Same watts at 8 and 4 ohms?
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"Put it all together and you blew it once, and are blowing it again. Just not by as much this time"Well, life is a personal journey.... I will probably get into trouble for asking this, but what I want to know is what one hears with a 17 Hz bass response like the talons? How is that better than a speaker with a bass of 23 Hz? This is coming from the perspective that there is not that much recorded material able to provide 17 Hz. Maybe I am wrong in assuming that? |
n80 OP. John Curl design, it’ll be better than the Nad. Has ESS dac in it, also has phono stage if you ever need it, sub outputs and an active xover, HT bypass, it’s the Swiss Army knife of integrateds TMR Audio, good reputable retailer. They have make an offer, offer $1500? The legendary Parasound John Curl Halo JC1 monoblocks can drive anything, even Wilson Alexia without breaking a sweat. These JC Halo Hint and Hint 6 integrated, are from the same stable as the JC1 monoblocks. Cheers George |
Millercarbon, are your Talons for sale? The Talons went in a heartbeat. Well its hard for people to believe. They look at my system and it doesn’t look all that special. https://systems.audiogon.com/systems/8367 In fact most of what’s going on is far from obvious. Even when like Michael came over and I explained everything. Even like the guy who bought the Talons. Warned him before playing anything there is a lot going on they will not sound like this when you get them home. Doesn’t matter. Dude heard one song, he was sold. Never even tried to talk me down. And I had em priced way high to allow for that. I know this is hard for people to believe but the truth is its the mostly invisible tweaks that make this system punch way above its weight. Way above. Then on top of that he was so impressed he wound up buying cables and amp, some old gear I had been sitting on forever not even trying to sell. Altogether he darn near paid for the Moabs. Only downside was this all sold so fast I wound up with no music at all for almost two whole months! Next time I will be waiting for the Raven before selling the Melody! |
Hi @dsper My main speakers are Thiel CS5’s and we have talked on other threads about how they are a difficult load as they dip close to 2 ohms and 82 dbl sensitivity. There has also been associated discussion about how more power can mean more noise. In this regards, Pass’ point that the signal to noise in the first watt matters more than the 200th watt, and that high power amps skew their S/N ratings if measured only at full power is true. However it is not universally true that a bigger amp will have more noise at 1 watt. Just looked at the CS5 impedance curve. Wow. https://www.stereophile.com/content/thiel-cs5-loudspeaker-measurements-0 You definitely want a beefy solid state amp. It doesn’t have to have a lot of power, but doubling power from 8 to 4 to 2 Ohms will be recommended or the speaker will sound like the impedance curve. One brand you may not have thought of is Sander’s Sound. Their ESL and Magtech amps are the best there is when it comes to this particular feature. Best, E |
+1 for a tube integrated. But if you don’t want to deal with the quirks of a tube amp - more heat, tube replacement, etc, get either a Hegel integrated or Musical fidelity integrated. I’ve owned/own both and can highly recommend them. They both drive difficult loads and sound very enjoyable. I listen to my tube amp often, but the 2 SS amps mentioned come very close. |
@mt9894, one of my restrictions is that for these speakers to stay in the living room, the stuff driving them needs to be fairly small and discrete. The Classe' and Bryston (which I am selling for an estate) in there now are not making my wife very happy. And it wouldn't hurt that whatever I end up choosing has a nice design factor like the Peachtree stuff. She won't be excited about the spare look of the NAD but it would suffice in that department. |
n80 OP Should be a great amp for the 7T’s linear amp and dual power supply, 12 x bjt output transistors per channel. Don’t listen to anyone here keep what you’ve got with this Proceed, it’s will be a very good amp with the 7T’s. 250w-8ohm and said to be 500w-4ohms https://i.ytimg.com/vi/LgnrqKWmaoA/maxresdefault.jpg n80 OPThe 6T’s "could" be just as difficult to drive the only integrated with dac I can recommend is a used John Curl Parasound Halo "Hint" or a new "Hint 6" Both these have ESS Sabre dacs in them, but are normal size not mini or small https://parasound.com/hint.php Cheers George |
The Aerial speakers are not that hard to find an amp for, your criteria limits your choices but you should find something appropriate. If memory serves Crutchfield paid return shipping on a preamp I tried about a year and half ago. I hate doing returns but the with no B&M stores close I've resorted to it a couple of times. |
