ratten46

I'm debating between trying to buy a used mercman harness and building my own integration by cutting the wires. My question is...who has been successful in integration with the balanced differential signal coming from the head unit WITHOUT a mercman harness, and what type of wire did you use? Anyone try using UTP or STP (Cat5 type) of cable? By successful, I mean that there is no ground loop noise or other interference that needs major work. If other work was needed to eliminate noise, please also list that.

bmwproboi05

can u tell me exactly what your trying to instal? might be helpful. id ont understand this "mercman"

ratten46

There's a (former?) member of acurazine who goes by the id of "Mercman". He did a lot of evaluation and analysis of the signal coming out of the factory head unit on the 1st Gen TSX. There used to be several threads, one was called "the correct way to bypass the TSX amp", which detailed how to create a bypass adapter. This adapter basically took the pre-amp low voltage balanced differential signal from the head unit, and turned it into 2 pair of shielded/balanced RCA's. This allowed you to purchase an amplifier that accepted balanced differential input, and install aftermarket equipment using the factory head unit. Jeff (Mercman) made and sold these adapters on acurazine for a couple of years, and from the looks of it, sold a LOT of them. My understanding was that, especially on the later adapters, there was additional circuitry added that might have gotten rid of the radio interference. Jeff used shielded microphone/speaker cable in his parts, and I'm wondering if shielded Cat5 (STP) would have the same results. I'm also wondering if anyone made this cable (sans extra undocumented electronics) and had satisfactory results. Most of the former "Mercman Harness" threads have been deleted, and Jeff no longer contributes to this site, so there is little documentation left that talks about the research done, or how to do this properly. I've found a used "Mercman Harness" and I'm considering disassembling it to create a new DIY How-to document, but if this has been done successfully without his special electronics, it may not be worth my time (or the cost if I ruin part of the cable).

ratten46

And...yes, I've been following threads here for several years, but I didn't sign up for an account until last month. Odd, I know, but I didn't get my TSX until this year.

bmwproboi05

i see. go look at my post i got a signal from the back of the h.u to go to the aux of my alpine. you can use those lines to run to your amp . which as i know is the best way. you usualy dont want to get the amplified lines

bmwproboi05

also i never herd of this guy i just got my tsx.lol i wasorginaly loooking for tl

ratten46

I did read your thread, but I'm not looking to add a 2nd HU. Adding an additional device changes this enough, that it's not really answering my question. You're obviously doing the "right thing" by bringing the factory output into the "aux input" on your 2nd deck. The output to your amp, though, is still coming from your alpine deck, not the factory HU, so it's not really apples to apples. Whatever the Alpine does internally will not match my situation.

mtch

Im in a similar situation as you, in that I'm trying to decide how to pick up a clean signal for aftermarket amp. I have a question in something you stated here. Does the mercman harness allow connection to only diff. bal. input amps or does that harness allow connection to any aftermarket amps. If the factory sends a diff balanced low level signal, why would one need a "special harness" to connect to an amp that accepts diff balanced signal. I was under the impression that is you had one of those select few amps, that no other adaptor is needed.

bmwproboi05

hear what im trying to say that aux line im useing use it for your amp. so all you do is forget the alpine wireharness. thats all you'll need. the male and female conecter of the harness. nothing else. attach the power, ground, remote, illunation, dimmer. The male end of the harness that goes to the factory head unit use those spk lines for your amp.

ratten46

You need a way to connect to those "select" amps. The factory head unit has a harness that connects to the factory amp. This harness is useless for any aftermarket amp, except as a source for signal. The "mercman harness" just plugs into the factory wire in place of the amplifier, and gives you RCA type connectors to run to your aftermarket amp. In theory, you could make your own harness, but I've read about people having only partial success in this, and the "mercman", as far as I can tell, worked every time.

ratten46

I see what you're saying now. Replace my factory harness with this alpine one. Only problem would be that I still need to convert this into 4 RCAs that are long enough to get to my trunk. Might be a good starting point though. I'll check the details on that. Thanks!

bmwproboi05

lol dude. its not really an alpine harness but i guess you get the idea somewhat. you also dont need to make the line that liong..... when you get the singal use a female rca, and solder that on, and then run the longer rca you probaly have or can pick up http://www.qables.com/shop/images/fe...%202%20700.jpg. OR just get the rca extender http://www.vpi.us/vpi/images/items/rca-ff.jpg

if you dont know how to solder just find a cable that will meet your needs cut it and splice.

