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How many watts for 1.7's?

58.7.180.129

Hi,

I've been helping a friend put together his first system, on a budget. We've gone with the 1.7's and a Esoteric SA-50 SACD/DAC/PRE in one, and were going to go with a 2nd hand ML 332.

However, the one we tried appears to have been a 220V model, and didn't work well in Perth, where our voltage sometimes hits 250V.

Our only good High-End dealer looks after us well with Accuphase. So if we go for a safe, with warranty new amplifier, we can consider the P4100 and A35.

P4100, is 180 watts, Class AB into 4 ohms
A35, is 60 watts, Class A into 4 ohms

I run my Quad 2905 with a A45, and its heaps! Will this hold true with the maggies?

Daniel.

Follow Ups:

RE: How many watts for 1.7's? - pictureguy 19:37:33 10/07/10 (0)
The ASP module used in the W4S kilowatt monos will only do maximum power for 15 seconds and the RMS continuous power is much reduced.

Scroll down and see the power output and limits.

Disclaimer:: I do not know how much the modules are modified by W4S. If they add plenty of heatsink, some of these numbers will doubtless improve. The Zobel burning up defines the time limit for maximum power.

I suspect, but can't prove that the guys that run these don't burn 'em up like I'd expect. You'd hear about it, that's for sure. Also, I'd like to see some voltage readings of some of these mondo systems when at loud end of 'comfortable'.

My system with ASP500 modules rarely peaks above about 20VAC.
Too much is never enough
- http://www.icepower.bang-olufsen.com/files/solutions/icepowe (Open in New Window)
RE: How many watts for 1.7's? - ws 09:20:36 10/06/10 (0)
I am using a pair of Pass XA160.5 and also have a CAT JL2 Sig MKII, driving the 1.7.
The extra power from the XA does make a diff, but not as significant as some may imply about the power hungry Maggies.
I'd recommend a Bryston 4B SST2 - Mike K 12:02:50 10/02/10 (0)
It may be outside the budget, but your ears and your Maggies will thank
you. I've seen references to 1.7s being run by Bryston 28Bs, but I
think that's probably overkill.

Brystons are prefereable for Maggies for two reasons: high power output,
very high damping factor, and of course the 20 year warranty (reason #3).

I don't think you'll be sorry for spending the money. If your friend
can afford the SA50, he ought to be able to spring for the Brystons.

MK
In the old days Magnepan recomended......... - Don_C 18:10:01 10/01/10 (0)
75 to 250 watts per channel, into 8 ohms, for ALL their speakers.

IMO this holds true today, after all, ALL Magnepan speakers have about the same efficency!
RE: How many watts for 1.7's? - BigguyinATL 10:59:08 10/01/10 (0)
60 Watt Class A: class A Amps need to have well regulated power supplies - which means clipping point is not much higher than 3dB more that RMS rating. 60 Watts is 18dBWatts add 3dB for the clipping point gives you 21dB add 83dB for the loudspeaker sensitivity (104dB) Add 3dB for the other loudspeaker (107) take away 2dB for distance vs room gain (105). Now we have to make some assumptions... First is you don't want your Amplifier to Clip! Obviously, an audiophile says "Of Course!" Unfortunately, the momentary clipping of a signal doesn't alway product awful sound... only a "momentary bluring" of transients, or a little more "harshness" in an already distorted signal (like an overdriven vocal mic). Some amps worse than others... A SE Class A Amp can be awful as the signal recovers from dropping below lower voltage limit.

Ok so you don't want the amp to clip: 105dB is estimated the clipping point. Take away a minimum 15dB for crest factor of the signal (this will handle the majority of recordings) and take away an additional 5dB for a little signal headroom - this is the amount you usually crank the volume up to after you have been listening for a while (the amount you turn down the car stereo volume in the morning after wanting is higher after a day's work) That leave you with 85dB RMS music loudness level (about 1 power amplifier watt - on the average) which is pretty loud - a good typical listening level. If you like classical music dynamics - it probably won't do... and if you use your system for parties where the music is cranked so you have to be 1/3 meter away or closer for elevated conversation you will need a lot more power.