If you're ready to consider a serious setup - amp and not integrated - I would recommend the H2O Audio S250 Signature. Old school linear power supply, dual big transformers, B&O Class-D. Puts out 250/500W into 8/4-ohms. Handles 1-ohm Apogee Scintillas with ease. It will easily run any of your speakers. You can leave it on all day and it doesn't get warm. A solid piece of gear, I had it for a while with Scintillas and Duetta Signatures and it was a great match. Read a review or two and check it out... |
Every time a question like this comes up it reminds me what a good decision I made way back in the 1970’s to avoid hard to drive speakers with low sensitivity. It just makes life so much easier. Doesn’t hurt that every hard to drive low sensitivity speaker I ever heard never sounded that good to me. Maybe because they were never used with an amp that could make them sound good? That could be it. But whatever, who cares, not my problem! It was only much later on that I discovered tube watts and solid state watts are nowhere near the same. People can howl all they want, throw all the technical mumbo jumbo they want, when you hear 50 tube watts have more authority than 200 SS watts you have to admit all the words in the world can’t change the fact tubes just plain sound way more powerful than they measure. Put it all together and you blew it once, and are blowing it again. Just not by as much this time. But its no hallucination. If anything stands a chance of making those speakers sound good its a good tube amp. I drove Talon Khorus for 15 years with 50-60 watt tube amps, and they went a lot louder than you're talking. So you will probably be fine. |
Okay Guys, Not to steal the OP's thread but I have what I think is a similar question in the spirit of the thread. My main speakers are Thiel CS5's and we have talked on other threads about how they are a difficult load as they dip close to 2 ohms and 82 dbl sensitivity. There has also been associated discussion about how more power can mean more noise. I have been thinking about the idea of less power creating less distortion and the ability to hear more detail. Assuming my last sentence has some validity, and wanting to try something a bit different, I am taking delivery on a pair of speakers rated at 8 ohms and 88 dbl sensitivity that I do not believe dip below 6 ohms. I probably do not listen to most music louder than say 91 dbl at about 9 feet. So... what watts do I need to be happy with a good tube amp? I have been hallucinating that a tube amp with a good 25 watts into 8 ohms and that holds 25 watts into 4 ohms should work quite well as a place to start. Am I anywhere near to correct about this? What else should I consider? My apologies to the OP if I am too off topic here. Thanks for listening, Dsper |
The distortion vs. output profile is a little more complicated than explained earlier. Please see figures 5 and 7 for what a very well behaved linear amp’s output usually looks like vs. output power. https://www.stereophile.com/content/luxman-l-509x-integrated-amplifier-measurements The limiting factor is often notch or crossover distortion, which is constant and occurs near zero output. As the output rises this distortion becomes a smaller proportion. Of course, eventually the amplifier will clip and distortion is dominated by the top of the waveform being flattened as the voltage at the output reaches the voltage of the power rails. Of course I am a Luxman fanboy but this curve is very common. |
If your amp puts out 150 watts into 8 ohms and 200 into 4 ohms, it will drive your speakers just fine if you only need 100 watts into the 4 ohm frequencies to drive them as loud as you want to listen to them.It is- and more to the point, in this example above, even though the amp doesn't double power **at full power** into 4 ohms, we can easily see that it does increase. If this amp has feedback, its output impedance will be low enough to enable it to act as a voltage source- all the way up to its rated power into 4 ohms. So what if that isn't double the power of the 8 ohm rating?? We are only talking about the amp at full power. At any other power level it will be just fine, meaning that it will indeed double power as the load impedance is halved. This holds true for impedances of less than 4 ohms too- but one must be increasingly aware of the limitations of the amp when coupled to such loads. As long as the load is easy to drive (such as Wilson speakers, which are easy despite their low impedance in the bass) it won't be an issue. Now someone touched on a different issue- that lower impedance loads cause amps to make more distortion. This is true, and is why you really don't want to make an amplifier (especially a solid state amp) work hard for a living! When it makes more distortion, especially if solid state, most of that will be higher ordered harmonics and IM distortion, both to which the ear has a keen sensitivity! IOW if **high quality audio** is your goal, regardless of your amplifier, a higher impedance load will do better justice to your amplifier investment. OTOH if **sound pressure** is your goal, you have that slight 3dB increase in volume if your speaker is half the impedance. IME the latter isn't worth it, but I like the stereo to sound nice :) |