bmwproboi05

the lazy/smart/ rich person way

http://www.installer.com/item/displa...?it=AOEM-HON20

you wouldnt need to worry about repinning the harness so you can keep your factory streetwheel control like i did. mind do this cost like 5 times as much as how i did it

ratten46

Well, it's not quite that simple. While what you're suggesting may work, it's likely to pick up a LOT of interference on the way to the trunk. Balanced differential inputs are a 3 wire ordeal, not 2 wire like a typical RCA. You cannot ground the 3rd wire to the shield of the RCA and expect to have the same results. As a matter of fact, you essentially lose 1/2 of the signal strength when you do that. What you did, for a short run, would likely not be prone to interference, so is fine that way, but still loses half of the signal because you're probably inadvertantly grounding the 2nd wire. Even if you're not grounding the 2nd wire, there would be no shield connection, which is part of the balanced differential topology. Personally, if I'm going through the effort to do this, I want to make sure it's done right. The additional thing the "harness" does is to allow you to NOT cut the factory wires. This way you can return to stock amplification if you sell the car. I would rather spend a few extra bucks now, so I can keep my equipment later.

bmwproboi05

well if you look at the harness of our car there are only two wires . so if your idea of three3 i cant really see where that is coming from except if you count the sheilding which would make three ( positive, nerg, sheild.) overall do what makes you happy. im not affraid to loose 1/2 signal. i dont really use the factory one besides for bluetooth, and on my alpine i have it set to the point where the alpine decides what voltage boost it gets.

but like i said do how you feel. if your worried about all these thigns why not go bit one.

xaznperswaesonx

ok .. to clarify it all for you guys .. the difference with Mercman's harness is that it's a balun type. From my understanding , the balun type is usable on any type of amp. Factory signal is differential balance. hence why we need JL or RF amps (the only two amp i know), alpine's new PDX has a line balance input so it'll work also but not as well as said JL and RF.



This is from my knowledge and memory since i installed my system 3+ years ago.

Currently running OEM HU with Alpine PDX-F6 amp, ALpine SPX-137R components, JL 10W3V3-4 sub. Source wire was spliced at factory audio harness that connects to the factory amp (there's two .. i forgot which one)

xaznperswaesonx

the harness you can buy that'll work to provide the sound source to your aftermarket amp

http://www.crutchfield.com/p_1207017...&ssi=0&tp=3486

TSXChri5483

haha, this has been my life for the last 4 days, since I blew my the rear channels on my factory amp..... The above ^ harness looks like it accepts the post amp output (20 pin harness, or 'B' harness on the factory wiring diagram)...since I have verified that all the differential balanced signals coming from the HU still work, I HAVE to use the pre-amp diff balanced signals...

And from what I have been gathering over 4 days of research.....is thus...

these signals (diff balanced) need to be converted into un-balanced... i.e... Mercman's + BALUN + RCA output = signal you can carry to pretty much any after market amp....can anyone confirm this, with ut-most certainty?

I will be attempting to make my own Mercman's, it seems too simple except for one very important part.....what to do with the 4 SPKRGRND wires coming off the 14 pin connector... always something un-answered... can these be connected together and grounded to the chasis? do you send them to the trunk and ground them to the aftermarket amp? Do you need a ground loop isolater? Or is it best to just buy something like the JL Cleansweep http://www.hifisoundconnection.com/S...id/0/SFV/30046 for $200, acquire the AUX (approx: $134 on eBay) input along with post amp signals to take to any aftermarket amp, and call it a day?

Also, I am under the impression that the YLW/GRN wire out of the 14 pin connector can be used as REM, http://img70.imageshack.us/f/acuratsx161bj8.jpg/ and that the ground wire for the factory amp does not need to be reconnected to anything, since the aftermarket will have it's own ground in the trunk.... also, they make aftermarket LOCs that have just one ground? why would they do that? This is leads me to be believe that all 4 grounds can be connected and grounded, somewhere. confusing. http://milo.com/aamp-of-america-inc-...tput-converter, if my Mercman fails, I will probably just buy this little guy.... http://www.qualitymobilevideo.com/73-1721.aspx

I bought the IVSE61, but returned it after coming across an outdated thread stating the pre amps out of the HU were all-set for aftermarket use in any amp, looks like I may need to go and re-purchase it at Best Buy for $51... i know, terrible place, but at least returns are easy...

Let me know if I am lost with any of my assumptions, hope some of this at least helps a little.

tmcao55

To the OP:

I doubt that anyone has integrated the stock wires without noise. Ive tried many times using high quality sheilded mic cable.

