Denon 3805 and 4 ohm speakers

[Buckeyefan 1]

This is the third time Denon techs have told consumers not to pair their receivers with 4 ohm speakers. See post #5. They told me the exact same thing.

http://www.avsforum.com/avs-vb/showthread.php?t=595647

 

[gene]

Hmm I don't see a post from a Denon tech anywhere in that thread. Oddly enough, Denon was using 4 ohm speakers in a demo they did on the 3805 when it first came out. Clint used 4 ohm speakers for nearly a year on the 3805 without any issues. You may wish to recheck your sources.

 

[Buckeyefan 1]

Hmm I don't see a post from a Denon tech anywhere in that thread. Oddly enough, Denon was using 4 ohm speakers in a demo they did on the 3805 when it first came out. Clint used 4 ohm speakers for nearly a year on the 3805 without any issues. You may wish to recheck your sources.

My source was the Denon customer service dept. who transferred me to the tech department. I know it's hard to believe, but call them tomorrow and ask them directly. If they're giving bad info, we should probably correct them.

973-396-0810

 

[Audioholics]

There's that "we" again...

 

[PENG]

Buck, on page 16 of the 3805's manual it says:

"Note on speaker impedance

The protector circuit may be activated if the set is played for long periods of time at high volumes when speakers with an impedance lower than the specified impedance (for example speakers with an impedance of lower than 4 Ω/ohms) are connected. If the protector circuit is activated, the speaker output is cut off. Turn off the set’s power, wait for the set to cool down, improve the ventilation around the set, then turn the power back on".

This implies that it can drive 4 ohms speakers. Denon's FAQ section also says they can do it. When people say they talked to Denon, did they end up talking to some sales people who simply refer to the specifications, that for sure refer to 8 ohms load only.

 

[gene]

Their tech person is likely saying this for liability purposes since the receiver doesn't have UL certification for 4 ohms or that dreaded impedance switch.

Most reasonably efficient 4 ohm loads wont be a problem for this receiver. In this receiver's price class it has one of the most robust amp sections and Clint drove M80s on this receiver for nearly a year (sometimes blasting it at ear bleeding levels in a 3000+ cubic foot room.)

I don't really need to speak with their tech support since we usually deal directly with their engineers

 

[PENG]

My source was the Denon customer service dept. who transferred me to the tech department. I know it's hard to believe, but call them tomorrow and ask them directly. If they're giving bad info, we should probably correct them.

973-396-0810

Sorry, I guess we were all posting at around the same time.

 

[j_garcia]

If you are running only two or three 4 Ohm speakers it probably won't be an issue. Running all 4 Ohm speakers would probably not be a good idea over a long period of time, especially if you have a large room or listen at relatively elevated levels. My speakers are all 4 Ohm and my Marantz is rated for 6 Ohms minimum and I also have a pretty large room at about 4500 cf. I was told it would be OK when I mentioned to the shop I bought it from that I was buying 4 Ohm speakers. It worked fine running two 8 Ohm rears with three 4 Ohm mains, but it was also clear that when I really cranked it that it was running out of steam so I added the monoblocks. When cranked up, there was a definite improvement, which tells me the receiver didn't have enough juice.

What I'm getting at is, the 3805 will probably be capable of driving a full compliment of 4 Ohm speakers, however, that does not mean it will do it well.

 

[gene]

What I'm getting at is, the 3805 will probably be capable of driving a full compliment of 4 Ohm speakers, however, that does not mean it will do it well.

Very True!

 

[MDS]

Is it not also true that alot depends on the actual impedance curve of the speakers?

The nominal impedance of a speaker is essentially an average. A speaker with a 4 ohm nominal impedance may dip well below 4 ohms. I've seen graphs for some speakers (Dali, didn't buy them anyway) where the speaker is rated at 4 ohms but maintains a relatively constant 4 ohms across the spectrum. Assuming those measurements were actually accurate, wouldn't such a speaker be easier to drive than a 'typical' 4 Ohm speaker that dips well below that nominal rating?

If I recall correctly, the demo room where I listened to the Dali speakers was using a Denon 3802 and it didn't seem to be straining at high volumes.

 

[PENG]

I also think the 3805 can handle 4 ohm speakers under some conditions, but I would definitely add at least a 2 or 3 channel amp.

 

[mtrycrafts]

Buck, on page 16 of the 3805's manual it says:

"Note on speaker impedance

The protector circuit may be activated if the set is played for long periods of time at high volumes when speakers with an impedance lower than the specified impedance (for example speakers with an impedance of lower than 4 Ω/ohms) are connected. If the protector circuit is activated, the speaker output is cut off. Turn off the set’s power, wait for the set to cool down, improve the ventilation around the set, then turn the power back on".

This implies that it can drive 4 ohms speakers. Denon's FAQ section also says they can do it. When people say they talked to Denon, did they end up talking to some sales people who simply refer to the specifications, that for sure refer to 8 ohms load only.

