Axiom Home Page Forums General Discussion Advice from Axiom Owners A/V receiver for Epic 80?

Can anyone tell me what kind of A/V receiver I would need that would bring out the full potential of the speakers and be safe to use with Epic 80?
I’m confused regarding Ohms and power per channel.

1. How my future receiver should be rated in Ohms considering that in Epic 80 M80ti - 4 Ohms, QS8 & VP150 - 6 Ohms and EP350 - 8 Ohms.

2. And what receiver’s power per channel should be to get as much as possible out of these speakers without blowing them up.

Could you please advise on which A/V receiver(s) would be compatible with Epic 80. Preferably, not very expensive ones.

Thanks.

call joe at axiom, he'll advise you.
dan

any receiver that handles a 4ohm load is good.

I hear HK doesn't do this well, however, Denon and Yamaha do.

how much do you want to spend?

by the way, the impedence of you sub makes no difference, it amplifies itself

I wouldn't want to go above $500-700 for a receiver alone.

1. So what if a given receiver rated at 8 Ohms - it will still perform fine with M80ti(4), QS8(6 Ohms) and VP150(6 Ohms)?

2. And what about max. power per channel? Most of the receivers I've seen rank at 200W/channel. M80ti - 400W each. Does that mean I would not get a full power potential of the speakers?

I appreciate your reply...

Check out the Yamaha RX-V1300 and 2300 models and see what you think.

Marik, read all the links chess supplied, but within the dollar range you mentioned I'd suggest that the HK525 can fit in there, but if you can go a bit higher(it can be found around $800)the Pioneer 45TX deserves strong consideration.

Don't worry about the maximum power ratings on speakers; that's about how much that they can take without going up in a puff of smoke, not how much they need. Most of the time speakers use about 1 watt. On brief moments at high peak sound levels they might require 100 watts or more. These receivers can do that and won't limit the potential of the M80s.

The NAD T752 might interest you. It has plenty of power (a bench test I read measured it at 92w/channel - all channels driven) and can readily drive a 4 ohm load. It is a 5 channel receiver but it does have a 7.1 front end if you ever want to upgrade in the future. Lastly, NAD is known for being a musical receiver.

You can find it for around $700 online and should be able to negotiate a price around the $800 mark from an authorized dealer in your neck of the woods.

The HK 525 is also a fine choice. You really couldn't go wrong with either.

John,
But if receiver rated 100W/channel and played at high volumes, how much in watts your speakers outputting?
See, that was my question - M80ti are capable of 400W...

Mike,

I checked NAD T752 and NAD T761. NAD T761 rated 80W X 5 Continuous Power into 8 ohms.
You've said that it drives 4 Ohms with no problem - why it doesn't say in receiver's description...how can I be sure?

Thanks.

Hi Marik,

Check with NAD's site or a technical person there. Also, current Harman/Kardon models, including the AVR525, which I use, drive the M80s with no problems.

Manufacturers are sometimes evasive about 4-ohm capability, because their receivers may have "current-limiting" circuits that limit output power driving 4-ohm loads (or in some cases, shut down the receiver temporarily). H/Ks are ok, so are Denon and, from everything I've read, the NADs.

If a receiver has a back-panel switch for a 4-ohm load, don't get it. The switch will limit power output to the M80s so the output transistors don't run hot.

Regards,

Wattage at the speaker end is just a measurement of how much power the speakers can take without blowing. It is not a measure of how loud the speakers can go, etc. In fact, it is an overly quoted, unimportant factoid, if you're looking at decent speakers. Basically, if the speakers can't take 100 watts, I wouldn't touch them, but other than that, the wattage rating is unimportant.

kcarlile,

Thanks for your input on this.
I know that wattage for speakers is how much it can handle without blowing up.
But what I was asking: If, for example, a certain receiver is 100W/channel and it's used with M80ti speakers (that actually can handle 400W/channel), does that mean that that's all they're getting, 100W each, at high volume or whatever. Or am I missing something?

