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Post by jts410 on Nov 5, 2013 10:07:07 GMT -5
Hi all, long time owner / reader.....first time poster. I've got baby #3 on the way so will be losing my audio room and need to downsize the system to something that will work in my home office space, roughly 10'x13' with a desk that will now be shoved into the far back corner! I've tried my current system (see signature) in the room and the big Focal's are way too much.....actually overpowering to the point where I'm losing significant amounts of low frequencies which I KNOW they can crank out.
Anyhow, long story short I was considering a good pair of monitors and the Stealth 8's peaked my interest. Specifically because I already run this set-up fully-balanced from DAC through power amp (ok, the XPA-200 isn't truly fully balanced) so I have all the required cables. If I sell the Focals and my current speaker cables I should be able to actually put money back IN the bank for once, even after purchasing the 8's, power cables, stands etc.
Can anyone provide some additional info on the Stealth's amplifier design. I believe they are Class A/B fully-differential correct? As far as the combination input if I'm using balanced cables from the XSP-1 would this give me a "fully-balanced" signal through to the speakers?
Thanks in advance for any info!
J
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Post by garbulky on Nov 5, 2013 10:11:47 GMT -5
No it would not be "fully balanced".
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Post by jts410 on Nov 5, 2013 10:16:07 GMT -5
Ok, thanks. So basically from a signal perspective it would be the same as my current set-up running into the balanced inputs on the XPA-200.
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Post by garbulky on Nov 5, 2013 10:34:04 GMT -5
That's correct. Good luck with your decision and congrats on the baby  |
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Post by jts410 on Nov 5, 2013 10:41:00 GMT -5
Thanks! And thanks again for the quick reply. Just hit "place order" for the Stealth 8's and a pair of 2M power cables.......will drop a few notes about them somewhere on here after set-up (fwiw).
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KeithL
Administrator 
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Post by KeithL on Nov 5, 2013 15:34:00 GMT -5
Hmmmmm.... The amps in the Stealths are Class A/B, and they have fully differential balanced INPUTS, but the amplifiers themselves are not differential (speaker drivers are all differential by most definitions). So, yes, the setup would be fully BALANCED, but not fully differential. However, you should always remember that "being differential" is a means to an end. Balanced inputs and outputs serve a purpose because they help provide immunity from noise and hum being picked up by the connection (and they facilitate an overall differential setup). Building an amplifier fully differential (hopefully, and all else being equal) gives you better performance and lower distortion. In the case of a complete device like a Stealth monitor, the only thing to look at is the overall performance. The main factor there is that the amplifiers and other electronics in the Stealths are optimally matched to the drivers (and even the enclosure) to deliver a certain level of performance - and quite spectacular performance at that. You really should think of a Stealth monitor as "a black box" (with a true balanced differential input), and not worry about what's inside beyond how it actually performs. To answer your question, if you use a balanced cable, then you will have a "true" balanced connection to the Stealths (with the common mode noise rejection and other benefits that implies). Hi all, long time owner / reader.....first time poster. I've got baby #3 on the way so will be losing my audio room and need to downsize the system to something that will work in my home office space, roughly 10'x13' with a desk that will now be shoved into the far back corner! I've tried my current system (see signature) in the room and the big Focal's are way too much.....actually overpowering to the point where I'm losing significant amounts of low frequencies which I KNOW they can crank out. Anyhow, long story short I was considering a good pair of monitors and the Stealth 8's peaked my interest. Specifically because I already run this set-up fully-balanced from DAC through power amp (ok, the XPA-200 isn't truly fully balanced) so I have all the required cables. If I sell the Focals and my current speaker cables I should be able to actually put money back IN the bank for once, even after purchasing the 8's, power cables, stands etc. Can anyone provide some additional info on the Stealth's amplifier design. I believe they are Class A/B fully-differential correct? As far as the combination input if I'm using balanced cables from the XSP-1 would this give me a "fully-balanced" signal through to the speakers? Thanks in advance for any info! J |
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Post by garbulky on Nov 5, 2013 16:12:01 GMT -5
