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Newbie and IRS Sigmas Don't Mix Well

Discussion in 'Infinity Loudspeakers' started by Brunt, May 25, 2018.

  1. Brunt

    Brunt New Member

    Messages:
    43
    Location:
    San Diego
    Hi everyone, longtime lurker first time poster here. Let me start off by saying that I'm pretty much a newbie at hi-fi in general. I've been reading around for a while but have very little real world experience with this stuff.

    Recently I found a deal I couldn't pass up for a pair of Infinity IRS Sigmas, which are a pretty big upgrade from my Kappa 6.1s. I currently have an Adcom GFA-555 on the lows and 545 on the mids/highs but these speakers feel like they need more.

    I have a few specific questions in mind, but any input with how to get the most out of these will be greatly appreciated, I want to give them the love and care they deserve, and I hope to have these as my primaries for a long time to come.

    1. What should I do to make sure that I never even come close to burning the EMITs/EMIMs out? I've heard they are incredibly fragile to both clipping and excessive power. Since they are rare and expensive, I really don't even want to get close to hurting them in the first place.

    2. How in the world do you position these things? My room is 14.5'x23' but I have to use it where they are on the longer wall because of a fireplace hearth being in the way. I've heard that they have to have some toe in, and also that any toe in destroys their soundstage. Overall I'm clueless on correctly positioning speakers.

    3. What would you say is the best way to get high quality audio out of a PC and into a pre-amp? My current pre has RCA inputs only, and my motherboard doesn't have S/PDIF out so I would need to buy a sound card, but have been reluctant because I don't know what is good or bad for hi-fi. I would very much prefer doing this to using a CD player as I have accumulated a large collection of FLAC, SACD, and BluRay audio files of hard to find or expensive albums over the years that I would love to be able to really appreciate.

    4. What kind of amp/preamp setup do you guys recommend striving for with these? My budget isn't huge so I would prefer to stay in the used market here but can go up to around $500/component. Hopefully that's enough for these monsters.

    5. How many of these things are there? Unfortunately the seller didn't have the original crossover plates with the serial numbers on them, and finding real info on these things on the web seems impossible.

    Thanks for the help, any info or opinion is wanted.
     

     

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  2. okeeteekid

    okeeteekid Well-Known Member

    Messages:
    825
    Location:
    Northern NJ
    Congrats! The Sigmas are a nice speaker.

    I've owned Ren 90's 80's Sigma's and Epsilon's, in my rooms they always sound better with 1/4th of an inch toe in just to get the image more tightly focused, they sound their best when they are at least 3 Ft away from the front of the woofer to the wall behind them and 2 to 3 feet away from the side walls.

    I only use 50 wpc class A on the top of my epsilons, if you know the limits of your amp and do not play them too loud the drivers will last a lifetime, if you want them to sound even better I would look to replace the adcom 545 with something better, If I remember correctly the 545 was not one of adcoms better sounding amps.

    Don't get a sound card, a USB Dac will sound waaaaay better, I would look into getting a used dac with USB inputs, I run a USB cable from my PC to the dac then RCA or XLR's cables back into my preamp, It sounds almost as good as my CD player but only very slightly less dynamic in a A and B compassion, I run spotify premium.

    Don't know the #'s of how many Sigma's were made but just because they were Infinity's top of the line IRS series speakers there were nowhere near as many made as their more affordable lines of speakers, I would say only a few hundred were made.
     
    Last edited: May 25, 2018
  3. Silentnet

    Silentnet AK Subscriber Subscriber

    Messages:
    759
    Location:
    Charleston, SC
    The 545 is a solid amp, but probably not up to task for what you're asking it to do.
     
  4. Brunt

    Brunt New Member

    Messages:
    43
    Location:
    San Diego
    What would you guys recommend for my high-mid amp? The guy I bought it from said Emotiva makes good cheap power, but as I said earlier I would rather delve into the used market to get more bang for my buck. I tried a Carver tfm-35 briefly with the highs, and it was different, but I wouldn't say it was better. Maybe smoother?

    Any brands or specific models I should be looking out for on craigslist or flea bay?
     
  5. Silentnet

    Silentnet AK Subscriber Subscriber

    Messages:
    759
    Location:
    Charleston, SC
    I... Generally don't like Carver designs. I'm biased.
     
