In my situation with very efficient horns, tube power amplifiers are working well within their linear capabilities. For more demanding speaker loads - more typical ones - tubes begin to reach their linearity limits. In those situations more obvious coloration of the signal begins to take effect. At that point, subjectivity begins to assume greater importance over objective measurements.I like tubes for voltage gain. Very linear
It is. The more directivity a speaker has, the more of the imaging (or lack thereof) of the recording is getting directly to your ears. With wider dispersion speakers, the room begins to create its own 'imaging' which usually increases the apparent size of the soundstage. I generally regard this as a distortion, just as surely as any other alteration which is indiscriminately impressed on the signal is a distortion. But obviously many people like the effect and there's nothing wrong with that.My understanding is that soundstage is mainly about speaker directivity and room interactions.
A test I do to determine how much a room is influencing imaging is to play mono pink noise, but with one of the speakers out of polarity. In systems where the room is heavily influencing the imaging, this out of polarity pink noise will sound like a large amorphous blob, but very much in line with the plane of the speakers. In systems with very little contribution from the room, the pink noise will image very strongly right in front of, or at, the listener's position, and in some cases will appear to come from slightly overhead.
It can be interesting to use this technique to help determine speaker placement and
Interesting tip! Therefore, if the room has little interaction, it should sound and image similarly to the same test through headphones. I will give it a try on my three setups.A test I do to determine how much a room is influencing imaging is to play mono pink noise, but with one of the speakers out of polarity. In systems where the room is heavily influencing the imaging, this out of polarity pink noise will sound like a large amorphous blob, but very much in line with the plane of the speakers. In systems with very little contribution from the room, the pink noise will image very strongly right in front of, or at, the listener's position, and in some cases will appear to come from slightly overhead.
It can be interesting to use this technique to help determine speaker placement and toe-in.
I think the imaging of out of polarity pink noise on headphones can be sort of similar, however with very little room interaction while using speakers, it will sound almost like mono pink noise, but it will be right in front of you, or perhaps a bit overhead. It will very strongly do this if your speakers are directional enough (like full range horns), if your room boundaries are well away from the sides and rear of the speakers, and the listening position is well away from the back wall. In other words, the rule of thirds. Its almost like this technique can be used as a 'focusing aid'.Interesting tip! Therefore, if the room has little interaction, it should sound and image similarly to the same test through headphones. I will give it a try on my three setups.
Let us know how it goes. If it works well for you, perhaps this could be the topic of a new thread.Again great tip! Especially, for anyone who has not addressed the issue of room acoustics/speaker placement and their interactions. Getting this right is by far the most important thing. I have heard $2000 systems in a great room sound way better than five figure systems, in a bad room, with bad speaker placement or both.
I will let you know. I feel that my room is as good as it is currently going to get. I have some sidewall glass and a slightly longer dimension on the other side wall. I too spent many hours time aligning my driver's to my seated ear position and symmetrical placement (within 2 millimeters) and with toe-in. It makes a big difference. I agree it is almost like focusing binoculars. It's amazing how it snaps into place!Let us know how it goes. If it works well for you, perhaps this could be the topic of a new thread.
I might add that time coincidence between the speaker drivers amplifies this effect. My horns are aligned so that the drivers are physically co-incident in the vertical plane and my crossovers (active) are 4th order Linkwitz-Riley.
Shortening the speaker to listener distance is a good way to reduce room contribution too.I will let you know. I feel that my room is as good as it is currently going to get. I have some sidewall glass and a slightly longer dimension on the other side wall. I too spent many hours time aligning my driver's to my seated ear position and symmetrical placement (within 2 millimeters) and with toe-in. It makes a big difference. I agree it is almost like focusing binoculars. It's amazing how it snaps into place!
I agree Bob. Headphones are good for listening for details or when you need to not bother others but not the same. A good stereo set up has so much more life and impact.I'm not a fan of headphones for anything but casual music listening. I find that, minus the room, music loses a lot of life. Just give me some room correction is all.
Adding my 2c as well with a DR3 and an XPA-G3 amongst others, firstly I don't get how the DR would measure that bad. I tested mine when it arrived and compared it to an older Rotel class AB and they both measured at around -80 to -90db distorsion iirc with the DR amp on its lower rail voltage and I should say perfectly enjoyable in that state. Not so much on the higher rail voltages which adds distortion at higher frequencies but imho is only noticeable if you listen to music.
So all in all, if you are looking for a home theater setup the DR amps are pretty smart, most of the time the amp will stay cool on its lower rails and sound good while also being able to deliver crazy dynamics in action scenes etc. They are hard to beat in that respect and the added distorsion with the rails switching is not an issue in movies. For music you usually stay on the lower rails unless your speakers are very ineffective.
The XPA-G3 though is maybe acceptable for movies etc but not music in my setup (I am assuming they sat right at the rail switching at my typical volume level for music) so they have been repurposed as sub amps which they are really good at btw.
Right now I am testing the Hypex NC400 to understand if they can replace my DR3, I am only a few weeks in and even though they are very impressive in many ways they are not objectively overall superior in my setup so I would not swap them for the DR3 just yet.
I find the top end to sound slightly distorted with the hypex which is not the case with the DR (at lower volumes) or my old Rotel for example. It's not always a problem though but this youtube clip of birds highlights the issue in my case:@theswede I understand the passable for movies assessment. I’d think that many users are setup for double duty movies & music so are looking for an amp that can handle both well.
I’m curious what the Hypex setup is lacking in your testing. I find the form factor and the clarity at higher levels (95+ db) to be far superior to my now returned DR.