djones51 -- You're the first to mention McIntosh autoformers which raises a question I've been puzzling over... I have a wonderful pair of Magnepan 1.7 that sounded great when I reviewed them through the sellers McIntosh tube amp, (I'm not sure of the power). Bringing it home and hooking it up with my Peachtree Nova Pre and 220 (class D) amp, it sounds very good but not as great in my recollection. Of course room size and positioning come into play but now I'm wondering if I'd get better performance by upgrading to a McIntosh or other high powered (AB) amp. |
Most amps you've mentioned are class D so George will do what he does bash class D using a Behringer PA amp as his usual suspect for all class D. If you want boat anchors you're all set but with your criteria of placement and price most small discrete integrated amps will be class D. There are a few AB the Micromega M100 is class AB in a small package as well as a few others. The NAD C388 should work fine with your speakers. The little 316Bee you mentioned measures 4 and 8 Ohm the same, it's the way they use their power supply with the modified Ncore amps. McIntosh uses autoformers on some integrateds they measure the same watts into 2,4,and 8 Ohms. George won't like the McIntosh either. Here's specs on the 316Bee notice the same 40w at 4 and 8 Ohm.
<0.03 % (250 mW to 40 W, 8 ohms and 4 ohms)
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George, the amp I was referring to is the Proceed HPA2. It is functioning fine and is in my primary system with an AR tube pre and Areial Acoustics 7B speakers. I'm keeping all of that as long as it keeps running. The 6Ts are for a secondary system in my living room, primarily casual listening. The reason I'm looking for an integrated with DAC is that it all needs to be as small and discrete as possible to make my wife happy and integrate with Sonos Connect (so coax or optical-in are important). |
While it is true that 'speaker sensitivity plays a role in required amplifier power, it is also true that amplifier power capability plays a role in distortion. An amplifier will exhibit lower distortion at low output levels than at high output levels. Distortion will often rapidly increase as the amp's rated power is approached. Linearity is usually much better at small signal levels, hence lower distortion. This means that at a given output power level, well-designed high-power amplifiers typically exhibit lower distortion than lower-powered ones. I run two channels of four Harmon Kardon Citation II tube amps each that, on the bench, deliver over 500 watts/channel with 0.05% THD at 1 kHz if line voltage is held at 120VAC. This means at normal listening levels, each amp is operating at or close to small-signal operation. Since the 'speakers driven by these amps are B&W 802Ds, I am glad I have the high-power capability. Normally, solid state amps will deliver twice the power to 4-ohm than to 8-ohm loads. However, power supply limitations can limit 4-ohm output. Tube amps generally deliver the same power at 4- or 8-ohms provided the secondary winding of the output transformer has a tap to match the 'speaker's impedance. By the way, at age 77, it is getting to be a big burden to carry a 60-pound tube amp from the first-floor listening room to the second floor test bench every time I have to change a tube. I do so because I set the output tube balance for lowest THD. If anyone wants to make an offer for 10 Citation IIs (I have four spares but want to keep a pair for other use), please let me know. Norm |
@georgehifi, Get an amp like I said for your Aerial 7T’s and you’ll be happy. Your 7T at 84db and 4ohm "nominal" you need 100w-8ohm and close to 200w into 4ohms because you can bet they dive to 3ohm or less with epdr somewhere.The OP's new speakers are Aerial 6T’s; manufacturer’s specs are 90dB sens, 4 ohm nominal with a 3 ohm low. I couldn’t find independent testing or impedance curve. So, possibly sensitivity could be 88-89 dB. The amps being considered could drive these speakers. |