Thanks for digging deeper
How true. Since it isn't rated RMS at 4 Ohms, driving such loads and lower impedance at high levels will be an issue. Otherwise, why would it be a problem since not all the speakers are active with high level signals at the same instant, hence there is no real demand beyond one or two channels. Now we are back to the all channel driven issue that will not happen either, realistically.

 

[rikmeister]

ok here is my questions . since i just bought a denon 3805 and now i have a super

deal on the dali euphonia ms5 . i will only be buying the front two. will my receiver drive them. the deal is too good to be true. but the speakers are close to me so i can go and look at them without sending money and waiting for them. i will buy the center channel later when i pay of the two fronts.

 

[Jack Hammer]

I've got a Denon 2805 and have been driving 4 ohm speakers in the front, center, and surrounds, plus two 8ohm surround back speakers without any problems. I don't listen at reference levels and am in a small to medium size room. I've checked my reciever several times and it does not get hot. So, I'm not really worried about it.

Jeff

 

[mulester7]

There's that "we" again...

....how did I miss this one?....I offer the Old Chinese statement of, "mouse aboard, in honorable pocket".....

 

[Krisso]

I've just purchased the 5.1 signature series from RBH (4ohm all round). I havent purchased the reciever yet, however I have my eye on the Denon 3806.
After spending hard earned money on speakers, matching it with the correct AV reciever is obviously important.

I hope the 3806 is the right choice. Im a little concerned now

2 x 1266SE
1 x 661SE/R
2 x 66SE
1 x 12SE

 

[mulester7]

I've just purchased the 5.1 signature series from RBH (4ohm all round). I havent purchased the reciever yet, however I have my eye on the Denon 3806.
After spending hard earned money on speakers, matching it with the correct AV reciever is obviously important.

I hope the 3806 is the right choice. Im a little concerned now

2 x 1266SE
1 x 661SE/R
2 x 66SE
1 x 12SE

.....Krisso, choose whatever receiver you wish, and help it feed less 4 ohm mouths asap....mercy, that Earthquake 3-channel amp for $1399 sure did look good.....

http://www.federalstereo.com/federalstereo/earsouncin3.html

 

[tdeluce]

.....Krisso, choose whatever receiver you wish, and help it feed less 4 ohm mouths asap....mercy, that Earthquake 3-channel amp for $1399 sure did look good.....

http://www.federalstereo.com/federalstereo/earsouncin3.html

Yes it does. Can't wait to hook it up tonight

 

[mulester7]

Yes it does. Can't wait to hook it up tonight

.....TDeluce, I suspect there are persons at this site who would love to hear a report....one item, check your specs in the manual accompanying the amp....what is the damping factor rating?......

 

[tdeluce]

.....TDeluce, I suspect there are persons at this site who would love to hear a report....one item, check your specs in the manual accompanying the amp....what is the damping factor rating?......

May not get to hooking it up tonight - might have to wait until tomorrow -
orderd some new Blue Jean cables that didn't come in today and don't
want to mess with the wiring twice...

But the only specs in the manual I have other than those below is that
the amps are hand assembled hand tested before shipping ( mine
was tested on 11-07-05 ) and found to have a THD+N of 0.005 ( yes!
three decimal places ) in each channel with a 4 ohm load and a
SNR of 117.0 ; 116.9; 117.1 in the LCR amps respectively - pretty frig'in amazing if true...

You can remove each amplifier for service by simply pulling it out and
the other two will continue to work just fine...

It has a 20 AMP circuit breaker on the back panel a 20 amp rated
cord is also supplied.

They claim to have developed a 15GHz! switcher that allowed their
engineers to use a lesser number of components in the audio path.
"Users are able to enjoy pure music, untainted by component distortion."

I have two 20 Amp isolated circuits and I am going to place this bad
boy on one of them all alone



---- specs --------------

Number of channels: Three discrete monaural blocks.
Power rating per channel:
(8-ohm load), all channels driven: 300 watts.
(4-ohm load), all channels driven: 600 watts.
(2-ohm load), all channels driven: 1000 watts.
Freq. Response (@1 W w/ ±0.1dB: 20 Hz to 20 kHz.
Channel separation: greater than 95 dB.
Max. input voltage: 1.9 volts.
Input impedance: 27,000 ohms.
Total harmonic distortion -THD:
1 kHz, 8-ohm load: 0.001%.
20 kHz, 8-ohm load: 0.003%.
1 kHz, 4-ohm load: 0.003%.
20 kHz, 4-ohm load: 0.006%.
1 kHz, 2-ohm load: 0.005%.
20 kHz, 2-ohm load: 0.006%.
Signal to noise ratio:
@ 1 kHz, 112 dB.
@ 5 kHz, 111 dB.
@ 10 kHz, 110 dB.
High-pass / low pass variable filter, range 20 Hz to 5 kHz (one/ channel).
High-pass/Full range/Low pass operation via 3-way switches (one switch per channel).
Dimensions: 9.25" x 18" x 21" (H x W x D).
Gross Weight : 119 lbs .