True, that's why if in doubt, take 3 dB off the specified sensitivity if it is stated X dB/2.83V/1m, then it should be enough to allow for those 3 to 4 Ohm dips. Of course some speakers have worse phase angles than others, but phase angles usually are not much of an issue for electromagnetic/moving coil loudspeakers. In the Stereophile review, the phase angle wasn't too bad except in the 650 to 2 K range where the impedance was about 4 Ohms or higher. The MM7025 should have no trouble with that but it still depends on the spl and distance, that's why the OP should use the calculator to figure out his power need first. To avoid overheating due to large phase angles (especially if coincide with low impedance), I would put a fan on top, in fact I do that regardless.
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Denon AVR-X3700H AVR Review
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True, that's why if in doubt, take 3 dB off the specified sensitivity if it is stated X dB/2.83V/1m, then it should be enough to allow for those 3 to 4 Ohm dips. Of course some speakers have worse phase angles than others, but phase angles usually are not much of an issue for electromagnetic/moving coil loudspeakers. In the Stereophile review, the phase angle wasn't too bad except in the 650 to 2 K range where the impedance was about 4 Ohms or higher. The MM7025 should have no trouble with that but it still depends on the spl and distance, that's why the OP should use the calculator to figure out his power need first. To avoid overheating due to large phase angles (especially if coincide with low impedance), I would put a fan on top, in fact I do that regardless.
Bear123
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2 speakers should not be used in the calculator, and room gain/boundary reinforcement should not be added in either IMO. SPL requirements are per speaker, and room/boundary gain only affects lower frequencies. Sensitivity is usually rated up into the region where room gain does not help. I don't think an 89 dB speaker from 1KHz-10KHz, for example, gains higher sensitivity in that range from being placed in a room or near boundaries. Open to correction if I'm mistaken.
As for the external amp, yes it may help during very loud playback which I did include in my post. It's uncommon IME for people to listen much louder then -15 or -10MV. Listening levels, speaker sensitivity, impedance, and listening distance of course all play a role into wether more power would be of benefit.
I am in the fortunate position that my even older Denon X3300 provides what I need for my situation. Given my playback levels, listening distance, and speaker sensitivity, upgrading AVR's and/or external amps/DAC's would make zero audible difference. I'm confident the .007% SINAD I get from the 3300 would sound exactly the same as the .0017% I would get using an external amp.
As for the external amp, yes it may help during very loud playback which I did include in my post. It's uncommon IME for people to listen much louder then -15 or -10MV. Listening levels, speaker sensitivity, impedance, and listening distance of course all play a role into wether more power would be of benefit.
I am in the fortunate position that my even older Denon X3300 provides what I need for my situation. Given my playback levels, listening distance, and speaker sensitivity, upgrading AVR's and/or external amps/DAC's would make zero audible difference. I'm confident the .007% SINAD I get from the 3300 would sound exactly the same as the .0017% I would get using an external amp.
I think it depends on how you like to listen to your music? If you're locked into two channel stereo only then I agree. But, if you like to explore using Multi-channel Stereo, then preamp mode on the 3700 is an awesome tool for off-loading to more powerful external amps.
Bear123
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The overly obsessive pursuit of SINAD here can be misleading at times. If you indeed need more power, the absolute worst case scenario for your AVR using an external amp would be a signal with .02% SINAD. That "abysmal" performance is probably as good or better than 95% of all external amps made, regardless of audiophile pedigree or cost. Paired with the correct amp, SINAD is .0017% or -95 dB from the pre-outs. Better than all but a very small handful of external amps. But you have to make sure the amp you are driving doesn't need more than 1.5 volts. At 2 volts, SINAD is .02%. This is the number that has labeled the X3500 as "not good" or "poor" or "abysmal". In real life, it is probably audibly transparent.
The X3500's internal amps and DAC produce a SINAD of .008%. If you need more power, the pre-outs range between .0017% and .02% depending on voltage. So if you listen at reference level using an amp that requires a lot of voltage, you will send a signal with .02% distortion to speakers producing 1% or higher distortoin. This is why I'm saying the SINAD judgements need to be taken with a huge grain of salt.
If starting from scratch, sure, it makes sense to take a well engineered product into consideration. But to go from audible transparency with a Denon 3500, to even more audible transparency with an X3700, may not make sense, unless you need more channels or features.
As an example, the Parasound Halo A21 amplifier, a very highly regarded audiophile 2 channel external amp, has distortion performance rather similar to the X3500. The X3500 is better in some areas.
From John Atkinson's Stereophile review of the A21:
"The Parasound A 21+ offers a lot of low-distortion power....."