The NAD C388 will drive your speakers just fine if you don't play your music at rock concert levels. But since you own/like a Levinson amp, which I think are all Class A/B, the NAD's Class D module may not make your speakers sing a tune you like. Safer to buy a Class A/B amp like the Cambridge CXA81 (which has a decent DAC), which is 80/140 watts into 8/4 ohms, and is within your budget. I have heard that amp make a pair of Monitor Audio Gold 100 5Gs sing, which are only 86 db sensitive and dip at various points under 4 ohms. |
n80 OP Get an amp like I said for your Aerial 7T's and you'll be happy. Your 7T at 84db and 4ohm "nominal" you need 100w-8ohm and close to 200w into 4ohms because you can bet they dive to 3ohm or less with epdr somewhere. From Keith Howards Measurement Labs https://ibb.co/7JrRXX8 This is the Wilson Alexia 90db and Wilson spec 4ohm nominal. You would think that just about any amp could drive it. But no. The Wilson Alexia is said to be one of the hardest speakers ever to drive. And that because just in a small band of the low to mid bass it has an EPDR (combination of low impedance and high - phase angle) which to the amplifier seems like .9ohm!! and it sucks the life out of an amp. And a 3000watt Behringer amp won't do it justice, but 25w ML2 will, to a certain volume level because they can double down to 1ohm, , it's all about the current, being able to double wattage 8ohm to 4ohm and 4ohm to 2ohm if you can do it for speakers like the Alexia and there are many like it. Cheers George |
Hi George, Take a look at any speaker review on Stereophile and they will plot the speaker impedance. This impedance is never a flat line at 4 or 8 Ohms and in fact take quite complicated shapes. The lower the impedance, the more current the amp has to produce to maintain a stable output, otherwise it starts to drop. If you think of a wall wart, 12V, 2 Amps. If you try to draw more than 2 amps, it no longer produces 12 V but instead the voltage sags until it overheats. Amps do the same thing. An ideal amp maintains the voltage output regardless of speaker impedance, which is synonymous with saying it doubles the wattage as the impedance is cut in half. You may not need an ideal amp or like how it sounds matched to your speakers though, so keep this in mind. The C 388 uses a hybrid Class D designed by Bruno Putzeys (or nCore?) which is a pretty sweet little thing. It puts a linear amp in the middle of the Class D. I have another NAD integrated with it and I like the sound a lot. It's not as fun to listen to as my Luxman, but nothing wrong with it either. |
By tested do you mean what the manufacturer will publish (some don’t give 4 ohm numbers) or do I need to look for an independent test?Test is to me an independent "test" like Stereophile, Soundstage Measurments, Miller Audio Research etc etc. As amp manufacturers "specs" sometimes/mostly fudge their specs. If they don’t give the 4ohm wattage numbers, then either the amp doesn’t look good doing them(like the heading of the thread) or goes backwards even from the 8ohm, or it simply can’t handle it at all, and turns off or blows a fuse. Look for reviews that give bench test also Cheers George |
n80 OP I’m not saying to get the ML2’s, it was used as an example of what does drive speakers. Your 7B’s drop to 3ohms around 150-200hz not too bad but still needs needs a bit of power there. But! they are specified as 86db by Aerial, but actually tested by Stereophile at only 84db!! I would look for a >100w-8ohm amp that can do tested doubling those watts into 4ohms and you should be fine. Or you can get the $400 3000w Behringer and listen to that, probally not for long.👎 Cheers George |
Your speakers don't look like they would be difficult to drive. They only reccomend and amp of 50 watts or higher. I haven't seen measurements of the 6t but stereophile has the 7t looks like it stays mostly between 4 and 8 Ohms. Frequency Response 35 Hz to 25 kHz ±2 dB, -6 dB at 30 Hz Sensitivity 90 dB for 2.83 volts at 1 meter on axis Impedance 4 ohms, 3 ohms minimum, low reactance Power Requirements 25 watts minimum, >50 recommended Woofers Dual 5.9″ (150 mm) with cast magnesium frames, special papyrus blend cone. copper pole sleeve, dual magnets, 1.25″ coil, long and linear Xmax Midrange 4.8″ (123 mm) with cast magnesium frame, special papyrus blend cone. copper pole sleeve, dual magnets, 1.00″ copper clad aluminum coil Tweeter 1″ (25 mm) with thick machined aluminum plate, soft ring-dome design with machined wave guide, dual-magnets, 1.00″ coil, copper pole sleeve Crossover Fourth order acoustic Linkwitz-Riley, 600 Hz and 4,000 Hz crossover frequencies, 2 physically separate networks |