Essentially, yes. 100 is an average power at full volume (I think), so it will peak much higher than 100 Watts. Unless you're dealing with very low wattage amps (like, 10W, say), the speakers will be performing optimally.

kcarlile,

From what you've said I'm sensing that a receiver rated 100W/channel actually capable of providing more watts to speakers at higher volumes?
Confusing...and if it's not true, then what's the point of 400W speakers if all that they can output is what 100W receiver gave them? Then maybe makes more sense to get 200W speakers?

See what I mean?

Thanks.

Get the speaker which sounds best to your ears. FORGET about what the handling capacity is. It's NOT important.

OK. Amplifiers are rated generally in root mean squared, which is a way of averaging power. In essence, they take the average of the output power, take the square root, and then square it. (If someone actually has an EE background, feel free to correct me). Therefore, an amp may put out 50 watts at one point, and 150 at another, which would average out to 100. Amps do not continually put out one wattage. There are peaks, which are the reason to get speakers that can handle higher wattage than the amp puts out.

kcarlile,

ok, I see. But is it possible for a 100W receiver to peak at anywhere close to 400W?

Thanks. I'm learning a lot here.

spiffnme,

But it is important to me...that's the reason I'm interested in Epic 80 system.

marik,

There are three factors with regard to how loud a speaker plays:

(1) Efficiency -- Usually measured as dB/W (in-room or anechoic), it dictates how much sound pressure the speaker produces at the distance of 1 meter in front of it when driven with 1W of power.

(2) Maximum sound level -- The absolute maximum sound pressure playable by the speaker within a given limit on distortions (for example, 110dB at 1kHz at 2% total distortions).

(3) Maximum power handling -- The maximum amount of power input the speaker can handle without breaking itself (regardless of how loud it plays at that level of power).

An important thing to remember here is that, in the vast majority of cases, (3) is irrelevant because (2) is reached way before (3). For example, the M80 is a very efficient speaker with 95dB/W of rated in-room efficiency. If you do the math under the assumption that there is no limitation (2) above, then with 100W of input, the M80 will play at 115dB; and with 400W, 121dB. But in reality, I do not think the M80 (or any ordinary non-horn-loaded speakers) will go much beyond 115dB or so, perhaps much less if you are talking about a “clean” reproduction (there is no published specs of max sound level available). This is why (3) above is irrelevant, other than it gives you some peace of mind.


kcarlile, let me pick nits.

This is a very common misconception, but in fact, there is no such a thing as “RMS (root-mean-square) power.” RMS is a measure of AC voltage or current: To calculate RMS, you square the instantaneous voltage (or current) first, time-average it over one cycle or more, then take the square root of the average. Since the power (W) has the dimension of [voltage (V) x amperage (A)] with always-positive values, you do not do the above. In order to get “average power,” you simply time-average the power.

OK...my brain is in a knot now, thanks sushi.

Ah. I am enlightened. Thanks! :-) I knew there was a reason I stopped being a Physics major...

Marik,
First, I demoed this receiver at a local hi-fi shop and it was hooked up to five 4 ohm speakers at the time. Secondly, I read a bench test on this receiver....I will try to locate the article and supply the URL when I have time.

The following is a copy and paste from NADs website:

"Power Output Stereo Mode 2 x 90W (19.5dBW)
Simultaneous Continuous Output Power into 4/8 Ohms * 5 x 80W (19dBW)

(*Min. power per channel, 20Hz - 20kHz with no more than 0.08% THD rated distortion.)

IHF Dynamic Power 8 Ohms 2 x 150W (21.7dBW)
IHF Dynamic Power 4 Ohms 2 x 200W (23dBW)
IHF Dynamic Power 2 Ohms 2 x 225W (23.5dBW"

The review on the NAD T752 is in the December 2002 issue of Sound & Vision. I read the full review including the "In The Lab" section. I can't find the full review online from Sound & Visoin but NAD has part of the review (no 'In the Lab' section) on their site.

Go to the review section on NADs homepage and click the Sound & Vision link.

Marik,

Here is a little something that might help you with some of your questions. Its a nice little article that applies to all receivers (not just NAD) in termsp of rated power etc. It also contains commentation on how NAD can drive 8, 4, and even 2 ohm loads.

http://www.nadelectronics.com/power/index.htm

The NAD 752 is great. Loads of power. There only one quirk .It has a fan which spins rather loud at time when the amp get a littel too hot. Not too often though. My dad loves his 752.