Michi P5 Preamp Tone control Distortion


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128x128lordrootman

I also find it a bit ironic that we as listeners don’t want to consider using EQ, but if you realized how extensively at least some type of EQ or spectral balance shaping techniques were used in the mixing & production process of 95% of the music that we listen to, you would be shocked.

No, I wouldn’t be shocked at all. But as I mentioned all the music I listen to on my home system is well recorded because that’s what I choose to do. If I wanna listen to a crap recording to the point that it requires EQ I’ll listen on Alexa or some cheap earbuds rather than trying to polish the turd on my home system. If a recording engineer uses EQ to achieve good results I’m fine with that and have never felt any need for tone controls whatsoever nor do I wanna add more electronics into the signal path to do so. But, if you need or like using EQ live it up. To each his own. I’ll just note that no high-end systems at audio shows use EQ. None. Why do you think that is? And why is it that very few high-end preamps or integrateds offer tone controls? Hmmm. There’s a message there somewhere. But you do you and that’s perfectly fine.

The bit about car audio is useless. Sitting right in front of the left speaker in a highly compromised space with external noise is a nonstarter for really good sound, so once again you’re just using EQ to polish the turd. Of course if you try to get car audio to sound decent for the driver any passengers are completely screwed. It’s severely compromised no matter how you slice it. So it goes.

@soix 

 

read this from recording engineer 

 

 

Interesting Read From a Recording Engineer about EQ


 

On another note, I find it strange how many audiophiles or audio enthusiasts are averse to using EQ to achieve audio bliss with a product that they feel is just a tad too bright or harsh, or needs a little boost or cut in the low end, midrange, etcetera, in order to be ideal for their preferences.

I understand that using EQ doesn't make sense if the headphones, IEMs, or speakers will require A LOT of extensive EQ to get them dialed in. But I find that most products are within a +/- 3dB range (and usually MUCH less) in a certain frequency or two to get them dialed in, which is perfectly safe and achieveable with the majority of products we use.

I also find it a bit ironic that we as listeners don't want to consider using EQ, but if you realized how extensively at least some type of EQ or spectral balance shaping techniques were used in the mixing & production process of 95% of the music that we listen to, you would be shocked.  😛

For multitracked music, strategic EQ and tonality shaping with levels are used by mixing engineers to place the various instruments and vocal(s) withing the soundstage from front to back, i.e. Depth and Layering. EQ is also used to bring vocals forward in the mix (or push them back). IOW, EQ is a Very Powerful Tool in the mixing and mastering engineer's toolbox.

Yet as audiophiles seeking audio nirvana and the best possible performance from our gear, most of us are afraid or averse to using ANY EQ whatsoever. 😕

In the recording studios these days, you will find that nearly all engineers are using and embracing at least some type of monitor speaker/room correction software (which is primarily EQ-based). In addition, several of the companies that design and manufacture highly regarded studio monitors, such as Genelec for one, are incorporating these types of measurement/analyzer/correction systems built into their products, which helps each engineer to achieve their absolute REFERENCE system for their mixing and mastering work.

Again, these are the PROFESSIONALS that are responsible for producing the music that we are listening to on a daily basis. They spend many thousands of dollars on both analog and digital outboard rack-mount EQs or DAW plugin EQs to complete their daily work. 

I first learned the true importance and the amazing power of EQ in my journey as a high-end car audio enthusiast. In a car audio system, there are at least two major factors related to the proper use of EQ that are major obstacles to achieving a tightly focused center image that does not wander or drift dependent on the immediate frequency of the vocal or instrument as the song plays, in addition to achieving a perfectly linear and balanced Left-to-Right Soundstage.

The "Depth To the Stage" (where it begins in front of you), and "Depth Of the Stage" (how deep or forward it projects beyound the speaker positions) is also highly dependent on proper Independent Left & Right EQ, which is absolutely necessary in order to produce a smooth, even, and linear frequency response that corresponds to our preferred Target Curve, AT OUR LISTENING POSITION.

