EMOTIVA Thread Q&A [TECHNICAL TALK ONLY] - Page 482

No, as long as you're cautious of the master volume control on the preamplifier.

With regards to using 500 watt amps with speakers rated for at least half that power -

For movies, your speakers will likely have no issues, because movies have very short peaks of high power. And I have read that heat is a more common source of failure than mechanical failure ( the heat being generated by current through the voice coils.) So there's plenty of time, I think, for VCs to cool down with movies.

For music, I hope you are not pushing your speakers loud enough to damage them. That would imply SPL loud enough for hearing damage.

Some sources suggest have as much as twice the amp power as the speaker's continuous power rating.

Respected sources claim that speaker damage usually occurs when the amp is clipping, leading to high average levels which cause the voice coils to fail due to overheating (there are some good tehcnical articles online explaining the details.)

I would not consider using a 500 watt amp on speakers rated for 50 watts prudent though. Never tried it.

Just for the benefit of the OP, MJH, and for the avoidance of doubt, it is when an amp is underpowered that it will most likely clip and damage the speakers.

Personally, I think an amp of any (high) power output is good with any speakers, so long as one uses the master volume control with common sense.

Measurements are fine as far as they go. Almost all objective measurements are made with steady state signals. The media that we play through our systems produce extremely complex wave forms. As a consequence, some components that measure well with steady state signals may not produce results that are as close to what the produced of the media intended as a component that did not measure as well with a steady state signal.

Trust your ears. You are the one that must live with your system.

I purchased my first "high end" speaker system over 35 years ago after auditioning speakers and amplifiers for almost a year. ( My dealer was very patient and understanding. He is an independent dealer and is still in business.) I still have the speakers. The only things that have changed is a new set of drivers and a new amplifier 15 years ago. When I visit a friend who has spent around $100,000 over the last 18 months upgrading his system, the only thing that makes me want to make any changes to my system is his 65" flat panel.

Yes, his system does sound better than mine, but not $95,000 better to my ears.

I agree wrt to speakers. Other than the most important component in any system - way, way more important than amplifiers - the room, speakers are really where you can discern a difference between one and another.

I assume your friend who has spent $100,000 has a highly treated room - if not he's wasted a heck of a lot of money

Yep! However, I kept it in the Emotiva thread as opposed to going to the Onkyo threads telling them to buy a UMC.
Onkyo knows better than to give a five year warranty. That could result in them having to sell their remaining interest in the company. If Onkyo has not problems I will concede that it is perfect. Just direct me to the non defective Onkyo thread.

This discussion comes up every few weeks and each time it is as pointless as the last. I don't know why you felt the need to restart it again. All units have problems and faults, no matter who makes them.

What I said which provoked you to bring up the discussion for the millionth time was this:

"The issue here really is one of which is the best buy for about $1,500 - the untested Emotiva XMC, from a company which has a very poor rep for pre-pros to date, or a proven unit from a major player such as Denon or Onkyo? In addition, if one chooses the Denon 4311, one gets a proven room EQ system, Audyssey's consumer flagship version, XT32 plus the ability to use the Audyssey Pro kit if one wants the ultimate Audyssey experience."

That is a factual statement. There is nothing in there that is even slightly contentious. It is, IMO, good advice to the OP who wants to spend $1,500 on a pre-pro. I am not telling him what he should do - just what he should consider before he makes a decision as to what to buy.

It would have been better advice if you said "Onkyo has had their share of problems". If you do not want the discussion restarted then tell the whole story.

Well at least I gave some useful advice. As opposed to regurgitating something that was as useless the last time as it was mentioned as it was this time.

If I gave a list of all the makes that had had problems it would be all of them. If you think that would be helpful, google a trade directory of AVR manufacturers. If you think it's only Onkyo that have had issues with various units, then you are deluding yourself I regret to say.

How about Denon? I suggested Denon as an alternative to the XMC too. You didn't mention Denon - any special reason for that?

I assumed it was implied that you only clip when you run out of power Given enough power, clipping won't occur, as you point out.

As for why clipping causes damage, that's an interesting topic, in which even experts seem to offer slightly different explanations. It's clear it's not due to distortion...the speaker could care less about distortion, except if the distortion is a cause due to the effect of exceeding it's excursion limits (in which case, it's not distortion hurting the amp, distortion is the symptom.)

One thing the explanations seem to agree with...the cause is usually failure of the VCs due to excessive heat.

In case people are interested, here's a few links. They differ a bit in explanation. The second link focuses more on woofers ( not surprising, as it's a car audio site.

