Will a Adcom GFA-555 amp be enough power to push a set of SDA SRS 2.3 speakers?
tpeveler
Posts: 10
I just bought a set of SDA SRS 2.3 off a man on facebook, they look like new and are all original. I try running them with a Onkyo 100 watt a channel receiver - the results was flat sound and no bass at all. All drivers were putting out sound, so is my problem not enough amp or do you think they need to be recapped or all the above?
Best Answer
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I would urge you to consider doing the TL mod. Since you are ordering the caps now you would only be adding a small cost (2x5.8uf caps). You would also be ordering RD0198 rather than RD0194. The result will be better sound.I'm in the process of ordering capacitors for the SDA 2b right now and going to upgrade them to the RD0194 tweeters.
Also, 60 watts or 100 watts doesn't matter nearly as much as how much current the amplifier is capable of. After all, its and amplifier not a wattifier. I am driving my 2B off of a 75 watt NAD receiver, I had it recapped this summer, and it has 6db of headroom and is capable of pushing a lot more than 75 watts for short periods of time. Its no match for my Parasound, but does the job just fine in a small room.
SDA SRS 2.3tl, SDA 1C, SDA 2B (TL mod), Reserve 200
Answers
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The adcom will work. But both are long in the tooth in the cap dept.
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Thanks, any suggestions on the recap replacement. I can replace the capacitors my self but are there upgrades or should I replace them with the original values except upgrade them to Dayton or Sonic Crafts?
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Sonicap is what most use in the Polk crossovers, but clarity are also a good choice.
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I believe he means the amplifiers- Not Tom ::::::: Any system can play Diana Krall. Only the best can play Limp Bizkit.
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Have you done the PR/air leak test? What size room are they in? How far from the back wall are the speakers?afterburnt wrote: »They didn't speak a word of English, they were from South Carolina.
Village Idiot of Club Polk -
I think something else is amiss here; those speakers should not sound flat or have no bass just because you're using a 100W receiver. I drive my SDA 2B with a mere 60W Adcom and I have no such complaints.
Is everything original to the speakers? What about the interconnect cable? @Nightfall has some good points as well.So, are you willing to put forth a little effort or are you happy sitting in your skeptical poo pile?
http://audiomilitia.proboards.com/ -
I think something else is amiss here; those speakers should not sound flat or have no bass just because you're using a 100W receiver. I drive my SDA 2B with a mere 60W Adcom and I have no such complaints.
Is everything original to the speakers? What about the interconnect cable? @Nightfall has some good points as well.
Totally agree, my 2a's had bass with a receiver but when I got a dedicated amp (which was the adcom gfa555) the bass was just much better and controlled. -
My room size 22 x 26 with a cathedral ceiling. They are placed about 6" from the wall in the back and 4' from the wall on the left side, 7' apart from each other. They are all original including the crossover capacitors. I'm not sure what the PR/air leak test is but if I pus the passive radiator all the bass drivers move in and out with it. Also I was mistaken about my receiver it's 60 wpc instead of 100 wpc. Hope I'm answering everybody questions! I've also have a set of SDA 2b and they also lack bass hooked up to this receiver. I'm in the process of ordering capacitors for the SDA 2b right now and going to upgrade them to the RD0194 tweeters. Now my Polk M4 sounds great on this receiver but they are a lot smaller also.
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Place them closer to the wall, mine are less than 4" off back wall.
Passive test is
1. push quickly in until bottoms out and hold there and watch mid-woofers hold until MW are back at resting position
2. count time it takes MW to recede to resting position
3. the longer the better report back -
Move the seating position. You may be listening in a null region within the room. Your room is nearly square--except for your ceiling, that room would be terrible with standing-waves. About the only way it would be worse would be a flat ceiling that's about 8' high.
The '555 Adcom is well-regarded, but the caps will be far beyond their service life. Could easily result in poor bass due to power-supply degradation. -
Move the seating position. You may be listening in a null region within the room. Your room is nearly square--except for your ceiling, that room would be terrible with standing-waves. About the only way it would be worse would be a flat ceiling that's about 8' high.
The '555 Adcom is well-regarded, but the caps will be far beyond their service life. Could easily result in poor bass due to power-supply degradation.
Agree with first statement. Play some bass heavy tracks and walk around the room and see if you notice any changes in the bass response.
On the second statement, older Adcom amps are notorious for the smaller electrolytic caps leaking on the boards and ruining them. You should have those caps replaced even if they are still good. Fortunately, that should not be too expensive.