# 1. In our vehicles, our Main Listening Position (MLP) is not perfectly centered between a pair of loudspeakers. This presents a huge problem, or should I say, multiple problems. Just try sitting 3 feet to the Left or Right of Center in your home setup, and also closer to the nearest side speaker as well. The SPL from the closer speakers will be significantly higher, AND, any reflections that you hear from the nearest side speaker will arrive much earlier than the opposite side speaker. I think it's obvious that the results will not be ideal, right?  😛

# 2. In a vehicle, we don't have a properly sized or acoustically treated "room" to play those nice loudspeakers in! The highly reflective near-field environment of a vehicle wreaks havoc on the frequency response at our MLP from our otherwise perfectly flat and neutral high end speaker transducers. And all of the reflections that we hear will be EARLY reflections, meaning there is not enough of a delta in time for us to perceive or differentiate the multitude of reflections from the direct sound coming from the speakers. This produces horrible comb filtering and a very erratic frequency response from our otherwise flat and neutral high-quality speaker drive units. That's not a good start!

# 3. In addition, each of the speakers in our vehicle cannot be ideally placed on a common baffle, and they usually end up being spread around the interior in seemingly random and non-ideal locations within the vehicle. Again, Each Speaker will be affected differently, dependent on its immediate environment or location (nearby reflective boundaries).

# 4. There is another factor that is not so much related to EQ per se, and that is the need for independent "Time Alignment" or digital delay for each speaker so that each one arrives at our off-center listening position in perfect sync, just as they would when sitting in the "sweet spot" equidistant between our home loudspeakers, or headphones/IEMs.

Most high-end car audio systems will have a "front stage" speaker set (equivalent to our front "mains" speakers) consisting of a Left and Right set of Tweeters, Midrange, and Midbass drivers, along with one or more subwoofers that are usually placed somewhere out of the way in the rear of the vehicle.

Because we sit Off-Center to each Left and Right group of speakers, one side is relatively On-Axis to our listening position, while the group of speakers on the opposite (near) side will likely be severely Off-Axis to our listening position. This will cause a massive difference in frequency response between the Left and Right sides, and this, in turn, will destroy any chance of achieving accurate image placement and soundstaging, as well as a pleasing, balanced, realistic and lifelike spectral balance (tonality). 

Try playing a full-range mono Pink Noise track in a non-EQ'd car audio system and quickly adjust the Balance control from full Left to full Right. The massive change in Frequency Response from the Left group of speakers will be COMPLETELY DIFFERENT from the Right group of speakers, and this will be readily apparent at our off-center listening position.

To help in this regard, we try and use a combination of speaker drive units that can play an ideal, particular passband with low distortion, and most importantly, without "beaming". Minimizing any beaming (the narrowing of dispersion as frequency rises) helps the On-Axis and Off-Axis frequency response from each speaker to be much more even and linear. We achieve this by using the appropriate Crossover Network Filters on each driver that protect the drivers while keeping them from playing into a frequency range where they will start to "beam". Ideally, we want to maintain a very even and smooth DIRECTIVITY across all of the drivers. Carefully chosen Crossover Filters are also another way to control the summed or overall Frequency Response...IOW, Crossovers can effectively function as "EQ" as well.

Remember that our off-center listening position in a car makes the On-Axis and Off-Axis Left and Right frequency response quite different. But minimizing beaming and optimizing for smooth directivity helps to even out the differences in FR between the left and right sides as much as possible. HOWEVER, we will still need LOTS of EQ to optimize and balance this Left vs. Right frequency response. This is due to the highly reflective environment of the car. There is really no way around this in a vehicle listening environment. 

Still, EQ can only do so much. Because of the unique interior dimensions of each vehicle, (in addition to obstacles such as large center consoles, transmission humps, the steering wheel, etcetera), there will be Cancellation Nulls at several particular frequencies that cannot be boosted or corrected using EQ. For example, if you try to Boost these cancellation nulls, the speakers will just be working much harder without actually producing any more output at the null frequency, and you risk damaging the speaker due to overexcursion or heat.

HOWEVER, EQ can be used to Reduce PEAKS in the response, and/or to Lower the Peaks On Either Side of the Null, which effectively smooths out the overall frequency response so it becomes less of a distraction or irritation. The SAME EQ technique can be used on Headphones and IEMs. The internal chambers and cavities in the cups of headphones or IEMs can produce cancellation nulls, as well as peaks in response at particular frequencies. Most modern designers do a very good job at minimizing these effects, but there will always be some amount of resonance or null at one or more given frequency. Use EQ to tame these as much as possible.

