Technical Hidden Bluetooth Sound System Install [Non Invasive]

I wanted a new sound system for my 1957 Chevy but did not want to tamper with the original Factory AM radio. Unfortunately our city only has talkback AM stations . One stipulation was the car was not to be tampered with in any way! no holes drilled or knobs or visible systems underneath the dash etc . So to the untrained eye, they wouldn't know it even existed [and it must be able to be removed at a later date if needed]

My Husband did all the work for me, as I photographed it [but after his explanations and help, I would be comfortable doing this job myself]

We purchased a "Nobsound 10G pro" while in China , These are available on Ebay for $27 including shipping [or $38 with the power pack which you don't need to buy]

https://www.ebay.com/itm/Nobsound-NS-10G-PRO-Hi-Fi-DSP-Digital-Amplifiers-Stereo-Bluetooth-4-2-Power-Amp-/273395819252 The company is trustworthy [you will get the product you ordered]

This model was chosen over the lesser Nobsound NS-01G because it doesn't require or have a volume knob and has 100w output power. The Amp automatically defaults to "Bluetooth mode" unless a 3.5 jack is plugged into the Aux input and switches the input over to AUX input.[It uses a 3.5mm "Phone Jack" to switch over to Aux]

The Amp was so tiny which made us skeptical . So we used a 12v computer power pack and hooked up to our home theatre speakers. We paired my phone to it and tried it out.......................It was crazy, the sound it put out was unbelievable.

We tried an MP3 player via the AUX input and the sound was slightly better. It was now we discovered another hurdle, which was listening to FM Radio.

To listen to FM Radio from my phone was usually via Headphones ,and the 3.5 headphone wires doubled as an aerial. As soon as I plugged a headphone jack into the phone it switched off the Bluetooth transmitter [this was a phone issue, not the Amp]

So we needed to make the Amp AUX input accessible and hidden.

We also picked up a male power jack plug and some male bullet connectors which are perfect size for the speaker terminals from a local electronics parts store.

 

We wanted the Amp AUX input easy to plug the jack plug into without reaching under the dash or under the seat [while driving] , or the Amp mounted inside the glove box like an afterthought.

With the 1957 Chevy the glove box is central in the dash and the RH side is an empty space underneath. This space is ideal to mount the Amp flush up against the glove box liner and have a tiny hole punched into the cardboard for the AUX input.

The Amp has no method to mount it using this method, so we needed to make some brackets. We had some 19mm Aluminium angle which has cut into 2 pieces at 65mm.

The pieces were cleaned up with corners radiuses, then predrilled and pre-threaded for mounting screws.

Then we glued the pieces to the Amp [1 bracket on top and 1 on the bottom] , This needs to be done one side at a time, and 12 hours apart .A square was used to keep the face of the brackets level with the Amp face.

The glue we used was a Urethane which is very strong [Bostik , Simson ISR 70-03]

 

While the glue was curing , we decided to address the speaker issue [we didn't want to tamper with the existing Factory speaker in the centre of the dash. 1957 Chevy's had a rear speaker option, and the holes for the speaker are already in the rear parcel shelf from the factory, So we picked up a reproduction rear speaker grille.





Using a cardboard template, we marked out all the holes and cut out a piece of 20mm thick MDF [from an old kitchen shelf] This was needed to screw the grille downward through the original holes. and be capable of screwing upwards 2 x modern speakers which probably wont line up with the original holes.

A friend gave us some old 4" Clarion speakers to try out. These actually sounded OK for us non-Audiophiles but not as good as my home theatre speakers. So quality speakers will make a difference to the end results







more to come tomorrow ......

 

I used one of these: https://www.amazon.com/Kentiger-HY-...ywords=hy502s&qid=1561810458&s=gateway&sr=8-1 It has a built in FM radio and SD card and USB slots. With this unit, you would not need to connect your phone or MP3 player, though it does have blue tooth. It also has a remote so you can mount it just about anywhere.

 

Thanks for sharing.

 

Thanks for the write-up, pics and comments.

 

Nice job, so far. Looking forward to seeing the rest.


Sent from my iPad using The H.A.M.B. mobile app

 

way off traditional topic - but, if it helps preserve the original beauty of a classic and makes it more enjoyable to ride in why not take advantage of today's technology

 

We considered something this ^^^^^ but you need access to the control panel
We also looked at a modern stereo in a "drop down shelf" etc

With what we did , I can control the radio while it is playing from outside the car [eg: at a car show]
It has about a 14m [or yard] range.