Parasound Halo A21 Stereophile review
So a multi thousand dollar audiophile 2 channel amp is praised for its low distortion. But the Denon 3500, with as good or better SINAD is "bad".......
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Very much agree. I own a Denon x3400 and run a 5.1.2 which only allows for 7 speakers. Adding an amplifier doubled my available wattage compared to just the x3400 which made an improvement at high listening levels -17db or higher below that indistinguishable
Call it what you will, imho more power matters and 105 watts is not that much. But if you have convensed yourself otherwise and you are happy with what yo I have, you are better off than 99% of the people here
Bear123
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I'm not saying more power never matters. Sometimes it matters, sometimes it doesn't. In my case, my Denon provides more power than I need. For folks that listen louder, or sit further, or have less sensitive speakers, or some combination, more power may matter.Call it what you will, imho more power matters and 105 watts is not that much. But if you have convensed yourself otherwise and you are happy with what yo I have, you are better off than 99% of the people here
CoolHandDuke
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How are you powering the fan? Mine arrived today on your recommendation.
I'm using the Monoprice surge protector (Product # 9203) with USB charger ports. This lets me turn on the fans and the receiver/ext amp at the same time: https://www.monoprice.com/product?c_id=312&cp_id=31207&cs_id=3120701&p_id=9203&seq=1&format=2
I have also used an iPad or iPhone charger: https://www.amazon.com/Panmy-Foldable-Portable-Charging-Compatible/dp/B07DC4J387/
Or the Joto 2 outlet.
https://www.amazon.com/gp/product/B01AT23UGE/
Many here will recommend a hypex amp instead
Does the av receiver not have a usb output? Maybe that would make it more automatic.
You could use the USB port on the front of the Denon 3700, but I prefer to leave that for USB drives.
CoolHandDuke
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I initially plugged into 3700, but thought it looked less than "clean" so used an older apple charging adapter. Only downside is it will be running all the time unless I physically turn it off. Fans are nice, very quiet, and can't be seen in my component rack.
The AC Infinity MULTIFAN S7 is nice and quiet on the low setting and does a great job cooling the Denon 3700. I would not leave it running when not using the receiver. That's why I prefer to plug it into the same surge protector as the Denon 3700 and turn that strip off when my receiver is not working.
I use this same method to reduce phantom power draw of electronics through my home.
Hi all,
I've got an AVR-X3700H, which I use for mixed music/movie listening, running in a 5.1 layout. I am planning to add an external power amp mostly to drive new L/R speakers that I believe from some additional power. Although this is mixed use between music and home theater, I'm perfectly happy with the performance of the AVR when it comes to driving the center and surround speakers, but would like to put more power behind the L/R especially for music, for which sound quality is much more important to me.
With that in mind, I'm trying to decide between adding a 2- versus a 5-channel amplifier. Based on Amir's review, there appears to be some sonic benefit (in theory, at least) to using a 5-channel external amp so that the unit can be placed in pre-amp mode, disabling ALL its internal amplifiers. However, this AVR can also power down JUST the front L/R channels by using the 11.1 Amp Assign mode.
My question: considering JUST 2-channel music listening, is putting the AVR in full pre-amp mode preferable to disabling just the front L/R internal amps? (I know that for 5-channel movie content, pre-amp mode, with all amplification happening externally, is theoretically preferable, but this question is specifically about the performance of the AVR as a pre-processor for 2-channel listening.) In other words, is there benefit to a 5-channel external amp just for 2-channel listening, by virtue of being able to power down all the internal amplifiers? Or would the AVR behave equivalently for 2-channel listening when using Amp Assign to power down just the front L/R amps using a 2-channel external amplifier?
Thanks for your help!
I've got an AVR-X3700H, which I use for mixed music/movie listening, running in a 5.1 layout. I am planning to add an external power amp mostly to drive new L/R speakers that I believe from some additional power. Although this is mixed use between music and home theater, I'm perfectly happy with the performance of the AVR when it comes to driving the center and surround speakers, but would like to put more power behind the L/R especially for music, for which sound quality is much more important to me.
With that in mind, I'm trying to decide between adding a 2- versus a 5-channel amplifier. Based on Amir's review, there appears to be some sonic benefit (in theory, at least) to using a 5-channel external amp so that the unit can be placed in pre-amp mode, disabling ALL its internal amplifiers. However, this AVR can also power down JUST the front L/R channels by using the 11.1 Amp Assign mode.
