Author Topic: Advent/3 and astro sonic doesn't mix...?  (Read 1554 times)

kyuubethe3rd

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Advent/3 and astro sonic doesn't mix...?
« on: August 07, 2015, 09:01:39 PM »
(not sure if this is right forum)

So I just finished my astro sonic and everything sounds great, so I got these small Advent/3's from my Dad as celebration along with some records.

So I hooked these up to my astro sonic and while they sound great, they're quieter than the internal speakers. Is there a reason why they sound quieter? I heard these are inefficient and they require more power and if that is the case and the astro sonic isn't strong enough to handle these speakers, is there an inbetween amp that exists that I can put between the output of the astro sonic and the speakers that'll boost the signal to make these speakers sound equally loud? Or is there a connection that I forgot to reconnect?

AlexanderMartin

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Re: Advent/3 and astro sonic doesn't mix...?
« Reply #1 on: August 07, 2015, 09:42:14 PM »
Small Advents are not very efficient at all, surprised the astro could even drive them. Get some efficient speakers like Altecs, Jensen's, or Electrovoice.

Alan Maier

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Re: Advent/3 and astro sonic doesn't mix...?
« Reply #2 on: August 07, 2015, 10:10:12 PM »
What you are having happen is quite common when adding speakers to a Magnavox console stereo. The reason is due to speaker sensitivity, or how loud the speaker will play when driven by a given amount of audio power.


When Magnavox designed these stereos, they did so as a system where the amplifier power, speaker power handling and speaker sensitivity were all calculated to work in harmony. Speakers used were very, very efficient which is to say they played extremely loud for the signal they were supplied. To play a Magnavox console at the 1 watt level is to have to shout over the music in all but the largest rooms. The speakers were that efficient.


Now come over to the Advent/3 speakers. Advents from the original Henry loss era were not very efficient overall (common of that era for air suspension designs) - the opposite of what Magnavox was installing in their consoles. To make things worse in your case, the wonderful sounding Advent/3 was by far the least efficient speaker Advent ever offered. They sacrificed efficiency for that unusually extended bass from a small woofer. So now you are dealing with complete opposites, internal speakers that are incredibly efficient and an external pair of speakers that were known for their low efficiency. In specification terms, the Advent/3 rated sensitivity (taken from memory) was down in the low 80 db/w/m range while the internal speakers of the console exceed 100 db/w/m.


There isn't a practical way of having them play equally loud at the same time. The console can handle them to respectable levels - but switch to the internal speakers and you'll be blasted out of the room. This is just one of those extreme mis-matches that may not work well unless you live with the Advents only for their smooth sound and switch to the Magnavox for when you want to play 1960's jazz and popular music of that era that the internal speakers were voiced to perform so well at.

kyuubethe3rd

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Re: Advent/3 and astro sonic doesn't mix...?
« Reply #3 on: August 08, 2015, 01:26:04 AM »
Well, at least these speakers were free. :(

So there's really nothing I can do at all? Not even a device that can boost the signal between the console and the speakers? Hate to see these fall by the wayside. Ah well.

Alan Maier

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Re: Advent/3 and astro sonic doesn't mix...?
« Reply #4 on: August 08, 2015, 08:42:55 AM »
Unfortunately there isn't a product made that would fix this difference right. An additional amplifier could be connected to the tape output, however you would use the volume control on the add-on amplifier and it really would not be cost effective. You would basically be making for a second stereo.


Back in the day, Magnavox also had a full line of speakers (and receivers) that were basically based on console components. The speakers were as efficient as the console speakers and were a perfect option for extension speakers. They were also voiced the same or similar, so you had that Magnavox sound in a second room. Today most speakers on the market are much more efficient than the east coast speakers of the 1970's, so a typical pair of Polks, or dare I say it - Bose 301's for example, would play closer to the console volume level.


A better vintage match would be older JBL, Klipsch or the wood grill fitted Sansui, Pioneer and Kenwood models from the era. You have a really pleasing sounding pair of speakers, they simply happen to be extremely inefficient and were known for that back in their day. They were background music speakers for the bedroom or den that offered full size speaker fidelity in a compact size. Even Advent's own Model 300 receiver could not drive them loudly.

darrenwgaransi

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Re: Advent/3 and astro sonic doesn't mix...?
« Reply #5 on: March 08, 2016, 07:05:33 PM »
Actually, there is something you can do. Connect a wire wound resistor in series with each set of internal speakers until their output is brought down to that of the external speakers and then raise to volume to wherever you want it to be. This will also help keep the total impedance of the circuit at a safer level when all 4 speakers are working at the same time. Experiment with a range of 4-10 ohms.