You guys are teaching me a lot but not making it any easier. I'm just waiting for the magic word on the perfect $2000 integrated to match with a pair of $6000 speakers. ;-) @twoleftears I think those have been recommended but I can't remember if I have checked them out. But I will. @tomcy6 These speakers will rarely be played at more than 50% volume if that. @georgehifi I have a Levinson, well, Madrigal, dual monaural amp for my Aerial 7Bs and it is huge and heavy. No way the wife is going to allow a pair of monoblocks in there. She can't wait for me to get the Classe' and the Bryston out. |
n80 But I’m seeing a number of respectable mid-fi integrateds with the same wpc for both 8 and 4 ohms.Severely current limited either on purpose for damage protection (maybe by autoformer) and/or by bad design, these amps are not ideal to have with 4ohm nominal or less speakers Because 4ohm nominal speakers can go down even lower than 4ohms, maybe 2ohm, and even lower again as seen by the amp if there is >-50 negative phase angle involved at those low impedance’s. Good place to learn, study Stereophiles speaker bench testing, usually the first 3 or so paragraphs with graphs will give you far better insight than just words do here. Classic example is the 90db efficient Wilson Alexia, which is manufacturer spec’d at 4ohm nominal, yet tests show it goes down to 1.6ohm in the bass and has some -45 degrees phase angle which they say calculates to and presents as 0.9ohm! EPDR (equivalent peak dissipation resistance) as seen by the amp in that bass area. This is heavy reading 3 pages, so skip it if you want. https://www.stereophile.com/content/heavy-load-how-loudspeakers-torture-amplifiers-page-2 If watts is all that matters with no current ability, we all own these 3000w $400 Class-D Behringers, and we wouldn’t need an "Amplifier" forum section in Audiogon https://www.storedj.com.au/behringer-nx3000-ultra-lightweight-3000w-class-d-power-amplifier These 25w yess!! just 25w ML2 Mark Levinson monoblocks would slay the 3000w Behringer into the Wilson Alexia’s to a given level. https://www.hifido.co.jp/photo/05/504/50446/c.jpg https://img.usaudiomart.com/uploads/large/2229202-mark-levinson-ml2.jpg Cheers George |
I think that what Ralph is saying is that doubling power into 4 ohms is only necessary if you drive the amp to its full output. If your amp puts out 150 watts into 8 ohms and 200 into 4 ohms, it will drive your speakers just fine if you only need 100 watts into the 4 ohm frequencies to drive them as loud as you want to listen to them. Is that right, @atmasphere ? Playing your speakers (and most speakers) with 100 watts into 4 ohms would be really loud. I think any of the amps you're looking at will drive your speakers satisfactorily. So, as Ralph said, try to listen to the amps and pick the one that sounds the best to you. |
Thanks djones51. I should also mention that these will rarely if ever be used at high volumes and in fact I would put more of a premium on low volume listening in this room. I have an NAD C316BEE down at my cabin and it sounds really good for the price. That Guttenberg guys says the 316 is his 'reference' budget amp for whatever that is worth. Anyway, I guess it may just come down to trial and error, order and return but I do hope to narrow it down to two or three. I don't think the Cambridge has a DAC, which I am looking for. The NAD does have a DAC. I might start with the NAD. Also considering a Peachtree Audio Nova300 and remote possibility of a used Gato DIA 250. Some reservations about the Gato in that it is well over my preferred budget and I wonder about the possibility of service if needed. |
Have you looked at the Rogue Sphinx v3? Have you checked out Vincent integrated models? 90 is above average; 4 dropping to 3 is a bit below average. Poorly engineered amps will be uncomfortable with that impedance. If you deal with Crutchfield, Audio Advisor, Music Direct, and no doubt others, you'll have a generous audition period. |
@millercarbon, I get what you're saying but I have to narrow down the field somehow. And with a budget of under $2000 and no dealers conveniently close, auditioning is nearly impossible outside of shipping stuff back and forth which is time consuming and possibly expensive. I can tell you that they sound great with a Classe' Sigma SST pre into a Bryston 9B (both are AV units). But those are not mine to keep and they are too bulky and 'ugly' for the room. |
