Analog room correction for vinyl


There seems to be quite a lot of dsp based room correction for digital but what are some analog solutions for vinyl systems? 
Thanks
jgreen19
jgreen19, simple. You use an analog to digital converter to digitize the signal coming from your phono amp then you deal with it like any other digital format. I have been doing this for some 15 to 20 years. The conversion is in 192/24. My preamp is digital and has the room correction and bass management in it. I use an external Benchmark ADC for the phono amp which is an ARC. The benefits of room control (which is really speaker control) and digital bass management far out weight the loss in the analog to digital conversion and back if any. 
Doesn't matter Digital or Analog, you're dealing with sound waves in your room. Just read this
The DEQX HDP-5 I use has a built-in A/D converter, and thus can apply its numerous DSP functions to analog as well as digital inputs.  I and a number of other members have reported in the following thread that despite the A/D and subsequent D/A conversion the HDP-5 and some other DEQX models are remarkably transparent.  And in any event our experiences mirror what Mijostyn said above about his different setup employing an external A/D converter, that the benefits outweigh the downsides, if any.

https://forum.audiogon.com/discussions/is-deqx-a-game-changer?

I should add, though, that as can be seen in that thread the very flexible and powerful capabilities of the DEQX DSP products go hand-in-hand with complexity and a significant learning curve.

Regards,
-- Al

chakster, that is simplistic to be polite not that appropriate use of acoustic treatment is not indicated, it is. But no matter how much crap you tack on your walls floors and ceiling you can not do 1/10th of what good digital room control can do like time align the individual speakers and correct frequency response so that it is absolutely identical in both channels not to mention digital bass management. I just got turned on to this program which at first glance looks pretty hot.   https://www.audiovero.de/en/acourate.php
Back to the Acourate, all the functionality is there in spades. I would have to work with it for a while to get use to it and I am not yet sure what the hardware requirements would be other than a dedicated computer, 4 DAC channels for a 2.2 system, a calibrated microphone and an ADC for converting analog sources. You would also need switching for digital sources and a unified volume control. Certainly getting it all in one unit like the Trinnov Amethyst would be a lot simpler but at first glance it looks like the Acourate is more flexible and $11K buys a lot of hardware.(the price of the Amethyst + microphone) 
@mijostyn First i don’t care about digital, i use analog only, no digital crap, i am a record collector, so vinyl only. I use what people are using in production room aka studios around the world. And i proceed with complete room analysis with Vicoustic, which is the manufacturer of the acoustic panels in Portugal (just like Gik or RPG in the USA). I also watched a lot from Acoustic Fields on youtube and i think Dennis did a great job to explain nearly everything in his videos, there are many interesting topics in his channel. However, i don’t want to transform my room into something ugly, so i’m using acoustic panels (absorbers, diffusers) that looks cool. I took some pictures when a first bunch of acoustic panels appeared on my ceiling and wall, now i have much more. I got panels for side walls too, but not mounted them yet. It is an interesting process and improvement is noticeable. Actually vicoustic charge only $50 for room analysis and everyone can apply online, but precise measurement of the room with all the furniture is necessary along with the images to get a 3D model. It was stupid to ignore it, i got 3D model and recommendations about exact placement of the different panels in my room, also all the acoustic measurements to compare (before and after). They are using special software to do that. It was very cheap and very helpful!

I recently find a huge manufacturer in China, wooden QRD diffusers can be ordered from them and the price is so cheap compared to similar products from American companies. Maybe i will order from them, it’s just natural wood. I think some US manufacturers order their panels from China. The manufacturer in China can do whatever i like, custom size is not a problem. 

Wow, great advice from everyone. Just to be clear, I have extensive room treatment in my 18 by 25 room. 6 cylindrical bass traps, multiple absorption and diffusion panels designed by a local acoustician. I’ve found that even with all the room treatment, some dsp correction improves the sound, especially in the lower frequencies. I never thought of going from my turntable through dsp but will now give it a shot.  As an alternative does anyone use analog eq as an option? If so which ones? Thanks!


Chakster, I collect records also. I hate CDs in their flimsy plastic cases. All my digital in on a hard drive. Like I said I do not care how much "crap" you put on your walls. You will NEVER get the same performance out of a system w/o digital control and any person with a computer and a calibrated microphone can show that to you in real time and I guarantee your jaw will drop 3 feet when you see what your system is actually doing particularly the difference between channels. If you don't want to learn exactly how "crappy" your system is performing and what little it takes to straighten it out fine but that does not mean others here don't want to learn about it. I can understand being a traditionalist. I prefer being an early adapter. As a hobby it is more fun. Like I said, with a little digital tweaking and a little room treatment you can throw all that other "crap" away. I apologize if you are computer phobic. We do have medicine for that:)  
I believe that Mark Levingson offered the Cello Audio Suite with lots of analog tone controls to allow room correction - tho an RTA would be required to do it right.  
There was also an early high end pre-pro from Theta that had a lot of analog tone shaping capabilities 
There seems to be quite a lot of dsp based room correction for digital but what are some analog solutions for vinyl systems?


There's a lot for digital because digital sounds so awful people are constantly incessantly running around looking for excuses and ways to make it sound slightly less awful. Oh wait, what's that? People are holding onto and loving and cherishing their digital gear for decades like they do with analog? No, that's not happening.

Another factor, its the numbers and graphs and stuff that sucks people into digital. Because it sure ain't the sound! Oh wait, what's that? The whole world is so convinced digital sounds good that when a record manages to sound pretty good they say it sounds digitally? No. They say digital sounds analog.