A lot of people I've seen use a battery powered bluetooth speaker [about 5w] , this simply "Ups the game" to another level.

 

I completely understand this. [being a vintage car fan] but unfortunately this is 2019 and Radial tyres and electronic ignition are starting to creep in.
Ideally to be totally traditional we would have AM radio stations playing Marty Robbins and Buddy Holly [and I could leave the car as is ]

 

A trial fit of the speaker mount revealed a curvature in the rear parcel shelf, so out with the 5" grinder and a 40 grit flap disk and this was quickly corrected.[Photo 1]
When the grille and speaker mount were installed the flap disc was also used to take off about 2mm of the screws that were poking through. [Photo 2]

[Photo 3] shows the speaker wires poking through the hole where the rear seat panel tabs are folded. The speaker wires were routed along the R/H side of the car under the wiring covers and up the kick panel. This is normally the most difficult part of the whole job but my husband showed me a trick. He pushed curtain wire down behind the rear seat and inside the wiring covers and taped the speaker wires to it, and dragged the wires through . The seat squab needed to be lifted forward a bit for access.

[Photo 4] shows the rear seat with speaker grille finished

 

Now that the glue has cured on the Amp it is time to mount it to the glove box liner. Before this was removed, we needed to check to see if the glove box door stopper/arm didn't cause any interference issues.

The glove box door was closed, and the stopper was marked with a white marker.[Photo 1] Also the glove box roof angle was measured to get the Amp mounted level. A scriber was used to poke holes in the liner and it was screwed in place from inside the glove box. [Photo 2]

The Amp was removed, and a paper template was made using the holes to locate it. The template was needed to mark holes needed for the AUX input jack and the coloured Indicator light [both were 7mm holes] . Also a tiny rectangle hole was cut for the on/off switch .

[Photo 3] shows the blue indicator light on Bluetooth mode and this same light glows green on AUX input mode.

The glove box line was re-installed . The most difficult part of this whole project was re-aligning the glove box door to close properly

 

The speakers were easy to connect, crimped bullet connectors fit into the holes in the Amp Terminals nicely. And the male power jack plug was soldered to some dual core wire. As an extra precaution some hot glue was used to keep the wires from touching each other.

In most installs it could easily be finished now by simply connecting this wire to a 12v switched source and Ground. [photo 1]



But early Chevy's have a minor problem caused by the lack of accessory position on the ignition key. We both enjoy parking at the beach and listening to the radio [coffee / pizza etc]

The power source could have simply been hard wired to the 12v power source at the fuse box [interior light circuit] but all it would take is switching off the phone/MP3 and forgetting to switch off the Amp and the battery will slowly drain over the next 7 days .

In a box of old electrical components my husband had a 3 post diverter switch [ on / off / on ] normally the power source is the centre post and it can be switched either direction diverting the circuit.

[Photos 2 & 3] show this switch, and the simple dogleg bracket was shaped to fit inside the folded edge under the dash. There were some existing factory holes under the dash beside the handbrake lever.

This switch was reverse wired. The centre post goes to the Amp and the 2 outer posts come from the 2 different power sources [one is the normal key switched side of the fuse box, and the other from the 12v interior light circuit power source on the fuse box ]

So when we want to listen to the radio without the engine running ,a simple flick of the switch can save the points ignition burning out

[Photo 4] shows the 2 fuse box wires with male/female spade terminals . These go in between the Interior light and the factory radio terminals and can simply be restored later by unplugging.

 

Now the switch circuits need to be "idiot proofed" to prevent leaving the switch in the wrong position and draining the battery.

We had a Piezoelectric buzzer amongst all the electrical components. This was glued to the side of the switch [Photo 1] Glue was used because we didn't want to make a new bracket.

[Photo 2] Piezoelectric buzzers are a diode and only flow current one way, so the + side was spliced into the amp power side [switch output] and a 7.5A inline fuse was also used for the Amp [the factory fuses were 15A at the fuse box power sources]

The ground wire from the Piezoelectric buzzer went to the driver's door interior light switch.

[Photo 3] The tangs on a male spade terminal were filed down to fit into the factory Chevy door switch ,and a female spade terminal was spliced to this to re-connect the original factory door switch wire. [Photo 4] Again this can be simply unplugged and restored

This Piezoelectric buzzer only buzzes when the door is open AND the Amp is getting power. so if the key is OFF and the switch is in normal position it will be quiet. If the switch is left on in the 12v constant power position [interior light side] it will buzz when the door is open.

