Audio Systems/Yamaha AVX-500 amp


Have been using this old gear since 1990. Has the Yamaha active servo speakers, one of which needs repairs to the bass speaker- cost $50.

I have 2 questions.

1. is this system worth fixing?

2. Is this amp suitable for driving modern speakers?

Thanks for response.

ANSWER: Hi, Fred. Sorry this took so long. I am currently in a very remote location.

If you mean that the speaker repair has been bid at 50$, the short answers are yes and yes.
This is especially true if you were satisfied with the sound of the system when it all worked properly.
The amplifier is rated at 80 watts x2 plus 15 watts each for the two rear channels and the center channel. Impedance loads should be from 6 to 8 Ohms per channel so the amp should work fine driving most modern speakers.
If you need any further advice, do not hesitate to ask.
BTW, here is a link I found about the amplifier with a service manual download link.


---------- FOLLOW-UP ----------

QUESTION: You say above that this amp is rated for 15 watts each for rear and center channels.

As a practical matter what type of speakers will work with this wattage?

Most speakers I see are rated for much higher watts.

It's obvious I'm no audiophile.

Thanks for any help.

I understand your concern and admittedly I was speaking of more efficient, modern designs like Polk, Klipsh and Cerwin-Vega to name a few.
I will not argue that most modern speakers are not as efficient but there are enough efficient designs out there to service most budgets that are aware of what they offer.
In a nutshell:
I only use RMS (continuous average) ratings when choosing components so I also pay close attention to how much SPL a speaker puts out with 1 watt applied. This is usually stated as decibels per watt (eg.. 90Db@1watt ).
Without getting too deep...
When you double the power going to a speaker, its' output in decibels goes up by 3Db. So if you apply 15 watts to a center channel that has an efficiency rating of 84Db/1watt, the output goes from
84@ 1 watt to
87 @ 2
90 @ 4
93 @ 8
Up close to 96Db@15 watts (or a 12Db gain).
96 @ 30
99 @ 60
102 @ 120 watts... and so forth.

That said, if you instead chose a speaker rated at 95Db@1 watt,
The same 15 watts would give you 107Db!
Here's is such a center channel

You can see that the 84db speaker will not get as loud even with 250w applied to it.
Bottom line, max or peak power ratings are useless and the efficiency rating of your speakers is very key.

Of course, if you are considering the rear pair, you can add about 6Db more for them due to having twice the amount of speakers.

I hope this helps explain things more fully and I am sorry if I was inarticulate in that first response. When I said 'most' I was referring to the main two channels.


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Jerry Mael


My forte is audio.. Car/Home/Boat. You name it, I will help you even if it is just a link to more assistance. If you want to interface new gear to your factory radio I can do us both a favor and tell you to go to or call them at 1.800.555.7088. They really are top notch at doing that for people with great support. I will re-direct most questions of that nature to them. The rest of it... I am eager to help you with. I am also not a 'Master Installation Technician' that will tell you I cannot assist you with cars not made in the USA. Talk to me about any audio upgrades including 'bang for the buck'.
Specialties include: Overall Acoustics, Gain structure/settings and Enclosure design, system design/consultation, when/where to get which upgrades as well as other pertinent info for the mobile audio enthusiast and much more.
I also am NOT interested in buying your used gear so do not waste our time asking me.


My specialty as it is offered here, is Mobile and Home Audio Consultation.
Eight years IASCA - Pro 251-500 watt class
With Allexperts since 1999 (on and off).
35 years of overall professional sound and acoustical/electronic experience (since 1977) including: Sound Offs, Home audio, Mobile audio, Live sound, Churches, Theater, Live DJ and Studio Recording (analog and digital software and hardware), Effects, Looping, analog/digital mutli-track and mixdown . My mother was a record producer so I picked up a lot of additional professional knowledge and experience through the years. I was a Drum Tech for the Banshee reunion tour and toured as sound man with a regional act called Champion so I have practical knowledge for many aspects of audio.

If I cannot directly answer your question I will use my vast resource network to help you get a usable answer.

Favorite Mobile components:
Any amplifier based on ZED principles. Examples are Diamond, Zapco, Hifonics, Autotek, ect. And of course, Nakamichi (yes, still in business)
McCaulley, Polk and Dynaudio Speakers.
Clarion/Nakamichi headunits and processors.

>35 years of real world, audio experience.

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