SDA SRS 2 Power Requirements

PILAC

Hello,
About a year and a half ago I acquired a pair of 1986 blade blade SDA SRS 2 loudspeakers. I had a little trouble getting sound out of them at first as they did not have an inter-connect cable. I purchased a 220 watt max Yamaha receiver to "get by" as I am not quite in the audiophile budget. Everything works fine and all the drivers move and there is sound coming from the tweeters, but I have noticed a lack in bass output. It is by no means extreme and there is still a decent amount of bass, but in many instances my passive radiators are put to shame by an 8" Klipsch ported sub. When listening to songs with a lot of drum hits such as the drop on "in the air tonight" by Phil Collins the bass drum hits are heavy and full. I assume because all four active drivers move out giving the passive speaker a big "punch". The issue arises with what might be described rumbling bass and organ pipes. There are many of these low tones that I simply cannot hear let alone feel. I realize that the passive radiators won't move as much as an active woofer but from what I've read they should be able to hold their own. As I said before all the drivers are moving including the radiators, putting my ear in the general vicinity of the passive radiators brings a kind of painful pressurized sensation regardless of the type of music. I assume that they are putting out extremely low bass. I was wondering if it was a lack of power causing the problem because I know that the max of 110 watts per channel I can give then now is about 1/2 of the 200+ watt recommendation. I've also been told that it's just how the radiators are and depending on what I want, the loudspeakers might need to be supplemented with an active sub. Is this the case? I was looking at the Crown XLS 1505 which would get me up to 525 watts a side on the 4 ohm load. I assume that the amp would be enough as far as power goes but I am also open to suggestions!

pitdogg2

Are they sealed good no air leaks? How far off the back wall are they?
Are the speakers spiked?
Pro audio amps may not be the answer either.

VR3

I mean atleast 200 watts... Duh

Quality over quantity! Quality watts go a long long way

JayMX

@PILAC - I have the same speakers. They’re awesome! I started with them on a 185wpc B&K amp and they sounded great. When I moved up to an Adcom GFA-555 - 325wpc @ 4ohms. They really came alive. I've found that the preamp makes a ton of difference too. I’ve experimented with modern Marantz, 90’s vintage Yamaha, vintage Marantz, vintage Sansui and vintage Kenwood. The tone controls on my old Kenwood KA-8150 - pre out to the Adcom makes a killer combo to my ears - the Kenny's internal power amp surprisingly doesn’t do half bad either... Despite the speakers' relatively high sensitivity, high current seems to be the secret sauce. Excellently sealed cabinets, placement and room configuration play into performance majorly as well. I’m sure others will chime in with other great suggestions. Good luck!

PILAC

Thanks for all the feedback! in response to pitdogg2 as far as I can tell they are sealed fine there are no cracks, they are not spiked (I only ever had the regular feet) and both speakers are about 3 inches off the wall.

JayMX- Thanks for the suggestion, The Adcom GFA-555 and Kenwood KA-8150 are definitely something I will look into. Sounds like a vintage amp will be the best choice here.

pitdogg2

Snug up all screws, the air leaks in most cases come from stripped screw holes or loose drivers/passive radiator and binding post cups.
If any screw holes are stripped or just can't get snug I'd suggest a quick fix of toothpicks and Elmer's glue. Dip toothpick in glue spread into hole then take two three dip them in glue and tap into hole and let dry. Snip them of the next day. The proper fix would be hurricane nuts and new hex head cap screws. That takes a dedicated effort and slow methodical work drilling out holes and pulling in the hurricane nuts carefully.

PILAC

Sorry for the delayed reply, I believe that this is my problem as I tried a phase test for the drivers and they do seem to be in phase. There were definitely a few loose screws on the lacking speaker and two or three screws on the passive radiator which don't seem to tighten at all. If I did the fix you mentioned above would it prevent me from doing the more complicated upgrades later such as the hurricane nuts and hex head cap screws?

pitdogg2

If I did the fix you mentioned above would it prevent me from doing the more complicated upgrades later such as the hurricane nuts and hex head cap screws?

No since you will drill out the holes to fit the hurricane nuts.

You could also use epoxy instead of Elmer's glue. A few folks have also use epoxy in the holes for the hurricane nuts to help solidify the MDF around the hurricane nuts and also help hold them in place.
I let those who have done the hurricane nut modification chime in on what works best as I've not used them myself.

PILAC

Hello again, I have found what I believe may be a good deal on a pair of Sonance sonamp 260's the MK I version. I am open to any feedback on this model but was told by a custom installer who used to do a fair amount of work with these amps that it would be possible to connect them together giving me more power. I was wondering if this was possible as I haven't really been able to find an article explaining what I want to do. I did find one Wikipedia article which I am taking with more than a grain of salt considering Wikipedia's reputation, it claims that wiring the amps together is possible however it wit cut the number of ohms in half meaning that with 4 ohm speakers even the 2.5 ohm lower limit of the Sonance isn't up to spec. Is this true and could it be avoided?
Thanks

pitdogg2

Which SDA srs 2 if blade/blade interconnect no you cannot.
If they have pin/ blade maybe but you need a dreadnought or AI-1 interface cable and then it is a HARD maybe - maybe not.

PILAC

Thanks for the reply they are Blade Blade. So this means that I need 1 amp that can drive both speakers?

pitdogg2

PILAC wrote: »

Thanks for the reply they are Blade Blade. So this means that I need 1 amp that can drive both speakers?

Yes you must use a COMMON ground amp. You cannot used any that invert one channel or have too much resistance between the negative posts.

PILAC

Just curious, what do you all think of the Belles 350a? It seems like a great amp from what I've read and seemed to meet forum approval in this discussion on SDA amps.
https://forum.polkaudio.com/discussion/136634/best-amplifier-for-sda-srs-2-speakers
(Must copy and paste)
I found a deal on the reference V2 and was wondering if someone has had this amp in the past or could point out any glaring issues I've missed. I'm also always open to suggestions for an alternative or another type of amp altogether.

PILAC

Sorry about that, the link became active after I posted so you should be able to just click.

engie490

I think someone here has (or had) a V2...not sure which speakers he had them on though.

I have a 350A (pre-Reference) and it is an excellent amp. I just haven't connected it to my SDS SRSs yet.

It "only" has about 23db of gain so it works well with preamps that can put out some voltage. Most amps have 26-29db of gain. It will tend to sound less forward.

audioluvr

I have the 350A Reference V2. Great amp.

PILAC

Any reason why someone might want to upgrade?

PILAC

From the Belles to another amp.