2nd Order Harmonics

Ratcatcher

New member
Hello all,

First off, apologies as i know nothing about studio recording but hence the reason im here to hopefully find some answers!

Im lucky enough to have a large barn at my disposal which i use as a workshop and in a fit of madness i installed a 3kw RCF pa rig to play music and for the occasional party. Unfortunately, as i come from a valve hifi background, i generally find the sound a bit harsh and sterile. Im using a dbx 31 band graphic to fiddle with the mid range but i would really like to add some even harmonics to soften and add some richness to the sound.

Ive had a quick look on ebay and very quickly got out of my depth with the plethora of studio processors available. So the question is, what do i need? It obviously needs to be stereo unit and most certainly doesnt need to be complicated or state of the art (ie expensive). What do you suggest?

Thanks.
 
I suggest you go and listen to some different PA rigs! If those (1.5kW each?) RCF speakers have compression tweeters they can indeed sound harsh, especially when pushed.

The idea that "valves are good because they produce even harmonics" is largely a myth. Most serious valve power amps are push-pull and that circuit configuration cancels a good deal of even harmonics so, especially when hit hard such amplifiers are mainly giving a mix of distortions and mainly 3rd and higher.

WTGR I think your lack of love for the present PA system is due to the speakers and possibly less than stellar power amps. There are many, many all solid state studio monitors and PA rigs that produce loud but sublime sound. They tend to be expensive tho'but.

Dave.
 
I suggest you go and listen to some different PA rigs! If those (1.5kW each?) RCF speakers have compression tweeters they can indeed sound harsh, especially when pushed.

The idea that "valves are good because they produce even harmonics" is largely a myth. Most serious valve power amps are push-pull and that circuit configuration cancels a good deal of even harmonics so, especially when hit hard such amplifiers are mainly giving a mix of distortions and mainly 3rd and higher.

WTGR I think your lack of love for the present PA system is due to the speakers and possibly less than stellar power amps. There are many, many all solid state studio monitors and PA rigs that produce loud but sublime sound. They tend to be expensive tho'but.

Dave.

At the risk of upsetting the apple cart, im afraid id have to disagree with your statement of 'serious' power amps. PP amps are in general higher powered for sure, but my preference is for SET and, as you might guess, the accompanying 'warmth' that comes with them. Horses for courses, and different configurations have their fans. FWIW, I also own a pair of parallel set 211 amps with 50w a side, as well as some el34 pp amps and i like them both in different situations, but im not particularly impressed with PP amps over 50w.

Agree, that my RCF rig isnt the last word in quality but for now im stuck with them. I suppose im trying to fudge over the problem rather than address the root cause, but so long as it offers a quick fix in the interim, then im for it!!

PS rig is active.
 
At the risk of upsetting the apple cart, im afraid id have to disagree with your statement of 'serious' power amps. PP amps are in general higher powered for sure, but my preference is for SET and, as you might guess, the accompanying 'warmth' that comes with them. Horses for courses, and different configurations have their fans. FWIW, I also own a pair of parallel set 211 amps with 50w a side, as well as some el34 pp amps and i like them both in different situations, but im not particularly impressed with PP amps over 50w.

Agree, that my RCF rig isnt the last word in quality but for now im stuck with them. I suppose im trying to fudge over the problem rather than address the root cause, but so long as it offers a quick fix in the interim, then im for it!!

PS rig is active.

To me the whole Triode amplifier thing is a nonsense. The "tweaks" use triodes because they shun pentodes for their higher distortion and HEAVEN FORFEND they should use corrective feedback. Then, having GOT the lower distortion they glory in the even (sort of) harmonics!
To me any kind of distortion is unacceptable. It is now quite possible to build bipolar transistor amplifiers whose distortion products at 100watts+ are lost in a -100dB noise floor. I respect your position but it is SO far out of my ideas of excellence in sound reproduction that I shall leave you to it.

The guitar amplifier is a different matter but even here valves are being ousted and the "punters" cannot tell!

However, you seem a chap handy with a solder iron? Knock up a preamp with an ECC83 section per channel. You can frigg about with the cathode resistor and get it a bit less linear than it usually is.

Rock on friend.

Dave.
 
Hello, My music room is also located in a barn. I have outputs from my interface feeding my pa , as well as my studio monitors. I have to eq the hell out of my pa to get it to sound "Anywhere" close to my monitors, and then it's still in mono. I'll power up the pa and prop open my studio door, just to listen to something if I'm working in the barn. Without having my monitors for reference I'm sure it would sound much worse. EQ?, Mono?, Bad acoustics in a barn? good luck... Mark
 
I would bring in more hay and a few cows to soften the harmonics.
I think the brown/white milk cows offer the warmest response...but whatever is common in your area.
 
