I know everyone hates this kind of response, but, it depends on the speaker. Most would say that electrostatics and some other planar and ribbon speakers have excellent transient response, but they generally have pretty low sensitivity in the mid to low 80db area. There are also some subwoofers that have efficiency of over 93db that are slow as molasses. Regardless of efficiency levels, the transient response game is usually won by lightweight radiation surfaces with short movement, and high power magnetic driving mechanisms. Sometimes this relates to high sensitivity speakers, but not always. |
Again, we arrive at the inevitable conclusion, every design has its flaws.
For Mwilson, I have been using Lowther fullrange drivers recently and they have 98db/1watt efficiency unloaded, 100db/1watt in a cabinet. In my cabinet, they are good down to the low 40's, and they have a resonant freq of 36, so I am not "on the spike", but rather rolling off a few db above it. This leads to a rather steep low cutoff which you can either live with, or integrate a very good sub. Right now I am living with the 40Hz bottom end, and it is quite enjoyable, although there are some records that display the flaw. But, the natural tonal quality, and speed, detail and phase coherence makes up for the 1 bottom octave of missing bass response. I know some disagree with this thinking, but few audiophile speakers actually produce much below 40Hz without some rolloff. So the sound is not really lacking much compared to most others. I have toyed with the idea of integrating a pair of TL subs of my own design, but haven't done it yet. If you have not listened to some Lowther systems, then you should really try to find some to audition. A quite remarkable full range driver. |
Marakanetz, I do indeed enjoy your posts and feel you are a very informed and perceptive individual. On the high-efficiency speaker with SET comment you made, though, I believe you are in error. If you sat down in front of my system which consists of a 1 watt triode OTL, and a pair of Lowther 100db/1 watt fullrange, you would wonder how anyone could say that "voice is the only thing you can listen to". Granted, the bass is somewhat limited to around 40 cycles and there is some "vented" sound to the lowest bass. But,it is very, very good from there on up to 22kHz. As I said in my last post, many other high-end speakers also roll off around 40, and have vented bass, so this is not unusual. Many extreme audiophiles consider this type of system to be the most musical and natural of all systems. They are not idiots. There is definitely something to be said for this type of system. I am hoping that you were exaggerating your point somewhat, because wide-frequency extension is not limited with these systems with the exception of the lowest octave. Some lesser-quality transformer-based SET's may roll off the highs due to transformer induced problems, but not on my system. In any case, the addition of a sub would cover all freq's well, and this is quite common with many types of other high-end systems as is well-evidenced by the plethora of subwoofer threads on this forum. I felt the need to take issue with that statement, because I thought that it was too stereotypical, and an overstatement. Our members who do not know about SET/high-efficiency systems deserve a fair assessment for their knowledge base. I take no personal issue with you, but only wish to set the record straight. |
Marakanetz, perhaps you just prefer the sound of push-pull amps better than SET's. There is nothing inherently wrong with push-pull amps, and they have more power to kick the bass a little harder. My little Berning amp is actually a push-pull, using 6SN7 preamp tubes for outputs, and maybe that is why I don't feel that the bass is lacking like you say the single-endeds are. Whatever the reason, this little MicroZOTL kicks some booty on the bottom end. Really tight too. |
I just checked out the Brentworth line on the web, and it seems interesting. Their specs on the top line model show a response of 15Hz-20kHZ within 3db. I find this a little hard to swallow, but they claim it. Seems they have a proprietary loading technique that supposedly allows this to happen. I've never heard them. If they sounded weak in the bass, that would be understandable, as I strongly suspect their figures. However, their idea could be a jumping off point for others to work with, and produce lower bass out of a single way system. The main question is: how do they sound in the rest of the spectrum? If they are no good there, then the bass is of little use. If they are great, then maybe I need to consider them for my system. About the comparison with the B&W's, the B&W's are a well made speaker that conservatively rates their systems, and may actually produce lower bass than their rating, in your room. In any rate, they are a good speaker, and I don't know if the Brentworths are good or not. It is notable that some single driver speaker mfr. is claiming to be able to get that kind of bass response, though. If you can tell us a little more about your impressions of the Brentworths, that would be very helpful. |
Well,CDC, it sounds to me like a classic case of a particular design doing some things very well, and some things not so well. Many of the things you didn't like about the Brentworths are not weaknesses in the other brands of single-driver systems. For example, punchy dyanamics and excellent high-end extension are strong suits of the Lowther single-drivers. They are usually somewhat bass-limited by the back-horn designs, but will generally do about 40Hz. As low-excursion 8" drivers, they are never going to "rock your world" in the bottom end category. But, it is there, and solid, and accurate. Fostex will roll off a little early in the high-end, and so will Diatone.
