Using REW to measure SDA SRS 1.2
dubseven
Posts: 16
Hi all!
New to this, so please bear with!
Just picked up some near mint SDA SRS 1.2s. Appear to be all original. Did a few measurements with REW using a calibrated mic - getting some weird results. I measured a single speaker, bi-amped, with the interconnect disconnected. Am I doing something wrong?
New to this, so please bear with!
Just picked up some near mint SDA SRS 1.2s. Appear to be all original. Did a few measurements with REW using a calibrated mic - getting some weird results. I measured a single speaker, bi-amped, with the interconnect disconnected. Am I doing something wrong?
Comments
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Yes, everything.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 -
Hey @dubseven welcome! Not familar with REW, but perhaps some folks here are. Hopefully they will be able to help.
First and foremost, post some pics and tell us about your setup. Speaker positioning for those babies is critical, as well as the listening position. Components are important too, as you'll need some power to drive those babies!
Not sure why your interconnect cable is disconnected, as that is key for the SDA's to work properly.
And bi-amping. Lot's of debate on that here. I suggest you start small, don't bi-amp for now. Just hook up one amp for both speakers, and go from there.
Welcome!Basement: Polk SDA SRS 1.2tl's, Cary SLP-05 Pre with ultimate upgrade,McIntosh MCD301 CD/SACD player, Northstar Designs Excelsio DAC, Cambridge 851N streamer, McIntosh MC300 Amp, Silnote Morpheus Ref2, Series2 Digital Cables, Silnote Morpheus Ref2 Series2 XLR's, Furman 15PFi Power Conditioner, Pangea Power Cables, MIT Shotgun S3 IC's, MIT Shotgun S1 Bi-Wire speaker cables
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Living Room: Peachtree Nova Integrated, Cambridge CXN v2 Streamer, Rotel RCD-1072 CD player, Furman 15PFi Power Conditioner, Polk RT265 In Wall Speakers, Polk DSW Pro 660wi sub
Garage #1: Cambridge Audio 640A Integrated Amp, Project Box-E BT Streamer, Polk Tsi200 Bookies, Douglas Speaker Cables, Shunyata Power Conditioner
Garage #2: Cambridge Audio EVO150 Integrated Amplifier, Polk L200's, Analysis Plus Silver Oval 2 Speaker Cables, IC's TBD. -
Don't be discouraged by F1Nut's reply. He is rude to everyone "new" on this forum (<5-10 years).
I agree with Verb that you need to find/ make the interconnect cable and not biamping till you get everything set up first.
Where did you set up the mic when you tested the speaker? While the drivers all look the same the crossover is complicated and many of them play at different ranges, phase , and volume. Same for the tweeters IIRC one is out of phase and the other 3 play with slightly different crossover points and volume. So you can't have the mic closer to one driver than the other. Back the mic off to your listening and play around with height.
Not sure why you are seeing the big hump at 60 HZ. Do you have a 60 cycle hum in your system?
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Nothing rude about my answer, he's doing everything wrong. End of story.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 -
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 -
Yep.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 -
Just because he didn't have the interconnect cable hooked up? Is that "everything"?
You can bi-amp SRS 1.2s so that shouldn't be the problem. -
Yes, everything.
Any chance you'd help point me in the right direction?Hey @dubseven welcome! Not familar with REW, but perhaps some folks here are. Hopefully they will be able to help.
First and foremost, post some pics and tell us about your setup. Speaker positioning for those babies is critical, as well as the listening position. Components are important too, as you'll need some power to drive those babies!
Not sure why your interconnect cable is disconnected, as that is key for the SDA's to work properly.
And bi-amping. Lot's of debate on that here. I suggest you start small, don't bi-amp for now. Just hook up one amp for both speakers, and go from there.
Welcome!
Hey thanks! SDA SRS 1.2, two Ashly FTX2000 amps, DriveRack to split the signal for now until I can get a better setup.
I have the interconnect cable, but was trying to measure a single speaker - perhaps this was the wrong approach? Do I need to measure them together?Don't be discouraged by F1Nut's reply. He is rude to everyone "new" on this forum (<5-10 years).
I agree with Verb that you need to find/ make the interconnect cable and not biamping till you get everything set up first.
Where did you set up the mic when you tested the speaker? While the drivers all look the same the crossover is complicated and many of them play at different ranges, phase , and volume. Same for the tweeters IIRC one is out of phase and the other 3 play with slightly different crossover points and volume. So you can't have the mic closer to one driver than the other. Back the mic off to your listening and play around with height.
Not sure why you are seeing the big hump at 60 HZ. Do you have a 60 cycle hum in your system?
I set it about 3-4 feet from the speaker, about half way up. I do have the interconect, should I be measuring both speakers at the same time? I don't recall any 60 cycle hum. -
Another note - with the interconnect cable hooked up, something just doesn't sound right with the speakers. Which is what prompted me to measure them and see what was up. Feels like there is a big hole in the mid range, and the highs are super weak.
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First issue, you're using pro gear, which has no business in home audio. These speakers should be driven with high quality electronics and the amp has to be common ground.
