SDA Bass Response
zingo
Posts: 11,258
A buddy and I were talking about passive radiators, and I mentioned to him that Polk had very successfully used them in their SDA line to lower the frequency output of those 6.5" woofers. Not exactly remembering the specs, I looked up the SRS 2 and Polk claims it goes down to 14Hz! With four 6.5" woofers and a 15" passive radiator, those numbers seem very optimistic, and not an actual 14hz +/- 3db. Is that true? I know the low frequency output is very good due to the design, but just how low does that speaker, or any of the larger SRS line actually go?
Post edited by zingo on
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I have the SRS 2, speakers, and the only time I use a sub is for the LFE channel when watching movies on bluray disks. For music the SRS II with that 15' woofer does a fine job! I can't say if they actually do perform to the specs you quoted, but they have plenty of the lower frequency oomph.Sunfire Theater Grand IV
Sunfire Cinema Grand Signature
SRS 2.1TL
SDA 2BTL's
CSiA6
FXiA4
FXiA6
SDA 2A's
Monitor 10A's
http://www.douglasconnection.com -
Srs 2, a solid 30 is more realisticPOLK SDA 2.3 TLS BOUGHT NEW IN 1990, Gimpod/Sonic Caps/Mills RDO-198
POLK CSI-A6 POLK MONITOR 70'S ONKYO TX NR-808 SONY CDP-333ES
PIONEER PL-510A SONY BDP S5100
POLK SDA 1C BOUGHT USED 2011,Gimpod/Sonic Caps/Mills RDO-194
ONKYO HT RC-360 SONY BDP S590 TECHNICS SL BD-1 -
Here is a quote I found on the Polk site, " The use of 8 small active drivers coupled to the large 15" sub-bass radiator results in extraordinarily tight, quick and three dimensional mid and upper bass combined with low and sub-bass capabilities which are staggering (clean output at 25 Hz exceeds 100db!) An elaborate bracing system is employed resulting in a remarkably rigid cabinet which virtually eliminates colorations due to panel resonances."
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The SDA 1C in room response is 20-18,000 +/- 4dB
http://www.polksda.com/sda1creview.shtml
http://www.polksda.com/srsreview.shtml
If you read the 2 articles it's not just about who can hit the lowest freq response. It's about linearity and low distortion.
H9"Appreciation of audio is a completely subjective human experience. Measurements can provide a measure of insight, but are no substitute for human judgment. Why are we looking to reduce a subjective experience to objective criteria anyway? The subtleties of music and audio reproduction are for those who appreciate it. Differentiation by numbers is for those who do not".--Nelson Pass Pass Labs XA25 | EE Avant Pre | EE Mini Max Supreme DAC | MIT Shotgun S1 | Pangea AC14SE MKII | Legend L600 | BlueSound Node 3 - Tubes add soul! -
Here are the specs on the Polk website for the SDA SRS 2.3TL:
Total Frequency Response 12Hz-26kHz
Upper -3dB Limit 25 kHz
Lower -3dB Limit 30 Hz
I wonder too what they produce at 12Hz. All I know is that they sound wonderful. -
They are a successful study in what a passive radiator can do, and they best the low frequencies of a lot of speakers who use active woofers or ported designs. Even the Definitive Technology super towers with active 15" subwoofer claim frequency responce similar to the SDAs, but I doubt it actually comes close. Maybe only a true transmission line can produce deeper and cleaner bass?
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I very much like the radiator "sound" as it's been called. As far as actual specs of the lower frequencies I suppose Polk could have exaggerated, who knows for sure? The only time I don't like the radiator is for music with extreme bass drum rolls, think Mike Portnoy here, they just can't keep up with the actual speed he is playing..., IMO of course...Remember, when you're running from something, you're running to something...-me
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If they aren't keeping up it's the amp, not the speakers.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 -
Conradicles wrote: »Here are the specs on the Polk website for the SDA SRS 2.3TL:
Total Frequency Response 12Hz-26kHz
Upper -3dB Limit 25 kHz
Lower -3dB Limit 30 Hz
I wonder too what they produce at 12Hz. All I know is that they sound wonderful.
