Sda2

brgman

I have a nice pair of original 3 middie SDA2's and need to decide whether to spend $$ to do any upgrades or just try and sell them.
Would like opinions on investing in these (or not)and what i could do to make them keepers.
TIA
Mike

falconcry72

brgman wrote: »

I have a nice pair of original 3 middie SDA2's and need to decide whether to spend $$ to do any upgrades or just try and sell them.
Would like opinions on investing in these (or not)and what i could do to make them keepers.
TIA
Mike

Common SDA upgrades include:

-Replace tweets w/ RDO-194's
-Replace capacitors and resistors in the crossovers
-Spike'em, especially if they're on carpet
-Dynamat the drivers and passives
-Larry's retaining rings and/or Mortite caulk

There are MANY threads on the forum about all of these upgrades, so search away...

If you love the sound of SDA's, then the uprades are worth it.

You may want to get your ears on a set of SDA's w/out the dimensional tweeter, as many seem to prefer those to the sets with the dimensional tweets, but some prefer the dimensional. Non-dimensional-tweeter-having SDA's would include the CRS+, 2B, 1C, SRS, SRS2, SRS 2.3(tl), SRS 1.2(tl), and SRS 3.1tl.

brgman

Thanks falcon.I guess a better expalnation is that i have a pair of 3.1tl's,RTA12C's,and RTA 15's.Do i want to screw with the SDA2?Will the upgrades be something worth doing or should i look for 1C's or something?

inspiredsports

In my book you would do best upgrading the rarer and more highly regarded 1990 3.1TL's.

The SDA 2 is an much older (by SDA standards) design (1984) with larger cap values that cost more to replace and a tweeter in the SDA circuit that many believe negatively impacts the sound quality. No modern SDA's have a tweeter in the SDA circuit as the frequencies involved to get the effect can all be handled by the mid woofers.

2 RDO198-1 tweeters at $49 each from Polk and a very small handful of Sonicaps and Mills Resistors from Sonic Craft will make those 3.1's sing!

brgman

3.1's are under construction as we speak.just hate to part with my first set of polks but at the same time i just cannot justify putting too much $$ into the 2's.A set of 1c's would be nice if i can find them.

inspiredsports

brgman wrote: »

3.1's are under construction as we speak.just hate to part with my first set of polks but at the same time i just cannot justify putting too much $$ into the 2's.A set of 1c's would be nice if i can find them.

The 1C's are a great speaker and have a ton of support here, but if you had both side by side and as tweaked as possible, I'd stake a bet that you would like the RDO198-1's in the 3.1TL's better than the lesser RDO194-1's that are as good as it can get for the 1C's.

There's also a lot to be said for the purity/clarity of a single source point tweeter as found in the 3.1 design versus the challenges of a progressive source point multiple tweeter design.

I do appreciate your attachment to your first SDA's and feel the same way about my first Polks which fortunately were walnut capped 2B's; they are completely tweaked and TL'd and will NEVER leave the nest while I'm sill breathing. :biggrin:

It is a hobby after all, so you don't need to justify upgrading the 2's to anyone but yourself. In the whole scheme of things it really isn't that much money to redo them with high grade caps, resistors and new tweeters, even though you won't get quite the bang for the buck as modding the later model SDA's.

brgman

Great insight and advice.I'll finish up the 3.1's and then see how i feel about it although i think i'll throw any upgrade money at the 12c's or 15's next.I saw a pretty cool upgrade on here for the RTA 15TL's.