Newbie Woofer Replacement (need advice)

[ragnarok775]

Hi, I recently started dabbling in setting up my own little speaker system since i got this free amplifier. I have had these OLD Infinity Refrence-EL (2-way bookshelf speakers) speakers lying around for quite some time and decided to hook them up to the amp and see how they sound.

The highs sound great, better than any speaker ive ever owned before (doesnt say much) but when i get in the < 100Hz range the woofers make an awful vibrating sound. I take the covers off the front to find that the foam rings around the woofers are non-existent. I looked into a self-repair kit for these woofers but the price for most of these kits are about 30$ and with that I could just about get 2 brand new 5.25" woofers.

My question is (sorry about the long intro) if i were to replace these "woofers" what exactly should i be looking for? A mid-range 5.25"? An actual Woofer? and given that the current Impedence throughout the entire loudspeaker is 6ohms should I go for a 4ohm or 8ohm replacement?

Thanks for any assistance.

PS. All of my bass isnt going to be from these Refrence-EL's. I have an 6" ported-sub from an old Home Theater system that my friend was going to throw away .

 

[Swerd]

Hi, I recently started dabbling in setting up my own little speaker system since i got this free amplifier. I have had these OLD Infinity Refrence-EL (2-way bookshelf speakers) speakers lying around for quite some time and decided to hook them up to the amp and see how they sound.

The highs sound great, better than any speaker ive ever owned before (doesnt say much) but when i get in the < 100Hz range the woofers make an awful vibrating sound. I take the covers off the front to find that the foam rings around the woofers are non-existent. I looked into a self-repair kit for these woofers but the price for most of these kits are about 30$ and with that I could just about get 2 brand new 5.25" woofers.

My question is (sorry about the long intro) if i were to replace these "woofers" what exactly should i be looking for? A mid-range 5.25"? An actual Woofer? and given that the current Impedence throughout the entire loudspeaker is 6ohms should I go for a 4ohm or 8ohm replacement?

Thanks for any assistance.

PS. All of my bass isnt going to be from these Refrence-EL's. I have an 6" ported-sub from an old Home Theater system that my friend was going to throw away .

If you want to use those Infinity speakers, pay the $30 and repair the foam surrounds that have rotted away, or find exact replacements for the original Infinity woofers, which will probably cost you more.

To install new woofers in those cabinets, you need to know more than whether they fit into the existing holes. Woofers have different electrical and mechanical performance parameters that must be known or measured before designing a speaker cabinet. These parameters are called the Thiele/Small (T/S) parameters, named after the two men who described them and first worked out the math equations to use in designing speaker cabinets. To design a standard sealed or ported cabinet, you must know at least 3 T/S parameters for a woofer, Vas, Qts, and Fs.

Those Infinity cabinets were designed around the T/S parameters of those original woofers. If you replace the woofers and use the old cabinets, the new woofers must have similar or identical T/S parameters to the original woofers. If you ignore this, the bass sound of your speakers will be wrong, even if you use a subwoofer.

 

[ragnarok775]

Wow, I looked up the T/S Parameters to see how difficult it would be to calculate them myself. I did not know the design of a cabinet involved all of these detailes! Anyway, I will most likely go ahead and refoam these then (even though ill probably butcher the job ).

Thanks for the quick and helpful response.

 

[TLS Guy]

Wow, I looked up the T/S Parameters to see how difficult it would be to calculate them myself. I did not know the design of a cabinet involved all of these detailes! Anyway, I will most likely go ahead and refoam these then (even though ill probably butcher the job ).

Thanks for the quick and helpful response.

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