Three most important things in Audio reproduction: Keep the noise levels low, the power high and the room diffuse.
RE: How many watts for 1.7's? - thetintdoctor 06:52:24 09/30/10 (12)
Hey there:

Don't want to sound like a broken record, but I actively bi-amp my 1.5QR's with 350 watts/ch into the woofer panels, 350 w/ch into the tweeters using Crown class D amps. No tweeter fuse and they are crossed over at 500hz, 24 db/octave. My average listening level is 90-95db, louder on some peaks. I have a relatively large room- 14.5ft x 35ft x 8ft.

I have an old Levinson ML11 that is sweet and tight, and sounds fantastic- as long as I keep the peak volume below ~90db. Even though this amp is a high current design, and 'doubles down' to 100w/ch at 4 ohms it definitely 'runs out of steam' on the music I like. IME, Maggies like higher power to sound their best.

You will find basically two points of view:
1. Maggies need high power.
2. They don't.

Depending on your needs, both are correct. Just be absolutely sure that the amp in question will fill YOUR needs, in YOUR ROOM, with YOUR MUSIC! For me, low power, be it tube or solid-state does not cut it.

Throwing $$$ at the problem won't necessarily get you where you want to go, either. Some here get great results from expensive equipment, some don't. They are both right.

Finally, I agree whole-heartedly that the W4S and Emotiva stuff works well, as I have been fortunate enough to use or own each. I can also state that the NEW Crown Class D Powerdrive series with 24db/octave crossovers built in work very well. They are highly configurable and are also relatively inexpensive. They do have fans though, however quiet- and some don't want that. In my installation, it is not an issue.

This is a big question with many possible answers. Hopefully we can point you in the right direction for you and your friend.
- RE: How many watts for 1.7's? - simic 02:10:54 10/05/10 (11)
  your bypassed the passive crossover in the MG1.5 and went active using the crossover in the crown amps?
  - RE: How many watts for 1.7's? - thetintdoctor 17:42:17 10/07/10 (10)
    simic:
    
    Sorry I didn't see your post earlier. That's correct. You can use the internal x-over as HP, LP, or LP on ch1 & HP on ch2. The slope is a fixed 24db/oct, however. I'm still experimenting, but between 375hz and 500hz sounds very good. I realize the amps may not be optimum for 2-channel but they sound incredible for the money, and allowed me to try bi-amping.
    - RE: How many watts for 1.7's? - simic 23:24:30 10/07/10 (9)
      Which Crown amp are you using? xti series?
      
      Thought that amp can allow you to select different slopes...
      
      How did you bypass the internal passive crossover? Solder new wires between the binding post and the tabs connecting to the mylar wires?
      - RE: How many watts for 1.7's? - thetintdoctor 04:33:30 10/08/10 (8)
        
        In Reply to: RE: How many watts for 1.7's? posted by simic on October 07, 2010 at 23:24:30
        
        I'm using 2 of the new Class D XLS-1000 Drivecore Series. The x-over freq is adjustable, not the slope. The slope on these is 24db/oct, fixed. The XTI may allow you to change the slopes, I'm not sure.
        
        In regards to the wiring, I ran my speaker cables thru the holes where the wires would normally go, and soldered them directly to the input terminals on the panel itself. I used the little set screws that normally tighten the speaker wire to the terminal as strain relief, instead. Gently tightened against the wire's insulation they keep the wire from slipping backwards and pulling on the panel terminals. I see no reason why one couldn't go from the tabs on the inside of the speaker connectors, but I wanted to leave my original passive x-over untouched, so I just bypassed it altogether. :-)
        
        RE: How many watts for 1.7's? - simic 08:31:33 10/08/10 (7)
        
        In Reply to: RE: How many watts for 1.7's? posted by thetintdoctor on October 08, 2010 at 04:33:30
        
        did you have to cut the cloth (enlarge the hole) in order to see/have access to tabs going to the mylar wire?
        
        all the soldering work can be done by just unscrewing the plate that secures the binding post/fuse?
        
        hmmmm... i smell a mini project coming up. ;)
        
        RE: I smell a mini-project... - thetintdoctor 11:04:02 10/08/10 (6)
        
        In Reply to: RE: How many watts for 1.7's? posted by simic on October 08, 2010 at 08:31:33
        
        Well, on the 1.5 QRs the front speaker cloth is very easy to remove, as it's stretched between 2 plastic 'L' channels that in turn fit into a slot cut into the vertical stiles. Here is what mine look like:
        
        http://www.integracoustics.com/images/magnepan/mg15.jpg
        
        I wouldn't know about the way other's grille cloth "socks" are attached...
        