One of the things that concerns me about their claims of 20Hz bottom end, is that your listening experience does not seem to bear out their claims. So, at best, in my book, these claims are doubly questionable now.
About the proper soundstaging you heard, that is a characteristic of good single-driver systems. The point-source and phase coherence really enhances imaging and soundstaging.
I'm not really sure what you mean by "distorted immediacy" and "pleasant distorted" sound about SET's. I don't seem to get that impression at all. I understand they have some issues at some frequencies, but I can hardly believe that the high end Wyetechs were having transformer-related problems. Perhaps it was the speaker's shortcomings you were hearing. Also, I find the taste for bass "punch" is highly variable, with no 2 people really agreeing with how much there should be, for enjoyable listening.
I'm glad you were able to inform me about your listening experience with the Brentworths, since I had no contact with them, and have benfitted from yours. Thanks. |
CDC, the new Lowthers do not have the midrange peak anymore. They have been updated and the mids are now smooth. If you heard noise like a "fan blade" out of a SET amp, there was definitely something wrong with it. They do not normally have anything like that in their sound. Perhaps it was going unstable and oscillating for some reason, but believe me, wierd sounds are not normal for SET's. As far as distortion numbers go, they do not relate to the sound of an amp, as the measurements are not taken with music input, only steady-state tones which cannot reflect the amp's behaviour in real world conditions. This is why cheap recievers often have better "specs" than $30k amps. Whoever told you about the "high amounts of distortion in SET amps" has quite a bit to learn about audio. Those types of remarks are the sign of a rank amateur who has not yet learned much about any kind of audio designs. Avoid any more of his counsel, as he obviously is in no position to counsel anyone, since he is in dire need of counsel himself. I advise you to continue listening to various kinds of gear, as you have been doing, since it seems you have a good ear. You will be better served this way, instead of being influenced by prejudicial comments of unknowledgeable individuals. Don't worry about finding fault with everything, because everything has its faults. No design is perfect. If you know the faults, it can help you to decide which type of gear you will prefer. But use your own ears to hear the faults, and don't rely on others opinions. |
CDC, according to the Brentworth website, their models use a 6.5" cone single-driver and a combination of aperiodic and transmission-line loading, called BSL. They are not planar types. |
Sean, they don't give the details on the website, other than it is a line with "valves" to control air flow. That sounds like what you are talking about with the stuffing. I've never experimented with something like that before. It seems like an interesting concept, but I don't know how well it would work. |
I am assuming that was Sam Tellig that you quoted. First, he is making a totally "out-of-hand" statement, based on the measurements of a single ended tube amp design. This is obvious, as he refers to "adding negative feedback" as some kind of fix for distortion. It was known more than 25 years ago that negative feedback is NOT a fix for distortion in a real world environment, but only on the steady-tone measurement bench. No really good single ended tube designs that I am aware of, use any negative feedback in the circuit. Their "measured" distortion shows up as higher than SS on the bench, but not in the listening room. It is really sad that a person that writes for an audiophile publication is so ignorant and misinformed. Perhaps now you see why some of us have such little respect for the reviewers in the audio rags. Not all single ended tube designs are great, or even good. But the good ones are capable of doing the job as well or better than any amp out there. No audiophile in his right mind would spend $10k on a single ended tube amp that had so much distortion, that he couldn't listen to it, and no company would expect to sell such an amp. In fact, there are a good number of "hardcore" audiophiles that wouldn't use anything but a single ended tube amp, because they feel that only SET is capable of meeting their stringent sonic requirements. To sum up, a SET does not have higher "real world" distortion, and may actually have less than other amps, measurements notwithstanding. |
Well, I can agree with the last statement to some degree with some amps, but the earlier statements about the unlistenable distortion is just plain wrong. My statements that were inaccurately aimed at Sam Tellig can now be applied to Mike. Apologies to Sam. And just for the record, I do not have a SET amp. I have a push-pull triode OTL. So I am not on some kind of personal SET crusade or anything. But I have heard some SET amps that are fantastic and could never be characterized as "unlistenable" for anyone. |
I'll try to remember that next time I cue-up a specifications sheet on my turntable. :^) |
