Setup (BI-Amp?)

sredmyer

I recently bought my first real HT setup. For my reciever I purchased the HK AVR 7300 (a refrub). I also bought the Onkyo DV-CP802 DVD/CD 6 disc changer. And finally for the speakers I bought Polks, Monitor 60's (for the front left/right), Monitor 30's (for the two surround (only 5.1 at first)) and a CS1 for the center and got the PWS10 sub for free. So that was my system. Now last night the wife wants to hear some XMas music (Mormon Tabernacle Choir). She really likes to feel this music (and well she should with this system). Well after only a few moments of playing the Halleuia chorus (at full volume) one of the monitor 60's blew a tweeter (literally threw the voice coil out). Having bought the speakers from local eletronics store I simply took them back and got replacements. Since the wife says she did not think the music was really that loud when she blew the 60's I though I could add another set of monitor 30's (now full 7.1) which would increase the sound level. So when I took the 60's back to be replaced I also bought another set of 30's. I don't think this added much as far as sound pressure (loudness) goes. So after that long intro here is the real question. Would I be better off to hook the 2 Monitor 60's up in Bi-Amp fasion? If so how would I do this and what exactly is Bi-Amp? Here is what I know...the Monitor 60's are rated at 200 wpc and The AVR 7300 is rated at 110 wpc to all seven channels (in 2 channel stereo it is 125 wpc). Based on this I suspect that the speaker was blown due to under driving and clipping/distortion. So if I hook them up bi-amp with the 2 extra surround (and return the extra 2 Monitor 30's) channels are they (the speakers) now getting a possible 220 wpc (110 wpc main amp + 110 wpc surround amp). If so will this extra power make a large difference in the volume level? Also how likely would I then be to blow the speakers the other way around (to much power)?

Any thoughts would be greatly appriciated,
Steve

Tour2ma

sredmyer wrote:

1. Well after only a few moments of playing the Halleuia chorus (at full volume) one of the monitor 60's blew a tweeter (literally threw the voice coil out).
2. Based on this I suspect that the speaker was blown due to under driving and clipping/distortion.
3. Also how likely would I then be to blow the speakers the other way around (to much power)?

1. Do you mean literally maximum volume as in can't go any higher?
2. If your answer to #1 was "yes", then I suspect you are correct.
3. If your answer to #1 was "yes", then very likely.

Seriously, maximum volume settings are justequipment and your ears. Turn it down some and live to hear another day. You have to be especially careful with a dynamic performance like the Hallelujah Chorus. If you crank up a soft passage, when the fortisimo comes it's boom time.

Your HK's volume scale is likely like -75 to +20 (or so). Stay on the "-" side and you'll be fine.

Merry Christmas... and Welcome to the Club...

HBombToo

welcome and I am ROFLOL. Did ya blow any light bulbs by chance. I could only wish my wife would allow me to turn it up that loud!

1/4twin

SuperDave

What a woman to turn it up that loud! Seriously though for most amps half way up will blow you out of the room unless you have some serious equipment..........

sredmyer

Tour2ma wrote:

1. Do you mean literally maximum volume as in can't go any higher?
2. If your answer to #1 was "yes", then I suspect you are correct.
3. If your answer to #1 was "yes", then very likely.

1. Yes I mean literally maxed out...She (the wifey) says she wants more (volume). This is why I am asking about Bi-Amp hook up. First will it accomplish the goal of more volume for the wifey while at the same time providing that more volume with the control still on the '-' (negative) side and thereby provide some measure of protection for the speakers? Second how does one wire the reciever and speakers for this 'Bi-Amp'? And finally any ideas on how to set th Harman Kardon AVR 7300 up for this?

2. So if I read your response correctly you also suspect that the speakers were blown due to under driving...is this correct?

3. As pondered above...do you suppose that I might achieve the volume she (the wifey) is looking for with this added power at a lower actual volume control position (still on the '-' side) and thereby reduce the level to which she 'cranks' it?

Thanks for the welcome. If anyone outthere has a HK AVR 7300 and would like to share insight on properly setting it up, I'd love to hear from ya.

BTW, just for the record this cranking it up problem is not likely to get any better after the holidays. Once her holiday spirit has left she will certainly be wanting to hear Metallica, STP, Nine Inch Nails, etc. and want it loud.

Now in all fairness to the wifey...I like it loud too (my taste tend towards clasic rock though)...she is just the one who actually blew the speakers.