        BTW, I intend to re-configure the system such that I can experiment with 'Asymetric' x-over points. The internal x-overs (HP and LP) are locked to the same freq in the amp if you use the "x-over" mode to vertically bi-amp, which means if you pick 500hz, that is the LP freq on ch1 and the HP freq on ch2. I'll change it at some point to use one amp in stereo for the bass panels and one amp in stereo for the tweeters. This way you could choose say, 300hz LP on the bass amp, and 400hz HP on the tweeter amp. It'll be fun, anyway. If you try something like that, let me know!
        
        RE: I smell a mini-project... - simic 23:44:12 10/09/10 (5)
        
        In Reply to: RE: I smell a mini-project... posted by thetintdoctor on October 08, 2010 at 11:04:02
        
        to remove the front speaker cloth, i just need to remove the two side rails (secured by screws) and then i can remove the front cloth to access the crossover and tabs?
        
        I dont have to deal with 2 gazillion staples as mentioned by others?
        
        RE: I smell a mini-project... - esande 11:56:04 10/11/10 (0)
        
        In Reply to: RE: I smell a mini-project... posted by simic on October 09, 2010 at 23:44:12
        
        Maybe not a gazillion staples. About 40 on the top layer and about 40 on the bottom layer were all I had to deal with on my SMGas. It seems like a lot more than it actually is. Putting them back together wasn't all that big a deal. I used fewer staples. Maybe 20 on the bottom layer and the same on the top. Not really an issue with a good staple gun. It all goes together quite easily.
        
        RE: I smell a mini-project... - thetintdoctor 05:37:11 10/10/10 (3)
        
        In Reply to: RE: I smell a mini-project... posted by simic on October 09, 2010 at 23:44:12
        
        Which speakers do you have?
        
        On my 1.5QRs, there was no need to remove the stiles (side rails). The cloth was held in place by 2 long plastic strips that were press-fit into an appx 1/8" wide groove cut into the front of each stile. All I had to do was carefully pry the plastic strips out (the cloth was glued to the plastic strips) and off comes the grille cloth. There were no staples, as on my 1.6es. I do not know about others like MMG's,etc.
        
        RE: I smell a mini-project... - josh358 08:30:03 10/10/10 (0)
        
        In Reply to: RE: I smell a mini-project... posted by thetintdoctor on October 10, 2010 at 05:37:11
        
        MMG's and lots of others have socks that are stapled on the bottom and also covered by the side rails (if any) and the rear panel.
        
        RE: I smell a mini-project... - Simic 08:15:57 10/10/10 (1)
        
        In Reply to: RE: I smell a mini-project... posted by thetintdoctor on October 10, 2010 at 05:37:11
        
        I own the 1.5 for more than 10 years n never realized it's so easy to get the front cloth off. ;)
        
        always thought it's staple heaven from the guides posted here.
        
        I can feel a strip of something (plastic?) behind the cloth where it meets the front wood piece. U mean I can start prying from the top and it will pop out? Hmmmm....
        
        RE: I smell a mini-project... - thetintdoctor 17:19:51 10/10/10 (0)
        
        In Reply to: RE: I smell a mini-project... posted by Simic on October 10, 2010 at 08:15:57
        
        I only know that on mine there were no staples holding the front grille, only the 2 plastic pieces. Look at your spkrs from the top, and see if there is a plastic piece across the top holding the cloth on. It may be secured by 2 screws that go in thru the back... it's been so long since I dismantled mine I can't remember. just be careful if you try to take them apart. But as far as your comment, the plastic piece you are touching thru the grille cloth is a long, vertical plastic 'l' that fits into a channel cut into the stiles. I have the 1.6-style grille cloth that I ordered from Magnepan, and they're the ones who told me how to get the grille off. There may also be a plastic piece on the bottom- but the previous owner of my 1.5s had left it off, if there ever was one.
        