  6. Brunt

    Brunt New Member

    Messages:
    43
    Location:
    San Diego
    What brand do you think would be a good fit?
     

     

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  7. damacman

    damacman Blown and Injected Subscriber

    Messages:
    8,442
    Location:
    Gilbert, AZ
    Is there something about the 545 that you don’t like?
     
  8. chef free

    chef free AK Subscriber Subscriber

    Messages:
    2,232
    Location:
    Hayward, Ca
    Congratulations on you purchase! Those are some fine speakers, for sure...
    Regarding your questions:
    1. The Sigma are rated for 500 watts, don't go over, don't turn underpowered (your GFA) amps loud and you'll be fine. If you turn it up but it doesn't get louder, BACK OFF! EMITs and EMIMs are not fragile.
    2. In your smallish room, the long wall is a great choice. Get them away from the walls but don't have them the same distance from the side walls and the back wall, it will emphasize one bass frequency. In your room farther from the sides would be best. Seating area against the back wall will give louder bass. Start with the speakers about as far apart from each other as your listening chair is from the speakers and with zero toe in. Then adjust distance between speakers and toe in by ear, listening for a sharp, well defined image. If you can point to each musician, you have it!
    3. Get a DAC, make it a good one because it really matters.
    4. There are many stable amps out there for $500 used. Yamaha, bigger GFA, like 585, if you like their sound, Carver, Levenson, etc.
    5. Not that many... :D
    .
     
  9. Silentnet

    Silentnet AK Subscriber Subscriber

    Messages:
    759
    Location:
    Charleston, SC
    What Levenson amp can you get for $500? Much less one good for 200+ wpc at 8 ohms?
     
  10. Brunt

    Brunt New Member

    Messages:
    43
    Location:
    San Diego
    The sigmas are 4 ohm iirc, if that changes what amps I should be looking for.

    I don't have a problem with the 545 in particular, its just that it seems from what I've read to be decidedly mid-tier. These speakers on the other hand look to be on the higher end of things. I'm always looking to improve my set up and don't want to hold anything back. Should I put the same power amp on the highs vs the lows or keep it lower power to be safe? I have a line on another clean 555 if that amp is both better quality than the 545 and it would be a good thing to keep the output the same. If getting a single higher quality amp would be preferable to bi-amping with a pair of Adcoms, let me know.
     
  11. Silentnet

    Silentnet AK Subscriber Subscriber

    Messages:
    759
    Location:
    Charleston, SC
    4 ohm nominal. Lower at certain frequencies. Make sure whatever you get is stable in to very low impedence loads.

    The 555 is a Nelson Pass design, albiet an older one. Not sure about the lower or higher models in the same range.) That says, it's certainly not junk.
     
    Last edited: May 25, 2018

     

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  12. geoff727

    geoff727 Well-Known Member

    Messages:
    701
    Location:
    Seattle, WA
    To answer your questions (all good ones), buy and read The Complete Guide to High-End Audio by Robert Harley. If you are serious about the hobby/music, you owe it to yourself to take advice & knowledge from industry experts.
    G~
     
  13. Brunt

    Brunt New Member

    Messages:
    43
    Location:
    San Diego
    Thank you for that, I've been looking for a good resource. I've been bouncing around a bunch of forums, looked into crossovers and such on parts-express.com and read some technical documentation so far. As you can plainly see I've still got a ways to go but it will be nice to actually have a consolidated resource to draw from. I'll order it today, hopefully it will help me better tune the wonderful speakers that I bought before I figured out how to work them.
     
  14. StimpyWan

    StimpyWan AK Subscriber Subscriber

    Messages:
    3,994
    Location:
    Blue Ridge Mountains!
    Used, an Aragon 4004, 8002 or 8008 should work well. New, a Crown XLS 1502 or 2002 pro amp, would pump a fair amount of decent power, for your budget too.
     
  15. geoff727

    geoff727 Well-Known Member

    Messages:
    701
    Location:
    Seattle, WA
    I hope you enjoy it. It contains a huge amount on info on the technical aspects of components, what all those specs mean and why they matter (and if they matter), how to select and buy components, how to determine what you need, etc. It's a great resource, and much more than "one man's experience" as was suggested.

