Anyone running 4ohm loads on a Denon AVR-4806 CI ?

[DIY Junky]

Hi its me again. I am looking to build a speaker kit Denovo Audio helix ribbon MTM with 7" drivers and 3.5" Fountek ribbon tweeters. The kit is rated at 4 Ohms and my Denon AVR-4806 CI ..States 6-8 ohm loads. Am I being overprotective or should I stick to 6-8 ohm kits ? Thanks for any advice on this matter.

 

[lovinthehd]

Couldn't find a bench test but seems it worked for this guy's use https://hometheaterhifi.com/volume_12_4/denon-avr-4806-receiver-12-2005-part-4.html

 

[shadyJ]

Do you have an impedance/phase response of those speakers you can share? Even if they are 4 ohms nominal load, that still might not be bad depending on the shape of the response. If that speaker is not terribly engineered, it should play fine with the Denon.

 

[bikdav]

Hi its me again. I am looking to build a speaker kit Denovo Audio helix ribbon MTM with 7" drivers and 3.5" Fountek ribbon tweeters. The kit is rated at 4 Ohms and my Denon AVR-4806 CI ..States 6-8 ohm loads. Am I being overprotective or should I stick to 6-8 ohm kits ? Thanks for any advice on this matter.

I have no idea what this impedance thing is all about. My guess is that it is a UL listing political move [being over protective]. It got going big time when home theater came out. I have run many 4 Ohm speakers on receivers that claim to be good for 6-8 Ohms only and have had no problems whatsoever.

 

[shadyJ]

I have no idea what this impedance thing is all about. My guess is that it is a UL listing political move [being over protective]. It got going big time when home theater came out. I have run many 4 Ohm speakers on receivers that claim to be good for 6-8 Ohms only and have had no problems whatsoever.

It has nothing to do with UL. AVR manufacturers don't like returns so they would rather the consumer just use speakers that are easy electrical loads. It also allows them to deny warranty repairs for people who were using speakers with tougher electrical loads. And the amplifiers in AVRs aren't getting better with successive models anymore, so an easy electrical load probably is a good idea with lower end AVRs. Yes, you can use 4 ohm speakers with amps only spec'd for 8, and it can work for awhile, but you may be dramatically shortening the AVR's lifespan. I used a 4 ohm speaker with an Onkyo TX-SR707 and that Onkyo only lasted 4 years. I also used another 4 ohm speaker with an H/K 3490, and that also died after 4 years, and that thing was spec'd to handle 4 ohm speakers.

 

[DIY Junky]

Do you have an impedance/phase response of those speakers you can share? Even if they are 4 ohms nominal load, that still might not be bad depending on the shape of the response. If that speaker is not terribly engineered, it should play fine with the Denon.

No just basic spec chart. No graphs. I take it you mean the load at volume levels graph ? Min load and peak load kinda thing.

 

[DIY Junky]

Couldn't find a bench test but seems it worked for this guy's use https://hometheaterhifi.com/volume_12_4/denon-avr-4806-receiver-12-2005-part-4.html

Its a good receiver. Back when Denon was a good name. Wouldn't the Amp shut down if over heated ? I have an old Carver that would shut down if I pushed it too hard ?

 

[lovinthehd]

One with impedance vs frequency, phase angles would be nice, too. Like here https://www.audioholics.com/loudspeaker-design/understanding-impedance-electrical-phase/page-2

 

[lovinthehd]

Its a good receiver. Back when Denon was a good name. Wouldn't the Amp shut down if over heated ? I have an old Carver that would shut down if I pushed it too hard ?

I have a Denon 3808 and a 4520, I'd run 4ohm speakers but.... What's the sensitivity spec? How loud do you want them to play at what distance?

 

[PENG]

There aren't much point worrying about the 4 ohm thing in isolation because whether a certain amplifier is suitable for the so called 4 ohm speakers depend a lot on the final sound pressure level you need at your listening position, and as mentioned, the actual impedance versus frequency characteristics. For example, if the "nominal" 4 ohm value is a result of the impedance in frequency ranges mostly outside of the bass and mid bass, and if the impedance in the bass/mid bass bands are actually closer to 8 ohms, then the speaker maybe relatively easier to drive than a 8 ohm nominal rated speaker that could have dips in the lower frequencies.

