews and the Denon AVR1912 seemed to be the right fit plus I am a big Itunes user, so I liked the Airplay option on the Denon.
The issue I have is that at high volume, the AVR-1912 overheats. I have the AVR1912 set to Absolute Volume, not relative. I have been testing at 85 out of 100. Unfortunately, I don't know what the DB levels are at 85. Nonetheless, the AVR1912 will overheat in 3 to 5 minutes like clockwork. It will go into protect mode.
75 is probably where I would listend to music and movies normally, 85 is when I want it a bit louder. This is not super loud, but it is enjoyable.
AVR1912 has 3 inches of clearance on all sides and there is no back on my cabinet.
This is what I have done so far:
Reduced the CHT400 from 7.1 to 5.1, no change
Placed a fan at highspeed next AVR1912, no change (maybe lasted a minute longer)
Removed AVR1912 from cabinet place on top, no change
RMA'd the CHT400, no change
RMA'd AVR 1912 and used new AVR1912 place on top of cabinet, no change
Reduced CHT400 from 5.1 to 3.1, no change (maybe lasted a bit longer)
Took the spare AVR1912 (I have one RMA'd) to the Basement and plugged in my Bose Acoustimass 15 (powered subwoofer and 5.1 systems with dual cubes), The AVR did not overheat. I could play at 85 level for 1.5 hours, the AVR got warm but never overheated.
My conclusion was the CHT400 was somehow causing the AVR1912 to overheat. I purchased the CHT400 and AVR1912 from Crutchfield.
So I called Crutchfield Tech Support to discuss my findings and he said that the Soundbars (not just Polk Audio, but any) at high volume have the tendancy to lose the Ohm level, thus causing the receiver to overheat. They also said that that had seen this problem before with Soundbars. They suggested that I get indiviual speakers and keep the reciever. The way my family room is configured, the Soundbar is the best way for me to go.
So, I am wondering if this is true. If so, how do I fix this?
Can I get a better reciever?
Can I enhance the wire with some sort of filter that keeps the reciever from seeing the lower Ohm level?
Post edited by jpclick on
Comments
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It might be possible that the Crutchfield technician mispoke or you might have possibly misheard his response, but no speaker/soundbar (from any company) should be "Losing ohm levels at high volume levels".
At lower frequencies, a coil's "resistance" will decrease; at 0 hz, the coil's "resistance" will be 0 ohms (rounding off).
At 0 hz, your coil presents 0 resistance to the AVR output and the AVR thinks it's now a toaster.
Of course, music may have low freqencies, but certainly not 0 hz. If you're getting close to apparent 0 hz, that's because your output is clipping like a mad man, and you should certainly hear it.
How could you get clipping ? By trying to get as much lower bass out of ANY soundbar as you do out of a box speaker.
With your 1912 running your Bose system, you were running a system that had a separate powered subwoofer.
If you try to get ANY soundbar to deliver the same amount of bass, you will probably experience problems.
In your Denon system setup, try setting your soundbar to "small" and cheat the 1912 and tell it that you have a subwoofer; set that crossover to something high like 120 hz.
This will sound like ****, to be sure, but see if that clears up the Denon overheating problem.
The Horde Downstairs run a Soundbar off an Insignia AVR (re-branded Onkyo, a cheapo) at rather insane levels with no problem; that system does have a subwoofer, though.Sal Palooza -
I should have been more specific, my speakers are setup as you describe above. Small, 120hz, and I do have a PSW111 that was part of a package deal with the CHT400. Actually, my first CHT 400 had a bad speaker in it, so I had increased to 150Hz, which helped with the distortion but did nothing for the overheating. That unit was rpelaced, so I am back to 120hz.
I pulled my old Harmon Kardon out of the garage. It is rated at 50w per channel and it is a 7.1 receiver. I rewired the CHT400 to connect to the HK AVR235 and put the volume to 5db and it ran fine for quite a while, well over 20 minutes (the AVR1912 only would last 5 miuntes or so). I use Itunes for 95% of my music, I have a server and many AppleTV devices. This is why I liked AirPlay on the Denon. THe Harmon Kardon doesn't have HDMI ports, let alone AirPlay. In order to perform this test, I plugged an AppleTV into the Optical Port of the HK AVR 235.
This gave me an idea. Instead of using Airplay on the Denon, I will test with AppleTV. With this test, the unit did not overheat. I played for a full 30 minutes. So, I think there is a problem with HighVolume and Airplay on this Denon AVR1912. I do find it interesting that Full Volume on the Apple Remote/Itunes only allows the Denon to 75, maybe they know something. I usually have to go to the unit and force it up to 85.
