My Current Receiver and New Speakers

[Brian Alexander]

Hey everyone, first post and certainly won't be my last.

Right now, my current setup is a simple one: Energy Take Classic 5.1 speakers+sub, and a Denon AVR S510BT.

I recently was given a pair of ELAC Uni-Fi UB5s as a gift. I looked up the specs for these speakers, and they are 4 Ohm speakers, with a recommended input of 40 - 140 watts, and a 140 watt peak.

However, the Denon I currently have has its ratings listed as 70 WPC at 8 Ohms, 20Hz - 20kHz, 0.08% THD and 90 WPC at 6 Ohms, 1Khz, 0.7% THD. The minimum impedance is 6 Ohms.

So, a few questions:

1. Why is the frequency in the ratings different for the 8 Ohm (20 - 20k Hz) and the 6 Ohm (1khz) different?

2. I want to use these new speakers with this receiver, but am uncertain as to the lower impedance of the speakers. From what I can find online, the general consensus is that as long as I don't play the system too loud for too long, it will be okay. But is there a mathematical way of figuring out exactly how many watts my AV Receiver can safely provide into a 4 Ohm load given the ratings that are published for it?

3. I ask question 2 because if so, what happens if the power provided by the receiver can't safely get up to the speaker's recommended power? I'm pretty confident that won't be the case for the UB5s, but it's still a curiosity i have.

4. Are my assumptions correct that I can use the speakers as long as I don't blast the system too hard? From what I can tell the ratings are for safety test purposes, so as long as the receiver isn't running too hot and isn't clipping, i should be okay... right?

5. Finally, I'm looking at getting a new receiver. I was looking at the Denon X3300W, which does go down to 4 Ohmn loads. Any feedback on this model (or a better receiver in the same <$600-ish price range?)

I really appreciate any insights you all can provide, and look forward to getting all this hashed out.

Thanks!
Brian

 

[PENG]

Hey everyone, first post and certainly won't be my last.

Right now, my current setup is a simple one: Energy Take Classic 5.1 speakers+sub, and a Denon AVR S510BT.

I recently was given a pair of ELAC Uni-Fi UB5s as a gift. I looked up the specs for these speakers, and they are 4 Ohm speakers, with a recommended input of 40 - 140 watts, and a 140 watt peak.

However, the Denon I currently have has its ratings listed as 70 WPC at 8 Ohms, 20Hz - 20kHz, 0.08% THD and 90 WPC at 6 Ohms, 1Khz, 0.7% THD. The minimum impedance is 6 Ohms.

So, a few questions:

1. Why is the frequency in the ratings different for the 8 Ohm (20 - 20k Hz) and the 6 Ohm (1khz) different?

2. I want to use these new speakers with this receiver, but am uncertain as to the lower impedance of the speakers. From what I can find online, the general consensus is that as long as I don't play the system too loud for too long, it will be okay. But is there a mathematical way of figuring out exactly how many watts my AV Receiver can safely provide into a 4 Ohm load given the ratings that are published for it?

3. I ask question 2 because if so, what happens if the power provided by the receiver can't safely get up to the speaker's recommended power? I'm pretty confident that won't be the case for the UB5s, but it's still a curiosity i have.

4. Are my assumptions correct that I can use the speakers as long as I don't blast the system too hard? From what I can tell the ratings are for safety test purposes, so as long as the receiver isn't running too hot and isn't clipping, i should be okay... right?

5. Finally, I'm looking at getting a new receiver. I was looking at the Denon X3300W, which does go down to 4 Ohmn loads. Any feedback on this model (or a better receiver in the same <$600-ish price range?)

I really appreciate any insights you all can provide, and look forward to getting all this hashed out.

Thanks!
Brian

Sound like you should read some of the very well written articles right here on Audiohlics.com

Example: http://www.audioholics.com/audio-amplifier/power-manipulation-in-av-receivers

You may also search the FAQ section for answers.

Quick and short answers to your questions:

1. It is mostly marketing, the 1 kHz 6 ohm thing allows them to quote a higher power rating.
2. In general yes, also yes you can do some calculations but you can also try the online calculator linked below:
http://myhometheater.homestead.com/splcalculator.html
3. The calculator above will tell you how much power you need, if you push the receiver beyond what it is designed for, distortions will increase and if you keep pushing the unit will hopeful shut down to protect itself and the speakers.
4. Basically yes.
5. At the $600 price point for brand new with warratny, I can't see anything better than the X3300W.

The X3300W is rated for 4 ohm, but at reduced dynamic output capability. You could leave the setting at 8 ohm for maximum real world performance if you pay attention to your question# 4.

 

[Brian Alexander]

Thanks for the really informative and helpful post! Gave me the confidence to go ahead and hook them up to see what they sounded like.