Hmmmmm.... The amps in the Stealths are Class A/B, and they have fully differential balanced INPUTS, but the amplifiers themselves are not differential (speaker drivers are all differential by most definitions). So, yes, the setup would be fully BALANCED, but not fully differential. However, you should always remember that "being differential" is a means to an end. Balanced inputs and outputs serve a purpose because they help provide immunity from noise and hum being picked up by the connection (and they facilitate an overall differential setup). Building an amplifier fully differential (hopefully, and all else being equal) gives you better performance and lower distortion. In the case of a complete device like a Stealth monitor, the only thing to look at is the overall performance. The main factor there is that the amplifiers and other electronics in the Stealths are optimally matched to the drivers (and even the enclosure) to deliver a certain level of performance - and quite spectacular performance at that. You really should think of a Stealth monitor as "a black box" (with a true balanced differential input), and not worry about what's inside beyond how it actually performs. To answer your question, if you use a balanced cable, then you will have a "true" balanced connection to the Stealths (with the common mode noise rejection and other benefits that implies). Hi all, long time owner / reader.....first time poster. I've got baby #3 on the way so will be losing my audio room and need to downsize the system to something that will work in my home office space, roughly 10'x13' with a desk that will now be shoved into the far back corner! I've tried my current system (see signature) in the room and the big Focal's are way too much.....actually overpowering to the point where I'm losing significant amounts of low frequencies which I KNOW they can crank out. Anyhow, long story short I was considering a good pair of monitors and the Stealth 8's peaked my interest. Specifically because I already run this set-up fully-balanced from DAC through power amp (ok, the XPA-200 isn't truly fully balanced) so I have all the required cables. If I sell the Focals and my current speaker cables I should be able to actually put money back IN the bank for once, even after purchasing the 8's, power cables, stands etc. Can anyone provide some additional info on the Stealth's amplifier design. I believe they are Class A/B fully-differential correct? As far as the combination input if I'm using balanced cables from the XSP-1 would this give me a "fully-balanced" signal through to the speakers? Thanks in advance for any info! J So to simplify. The amp is not balanced like the XPA-1 L, XPA-1 and XPR-1. Emotiva's word for that seems to be "quad-differential" It's more like am XPA-100 in the balanced/differntial nature. This is because they can be considered monoblocks - (more or less). Unless you want to get real technical about the tweeter amp and bass amp sharing a power supply etc. |
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KeithL
Administrator
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Post by KeithL on Nov 5, 2013 17:06:26 GMT -5
That is correct. Incidentally, these are not exactly "our terms" - the terms are well known technical terms (although the details of how they are used vary slightly). A FULLY DIFFERENTIAL PIECE OF EQUIPMENT has two equal channels which amplify (or otherwise process) equal and out of phase versions of the signal. When the term is used to describe a piece of audio equipment, a fully differential amplifier (like the XPA-1) has two entirely separate and identical amplifier modules; one amplifies the in-phase signal, the other amplifies an out-of-phase, but otherwise identical, version of that signal. Since the output works out to being the difference between those signals, the good audio adds together, and the distortion tends to cancel out - so you get lower distortion (and slightly lower noise). In a DAC, the DAC chip itself puts out a matched pair of in-phase and out-of-phase signals .... or two entirely separate DAC chips can be used to do this (the digital portion is not usually differential, because you get no benefit from doing it that way, but the analog portions are). A BALANCED CONNECTION is a connection BETWEEN two pieces of equipment that carries two equal and out of phase versions of the signal. The receiving piece of equipment subtracts the two signals, which gives it a "double strength" version of the intended audio signal, but causes the noise picked up along the way (which is common to both lines) to subtract, and so cancel out. You also need to use a balanced connection if you want the entire system to be "fully differential". A differential amplifier is a type of circuit design which has all sorts of benefits, and is widely used in many ways. Engineers like diff amps because they're relatively cheap and easy to make, very flexible, easy to design around, and tend to work and sound very well. A differential amplifier can be an IC, or can be built out of separate transistors, or even tubes: A single differential amplifier works very well as the basis of the input circuitry on an unbalanced input. A pair of differential amplifiers (which can be cross connected to make things even better), is often used for a balanced input to a non-differential amplifier. (You could call this "dual differential".) You can also make a balanced input using a single differential amplifier, but this has more limitations. (In theory you could even make a "differential amplifier" that didn't have a balanced input - exactly - and using non-differential amplifiers, and the amplifier as a whole would be differential, and balanced, but the input wouldn't be - but that would just be silly.) If you now take a fully differential amplifier, and use a dual differential input for EACH of the two modules that comprise it, the result can be called "quad differential". (It's a "dual dual differential amplifier"; these differential amplifiers can again be cross connected in certain ways to further reduce noise and distortion. Some people would say that dual dual differential inputs make a quad differential input; others prefer to only call it that if it has those extra cross-connections.)  