I post this because I see a lot of confusion from people thinking too little power blows speakers. If that was literally true, speakers would blow when no signal was going through them. Saying that too much power blows speakers is more accurate, IMO - as long as you understand the parameters. 1000 watt amps are not going to blow 1 watt speakers if the max power they are putting out is 1/4 watt. 200 watt amps should not damage 100 watt speakers under normal use, because their average power output is not 100 watts under normal use. But you need all that power for peaks, which could be 100 times average (based on THX's reference level of 20 dB dynamic peaks.)

http://sound.westhost.com/tweeters.htm
http://www.bcae1.com/2ltlpwr.htm

Why do you constantly regurgitate useless info? Your advice was partially useful. If only you had not stated that Onkyo has an excellent track record. I doubt any brand has more negative posts. As I have said numerous times, I like Onkyo. I also like the UMC. I have not denied the reported problems with the UMC and if I recommended it I would make it know that issues exist.
Denon has far fewer issues than Onkyo AFIK. So does Yamaha.
There is also the customer service issue. Onkyo has the worst and Emotiva one of the best.

What are the relative sales numbers for these brands? It would be entirely too premature to knock one over another if the relative numbers are significantly different. In other words, if Onkyo sales are three times the number of Denon or Yamaha, you would expect higher # of issues.

I wasn't recommending any brand. I was giving information useful in helping the OP make a decision.


And you know that how?

Look, don't bother replying. I am done with this pointless discussion now. If you reply I will do you the courtesy of reading your reply, but I won't respond to it. I am sure the OP is able to decide which posts are useful to him and which aren't.

I have never had a problem with Onkyo's customer service. Repairing an out of warranty product is pretty good customer service IMHO. And there is no substitute to listening for your self. There are too many variables that go into an audio system without considering the unique individual listening to it. Everyone has there own bias and unique "wiring" and "components" within their body. I tried the Denon but preferred the Onkyo. Everyone has there own preferences. Choice is great, no choices would be boring!

Chu Gai has posted often about this subject and within this thread, as far as I can recall. Just do an advanced search within this thread for posts (not threads) with key words like, "UL" or "certification" under his specific user name.

They have to have the CE mark - it's illegal to sell a unit here in the EU without it.

You are partly correct. Here is all you'll ever likely want to know about it: http://en.wikipedia.org/wiki/CE_mark

I thought the article was pretty clear.

But the issue for Emotiva is that without the CE mark they couldn't legally sell their units in the EU.

You are not allowed to bring a product to market within the EU without a valid CE certificate. There is no independent testing been done, but the manufacturer or importer has to declare (and make sure), that its product follows certain rules and standards. If found not to adhere afterwards he will get into all sorts of legal trouble.

CE allows a company to self certify that their product meets the appropriate standards applicable for that product. The standards for a toaster are obviously different from a DAC or a CD player. Further, a product may need to meet several standards in order to be legally sold. While I don't know if the following is a CE standard, there is a move in Europe to mandate tougher standby power consumption requirements which you can Google up for further information. So, if you see some personally cherished amps being phased out, it may be because their standby power consumption is simply too high.

While some companies just slap a CE logo on the product, others do go to the trouble of not only testing the product but indicating in their manuals just what CE standard they claim compliance with. Check the manuals of something like a Pioneer receiver and you'll see it written along with a sign off signature indicating responsibility. As to what Emotiva does, you'd have to ask them and they should have no problem answering questions in a public forum without derisive remarks. After all, a company that's in compliance has made an internal effort and commitment to play by the rules and one would think would be proud to make that publicly known.

The CE standard largely only has meaning overseas. In the US, other standards exist and there are differences from the CE ones. For example FCC Part 15 B. One will notice that Emotiva's current CDP has the FCC logo on the back while IIRC, the prior one didn't. However, the FCC is quite specific as to the language to be used in the manual and the manual for their current CDP does not conform. Whether that's because the people who write their manuals are clueless or because the company is fudging things, I don't know.

Also as a point of fact, products sold here that come from other countries must have a 'Country of Origin' sticker, label, printing, etc. If for example one buys interconnects that came from China, there ought to be some kind of indication of the country that made them. A company selling things like Chinese interconnects is not allowed by Federal law to remove them.

Just for general info and completeness, that 'country of origin' regulation also applies in the EU.

Check out a 'German' speaker called Teufel. They seem to have found a way around it.

So when's the expected release date of the Xmc-1? I just noticed on their site last night along with a 100x5 amp. I'm curious if emotiva got it right this time around.

They can, of course, ignore the regulations... I am not sure about the ins and outs of the 'country of origin' regs - it may give an escape route somehow if, for example, the final assembly is done within the EU but using parts sourced 100% from outside the EU. 'Final assembly' of course for a speaker might be simply screwing the drivers in...

You would think that if the amp is properly grounded, and there's overload protection in transformer (would be a one shot fuse,) and it has thermal, voltage and current protection circuits for the power stage, it's pretty safe. I don't know that for a fact, just guessing.

You would also think, a company selling amps that can handle handle 5 amp peaks on multiple channels has taken steps to ensure the products they sell don't subject them to expensive liability lawsuits. I could be wrong of course.

My first XPA-3 "blew up," but did not catch on fire, so that was a good sign...I think

I'm curious if Lindsey Lohan is finally sober and driving without hitting people. I'm also curious if N. Korea is going to finally stop their nuclear program.