Axiom Home Page Forums General Discussion Home Theater Most Musical HT Receiver

Hi Folks,

I do not wish to solicit a flame war, but have to say that music materials do readily go down to the 20Hz realm. And they do without any syth or electronic sources. The base tone for the lowest key of a piano is 27.5Hz (4 octaves down from the 440Hz "A"). A large organ will go at least 1/2 to full 1 octave further down. And this is so far considering "tonal" instruments only. Enter the purcussion; a large bass drum or gong will readily produce sound components down to well below human audible limits.

Cheers!

Oops, forgot to include my own question... LOL

It seems that opinions on the Pioneer Elite receivers are divided. Some seem to value the MCCAC feature, while others say it is mediocre even as a "starting point" setter. Some warn on the lack of power reserve and inability to properly drive 4-ohm loads, while others say that this has been fixed in firmware in recent shipments. Some are worried about Pioneers running so hot, while others say other brands can also get quite hot (I do know that Pioneer recommends a very generous clearance, like 1', above the receiver for heat dissipation).

Pioneer's VSX-45TX is one of the candidates I am considering to purchase for my new 5.1 system. But somebody suggested to me that a Denon or H/K might be a better choice, especially given that my Hales is rated 4 ohm.

So... what is the update on Pioneer's reputation, and what are the best-buys under $1,000 street in your opinion?

First,sushi, on MCACC(Multi Channel ACoustic Calibration),although I haven't tried it, my impression is that the great majority of reports from owners is highly favorable. It would seem that if even a partial correction of response irregularities caused by the listening room and/or speakers can be achieved with so little bother, that it's a worthwhile addition to a receiver. It should be noted that Pioneer announced at last month's CES that 3 of their new line of lower cost receivers(out in March)would have MCACC, including a microphone for automatic operation on the 912( 6 X 110 watts; probably $300-$350 street price).

On the 4ohm question, I suppose that we've read the same reports and they're so conflicting that I don't know what to make of them. The technical reason given for the rumored "fix" a couple weeks ago made no sense to me. I'd be inclined to give it a try. In roughly the same price range the Denon 3803 and Sony DA4ES would also be fine choices(wonder about the loud fan reports on the HK525).

I was looking at Pioneers last year before i bought my Onkyo.
Sound quality aside, the specs for the Pioneer top model (MSRP $4000Cdn) were rated for 6 ohms and up.
I was downright shocked that their flagship model was not listed as supporting 4 ohm speakers for that much cash.

In having a former roomate that owned a Pioneer, and having gone into a shop to look at a VSX 39TX, i can attest to the generous heat output of their receivers.
These two qualities alone made me question the build quality of Pioneer receivers.

Then the final straw. i received a bad review from one of the local electronics gurus here (not a salesman) who also had a rather negative comment on the Pioneer receiver build quality, basically something to do with inadequate amps and heatsinks. I won't go looking for Pioneer receivers again until i start hearing (and reading) better things.

All that aside, i think Pioneer receivers sound just fine and i have seen them drive 4 ohm speakers before, but hey, my Onkyo does the same thing, for the same price, but virtually without any heat.
I believe Denons fall into the same, low heat category, although there have been a couple of posts about H/K also running rather warm.
If you are looking for under 1k, i do suggest you take a look at the Denon, Yamaha and Onkyo offerings.

Well... I did a bit of research on the power consumption specs of several receivers in the price range of under $1,000 street.

Obviously, a receiver can never send the speakers a higher (continuous) total wattage than the wattage it gets from the AC line. So, I figured that the rated AC power consumption of a receiver would likely give us some insights into its "power reserve" and aspects of design philosophy. Of course, this is under the assumption that the manufacturers are fairly honest about the AC power specs (which I guess they must be because of safety regulations). So, here are some results:

Denon AVR-3803: 566W** / 7.0A

H/K AVR-7200: 1040W / 12.9A**

Onkyo TX-SR800: 655W / 8.1A

Pioneer VSX-45TX: 600W / 7.4A**

** Presumptive calculated values based on Onkyo's specs, which list both wattage and amperage (since the power transformer in an amp is not a purely resistive load, you cannot get wattage by simply multiplying amperage by voltage). All amperages are at 120V AC.


Assuming that these listed and calculated values are not grossly different from the real maximum power consumption of these receivers, it is quite interesting to look at these numbers. For example, the Denon appears to have the lowest maximum power consumption, despite the fact that it is rated at 110W x 7 (all others are rated 100W x 7) and despite its reputation of good power reserve. If these numbers are correct, the Denon cannot possibly feed more than ~560W of total continuous power to the speakers.

H/K's numbers are striking. I also found that this receiver is listed to consume as much as 120W when idle (powered on, but no signal). My guess is that H/K's final stage uses a relatively "shallow" design of Class AB operation (i.e., closer to Class A design, with lots of shunt currents), which might provide some benefits on sound quality and dynamic power handling. Anyway, no wonder the H/K has a reputation of running quite warm even when idle. By the way, will the 7200 have a cooling fan?

How about the Pioneer? Considering these numbers in conjunction with Pioneer's reputation of also running quite warm (again, probably reflecting a shallow Class AB final-stage design), I would have to agree with some folk's claims of its relatively anemic power reserve.

