SDA SRS 2 Crossover Parts list

inspiredsports

I'm also buying the parts to have my SDA SRS 2 crossovers rebuilt.

The crossover board is split into 2 parts in these cabinets, one on the speaker post mount (Top), and one on the separately mounted Interconnect socket (Bottom).

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The top board has 4 resistors. 1 is marked 3.5 ohm 10% 5W and 3 are marked 2.7 ohm 10% 5W. --- There are also 2 capacitors on this board, 1 marked 4.4J 100V with a small black/brown SAN Mexico 50% component (don't know the proper name) piggybacked across it. --- The second capacitor on this top board is "double-wide" and marked 12.0J 250V and also has a small black/brown SAN Mexico 50% component piggybacked.

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The bottom board has 4 Capacitors.

1 is a 34u, 1 I can't see as it it under the "piggybacked caps", but it appears to be a second 34u (does anyone in the group know for sure? THERE IS AN ARROW IN LAST PHOTO WHERE HIDDEN IS)

The 3rd and 4th caps are marked 130u piggybacked with 55u (but they seem so large I'm wondering if they are 5.5 and 13.0) ???

First, which should be Sonics and which can be Daytons, (or should I invest the $$ in all sonics)

Last, what are the other small (resistors?) on the board not mentioned above, and should they be replaced too?

Thanks in Advance,
Greg

zingo

The little ones would be bypass caps and they do not need to be replaced since you will be using quality components. I have always used one brand for the entire build, but I know others have split the highs and lows like you are referring too, and I'm sure they will chime in. I rebuilt my SDAs with all Sonicaps with great results.

ben62670

The 130, and the 55 = 185uf. That is a large value cap for sure. You can use 2 caps to reach a value of 180-190uf and be fine.

inspiredsports

I'm getting good related information here, and in my other thread about rebuilding my other (2B) crossovers.

2 things I still haven't figured out--
-- The value of the cap that is hiding under the piggybacked ones. Does anyone have a schematic showing for sure if it is a second 34u? I hate to take it apart just to see the value.
-- I don't know which caps on this project (SRS 2) should be Sonics, and which could be Dayton's if I choose to save the dollars.

inspiredsports

In my other thread I learned that many upgrade the 2B to the SL3000/RDO-198 replacement (instead of the stock SL2000/RDO-194 replacement). Is the 198 ever used to upgrade the SRS 2 also? What cap values would it change?

Face

inspiredsports wrote: »

In my other thread I learned that many upgrade the 2B to the SL3000/RDO-198 replacement (instead of the stock SL2000/RDO-194 replacement). Is the 198 ever used to upgrade the SRS 2 also?

No..

inspiredsports

That's a great answer! Now I only have to worry about trying to return 2 as yet unreceived RDO-194's that I ordered Wednesday.

Face

As for your earlier question, you can save a little money by using Daytons for the large value caps such as the 55, 130, etc... For this speaker, the tweeter circuit is more important.

NJPOLKER

I placed an order with Parts Express Tuesday to upgrade the low pass on my SRSII's
2 Dayton DMPC 100uF @ $23.43 ea
2 Dayton DMPC 90uF @ $20.29 ea
4 Dayton DMPC 33uF @ $9.63 ea

This is what I ordered for the high pass a year ago from Sonic Craft Resistors were all $3.50 ea
6 Mills resistors 2.7 ohm
2 Mills 3.5 ohm
2 Sonicaps 4.4uF $24 ea
2 12uF $$40. ea

I think that about covers it all.
Good luck
Drew

NJPOLKER

Also, since your on a roll you may as well buy some Dynamat and do the drivers and passives. Don't forget the binding posts. P.E. has a sale on some things and I decided to try the premium binding posts at $13. a pair, hard to beat that unless they really suck.

inspiredsports

Thanks! Concerning the Dynamat, If I use Mortite to seal, is damping the frame of the passive and drivers still necessary?

Face

Definitely.

inspiredsports

Thanks to many for so much good intel

In my SDA-2B crossover parts list thread, I learned the pricing difference to upgrade the 20uf and 40uf Dayton low pass caps to Sonics is + $108.86, and there is a better listening experience to be gained.