When you say " 5. At the $600 price point for brand new with warratny, I can see anything better than the X3300W." are you saying it is a good option, or that anything else would be better?

I ask because with the S510 powering them, they don't really perform as I'd expect them to, especially considering I've heard these in a few different setups over the past year. My assumption is the S510 can't really give them enough power to really shine, so I definitely want to get a solid receiver that can handle 4 Ohm speakers. I'm still very new to this hobby/industry/field, but it's one that's really peaked my interest over the past year or so, and so i want a decent receiver that can handle 4 Ohm speakers well if I'm going to continue.

When you say reduced dynamic range, I'm guessing you are referring to the range of frequencies the receiver can "play" into the speakers at 4 Ohms?

 

[PENG]

Thanks for the really informative and helpful post! Gave me the confidence to go ahead and hook them up to see what they sounded like.

When you say " 5. At the $600 price point for brand new with warratny, I can see anything better than the X3300W." are you saying it is a good option, or that anything else would be better?

I ask because with the S510 powering them, they don't really perform as I'd expect them to, especially considering I've heard these in a few different setups over the past year. My assumption is the S510 can't really give them enough power to really shine, so I definitely want to get a solid receiver that can handle 4 Ohm speakers. I'm still very new to this hobby/industry/field, but it's one that's really peaked my interest over the past year or so, and so i want a decent receiver that can handle 4 Ohm speakers well if I'm going to continue.

When you say reduced dynamic range, I'm guessing you are referring to the range of frequencies the receiver can "play" into the speakers at 4 Ohms?

Sorry it was a typo, I meant "can't", fixed now. My comments on reduced dynamic range referred to the 4 ohm setting. To allow them to rate the AVR as 4 ohm compatible, they provided a 4 ohm setting that if selected, will limit the output voltage. That in turn would limit the power output (hence the dynamic range) because output power is proportional to the square of the output voltage. It is not a problem if you are not pushing your receiver near it's limit during the highest dynamic peaks typically found in action movies and some classical music.

You can choose to ignore the 4 ohm setting and leave it at the default (typically) 8 ohm setting (many people do). Again, it really depends on how much power you actually need for your applications. What did the online spl calculator tell you? It is not possible to be more specific without the following info:

- you distance from the speakers
- room dimensions LXWXH
- How loud you listen to, 85 dB is reference level by THX standard but that's often considered too loud for home use. It would be about as loud as you would hear in a movie cinema that follow THX standard.

 

[Mikado463]

Sound like you should read some of the very well written articles right here on Audiohlics.com

Example: http://www.audioholics.com/audio-amplifier/power-manipulation-in-av-receivers

interesting link PENG, thanks for posting up. I wouldn't touch any of those examples ..........

 

[Brian Alexander]

I'm not entirely sure how the SPL information would allow me to check up on some of these things, but here's the information I used to plug into the calculator and the information I got back:

Sensitivity: 85 dB. The calculator says 1W / 1M, although the spec sheet lists it as "Sensitivity: 85 dB at 2.83 v/1m"

Amp Power: 70 Watts. This is where I get confused. I'm giving 70 W as the rating for an 8 ohm load, but the speakers are 4. I don't have a 4 Ohm value. That's what I'm trying to calculate with question 2: How can I figure out how much the power supply in my receiver can (safely) deliver into a 4 Ohm load. Is it safe to assume that resistance has no impact on the loudness of a speaker at a given input power? IE: 70W of input will always be 70W, regardless if it's 4, 6, or 8 ohm, and thus produce the same SPL?

Distance: 9 ft

Speakers: 2 (I'm using more speakers, but only 2 are the Elacs, which are what I'm curious about.)

Speaker Placement (Choose 1):: Near a wall.

Results:

18.5 db Gain from amp
-8.8 db from distance
3 db gain from position (Reinforcement)
100.7 db SPL

SO, now I know the max volume I can produce... what can be done with this information?

As for my average listening volume, not too terribly loud. The room is about 22 x 10 which is split between the living room on one side and the kitchen/dining area on the other. This is in an apartment so I'm not blasting it too loud, but I am able to play it surprisingly loud without disturbing my neighbors. If 85 is movie theater, I can't imagine (based on the helpful table of loudness estimates on the calculator you linked) I'm in the 75 ballpark when i listen to it at the loudest comfortable level. Everyday listening would be around 65-70.

 

[PENG]

Sensitivity: 85 dB. The calculator says 1W / 1M, although the spec sheet lists it as "Sensitivity: 85 dB at 2.83 v/1m"

Amp Power: 70 Watts. This is where I get confused. I'm giving 70 W as the rating for an 8 ohm load, but the speakers are 4. I don't have a 4 Ohm value. That's what I'm trying to calculate with question 2: How can I figure out how much the power supply in my receiver can (safely) deliver into a 4 Ohm load. Is it safe to assume that resistance has no impact on the loudness of a speaker at a given input power? IE: 70W of input will always be 70W, regardless if it's 4, 6, or 8 ohm, and thus produce the same SPL?