In a recording environment, the object for many is the quest for accurate sound, with the highest signal to noise and no distortion - or as close to no distortion as is possible. On replay, the public can mangle this in any way they like - playing through terrible home stereos, laptops, bluetooth speakers, plus the audiophiles interpretation of selected distortion that makes sound better. Frankly, I don't care which level replay is carried out at, but any deviation from the sound I create is a backwards step from my perspective, but I respect listeners who routinely set up a smiley face on a graphic, or turn the treble right down because they don't like top end. I cannot cope with the notion that I should deliberately reduce the quality of my recordings in a way that changes them. My time with the broadcasters convinced me that putting resources into some areas is just poor use of it. The valve/tube amps, the clever cables, the precious metal coatings etc just get no look in at the broadcast production end, yet a few consumers spend a fortune putting it in? For PA, the notion of tube amps is a non-starter. PA gear is rarely designed specifically for install - there are of course a few products, but the majority are designed for multiple purposes - and you don't truck tubes around if you are sensible. Yes - I realise that guitar amps have tubes and distort in a nice way, but they are producing a 'sound'. For replay and live use, amps and speakers really need to be transparent. tweaking the sound passing through is treatment, and best done, if you must, at the mixer end. Most PA speakers mangle the sound to a degree in anything other than the most expensive offerings. They can't even manage flat frequency responses, and often the ones that look flat also sound terrible. Mark above summed it up. PAs just don't sound remotely like monitor speakers, even the good ones!
 
With a 31 band EQ you are better off to subtract the frequencies that you don't like rather than try to add the frequencies you do like. It's been many years since I have added anything on a 31 band EQ.

Alan.
 
In a recording environment, the object for many is the quest for accurate sound, with the highest signal to noise and no distortion - or as close to no distortion as is possible. On replay, the public can mangle this in any way they like - playing through terrible home stereos, laptops, bluetooth speakers, plus the audiophiles interpretation of selected distortion that makes sound better. Frankly, I don't care which level replay is carried out at, but any deviation from the sound I create is a backwards step from my perspective, but I respect listeners who routinely set up a smiley face on a graphic, or turn the treble right down because they don't like top end. I cannot cope with the notion that I should deliberately reduce the quality of my recordings in a way that changes them. My time with the broadcasters convinced me that putting resources into some areas is just poor use of it. The valve/tube amps, the clever cables, the precious metal coatings etc just get no look in at the broadcast production end, yet a few consumers spend a fortune putting it in? For PA, the notion of tube amps is a non-starter. PA gear is rarely designed specifically for install - there are of course a few products, but the majority are designed for multiple purposes - and you don't truck tubes around if you are sensible. Yes - I realise that guitar amps have tubes and distort in a nice way, but they are producing a 'sound'. For replay and live use, amps and speakers really need to be transparent. tweaking the sound passing through is treatment, and best done, if you must, at the mixer end. Most PA speakers mangle the sound to a degree in anything other than the most expensive offerings. They can't even manage flat frequency responses, and often the ones that look flat also sound terrible. Mark above summed it up. PAs just don't sound remotely like monitor speakers, even the good ones!

I dont really want this thread to be a chest banging exercise for the purists. Ive heard all these arguments before and although i dont completely agree with them, i do actually 'get' it and (albeit begrudgingly) respect it.

Im also fully aware of the limitations of my PA. A quality playback system it is not. BUT, if possible, i want to change the sound, in essence put an effects pedal inline to make it more palatable. If this goes against your ethos/beliefs/karma/mojo or whatever, i dont particularly care........all im asking is if something like that actually exists. It may be complete sh*t and make everything far worse, but hey, nothing ventured etc etc.....

And yeah, cost is REALLY important.......:)
 
I dont really want this thread to be a chest banging exercise for the purists. Ive heard all these arguments before and although i dont completely agree with them, i do actually 'get' it and (albeit begrudgingly) respect it.

Im also fully aware of the limitations of my PA. A quality playback system it is not. BUT, if possible, i want to change the sound, in essence put an effects pedal inline to make it more palatable. If this goes against your ethos/beliefs/karma/mojo or whatever, i dont particularly care........all im asking is if something like that actually exists. It may be complete sh*t and make everything far worse, but hey, nothing ventured etc etc.....

And yeah, cost is REALLY important.......:)

I like to think it is not "purism" but Truth, that is surely the basic meaning of High Fidelity?

However, you are it seems firmly in the "Subjectivist/Tweak" camp so I shall suggest (shameless spam) one of the Blackstar HT series of pedals. Cascaded 83 sections. Yes, op amps (but you have dozens for and aft anyway) but they only do transparent level lifting and EQ. The valve can be driven from clean to total mayhem and all the harmonics are valve generated.

Oh! You will need two for stereo.

Dave.
 
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