Its only mind-numbing if you make it that way. Most of the guys here are experts at spinning you so far down the rabbit holes you'll wish you'd taken up something fun and easy like nuclear physics or MMA. Your speakers are at the low end of acceptable, but then so were mine until recently. Here's what I had, and they were the same 90dB only mine were nominal 8 ohm. https://systems.audiogon.com/systems/8367 Notice that is a 50wpc tube amp. Notice that is a pretty big room. I listen fairly loud, sometimes really loud, and was just able to do that with these speakers and amp. Now with Tekton Moab speakers, 98dB, in spite of being 4 ohms they are a lot easier to drive and play really loud with a fraction of the power the Talons required. Because, remember, log function. So again, forget power. Forget who likes what. Least useful thing imaginable is some reviewer telling you they liked it. Only way that has any meaning at all is if you know the reviewer, he's your best bud, you heard all kinds of stuff together and agree on everything. Otherwise, ignore. Only thing matters is what they say they heard. Pay attention to how they describe the sound. How they say it compares to other amps. Pay attention to what they regard as a higher standard. Because its all relative. There's a million levels. You can find great gear at every level. But the more time you spend thinking about watts and ohms the harder it gets to find them. |
I appreciate you guys helping out. This stuff is mind numbing if you’re not into it. My primary system is an older one that was given to me. It was researched to the nth degree by the original owner. The point being that I’ve never had to do this sort of legwork and to be honest it isn’t one of the things about being an audiophile that appeals to me. But, this person passed away and left me the speakers that I’m researching now. They are Aerial Acoustics 6Ts. Specs are below. These will be part of my secondary system which will get used much less than my primary. It is not in a room that is ideal for listening so ultimate SQ is not the goal here and my budget is limited....you might even say stretched to no more than $2000. I’ve got several threads going about this and I’m no closer to narrowing my search. Professional reviews can be all over the place and other Audiogon members can have completely different experiences than pro reviewers. One person says product 'A' is awesome and someone else says its horrible. As mentioned, the stats don’t always tell you what you need. And it almost seems like the speakers were designed to require high dollar components. Here are the specs: Frequency Response 35 Hz to 25 kHz ±2 dB, -6 dB at 30 Hz Sensitivity 90 dB for 2.83 volts at 1 meter on axis Impedance 4 ohms, 3 ohms minimum, low reactance Power Requirements 25 watts minimum, >50 recommended |
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@n80 Here's the deal: With most speakers its expected that the amp will 'voltage drive' the speakers (note that I said 'most'- not all speakers behave this way!). Now if an amplifier 'voltage drives' the speakers, IOW is a 'voltage source', the power it makes into 4 ohms will be double that of 8 ohms, with a marketing exception: it may not do that at full power. So if you are driving the amp alternately into 4 and 8 ohms, right up to nearly its rated power the 4 ohm power levels will be double that of the 8 ohm levels. But right about that point of full power this phenomena stops as the power supplies and/or output devices can't support that power doubling for that last 3dB. And that last 3dB has little to do with how the amp sounds or for that matter, how it performs on the bench. The amps you mentioned have no worries acting as a voltage source in this conversation BTW. It does suggest that a corner was cut somewhere, but in the grand scheme of things a relatively small corner, since 3dB simply isn't that audible to the human ear in terms of sound pressure! OTOH, that first watt is far more important as most of the time that will be where the amp is used most and it is entirely unaffected by this sort of thing. Now if you really want that doubling of power right up to full power into 4 ohms, be my guest but you will be spending a bit more for that last 3dB, and if you happen to own 8 ohm speakers it won't do you a bit of good. My advice is listen to the amp and see if you like it, if so take it home and see if you like it there, if so, fuggettaboudit and enjoy the music :) |
My speakers are 4 ohm speakers.What speakers do you own; brand and name of model? The most important detail in determining amount of power to drive a speaker is impedance. And the way to research a speaker is to view the impedance curve which shows how much resistance the speaker has across the frequency spectrum. Most curves can be found online. |
Where's @georgehifi when you need him? NAD and McIntosh are engineered differently, so conventional expectations do not apply. This may be a good thing or a bad thing. If well engineered a conventional Class A/B amp should double or nearly double into 4ohms. Other classes of amp bring different expectations. But it's really an extensive and complicated subject. Better to ask about specific brands/models. |