So in a vehicle, to achieve a lifelike, realistic frequency response that has excellent imaging and a realistic soundstage, we ABSOLUTELY NEED a multi-channel DSP that provides fully INDEPENDENT Left & Right Time Alignment (digital delay), with LOTS of P-EQ bands, and fully adjustable Network Filters/Crossovers for Each Channel. Some such DSP units made for car audio are the miniDSP C-DSP 8x12 & Harmony (with optional DIRAC Live), or various other units made by Audiotec-Fischer Helix or Brax, Audison Forza, Gladen/Mosconi Aerospace, Zapco HDSP-V, etc. miniDSP makes smaller 2-Channel or 4-Channel DSPs that achieve the same goals in home audio systems.

Without using extensive EQ in a mobile audio system, there is simply no way to achieve anything close to our home audio speaker system or our headphones & IEMs. But that same EQ can ALSO be used by us as well as studio engineers to effectively shape the characteristics of the sound to our tonal preferences, and also to improve dynamics, impact, soundstaging, realism, and overall musicality.

AND if nothing else, PLEASE REMEMBER THIS: Using proper EQ will have a MUCH LARGER EFFECT on the "CHARACTER" or Spectral Balance of your Headphones or IEMs than ANY type of "Upgraded", "High-End" CABLE!!! STOP buying expensive cables to "EQ" your goddam Headphones and IEMs!!!

Using EQ effectively is usually MUCH LESS EXPENSIVE, and often times it is FREE, as it's built-in to nearly all DAPs. And EQs or EQ plugins are available for nearly all computer-based music playback software or network streamers.

I'm not saying that Cables Do Not make a difference in SQ. I'm just saying that using EQ effectively is a much more LOGICAL approach, and nearly always less expensive. EQ is also INFINTELY ADJUSTABLE, whereas you will be stuck with the specific characteristics or properties of whatever cable you choose, and it may not be exactly what you were hoping for.

I also have no problem spending good money to choose a "better cable" for it's improved physical or cosmetic properties, such as better construction, less tangling, better comfort, ideal length, the appropriate connectors, and microphonics, etc.

But using CABLES to "EQ" your headphones, IEMs, or speakers makes absolutely no sense as long as the original cables are decent and usable. Engineers in a recording studio DO NOT immediately reach for a different cable when the spectral balance of the sound needs to be altered. They reach for their favorite EQ! 

 

@jetter I totally get what you’re saying.  I should’ve qualified my statement by saying I tend to only listen to well-recorded material, which is probably why I never feel the need for tone controls.  If using the Loki increases your listening enjoyment, well, that’s really what this is all about and Goodonya.  There’s always more than one way of doing things in this nutty hobby of ours.

I guess what I am saying is that I am occasionally using the tone controls to enhance my listening enjoyment, not to correct a weakness.

@soix 

If you’re using tone controls there’s something much more seriously wrong with your system or room that should be addressed before resorting to tone controls.  Just my $0.02 FWIW.

I tend to see only the positive of having tone controls.  I have a Schiit Lokius connected to my tape loop.  I can turn on and off the tape loop and hear exactly how the Lokius is impacting the sound versus not having it in the signal path.  I think it is a worthwhile and fun piece of equipment.

With it I can add a bit of sparkle to the highs or a touch more bass should I choose which I sometimes do.  

I tend to think of a speaker's voicing, as with any other piece of audio equipment, as that as interpreted by the designer.  So why not alter (slightly) this presentation if not 100% my preference in general or for a particular song?

Also just my $0.02 FWIW.

@pdjmwj If you’re using tone controls there’s something much more seriously wrong with your system or room that should be addressed before resorting to tone controls.  Just my $0.02 FWIW.

Hi all, know this post is old. Has this tone control issue been fixed? I'm having trouble finding any info on it.

I'm about to pull the trigger on a new P5 clearance.