+1 to that!____________________________________________________________
polkaudio Fully Modded SDA SRS 1.2TLs + Dreadnaught, LSiM706c, 4 X Polk Surrounds + 4 X ATMOS, SVS PB13 Ultra X 2, Pass Labs X1, Marantz 7704, Bob Carver Crimson Beauty 350 Tube Mono Blocks, Carver Sunfire Signature Cinema Grande 400x5, ADCOM GFA 7807, Panasonic UB420, Moon 380D DAC, EPSON Pro Cinema 6050 -
+1 Or your cabinets are not sealed air tight. If there's leakage, it will interfere with the "Fluid Coupling" between the drivers and Passive Radiator (air being the fluid). That's Polk's whole concept, small, fast woofers, fluid coupled to large, lightweight, and fast Passive Radiators. Just my opinion.If they aren't keeping up it's the amp, not the speakers.Home Theater/2 Channel:
Front: SDA-2ATL forum.polkaudio.com/discussion/143984/my-2as-finally-finished-almost/p1
Center: Custom Built forum.polkaudio.com/discussion/150760/my-center-channel-project/p1
Surrounds & Rears: Custom Built forum.polkaudio.com/discussion/151647/my-surround-project/p1
Sonicaps, Mills, RDO-194s-198s, Dynamat, Hurricane Nuts, Blackhole5
Pioneer Elite VSX-72TXV, Carver PM-600, SVS PB2-Plus Subwoofer
dhsspeakerservice.com/ -
The only time I don't like the radiator is for music with extreme bass drum rolls, think Mike Portnoy here, they just can't keep up with the actual speed he is playing..., IMO of course...
This is not true. You likely have a problem with your speakers(leakage, old crossovers etc.) or your amp is not capable of supplying the power the speakers are asking for, think transient response.
My 1.2TL's combined with my mono blocks can keep up with any drum attack you can think of, and do so with amazing accuracy.The Gear... Carver "Statement" Mono-blocks, Mcintosh C2300 Arcam AVR20, Oppo UDP-203 4K Blu-ray player, Sony XBR70x850B 4k, Polk Audio Legend L800 with height modules, L400 Center Channel Polk audio AB800 "in-wall" surrounds. Marantz MM7025 stereo amp. Simaudio Moon 680d DSD
“When once a Republic is corrupted, there is no possibility of remedying any of the growing evils but by removing the corruption and restoring its lost principles; every other correction is either useless or a new evil.”— Thomas Jefferson -
westmassguy wrote: »Or your cabinets are not sealed air tight. If there's leakage, it will interfere with the "Fluid Coupling" between the drivers and Passive Radiator (air being the fluid). That's Polk's whole concept, small, fast woofers, fluid coupled to large, lightweight, and fast Passive Radiators. Just my opinion.
Excellent point.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 -
I very much like the radiator "sound" as it's been called. As far as actual specs of the lower frequencies I suppose Polk could have exaggerated, who knows for sure? The only time I don't like the radiator is for music with extreme bass drum rolls, think Mike Portnoy here, they just can't keep up with the actual speed he is playing..., IMO of course...
Did you read the trade mag reviews I posted? No exaggeration there in those actual measured specs by an independent teamIf they aren't keeping up it's the amp, not the speakers.
Most likely the case. And or room/placement issues
What other speakers have you used the exact same electronics on, in the same room and found the SDA's to be "slow" when compared to other speakers side by side?"Appreciation of audio is a completely subjective human experience. Measurements can provide a measure of insight, but are no substitute for human judgment. Why are we looking to reduce a subjective experience to objective criteria anyway? The subtleties of music and audio reproduction are for those who appreciate it. Differentiation by numbers is for those who do not".--Nelson Pass Pass Labs XA25 | EE Avant Pre | EE Mini Max Supreme DAC | MIT Shotgun S1 | Pangea AC14SE MKII | Legend L600 | BlueSound Node 3 - Tubes add soul! -
Or your speakers or listening position is in a null.
