Axiom Home Page Forums General Discussion Home Theater Emotiva Setup

I intend to build up the Epic-80.180.500. Wondering which should be a better combination of Emotiva amps (with a flexibility to upgrade to 7.1 ch):

1. XPA 2 + UPA 5 OR
2. XPA 3 + UPA 5

Considering that I'll start with m80's, would the headroom provided by XPA 3 be enough to get the best sound out of M80's (and VP180) or should XPA 2 be my choice. My setup will be used for 70% music and 30 movies.

Thanks

I power my m80's 150 and qs8's with a xpa5 and it sounds great.
Either way would work but if music is 70% of your listening in stereo I would get the xpa2. (its probably overkill though) If the setup was more for theater I would get the xpa3
If you have the money and the circuitry capacity I'd wait for the XPR7

I would consider Outlaw Audio amps as well, as they have a much better track record with the M80's. How big is your room and how loud do you listen?

The difference in power from the XPA 2 to the 3 I would estimate about 3db give or take depending on room, listening distance etc. I would go with the XPA 3 just have the center with the same power as the mains.

Sarang, "headroom" doesn't help to get the best sound out of the M80s or any other speaker. You should calculate the maximum volume level that you'll be hitting on brief peaks and should have a maximum amplifier output capability that can handle it. No additional headroom beyond this is either necessary or helpful.

I like to think of that 'headroom' as future proofing for a bigger room where I could then make use of it

I like to think of headroom as safety margin as long as it does not come at a large cost penalty.

You don't red-line your car all the time either.

I feel that if you don't have head room, you have limitations that will impact the sound in some audible fashion.

Why? If you're not hitting your head, it doesn't matter if you've got 1 foot or 10 feet of headroom.

One thing I think though, is that momentary clipping is more common than people realize, and that the recovery from a clip varies from amp design to design.

In that case though it's not headroom, but used power.

But your probably ARE hitting your head.

Then it's not headroom.

Thanks guys for the response.

I need a multi-voltage amp. since i may be moving out of the country by next year. this narrows down my options quite a bit. Outlaw, unfortunately, only provides with 110v option.

Although, I will be using the M80's at normal listening levels at most times, I may pump up the volume for small parties. Not sure what should be the ideal volume for a party, but a good headroom will definitely take away any concerns.

i have prepared a small excel worksheet showing various dB levels at varying distances from the speakers.

Speaker Sensitivity 91 dB
Gain in Stereo Setup +3 dB

Distance from Speaker (in meters)
Wattage 1 2 3 4 5 6 7
1 91 85 82 79 77.5 76 74.5
2 94 88 85 82 80.5 79 77.5
4 97 91 88 85 83.5 82 80.5
8 100 94 91 88 86.5 85 83.5
16 103 97 94 91 89.5 88 86.5
32 106 100 97 94 92.5 91 89.5
64 109 103 100 97 95.5 94 92.5
128 112 106 103 100 98.5 97 95.5
256 115 109 106 103 101.5 100 98.5
512 118 112 109 106 104.5 103 101.5
1024 121 115 112 109 107.5 106 104.5
(Sorry, coudn't find a better way to paste from xls). Read: 91dB @1W, 1M distance and so forth.

Now, if I use XPA 3 (300W @4ohms), i would get around 106+3 dB @3m distance from the speakers. While with XPA 2 (500W @4ohms) I'll get 112+3 dB at the same distance.

Now the problem is that I don't know how loud 109dB or 115dB is? Has anybody out here gone upto 115 dB? Or is 109 dB more than enough for a small party?

Thanks

Really, really loud.

10 dB Normal breathing
20 dB Rustling leaves, mosquito
30 dB Whisper
40 dB Stream, refrigerator humming
50-60 dB Quiet office
50-65 dB Normal conversation
60-65 dB Laughter
70 dB Vacuum cleaner, hair dryer
75 dB Dishwasher
78 dB Washing machine
80 dB Garbage disposal, city traffic noise

Prolonged exposure to any noise above 90 dB can
cause gradual hearing loss
84 dB Diesel truck
70-90 dB Recreational vehicle
88 dB Subway, motorcycle
85-90 dB Lawnmower
100 dB Train, garbage truck
97 dB Newspaper press
98 dB Farm tractor

Regular exposure of more than 1 minute
risks permanent hearing loss.
103 dB Jet flyover at 100 feet
105 dB Snowmobile
110 dB Jackhammer, power saw, symphony orchestra
120 dB Thunderclap, discotheque/boom box
110-125 dB Stereo
110-140 dB Rock concerts
130 dB Jet takeoff, shotgun firing
145 dB Boom cars



I hate jackhammers..

I would believe all the SPL are measured @1M from the source??

So to make my room as loud as a discotheque for a party, i'll need to reach 120 dB.

Also, when measuring the speaker sensitivity, does is consider dB @1kHz or the entire range??

I think you should be making it even better than the club and aim for 150dB.

A birdy just whispered in my ears that dB that high can be potentially hazardous for me !!

i would be extremely surprised if you could stand 120dBSPL for more than a very short time at a party.
around 105 dB is the max for movies; LFE up to 115 dB; it's designed for that.

After experiencing temporary hearing loss for several weeks and having extreme sensitivity to sound at times being muffled with ear fullness, intermittent ringing, buzzing and "whooshing" in the ear, I wouldn't wish it on my worst enemy. It hurts more than your ears but overall how you feel and general quality of life (disrupts sleep, headaches). Be careful with that volume dial folks!

Thanks for sharing your experience Dr.House.

So that makes me zero down on XPA 3. This provides me with sufficient SPL (around 110dB in stereo) and also a headroom of around 4dB over and above 110db (considering room gain). This headroom will make sure that the amp does not go in clipping even at such high volume.

Thanks for the help guys.

Sarang, those numbers are invalid. They're based on the 6dB per doubling of distance factor which applies only to an omnidirectional sound source in anechoic conditions. For home listening rooms both direct and reflected sound has to be taken into account. Research by Dr. Toole and others has shown that the typical factor for such rooms is 3dB per doubling of distance, rather than 6dB. At 2 meters only half of the power calculated using the 6dB factor would be required and at 4 meters only 1/4th the power.

If you don't mind damaging the hearing of your guests and yourself those 100dB plus numbers which you've suggested would be appropriate. A safe average level shouldn't exceed about 85dB, with only brief split-second peaks hitting the 100dB area.

in Montreal, a rock band leader was practicing on the stage prior to a concert.
after a short while he calls the resident tech. and tells him that the monitors he installed are no good, he "barely can hear" himself playing.
the tech takes SPL readings and shows the musician the results: 120dB SPL.
the musician gets mad and yells at him that the equipment is no good, that he better change it for something more powerful...etc.

John, as per Dr.Toole's calculations, I will be getting a higher dB @3mts from the speakers than the number calculated by me. This goes on to show that XPA 3 would have enough headroom and be able to play speakers at deafening sound levels. XPA 2 clearly has more unusable power and headroom and therefore, a waste considering the high sensitivity of m80's.

Thank you all for helping me decide.

Wow! So the XPA2 can play even louder than deafening levels! Totally agree, what a waste!