The main power supply caps (aka the beer can size ones you can't miss) should be measured by a competent tech to determine if they need replacement. My Threshold Stasis 2 has plenty of bass and appears to have the original main PS caps from 1978! Of course, YMMV...Alon Petite / Infinity 1.2S / Coda Continuum / Counterpoint SA5000 / Oppo BDP-105D / Technics SP-15 w/SAEC WE-308SX & Ortofon AS-309 arms / Ikeda 9C2 & Dynavector XX2 Mk II carts -
Make sure that "Tech" measures both the capacitance AND the ESR.The main power supply caps (aka the beer can size ones you can't miss) should be measured by a competent tech to determine if they need replacement.
Adequate capacitance but with high ESR is still a failed capacitor.
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You are describing the symptoms of speakers that are out of phase. Check the polarity of the connections all the way from the amp to the speakers. It's possible the colors on the binding posts have been reversed. Do a battery test to make sure all the drivers in the speakers are moving in unison.the results was flat sound and no bass at all. All drivers were putting out sound,- SDA 2BTL · Sonicaps · Mills resistors · RDO-198s · New gaskets · H-nuts · Erse inductors · BH5 · Dynamat
- Crossover upgrades by westmassguy
- Marantz 1504 AVR (front speaker pre-outs to Adcom 555)
- Adcom GFA-555 amp · Upgrades & speaker protection added by OldmanSRS
- Pioneer DV-610AV DVD/CD player
- SDA CRS+ · Hidden away in the closet
- SDA 2BTL · Sonicaps · Mills resistors · RDO-198s · New gaskets · H-nuts · Erse inductors · BH5 · Dynamat
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So I unplugged the cable that goes between the to speakers and now I have bass. It's not real tight bass but is full a and low. I think at this point I'm going to order the hardware to rebuild the crossovers. I have a question - I'm upgrading to the RD0198 tweeters in my SDA 2B's so can you do the same in the SDA SRS 2.3 speakers and if so what are the crossover changes that are need when doing this?
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Interesting but have you checked that all the polarities are correct on the MW's AND done the push test correctly as per above ^^^ on both.George / NJ
Polk 7B main speakers, std. mods+ (1979, orig owner)
Martin Logan Dynamo sub w/6ft 14awg Power Cord
Onkyo A-8017 integrated
Logitech Squeezebox Touch Streamer w/EDO applet
iFi nano iDSD DAC
iPurifier3
iDefender w/ iPower PS
Custom Steve Wilson 1m UPOCC Interconnect
iFi Mercury 0.5m OFHC continuous cast copper USB cable
Custom Ribbon Speaker Cables, 5ft long, 4N Copper, 14awg, ultra low inductance
Custom Vibration Isolation Speaker Stands and Sub Platform -
The polarity seem to be correct on both speaker. When pushing the Passive Radiator in quickly and holing it there it takes the 6.5" drivers about 5 to 6 seconds to return to there mid position.
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The dimensional speakers too? I would check the polarity of the interconnect cable and make sure it isn't wired incorrectly.George / NJ
Polk 7B main speakers, std. mods+ (1979, orig owner)
Martin Logan Dynamo sub w/6ft 14awg Power Cord
Onkyo A-8017 integrated
Logitech Squeezebox Touch Streamer w/EDO applet
iFi nano iDSD DAC
iPurifier3
iDefender w/ iPower PS
Custom Steve Wilson 1m UPOCC Interconnect
iFi Mercury 0.5m OFHC continuous cast copper USB cable
Custom Ribbon Speaker Cables, 5ft long, 4N Copper, 14awg, ultra low inductance
Custom Vibration Isolation Speaker Stands and Sub Platform -
Are these 2.3 or 2.3tl speakers?
Pictures would help. 2.3 cannot be tl'd. Plus you would need all new drivers to go from 2.3 to 2.3tl. two very different beasts...
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While I grant that he'd need to change a heap of components in the HF section of the crossover, I don't see any reason the three-tweeter array couldn't be upgraded to '198s.Are these 2.3 or 2.3tl speakers?
Pictures would help. 2.3 cannot be tl'd. Plus you would need all new drivers to go from 2.3 to 2.3tl. two very different beasts...
If you're replacing the six tweeters anyway, and re-capping the crossover, it wouldn't be all that much more work to just build the crossovers as if they were 2.3TLs. Some extra caps, some extra resistors, a few inductors. Especially if he were to do it on Gimpod boards.
