new amplifier

[mulester7]

When you use "differential" signaling you typically get greater noise immunity
than with a "single ended" signal.

So if you have your amp, say 10 feet away from your processor, you
might benefit from a cleaner signal since your rca cable would be more
suspectable to noise introduced with the length.

P.S. I am really digging 4000 Watts of clean Audio Amplification

.....I see, TDeluce....so XLR inputs are, let's say, vital, with signal carrying cables coming to the amps from across the room.....three feet or so is fine to not have XLR inputs on the amp....the XLR's would have to be lower impedence inputs than the unbalanced inputs, so, a short length of cable would be even better through XLR's?....forget it, WmAx says 12 feet down without XLR inputs is inaudible....so I would say three feet is overkill by both standards.....

.....next topic....I saw a commercial tonight for one those jeep type vehicles....they said with every one sold, they would give you a free wench....hmmmm, a free wench.....like what we all need is another woman....buddy, listen, if they don't think one woman is enough to put you under, I need to line them up with my ex....after we split, she fell in love with one guy's airplane that he earned his living with, and his credit rating....she amassed 27 thousand in charges in about four months, and he left expense money whenever he flew out....she had clothes, two furs, shoes, one leather jacket that went about a thou, along with a couple of others, perfume after perfume, and high-dollar kitchen appliances stashed all over town, haha....true happening....you know, even though you don't care who's with her now, it's hard to feel sorry for whoever takes up with your ex, ya' know?.......

.....I'm up late tonight cleaning up the ole' theater in the storage-dungeon....Jermain Taylor fights tomorrow night on HBO in a rematch with Bernard Hopkins, and a small crowd is coming over....a couple of them said they would chip in on the price of the pay-per-view event, and I said don't worry about it....that's correct, haha......

.....TDeluce, there's no doubt in my mind you're loving that amp.....

 

[rolyasm]

5 channel earthquake?

Wow. Where are you seeing the 5 channel Earthquake for $1399.00. Sign me up. Do you have a web site?
Roly

 

[tdeluce]

Wow. Where are you seeing the 5 channel Earthquake for $1399.00. Sign me up. Do you have a web site?
Roly

It is the three channel version:

http://www.federalstereo.com/federalstereo/earsouncin3.html

 

[rolyasm]

earthquake 3 channel

Oh, now I understand. That is why I was confused. I can get the three channel for $1,250 shipped. I couldn't understand how it could be cheaper than my prices.
Roly

 

[tdeluce]

Oh, now I understand. That is why I was confused. I can get the three channel for $1,250 shipped. I couldn't understand how it could be cheaper than my prices.
Roly

That is a great price. Is it from an authorized Earthquake Sound dealer?

http://www.earthquakesound.com/home locator.htm

 

[rolyasm]

Ya, it is from an authorized dealer. Me.
I am a dealer for many lines like Denon, Earthquake, Adcom, Clark Tactile and then I get distributor prices for many other items like Energy, Mirage, Onkyo, Integra, Pioneer, JVC, Panasonic, and a bunch more. That is why I was so impressed since I thought it was a 5 channel amp below even dealer cost. I don't see my name on Earthquakes list, so I will have to call them Monday to remedy that. The name of my company is Peak Sound in Utah. You can look for it on the list this week. They must not have updated their system in a long time since I have been a dealer for about 6 months.
Roly

 

[mulester7]

Ya, it is from an authorized dealer. Me.
I am a dealer for many lines like Denon, Earthquake, Adcom, Clark Tactile and then I get distributor prices for many other items like Energy, Mirage, Onkyo, Integra, Pioneer, JVC, Panasonic, and a bunch more. That is why I was so impressed since I thought it was a 5 channel amp below even dealer cost. I don't see my name on Earthquakes list, so I will have to call them Monday to remedy that. The name of my company is Peak Sound in Utah. You can look for it on the list this week. They must not have updated their system in a long time since I have been a dealer for about 6 months.
Roly

.....so Roly, ole'-Buddy-ole'-Pal, could a fellow Audioholic get the Earthquake 3 channel amp from you for around $1250 and it have full warranty?....would a fellow Audioholic need to contact you with an inhouse Personal Message?......

.....edit....remember that signature that said, "ask not, get not"?.....

 

[rolyasm]

earthquake

Hmm.... I dunno. After reading this thread I get the impression you don't like power. hehe. Technically, my dealer contract forbids me to sell things over the internet. So unless you are willing to pick up a really heavy phone and call me, or email me, I guess you are out of luck. Check your private messages. Also, I don't know how Audioholics feels about business in their threads, so we will avoid it until I find out otherwise. I know I contacted them and they said to advertise would cost something, I never found out what. Also, since I am a dealer and a distributor, I think I can't advertise distributor things, only direct dealer things. So confusing. But ya, I'll hook you and anyone else up with whatever deals I can find, not online of course.
Roly

 

[xboxweasel]

More watts do not make a system sound better. If your speakers are reasonably efficient you can turn up your speakers to ear shattering levels without clipping.