Tanks..... Paul

..Interesting no reviewers or worse the factory missed it  quality control  no  and I would bet its a hardware issues and wont be fixed due to complete design issues  boy I am happy  was going to buy one..perhaps its a easy fix  its a well build unit hope its not a big issue

 


@larrymanadgn you’re exactly right I have RC1590 too and is piece of crap it will make a loud pop sound when my ceiling fan is turned on and off 
makes all this unnecessary hum noise 
aesthetically Rotel makes gorgeous looking  products especially when I compare with my previous Parasound P6  but they’re crap 
Even Rotel preamp lines carry exact same unsolved tone control humming issue as well. I had RC-1590 and RC-1572 both have same problem but no further firmware update to address it. I guess nobody cares about it ...
@lordrootman Thanks for the update; it seems to be a bad situation but I appreciate your response none the less.  Yes, not being the original owner is likely going to put me in a bad spot.

Fataxeman
Customer service sucks 
you need to return it 
it was B&W who handle Rotel and Michi product here in US but now they have a new distributor SUMIKO 
according to the SUMIKO and my Dealer all the Michi P5 with 120V has affected with tone control issues and they’re going to start working on them this month AUGUST 
your best Bet  is contact your dealer And since you’re not original is complicated 

we have Rotel Michi page in Facebook 
you can check it out   https://www.facebook.com/groups/384918068350254/?ref=shareAsk questions and actual owners may help you out 
@jiya3600 jiya3600

Did you ever get your tone control problem fixed?  

I just bought a used Michi P5 and I am not having your problem but another serious issue.  Just wondering what your experience has ultimately been with their support/customer service.

Unfortunately, I am not original owner but I'm about to go back to the person who sold me the Michi. 

Thank you 
@ron1264
can you try tone control 
you don’t have to use it just turn on and see if you can hear any distortion hissy or hum 
I Have the P5 and wasn't aware of this problem. I have never tried the tone controls, I'm surprised so many of you are using tone controls. 
@lordrootman

I just did the firmware update, did a full reset & reboot issue not resolved. I tried every single input as soon as the tone control is engaged for that particular input there is hum and distortion from both channels. The hum and distortion is not very loud but it's there no both channels.

As soon as I disengage tone control and put any input in direct mode completely silent. Don't know what to do at this time!


@jiya3600 Yes I did reset to factory but no any improvement on distortion 
do you see any improvement on distortion or noise ?

@lordrootman

Update can be done through the USB port too I forgot about it. BTW did you do a factory reset after doing the firmware update as its recommended in the manual.
@lordrootman
Thank you for the update will have to check it out, don't have a network connection near the amp so will have to get a router bridge or extender.

So I am guessing the new firmware didn't solve the problem?
@jiya3600 
theres a new software available I think version is 1.8
i download and try it same issue 

 I got this email this morning 

Hello Tony,

Please visit our web site to download software update for your Michi P5 that is intended to address the Tone Control noise issue.

Kind regards,
Tim
Bowers & Wilkins



 


@lordrootman Thank you for the update, given the current situation I am not in a panic to get it replaced and I figured this would not be an isolated issue. The pre amp is absolutely gorgeous otherwise sound quality, the built in DAC is very good the total package is beautiful and I am looking to keep it for a very long time.

Please keep me in the loop I will be contacting my dealer next week just to let them know
@jiya3600 
They ship me new replacement but the same issues update the software same issue 
they email me recently with this:

 

Hello Tony,

Sorry for the delay. Rotel have informed us there is something they are looking into that may relate to the issue you experienced. We would still like to provide you with the replacement Michi P5 and ask you to immediately notify us, if you experience the same issue that we were not able to test due to local government corona virus mandate .

Kind regards,
Tim
Bowers & Wilkins


hopefully they will figure it out I really love this preamp looks so gorgeous compare with my previous Parasound P6 lol 😂 
I have the exact same issue with my Michi P5 bought 1 month or so ago, dead silent with no tone control and hum or noise like sound from the speakers with tone control on.

Wonder if this can be fixed with a firmware update or have to swap out the unit, have to reach out to my dealer to see if their demo unit has the same issues.
When I disable tone control preamp is dead silent I have try 3 different amps different plugs different power cords
the only is disable or turn off  tone or zero volume I have try 5 different sources all the same
You did all diagnose, time to send it for service/repair

http://www.rotel.com/service
Post removed 
Thanks for the response @imhififan 
when I enable tone control and there’s nothing playing I can hear high distortion from both speakers like 8-10 feet away 
When I disable tone control preamp is dead silent I have try 3 different amps different plugs different power cords
the only is disable or turn off  tone or zero volume I have try 5 different sources all the same