true class A or push/pull(A/B) for a studio monitoring?

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Hi.

I have some experience in mixing and mastering audio with an amateur equipment, but now the challenge is more professional. I've been required to "sound engineer" an stereo mixing and a 5.1 mixing in a short film.

I'm currently reading sloane book "high power.." and lots of threads on this forum, after a while I like the sr50 from apex, also DoZ, both of them caught my attention.

Back in college or whatever the name is for engineering studies (in spain it's called university) they worshipped the "pure class A" for not having crossover distortion, that it's only one reason I strongly recall for choosing these designs.

I'm not aiming to high power rather than fidelity; THD, "etc", but for a recording studio monitoring.. which way would you go? Class A?

Forgive my mistakes in english and kind regards.
 
In my humble opinion....I would tend to think your focus should be setting up your studio..As a different choice of loudspeaker monitors, reflections within said studio...absorptive materials, etc.....will affect your accuracy by several factors..... more important than your choice of amplification.
As the loudspeaker contributes 95% of your "inaccuracies" I would think this should be your focus.
Amp choices should be far down your list of concerns.

________________________________________________________Rick........
 
Good point. I have plenty of room for the studio, even a book about studio designs from the spanish public television which was used since 1986 for reference design all over the country.
I will ask in the loudspeakers section, but i was thinking that the work flow could go in parallel, (I will build the cabinets, crossovers... well, I'll try).

I wrote once an article on amplification and man, I did not follow my own advice; start with the first and the last thing of the chain (the first being the source signal and the last the loudspeakers)
Anyway what choice about the amp?
 
As a commercial amp...(Already made!) First one that comes to my mind...Crown. These will last forever if bought new & not abused ..If you build or buy , match-up the output power to the loudspeaker. Some near-field monitors, say two-way with an 8" driver, some 200 Watts should suffice. Recall the distortion vs. Output power graphs...the distortion bottoming out at ten Watts for a 200 Watt amp......rising rates before 10W....and the higher power values rising as well.
Figuring the RMS value listening to your mixes might well be around 10W....right at the bottom of the curve.
Are you going to build a pair of monitors??.....A difficult build for sure...trying to get that perfect response...but it CAN be done.

________________________________________________________Rick........
 
I would worry about learning how to mix for picture. Is there dialogue? Is it the typical bad location recording thats noisey and off mic? If your playing music under this kind of dialogue you will have your hands full !!! Are you mixing for TV or Theatres. They should be completely different mixes ( dialogue normal goes from 76db spl to 84db spl) If you dont know what that means, forget the gear ( we monitor TV mixes during playback thru 30 year old 4" speakers (Aural tones)) and get some mixing info from the Dolby website, which will become your best friend if your serious about this.
 
I would like to own one of these crown beauties, never visited their website until now, tons of information there. About the THD+N vs power you're right, the internal thermal noise of the amp is to blame at low power and the 1%THD before clipping at the end.
If I understood that well you mean that I should mix at the lower value, just when the amp enter the more "lineal" THD+N vs power output graph. The power value to do so will depend on the total amp power, so instead of a 200w... why not build say a 20w amp and mix at 10w where the THD+N is at lower values?

About building the monitors I don't expect perfect flat response, but certainly better than my actual set, and the best aid with that will be a graphic eq, a probe microphone and software analysis (RTA for example), no doubt mistakes are introduced by the same equipment that in theory is to remove them, but nothing is ideal and a certain "flatness" could be achieved.

Certainly I'm worried on mixing for picture, I have a nice 8 track digital recorder ready to avoid worst case scenarios, but i don't think the director is ready to use close-range- pocket-mics for each character, I still haven't received the "storyboard", not even the "plot", so no idea about that, there will be meetings, but I think that my worst nightmares will become true about this issue.
Music... even the band I used to play in are responsible for the music, guess who has to record, mix and produce the music... not messy, but there are other musicians in the project and i don't want to be the producer, engineering the sound is far easier than dealing with musicians (said by an ex-musician: me)

About the places where the film is to be screened it is supposed to be a theaters, that's where the 5.1 idea came to mind, but of course there will be at least 4 different mixes. theaters capable of 5.1, simple stereo... and of course for dvd-tv the other set.