It has nothing to do with clipping. Trust me. I got 3 amps running my 7.1. And I have very efficient speakers. But the amps make it better. I get much better dynamics from my amps than my receiver. I'll never go back.

 

[jaxter]

Power to the people

The normal power requirements for acommon 89 dB sensitivity rating is very minimal. The average power usage would be somewhere in the area of 1 to 2 watts. That being said, that is an exteme over simplification of the power requirements for a loudspeaker.
Music is dynamic and not steady state. RMS values are the average rated power output. It is a relative measure of the power that the amplifier is capable of. The peak power required to accurately reproduce a peak can be as much as 20-30 dB higher than the average signal. A 20 dB peak requires 100 times the power and a 30 dB peak requires 1000 times as much power as your starting point.
I am keeping this very simple and glossing over the technical details. My point is that lots of good clean power, especially in headroom capability is always a good thing when it comes to good fidelity.
Just so no one thinks that I am exagerating anywhere, to clarify one more point;
Most pop recordings only have about 15 dB of dynamic range. Although many good recordings have closer to 20-25 dB of dynamic range and some classical recordings go so far as 60-70 dB of dynamic range. In most cases the majority of recordings will not exceed 20dB of dynamic range.
I have never really checked to see what is used in film post production recordings so I cannot really speak to that with any knowledge or credibility.

 

[mtrycrafts]

The normal power requirements for acommon 89 dB sensitivity rating is very minimal. The average power usage would be somewhere in the area of 1 to 2 watts. That being said, that is an exteme over simplification of the power requirements for a loudspeaker.
Music is dynamic and not steady state. RMS values are the average rated power output. It is a relative measure of the power that the amplifier is capable of. The peak power required to accurately reproduce a peak can be as much as 20-30 dB higher than the average signal. A 20 dB peak requires 100 times the power and a 30 dB peak requires 1000 times as much power as your starting point.
I am keeping this very simple and glossing over the technical details. My point is that lots of good clean power, especially in headroom capability is always a good thing when it comes to good fidelity.
Just so no one thinks that I am exagerating anywhere, to clarify one more point;
Most pop recordings only have about 15 dB of dynamic range. Although many good recordings have closer to 20-25 dB of dynamic range and some classical recordings go so far as 60-70 dB of dynamic range. In most cases the majority of recordings will not exceed 20dB of dynamic range.
I have never really checked to see what is used in film post production recordings so I cannot really speak to that with any knowledge or credibility.

I bet people will get confused when you combine dynamic range of classical, 60-70dB and average recorded level and peaks. While that classical recording has such high dynamic range, its average and peak may not be that different.

 

[mtrycrafts]

It has nothing to do with clipping. Trust me. I got 3 amps running my 7.1. And I have very efficient speakers. But the amps make it better. I get much better dynamics from my amps than my receiver. I'll never go back.

If it has nothing to do with clipping and you don't or didn't run your receiver into clipping, then these added amps just cannot make a difference.

 

[Dan Banquer]

New Amp

If it has nothing to do with clipping and you don't or didn't run your receiver into clipping, then these added amps just cannot make a difference.

I just don't know how you could possibly say that unless you were there and took some measurements. In addition, you would need to do a thorough measurement of the receiver power amp section, and at least some peak spl readings of the room in question.
I am rather skeptical of most receiver power ratings unless they were tested by Audioholics.
d.b.

 

[Doug917]

Sorry, but anyone who tells you amplifiers with good wattage (200 Watts and above) don't make a difference has not heard this setup theirself or has something wrong with their hearing. I have easily heard the difference and will never drop below 200 Watts per channel again.

 

[tdeluce]

Sorry, but anyone who tells you amplifiers with good wattage (200 Watts and above) don't make a difference has not heard this setup theirself or has something wrong with their hearing. I have easily heard the difference and will never drop below 200 Watts per channel again.

Try watching 'War of the Worlds' at reference level and you might up that ante a bit

 

[Eric Apple]

Power does matter..

Not a big surpise, when the music is loud the power does matter. Just didn't know it mattered this much.

I pulled out my oscilloscope & SPL meter and took a few measurements. With music playing pretty darn loud, the reading was peaking at 103db on C weighting fast response peak hold, on a digital RS sound meter, at about 15 ft. Nice way to go deaf I guess.

The scope was showing about 32 volts p-p signal most of the time on the main l/r speakers. That's (32/2)^2/4=64 watts visually averaged peak into my 4 ohm speakers. I can't calculate the RMS value because the signal's not a sine wave and I don't have really fancy scope. RMS is probably about 25% of that peak value. There was also running with a sub crossed over at 80hz.

When the quick snap of some hand claps (sounds like finger snaps or something) hit in the source material the scope showed about 75 volts p-p, or (75/2)^2/4 = 352 peak watts.

So that backup power really does matter, it's extreamlly short duration I observered here at about .5ms (.0005 seconds). But, none the less that much power was required to avoid clipping.

The amp tested was an outlaw 7125 (rated continuoius 190w rms into 4 ohms), the test music track was Black Eyed Peas, Monkey Business, PumpIt.

