SDA-SRS 1.2tl redux...

nooshinjohn

Today I have become the proud papa of a needy pair of a set of 1.2's. This will be my third go-round with the big girls, and I cannot wait for them to come home. They are in need of some love and affection(grill cloth/new wood/upgrades) but perform nicely as they are. I am happy to be the one to give these a home. My wife is on board as well this time, and will be helping to decide if the Polks or the Magnepan MG-20's will be the ones that stay permanently. Given the fact that the Maggie's need at least 5 feet off the back wall to the Polks needing 6 inches.... I think I already know what the outcome will be.:cheesygrin:

P.s. a big thanks to Jesse for the good vibes sent my way via an a1 interconnect. There has not been a set of srs 1.2 tl's offered locally in two years, and within a month of getting the cable, the heavens opened. You are a good man Jesse!

Oldfatdogs

Congratulations on set # three.
Dan

headrott

Nice John! Let us know when the upgrades start. Glad to have you back in the Polk Family again with your newly aquired 1.2TL's. Do you have some pictures of them?

PolkieMan

3 sets of 1.2tls, wow.But no pictures:surprised:

headrott wrote: »

Nice John! Let us know when the upgrades start. Glad to have you back in the Polk Family again with your newly aquired 1.2TL's. Do you have some pictures of them?

gimpod

Congrats John, Let me know if there's anything I can do to help you with bring them back.

Drenis

Congrats

dpowell

Nice Score John! Can't wait to come up and give em' a listen.

PolkMaster1

Nice score John. What happened to the other two? And what happened with the tweeters I sold you?

F1nut

Third time's the charm, so you better keep this pair.

chandler9a

Congrats on the find, keep us posted on how it all turns out.

civilian

Congrats John wouldn't mind being there when you pop them open.

phocion

Glad to see them in proper hands, I was hoping someone from the club would snag them!

drumminman

Congrats NJ! I bet they're gonna sound nice with those monster tube amps.

nooshinjohn

That is what I am hoping. The list of mods these are going to get is extensive to say the least. I need xo's, rings, xo covers, grill cloth, added bracing, sealing the tweeter section from the mw's and running a divider internally between the sda and stereo drivers. By the time these are done they will be new in all respects except for the drivers.

I am giving thought to construction of entirely new cabinets patterned after the current LSiM 707's/RTiA lines in terms of shaping, but still retaining the exact internal volume and front baffle configuration. I plan to have a lot of fun with these.

PolkMaster1

nooshinjohn wrote: »

That is what I am hoping. The list of mods these are going to get is extensive to say the least. I need xo's, rings, xo covers, grill cloth, added bracing, sealing the tweeter section from the mw's and running a divider internally between the sda and stereo drivers. By the time these are done they will be new in all respects except for the drivers.

John -

I too wondered what the 1.2 TL would sound like if the SDA drivers were partitioned off from the main driver section. Has anyone tried this?

nooshinjohn

PolkMaster1 wrote: »

John -

I too wondered what the 1.2 TL would sound like if the SDA drivers were partitioned off from the main driver section. Has anyone tried this?

I don't think anybody has tried this yet. I have been wanting to try a few new ideas to improve the breed.

nooshinjohn

Got them home a few hours ago... man do they sound good! Forgot how much I love sda's.

Bigerik

There ain't nothing in the world like SDA's. I'm insanely jealous!

indyhawg

Nice speakers, John. Post some pics whenever you get a chance.

Schurkey

First Guess: It is IMPOSSIBLE to separate the SDA drivers from the Stereo drivers, because they are both intended to provide pressure pulses to the passive radiator. Therefore the common chamber around the PR will provide a path for the pulses of the SDA drivers and Stereo drivers to interact.

nooshinjohn

I don't intend to isolate the stereo and dimensional arrays completely. The idea is to put a divider between them that is centered between them and extends about 4 inches below the bottom pair of drivers. The idea is to controll some of the interaction between the arrays but not impede air pressure to the passive.

F1nut

I've got to think that if there was any advantage to separating the drivers, Polk would have done that originally. The fact that they didn't tells me there's damn good reason they are not.

pitdogg2

F1nut wrote: »

Third time's the charm, so you better keep this pair.

heck I wish i had just one pair you make me sick John.....:eek:
just kidding Yes i bet those amps will make a good pairing. I do wish you still lived closer I'd love to hear both of those babies.
SWEEEEEEET

nooshinjohn

F1nut wrote: »

I've got to think that if there was any advantage to separating the drivers, Polk would have done that originally. The fact that they didn't tells me there's damn good reason they are not.

Back when these were designed, there was as much trial and error going on as there was engineering. The SRT's do separate the arrays, and a peek inside the LSiM shows just how far things have come from the days if puting drivers inside a box. My ultimate goal is to completely re-imagine the cabinets of these speakers and improve bothe the performance and aesthetics of these speakers... think something along the lines of the LSiM 707 meets SDA in a bar one night, get drunk, one thing leads to another and, well you get the picture.

leroyjr1

nooshinjohn wrote: »

Back when these were designed, there was as much trial and error going on as there was engineering. The SRT's do separate the arrays, and a peek inside the LSiM shows just how far things have come from the days if puting drivers inside a box. My ultimate goal is to completely re-imagine the cabinets of these speakers and improve bothe the performance and aesthetics of these speakers... think something along the lines of the LSiM 707 meets SDA in a bar one night, get drunk, one thing leads to another and, well you get the picture.

Wish Polk would do like Klipsch and remake and improve their older speakers. Can you amagine SDA's with the clarity and accuracy of the lsim's with a wide and inviting soundstage.

nooshinjohn

leroyjr1 wrote: »

Wish Polk would do like Klipsch and remake and improve their older speakers. Can you amagine SDA's with the clarity and accuracy of the lsim's with a wide and inviting soundstage.

Cabinet architecture has much to do with the sound. It is the one area of mods that has not been tried yet. According to the guys at Polk, so long as the layout of the baffle is unaltered and cabinet interior volume is preserved, at the very least, they will look much better, and sound the same.

What I intend to do is build new XO's using Gimpod's boards and otherwise fully hotrod these first, keeping the original parts as reference. Once that is done, I will build the new cabinets and transfer parts to the new, one speaker at a time. The differences should be immediately apparent between the two.

I expect reduced cabinet resonance, better clarity and a more coherent presentation from the new cabinets, but if I am wrong, I will be left with beautiful SDA's that have WAF for the very first time!

F1nut

According to the guys at Polk, so long as the layout of the baffle is unaltered and cabinet interior volume is preserved, at the very least, they will look much better, and sound the same.

Yeah Ben tried that, sounded like crap by all accounts.

Toolfan66

I wish I would have tried that when I had the extra set of cabinets..

PolkieMan

Well I can't tell where you live otherwise I would like to buy the old empty cabinets when you are through with them:cheesygrin:
please let me know, thanks

nooshinjohn wrote: »

Cabinet architecture has much to do with the sound. It is the one area of mods that has not been tried yet. According to the guys at Polk, so long as the layout of the baffle is unaltered and cabinet interior volume is preserved, at the very least, they will look much better, and sound the same.

What I intend to do is build new XO's using Gimpod's boards and otherwise fully hotrod these first, keeping the original parts as reference. Once that is done, I will build the new cabinets and transfer parts to the new, one speaker at a time. The differences should be immediately apparent between the two.

I expect reduced cabinet resonance, better clarity and a more coherent presentation from the new cabinets, but if I am wrong, I will be left with beautiful SDA's that have WAF for the very first time!

nooshinjohn

here are a few pics...