Testing one speaker as you are doing is pointless, especially with SDA's. The SDA drivers when driven in stereo play at half the volume of the stereo drivers. Without the cable connected the SDA drivers will only play below 150Hz.
You are not bi-amping unless you use active crossovers.Feels like there is a big hole in the mid range, and the highs are super weak.
Ok, the speakers have issues, which could be a multitude of reasons. Go to VR3's site and download the SDA troubleshooting guide. Lack of treble could indicate bad tweeters. You'll need to pull each one to test. Push in each mid-driver to see that they move. If not the magnet has shifted and locked the voice coil.
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 -
First issue, you're using pro gear, which has no business in home audio. These speakers should be driven with high quality electronics and the amp has to be common ground.
Testing one speaker as you are doing is pointless, especially with SDA's. The SDA drivers when driven in stereo play at half the volume of the stereo drivers. Without the cable connected the SDA drivers will only play below 150Hz.
You are not bi-amping unless you use active crossovers.Feels like there is a big hole in the mid range, and the highs are super weak.
Ok, the speakers have issues, which could be a multitude of reasons. Go to VR3's site and download the SDA troubleshooting guide. Lack of treble could indicate bad tweeters. You'll need to pull each one to test. Push in each mid-driver to see that they move. If not the magnet has shifted and locked the voice coil.
The manual specifically states how to bi-amp - is this not correct?
Mid range drivers feel fine, will check tweeters! Thanks! -
Yes, it shows two ways to bi-amp, the only one that is true bi-amping is the one with the active crossover.
Forget about that right now, get a high quality home audio stereo amplifier and pre amp after you figure out what's wrong with 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 -
May also have a bad poly switch- Not Tom ::::::: Any system can play Diana Krall. Only the best can play Limp Bizkit.
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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 -
Kind of sounds like that is what he is hearing
"Feels like there is a big hole in the mid range, and the highs are super weak"
Sounds muddy to me- Not Tom ::::::: Any system can play Diana Krall. Only the best can play Limp Bizkit. -
Don't fire truck around with them,bomb them out and listen to them until your deaf because they will out live you!.
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Hey @dubseven welcome! Not familar with REW, but perhaps some folks here are. Hopefully they will be able to help.
First and foremost, post some pics and tell us about your setup. Speaker positioning for those babies is critical, as well as the listening position. Components are important too, as you'll need some power to drive those babies!
Not sure why your interconnect cable is disconnected, as that is key for the SDA's to work properly.
And bi-amping. Lot's of debate on that here. I suggest you start small, don't bi-amp for now. Just hook up one amp for both speakers, and go from there.
Welcome!
I would assume to measure frequency response of one speaker specifically, he is running just one without the cable, to avoid any measuring issues or artifacts.
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I would assume to measure frequency response of one speaker specifically, he is running just one without the cable, to avoid any measuring issues or artifacts.
Yeah, that was the idea, albeit likely incorrect -
The problem with that is you have to a stereo pair to get both speakers to function correctly. Trying to measure just one speaker renders 4 of the mid-woofers inoperable, causing the passive to not function correctly and the non working drivers to also function passively.
Your measurements will be all over the place.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 -
Two things. The third tweeter from the top on both speakers appear to be dead - coincidence, or would something else cause both to be inop?
Second, new sweep with both speakers and interconnect hooked up, mic placed inbetween speakers about 8ft back.
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tweeters are progressive point source top full hot then get quieter going to the bottom.
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1) where's the mic relative to the loudspeakers?
2) what's the room like as an environment (e.g., size, shape, floor covering, windows? drapes? wall hangings? 'sound treatment'?)
A diagram may be the best way to address 1)
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Switched to single amp, re-measured. The 3rd tweeter definitely
dead in both. -
swap the tweeters around to see if its the resistor!
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swap the tweeters around to see if its the resistor!
Just pulled one out and checked resistance, its an open loop. -
Replace the tweeters to rdo 198's if the speakers are definitely 1.2 TL's(check rear serial number area) ,these will replace the sl3000 which are a silver looking dome version.The sl2000 "white with black cloth looking ctr"are replaced by the rdo 194's.If your speakers are not 1.2 "tl's" , i would think seriously think about moding them to take the 198's.
Replacing the tweeters is a nice positive upgrade
"mint condition", gratz and nice score. -
I dont believe they are TLs. The tweeters are SL2000s.
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Are they definately 1.2's or SDA SRS? check serial number,if thats missing,you'll have to check the drivers individually as the SDA SRS are a different animal to the 1.2's and tl's .
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They are SDA SRS 1.2.
8 mids, 4 tweeters each. -
I would just replace the blown tweets for now and listen while you look seriously into upgrading them in the future.There is plenty information on here to do some cheep upgrades like dynamiting the basket drivers and adding black hole 5 or another dampening product to rear inside cabinet behind the drivers.
Glueing the magnets so they never move in the future is a "must do".
The speakers must be sealed properly, pushing in gently on the radiator and holding in , the 8 drivers should slowly move back in and should only take about 3 seconds or more.
If this is not for you they will definately sell easy enough.
As they say in here "Welcome to the rabbit hole"
They are keepers