With Sonic Caps maxxing out at 30uf, it seems like it's not possible to upgrade the SDA SRS 2 crossovers which need 34uf in two spots, and 185uf in the other.

Are there other / better options besides the Dayton's for the SRS 2's, or are we splitting hairs here?

NJPOLKER

Call Sonic Craft and discuss your needs with Jeff and or Elliott. IIRC they can make some larger value Sonicaps. As stated before no need for bypass caps. Maybe you should try out the Aeon caps for the low pass which you can get from Sonic Craft along with the Sonicaps and Mills resistors. You could use Solens,Aeon or others that are more affordable because the low pass is not as critical an application as the high pass, at least thats what I have learned. I am using Daytons because I have used Solens in other speakers and want to try another cap also they are on sale at P. E.
Drew

NJPOLKER

inspired
Have you tried to remove the crossovers from your cabinets yet?
I had some complications removing the high pass x-over because of the adhesive used to seal around the nut holding the x-over in place. You'll see what I mean or have seen what I mean when removing them. If you have this problem just be patient and remove the adhesive. black in my case, and get a socket,extension and ratchet to hold the nut while unscrewing the bolt with a allen wrench. Be sure to reseal that area as well as all areas so you have no hidden areas where air can escape.
Drew

inspiredsports

Hi Drew,

I have not removed the crossovers from the SRS 2's yet. I just picked these speakers up last weekend and want to get to know their stock sound a bit before breaking them down. Thanks for the tip!

My SDA-2B's are going to get their upgrade first as I have a 21 yr baseline on them (and their high pass caps are starting to bleed yellow goo).

I just want to get all parts ordered for both to save shipping and hopefully get the Sonic 20% November discount on all (unless their December discount is 25%).

Also, you mentioned Dynamat. Boy is it expensive (and I'm sure worth it), but have you seen thread #20 in the post at http://www.polkaudio.com/forums/showthread.php?p=952030#post952030

NJPOLKER

It cost me about $20.00 to do my SRSII's and SDA2a's using more Dynamat Extreme than needed on the baskests. I even had some left over. The Dynamat Extreme was easy to work with. Just cut the strips to proper width & lenght and work it into any creases real well.

inspiredsports

I must have seen a Dynamat Extreme kit to do a bus or something because it was over $200. I'll fine tune my search.

I guess this 4 square foot pack on sale for $14.99 + S&H would do the trick from http://www.sonicelectronix.com/viewitem.php?id=3131

I'm still going to do more to explore #20 in the post at http://www.polkaudio.com/forums/showthread.php?t=74734 that says Mortite will do it all.

NJPOLKER

Do both

inspiredsports

Dynamat Extreme made it onto my parts list today and I purchased the 4 square foot 10425 Xtreme Wedge Pack (1 Sheet 18" x 32") for $17.99 + $6.47 S&H = $ 24.46 at . . .

http://www.amazon.com/exec/obidos/AS...bsitementcommu

Thanks

inspiredsports

My last project is rebuilding the low-pass crossovers in these SDA SRS 2's. The original T.I. caps on the low side look absolutely shiny and new and in perfect shape, but I'm fairly sure new caps will impart a sonic improvement over these 22 year old beauties.

I've just received all Sonic Caps and Mills for the high-pass rebuild, but held off buying the lows as Sonic Craft does not go beyond 31.5uf with their Gen I caps.

If I mix Sonics and Aeon, I need a total of:
8 Sonic 17uf @ $25.40 each = $203.20
2 Aeon 100uf @ $18.76 each = $ 37.52
2 Aeon 82uf @ $16.28 each = $ 32.56
TOTAL: $273.28

Using ALL Aeon, I need a total of:
4 Aeon 33uf @ $7.74 each = $30.96
2 Aeon 100uf @ $18.76 each = $ 37.52
2 Aeon 82uf @ $16.28 each = $ 32.56
TOTAL: $101.40

ALL Aeon yields a SAVINGS of $172.24 !!!

I guess the big question is, will I HEAR the difference if I pay up for the Sonics ???