SPL depends much on the distance and sensitivity. Take a look of the examples of speakers with different sensitivity, impedance, and maximum spl specifications below:

Speaker A - 90 dB/2.83V/1m , 4 ohms, 110 dB, distance 4m

Speaker B - 87 dB/2.83V/1m, 8 ohms, 115 dB, distance 4m

Speaker C - 88 dB/1W/1m, 4 ohms, 108 dB, distance 2m

All else being equal, which one is easiest to drive for an amp that is rated for 4 ohm?

Based on data given above:

- One possible correct answer would be speaker B if one wants to achieve the highest possible sound pressure level at a given distance, otherwise A and B would be equal, again, only if all else being equal.

- If the spl needed is 105 dB, then speaker C, still the worst load among the 3, but because of the shorter distance, would be easier on the amplifier.

Sorry about my friendly ranting, but it really is difficult to answer questions about concerns of using an AVR to drive 4 ohm speakers, when only the nominal impedance information is given.

All else being equal again, I am confident to say all Denon AVR-3800 and 4800 series AVR can handle 4 ohm nominal rated speakers as well as, or better than most separate pre-amp/power amps rated 100 to 120 W per channel, two channel being driven simultaneously.

I would suggest, in general, use the online calculator linked below to find out the power you need and double it to allow for a safety margin, or use the Crownaudio calculator, without doubling the result.

http://myhometheater.homestead.com/splcalculator.html

Note: the above linked calculator is based on sensitivity specified for 1 watt/1 meter so for 4 ohm speakers specified x dB/2.83V/1m, deduct 3 dB before entering the number.

 

[PENG]

I have a Denon 3808 and a 4520, I'd run 4ohm speakers but.... What's the sensitivity spec? How loud do you want them to play at what distance?

Those two are more powerful in the real world than a lot of the integrated and separate preamp/power amp with the same advertised rated power. I don't mean to compare them to Krell, Passlab, Boulder amps, but to Emotiva, NAD (the lower models) and D&M's own etc.

 

[Swerd]

Hi its me again. I am looking to build a speaker kit Denovo Audio helix ribbon MTM with 7" drivers and 3.5" Fountek ribbon tweeters. The kit is rated at 4 Ohms and my Denon AVR-4806 CI ..States 6-8 ohm loads. Am I being overprotective or should I stick to 6-8 ohm kits ? Thanks for any advice on this matter.

This MTM speaker is very sensitive, rated at 91 dB at 2.83 volts. It should be easy to drive, and that Denon AVR is no slouch. You're probably being overprotective, as was Denon. But your question would be easy to answer by looking at an impedance vs. frequency curve for the speaker. Ask DIY Sound Group if they can provide one. I can't imagine that Jeff Bagby didn't produce such a curve when he designed this MTM speaker.

 

[j_garcia]

It depends on how much SPL you're after. IMO, that AVR can handle them unless you sit further and have a large space and expect higher SPL. I had 5 4 ohm speakers on a Marantz 8300 and it was able to handle them at average volume, but when I wanted to turn it up, it was clear it didn't like it. That was with 5 of them though, just two of them in stereo was no problem. Marantz also states 6 Ohm minimum load even though it often gives a 4 ohm rating.

 

[TLS Guy]

This MTM speaker is very sensitive, rated at 91 dB at 2.83 volts. It should be easy to drive, and that Denon AVR is no slouch. You're probably being overprotective, as was Denon. But your question would be easy to answer by looking at an impedance vs. frequency curve for the speaker. Ask DIY Sound Group if they can provide one. I can't imagine that Jeff Bagby didn't produce such a curve when he designed this MTM speaker.

The problem is that there is absolutely no information on the drivers let alone the speaker. The woofers are custom.