A side benefit is if you're listening to music normally while driving along and the door is opened it will buzz.

 

This photo shows the finished installation [The light flashes blue in Bluetooth standby mode, and when the amp picks up a Bluetooth signal the light glows a constant blue]

Apart from the small holes in the glove box liner , the whole system is non-invasive and can be simply unscrewed/ unplugged and removed

The system is totally hidden and uses a phone or MP3 player input for volume control so there is no external knobs. As stated earlier the Amp automatically is in "Bluetooth mode" unless a 3.5 jack is plugged into the Aux input.
I can control the volume and music choice from an Android phone while outside the vehicle [eg: cars shows]

The Amp was cheap, and the wires , switch, piezoelectric buzzer, and speakers were all free [We will probably upgrade to better speakers later]

We're very pleased with the end results [without being high end Audiophiles]

Thanks for reading........ Mimi

 

This photo shows when an MP3 player [or phone] is connected via AUX input [The same blue light will change to green when it picks up a signal from the AUX input]

The Aux input wire connects into the Headphone Jack on the MP3 player or phone.

So any sound device [including an old transistor radio] which is headphone capable can be used as a signal source.

 

WOW.......very impressive on many levels!! Thank you for documenting and posting all the photos and info.

I understand the ‘mechanics’ of this install......not sure I fully comprehend utilization of the electronic features, but my grandson probably does...

Ray

 

Wow, keep posting, this is the sort of how to information that makes our old traditional cars more user friendly.
Mike

 

Hi Ray,
Don't be frightened of electronics [in this example] ,it was a totally contained component. All it required to connect was pos+ and neg- [via a jack plug] and 4 x speaker wires for 2 speakers.

The actual skill was the imagination required for mounting it.[you could mount it vertically behind the dash in a roadster]

If you are "behind the play" [like myself] when it comes to electronics, you could still use an old "Sony Walkman" for the input source.[photo]
You substitute the plug in headphones for a Male to Male Aux input cable [supplied with the amp] this cable has 3.5mm headphone jacks at each end. This connects the Walkman to the Amp.

If the Aux input is not plugged in, the Amp automatically defaults to "Bluetooth". All android phones have this feature.
If you switch on bluetooth at the phone the Amp will pair to it, and the speaker in the phone switches off automatically when it plays music.

I used my niece as technical advisor [she loaded this "APP"? for me for a radio station that totally suits my car]
here: http://www.outpostradio.com/57chevyradio/ you can play this through a phone or PC.


When I want to download music , I save it to my PC then transfer it to my phone using the USB cable that comes with my phone [similar to saving file onto an external storage]

I managed to save a few old radio shows that were period correct for my car [ I even have 7 hours of some old "wolfman jack" shows, that were not available in NZ]

 

Mimi, Thank you for the reply. I just was getting comfy with the 20th Century when they sprung the 21st on me!

I think I grasp how the to connect to the amp and connect it’s output. It’s the variety of ‘sources’ that is a bit complex. I have satellite radio receivers in everything (newer than H.A.M.B. stuff) I drive, some integrated, a couple of portables. My interest would be learning if the Sirius/XM portable receiver could play through the amp with out going through an FM radio first. I am doubting that is likely, as the portable has to be sync’d to a specific FM frequency to play through the radio. I do have “an old Walkman”. Maybe a link from the portable Sirius/XM to the Walkman to the amp is feasible............

In any case (chauvinist alert), you are an unusual woman ......your husband is fortunate!

Regards to you both,
Ray

 

You should be able to get Sirius XM on a phone, and then play it via it's Bluetooth feature to a bluetooth speaker ,then no Aux input cable is needed.
[I see kids use bluetooth speakers all the time at our local beaches]
If your phone can play to a bluetooth speaker ,it can play to a bluetooth amplifier.
The only difference is the Bluetooth speaker needs it's own volume control.

My husband is lucky [I always remind him of this] but seriously, he is good with cars especially designing/understanding suspension and handling.
Plus he is a good teacher to his only student [I got thrown in the deep end with Road Racing Cars]

One question! what is the Buick in your Avatar.
Last weekend, we both went to check out buying a 49 Roadmaster convertible that is very famous.
The trouble was we don't know much about them.

