Microphone Mod

[Cheap!]

Problem; Everyone can hear me on the BT phone over the in car microphone but since my wife is soft spoken and she is in the passenger seat hardly anyone can hear her.

Solution; Install two mic's up there.

Problem; Lots of questions.

Solution; Ask the great folks at Priuschat.com

Pros; People will finaly be able to hear my wife in the car too and that would make her happy.

Cons; If it can be done, it will cost around $70.00 to do the way I have priced it, and that would make her mad. Then I will be sad.

Here is what I have so far:
I always wanted to know what was behind the vent holes on the passenger side.
[attachmentid=5247]

After unscrewing two screws from the eyeglass holder area (Not Shown), pull down on the right side.
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Remove the clip holden the overhead lights to the roof. (Bad picture.)
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Remove the lamps/bulbs.
[attachmentid=5250]

Remove three more screws.
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Pull up the back of the board about a half inch and then pull it back and away from you to free it. You can see where the mic sits now.
[attachmentid=5257]

Notice the clip is a holder that would work on U.S. and Euro Prius.
[attachmentid=5253]

This is the box your after. You have to do the two clip on the underside with a flathead screwdriver first.
[attachmentid=5254]

Now you can see the Mic Amp board. This is the best picture I have of the mic connector.
[attachmentid=5255]

Here is the microphone.
[attachmentid=5258]

My dealer’s part department gave me these part numbers for a replacement microphone with microphone amp. So that would include the black box also.
Part number = 8625047020 or 8625047040?
I went out to find another microphone and while I was out I started to think that I might want to go with the official Toyota part on this mod for sound quality.

Well do you want to be part of a Prius-Think-Tank? Or would that be Prius-Think-Bladder? Anyway, here is what I need help with.

1. Can two microphones be hooked in parallel without any trouble?
2. How can I pull the pins from this clip so I can solder a second microphone to it?
3. What is the correct part number?
4. Can we find a source of this exact microphone without the microphone amp?
5. Is there a source for a dearly departed Prius where I could get just the working microphone for less then the $70.00?
6. Should I install a mini pushbutton on/off switch to turn on and off that microphone? I am thinking I can come back to that later and if I do I want to figure out how to hide that in the eye glass holder so you can’t see it under normal circumstances.
7. Can you think of any problems with this mod that you think can’t be overcome?
8. Is there anything you can think of that I have not though of.

Thanks in advance for your help. If I have to, I will save my lunch money to get the $70.00 but I thought someone might know a source.

[TJandGENESIS]

<div class='quotetop'>QUOTE(Cheap! @ Oct 12 2006, 12:18 AM) [snapback]331560[/snapback]</div>

1. Can two microphones be hooked in parallel without any trouble?
Thanks in advance for your help. If I have to, I will save my lunch money to get the $70.00 but I thought someone might know a source.
[/b]

I don't have all your answers, but I am fairly certain you can not hook two mics up the way you describe. At least, I think you would have some sort of feedback issues.

I may be wrong.

[Cheap!]

TJandGENESIS,

Thanks.

This is what I was talking about. You submitted a question to me that made a light go on in my head. Google for "two microphones in parallel" and look what I found.

The following microphone techniques can be used to capture the live "soundstage":

The X-Y technique involves the coincident placement of two directional (cardioid) microphones. When two directional microphones are placed coincidentally, typically at a 90° angle (or greater) to each other (typically with each microphone pointing to a side of the soundstage), a stereo effect is achieved simply through intensity differences between the sound entering each microphone. Due to the lack of time-of-arrival stereo information, the stereo effect in X-Y recordings has less ambience. The main advantage is that the signal is mono-compatible, i.e., the signal is suitable for playback on non-stereo devices such as AM radio. If two bi-directional (figure 8) microphones are used instead of cardioid microphones, this technique is known as a Blumlein pair . Angles for microphones are: 90° - bidirectional, 131° - cardioid, 105° - hypercardioid, 115° - supercardioid.

Since the Prius mic is directional (cardioid) , and they will be pointing more than 90° from each other, this should work.


Now I need to look up "Blumlein Pair." I don't know what that is, but I had a blooming onion once.

[eagle33199]

1. Very good question. doing a little research on microphones at wikipedia, it appears that there are different types of microphones. some operate by producing a voltage difference across their terminals. others work by producing a current. If this type of mic operates by producing a voltage difference, then there shouldn't be a problem hooking them up in parallel. if, however, they operate by producing a current, then you would not want to put them in parallel (although maybe in series would still work? not sure about that one)

2. I wouldn't pull the pins from the clip - they may prove extremely difficult to get back in. Instead, i would carefully cut open the blue wrap and extract the wires. you can then cut them and solder as need be, and then just reattach it to the board (since the connector is still there).

3. Your guess is as good as mine. maybe one is for the Mic and one for the amp board?

4. I doubt you would need the exact microphone - instead, you need one that operates in the same manor with the same response range (in terms of voltage or current). So you would have to figure out what the specs are on this microphone.

Idea: is there a manufacturer or ID number on the microphone or amp board? if so, you might be able to get specs from them.

5. Check e-bay There are sources out there for Prius parts, however those mostly involve the higher cost parts (computers, batteries, ect). If you can find someone with those parts, they may be able to pull the microphone for you.

6. An on/off switch would probably be a good idea. I'm thinking that with two microphones in the car, you may end up with an echo you don't want. Since you say you speak loudly enough for the Mic, it may just be that when your wife is with you you'll want to switch microphones and speak up a little more yourself.