If you are going to market to the DIY community then Jeff Bagby has to do a lot better than this.

There is sparse useful information on these, and so you can't really answer the OP's question. No idea if it will be prone to blow up the receiver or not.

 

[3db]

To the OP, if you see, 4ohms, does it tell you at what frequency? Also, does the kit provide you with the max/min phase angle ans at what frequency? I'm curious to know.

 

[DIY Junky]

I have a Denon 3808 and a 4520, I'd run 4ohm speakers but.... What's the sensitivity spec? How loud do you want them to play at what distance?

Front channels are 10feet at 30 Degrees from sweet spot . Volume levels when playing wave files and cds the denon volume level at 20. When playing vinyl on U-Turn record player with Ortofon 2M red moving magnet cartridge Denon volume level at 10. The sensitivity spec on kit is 91db-2.83v/1m. The woofers are Denovo 7" Hexcore the tweeters are Fountek NeoCD3.5H ribbons. I would have to say I play Loud at least 90 - 95 db and I should get a DB meter and be sure . And to get a good channel level set up on speaker levels . I love the denon and don't want to shorten its life span . Thanks for all your shared knowledge

 

[DIY Junky]

To the OP, if you see, 4ohms, does it tell you at what frequency? Also, does the kit provide you with the max/min phase angle ans at what frequency? I'm curious to know.

No detailed specs on kit I guess I could look up charts on drivers and tweeters

 

[Swerd]

No detailed specs on kit I guess I could look up charts on drivers and tweeters

The tweeter's details are here. Fountek shows no impedance vs. frequency curve, but the specs state a nominal impedance of 7 ohms. Most ribbon tweeters have essentially constant impedance across most of the audio range, and this tweeter probably is like most others. So any dips in impedance in this speaker are unlikely to be caused by the tweeter.

I've looked but found no graphs of frequency response or impedance for the Denovo Hexacore 7" woofer.

What we want to see is an impedance vs. frequency graph of either a woofer alone, or better yet, 2 woofers mounted in the MTM cabinet. Both impedance and response (loudness or SPL in dB) are often shown together in one combined graph. It could look something like the example below from an unrelated ported MTM speaker. The speaker's impedance (blue trace) reads in ohms with the impedance scale on the right side of the graph. The feature to look for is the lowest impedance across the frequency range. In this example, the low is greater than 4 ohms at about 150 to just above 200 Hz.

If your kit has a similar looking impedance curve, it could easily be driven by your Denon AVR without any problem.

 

[DIY Junky]

The tweeter's details are here. Fountek shows no impedance vs. frequency curve, but the specs state a nominal impedance of 7 ohms. Most ribbon tweeters have essentially constant impedance across most of the audio range, and this tweeter probably is like most others. So any dips in impedance in this speaker are unlikely to be caused by the tweeter.

I've looked but found no graphs of frequency response or impedance for the Denovo Hexacore 7" woofer.

What we want to see is an impedance vs. frequency graph of either a woofer alone, or better yet, 2 woofers mounted in the MTM cabinet. Both impedance and response (loudness or SPL in dB) are often shown together in one combined graph. It could look something like the example below from an unrelated ported MTM speaker. The speaker's impedance (blue trace) reads in ohms with the impedance scale on the right side of the graph. The feature to look for is the lowest impedance across the frequency range. In this example, the low is greater than 4 ohms at about 150 to just above 200 Hz.

If your kit has a similar looking impedance curve, it could easily be driven by your Denon AVR without any problem.

I looked for info on the 7"drivers and found nothing as well. I e- mailed DIY sound group for any info on the 7" drivers in this kit. Thanks again for all your help. Its seems like these are new drivers for them as well and are testing them out on us ? This kit has my eye and I can wait from more data . Maybe I will try to get a hold of Jeff Bagby for charts of finished speakers

 

[BoredSysAdmin]

As Swerd had mentioned above, with rated Sensitivity of 91db you have nothing to worry even with nominal 4ohm impedance and these Denons are more powerful than you think.