Dont waste your time building the mercman harness. You wont be able to do it without noise. The instructions mercman gave on this forum were only partial. I have bought his harness and there is some type of simple circuitry he used. Ive never bothered to open it up because he hot glued over all of it. I know in the RCA head there is a capicitor or some type of electrical component connecting the inner and outer RCA contacts. The third "shield" wire is probably grounded at the harness end.

You might want to contact Fuess on here. I believe he was able to integrate the stock wires with little noise.

tmcao55

The signal from the factory HU is differential balanced. You will need a balun or a device to convert it to unbalanced to use amps with out differential inputs. 100% sure on that.

Dont waste your time building the mercman harness you will most likely still have noise. There is additional circuitry that his harness had that he didnt disclose on this forum. I know that the 4 'guard' or 'shield' wires in his harness are not grounded at the amp. I have his harness and when i open the RCA up there is only 2 wires connect to the contacts along with an electriccal component between the 2 contacts.

ratten46

Agreed. I found a used Mercman harness, purchased it, and have done a little analysis myself. From what I can see, there is definitely some circuitry built into this harness. There is solder on the circuit board that indicates that there are several components installed on the other side. He's not using ALL of the shield/ground wires. It looks like he's only tapping one of them...what happens after that, I haven't taken the time to find out yet. There is a small electronic component on the RCA end...I haven't taken a magnifying glass to figure out exactly what it is yet, but it does look like a capacitor - might be to elimiate a certain interference that was found.

To the point of xaznperswaesonx, this is NOT a BALUN. That is a different component that Mercman developed to allow you to use any amplifier. This is only a harness that allows you to connect to a differential balanced amplifier.

TSXChri5483

I am willing to bet that those components are mini 1:1 transformers..... for ground loop isolation.

I have been reading a LOT of threads with ppl complaining about noise from the engine, seems to be because no one isolates the audio ground from the amplifier ground.

I could try to explain it..... but I would do a terrible job, these might help if anyone wants to learn themselves some circuitry...

http://www.bcae1.com/glisoltr.htm

Not an audio system, but good visual to illustrate concept...

http://www.bapihvac.com/CatalogPDFs/...ound_Loops.pdf

Not sure ppl didn't already know this stuff, here to help.

The audio wires out of the HU cannot be grounded to the car's chassis after leaving the HU, or the point of reference is lost, and you get interference from other sources within the car. The audio signals are grounded to the head unit and should stay that way.

Ratten, when you get a chance to look into the Mercamn some more, please provide more information of what's going on with it?

From my understanding of an isolator, the transformer needs to be placed between the input and output and not on one of the ends...but I did fail my electrical engineering class in college first time round, always hated electrical, may be something simple with circuitry that I am overlooking... or... I'm completely wrong, and Merc did some crazy ninja-smart fabrication for his harness that I will never figure out, and now he visits this site only to read threads like mine and laugh at my outrageous feebleness for not figuring out his stupid harness yet.... ahhh!.... haha

mercman

I’m still here and I still contribute to this site, I have a 2nd Gen TSX ELS and I spend most of my time in the 2nd gen section. I am working on the 2nd gen base and ELS audio systems. I am also working with someone to make a 1st gen solution available in either a harness or converter box or combination.

I don’t sell anything on AZ since I am no longer a vendor.

Jeff

mercman

As I have stated previously, my original post four years ago was intended to correct all the misinformation about adding amps to the TSX system. The post was intended as an explanation on how to connect a balanced amp (like the JL) to the factory HU and why you could not use an unbalanced amp like the Alpine. TAMCO55’s accusation that I left information out of the post is wrong and misleading as is the statement that I sold “lots of them”. The reality is that after I created the post and I had requests from members to build harnesses for them so I became a vendor on AZ to do so. Some time after this, some people were experiencing noise with the harness, after some research I found a way to match the harness to the HU to improve the sound. I continued to research to improve the quality of the sound from both the harness and the interface adapter. After awhile I decided to stop being a vendor since I wasn’t selling “lots of them”.

I am not a manufacturer or vendor, I am an electronics engineer that enjoys high end audio and happens to drive a TSX. Just like a manufacturer, I expect that AZ will respect my intellectual property and not permit my design to be reverse engineered on this site.

I am working to get harnesses and/or adapters built and made available on the internet, I have someone interested in doing this and we are working out the details as well as trying to figure out the best approach, my “purest” approach or the “mass appeal” approach.