The neat thing about passive radiators, below the radiator's FS, bass roll off is 12db per octave, opposed to a ported speaker's 24db per octave. Making it as easier match to room/boundary gain than a ported speaker. The only other way to achieve this is with a large sealed speaker with a Q/bass alignment of .5."He who fights with monsters should look to it that he himself does not become a monster. And when you gaze long into an abyss the abyss also gazes into you." Friedrich Nietzsche -
I very much like the radiator "sound" as it's been called. As far as actual specs of the lower frequencies I suppose Polk could have exaggerated, who knows for sure? The only time I don't like the radiator is for music with extreme bass drum rolls, think Mike Portnoy here, they just can't keep up with the actual speed he is playing..., IMO of course...
Mike Portnoy sounds JUST fine over here... -
+1 , I remember seeing ads for amps that were tested with numerous bass kick drum attacks. The test showed how the amp produced the first strike fine, but progressively deteriorated after that. Those big bass notes suck the life out of the amp, maybe because of the small size of the capacitors or transformer?nooshinjohn wrote: »This is not true. You likely have a problem with your speakers(leakage, old crossovers etc.) or your amp is not capable of supplying the power the speakers are asking for, think transient response.
My 1.2TL's combined with my mono blocks can keep up with any drum attack you can think of, and do so with amazing accuracy. -
Same exact set-up, in the same place, with the 8t's swapped in place of the SDA's. Same stuff I've had for years, B&K pre, 200.2 amp, NAD C542 CDP. You guys are probably right, I'm just hearing things that aren't there, or, in this case, are, maybe... I "thought" I heard the same thing with my 7's, even after the crossover mods and break-in, maybe?...Remember, when you're running from something, you're running to something...-me
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Polkie2009 wrote: »+1 , I remember seeing ads for amps that were tested with numerous bass kick drum attacks. The test showed how the amp produced the first strike fine, but progressively deteriorated after that. Those big bass notes suck the life out of the amp, maybe because of the small size of the capacitors or transformer?
An amp with large capacitors will tend to be slower than an amp with a lot of small capacitors because the large capacitors take longer to recharge.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 -
Damn, there are alot, practically too many, variables to audio. Since the B&K's tend to have large capacitors maybe that's the reason? Wow, talk about a science. I think I need several systems for different tastes in music. It's always been a dream of mine anyways. One room for classical, jazz, etc., one for hard hitting rock with lots of volume, one for, well, you get the idea. Maybe for hard hitting music I need to find an amp with lots of smaller capacitors. Anthem comes to mind and so does, shall I dare to say, Emotiva?Remember, when you're running from something, you're running to something...-me
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An amp with large capacitors will tend to be slower than an amp with a lot of small capacitors because the large capacitors take longer to recharge.
Excellent point Jesse, this explains a lot on why I see so many newer amps designed with rows of smaller caps. I'm guessing the higher the total__ microfarad(uF) rating , the better?:question: -
These will set those SDA's on fire.
I'm using the 1500 with my SDA2's. Lower noise floor, that the 1000. Phenomenal amp IMO.
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You will get better performance from an amp intended for home use over one meant for commercial venues.The Gear... Carver "Statement" Mono-blocks, Mcintosh C2300 Arcam AVR20, Oppo UDP-203 4K Blu-ray player, Sony XBR70x850B 4k, Polk Audio Legend L800 with height modules, L400 Center Channel Polk audio AB800 "in-wall" surrounds. Marantz MM7025 stereo amp. Simaudio Moon 680d DSD
“When once a Republic is corrupted, there is no possibility of remedying any of the growing evils but by removing the corruption and restoring its lost principles; every other correction is either useless or a new evil.”— Thomas Jefferson -
He's pulling our legs John, at least I hope he is.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 -
Or your speakers or listening position is in a null.
Good point.... sitting half way between the front and back walls of a room will cancel out some bass frequencies.
I ended up having to block the sliding door to the deck and passageway between rooms. The room looked awful but I couldn't deal with knowing I was not getting the best sound. I'm so happy I have an understanding girlfriend. I need to make some basstraps.
