Which crossovers are better SRS or 1.2TL

ben62670

I am building my crossovers from the Polk original diagrams. I have the option to build the SDA-SRS, or the SDA-1.2TL. I will be upgrading to the silk tweets. The main difference is the IC cable between the two. If anyone has listened to both speakers in the same type of setup the thing I am most interested in is the sound stage.

Thanks
Ben

heiney9

ben62670 wrote:

I am building my crossovers from the Polk original diagrams. I have the option to build the SDA-SRS, or the SDA-1.2TL. I will be upgrading to the silk tweets. The main difference is the IC cable between the two. If anyone has listened to both speakers in the same type of setup the thing I am most interested in is the sound stage.

Thanks
Ben

Just one small note: If you decide to upgrade to the TL x-over be sure to order the proper silk replacements. The non "TL" version originally used an sl2000 and the RD0194 is the correct silk replacement. The "TL" series originally used an sl3000 and the RD0198 is the correct replacement. It's my understanding that there are differences (audible) if the incorrect tweeters are used with the incorrect x-over. Might as well get it right the first time around. There is lots of good info on x-over rebuilding/upgrades for SDA's on the forum if you haven't look in the archives already.

H9

ben62670

Thanks Heiney
I do have the SDA book, and thanks for the heads up on the tweets. What I am really interested in is the the staging difference because of the way the the ICs are wired.

Thanks
Ben

heiney9

Also the main difference is in the "sturdiness" of the connection. The SDA cable in both instances has the signal running thru only one lead the others are there to "support" the connection in the slot. If F1 or another very seasoned SDA guru sees this thread they should be able to add a few more specific details. But from what I remember the differences are purely functional and both carry the same info in the same way.

ben62670

Looking at the SRS diagram the hot and the ground are shared between the 2, and on the 1.2's the ground only is shared. It kinda makes me wonder how that works with ground only carrying the signal.

Thanks again
Ben

F1nut

It boils down to personal preference, some like the SRS better, some prefer the 1.2TL. The 1.2TL is more versatile in that with an AI-1 interconnect, one can use non-common ground, dual mono and mono block amps.

ben62670

Thanks F1

Ben

DarqueKnight

ben62670 wrote:

I am building my crossovers from the Polk original diagrams. I have the option to build the SDA-SRS, or the SDA-1.2TL. I will be upgrading to the silk tweets.

You did not explicitly state this, but I assume you are attempting to modify a pair of SDA SRS's? If this is the case, the 1.2TL crossover will not give satisfactory sonic results if it is installed in a SDA SRS cabinet and may even pose a fire/safety hazard for the following reasons:

1. Crossovers are designed to interact with the electrical characteristics of specific drivers and tweeters. The SRS and the SRS 1.2TL use different drivers and tweeters, which constitutes a completely different impedance load on the respective crossovers. The SRS uses eight MW6503 drivers (6.8 ohms each) and four SL2000/RD0194 tweeters (7.5 ohms each). The SRS 1.2TL uses four MW6503 drivers (6.8 ohms each), four MW6511 drivers (3.2 ohms each) and four SL3000/RD0198 tweeters (5.6 ohms each). [Note: These ohm measurements are not the actual AC impedances of each driver, but rather, the DC resistances measured by an ohm meter.]

A forum member installed RD0198 tweeters in his SRS's and it caused his amp to shut down.

2. The cabinets of the SRS and SRS 1.2TL are completely different and have completely different acoustic signatures.

ben62670 wrote:

The main difference is the IC cable between the two.

No. The only thing the SRS and SRS 1.2TL have in common is that they both use four MW6503 drivers. Everything else is different. [See page 49 of the Compendium.]

ben62670 wrote:

If anyone has listened to both speakers in the same type of setup the thing I am most interested in is the sound stage.

I currently own both the SRS and the SRS 1.2TL and have evaluated both in the same system/listening environment. [See pages 58 and 59 of the Compendium.]

ben62670 wrote:

I do have the SDA book...

Lots of good info in that book.;)

DarqueKnight

heiney9 wrote:

Also the main difference is in the "sturdiness" of the connection. The SDA cable in both instances has the signal running thru only one lead the others are there to "support" the connection in the slot... But from what I remember the differences are purely functional and both carry the same info in the same way.

No.

In the blade/blade cable, each blade is connected to a separate wire and carry different signals.

In the pin/blade cable, both cable wires are connected to the pin. The blade just serves for additional mechanical support.

SDA SRS 1.2

DarqueKnight wrote:

Lots of good info in that book.;)

AMEN to that! As the owner of a pair of 1.2's (non-TL) I feel like I have a "hybrid". Still sounds great, 'tho!

heiney9

DarqueKnight wrote:

No.

In the blade/blade cable, each blade is connected to a separate wire and carry different signals.

In the pin/blade cable, both cable wires are connected to the pin. The blade just serves for additional mechanical support.

Thanks for clearing that up DK.