For the so called 8 ohm nominal speakers, the sensitivity given in 1W/1m is the same as that given in 2.83V/1m. For the so called 4 ohm nominal speakers, if given in 2.83V/1m, you can convert the given sensitivity to 1W/1m by subtracting 3 dB, in order to use that calculator. So in your case, instead of entering 85 dB @ 2.83V/m, you should enter 82 dB.

Distance: 9 ft

Speakers: 2 (I'm using more speakers, but only 2 are the Elacs, which are what I'm curious about.)

Speaker Placement (Choose 1):: Near a wall.

Results:

18.5 db Gain from amp
-8.8 db from distance
3 db gain from position (Reinforcement)
100.7 db SPL

Your Denon is rated 75W, not 70W. Entering the relevant information, according to that calculator you would get about 98 dB from you sitting position at rated out of the Denon, two channel driven continuously. You did very well as you were only out by 2.7 dB.

SO, now I know the max volume I can produce... what can be done with this information?

As for my average listening volume, not too terribly loud. The room is about 22 x 10 which is split between the living room on one side and the kitchen/dining area on the other. This is in an apartment so I'm not blasting it too loud, but I am able to play it surprisingly loud without disturbing my neighbors. If 85 is movie theater, I can't imagine (based on the helpful table of loudness estimates on the calculator you linked) I'm in the 75 ballpark when i listen to it at the loudest comfortable level. Everyday listening would be around 65-70.

75 dB average is still good volume for a lot of people, for me anyway. In that case, your AVR can provide you with the THX standard 20 dB peak for movies, (75+20=95 dB) and still have 3 to 6 dB to spare. Basically that means on occasions you could push your Denon a little harder and listen to 78-80 dB average. If you can't live with that, then you need to upgrade your AVR.

 

[Brian Alexander]

Very informative stuff. I feel like I'm starting to understand more of these figures, measurements, specs, etc. more than before I posted, so thanks for that!


After listening to these more and making some adjustments to the crossovers and levels, I have started to like them more. It'll take me a few more days of listening and tinkering to really figure out what I think, but I'm slowly starting to warm up to them as i tinker and find what sounds most appealing to my ear.

I guess this might be a simple question but it's one I don't know: If I were to add the matching center channel (More on that below), would the same outputs from the previous calculations be the same? It's my understanding that the receiver has a common power supply for each channel's amps, so wouldn't that mean that running more 4 ohm speakers put more tax on the PSU to get the same SPL?

I ask because the current center I have is swallowed up by these. If I boost the levels on the center, it almost "screams" over the top of the Elacs. No matter what I've attempted I can't get the center channel to really "fit" correctly. When I get it dialed in for a particular song or genre, I switch to different music or a movie and it's totally off again, and there doesn't seem to be a happy middle-ground where I can really configure things to sound "all-around good". Given I'm still using the center channel from the take classics (3 inch woofer with 0.75 inch tweeter), I'm inclined to believe that my best bet is to get the matching center UC5.

 

[PENG]

I guess this might be a simple question but it's one I don't know: If I were to add the matching center channel (More on that below), would the same outputs from the previous calculations be the same? It's my understanding that the receiver has a common power supply for each channel's amps, so wouldn't that mean that running more 4 ohm speakers put more tax on the PSU to get the same SPL?

If you replace the take 5 center with the UC5 you are obviously pushing the envelope. You should still be fine with 75 dB average and 95 dB peak spl. You will be at the limit only during the highest movie peaks. To produce 75 dB average spl at 9 ft, your AVR output is less than 0.5W per channel.

To be clear, if you watch movies at or near reference level, you are going to need much more power than your entry level AVR can deliver. An entry level AVR can only serve you well if you sit close to them (you are) in a small to medium size room, and you don't listen to levels at or close to reference level. So if your listening habits and/or environment change, use that online calculator again to determine your new power needs.

 

[Brian Alexander]

Got it. This has been very informative. Thanks!

I'll grab the matching center and the X3300W sometime in the next month or two. I will be likely moving out of this apartment within the year to an actual house where I'll have more flexibility in placement and loudness. I l0oked more into the 3300 and like the fact it has preamp outputs for the future if i decide to run more power-hungry speakers. I'm not so concerned about it not having HEOS, so I think it'd be a good receiver to have and keep for a while, and expand with external amps if I end up needing more power down the road.\

Thanks so much for all the good information and assistance, Peng!