I have no idea what other amps or receivers are capable of, but this measurement shows having dynamic reserve power does matter if your playing it loud. A big "duh" here - a bigger amp plays louder without distorting.

At lower volume levels around 85 db (fast response c weighting, peak hold) it's not going to matter which amp (wthin reasonable power levels). At this volume level (what sounds pretty good to me), visually average peak power was about 6 v p-p, or (6/2)^2/4=2.25 avg watt, with peaks of about 14 volts p-p when the claps hit, or (14/2)^2/4=12 watts.

Keep in mind there was a sub in the picture, with no sub I don't know what the readings may have been without one handling the bass. I'd guess I would loose headroom due to the transient snaps having to ride a top the low freq material.

So just about any receiver will play this song at a nice listening level. Wanna get louder, you need more power very quickly. 85 db is pretty satisfying to me, but not what I call loud. The 103 db was really way too loud and about the limit of the amp in the test setup.

P.S. I agree WOTW rocked the house!! Great LFE and other effects really made it fun to experience played loudly. The movie was slightly blah, but where the first ship comes out of the hole in the street, better hang on cause it really rocks !! The audio effects made it ton's of fun.

EDIT: Someone mentioned too add test speaker ratings & room size. Here they are:
Sensitivity: 89 dB/2.83 volts/meter
Impedance: 4 ohms, 1.32 at 20kHz
Room Size: 19x18

 

[PENG]

Eric, I don't have a scope, but using a Hioki meter my findings were similar to yours. I probably did not crank the volume as high as you did, I had the 3805 volume at 0, tried with and without the external amp, the currents put out by the 3805 was about the same as the 200 WPC (or 325 into 4 ohms) amp. Vp-p was quite low.

 

[Dan Banquer]

New amp

Eric Apple says:

"85 db is pretty satisfying to me, but not what I call loud. The 103 db was really way too loud and about the limit of the amp in the test setup."

This sounds pretty typical to me. Most folks typically prefer about an 80 db/spl average at the listening position.

Peng says:
"I had the 3805 volume at 0, tried with and without the external amp, the currents put out by the 3805 was about the same as the 200 WPC (or 325 into 4 ohms) amp. Vp-p was quite low."

The real clue here is that the Vpeak to peak is quite low. as your measurements show.

I also think it's important for folks who are giving measurements to give the speaker spl and the room size. Both will play an important role in how much power you are using.

Thanks to both of you for doing the measurements.
d.b.

 

[PENG]

Dan, fyi, in my case, room size: 12'X18'X8'. SPL from listening position (13') would be about 87 to 90 dB. For those who believe they hear that day and night, or huge difference, no data can prove them wrong. They will tell you they know what they hear. For those who don't believe, listening test won't do it unless it's a DBT of some sort. It does not really matter that much what we post, but I post my findings anyway, just in case it may help some of those who are sitting on the fence.

At my typical listening SPL level, I, along with friends in the house, could not hear enough difference between with and without the amp. My next move is to get a late model separate prepro and go from there.

 

[Eric Apple]

PENG said "SPL from listening position (13') would be about 87 to 90 dB."

At that SPL with the other info you posted the amp is probably loafing along at 2-3 watts, with 15 watt peaks when listening to the Black Eyed Peas anyhow.

The surprising thing to me about actually measuring this is the amount of power that it takes to go louder, and the required power headroom to support that.

Dynamic music range is where the power is really needed and the louder it's already playing, the way much more power you need. The same peak that took 12 watts when the avg was 2.25 watts, took 352 watts when the avg was 64 watts. In both cases it took 5 times the original power for that peak. So 5 times the power should be about something like a 7db peak.

If I were listenting to music with 18db dynamic headroom, I couldn't listen at more then about 80 db for the quiet passages because the amp would run out of gas on the peaks. A 18 db peak requires something like 64 times the power (calulated as 2xPower=3db). So if I calculate the peak power I observed divided by the mathimatical power required for 18db that would give the avg. power I could listen to that music. That's 352watts/64 = 5.5 watts or slightly less then the 85 db range I prefer. It's proabably in the range of 82 db avg though.

If I wanted just 3 more DB on the quiet end, the power requirement jumps up another 352 watts on the loud end. That to me really does say a big amp (or more sensitive speakers) has it's advantages when playing highly dynamic sources and you wish to enjoy music composed of mostly quiet passages at a nice level. But we are only talking a 3 db difference on the quiet end between a well made 100 watt amp and a well made 200 watt amp. This is because the peaks are over 100db because power requirements go up so quickly on the high end. The bottom line is that bigger amps may sound better when the average SPL is moderate because of the peaks needed to support the dynamic range of the source.

Of course, this all ignores the fact that a lot of recievers rated at 125 WPC into 8 ohms have rather aniemic power supplies that fold quickly and can't peak at over 350 watts into 4 ohms (even for a few ms) like the outlaw I measured. In that case, bigger looks even better.

Or, my math could be completely wrong...