So anyway here's the analog solution to dsp with vinyl: adjust your VTA, adjust your VTF, adjust your speaker placement, move your subs around, move your listening chair around, try various acoustical treatments. If you were mislead into buying wire or anything else based on the band-aid (aka "system matching") approach, change them.

Not being smart. But if you are you will. This is also by the way the approach to take with digital. I mean, if you want to try against the odds to make it sound good, and not just look good on a graph.
A MiniDSP and Umik mic is probably your cheapest experiment to try room correction. 

As per how analog converted to digital then to analog sounds for you, well I personally think it defeats the purpose of vinyl (why not just digitize all your records), but at least you won't spend too much to find out.
The Mini DSP DDRC-24 unit includes Dirac software and works with analog and digital sources.  Seems a pretty good deal to me at $399

https://www.minidsp.com/products/dirac-series/ddrc-24
As an alternative does anyone use analog eq as an option?
Hey jgreen19,

I use a K-T DN360
millercarbon, since I can't believe your ears are that bad I can only assume that you have not had more than trivial exposure to more than the most basic room control systems/programs. It does not matter what the source is. We are not talking about CD resolution. The best room control systems ( really do not like that term) run in 64 bit programs 384 kHz. It is a lot more than just frequency response. As most of us know perfectly flat frequency response usually does not sound so hot. Those of us who have been working with this for a while use different response curves for different situations. As an example if the recording is to harsh (sibilant) I kick in a curve with a 3 kHz notch filter. All this can be done on the fly with a remote control. Most important is that the frequency response of both channels is exactly identical. You can not get the best imaging without this and there is no other way to do this. You will never get two loudspeakers of the same model to have exactly the same frequency response even if you put them in the same location forget about putting them in different locations. Once you are in the digital domain you can literally do anything you want without distortion of any kind. Subwoofer integration any other way is folly. You can not accurately time and phase align any other way. And, the fun of it is that you can see exactly what is going on right in front of you on the computer. You want to know what happens when you boost 10 kHz 3 db? Tell the computer what you want and have a listen. Any curve any cross over right at your disposal. A properly set up digital correction system will sound much better regardless of the program source. I think the problem is that with the best, most flexible systems there is a steep learning curve and you just have to sit down and work with it for several months to get fluid. You can also screw things up big time which I'm sure leads to some of the negative impressions. There are also other advantages. Having lived with this for 20 years or so I can walk up to a strange system and know to a large degree where it's failings are which does not mean I can fix them as usually in strict analog there is not way to do this. None of us used any of the analog EQ systems in the day as they all caused more damage than good. You can also set up a complex system without any analog crossovers at all and use any frequency or order you like. I do not have a single analog crossover in my system.  
mijostyn
... you have not had more than trivial exposure to more than the most basic room control systems/programs. It does not matter what the source is ... You can not get the best imaging without this and there is no other way to do this ... Once you are in the digital domain you can literally do anything you want without distortion of any kind. Subwoofer integration any other way is folly. You can not accurately time and phase align any other way ... A properly set up digital correction system will sound much better regardless of the program source ... Having lived with this for 20 years or so I can walk up to a strange system and know to a large degree where it's failings are ...
Do you really believe all of this, mijostyn, or do you deliberately exaggerate for emphasis?
Digital processors can't do anything about standing waves, first reflections, flutter echo etc. This is a physics of sound waves produced by the speakers in a certain room. Every specialist will advice you to use bass traps, absorbers, diffusers ... just like in any recording studios and mastering rooms.  The size of the room is important, some rooms are too bad to be a listening room (especially a small room), some are much better.  Watch Acoustic Fields channel on youtube and you will find the answers much quicker than on audiogon. 
Analog correction for vinyl is a listening party.  I'm sure most collectors see the countless albums with names written on the covers.  Attempting to continually improve the visual soap opera effect on B&W Godzilla movies just to see the wires and then state how annoying they are kills me.
chakster, there are certainly reasons to use room treatment. There are areas where it will work better than digital correction. As for standing waves digital correction will make the frequency response at the listening position flat but as you move away you are still going to get the same undulations maybe even worse at some places. Avoiding this requires room design and appropriate sub woofer set up. All this works together to achieve the best results. What DSP gives you, complete control over the entire frequency range, accurate time alignment between speakers and drivers regardless of their position in the room and complete distortion-less control over crossovers can not be done any other way. I use all three methods, actually four. I use speakers that have inherent in their design less interaction with the room, a room designed for flat bass response, room treatment at critical first reflection points and DSP control.  www.audiovero.de/en/acourate.php I encourage people to go here and download trial samples of the program and play around. 
You may want to look for ten or twelve band equalizers (or better yet parametric equalizers) from the 80's - 90's.  You can patch them into your system and equalize for the room without digital.  Not as versatile nor accurate as digital equalizing, but with no digital side effects.
DSP is great if you are domestically challenged. If you have flexibility the room acoustic treatment is better. 

It is not true that ALL soeakers are not well matched. My speakers are extremely close.

some need to stop gulping the kool-aide.
Excellent thread.
if you want a ‘room correction’ device try and find a Rives PARC it is all analogue but calculates in the digital I think - not just that but it works primarily in the bass where you get most room correction issues. Failing that consider subs by the likes of velodyn that do room correction. In the mid and treble room treatment is the way to go. If getting time alignment of drivers is what u need then go digital - you can do more with it. I am primarily analogue but I never dismiss digital
No acoustic treatment is going to solve bass issues in a room. For analog correction this is the ticket:
https://www.bhphotovideo.com/c/product/689907-REG/Millennia_NSEQ_2_NSEQ_2_Twin_Topology.html
Measure your room with REW and a calibrated mic and then correct the biggest peaks in the region below 200Hz with the NSEQ