My question: considering JUST 2-channel music listening, is putting the AVR in full pre-amp mode preferable to disabling just the front L/R internal amps? (I know that for 5-channel movie content, pre-amp mode, with all amplification happening externally, is theoretically preferable, but this question is specifically about the performance of the AVR as a pre-processor for 2-channel listening.) In other words, is there benefit to a 5-channel external amp just for 2-channel listening, by virtue of being able to power down all the internal amplifiers? Or would the AVR behave equivalently for 2-channel listening when using Amp Assign to power down just the front L/R amps using a 2-channel external amplifier?
Thanks for your help!
With the Denon 3700 you have two Presets on the receiver. This would allow you to setup the receiver in Preamp mode and use it in stereo with an external amp. Then, you could setup the other preset to use the internal Denon amps for 5.1 with or without the external amp. When you switch between presets these two settings switch automatically.
If you have a high quality amp like the Monolith 2x200 or 5x200 it makes sense to use preamp mode as it reduces the load on the receiver and allows it to run cooler. However, you can easily use the 3700 without an external amp as well. The reason I would go with an external amp is if the speakers dip below 4ohms or if reference volume levels are desired.
As far as sound differences with or without external amps? My experience is the Speakers sound a little crisper with the Monolith external amp and I'm able to operate in Multi-channel Stereo mode without stressing the receiver. Other than that, there is little difference between using the internal amps and an external Monolith.
If you have a high quality amp like the Monolith 2x200 or 5x200 it makes sense to use preamp mode as it reduces the load on the receiver and allows it to run cooler. However, you can easily use the 3700 without an external amp as well. The reason I would go with an external amp is if the speakers dip below 4ohms or if reference volume levels are desired.
As far as sound differences with or without external amps? My experience is the Speakers sound a little crisper with the Monolith external amp and I'm able to operate in Multi-channel Stereo mode without stressing the receiver. Other than that, there is little difference between using the internal amps and an external Monolith.
In my experience there is no audible difference between using the internal amps and the external amps (Anthem MCA, Parasound A21 etc..) whether the internal amps are disconnected or not. The theoretical difference doesn't kick in until the pre out voltage >1.4 to 1.5 V, for most home use sitting 10-13 ft, using 4 to 8 Ohm speakers with sensitivity 90 dB/2.83V/1m, you can hit reference level, that I bet most people can't stand anyway.
So to me, and I think a lot of people (those who have speaker sensitivity in the high 80's and don't sit too far) too, preamp modes is nice and it helps the AVR to run cooler but to hear the theoretical sonic benefits one would have to have good imagination and listen to near reference level. Even then, it will only be during the peaks of 15 dB or higher. Still, it is good to have external amps for other reasons, and that's why I have them.
So to me, and I think a lot of people (those who have speaker sensitivity in the high 80's and don't sit too far) too, preamp modes is nice and it helps the AVR to run cooler but to hear the theoretical sonic benefits one would have to have good imagination and listen to near reference level. Even then, it will only be during the peaks of 15 dB or higher. Still, it is good to have external amps for other reasons, and that's why I have them.
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That's a good point about switching between the two presets. But, since that's one more setting to be mindful of, I'm still interested in whether there would be some sonic benefit (in theory at least) to powering down all all amps with pre-amp mode vs just powering down the front L/R using the 11.1 layout?
Thanks Peng, that helps! It sounds like perhaps the main benefit of getting a 5- vs 2-channel external amp might just be to reduce the running temperature (and hence increase the lifetime) of the AVR.
That, and also as amper42 said, "if the speakers dip below 4ohms or if reference volume levels are desired.", though that only applies if you are actually pushing the internal amps close to the limit.
This calculator should help you find out how close it is to the limit without the help of a high power external amp:
Peak SPL Calculator (homestead.com)
The example below shows that for near reference level the AVR-X3700H (rated about 100 W average/200W peak) should be do it if you sit from 12 feet and your speaker's sensitivity is 90 dB/2.83V/1m, with 8 ohm nominal impedance. The pre out voltage in this example would be about 1V, and SINAD at that point should be higher than 100 dB. It should theoretical "sound" as good as just about any "external" power amp Amir has measured on ASR. Try find one, other than the AHB2 and those Purifi/Hypex based amps that could match the SINAD/THD+N or the AVR-X3700H and I would like to know.
We can argue that THD+N is not the only determining factor, so feel free to compare IMD, FR as well..Again, if affordability is not the issue, please do get an external amp, but get one that measures better than the Denon and with rated output >200 W into 8 ohms for a 3 dB gain, just to feel good if nothing else.
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Thank you Peng, that's why i go for just the avr without external amplification.