Steve

sredmyer

SuperDave wrote:

What a woman to turn it up that loud! Seriously though for most amps half way up will blow you out of the room unless you have some serious equipment..........

I believe blown out of the room is exactly what she is looking for.

Tour2ma

1. Bi-amping is not going to generate that kind of continuous volume. Your 7300 has pre-outs, so you can run an external amp. Whether or not you can bi-amp using the HK's main amp channels depends upon whether it's designed to send the signal both internally and externally at the same time. Most do this, but some don't.

2. Yes, underpowering... clipping such as may have never been seen in the history of audio as witnessed by your tweeter trying to run away from home.

3. Doubtful... I'm not sure what your wife had been listening to (other than maybe 747's on take-off), but somewhere along the line sound quality has to get in the mix. Clean and slightly less loud beats louder and distorted in most anyone's book...

sredmyer

Tour2ma wrote:

1. Bi-amping is not going to generate that kind of continuous volume. Your 7300 has pre-outs, so you can run an external amp. Whether or not you can bi-amp using the HK's main amp channels depends upon whether it's designed to send the signal both internally and externally at the same time. Most do this, but some don't.

2. Yes, underpowering... clipping such as may have never been seen in the history of audio as witnessed by your tweeter trying to run away from home.

3. Doubtful... I'm not sure what your wife had been listening to (other than maybe 747's on take-off), but somewhere along the line sound quality has to get in the mix. Clean and slightly less loud beats louder and distorted in most anyone's book...

My wife says (and I agree although I am admittely no audiophile) that before the speakers blew the system sounded awsome...no (perceptable) distortion crisp and clear.

Based on some of the post here I am wondering if I have the damn thing hooked up wrong. From what I have read this HK is an awsome powerful beast, and these Polk speakers should be more than sufficient in the small room we have them in. But like the wife says (and again I concur) at times it just needs more. You can almost talk (not screaming) over it when it is at 0db on the volume control and there should be more.

Steve

Tour2ma

It's possible that some setting is limiting range (AVR's have "night" or another termed setting), but ones I know of are compression oriented.

Again, if the dyanmics of the recording contributed, then it might sound good up until the failure occured, but I don't see how.

With these spec's the 7300 is not weak in the knees, but hardly a brute. The HCC is very nice, but it's a total and not per ch. Also while 37 amperes per ch is decent, it's not clear that HCC is all available in 2 ch mode. And in the 7 ch mode power rating no claim is made about all channels driven simultaneously, because they are not.

Stereo Mode Continuous Average Power (FTC) per Channel :
125 Watts per channel @ <0.07% THD, 20Hz – 20kHz, both channels driven into 8 ohms
Seven-Channel Surround Modes, Power per Individual Channel :
Front L & R Channels : 110 Watts per channel @ <0.07% THD, 20Hz – 20kHz into 8 ohms
Center Channel : 110 Watts @ <0.07% THD, 20Hz – 20kHz into 8 ohms
Surround Channels (L & R Side, L & R Back) : 110 Watts per channel @ <0.07% THD, 20Hz – 20kHz into 8 ohms
High Instantaneous Current Capability (HCC) : ±75 Amps

All that said, if you want to give bi-amping a try, other HK AVR owners have added external HK amps for their mains with good satisfaction. And you do not have to restrict yourself to HK amps...

sredmyer

Tour2ma wrote:

It's possible that some setting is limiting range (AVR's have "night" or another termed setting), but ones I know of are compression oriented.

This setting is not turned on.

Tour2ma wrote:

Again, if the dyanmics of the recording contributed, then it might sound good up until the failure occured, but I don't see how.

The recording is an old CD and does have alot (atleast I think it is alot) of audible hiss.

Tour2ma wrote:

With these spec's the 7300 is not weak in the knees, but hardly a brute. The HCC is very nice, but it's a total and not per ch. Also while 37 amperes per ch is decent, it's not clear that HCC is all available in 2 ch mode. And in the 7 ch mode power rating no claim is made about all channels driven simultaneously, because they are not.

Not sure if I fully understand all these specs (in fact I'm fairly sure I do not) but the HK web site or the owners manual (do not remeber where I read it) says that the AVR 7300 has seven identical amplifiers. Wouldn't that mean that the HCC of 75 would be the same for all seven channels? Also one of the reasons I bought this particular unit (aside from the sound which I feel is nothing short of amazing) was this little tid bit I read on the HK web site.