        I had a few minutes today to re-configure the system so the bass panels are driven from 1 amp, the tweeters from the other. The bass amp runs out of steam a little faster, but the change was worth it! I'm running 250hz LP and 500hz HP, both 24db/oct. The factory passive was 6db(just a series cap) for the tweet@2500hz, and 300hz, 12db for the bass panel. Things are really sounding great, but I'm getting the XLS2000 to run the bass panels now.
        
        Good Luck!
RE: How many watts for 1.7's? - morricab 06:35:13 09/30/10 (0)
The A35 might be a bit strapped if you listen loud and in a large room. That is partially because it will have a fair amount of negative feedback, which will make the clipping more abrupt than if it didn't. On the other hand it could have a fairly high dynamic headroom (a lot of smallish amps with big power supplies can get an extra 2-3db headroom).

If you listen at moderate levels or are in a smallish room then it will likely sound better than the Class AB amp from the same company. I heard the A50V and A60 models and they were quite good actually.
RE: How many watts for 1.7's? - ocezam 05:53:40 09/30/10 (3)
I go with either:

http://emotiva.com/xpa2.shtm

or two of these;

http://emotiva.com/xpa1.shtm

Brand new. 5 year TRANSFERABLE warranty. And they sound wonderful. I believe they both have auto voltage sensing. Mine is currently running on 230VAC.
- Emotiva is a good suggestion - SnaggS 03:25:22 10/01/10 (2)
  I hadn't seen these before, what a bargain, and the XPA-1's topology is nice as well.
  
  Daniel.
  - RE: Emotiva is a good suggestion - thetintdoctor 03:58:11 10/01/10 (1)
    Daniel:
    Glad you looked them up. as someone else posted here, Emotiva products do a nice job and have a great warranty. I am very happy with mine. Jeff.
    - RE: Emotiva is a good suggestion - ocezam 05:49:34 10/01/10 (0)
      You won't go wrong with Emotiva. Only thing they're missing is the snob factor. Pretty sure they'll cure your voltage problem also. As I said mine "auto sensed" an input change from 115 to 220 volts. Isn't this what started this thread?
Sorry, mate, no ... or, at least, it's extreeemely doubtful !! :-(( ... - andyr 01:10:40 09/30/10 (13)
Can you audition both those amps at home with the 1.7s? I would suspect that even the P4100 is not going to be able to deliver the kind of power that Maggies love.

How about something like 150w into 8 ohms and 300w into 4 (as a minimum)?? Some inmates here use 1Kw Class Ds!! :-))

Regards,

Andy
- Unfortunately not... my calcs are as follows - SnaggS 02:22:45 09/30/10 (12)
  Isn't the max power of the Maggies 250w into 8 ohms? Even the Accuphase P-7100 only does 125 watts into 8 ohms..is a 50kg beast, and getting seriously expensive!
  
  The calcs I have done are as follows
  
  At 3 metres from the 1.7's and adding 5db for room gain, and requiring 3db of headroom.. you need;
  
  New Age 60-70 dB <1 watt
  Chamber music, small auditorium 75 - 85dB 1 watts
  Folk 75-90 dB 3 watts
  Jazz 80-95 dB 8 watts
  Pop 90-95 dB 25 watts
  Symphonic Classical 75-120 dB 143 watts
  Rock 95-110 dB 254 watts
  Heavy Metal 110 dB 1426 watts
  Loud rock concert 115 dB 7149 watts
  Physical Pain 125 dB 45106 watts
  Death 180 dB 142637 watts
  
  Health guidelines say no more than 94db for one hour, or 36 watts.
  - 3dB headroom? - BigguyinATL 08:35:59 10/01/10 (0)
    Try minimum 13dB headroom! and that's just for rock and roll!
    Three most important things in Audio reproduction: Keep the noise levels low, the power high and the room diffuse.
  - RE: Unfortunately not... my calcs are as follows - josh358 10:33:17 09/30/10 (0)
    The amplifier power specs aren't really applicable, planars will eat several thousand peak watts and with acoustical music anyway that's going to be the limiting factor. What can damage them is high continuous power levels, at some point the mylar gets soft and wrinkles. But the 4A fuse will prevent that, it will blow at 64 watts continuous.
    