Please be patient and respect my work.

Jeff

jdm05CL9

i'm trying to install a 4ch amp for my mids and highs using the stock hu, can someone help?

TSXChri5483

The Mercman... no kidding... i have to say, after scouring the internet for a few weeks now, and as a fellow engineer, I can definitely respect your time and effort put into figuring this out. I thought it would be much simpler, yet every new site I read regarding circuitry or audio opens up a new can of worms... typical... shoulda have study ELE more, and seen it coming, thought I would have no problem...

(almost seems like it will cost as much to buy legitimate literature on electronics, than to sell all that I have bought, and buy a damn balanced input amp....)

But... I think I have my solution, and I have settled on a device that will take the balanced signals to unbalnced... just concerned about voltage... and starngely... Hz at low volumes, the output, overall, fom the HU seems odd... especially after reading a lot about balanced audio, is there any way you would be willing to answer more questions?

Post here to let us know when said design is up for sale and where to find it.

ratten46

The purpose of my original post was only that the original "mercman harness" has not been available for purchase for a quite a while, and I was looking to integrate a solution of similar quality. I have since found a used harness, purchased it, took it apart and reassembled it. My original intent was to post my findings here BECAUSE there are no longer any notes to be found on this site that explain how to integrate with the factory harness. I do respect Jeff's intellectual property (even if there isn't a formal patent on it). I don't know what Jeff considers to be OK to post and what is not OK, because his original explanations are not available. I will say this: the cable and circuitry is not complicated at all, but it probably took a lot of research and trial and error to determine the proper values.

It looks like the "RCA" cable used is shielded and impedence-matched but NOT twisted pair (which we already suspected/knew). I do still wonder if STP cable (such as a shielded cat5 cable) would work as well or better in this application. I would like to explain what is done with the ground from this cable, but I'm not sure if this is one of Jeff's ancient secrets.

I guess I have a problem with the idea of "intellectual property" when there is no patent and this solution isn't being produced for sale. How are we supposed to integrate this when nobody is offering the solution?

mercman

I want to be very clear on this point, no one has my permission or the right to disclose any information about the configuration or make up of my harness. I expect that AZ would lock/delete any post containing such information as they would if someone was pirating SW or attempting to copy any product. I have spoken to a lawyer in the past on this subject and my “mercman harness” is my intellectual property and is protected by US law.

Why am I being such a PITA on this, well it’s simple really, I was working with a manufacturer to get harnesses built and available on the internet when the first “lets copy the mercman harness” incident occurred. Because of this issue the manufacture decided not to go forward with the investment required to build them. Now a year or so later, I have someone else interested in building harnesses and here we go again! I have entered a “non disclosure agreement" with the manufacturer about the configuration of the harness and a post on the “net” will violate the terms of the agreement. The result of this is that the harnesses won’t get built. It is obvious that the aftermarket is not interested in the TSX so my designs are your only options. I also recognize the desire to mod and that is why I have not abandoned my attempts to get someone to build my solutions in quantity. Please remember, modifying is a privilege not a “Right”, just because I don’t make the harness to allow you to “mod” your system you don’t have the Right to copy it.

I have no interest in building harnesses for profit; my interest is protecting my design(s) and my reputation and I intend to do so.

There are a lot of technical aspects to extending the TSX HU outputs to the trunk, as is now obvious, you can just splice on RCAs and plug in. The configuration and component values used vary depending on the cable type and even component types and PCB layout. Just because two electronic components have the same value 10pf for instance doesn’t mean they will perform the same in a given application. So, even if you copy the component values in the harness you will have no way to tell if you have fixed the issue or created new ones. It is possible that you can start the HU into high frequency oscillations that will eventually burn out the output devices or cause problems for other electronic devices nearby. This can happen just by using the wrong wire, components or a wiring error. These problems may not so up as sound issues so you will never know without test equipment.

It should be clear my reasons, it should also be clear that I am not withholding the information so I can profit from building cables. If I wanted to profit from building cables you would be able to buy one from me. I withhold the information because it can do more harm then good; it is not a DIY project for a car audio installer with parts from the local Radio Shack. Case in point, the cable is “twisted pair” it just has a different TPI value the CAT 5. The TPI impacts the capacitance and in the inductance of the cable.

You will have a 1st Gen TSX solution available soon, just please be patient, it costs a lot of money buy materials and get this built and tested.