Just my 2 cents...

One very important thing to consider when it comes to electronics......HEAT. It is a very simple formula. Less heat=longer life. You don't have to be Bob Carver to understand this principle. I simply would not purchase any receiver (no matter how great it sounded etc.) that runs noticeably hot.

Hi Mike,

Yes, I agree with your "less heat=longer life" thought, but only with everything else being equal. And I want to believe that the engineers at whatever brand that runs hot know that much.

When it comes to the issue of an amp's heat handling, I think we have to consider two different things:

(1) How much heat is, by design, generated by the power-stage transistors (and other components), at various power output levels.

(2) How well the generated heat is dissipated.

I do not have any hard data here, so the following is all my speculation (something I really don't like ). But I just cannot believe that the differences in the operating case-surface temperature is all ascribed to (2), i.e., a severely inferior heat-dissipation design in the hot-running brands. The consensus seems that, for example, Onkyo and Denon generally run cool, whereas Pioneer can get very hot. But does this automatically mean that the engineers at the latter brand care less about heat and try to skimp on thermal management? Umm... not very convincing to me.

Just as a side, among those 4 models I listed above, H/K and Pioneer, the two allegedly hot-running models, are in fact heavier than the other two. Where do these brands invest that additional amount of metals? I do not know...

Well, I start to realize that these comparisons only confuse me. And, to be honest, I seriously doubt that I can hear a clear difference in sound quality among these models (unless I have a chance to do a true A/B testing at my home, which I do not think I can). I already know from my casual auditioning at local stores that all these brands at this price range sound, well..., wonderful.

So, after all, I guess I will have to decide based on factors that are obvious, including functional features, appearance, and the ability to drive various loads properly, etc... Operating temperature will unlikely be my primary criteria. I do not think they are that stupid...

Sorry for this confused, vague post...
Cheers!

You have more confidence in the engineering quality of a 'for profit' company than i do Sushi.
Although i'm sure they have minimum requirements for their heat dissipation components, etc., i would prefer to buy a unit that goes beyond minimums and into the 'very safe' zones.

If an amp is running hot, but weighs 10 pounds more than one that does not, what does that say?
Perhaps different metals were used? Maybe same metal, same heatsink weight, but more plastic in the lighter unit overall.
Perhaps electronic components with less tolerance in the hotter unit?

There are alot of possibilities really, but in the end, i prefer not to mix extreme heat with electronics if i can avoid it (too many burned cpus from overclocking....not that i can overclock my receiver, but if i could....).

I would just err on the side of caution as opposed to trusting that the company knows what it is doing and perhaps what they are doing is cutting corners to cut costs albeit within safety specs.

Of course there is also the thought that a hotter unit warms up the already high temperatures in your listening room down there in balmy Texas (it was -49 here yesterday with windchill). If anything, maybe you should be trying to look for a receiver unit that actually cools your room when its turned on!

In reply to:

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JohnK: on MCACC(Multi Channel ACoustic Calibration),although I haven't tried it, my impression is that the great majority of reports from owners is highly favorable.

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I have to agree. I went through many AV/HT forums pretty exhaustively on this subject, and most Pioneer Elite owners seemed to be making a valuable use of MCACC.

In reply to:

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JohnK: On the 4ohm question, I suppose that we've read the same reports and they're so conflicting that I don't know what to make of them.

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It seems that at least one person who had had the 4-ohm shutdown problem got it actually fixed by Pioneer. See this and earlier posts by the same person.



Also, thanks for the info on the new VSX-D912-K. Looks like this model has, besides the auto-MCACC, just enough set of features for many potential buyers. For example, they did not omit rather important things like 7.1 analog inputs. This model might be a great bargain indeed, if you do not need the Elite warranty/appearance/pride.

For others who are interested, here is the press release.


Cheers!

Here is an update in case anybody is still interested...

The auto-MCACC on the new VSX-D912 receiver does not include the equalization feature that the Elite models have. For me, this makes it basically useless; one can do the basic balance/delay calibration just fine with a RadioShack SPL meter and a measuring tape. The per-channel equalization is the feature that makes the MCACC unique and potentially valuable. After all, you get what you pay for...

Also, I just got their response to an inquiry about the 4-ohm shutdown issue that I sent directly to Pioneer's Tokyo headquarters. They flatly deny that the "issue" exists, saying that the specs clearly state that speakers rated 6-16 ohm should be used with the Elite receivers, and these models are designed accordingly. They also deny that they have done or will do any update, repair or modifications to the receiver to accommodate 4-ohm loads upon a customer's request. They said this even though I phrased my inquiry sound like the 4-ohm issue is the make-or-break factor for my purchase decisions in the very near future. Incidentally, they were prompt and appropriately polite in answering my questions.

So, I guess I have to conclude that Pioneer, for whatever reasons, does not want to go public or official on this issue; they even took the risk of losing one potential buyer in denying the issue. On the other hand, judging from recent posts in various forums, Pioneer does seem to "fix" it on case-by-case basis upon customer requests, apparently regarding the fix as the normal repair of an individual malfunctioning unit under warranty.

Just FYI...
Cheers!