    The peak-to-average ratio of acoustical music is 10-20 dB. OK, so 120 dB is a pretty good peak figure for classical music with headroom. I'd aim for that, which means that if your priority is clean peaks at natural levels (not everyone's is), you should size your amplifier accordingly. If you want to do the calculations figure 83 dB at 1 meter at 1 watt, add maybe 4 dB for room gain (dipole line sources throw less energy into the room than omnis), subtract 6 dB for a 3 meter listening distance (line sources fall off linearly in the near field, rather than as the square). So you have about 80 dB for 1 watt. That means you need about 10,000 watts of peak power into 4 ohms. Now reality intrudes, and you go with 1000 watts RMS into 8 ohms and an amp that has reasonably good peak headroom (in most amps, more likely to be limited by current at 4 ohms than voltage), and sacrifice your 3 dB of headroom. In practice, that's usually enough, although one poster here, who likes to listen to chamber music at proximate levels, had to put a 2000 watt bass amplifier on his triamped system to eliminate clipping.
    
    You don't want the continuous levels of a rock/heavy metal concert because they'll damage your hearing over time, but in any case you're going to be limited on heavily compressed material by the 4A fuse and the thermal limits of the tweeter rather than the amplifier.
    
    Anyway, it's worth reiterating that whether you need an amp that large (or even larger) depends on your listening habits and, perhaps, whether you prefer the sound of a small sweet amplifier to the openness that a powerful amp can bring to the loudest recordings. As someone pointed out, it can also depend on the amplifier and amplifier technology, some handle overloads better than others.
  - RE: Unfortunately not... my calcs are as follows - neolith 06:11:01 09/30/10 (2)
    I run a total of 2200 W (550 @ 4 ohm) into my actively bi-amped (so 4 channels) IIIa's, and I rarely listen above 90db peak. Just sayin' :)
    �
    
    I plan to procrastinate my demise for as long as possible. In the meantime, I practice by putting off all the little stuff.
    - RE: Unfortunately not... my calcs are as follows - morricab 06:32:10 09/30/10 (1)
      "and I rarely listen above 90db peak. Just sayin' :)"
      
      And you also don't use more than a handful of those watts in that case.
      
      I have a friend with McIntosh MC501 monos and we are rarely above 5-10 watts in a listening session. Occasionally with some loud listening with more dynamic than usual music there were peaks to 50 watts. Just sayin'
      - can I play too? - wazoo 20:22:24 09/30/10 (0)
        
        In Reply to: RE: Unfortunately not... my calcs are as follows posted by morricab on September 30, 2010 at 06:32:10
        
        I have a pair of 3.6s driven by a single, but hefty Pass amp that happens to have something akin to a power meter on its face. To oversimplify a little, that X350 will pump 140W into a 4ohm load in class A mode - exceeding that point is indicated by the movement of the meter.
        Last Saturday, some friends asked me if I had any Eagles on DVD. We enjoyed near-live levels throughout the entire 2nd disc of The Eagles' Farewell 1 Tour (I rather like Joe Walsh). That needle never stopped moving.
        Just sayin'.
        ---
        BTW, everyone thought it was awesome. That volume revealed some niggling room issues, but that's going to take a little while longer to get nailed down. All in all, I pretty much agree with my friends' assessment of awesome. To be quite honest, that's the loudest I've ever listened to a stereo for that long - I never once thought about turning it down (except for this fear that I might be disturbing neighbors with midnight approaching). Obviously, nobody else thought about it either - I asked after a couple of songs and they wanted me to turn it up a little (it was already as loud as I would normally listen).
        Just sayin'.
        ---
        Okay, what exactly am I just sayin'?
        I can only say that I bear witness to the fact that Maggies have no compunction against cracking a whip on a brute's back. 700W is a far cry from 2200W, but it's still a fairly significant amount of power. If you want to crank them, you better have a big spoon ready.
        