Most people worry about all this way too much. A balanced connection is significant because it does often reduce noise issues. A differential amplifier (or other piece of equipment) is less important because the benefits of differential operation are relative. A bad differential amplifier could well perform - and sound - worse than a good non-differential one; ALL ELSE BEING EQUAL a differential amplifier is usually going to be better than a single-ended one - but all else is rarely if ever equal in real life  So, for example, our XPA-1 - which uses two amp modules in a differential configuration - has lower distortion and sounds better than our other amps that use the same amp module in a non-differential configuration. If you Google "differential amplifier" and "differential input", you will get a wide selection of all of this information - mixed together. Honestly, though, unless you're an engineer, all you're likely to get out of it all is a slight headache - and a craving for a beer (or even several)  Hmmmmm.... The amps in the Stealths are Class A/B, and they have fully differential balanced INPUTS, but the amplifiers themselves are not differential (speaker drivers are all differential by most definitions). So, yes, the setup would be fully BALANCED, but not fully differential. However, you should always remember that "being differential" is a means to an end. Balanced inputs and outputs serve a purpose because they help provide immunity from noise and hum being picked up by the connection (and they facilitate an overall differential setup). Building an amplifier fully differential (hopefully, and all else being equal) gives you better performance and lower distortion. In the case of a complete device like a Stealth monitor, the only thing to look at is the overall performance. The main factor there is that the amplifiers and other electronics in the Stealths are optimally matched to the drivers (and even the enclosure) to deliver a certain level of performance - and quite spectacular performance at that. You really should think of a Stealth monitor as "a black box" (with a true balanced differential input), and not worry about what's inside beyond how it actually performs. To answer your question, if you use a balanced cable, then you will have a "true" balanced connection to the Stealths (with the common mode noise rejection and other benefits that implies). So to simplify. The amp is not balanced like the XPA-1 L, XPA-1 and XPR-1. Emotiva's word for that seems to be "quad-differential" It's more like am XPA-100 in the balanced/differntial nature. This is because they can be considered monoblocks - (more or less). Unless you want to get real technical about the tweeter amp and bass amp sharing a power supply etc. |
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Post by GreenKiwi on Nov 5, 2013 17:20:49 GMT -5
@emokeithl One quick question... are the crossovers before or after the amps in the Stealth 6&8?
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Erwin.BE
Emo VIPs 
It's the room, stupid!
Posts: 2,263
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Post by Erwin.BE on Nov 5, 2013 18:24:37 GMT -5
Thank you Keith for this wonderful explanation - again. Now when will we see those awesome stealth 88? I need them... honestly.
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Post by GreenKiwi on Nov 5, 2013 20:10:44 GMT -5
Erwin.BE Are you going with Stealth's for your new HT setup? The 88's would be super cool.
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Post by jts410 on Nov 6, 2013 16:23:39 GMT -5
KeithL and Garbulky - thanks a ton for the additional info! Reading my first book on amplifier design now (bedtime reading) with hopes of dabbling in some DIY tube stuff in the basement one day. Good to hear that this would be a fully-balanced set-up as I was thinking more about the CMNR effect since I'll be running 3M of balanced cables basically right next to the power cables for the monitors.
Are there any guidlines about placement with the Stealth's? Right now I've just moved into an 11' x 13ft room with gear on the short wall. Current floorstanders are 36" out from the rear wall and 18" from the sides, listening position is 7' back leaving 2' behind my head to the wall. So I've got some room to either move the Stealth's out at bit if they like room to breathe or move my chair foward, or both. Maybe I'm making too much out of this but at least it will be fun to play around with it.
They arrive tomorrow (I love that Emo stuff gets to me in MD in two days!) so will post some eye-candy pics one everything is set up.
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Post by garbulky on Nov 6, 2013 16:32:30 GMT -5
KeithL and Garbulky - thanks a ton for the additional info! Reading my first book on amplifier design now (bedtime reading) with hopes of dabbling in some DIY tube stuff in the basement one day. Good to hear that this would be a fully-balanced set-up as I was thinking more about the CMNR effect since I'll be running 3M of balanced cables basically right next to the power cables for the monitors. Are there any guidlines about placement with the Stealth's? Right now I've just moved into an 11' x 13ft room with gear on the short wall. Current floorstanders are 36" out from the rear wall and 18" from the sides, listening position is 7' back leaving 2' behind my head to the wall. So I've got some room to either move the Stealth's out at bit if they like room to breathe or move my chair foward, or both. Maybe I'm making too much out of this but at least it will be fun to play around with it. They arrive tomorrow (I love that Emo stuff gets to me in MD in two days!) so will post some eye-candy pics one everything is set up. I think you may be confused. This is not "fully balanced" like the XPA-1's are. This has XLR inputs. THe input is balanced. But the bit where the amplifiers are in two sections (with the signal out of phase) to cancel out distortion as in fully balanced and fully differential is not the case. The XPA-1, XPR-1 and XPA-1 L's are the only amps in emo line up that do this and this is what people usually think of when you ask this question. I missed the exact wording (differntial vs balanced) but I think that's essentially what you are asking? Fully balanced and fully differential is expensive and is not what the speaker's amps have. |
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Erwin.BE
Emo VIPs
It's the room, stupid!