Also, if the microphones are current based (and not voltage based) then i think you may need to be able to switch between them (put them on a DPDT switch, so only one is "connected" to the system at a time). this would prevent you from introducing too much current and blowing something.

7. Anything can be overcome with enough thought (and money). As indicated above, i think some more research needs to be done, focusing on the type of microphone being used, it's properties, and the kind of response you'll get depending on where you place the second microphone in the car.

8. Yes (see above for most of it). Lastly, you'll want to avoid feedback (current flowing into a microphone where it shouldn't be). I'm not positive that i fully understand how a microphone works (i've never really studied them), but it appears that the voltage microphones may create both positive and negative voltages, which would cause you a problem. Even with diode's to prevent feedback, you wouldn't be getting the full waves from the microphone. think of it like this: Each microphone produces a sine wave, slightly offset from each other. with the diodes, the two waves would join together, taking whichever one has a higher value. this would give you a distorted wave, which means your voice would sound distorted.

Of course, this is all conjecture - i haven't studied microphones and can't be sure i fully understand their operation. however, due to the posibility (maybe even likelihood?) of distortion from adding a second mic like this, i would highly suggest putting them through a DPDT switch. the switch would allow one microphone at a time to be turned on, preventing pretty much any other problems.

What may actually be a little better would be to look at positioning the current microphone differently. If you can figure out where the wires from that little amp circuit go (probably down one of the pillars and then into a computer), it may be possible to remount the microphone somewhere out front, like the center speaker grill, then just tap it into those wires down there. Since voice normally projects forwards (and not up where the microphone currently is), you could potentially get better reception of your wife's voice there.

regardless, i think everyone here would be interested in the results of whatever you do, as well as more detailed pictures (man, i love pictures).

[Cheap!]

This should take care of questions 2, 4 , and 5.

I just got off the phone with the dealer and I went ahead and ordered the part for $68.26/plus tax. BOHICA! It should be in on Wednesday. I will take pictures of the actual install with closer pictures of the duel microphones and a report of how it is working/sounding. If I do think that it is working without any derogation to the sound, I will then at that time ask for an independent Priuschat member to PM me a phone number where I can call them for a sound check. They can then post to Priuschat there opinions.

Part number 8625047020 is for cars with the production date between 8/03 and 11/05.
Part number 8625047040 is for cars with the production date of 11/05 or later.
I was told both are the same price.

[Skwyre7]

<div class='quotetop'>QUOTE(eagle33199 @ Oct 12 2006, 09:38 AM) [snapback]331644[/snapback]</div>

Since you say you speak loudly enough for the Mic, it may just be that when your wife is with you you'll want to switch microphones and speak up a little more yourself.
[/b]

Although I think adding a second mic would be neat to try, I would think that moving the mic to your wife's side would be the first step. It's also free, which is less than $70. It would give you a chance to see/hear if a mic on your wife's side would work. If it does, then you can save up your lunch money and try the second mic.

<div class='quotetop'>QUOTE(Cheap! @ Oct 12 2006, 10:49 AM) [snapback]331681[/snapback]</div>

This should take care of questions 2, 4 , and 5.

I just got off the phone with the dealer and I went ahead and ordered the part for $68.26/plus tax. BOHICA! It should be in on Wednesday. I will take pictures of the actual install with closer pictures of the duel microphones and a report of how it is working/sounding. If I do think that it is working without any derogation to the sound, I will then at that time ask for an independent Priuschat member to PM me a phone number where I can call them for a sound check. They can then post to Priuschat there opinions.

Part number 8625047020 is for cars with the production date between 8/03 and 11/05.
Part number 8625047040 is for cars with the production date of 11/05 or later.
I was told both are the same price.
[/b]

D'oh, a couple minutes too late on my last post. Good luck, Cheap!

[Cheap!]

<div class='quotetop'>QUOTE(Skwyre7 @ Oct 12 2006, 09:50 AM) [snapback]331682[/snapback]</div>

D'oh, a couple minutes too late on my last post. Good luck, Cheap!
[/b]

Skwyre7,
No, it is not too late to try. I can go switch the mic in the parking lot today at lunch. It shouldn’t take more then 10 min to do and I can call someone from the drivers seat. I will let you know how works out after lunch. Oh, wait, I forgot. Every once in a while I let her drive. I am not going to switch it back and fourth so I will still need two mics but for now I will make the switch just to try it out.

Thanks for the idea.

[Cheap!]

Coffee Break 10:15 to 10:30

Start
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Moved
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Done
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The call went well. My wife could not hear any difference with the microphone moved to the passenger side.

[eagle33199]

<div class='quotetop'>QUOTE(Cheap! @ Oct 12 2006, 11:02 AM) [snapback]331736[/snapback]</div>

The call went well. My wife could not hear any difference with the microphone moved to the passenger side.
[/b]

The big question is, however, will there be any difference with it's ability to hear her with it moved to that side? I would leave it as is, grab her when you get home, and call someone, see if it makes a difference.

[Cheap!]

<div class='quotetop'>QUOTE(eagle33199 @ Oct 12 2006, 11:18 AM) [snapback]331747[/snapback]</div>

The big question is, however, will there be any difference with it's ability to hear her with it moved to that side? I would leave it as is, grab her when you get home, and call someone, see if it makes a difference.
[/b]

That is the Plan...grab her when I get home. I can tell her it was recomended by Priuschat. Then we will call someone.

I'll Let you know how it goes. I only called her to make sure she could still hear me in the drivers seat and she could.