Pro vs Consumer - Confusing Distinctions?

[GrimSurfer]

A few months ago, I participated in a discussion elsewhere on the use of "pro gear" in home theatre. Looking at the respective specs, I saw a reliable correlation between higher THD+N and IMD and pro gear. This was explained by the fact that the majority of pro amps employ Class D topologies. The high output powers involved also necessitated this use of fans which, I contended, raised the potential for audible artefacts in a home setting.

What I've mentioned above are generalities... there are certainly pro amps out there whose specs meet of exceed the levels of marginal consumer gear. The spl goals at public venues also make it more likely that pro gear will offer higher output power (though many manufacturers of such gear quote peak/PMPO, which can be misleading).

To their benefit, pro gear is almost always grounded for safety reasons in open environments. Many accept balanced connectors, which we know can reduce noise when correctly employed. But connecting pro and consumer gear (ie consumer preamp with pro amp) can create challenges of its own. None of these are insurmountable but they do add another layer of complexity/potential problems (ground loops, level and impedance matching, etc.) to the mix.

Other than, perhaps, powering passive subs, my view is that many pro amps aren't the ideal choice for home use. Sure they're inexpensive but the specs reflect an entirely different set of priorities (high emphasis on power density, low emphasis on THD+N and IMD, and very little acknowledgement of fan noise).

I think one of the things that confuses people is the term "pro". Some people equate this as meaning better. I think it's a very general term that is used to describe it's intended use/setting and doesn't necessarily imply anything qualitative at all.

Dollar for dollar, pro amps can appear attractive at first glance... but the cynic in me says "read the fine print... you might get what you pay for".

Thoughts?

Edit: changed double insulated to grounded.

 

[Sawdust123]

Good pro amps are priced in kilodollars, right up there with some high-end consumer amps.

If you look at the horsepower rating of a diesel truck, you will see they are no more powerful than a Corvette. That is, until you compare torque ratings. The difference between pro and consumer amps is similar. A consumer amp isn't going to drive speakers at 130 dB SPL (1m) for 10 hours straight but a pro amp can. At 130 dB, speaker distortion will be so high that amp distortion is of little concern.

i wouldn't worry about pro and consumer line level differences (1.23V vs 0.316V) since most pro amps have sufficient gain adjustment to make up the difference. I can't imagine any consumer preamp having difficulty interfacing with a pro amp. All the pro amps I have used would work with an unbalanced input, you just ground pin 3 of the XLR input. Ground loops are no more or less likely due to the classification of the gear.

 

[GrimSurfer]

Agree on the really good pro amps. The pro amps these guys were talking about were ~$500 ATIs and the like. The specs on some of these amps were pretty marginal...

You'd be surprised (or maybe not) the number of times these amps would reportedly shut down trying to drive a 4 ohm nominal load at moderately high spl! Or worse, clip and damage speakers. The thought that "pro" doesn't mean much outside of a narrowly defined environment or qualitative considerations seemed too emotional for many to accept.

Agree on distortion at 130 dB in an open (or any) forum is likely to be a big concern. The ambient noise at such venues is often quite high... at least 50 and quite often over 70 dB.

Distortion at 80 dB spl in a quiet home theatre setting is another thing altogether, especially considering what a John Siau was writing about in the thread on the AHB2.

The torque vs. horsepower is an apples and oranges thing, as you correctly point out. The power train in the vette won't last long hauling large boats up the ramp at the marina. The diesel truck, however, can do this without breaking a sweat. I guess that's my point about matching the gear to the use... which is why I have difficulty accepting the logic behind what ppl are saying on the HT net.

 

[sergeauckland]

Pro is a catchall term that doesn't have any real meaning. Pro, as in project studios? Pro as in Abbey Road? Pro as in pub band PA? Pro as in Stadium rock PA? HiFi as in Schitt, HiFi as in D'Agostino?

All that distinguishes all these is the intended application and suitability for use. I happen to use project studio amps in my home Hifi as they are adequate for the task I expect them to carry out. There's no pride of ownership involved, they just work, and have done for some 6 years. Others wouldn't let them through the door as they look cheap, and indeed are cheap, yet they work fine.

I wouldn't concern myself with the Pro or Hifi label, just buy what does the job.

S

 

[Sawdust123]

Is ATI considered pro gear now? I guess they are used a lot in movie theaters. When I think pro, I think of touring sound. Of course, I differentiate pro and commercial. I consider ATI more of a commercial amp. However, the owner of ATI also designed Adcom's famous 555. They also made amps for other well known hi-fi brands.

 

[SIY]

I thought the 555 was a Nelson Pass design?

