SDA 2 Newbie - Have Questions - Need Advice

jjklongisland

OK, so I did something I normally dont do. I went on Craigslist and bought a pair of used Polk SDA 2's off an older gentlemen who is obviously really into vintage audio equipment. Since he had so many pairs of different speakers I figured either I could find a nice set for my 2 car garage mancave or even possibly score a set of decent speakers for my new home theater under construction. He told me these SDA 2's were "audiofile" grade speakers and when he played them in his very small den they really sounded great. I listened to big 15" cerwin Vegas, and a few other models. I was very surprised at how great the older Polks sounded so I bought them for $200. The cabinets themselves are a little rough and they are missing the grilles but I figured what the heck, and he could use the money. When I brought them home to try them out in my garage I connected them to my basic 2 channel budget yamaha receiver I bought specifically for bluetooth to power a set of old pioneer tower speakers for garage listening while wrenching on cars. While at low volumes they sounded great but when I started to crank them the two mid range speakers (on the right channel) started to **** and distort. I immediately got disappointed and thought I wasted my money and should have just bought a new set of Elacs for my home theater at Best Buy. Then I started doing more research. The reviews on these old polks are amazing and alot of people swear by them. I then called the guy I bought them from and wanted to see if he would take them back or trade them for a pair of B&W bookshelfs he had. He told me that it would be a mistake and that the Polks were alot better speaker its just I had a crappy amp connected. He told me about the 4 ohm etc and then I had to educate myself on ohms and power etc. Hopefully the basic receiver I was using to power these is the reason at high volume they start to distort (dont know why I only experienced on the left side) and they had no bottom end. That leads me to my current predicament requiring advice.

Either

A: Shell out $1300 for a new Marrantz 9.2 receiver that has enough power to push these and use them for my home theater and buy a center channel and rears (I have my heart set on a SVS 1000PB sub) that would compliment these vintage bad boys or

B: Stick with a moderate new reciever Onkyo or Yamaha Avantege for around $600 and add a separate amplifier just to power the Polks or

C. Scrap the old polks and invest in a new hometheater sound system with a total budget of $2200 all the while wondering if I blew an opportunity to have a better system with the vintage polks, or

D : Dont use them for my home theater, keep them for the garage and wait for a decent used amp to connect to my basic yamaha stereo receiver.

If I was going to keep these Polks as home theater front channels, what would be a good center channel that would go well with these? I was always told that the front 3 speakers should match brand and series etc but these are old.

Lastly, I realized that these Polks should have came with an interconnected cable that wakes them up even more. Would I need that in a 5.1 set up or will that mess up the tech of a new receiver etc.

Overall finished basement size is 25'x16' but the area that my theater is going is about 18'x 13' but is open to the rest of the overall finished side.

jjklongisland

I just with Onkyo regarding their receivers and they told me that its not good idea to mix 4 ohm speakers with 6 or 8 ohms because things tend to fry? If thats true it adds a new dynamic to the equation....

pitdogg2

jjklongisland wrote: »

I just with Onkyo regarding their receivers and they told me that its not good idea to mix 4 ohm speakers with 6 or 8 ohms because things tend to fry? If thats true it adds a new dynamic to the equation....

yes that can be hard on a receiver. The question is what SDA2 do you have? There are 3. SDA2 SDA2a and SDA2b. SDA2 and SDA2a are both 4ohm and can dip low to almost 2ohm at certain frequencies. Those two are both better suited to Amplifiers.

FestYboy

I can't imagine any version of the 2s having a lack of bass... Did they come with the interconnect cable? Do they pass the air bleed test?

jjklongisland

Thanks for the response guys. Bear with my lack of knowledge in this subject. Trying to get a crash course. The back of the speaker just says SDA 2 serial number L SDA II 10675. They have 1 tweeter, two mids, and woofer. I do not have the interconnect cable. Haven't done any testing since I would have to hit up youtube to figure out how to do it. I think I have come to the realization to find a decent amplifier and keep them as garage speakers. My garage is 24'x34' so large speakers will do well in there.

Can anyone recommend a decent amplifier that will push these.

pitdogg2

Picture of front. Is the interconnect socket blade/blade or pin/blade

jjklongisland

pitdogg2

Pull the top drivers sda2a will be 2x 6510
Sda2b will be 1 6503 and 1 6511. Do not put them back in the opposite hole if the latter

jjklongisland

ok... thanks for the help. I will do in the morning. 4 hours of speaker research after work is causing my brain to scramble...

pitdogg2

My money is on sda2a 4ohm and dip much lower. Receiver killer they are.

verb

@jjklongisland have you checked out this sticky? I always start here when doing my research. Good stuff from @VR3 !
http://forum.polkaudio.com/discussion/133384/all-the-polk-sda-upgrades-located-in-one-place/p1

westmassguy

They look like 2As with real walnut veneer. Never seen them with fiber gaskets on the woofers though.

jjklongisland

I will have time to find out after work tonight. Had to work late last night...

jjklongisland

Nightfall

Looks like your midwoofers have been replaced by a previous owner with some old ones.

verb

Interesting on the driver numbers. Found this in another thread with the same driver question.

http://forum.polkaudio.com/discussion/113321/polk-7as-are-they-worth-fixing

jjklongisland

So is it a coincidence that numbers are kind of inverted. 6510 vs 1056?

Also my uncle is giving me his Soundcraftsmen 410 watt rms PM840. Hopefully these can push these...

RandyCroissant

Interesting for sure, even the cabinets look odd to me. Could be a very early 2A

verb

jjklongisland wrote: »

So is it a coincidence that numbers are kind of inverted. 6510 vs 1056?

Also my uncle is giving me his Soundcraftsmen 410 watt rms PM840. Hopefully these can push these...

Not sure, but good catch! Early Monitors as far as i could glean. Maybe other more esteemed and knowledgeable Polkies can opine!

jjklongisland

Found this right up in a spanish version of eBay after doing a google search n the following: 1056 speaker x 1261

you are buying one Polk Monitor 10 Midrange Driver, a 6 1/2 inch speaker. It came out of a Polk Monitor 10 speaker cabinet that I bought in 1978. This is an earlier version, before the 10A and 10B cabs. The markings on the back are stamped, not on a paper label. The markings, stamped in red ink, are "X, 1261" "1056" and "7815", along with a large number handwritten with a black felt maker, probably a Sharpie. The "1056" and "7815" are smeared but I'm pretty sure that's what they say. As far as what these numbers mean, my guess is "7815" is a date code: the 15th week of 1978. The handwritten numbers may function as serial numbers for Polk's test or inventory records. I don't know what the other stamped numbers mean. The "10" of "1056" may mean the driver was destined for the Monitor 10. This driver comes out of a cabinet that was in frequent use, by me in my home, up to about two months ago when I had to decommission the cabinet due to size and weight. The driver is in good working order. Placing my ohmmeter across the terminals gives me a reading of 6.5 ohms. The impedance is 8 ohms.

verb

Yep I seen that one too. Didn't have to run it through Google translator though!

F1nut

Someone did a really bad job reveneering those cabinets.

westmassguy

F1nut wrote: »

Someone did a really bad job reveneering those cabinets.

Plus the wrong woofers, should be MW6510s. Lord knows what shape the crossovers are in.

jjklongisland

Judging by the recent comments this is all making me more nervous realizing I may not have bought what a true unadulterated SDA-2. Looks like I will be having a chat with the guy that sold them to me...

F1nut

Your best bet at this point is either return them if you can or sell off the parts. I would not put another red cent into those.

jjklongisland

westmassguy

Crossover looks unmolested