Jeff

ratten46

Jeff, thank you for your reply. I don't plan to continue this thread, as far as I am concerned it can be locked. I searched and scoured the forums for this type of reassurance as posted by you in this thread, however every link that appeared to have good information had been deleted. The ones that remained were tainted by (false?) accusations that had not been responded to by you. I tried to send you messages on other forums, but never got any response, and it seemed that others had the same issue. As you can see on this thread, many people haven't even heard of your harness and knew nothing of the proper way to interface with the factory HU. So, I assumed that you no longer had any interest or intent to continue with the Gen 1 TSX solution. My only intent was to try to continue where it seemed you may have left off. You've given out more information in this thread than I had even planned to give out myself. The reason for this is because although I found the basic values of the components, I did not have a full understanding of how and why they were implemented in the manner they were, and don't have access to the equipment I'm sure you used to create the solution. Case in point - I didn't even think about how TPI would impact inductance, but it's obvious it would have an impact, now that you've stated it - and each pair in Cat5 has a different value.

Please accept my apologies on this thread, as there was no harm intended. I will "cease and decist" this activity and conversation.

feuss2

iTrader: (1)

You can call things heresay, accusations, etc, but it is pretty hard to argue with the facts:

• You posted incomplete instuctions
• As members followed them and had noisey installations, you send them double/triple checking their wiring, all the while knowing there was something missing from their harness
• When people posted their problematic installs looking for help, you took the opportunity to point out to people how hard it is to build a harness

After a cumulative loss of hundreds of dollars and countless hours by the community you've mislead, you ultimately admitted that the harness you sold contained a noise circuit that your instructions did not. The moderators of this forum got this information, gave you a chance to make things right, and you refused. The result was:

• Your amp bypassing thread was deleted
• You were banned

mercman

You have a right to believe in any conspiracy theory you want but you don’t have a right to accuse me of wrong doing. The reality is that out of everyone I have ever helped here you are the only one to have a problem with me, let’s see if we can find out why?

You asked me to supply you with a schematic of the interface converter so you could build your own. I said no, could that be it, I wonder?

Then you attempted to DIY your own harness and couldn’t get it to work, then claimed the instructions were wrong and everyone was having issues, funny, you are the only one to ever claim that. You say there are lot’s who tried and failed because I deliberately mislead them so they would be forced to buy a harness from me. Again, a very elaborate plot, I wish I had thought of it. You got so mad because I wasn’t helping you fast enough that you bitched to the mods, got your buddy to go along with your story even if he didn’t try to make his own harness and succeeded in getting me banned. Turns out your buddy was only trying to add a sub and my post never even mentioned a sub only install. Then while I was banned you were emailing me and I was nice enough to try and help you sort out your issues, you never mentioned that, however I will mention that you were using some odd-ball esoteric cable, not following the instructions.

So you feel somehow entitled to copy my work and have me provide the parts lists? Well I’ll do one better, how about I post the PCB art work and give you my account details at the factory so you can order your own boards and charge them to me? While I’m at it, I’ll post all my schematics for my Honda audio solutions so you can copy them, just in case you jump to an 09 TSX or other Honda. You will need my ELS HU simulator program for your laptop and my MCU program for the preamp, but what the hell, were all friends here right?

Oh, I have a question for you, if your DIY harness is so bad how is it that you can drive around with it for the last two years, anyone else would have torn it out and gone back to stock? It sounds a little fishy from where I sit.

I have told you this before but it is worth repeating,

The original post was to correct the shop install instructions posted in the FAQ section. The shop install instruction paid no mind to the fact that the output was balanced.
I posted some pictures of my first homemade harness and what I did for my 06. I had no noise issues with the 06. Most people that looked at the thread realized that it was not a DIY project and started asking me if I could build them. I became a vendor and did that for a while. So after building a few harnesses there were some complaints about noise, after some research I found the source of the noise was the HU, I redesigned the harness and PCB, added some components to compensate the HU and the issue went away. Basically, the redesigned harness looks nothing like my original, but if I connect my original I still will get no noise.

You mentioned the money wasted by everyone; again, it is just you. You do not mention the money I have spent for all of this, or, does that not matter? Oh that’s right, it’s all about you…

“You will get more flies with honey then you will with vinegar”

To everyone else that is wondering about all this, basically, it is not possible for the home DIY’r or a shop to make a noise free connection to the HU without parts including a PCB that you can’t buy a Radio Shack. As I have said before, this is not DIY project, I’m sorry, but when I started this I thought it was.



Jeff