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Author Topic: best mobile speaker for a noisy environment  (Read 3251 times)
KB2HUK
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« on: December 18, 2010, 11:02:15 PM »

Hi Gang , I need a mobile speaker for a noisy truck .  Who can recommend a very good mobile speaker . I am looking for a quality loud articulate speaker dsp would be a plus .  I imagine I would be placing it approx 5 feet away from me .  thanks for your opinions . John kb2huk
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K1CJS
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« Reply #1 on: December 19, 2010, 06:14:09 AM »

There was another thread like this a couple of years ago.  Many different opinions were offered.  Myself, I prefer the speaker units that were offered with Motorola and/or GE radios systems for public service and commercial uses.  They're hard to beat--and you can get then on e-bay or at hamfests for under ten bucks apiece.  Those units were designed for just the purpose you describe.  It's hard to imagine anything more noisy than a fast moving police car--revving engine and siren going--and the officers inside HAD TO be able to understand the comms coming into their unit.
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KE7EJG
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« Reply #2 on: December 19, 2010, 06:48:04 AM »

I have successfully operated mobile for several years using an old Motorola communications speaker AND a Gap hear-it in line audio DSP unit.  The Gap module is actually made by BHI in England.  I have tried several DSP filters and have kept this one in the car due to it deep DSP noise filter.  I use it on SSB with the the pre-amp and rf gain fully on.  Only usable for slow speed CW - the FIR filter takes a second or so to "recover".  Also, I use it on 2m FM with the squelch fully open.  No squlech needed.  The Hear-it module has flakey connectors (1/8 in stereo and RCA are both provided).  Otherwise I have had great success.  Timewave & MFJ products have much less noise reduction but good bandwidth filters.  SGC is great for faster CW, it recovers quickly but only has a few selections for bandwidth and depth of noise reduction.  FYI, I run run the IC-706 original rev and magmount antennas to NMO connections on the SUV roof.  NMO grounds the roof, works well.  10m, 40m and 2m work well for me.  I am in the Phoenix area, very noisy.  Good luck - Alton, W7ACX
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K0BG
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« Reply #3 on: December 19, 2010, 08:09:05 AM »

Both the GE and Motorola are good choices as mentioned, but here's a suggestion. Mount the speaker under the seat pointing up. This helps cut a lot of the high frequency hash we all have to deal with.

I aso agree that some add-on audio DSPs do a decent job, but none are as good as an IF-based DSP. Even then, some high frequency hash sneaks through. To me, it is this hash which is the most tiring. One of the best solutions I've come up with is the SCAF-1 from Idiom Press. It is not a cure-all by any means, but during really noisy conditions, it makes reception possible. 
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WB6BYU
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« Reply #4 on: December 19, 2010, 08:16:32 AM »

In one of our Search and Rescue trucks we installed a stereo headliner wired so that each occupant
had the VHF radio in one ear and the UHF radio in the other.  That made it easy to hear (because
the speakers were close to your ears), but didn't get in the way.  It also made it easier to tell which
radio was active.

In my last 3 vehicles I've mounted the speaker on the back of the headrest - sometimes actually
between the top of the seat and the headrest.  This is very easy to hear, but out of the way and no
danger of impact in an accident.

A good quality speaker (such as the Motorola or GE units) helps, certainly, but proximity to your
head makes a huge difference in the ability to hear clearly in an noisy environment.
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W9PMZ
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« Reply #5 on: December 19, 2010, 08:49:36 AM »

"Mount the speaker under the seat pointing up. This helps cut a lot of the high frequency hash we all have to deal with. "

Have never tried this.  What physical size and power rating do you think works best?

73,

Carl - W9PMZ

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K0BG
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« Reply #6 on: December 19, 2010, 12:01:36 PM »

In my installation, I use an Icom IC-7000, and the speaker is plugged into the remote head. With the switch set to speaker, the audio level is about 1 watt. Albeit my Ridgeline is rather quiet, the audio power has proved adequate.

To each his own, but I don't mount speakers in the uprights of head rests, as I personally believe it is an unsafe practice.
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KI4SDY
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« Reply #7 on: December 19, 2010, 08:22:27 PM »

The Motorola and GE speaker suggestions are good if you can find them. If you can't, another good inexpensive alternative is the 20 watt Bearcat external speaker for $12.00 from Walmart with an online order. You can run it to full volume without distortion, if you can stand to stay in the vehicle. Remember, 1 watt is normal listening volume and with the windows up it is probably too much. Why do I say that? Because speaker placement is crucial to intelligibility. Also, the closer the speaker is to your head the less volume you need, which is easier on your ears and prevents hearing damage. Mount the speaker as close to you as possible in a safe location, taking collisions into account.   Smiley

I also found some good small rectangular black 20 watt speakers with mounting brackets and 1/8" plugs made by Idec called "Micro Smart" on eBay. I have been using them on many of my radios and although they are made for stereo use they work great for voice and allow you to get them very close to your head in a vehicle. I have bought them as low as $1.99 each in groups of 2 to 8 speakers. Buy a bunch for the price. You will be glad you did!  Cheesy

Since space is limited in the the lady ham's mustang, we mounted an Idec speaker on her passenger side visor with two black flex ties close to her right ear. The sound is so dynamic and life-like in that location, it startles her every time a ham on the local 2 meter repeater gives a call. The small size of the speaker is unobtrusive and looks very professionally installed that way. Shocked

I am glad most of the speaker suggestions are of the good and cheap variety. They are my favorite!  Grin

By the way, police car engines don't rev because they all have automatic transmissions, so even at high speed they are relatively quiet. Unfortunately, the 250 watt sirens are loud and they have to turn up the volume during an emergency response or a chase. Just the voice of experience speaking.  Wink  
« Last Edit: December 28, 2010, 07:14:52 AM by Guy "Vern" Wells » Logged
KG6MXV
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« Reply #8 on: December 22, 2010, 11:29:00 AM »

Those are all great suggestions.  I guess I"m cheap. Shocked I bought the small MFJ 4" black speaker for cheap at Pacificon some years ago and have used it since with great success in a Honda Civic (noisy at highway speed) and and now in a Toyota Camry (not so noisy).

I remember the bigger speakers mentioned above from being in police work years ago, and I second the idea that when you're rolling with lights and electronic siren above the roof line, its kinda hard to hear anything.

If you're cheap like me, don't hesitate to try the MFJ speaker.
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