Hi Raul, I have a question for you and I need your help. I am looking to design my first $25,000 phono preamp. I have a few problems in the design stage but I think I got it sounding pretty good. The problem is the freq response. You can see the responses I get from several different changes in design. I like the deep blue line it sounds the best to me. The problem is it is the worst looking response. What should I do?
Also, is this a flat enough response plus 9db and minus 40db for a $25,000 preamp? You did do measurements, didn,t you? You should know and you should know the reason why.
Another thing I would like to know is why would you need a flat response in a phono preamp any way? Just what does it matter if the freq response is off like that, I mean if it sounds good right, who cares? Tell me what it means to not have a good freq response? What does it do to your music? If it does nothing, don't worry about it. But if it does something its probably something to worry about. And it does not matter if it is in the phono preamp, cartridge, amps, speakers or ROOM. If it does not measure good it can't sound good. And the reason why is because when you are missing freq you are missing music, when you are boosting freq you are coloring the music. It does not matter where those freq are boosted or decreased in your system it is freq error and plus/minus 9-35db is unacceptable!
Are you testing your equipment that you are designing with an amp that has a 9-35db freq response aberation? I hope not! Are you testing your equipment with an in room response of 9-35db? I hope not! So just how do you know you have a great room or a great $25,000 phono preamp unless you measure it. Because it sounds good? How can it sound good if it doesn't measure good? How can you be so worried about IMD and completly forget about freq response its only more part of the puzzle. Tell me how to fix IMD. And in the meantime I will tell you how to fix your freq response and clean up your IMD at the same time. That sounds like a good deal to me.
You said, "here is where exist that IM/HD that gives heavy distortions in what we hear ( there is no perfect driver: moving coil, electrostatic, ribbon, etc.. The speaker designers has to choose the best " trade offs ", but the distortions are there. ): less clarity, less resolution, less precision, less natural balance, less pitch, les, less, less......., and this is what we are really hearing: LESS MUSIC."
YES you are hearing LESS MUSIC if your freq response is plus/minus 9-35db. A freq error is distortion and one we can minimize. If your freq response is off at any point it is undesirable And I say within plus or minus max 2.5db. And as you get closer you do get to realise there is no perfect component or perhaps there is. But at least you are hearing all that your system has got, perhaps even for better or for worse.
And you also said, "I already point it out that IMHO the most important improvement that we can/could have adding a pair of true stereo way subwoofers is to lower the intermodulation distortion on the main spekaers, in this way you don't only have ( for the first time ) true undistorted low bass response ( that when you hear it for the first time it will be extremly hard to live with out it. ) but you clean up all the whole system frequency response: mid bass, midrange and high frequencies, that give to us several advantages : lower distortion response, lower coloration, higher accuracy response, better dynamics, improve over all the sounstage/imagin/focus, improve on inner detail perception, etc, etc that at the " end of the day " can(could take us nearer to the recording and nearer to the live event."
Raul, YES EXACTLY!!! That is what a flatter freq response gives you. lower distortion because you are not overdriving speakers (OH believe me, we can get into that later), lower coloration there are no peaks to obscure other freq or dips to hide details, those are colorations, improve overall soundstage, image, focus etc this is obtained when you room has a good decay time, just another benefit to bass traps, improve dynamics and inner detail sure how can you have inner detail and dynamics when half of the music is missing and the other half is obscuing detail by overpowering music that is 60db below it. When your system is plus/minus9-35 db, it does not matter where the problem is and if its in the room you have got to fix the room. The good thing is you can fix the biggest detriment to great sound.
Yea, The Emperor Wears No Clothes.
Bob