 

For anyone with a smartphone there are services(?) Pandora being my favorite, that allow you the listen to practically anything you want at several monetary levels. From free to about $12 a month. You can Bluetooth your music to a set up like the OP or even a stand alone rechargeable speaker that you move from car to car or the beach your patio etc. Now get your kids or grandkids to explain the gobelygook I just typed.

 

^^^^^^^ my concern (lack of knowledge) is that using those apps for music will consume my data allowed on my phone contract. As for my phone itself, it is an iPhone, though I don’t think that makes any difference regarding most apps.

@Mimilan ...that is a 1950 Buick Roadmaster.......not mine unfortunately, though it could have been if I had the money and will to spend it. It belonged to a fellow near Chicago, IL, about 300 miles from my home, and was for sale about three years ago. It was such a striking automobile I co-opted the photo for my avatar.

I am a long time Buick fan and owner. The ‘49 Super and Roadmaster (Convertible and Sedanet) also are very high on my desirable list.......I did own a ‘49 Roadmaster 4 door about 40 years ago.....I’ve lived in apartments that were smaller than the inside of that car. Unfortunately it was destroyed, while parked, by a drunk driver.

My current Buick inventory consists of a ‘38 Special Coupe and an unusual ‘41 Buick Sport Coupe.....the latter awaiting TLC. Pic attached of my ‘38



Ray

 

I built a rather sophisticated and artsy Bluetooth system for my roadster. The only thing I do not like is using my phone for the source. If you want Pandora or any streaming service your phone will interrupt the tunes for calls and texts (ANNOYING). If you turn the phone to "airplane mode" you cant stream. My ipod is ancient and is not Bluetooth so I am now in the market for a new Bluetooth ipod with streaming capability. Of course it does work great just playing stored music on the iphone you just have to remember to turn the phone to airplane mode first.

 

When we take the Chevy out for a cruise [which isn't often enough] we switch one of our phones onto Airplane mode.

Then we play downloaded music from that phone.

My phone [Samsung J5 pro] has 32 Gigabytes of storage or 32,000 Megabytes . To put this into perspective, a downloaded 45 minute radio show is only 41.5 Megabytes. [so at that rate my phone has the capacity for 500+ hours of music]

Here's a real fun link for anybody interested in this thread [especially those who love nostalgia].

https://archive.org/details/Cruisin-AHistoryOfRockNRollRadio/TheCruisinYears.mp3

These are 40 to 45 [approx] minute Radio shows from each year 1955 to 1970, including the original old DJ's, Advertising ,and News etc

You can click onto the year at the top [and the little triangle] and play it on your computer .

If you scroll down a bit on the RH margin to "DOWNLOAD OPTIONS " and click on MP3 you can download and save to your computer all/any of these files. [ if you download all 18 files it is only 688mb ]

These files can simply be transferred to a phone or MP3 player [cheap "bluetooth" MP3 players are $30]

With these downloads you can cruise around listening to shows that really are "Traditional" [and surprise people at car shows]

@Hnstray @scotty t

 

Very interesting. I am going to look into this.

 

Nice job.
I did a Bluetooth install with a Kenwood 1824BT under the front seat with the remote control in the front ash tray, but if I were to do it today, I'd just buy a portable Bluetooth speaker. Those things can rock with up to 30 hours battery life.

 

My experience shows the music apps use very little data. I never listen to actual radio anymore all I use is the pandora app, in the house, garage or car. Sometimes 8 hours in a day, I’ve never used excessive data.

 

I just hide a bluetooth handsfree unit to play my music. The head unit fits most ashtrays and the amp sits behind the dash. In UK brands are Parrot or Bury but you should have similar.

 

A thief could easily walk off with a Bluetooth speaker, but would need to go looking for this system
And I also don't like things floating around loose in the car.

The other issue is most bluetooth speakers are only about 5w [A "Sharp GXBT7" is 20w but is also $160 on Amazon]
Ours cost $27 and is 100w. If we ever sell the car ,it would not be worth the effort to remove it. [I bought a spare amp because it was so cheap]

What we have basically done is "hard-wired" a bluetooth speaker so that uses the car battery and looks original [from outside appearances].

Anybody with a basic hotrod [like a T-Bucket or roadster] could hide the Amp underneath behind the dash and use a couple of speakers in the kick panels.
This is what building Hotrods and Restoring Cars is all about [Do it properly, and be proud of what You've done]