 

[andreasmaaan]

I take it by "pro" you mean PA gear, right? Such amps tend to be more consistently middle of the road, with performance better correlated to price IMO. Consumer amps are more all over the place in terms of price to performance ratio.

The very best-performing stuff is sold as consumer gear, but plenty of pro (PA) gear is adequately good, ie does not introduce audible distortion (e.g. stuff from Powersoft, Crown, etc).

When it comes to bare components and in particular class D boards, there's also some crossover between PA and consumer gear, even if the names on the enclosures are not the same.

I guess what I'm getting at is that there's no magic sauce missing from pro gear. You might not quite get state-of-the-art noise and distortion figures, but only a handful of consumer amps will give you that anyway. Good pro gear is good enough for transparency and arguably tends to be a safer choice for some of the reasons you give in your OP (grounding, reliability, etc).

 

[restorer-john]

I thought the 555 was a Nelson Pass design?

https://www.audioxpress.com/article/Interview-with-Nelson-Pass

 

[GrimSurfer]

I take it by "pro" you mean PA gear, right?

I very much take your point... it's the same one I used in my discussion elsewhere. We were discussing a particular Crown amp (XLS if I recall correctly). The owner's manual said it was designed for PA use, which I pointed out.

The howls that followed!

The very best-performing stuff is sold as consumer gear, but plenty of pro (PA) gear is adequately good, ie does not introduce audible distortion (e.g. stuff from Powersoft, Crown, etc).

I'd let the measured and verified figures speak for themselves on this one, andreas. The specs on a lot of the gear being purchased by the HT crowd are quite loose. Surprising, given that HT is frequently operated at reference levels or higher.

I guess what I'm getting at is that there's no magic sauce missing from pro gear. You might not quite get state-of-the-art noise and distortion figures, but only a handful of consumer amps will give you that anyway. Good pro gear is good enough for transparency and arguably tends to be a safer choice for some of the reasons you give in your OP (grounding, reliability, etc).

I very much understand your point. It isn't missing sauce... or even price. It's the differences in intended use affecting design and, ultimately, certain measures of performance.

As far as consumer audio goes, I think things are so screwed up that it is becoming impossible to disentangle the mess before us. There doesn't appear to be any connection between cost and performance or value and performance. This gives rise to the internet lore that two 100W amps of different design, quality, etc will sound the same at moderate listening levels. This is something that John Siau addresses in a most convincing way in the AHB2 thread.

None of this is an indictment of pro amps or even Class D ones. The issue, in my mind, is understanding the differences between pro and consumer gear... and being able to make informed choices that are mindful of the features of each.

Subjecting something like a $500 ATI amp to amir's full battery of tests would be something I'd very much like to read. So many people are choosing these over more developed designs, using nothing more than $s/watt as a justification for purchase.

There's got to be more to it than that...

 

[GrimSurfer]

Pro is a catchall term that doesn't have any real meaning. Pro, as in project studios? Pro as in Abbey Road? Pro as in pub band PA? Pro as in Stadium rock PA? HiFi as in Schitt, HiFi as in D'Agostino?

All that distinguishes all these is the intended application and suitability for use. I happen to use project studio amps in my home Hifi as they are adequate for the task I expect them to carry out. There's no pride of ownership involved, they just work, and have done for some 6 years. Others wouldn't let them through the door as they look cheap, and indeed are cheap, yet they work fine.

I wouldn't concern myself with the Pro or Hifi label, just buy what does the job.

S

I agree with everything you said, sergeauckland.

BTW, do you live in Auckland (as per your sig?). Lovely city and so close to one of my favourite beaches (Piha)!

 

[LTig]

Pro is a catchall term that doesn't have any real meaning. Pro, as in project studios? Pro as in Abbey Road? Pro as in pub band PA? Pro as in Stadium rock PA? HiFi as in Schitt, HiFi as in D'Agostino?

All that distinguishes all these is the intended application and suitability for use. I happen to use project studio amps in my home Hifi as they are adequate for the task I expect them to carry out. There's no pride of ownership involved, they just work, and have done for some 6 years. Others wouldn't let them through the door as they look cheap, and indeed are cheap, yet they work fine.

I wouldn't concern myself with the Pro or Hifi label, just buy what does the job.

S

The most important feature of pro equipment is reliability: it must be able to handle all kinds of use and abuse without breaking, and deliver its specified performance within the specified conditions.

Since there are so many different areas where pro equipment is used there is no single set of features of pro equipment like good THD specs or else. It depends on the conditions where you want to use it. These are quite different for amplifiers for studio use and PA use. The former must have medium power, very good TDH specs and no fans while weight is not important. The latter must deliver very big power, be lightweight and extremely robust regarding mechanical abuse while on travel.