Question:
Why are Harman Kardon amplifiers so much more powerful than amplifiers with the same power ratings that are made by other companies?


Answer:
A Harman Kardon 50-watt amplifier will sound better, louder and cleaner than most 100-watt amplifiers from other companies. The reason is very simple. We give "true" wattage ratings, and our amplifiers utilize something called High-Current Capability (HCC). Please see the comparison below for further explanation. Other companies (100 watts):
Many companies have found new, convenient ways to get "big" wattage ratings on their amplifiers. They may take one frequency or tone (1kHz) and push it through one channel of amplification. This way the power supply only needs to supply power to one tone and one channel (no one listens to one tone through one speaker). This is not a difficult task for a power supply, so you get a nice, high rating like 100 watts. Now let's feed that one tone (1kHz) into 2 channels. Now the power supply has to supply power to 2 channels. The wattage rating is drastically reduced. Now let's take that one tone and make it ALL tones (pink noise). The power supply now has to supply power to all frequencies in both channels. Again, the wattage rating is drastically reduced. Now, your 100-watt amp is suddenly 50 watts (approximately).

Let's take it one step further. When you turn the amp up and begin to average the 50 watts of power, what happens to all of the dynamics/peaks in the sound? It can't get any louder, because the amp has hit its "ceiling," so the sound gets "clipped." The human ear typically can?t hear this clipping because peaks pass by so quickly but, nonetheless, the dynamics are gone.

Our amplifiers (50 watts):

We still rate our amplifiers the old-fashioned way - all frequencies with both channels driven. So "50 watts" is 50 watts. Twenty-five years ago, a 50-watt amp was very powerful. These days you can go to a store and hear a "300 watt" receiver and it won't impress; it lacks dynamic punch.

Now let's take it that extra step. When you turn the amp up and begin to average the 50 watts of power, the amp still needs to put out much more power every time a snare drum, triangle, or movie dynamic (e.g., hand slapping a face) hits. Our amps are able to instantaneously put out 20-100 amps (depending on the model) of high current to the speakers, allowing those dynamics to come through loud and clear, without any distortion. This brings the overall decibel average up, making it seem even louder that 50-watts.

sredmyer

I read somewhere that some speakers are more efficent than others. Could this be part of the problem here. Are the polk speakers not very efficent. I remeber from long ago (in a different life) when Cerwin-Vega speakers were said (atleast in some circles) to be the most efficent speakers around. The same amp would sound much louder through a pair of CW's than through most anything else. My question to this is; what is the cost of that efficency? Is it accuracy? Is there a speaker efficency rating? If so how would these Polks rate?

Again thanks to all (especially Tour2ma) for all the insight.
Steve

Tour2ma

7 ch's, but only one transformer, thus the 75 ampere limit...

HK may be more rigorous than many AVR manufacturers in rating their amp sections as the FAQ you cite states, but what it states is: "...all frequencies with both channels driven", and both is not all.

Not trying to slam your AVR, just being realistic.

Is there a sub in the mix you have not mentioned? If yes, are all the spekers set to small? If not, shifting the bass duties below 60 or 80 Hz to the sub can unload the AVR considerably.

sredmyer

Tour2ma wrote:

7 ch's, but only one transformer, thus the 75 ampere limit...

So each amp does not have its own transformer...Lerning alot here.

Tour2ma wrote:

HK may be more rigorous than many AVR manufacturers in rating their amp sections as the FAQ you cite states, but what it states is: "...all frequencies with both channels driven", and both is not all.

Again I took the fact that there were seven identical amps to mean that all channels were driven equally believing that it is the amp that does the driving. Is this not true?

Tour2ma wrote:

Is there a sub in the mix you have not mentioned?

Yes there is a sub...the PWS10 (which came as a freebee with the speakers) but after some reading here I realize I may want to upgrade that soon.

Tour2ma wrote:

If yes, are all the spekers set to small? If not, shifting the bass duties below 60 or 80 Hz to the sub can unload the AVR considerably.

I will try this. How will "unloading the AVR" help in the sound level?

Tour2ma

A great deal of the power requirements reside with the lower frequency information. Any portion of that that you reassign to your sub is no longer supplied by your AVR. You still cannot near your AVR's maximum volume setting, but you can go a bit higher and the sound quality will stay "cleaner".