Polk Audio SDA 3.1TL Modification Thread

VR3

This one is almost wrapped up

Tweeter Network -
Clarity Cap ESA
Mundorf Mox
Jantzen Inductors

Midbass/SDA Network -
Clarity Cap ESA
Jantzen Inductors
Jantzen C Coil

Stock wiring
Lexan substrate
Point to point network
Custom 3D printed connector plate
Round aluminum terminal plate
Gold Plated insulated binding post
13 Awg Supra Rondo SDA Cable, Neutrik NL4

Faustin

Beautiful work and great attention to detail.

VR3

Thank you sir

VR3

These are headed to Singapore

indyhawg

Really nice work, Trey.

VR3

Thank you :-D

honestaquarian

Hey did you use one of @gimpod's boards?
What does that kind of upgrade cost?
(*am I being tacky by asking here?*)

honestaquarian

Right
I was asking because in the first pic there is a black circuit board in the background and it looks like one of @gimpod's boards

machone

I will be rebuilding the crossovers in my 2.3tl's sometime in the near future. I plan to use gimpod's boards. If at sometime in the future I wish to upgrade the internal wiring I assume that the male half of the Mate-N-Lock connectors would need to be ordered so that a new wiring harness could constructed?
If so how are the wires attached to the pins inside the male connector?
Crimped? Soldered?

gimpod

Crimped, Be aware there are 2 sizes of pins to chose from depending on the wire gauge your going to use, 24-18 and 20-14.

honestaquarian

Hey howcome the 3.1's don't get as much love on this forum as all of the other SDA's???
This is the model that I see mentioned the least even compared to the CRS's even.

gimpod

Because they were only made in the last 1 or 2 years of the SDA production and were only about $500 less than the SDA SRS 2.3TL so most went with the SDA 1C ($200 cheaper) or the more impressive looking 2.3TL IMO even the wood 1C is better looking. I'm not knocking the 3.1 there a good sounding speaker they were just an oddball speaker in the SDA line between the SDA 1C and the SDA SRS 2.3TL. Also I don't think Polk made that many of them

honestaquarian

I had the SDA-1B and the SDA-1C. 21 years ago I had a choice between the 1C's and a pair of 3.1TL's. I WANTED the 3.1's,but was in unstable living conditions at the time.So I wound up choosing the 1C's because I had already owned their predecessors the 1B's. 20 years later I had the opportunity to find out just what I had missed and BOY AM I GLAD I DID!!!! (*see my posts on the Laserdisc thread*)

Your point is well taken though @gimpod
One of these days when I get my finances straightened back up I plan on purchasing a pair of your crossover boards as they and you are both legend sir!
Hopefully they won't be sold out by then

Gunther16

IMO the 3.1TL was a result of advancement. Same soundstage as its bigger brothers, improved sonics (IMO), smaller footprint but big, big sound. Back in 1992 I read a review somewhere where the reviewer commented that the 3.1TL was the most audiophile speaker out of the 3 models and I tend to agree. Having had all 3 models in the series at one time or another over the years the only survivor of the family are the 3.1TL which by the way were the first I owned and will be buried with me when the time comes. LOL. Although the bigger brothers were superb their footprint in my environment was just too big. Therefore IMO the 3.1TL's are the better fit of the 3 and thanks Gimpod I love owning rareties with your outstanding boards.
Love my 3.1TL's

Toolfan66

I guess it's just subjective, because I wasn't fond of the 3.1tl's..

honestaquarian

What @Gunther16 said!!!!

gwg_97

Trey -

Did you use two 2.7 ohm resistors to make a 1.3 ohm value for each crossover?

VR3

This has been a while ago I'm unsure but I will parallel resistors to hit certain values so possibly

honestaquarian

I want one of theeeeezzzze

honestaquarian

You got any pics of your progress so far on mine?
Or are you still waiting for the parts to arrive?

VR3

It will be a few more weeks before any pics, the inductors come from across the ocean

honestaquarian

Let me know if they finally get them fancy,schmancy new ones for the tweeters

honestaquarian

Hey Trey
Just curious
When did they stop making the 3.1's?
I could have sworn it was 1991. I just opened mine up to install the Blackhole 5 and do the glue thing and look at what I found.
So far the drivers I have pulled also say made in 1992.

honestaquarian

Oh wait wasn't 1991 the FIRST year they built them??
BACKWARDS!

F1nut

Nope, started production in 1989.

VR3

Almost there (still have to change out those silver bolts for the black ones Carlton wants)

honestaquarian

Trey
NICE!!!! (*understatement*)
Did you mark the internal,upgraded speaker cables? Because I don't remember what goes where.
Also just curious about the difference between mine and the one you did at the beginning of the thread, besides the change to the singe large connector.

VR3

Thank you! Pretty similar, I just have been refining my Fortress V2 line to a "standard work" practice over the past few years.

From a part standpoint, the stereo circuit uses a single cap versus parallel and the tweeter caps are the new CSA series... plus the single connector.

Otherwise, not much difference

honestaquarian

What is the change that using that great big single cap versus the two going to make?

Legender

This work looks awesome. Great job. As a relatively new owner of stock 3.1 TLs I'll be headed deep down this rabbit hole I'm sure.

VR3

Thank you