        "Jazz is not dead - it just smells funny" FZ
        
        Edits: 09/30/10 09/30/10
  - Do all the calcs you want, mate - actual comparison of different amps ... - andyr 02:43:46 09/30/10 (6)
    is what is needed. It's not just the watt rating into 4 ohms or the amount of current which the amp can put out. It also depends whether its tube power or ss power. And other things. :-))
    
    It also depends, yes, on how loud you like to listen.
    
    But if you search these pages, you'll find post after post of people who are running what are humungous amounts of power into Maggies - and loving it (and not blowing them up, either!). And also posts by people with true-ribbon Maggies who have blown their ribbons by feeding the speaker with (in one example) a 100w tube amp (most likely due to clipping, which injects a lot of HF hash into the signal).
    
    The Accuphase P7100 may well be enough (as, being Accuphase, it probably has a pretty hefty PS!) but, as I said, some people are using 1Kw Wired4Sound D-class amps on their bass panels alone!
    
    Don't confuse $$$ cost with ability to drive Maggies. I have heard a Parasound A21 driving 3.6s very well - which requires more power than a 1.7 - and that is not anywhere near the same $ price bracket as Accuphase.
    
    Regards,
    
    Andy
    - RE: Do all the calcs you want, mate - actual comparison of different amps ... - morricab 06:29:59 09/30/10 (4)
      "But if you search these pages, you'll find post after post of people who are running what are humungous amounts of power into Maggies "
      
      You don't seriously think that they are using the full power of their amps 99.9% of the time do you? I would wager that most of the time the amount is in the single to low double digit range.
      - RE: Do all the calcs you want, mate - actual comparison of different amps ... - Davey 08:43:34 09/30/10 (3)
        
        In Reply to: RE: Do all the calcs you want, mate - actual comparison of different amps ... posted by morricab on September 30, 2010 at 06:29:59
        
        Brad,
        
        ".....most of the time the amount is in the single to low double digit range."
        I'd agree with that, but.....it's probably time for your canned (spl/distance/watts) reply again. :)
        
        I can't believe how convoluted these power/current discussions have gotten on this forum through the years. Andy is talking about the difference between tube and SS power......folks seem to equate power amplifier 'capability' with power 'usage'....
        
        Cheers,
        
        Dave.
        
        RE: Do all the calcs you want, mate - actual comparison of different amps ... - morricab 12:42:57 09/30/10 (2)
        
        In Reply to: RE: Do all the calcs you want, mate - actual comparison of different amps ... posted by Davey on September 30, 2010 at 08:43:34
        
        no its, the big blue meters said so.
        
        RE: Do all the calcs you want, mate - actual comparison of different amps ... - Travis 16:13:20 09/30/10 (1)
        
        In Reply to: RE: Do all the calcs you want, mate - actual comparison of different amps ... posted by morricab on September 30, 2010 at 12:42:57
        
        Oh no, it's the heat sinks you can't leave your hand on.
        
        "If people don't want to come, nothing will stop them" - Sol Hurok
        
        RE: Do all the calcs you want, mate - actual comparison of different amps ... - morricab 03:30:58 10/04/10 (0)
        
        In Reply to: RE: Do all the calcs you want, mate - actual comparison of different amps ... posted by Travis on September 30, 2010 at 16:13:20
        
        The big McIntosh MC501s run pretty cold actually as they are mostly Class B. We had the pair hooked up to a PS Audio power regenerator (just to see what would happen as it was only a 500 watter) and at idle the two amps together only were drawing 90 watts of power. That means each 500 watt monoblock is idling at only 45 watts of power draw, which means not much bias current running through them there output transistors (probably less than 1 watt Class A power available).
    - RE: Do all the calcs you want, mate - actual comparison of different amps ... - warmfires 02:50:58 09/30/10 (0)
      i'd agree with Andy here, i have a used NAD C270 power amp putting out 200w per channel and it isn't expensive, and it does a pretty good job of driving my MMGs.
      
      I auditioned a few amps..Quad 606, carver, both 100 watters and they couldn't do the job.
      
      WF.
      This rovers crossed over
      to the >>>SUNNY<<< side of the street

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