Magnavox astro sonic twitter speaker replacement

Electrically amplified phonographs or radio/phonographs and related components (approx. 1928-1990).



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spierce10
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Magnavox astro sonic twitter speaker replacement

by spierce10 » Wed May 22, 2013 4:16 am

I have a Magnavox 20RP628 astro sonic and have had it serviced to replace the capacitors. Once the chassis was put back in, the guy determined that the tweeter speakers weren't working, which is why I kept hearing such a 'bass-y' sound. He said that the 4 x 10.5 twitters needed replacing. I've removed the old speakers and wanted to know if I can buy 'new' tweeter speakers such as the Nippon NTX417. I can't tell if they have the 2 simple connectors that the Magnavox 580088-1 tweeter speakers have?

Any advice appreciated!


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Re: Magnavox astro sonic twitter speaker replacement

by Ron Rich » Wed May 22, 2013 4:36 am

Have you actually stuck your ear next to the speaker ? It would be highly unusual, IMHO, that they both are "bad". The type of "connectors" used is the last thing I would worry about when selecting speakers--
Ron Rich


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Re: Magnavox astro sonic twitter speaker replacement

by spierce10 » Wed May 22, 2013 4:42 am

Yes, and I thought is was odd that both don't work. The technician said he hadn't seen it either, but said I should replace them to see if that works. Everything else is in such good shape and he couldn't find anything wrong with the wires leading to the driver/tweeter.


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Re: Magnavox astro sonic twitter speaker replacement

by Ron Rich » Wed May 22, 2013 4:48 am

I dis-agree with your " technician"--A speaker check can be done in less then two seconds, with a very basic meter--I do believe, I'd find another "tech"--Ron Rich


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spierce10
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Re: Magnavox astro sonic twitter speaker replacement

by spierce10 » Wed May 22, 2013 4:57 am

He even said that his meter didn't show a problem, but he didn't know why the tweeters weren't working. Good luck on finding somebody else in Atlanta! I'll call the guy tomorrow and see if he can take another look based on what you're saying.

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MattTech
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Re: Magnavox astro sonic twitter speaker replacement

by MattTech » Wed May 22, 2013 8:48 am

I have seen older Magnavox horn tweeters go bad, on occasion.
An ohm meter across the terminals or a "D" battery across the terminals would determine if this is the case.
The battery would cause a "click" in the horn.
But check the crossover capacitors, being aged, they could also be open/defective and need replacing. (if the tweeters check good, of course)

As far as original replacements, that would be a needle in a haystack issue.
Just about any decent tweeter, even cone style, would work fine.
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Re: Magnavox astro sonic twitter speaker replacement

by spierce10 » Wed May 22, 2013 6:13 pm

Thanks Matt! I checked them again and I can actually hear sound coming from the tweeter. Not sure why the guy said he couldn't hear anything. But he did say that his meter checked them out fine. The sound is just very quiet which is why the overall sound is more bass. I've turned the treble knob to the max and the bass knob to the min.
The guy replaced 20 capacitors on the chassis - is that the only place the capacitors are located?
I checked the connectors and I don't see any obvious damage. I may order one new tweeter to see if I notice any difference - do the new ones have those same two connectors? I can't tell from any of the photos online. I may just take a chance!


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Re: Magnavox astro sonic twitter speaker replacement

by Ron Rich » Wed May 22, 2013 9:32 pm

FYI--I know nothing about this particular machine--but, "changing 20 caps" does not necessarily constitute a sound system repair. Other things also need checking, and possibly changing. That being said, if you hear sound from those tweeters (BTW--NOT "twitters"), chances are they are still OK. As Matt asked--did you (or your "tech") check the crossover cap(s) ? They are not generally located inside an amp, but usually closer to the tweeter. As I stated earlier--speaker connectors are the least of your worries, as they can be changed, if needed, or the wires can be soldered to the speakers.
Ron Rich


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Re: Magnavox astro sonic twitter speaker replacement

by spierce10 » Thu May 23, 2013 12:24 am

Thanks Ron! I have left a message with the 'guy' about the crossover caps. I know he didn't do anything like that, so I hope to address it with him.


