Harman Kardon volume level difference

[fizzz]

Hi,

i have a HK 7550HD and i noticed that when i play music on 7 channels (in 7 channel stereo mode), i noticed that the two front speakers are always louder.

I verified all level settings and crossover settings, and they are all equal!

Has someone ever noticed that on HK amp?

BTW , i have a HK AVR-745 and AVR-645 that does the exact same thing.
Is that an explanation?

Because on paper, it is supposed to be 7 x 110w equal channels, so i really don't understand.

To correct my problem i crank up a bit my back and surround speakers, but i find it weird to have to do that.

Comments welcomed... i want to understand! lol

Of course, all my 6 speakers are the same.
I emailed HK about that, but obviously, i didn't received anything from them.

Thanks.

 

[PENG]

Hi,

i have a HK 7550HD and i noticed that when i play music on 7 channels (in 7 channel stereo mode), i noticed that the two front speakers are always louder.

I verified all level settings and crossover settings, and they are all equal!

Has someone ever noticed that on HK amp?

BTW , i have a HK AVR-745 and AVR-645 that does the exact same thing.
Is that an explanation?

Because on paper, it is supposed to be 7 x 110w equal channels, so i really don't understand.

To correct my problem i crank up a bit my back and surround speakers, but i find it weird to have to do that.

Comments welcomed... i want to understand! lol

Of course, all my 6 speakers are the same.
I emailed HK about that, but obviously, i didn't received anything from them.

Thanks.

Same level setting does not mean each speaker will sound equally loud from your listening position because the speakers are in different locations. You have to equalize them manually using the level settings and a sound level meter, or just run the AVR/Prepro's automatic setup program. Even after that, if you sit in a different position they again would not all sound equally loud to you.

 

[mtrycrafts]

...

I verified all level settings and crossover settings, and they are all equal!

Welcome.

How did you verify this?

BTW , i have a HK AVR-745 and AVR-645 that does the exact same thing.
Is that an explanation?

Could be if you didn't level match the channels with the internal test tones and an sound pressure meter as Peng mentioned.

Because on paper, it is supposed to be 7 x 110w equal channels, so i really don't understand.

Well, that means that they can put out that much power from each channel as needed but not that power at the same instant to the 7 channels.

To correct my problem i crank up a bit my back and surround speakers, but i find it weird to have to do that.

Most likely because you didn't level match all channels properly with that spl meter.

 

[fizzz]

Thanks for your comment, but it's not a position question. If i stand 3 feet away in front of each 6 speakers, the two fronts are clearly louder than the back and surround. I wouldn't have post that question if i was listening to the system from my sofa, i understand that the distance and orientation change, but it that case, that's not it.

I even used my iphone with a level meter at 3 feet away, and it sees a difference, so it's not in my head lol

I seriously doubt that the circuitry design is in cause, since on HK amplifier, the front speaker connectors, are always bigger than the rear and surround connectors. Even if it's sound stupid, that is the only explanation that i see... If the exact same power would be distributed equally everywhere, why would they put smaller connector on back channels? ... (just guessing lol)

 

[anamorphic96]

Thanks for your comment, but it's not a position question. If i stand 3 feet away in front of each 6 speakers, the two fronts are clearly louder than the back and surround. I wouldn't have post that question if i was listening to the system from my sofa, i understand that the distance and orientation change, but it that case, that's not it.

I even used my iphone with a level meter at 3 feet away, and it sees a difference, so it's not in my head lol

I seriously doubt that the circuitry design is in cause, since on HK amplifier, the front speaker connectors, are always bigger than the rear and surround connectors. Even if it's sound stupid, that is the only explanation that i see... If the exact same power would be distributed equally everywhere, why would they put smaller connector on back channels? ... (just guessing lol)

Sounds like the main left and right are more efficient than the other speakers. So if the levels are equal and not calibrated with an SPL meter it makes perfect sense the mains are louder than the other channels. If they are more efficient they produce more sound pressure with less power.

What speakers are you using ?

 

[M Code]

Thanks for your comment, but it's not a position question. If i stand 3 feet away in front of each 6 speakers, the two fronts are clearly louder than the back and surround. I wouldn't have post that question if i was listening to the system from my sofa, i understand that the distance and orientation change, but it that case, that's not it.

I even used my iphone with a level meter at 3 feet away, and it sees a difference, so it's not in my head lol

I seriously doubt that the circuitry design is in cause, since on HK amplifier, the front speaker connectors, are always bigger than the rear and surround connectors. Even if it's sound stupid, that is the only explanation that i see... If the exact same power would be distributed equally everywhere, why would they put smaller connector on back channels? ... (just guessing lol)

7 Channel Stereo is referred to as Party mode..
If the L/R front channels are louder when in this mode but not the other modes then the DSP software is balanced that way. Don't understand your comments about the 7550HD speaker output connectors, ALL channels are the same size/type...

