Correct loading for old car speakers?

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   Greetings,
I have an old pair of 1980s vintage Polk Audio Mobile Monitor III speakers that have been sitting in a shoebox for many years, and that still seem to be in reasonably good shape.

Now I'd like to use them as outdoor speakers in my back yard. In free air they sound rather bright. Just as a quick test, I stuck one speaker into a flower pot having more or less the correct diameter, and the bass response picked up a bit. Any thoughts as to how to figure out the recommended enclosure volume to provide the correct loading to get good response from these guys?

TIA

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YD Forums Members Profile Send Private Message Find Members Posts Add to Buddy List New Member Joined: 30 June 2022 Location: Israel Status: Offline Points: 8	Post Options Post Reply Quote YD Forums Report Post Thanks(0) Quote Reply Topic: Correct loading for old car speakers? Posted: 30 June 2022 at 5:19pm
	Greetings, I have an old pair of 1980s vintage Polk Audio Mobile Monitor III speakers that have been sitting in a shoebox for many years, and that still seem to be in reasonably good shape. Now I'd like to use them as outdoor speakers in my back yard. In free air they sound rather bright. Just as a quick test, I stuck one speaker into a flower pot having more or less the correct diameter, and the bass response picked up a bit. Any thoughts as to how to figure out the recommended enclosure volume to provide the correct loading to get good response from these guys? TIA

Line Array Members Profile Send Private Message Find Members Posts Add to Buddy List Registered User Joined: 19 March 2022 Location: New Jersey, USA Status: Offline Points: 83	Post Options Post Reply Quote Line Array Report Post Thanks(0) Quote Reply Posted: 01 July 2022 at 12:20am
	call Polk and see if they have a datasheet for your speaker that they can e-mail you ? Edited by Line Array - 01 July 2022 at 12:20am
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Conanski Members Profile Send Private Message Find Members Posts Add to Buddy List Old Croc Joined: 26 January 2006 Location: Ottawa, Canada Status: Offline Points: 2537	Post Options Post Reply Quote Conanski Report Post Thanks(0) Quote Reply Posted: 01 July 2022 at 3:09am
	They're desiged to go into the rear deck of a car with the trunk/boot acting as the enclosure, so they're esssentially an infinite baffle driver. So you can use a large sealed box or perhaps a transmission line or tapped horn, there are no "small" options unless you add a dedicated sub and use them as mid/hi components.

Line Array Members Profile Send Private Message Find Members Posts Add to Buddy List Registered User Joined: 19 March 2022 Location: New Jersey, USA Status: Offline Points: 83	Post Options Post Reply Quote Line Array Report Post Thanks(0) Quote Reply Posted: 01 July 2022 at 6:22am
	one option would be to do a vented box but stuff the vent with something like polyfill so that it's partially leaky - that will make the box act more like an open baffle. i'm thinking that even if the speakers were designed to go into doors the doors aren't as rigid as a speaker cabinet. the OP will probably want a fairly large box that is also somewhat "leaky" acoustically ( via a stuffed vent or flex in the box itself ).
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YD Forums Members Profile Send Private Message Find Members Posts Add to Buddy List New Member Joined: 30 June 2022 Location: Israel Status: Offline Points: 8	Post Options Post Reply Quote YD Forums Report Post Thanks(1) Quote Reply Posted: 01 July 2022 at 10:10am
	Tried Polk before posting here. Their reply: Please note that we no longer hold any documentation on our database for these legacy speakers. I was a bit surprised and disappointed by that and I suspect they may still have data somewhere for their old models, but that it would be inconvenient to find.