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Re: Magnavox astro sonic twitter speaker replacement

by Thom » Thu May 23, 2013 1:35 am

He may have replaced some old caps using new ones with the wrong spec within the audio circuit causing muted highs. Perhaps a resistor or two is out of spec but I agree with Matt and Ron concerning the crossover network.
If you had a spare speaker you could simply connect it to the tweeter wires to test for volume or temporarily bypass the crossover with the tweeters in question.
Vinyl is disease which attacks that area of the brain desiring digital recordings. Once you catch it, you are cured.

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Re: Magnavox astro sonic twitter speaker replacement

by MattTech » Thu May 23, 2013 1:57 am

Please note that people, as they age, cannot hear the highs as much from these things, and think they sound boomy/muddy.
In fact, they were designed to sound deep and boomy to "impress" with their bass response.
Now, as to young people today, they would also sound muddy, in comparison to growing up listening to tinny little boxes that supply cheap earbuds with music.
The young under-30 crowd doesn't understand analog high fidelity as it once was.
The Internet is a marvelous thing, however it's not a good substitute for actually being there.


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Re: Magnavox astro sonic twitter speaker replacement

by Bobby Basham » Sat May 25, 2013 8:18 pm

I don't know what all the "twitter" is about, but the crossover network is mounted on its own little circuit board located elsewhere inside the cabinet, in most cases (at least with the eight Astro-Sonics that I have) mounted on the side of the record storage compartment when you remove the back. That would be over on the left side, opposite from the turntable near the left channel woofer/tweeter. Also check the wiring diagram usually pasted somewhere inside the cabinet, many times on the base/floor. --BB

Bobby Basham
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spierce10
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Re: Magnavox astro sonic twitter speaker replacement

by spierce10 » Wed May 29, 2013 4:12 am

I talked to my guy and he clarified that he checked the caps and they seem fine. His meter showed everything was fine as well. He thinks that replacing the tweeters with new ones would give me more sound. So I ordered Nippon 417 horns and the sound was better, but the driver is slightly too big to allow the horn to fit. The driver bumps into the woofer back.

Any idea of where I can find tweeters that will fit back in that space?

Thanks!


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Re: Magnavox astro sonic twitter speaker replacement

by Bobby Basham » Wed May 29, 2013 8:41 am

Somewhere in my reading of different newsgroups over the last 17+ years, someone stated that those horns are midrange, not tweeters. I did order some 4x10 Pyle tweeter drivers from Parts Express as replacements. They will make your ears bleed! I then ordered some midrange, they were still on the bright side, loud, about 106 decibels, but were manageable if you had a chassis with a Timber control.

I can only speak for myself, but have had problems replacing problem speakers in my consoles. Back in the good ole' days, you could go to Radio Shack, Olsons (in Ohio) for replacement speakers. I refuse to use Craigs List and Ebay to buy old speakers. They could fail a week after you receive them.

I was getting ready to give a beautiful Maytag washer to my coworker/cop friend, and it died a week before I was going to deliver it to him.

Not doing enough researching, I've had to resort to stiff-coned PA/guitar speakers because of the amp's damping factor, and horns are all over the map. These were used on spare units for experimental purposes. There has to be some speaker equivalents out there, even more efficient. --BB

Bobby Basham
Tucson, Arizona


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spierce10
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Re: Magnavox astro sonic twitter speaker replacement

by spierce10 » Thu May 30, 2013 4:55 am

I've searched online and can't find any 4 x 10.5 horn speakers with a smaller driver/magnet on the end which will fin in my Magnavox astro sonic (1966 best guess). I'm still trying to figure out why the sound is still a bit 'muffled' sounding even with the bass knob turned all the way down and the treble knob turned all the way up. Is it possible that the woofers need replacing? When I put my ear up to the side of he console and listen to those speakers, they don't sound crisp. There's not any distortion or crackling per se, just not clear and crisp like I would expect. I can turn the volume up very high and the sound is 'good' but you just know that something is missing. I wouldn't expect it to sound like a high end stereo system, but I just don't feel like this sound is where it should be. As mentioned, the tech rep said he checked the caps and they are fine. Thoughts????

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