Vintage HiFi Audio Forum
Audio Discussion => General Discussion => Topic started by: GraphicFX on July 11, 2014, 11:10:49 PM
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I'm considering purchasing polk SDA 2A's
Im currently running crown ps400's in mono for each of my mains
Polk's website states the following:
"If you're using separate mono amplifiers without a common ground, Polk's AI-1 interface is available separately to ensure a proper connection."
So my question is, Will these Polks work with the setup I currently have? or will i have to run one Crown in Stereo.
Thanx in advance
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It sure seems like you need the interface (I base that off what you just posted, I have no experience with those cabs).
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If I am understanding your setup correctly, you have these amps running as individual monaural amplifiers, yes?
In such case, there would be no common ground.
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If you are running them bridged,,you may be able to connect/strap the negative binding post(check with manufacturer first) otherwise you will need to run one in the stereo mode.I would first check with the manu.
Good luck,,keep us posted
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If you are running them bridged,,you may be able to connect/strap the negative binding post(check with manufacturer first) otherwise you will need to run one in the stereo mode.I would first check with the manu.
Good luck,,keep us posted
That's what I was thinking. (hoping) I have no problem running just one amp to power these Polks, but having 2 amps bridged mono at 560 watts each is just plain fun. (and great bragging rights to boot). I've been overdriving my sony ss-tl6's for about 6 months now with my current bridged mono setup with no problems. (the speaker rating is 150 watts)
I plan on picking these up tomorrow from a guy in canton OH. so any more input from you guys (and girl) will be surely welcome
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The Polks can be anywhere from 4 to 6 ohms. Most bridged amps are limited to 8 ohms. I would not recommend running them bridged. One of your Crown amps running in stereo should be fine for those Polks. Try that first.
I've owned SDAs for ten years. speaker placement in critical to get a good SDA effect. Ideally, place them at least 6 -8 ft. apart, 6 to 12 inches from the rear wall and 3 ft. or more from the sidewalls. The SDA 2As have lots of available tweaks to make them sound even better. Good luck!
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The 2A's are 4 ohm nominal and dip lower, so bridged amps are out of the question. The 2A's cannot use the AI-1 either.
but having 2 amps bridged mono at 560 watts each is just plain fun. (and great bragging rights to boot).
Bridging causes a higher noise floor and from amps that are not known for their sound quality to start with doesn't leave much to brag about.
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from amps that are not known for their sound quality to start with doesn't leave much to brag about.
Some of Crown's stuff is a bit ragged, but 400s are really nice sounding amps. Have you heard them?
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Was the 400 Crowns attempt to tap in to the home market?
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The PS 400 was the pro version, there was also a home version that had some name I can't remember and 400.
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Was the 400 Crowns attempt to tap in to the home market?
Yes and No.
Here is my take on it.
The PS 400 is the studio/theater version of the "powerline" series. which was intended for the audiophile market
The PS series specs out the same, with more protection circuitry and hookups for 1/4" jacks as well as conventional RCA's.
The PS Series was intended for permanent installations such as theaters, churches and stadiums. It's a probability that when you went to the movies in the late 90's, the great sound you heard was most likely, coming from a large bank of crown PS400's. Our very own three rivers stadium used them as well.
At lower listening levels, they sound average and a bit boring.
At higher levels, the come alive. at just below clipping, they maintain complete control and poise. Their sound to me is very neutral, while maintaining transparency and warmth.
Headroom? endless!
I loaned my PS-200 to a friend when he picked up his Polk sda 1c's from Matt. He used it until he purchased an Adcom GFA 545. The adcom seemed a bit more laid back with a subtle quietness that was hauntingly seductive. At higher levels, however, you could hear mild strain and a bit of harshness. Although still sounding good, It was no match for the PS-200. At lower registers, The crown kept true to form, delivering warmth, transparency and punch. Both are conservatively rated at 100wpc. but the crown seemed more at home at it's limit. just when the GFA 545 was running out of steam, the PS-200 was just coming in to itself.
The PS 200 specs in at 100 wpc (8 ohms)
The PS 400 specs in at 160 wpc (8 ohms)
I agree that at normal levels, a decent amp out performs these crowns. but when the volume goes way up, I'll take the crowns.
The PS-400 weighs in at 55 lbs. They can run at their max output for their entire life. Mine average over 20 years old. I currently have 4 of them.
These are audiophile grade amps. They are highly reviewed and sought after.
You have politely bashed my bose, for obvious reasons.
Come and listen to these Crowns, then voice your opinion.
Have a nice day fella's. I'm going today to pick up my (new to me) Polk SDA-1a's
Full review and pics to follow.
Cheers!
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Correction: I'm going today to pick up my (new to me) Polk SDA-2a's
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Use the PS400 everything will be fine. You should not bridge it with the Polk SDA speakers.
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Sounds like the Crown has one hell of a power supply.
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I've fallen in love with Matthew Polk
I want to have his children
Hooked up the SDA's to a single PS-400 as per all your recommendations.
I am moved.
Full evaluation and pics to follow.
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Congrats on the new Polks. As F1 stated bridged amps don't like low impedance speakers. I suspect your new found passion
comes from 2 things. Of course the Polks. And you've finally unbridged the Crowns. You probably don't remember but in one of your other
posts I commented on how most bridged amps just don't around as good....and I speak from my own personal observations too.
Every amp that I've ever bridged (not that I've owned that many, but a fair amount) just didn't sound as good. You have plenty of power in stereo mode. BTW....I love Crown as well. One of the few pro audio amps that does sound really nice. The JBL 62xx series was also a great
Set of pro amps. Endless headroom, solid bass, and just plain musical. And...if you unbridged your other Crowns you can assemble even more systems! Can't have enough systems running.!
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Some of Crown's stuff is a bit ragged, but 400s are really nice sounding amps. Have you heard them?
To the best of my gray cells, no. Judging from the ones that I have heard I've had no desire to hear another one. That said, I suppose every dog has his day. 8)
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Congrats on the new Polks. As F1 stated bridged amps don't like low impedance speakers. I suspect your new found passion
comes from 2 things. Of course the Polks. And you've finally unbridged the Crowns. You probably don't remember but in one of your other
posts I commented on how most bridged amps just don't around as good....and I speak from my own personal observations too.
Every amp that I've ever bridged (not that I've owned that many, but a fair amount) just didn't sound as good. You have plenty of power in stereo mode. BTW....I love Crown as well. One of the few pro audio amps that does sound really nice. The JBL 62xx series was also a great
Set of pro amps. Endless headroom, solid bass, and just plain musical. And...if you unbridged your other Crowns you can assemble even more systems! Can't have enough systems running.!
The PS-400 does sound better in stereo. So what to do with the spare amp? It will be doing duty driving my bedroom mains. (Optimus pro LX5's (linaeum tweets) replacing the PS-200, which will now be handling bedroom surround duty via a Hafler circuit, feeding Boston T930's I know my mains and surrounds should be reversed, but the T930's make great end tables beside my bed.
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I really enjoyed my venture into the SDA series, I had the SDA-1 the original modal. Really loved the SDA effect! I was only running 65wpc into them, but they were more than enough for me!
Just a bit big for my room, otherwise I'd still have them.
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So what to do with the spare amp?
Sell it along with the one that is currently hooked up and go for an upgrade!
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Just enjoy your new setup for a while. If you feel you need an upgrade you'll know it. If the music still moves you and you're still taping your foot to good tunes just enjoy it. I think you'll be just fine with the Crown.
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So what to do with the spare amp?
Put another system together for your garage or bedroom! O0