Worst part would be potential level-matching between the "2.3TL" treble section and the "2.3" mid-bass section. Might have to play some games with resistors either in the treble or the bass. -
I guess I should have stated "easily" any hoots how is that 2.3tl crossover going to interact with all the different drivers 2.3 has?If you're replacing the six tweeters anyway, and re-capping the crossover, it wouldn't be all that much more work to just build the crossovers as if they were 2.3TLs. Some extra caps, some extra resistors, a few inductors. Especially if he were to do it on Gimpod boards.
Your left speaker becomes the right the right becomes the left?
At this point I guess with the outlaying of cash they're some dang fine other speakers out there for the kind of cash that is about to be plunked down.
Yes the RD-0198 is a very good tweeter BUT there's not a dang thing wrong with the RD-194 either. The 198 is not the be all end all in tweeters lets be honest. -
So I unplugged the cable that goes between the to speakers and now I have bass. It's not real tight bass but is full a and low. I think at this point I'm going to order the hardware to rebuild the crossovers. I have a question - I'm upgrading to the RD0198 tweeters in my SDA 2B's so can you do the same in the SDA SRS 2.3 speakers and if so what are the crossover changes that are need when doing this?
NO!Political Correctness'.........defined
"A doctrine fostered by a delusional, illogical minority and rabidly promoted by an unscrupulous mainstream media, which holds forth the proposition that it is entirely possible to pick up a t-u-r-d by the clean end."
President of Club Polk -
That's just another sign that something is not right with the polarity of the speakers or crossover cable. I believe when you unplugged the crossover cable it allowed the dimensional drivers to work together with the stereo drivers resulting in more bass. @westmassguy would know more about this than I do but I believe what I'm saying is correct. You should solve this problem before replacing parts.So I unplugged the cable that goes between the to speakers and now I have bass. It's not real tight bass but is full a and low.
- SDA 2BTL · Sonicaps · Mills resistors · RDO-198s · New gaskets · H-nuts · Erse inductors · BH5 · Dynamat
- Crossover upgrades by westmassguy
- Marantz 1504 AVR (front speaker pre-outs to Adcom 555)
- Adcom GFA-555 amp · Upgrades & speaker protection added by OldmanSRS
- Pioneer DV-610AV DVD/CD player
- SDA CRS+ · Hidden away in the closet
- SDA 2BTL · Sonicaps · Mills resistors · RDO-198s · New gaskets · H-nuts · Erse inductors · BH5 · Dynamat
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That's just another sign that something is not right with the polarity of the speakers or crossover cable. I believe when you unplugged the crossover cable it allowed the dimensional drivers to work together with the stereo drivers resulting in more bass. @westmassguy would know more about this than I do but I believe what I'm saying is correct. You should solve this problem before replacing parts.So I unplugged the cable that goes between the to speakers and now I have bass. It's not real tight bass but is full a and low.
I'm not sure about the 2.3's, but I know my 2a's have less bass with the interconnect cable disconnected. -
What is the pin out on the Crossover cable?
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Positive
Blade goes to ground if I'm correct -
George / NJ
Polk 7B main speakers, std. mods+ (1979, orig owner)
Martin Logan Dynamo sub w/6ft 14awg Power Cord
Onkyo A-8017 integrated
Logitech Squeezebox Touch Streamer w/EDO applet
iFi nano iDSD DAC
iPurifier3
iDefender w/ iPower PS
Custom Steve Wilson 1m UPOCC Interconnect
iFi Mercury 0.5m OFHC continuous cast copper USB cable
Custom Ribbon Speaker Cables, 5ft long, 4N Copper, 14awg, ultra low inductance
Custom Vibration Isolation Speaker Stands and Sub Platform -
Checking between the ends of the cable I have continuity between the pins but the blades are open. Shouldn't there be continuity between the blades too?
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Absolutely.George / NJ
Polk 7B main speakers, std. mods+ (1979, orig owner)
Martin Logan Dynamo sub w/6ft 14awg Power Cord
Onkyo A-8017 integrated
Logitech Squeezebox Touch Streamer w/EDO applet
iFi nano iDSD DAC
iPurifier3
iDefender w/ iPower PS
Custom Steve Wilson 1m UPOCC Interconnect
iFi Mercury 0.5m OFHC continuous cast copper USB cable
Custom Ribbon Speaker Cables, 5ft long, 4N Copper, 14awg, ultra low inductance
Custom Vibration Isolation Speaker Stands and Sub Platform -
So does that mean the cable is bad because I have two cables and they are both the same?
