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Sound Reinforcement - Forums for Live Sound Professionals - Your Displayed Name Must Be Your Real Full Name To Post In The Live Sound Forums => Installed Sound/Contracting => Topic started by: Joseph D. Macry on March 09, 2016, 03:29:37 pm

Title: Bluetooth thru steel rack door?
Post by: Joseph D. Macry on March 09, 2016, 03:29:37 pm
I occasionally supply a Bluetooth-enabled CD player (Tascam CD-200BT) in a rack.
I've always tried to spec a plexiglas door to allow good reception at the front of the unit.

But now a school says they want solid steel door on the new Gymnasium rack because flying basketballs might break the Plexiglas. (Not worried about athletes hitting the rack, as it's tucked in beside the bleachers.)

Do you think the Tascam would receive the Bluetooth signal from Coach's iPhone if the rack is closed with steel door? Coach could be anywhere about the Gym, which is sized for a single basketball court.

I noticed that Denon DN-300Z CD/BT/AM/FM deck has a remote Bluetooth antenna. Never played with that model.
Title: Re: Bluetooth thru steel rack door?
Post by: Rob Spence on March 09, 2016, 04:14:50 pm
I occasionally supply a Bluetooth-enabled CD player (Tascam CD-200BT) in a rack.
I've always tried to spec a plexiglas door to allow good reception at the front of the unit.

But now a school says they want solid steel door on the new Gymnasium rack because flying basketballs might break the Plexiglas. (Not worried about athletes hitting the rack, as it's tucked in beside the bleachers.)

Do you think the Tascam would receive the Bluetooth signal from Coach's iPhone if the rack is closed with steel door? Coach could be anywhere about the Gym, which is sized for a single basketball court.

I noticed that Denon DN-300Z CD/BT/AM/FM deck has a remote Bluetooth antenna. Never played with that model.

In general, putting a radio behind a steel door is a bad idea. Bluetooth isn't exactly a high power radio in the first place. It is designed for short distances.
I wouldn't do it if it were me.


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Title: Re: Bluetooth thru steel rack door?
Post by: Cailen Waddell on March 09, 2016, 05:19:39 pm
I have put cd-200bt into dance studios in steel racks with steel doors.  Your lucky to get 30'.  Lucky for me it was an existing rack and we were planning to remove the door anyway.


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Title: Re: Bluetooth thru steel rack door?
Post by: Stephen Swaffer on March 09, 2016, 05:34:54 pm
Maybe use an impact resistant lexan?  There are tougher plastics than plexiglass that would be more RF friendly than steel?
Title: Re: Bluetooth thru steel rack door?
Post by: Lee Douglas on March 09, 2016, 06:01:00 pm
I've used something like this to remotely locate a Bluetooth receiver through conduit to a metal box in a more centralized location away from the main installation rack.  While it worked fine, you would still be pressed to get more than 30' out of it, per standard Bluetooth spec.  Maybe a lockable compartment near the rack that the coach could place his phone in.  Of course if they're looking for transport control as well...

http://www.amazon.com/Signa-ST-WBT1-In-wall-Bluetooth-Receiver/dp/B00OY8CWDC
Title: Re: Bluetooth thru steel rack door?
Post by: Scott Carneval on March 10, 2016, 11:18:59 pm
Have you thought about using an Apple Airport Express and sending audio from the Coach's phone via Airplay?

What about a perforated steel door? It would probably provide better reception than solid steel.
Title: Re: Bluetooth thru steel rack door?
Post by: Lee Buckalew on March 11, 2016, 08:39:37 am
What about a perforated steel door? It would probably provide better reception than solid steel.

2.4GHz wavelength is approx 4.92 inches.
Unless the perforations are significantly larger than approximately 0.49" in diameter then the door may be solid (Faraday cage) to the RF wavelength for Bluetooth (this is the same frequency at which microwave ovens generate their frequencies for cooking, think about the perforated door), however, much of this is dependent on the metal itself, any non-sealed paths that are present, etc., etc.,

It may be worth a test if that is possible.

Lee
Title: Re: Bluetooth thru steel rack door?
Post by: david albert on March 11, 2016, 12:21:44 pm
Take a look at a microwave door, usually perforated, and no microwaves come out!  Microwaves ovens operate at 2.4Ghz too!

2.4GHz wavelength is approx 4.92 inches.
Unless the perforations are significantly larger than approximately 0.49" in diameter then the door may be solid (Faraday cage) to the RF wavelength for Bluetooth (this is the same frequency at which microwave ovens generate their frequencies for cooking, think about the perforated door), however, much of this is dependent on the metal itself, any non-sealed paths that are present, etc., etc.,

It may be worth a test if that is possible.

Lee
Title: Re: Bluetooth thru steel rack door?
Post by: Lee Buckalew on March 11, 2016, 02:16:53 pm
Take a look at a microwave door, usually perforated, and no microwaves come out!  Microwaves ovens operate at 2.4Ghz too!

That's exactly what I said.  Unless the perforations are GREATER than 0.49" in diameter the perforated door will be solid to the 2.4GHz frequency.  However there are some other factors at play such as how well sealed other pathways are, etc.

Lee
Title: Re: Bluetooth thru steel rack door?
Post by: Joseph D. Macry on March 11, 2016, 09:07:11 pm
Maybe use an impact resistant lexan?  There are tougher plastics than plexiglass that would be more RF friendly than steel?

It's whatever Middle Atlantic puts in the product. I don't manufacture the racks myself, just assemble and install.
Title: Re: Bluetooth thru steel rack door?
Post by: Joseph D. Macry on March 11, 2016, 09:09:55 pm
Have you thought about using an Apple Airport Express and sending audio from the Coach's phone via Airplay?

What about a perforated steel door? It would probably provide better reception than solid steel.

No. Bluetooth enabled CD player is in the specs.
Title: Re: Bluetooth thru steel rack door?
Post by: Lee Douglas on March 11, 2016, 09:32:52 pm
No. Bluetooth enabled CD player is in the specs.

Do they also spec the desired performance of the Bluetooth in that player?   It sounds like what they want and what they've spec'd are two different things.  Go with the spec and change order it later.
Title: Re: Bluetooth thru steel rack door?
Post by: Hal Bissinger/COMSYSTEC on March 12, 2016, 04:59:51 pm
Quote
Do they also spec the desired performance of the Bluetooth in that player?   It sounds like what they want and what they've spec'd are two different things.

I wouldn't put too much faith in the technical abilities of anybody who would "tuck the rack beside the gym bleachers" then be concerned about it being damaged to begin with.

-Hal

Title: Re: Bluetooth thru steel rack door?
Post by: Jason Lavoie on March 13, 2016, 11:13:33 pm
I occasionally supply a Bluetooth-enabled CD player (Tascam CD-200BT) in a rack.
I've always tried to spec a plexiglas door to allow good reception at the front of the unit.

But now a school says they want solid steel door on the new Gymnasium rack because flying basketballs might break the Plexiglas. (Not worried about athletes hitting the rack, as it's tucked in beside the bleachers.)

Do you think the Tascam would receive the Bluetooth signal from Coach's iPhone if the rack is closed with steel door? Coach could be anywhere about the Gym, which is sized for a single basketball court.

I noticed that Denon DN-300Z CD/BT/AM/FM deck has a remote Bluetooth antenna. Never played with that model.

The 300Z is great.
The antenna is removable, but not 'remote' by default, however it is removable so you'd have to find an extension cable for it.
That should take care of your problem though

Jason