Can anyone weigh in with their experiences / opinions?

inspiredsports

I went ahead and pulled the trigger for the low-pass crossover yesterday using Sonicaps where I could!

8 Sonicap 17uf @ $25.40 each = $203.20 LESS 20% = $152.40
2 Aeon 100uf @ $18.76 each = $ 37.52
2 Aeon 82uf @ $16.28 each = $ 32.56
TOTAL: $222.48

I aslo decided to upgrade the Speaker Binding Posts with 2 pairs of Cardas CCGR-short at $32.25 each

This, along with the ALL Sonicaps and Mills on the high-pass, 4 new RDO194-1's and 4- 6.5 Polk drivers in the stereo spots, Mortite and Dynamat should certainly yield some equisite sound when this recipe is fully cooked!

NJPOLKER

Great work !!
What else can I say!!!!
Drew

inspiredsports

Next step is to research and learn if this original 4 ohm, separate low-pass/high-pass crossover version of SRS 2 is able to be re-wired for bi-amping, or modified for use with the A1 IC with mono amps!

I have and NAD 7600 and have a chance to obtain an NAD 2600A for a song, but then I'll be "all dressed up with no place to go" if I can't bi-amp or go mono.

inspiredsports

I went crazy and applied Dynamat Extreme to my Passive Radiators. I double guarantee there is no "ring" to them now and they gained about a pound each!

Notes:
--- Be very careful when handling the spokes not to jam your fingers into the manilla colored radiator suspension material just under the back (smallest diameter end) of the radiator.
--- Be sure to avoid direct contact with the backside of the radiator material.
--- I felt it was best to hold radiator by the spokes when pressing Dynamat on (with a small rubber wallpaper seam roller sometimes called a "breyer) rather than putting pressure on the rubber boot of the front of the radiator.

I'm pleased with the results, but can't listen yet as RDO194-1 tweets and all Sonicaps/Mills (upgraded by ben626701) high-pass crossovers are in transit.

Applying Dynamat to MW6509 6.5" mids is next.

F1nut

Tip: You don't need to cover every inch of metal, just apply a strip to every spoke, that's more than enough.

Face

I found that even with all the spokes covered, there was still a little ringing on the end cap. Four 1"x1" pieces solved that, I didn't need to totally cover it either.

NJPOLKER

Some of us just get carried away with the Dynamat Its so easy to work with I decide what the hell Dynamat it if it does not move!
Drew

inspiredsports

F1nut wrote: »

Tip: You don't need to cover every inch of metal, just apply a strip to every spoke, that's more than enough.

You are absolutely right. I experimented first with perhaps 2 square inches on the ring and a 1 x 3 on each spoke and it absolutely deadened the ring. I over complicated it for aesthetics because I think it looks cool.

inspiredsports

I have 100% of my parts purchased, upgraded, and in place for final assembly. The first point of attack is installing the low pass inductor and crossover board, with a small twist.

The inductor / low pass crossover assembly on early model SDA SRS 2's mounts to the the back wall of the cabinet. It's location is exactly centered behind the back of the passive radiator. If you were to strip all of the components off of the circuit board, the "gap" left to install inductors/caps/etc. before you would hit the back of the passive is 3-1/8". The original factory version leaves a 1-3/8" gap from the highest component on the board (one of the smaller inductors).

The desire to use higher grade caps (Sonicap and Aeon) presents an engineering problem because of their size. The board originally had 2 34uf's and piggybacked 130+55=185uf in the space needed for just 2X17= 34uf upgraded Sonicaps.

The work-around is to fit both 2X17=34uf Sonicap piggybacks on the borad, and move the huge 100+82= 182uf Aeons off of the board using silver wire. My problem now is deciding how best to mount the loose giant Aeon's to the cabinet.

The SDA SRS 2 has a triangular brace perpendicular to the back of the cabinet located just below the original low pass mount.

I'm thinking of simply drilling a couple of small holes through triangular brace and using a couple of cable ties and a dab or two of holt melt glue.

DOES ANYONE FORSEE A PROBLEM WITH THIS LOCATION ??

ben62670

That would be just fine, or the brace above. You can use any type of open cell foam to pad those huge caps;)