    Another I highly recommend is Get Better Sound by Jim Smith, another veteran of the industry. Among other things, it is very helpful in its guidance on how to properly place speakers in a room in a way that takes all the guesswork out of it. It does not have to do with formulas or general rules, like the golden ratio or rule-of-thirds stuff that a lot of people use. It's based more on a specific process. I've used a combination of Jim's and the general procedure used by Wilson Audio, with great success...repeatedly which is important. Unfortunately, I have to stick all my components between the speakers due to outlet limitations, a general no-no for sound quality. That's one advantage of having a simpler system.

    Good luck!
    G~
     
  16. okeeteekid

    okeeteekid Well-Known Member

    Messages:
    825
    Location:
    Northern NJ
    The only adcom I would use on the highs is 5802, the 565 monos and the 585 stereo are good amps but have cap problems, I can tell you this... I have the adcom 555 and I also have a Forte that is 50 wpc of pure class A made by threshold, it kicks my adcoms A$$, it's not as powerful as the adcom but the soundstage is more 3d, imaging is better, instruments are placed better and vocals are way better, the Forte sounds more like a tube amp, I use the 555 for the woofers on my speakers
     

     

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  17. slimpikkins

    slimpikkins Super Member

    Messages:
    1,783
    Location:
    South East PA
    Wow, great speaker purchase, welcome and congratulations. The Adcoms are great amps imho in that room would be enough if you don’t push it to much with super bass heavy music. Your source, preamp and speaker placement will have far more effect on your sound than new amps. You could get another 555 and bridge them. It’s not hard, there’s a sswitch and connect them as per manual. Maybe just run them with one and forget the 545. It is like 340wpc at 4ohm continuess and much more than that at peaks. Sure there are far better amps but for $500 not so much maybe the 5500 which is a little newer and also a np design. (That’s the one I still own).
    I play records and cds so can’t help you with computers and dacs but I’d definitely spend money on that source (dac or whatever) and a good preamp (if it’s needed with the dac) and then see what you think.
    Lots of luck, try the other furoms on this sight like “dacs” ,“digital source” and “general audio” for some more options and opinions. The two books g mentioned above are very good, I own both of them.
    Jim
     
  18. 7.62

    7.62 Gearhead Subscriber

    Messages:
    1,556
    Location:
    Las Vegas
    Congrats here also ! I just can't help myself from saying a big old Krell KSA two fity ( my weak attempt at street lingo) would be righteous !

    If those were in my house I wouldn't attempt to hook anything up Adcom to them...nope. I'd wait it out.

    I agree with above on a budget, pro time with a trip to guitar center, Sam ash, fry's to have a look at some of the higher powered Crown amps that match whatever Infinity recommends for power. I feel safer that way and at least could run them safely until a really nice vintage type heavy hitter came along.

    Seriously nice score man no matter what you paid :thumbsup:
     
  19. Belvedere2

    Belvedere2 AK Subscriber Subscriber

    Messages:
    246
    Location:
    Massachusetts
    Amps depend on your budget. Think my Thresholds cost me 1500.
     
  20. Listnnthdark

    Listnnthdark Well-Known Member

    Messages:
    502
    Location:
    West Lebanon NH
    Congrats ! Nice Vertical move !
    (1. What should I do to make sure that I never even come close to burning the EMITs/EMIMs out? I've heard they are incredibly fragile to both clipping and excessive power. Since they are rare and expensive, I really don't even want to get close to hurting them in the first place )

    (( BE CAREFUL )) . The only time I have ever damaged a tweeter is not by intentionally turning up more volume than the tweeters can handle . It was because I inadveratntly had volume way up when switching sources . ( This happens when the " Brain " of the listener forgets that the track ended and then mashes on the volume for no apparent reason and the the hand "connected " to "brain" hits the "fm radio" button ).

    > Me :whip:< Myself

    I am totally clueless on all this Dac stuff ..Can someone please enlighten ? I get all my music via youtube or xbox . I plug into the headphone jack and then a $2.63 splitter goes to my receiver ..
    What I am missing .? Just like any other source if the recording sounds great it sounds great :music: ( with no dac ) .. When the recording sounds poor it sounds poor ( Does the dac make everything sound better .) Or What :idea:
     

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