For your info..
The 7500HD does have separate level settings for each source input mode so you may want to go in and decrease down slightly the front L/R channels...

Just my $0.02..

 

[mtrycrafts]

Thanks for your comment, but it's not a position question. If i stand 3 feet away in front of each 6 speakers, the two fronts are clearly louder than the back and surround. I wouldn't have post that question if i was listening to the system from my sofa, i understand that the distance and orientation change, but it that case, that's not it.

I even used my iphone with a level meter at 3 feet away, and it sees a difference, so it's not in my head lol

I seriously doubt that the circuitry design is in cause, since on HK amplifier, the front speaker connectors, are always bigger than the rear and surround connectors. Even if it's sound stupid, that is the only explanation that i see... If the exact same power would be distributed equally everywhere, why would they put smaller connector on back channels? ... (just guessing lol)

I don't think you answered the question on how you level matched at the primary listening position all channels with the receiver's internal test tones, not music, and used a credible SPL meter, not you iPhone program app.

So far as I can determine, you didn't do it properly yet hence what you are measuring.

 

[PENG]

I wouldn't have post that question if i was listening to the system from my sofa, i understand that the distance and orientation change, but it that case, that's not it.

I even used my iphone with a level meter at 3 feet away, and it sees a difference, so it's not in my head lol

So you might have eliminated distance not being the issue but "position" of a speaker is much more than just the distance from your listening position. As you said, "orientation" of each of your speakers are not the same, i.e. how they are angled, how they interact with the surrounding walls, ceiling, furniture etc. You cannot expect them to sound equally loud just by feeding them with the same power and signal and be at the same distance of 3 ft from them, not in most rooms anyway.

As mtrycrafts has suggested, use the AVR's internally generated tone and a sound level meter to do your level matching manually or let the AVR do it automatically.

why would they put smaller connector on back channels? ... (just guessing lol)

You mentioned models 645 and 745, I find it hard to believe those higher end models would offer smaller connectors for the surround channels. When I can spare a moment I will check out their manuals.

 

[fizzz]

anamorphic96 ... to answer your question, for the moment, my 6 speakers are JBL Stadium + JBL Center (for center)

I put my HK in 7 channel stereo mode when i have a party here, so there is no fixed listening position... for partying, i want the same level on all 7 channels. To do that, i had to set surround and back channel level at +4dB (front speakers being 0dB)...

BTW, just as a matter of fact, yesterday night, i listened to music ( a little too loud i think lol RATM!) ... my tweeters on both front speakers just blown... it will cost me 8.56$ each to replace them...

But that just confirmed that there is more power on the two fronts channels speakers than the others, since the others didn't toast, and they were +4dB.

I seriously doubt that it is not true that it is 110 watt equally distributed on 7 channels.

 

[fizzz]

Like i said, my AVR-645 , and AVR-745 did the exact same thing...

I'm just surprised that nobody else ever noticed that on their HK amp.

before chrismas, i was looking to (maybe ) buy an Emotiva XPA-5,
so i think i will go that way... i plan to buy two emotiva XPA-5, and drive my 7 channel from them, and 3 other speakers in trhe house since i will have 10 channels.

 

[PENG]

anamorphic96 ... to answer your question, for the moment, my 6 speakers are JBL Stadium + JBL Center (for center)

I put my HK in 7 channel stereo mode when i have a party here, so there is no fixed listening position... for partying, i want the same level on all 7 channels. To do that, i had to set surround and back channel level at +4dB (front speakers being 0dB)...

BTW, just as a matter of fact, yesterday night, i listened to music ( a little too loud i think lol RATM!) ... my tweeters on both front speakers just blown... it will cost me 8.56$ each to replace them...

But that just confirmed that there is more power on the two fronts channels speakers than the others, since the others didn't toast, and they were +4dB.

I seriously doubt that it is not true that it is 110 watt equally distributed on 7 channels.

I suggest you try the following hook up just to erase some doubts.

1. Connect your front L/R speakers to the HK AVR's surround L/R channel outputs.
2. Connect your surround L/R speakers to the HK AVR's front L/R channel outputs.
3. Listen to the system in 7ch stereo mode again and see if the surround L/R channels now sound louder to you. Better still, use your SPL meter to take readings for before and after swappng the feeds to the speakers.

Lastly, you mentioned the front channels speaker output connectors (binding posts) are bigger than the surround channels? Which HK model are you talking about? As far as I know the 645 and 745 and even the lower models all have binding posts fo the same type and size for all 7 channels.

Thanks

 

[mtrycrafts]

I suggest you try the following hook up just to erase some doubts.