I know what spl means, and this afternoon I was reading an article from dolby about 5.1 mixes. I will read more, pretty interesting, i will read more from dolby website, thanks... .. too much pressure today, my hand hurts when it rains and i'm having a bad day anyway, thanks for the replies!

Beware of musicians!!
 
Yup. You want a system you can trust, the worst thing that can happen is that the dialogue cant be understood on other playback systems (for example a TV), and if you system is to hyper (detailed) in the uppper mids that is easily done. Instead of spending your time DIYing speakers, buy a pair and listen to TV shows and movies on them for a couple hundred hours. This should train your brain to what a mix for picture should sound like. Then mix something and listen to it on other systems. (when I used to mix TV on the large monitors, and sometimes the dialogue was barely understandable we knew that wouldnt be the case on peoples home TVs, (we said we would fix it in broadcast). We knew our system and we also watched the broadcasts to see what it would end up like.
 
Yup, agree with cbdb. Don't worry about diy for now, get yourself a good set of commercial active monitors and learn to use them. Then start thinking about building your own system, and you'll have the added advantage of something to compare them to.

Will do. There are way too many things to go wrong in this project and active close range loudspeakers are affordable these days. Any advice on which?
 
hmm I would look at used dynaudio, Mackie or adam before new M1 or at least check out the m1 before buying. I had one of the first M1 active models and I found they had a resonance problem around 53-60hz, I guess thats what happens when you use a toilet roll for a bass port. it was quite easily demonstrable with a frequency sweep (and no it wasnt the room), I sent them for warranty service and they came back the same, so I sold them and got some KRK. Good studio monitors last a very long time, so buying used really isnt an issue, particularly as by the sounds of it you need to ship whatever you buy in anyway.
 
hmm I would look at used dynaudio, Mackie or adam before new M1 or at least check out the m1 before buying. I had one of the first M1 active models and I found they had a resonance problem around 53-60hz, I guess thats what happens when you use a toilet roll for a bass port. it was quite easily demonstrable with a frequency sweep (and no it wasnt the room), I sent them for warranty service and they came back the same, so I sold them and got some KRK. Good studio monitors last a very long time, so buying used really isnt an issue, particularly as by the sounds of it you need to ship whatever you buy in anyway.

I've been looking, but I've found the active speakers a bit high prized, and right now I'm looking for these:

-Alesis Monitor One II Passive

-M-Audio AV40 II Studiophile (active)

-Superlux BES5A (active)

Krk are way too expensive for a pair.

Also cheap behringers are an option too.

For a stereo power amp I would like to build two-pure class A, even power amps are affordable, it all depends on the loudspeakers, of course. I'm still reading sloane's book so maybe I could find some low-power amp and modify it.
What about SR-50 from apex or DoZ as starters?
 
Love Crown to throw into a truck, but not for studio. Way too much distortion. You want accuracy. There are tons of very good amps available. Think of your target audience. They are going to play it back through a TV with, gasp, Bose speakers. At best with a $100 AVR from a big box store. Don't over think it. Pay attention to the speakers, cans and head amp. Spend your time in the studio, not on the bench. I am somewhat partial to 9xx series Rotels, but they may be masking things you want to hear in a studio. Aragon, Parasound, etc may be better choices. Heck, a well built gainclone may do just fine. A stack of cleaned up Haflers is actually hard to beat.
The active "pro monitor" speakers I have heard all sounded like the the garbage I built in the 70's. The only active speakers I know of that have the detail to identify mix problems cost a pile of money and don't come from catalogs. Might read what Gedees has to say. Not an endorsement as I have not heard them, but a point of view.
 
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