Posts: 2,263
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Post by Erwin.BE on Nov 6, 2013 16:35:43 GMT -5
Erwin.BE Are you going with Stealth's for your new HT setup? The 88's would be super cool. Yes! And stealth 8 for surrounds. |
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Post by jts410 on Nov 6, 2013 16:40:12 GMT -5
Right, I think I get that it's not two paths in the amplifiers like the XPA/XPR monos. I was more asking if by running the balanced cables from the XSP-1 am I going to get the full benefit from them (common-mode noise rejection, etc) or is the amp just going to treat them the same as if I was running a pair of single-ended cables?
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KeithL
Administrator
Posts: 9,962
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Post by KeithL on Nov 6, 2013 17:39:51 GMT -5
It is a real balanced connection - and you DO get the common mode noise rejection.  Right, I think I get that it's not two paths in the amplifiers like the XPA/XPR monos. I was more asking if by running the balanced cables from the XSP-1 am I going to get the full benefit from them (common-mode noise rejection, etc) or is the amp just going to treat them the same as if I was running a pair of single-ended cables? |
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KeithL
Administrator
Posts: 9,962
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Post by KeithL on Nov 6, 2013 17:48:21 GMT -5
Actually, he's asking about the common mode noise rejection he gets when running the signal leads next to power cables.... and that is only dependent on its being a true balanced connection (input)... The balanced input cancels out noise picked up by the wires; a fully differential AMPLIFIER cancels out some of the distortion produced in the amplifier itself. The Stealth 8's are pretty tolerant of positioning (and you can use the EQ switches to compensate for placement). I find that they usually sound best to me away from both the rear and side walls, about 2-1/2 to 3 feet off the ground, and toed in so they face the listening position. If anything, I might prefer my listening position to be a few feet further from that rear wall, or put something absorptive (like a tapestry) on it. (But then I'm not a fan of massive amounts of "ambience".) KeithL and Garbulky - thanks a ton for the additional info! Reading my first book on amplifier design now (bedtime reading) with hopes of dabbling in some DIY tube stuff in the basement one day. Good to hear that this would be a fully-balanced set-up as I was thinking more about the CMNR effect since I'll be running 3M of balanced cables basically right next to the power cables for the monitors. Are there any guidlines about placement with the Stealth's? Right now I've just moved into an 11' x 13ft room with gear on the short wall. Current floorstanders are 36" out from the rear wall and 18" from the sides, listening position is 7' back leaving 2' behind my head to the wall. So I've got some room to either move the Stealth's out at bit if they like room to breathe or move my chair foward, or both. Maybe I'm making too much out of this but at least it will be fun to play around with it. They arrive tomorrow (I love that Emo stuff gets to me in MD in two days!) so will post some eye-candy pics one everything is set up. I think you may be confused. This is not "fully balanced" like the XPA-1's are. This has XLR inputs. THe input is balanced. But the bit where the amplifiers are in two sections (with the signal out of phase) to cancel out distortion as in fully balanced and fully differential is not the case. The XPA-1, XPR-1 and XPA-1 L's are the only amps in emo line up that do this and this is what people usually think of when you ask this question. I missed the exact wording (differntial vs balanced) but I think that's essentially what you are asking? Fully balanced and fully differential is expensive and is not what the speaker's amps have. |
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Deleted
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Post by Deleted on Nov 6, 2013 21:16:57 GMT -5
Honestly, though, unless you're an engineer, all you're likely to get out of it all is a slight headache - and a craving for a beer (or even several) Well, I did begin university as an engineering/math major but had to change since I worked 30 per week to pay my tuition and had almost zero time to study. OK, so I do in fact have a slight headache after reading this thread. Do you think non-alcoholic beer will do the trick? Seriously, I think since Keith arrived at Emotiva I have only disagreed, in a small part, on only one of his posts. Not to get his head too big for that hat, but I know very few folks that I would describe as brilliant. Along with my wife's oncologist who graduated summa cum laude from Harvard medical school I would place Keith in the brilliant category based on his posts. I'm sure he is very humble and probably would prefer not to respond, but I feel it needs to be said. His clear, logical, technical writing at the Lounge is impeccable. Very impressive and professional. Very nice contribution by Garbulky too! BTW, I just finished reading the UMC-200 owner's manual also for the second time. Kudos to whomever wrote the owner's manual. It is so nice for a change to read a owner's manual written in such clear and concise terms. Years of reading poorly translated manual's from Nikon, Canon, Sony, Teac, etc. make Emo manuals like a breath of fresh air. PS: There seems to be a glitch in the quote another's post procedure. |
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Post by jts410 on Nov 7, 2013 9:22:58 GMT -5
Got it all now, thanks much for the good discussion on my first post!
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Post by deviate2112 on Nov 11, 2013 17:47:25 GMT -5
Hey, lets get back to the Stealth 88 question...Any word....I'm thinking of pulling the trigger on 3 Stealth 8's but if I knew the 88 was around the corner for a center I'd just buy two and wait for the 88...I'd be willing to be a test subject...you know...if I had to...
Mike
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Most people worry about all this way too much.