1. Connect your front L/R speakers to the HK AVR's surround L/R channel outputs.
2. Connect your surround L/R speakers to the HK AVR's front L/R channel outputs.
3. Listen to the system in 7ch stereo mode again and see if the surround L/R channels now sound louder to you. Better still, use your SPL meter to take readings for before and after swappng the feeds to the speakers.

...

Thanks

That will tell us something for sure. I also wonder how well the level is matched inside the receiver for that mode of operation.

 

[PENG]

That will tell us something for sure. I also wonder how well the level is matched inside the receiver for that mode of operation.

The manual for the 645 just say "send the same signal" but it does not say the same output level. It is a good question for HK tech support. I don't use that mode but last time I tried it just for fun I didn't pay much attention as like the OP I assumed the output to all 7 channels would be the same, no reason to believe otherwise, until now..

 

[fizzz]

About the size of the connector, i made a mistake... on the 745 and 7550HD , it is the same size for all connectors... but on my 645, it was a bit smaller...

I noticed in my avr-745's menu, that when you change the size of the speaker setup, in the menu, it's written "MAIN" beside of the front channel...

and if i configure front as small speaker and back as large speaker (Send all frequency), then "Main" is written beside the back speaker ...

as if the first Large speaker in the setup, become "Main"

But in the 7550HD, the menu has changed a lot, and i don't see that anywhere.

My Final test will be to mesure with my oscilloscope directly on the speaker wire, with a constant sound... i'm too curious to really know.

But BTW, i already tested to exchange my back and front speaker, with the same result, and as you probably know, my 6 speakers are the same JBL Stadium.

 

[timoteo]

Why did you say that the main speaker terminals are larger than the other speaker terminals? Because i looked up the 755HD & thats a nice receiver with all the terminals the same. The only receivers that do the larger (5way) main posts vs the small (push) plugs are the entry level avrs. They do this to save money & keep the price low. It doesnt change the power to the speakers.

Are you sure you have the 755HD?

Make sure you do because you need Pre-Outs to hook up external amps. The 755HD does have Pre-Outs but the lower models with the different size terminals most likely wont.

Not sure you need 2 XPA-5 amps. Those JBL-Stadiums are 8ohm nominal with a 91dB rating so they arent hard to drive. They are rated for 225watts RMS so the XPA's 200watts will work fine but id be concerned with why the tweets are blowing.

How high was the master volume when they blew?

 

[fizzz]

Hi Guys,

i finally made my test with the oscilloscope to confirm what i talked about in this thread.

In the configuration menu, I did put all the 7 channels equal to 0dB,
and all 7 speakers as Large,
after, i made a constant tone with audacity, a steady 90 seconds of 40Hz tone.
My Master volume at @ -20dB

So, on the rear channel, i read on the scope a peak-to-peak voltage of 255mV.

On the front channel, i could read on the scope a peak-to-peak voltage of 665mV.

So, that confirms that in 7 channel stereo mode, it is not the same power everywhere. Not at all.

On the scope, just for fun, i tried to on the front channel, turn down the volume -8dB (from -20dB to -28dB) , and at -28dB i have the same voltage as the rear channel. Crazy, eh?!

I'm glad that it wasn't in my head, but i bit disapointed,
i really love that amp, but i would really prefer having a 7 channel mode equally distributed, for party.

If i compare the sound of the 7550HD and an XPA-5, is that about the same quality ? (of course i know that XPA-5 is more powerful, but about the sound itself ?)

Thank you all...

 

[mtrycrafts]

Hi Guys,

i finally made my test with the oscilloscope to confirm what i talked about in this thread.

In the configuration menu, I did put all the 7 channels equal to 0dB,
and all 7 speakers as Large,
after, i made a constant tone with audacity, a steady 90 seconds of 40Hz tone.
My Master volume at @ -20dB

So, on the rear channel, i read on the scope a peak-to-peak voltage of 255mV.

On the front channel, i could read on the scope a peak-to-peak voltage of 665mV.

So, that confirms that in 7 channel stereo mode, it is not the same power everywhere. Not at all.

On the scope, just for fun, i tried to on the front channel, turn down the volume -8dB (from -20dB to -28dB) , and at -28dB i have the same voltage as the rear channel. Crazy, eh?!

I'm glad that it wasn't in my head, but i bit disapointed,
i really love that amp, but i would really prefer having a 7 channel mode equally distributed, for party.

If i compare the sound of the 7550HD and an XPA-5, is that about the same quality ? (of course i know that XPA-5 is more powerful, but about the sound itself ?)

Thank you all...

Well, that is an interesting result indeed. By chance you tried anotehr frequency to measure and see if the same holds true?
I wonder what other receivers would do in this condition. Maybe it is a processor issue, not an amp section in the receiver as the amp section just responds to the input voltage to it.

 

[96cobra10101]

 

[fizzz]

Oh, you can search words on youtube... good... but pretty much useless