@profiguy
I have some evidence that supports this theory. It's in my small directivity study that includes Volt VM752
I have some evidence that supports this theory. It's in my small directivity study that includes Volt VM752
I am not aware that anyone was engaged in such. As far as I am aware, we all share the same goal and discussion is always directed at achieving that goal. All useful practical information is backed by some degree of technical explanation, and as discussion moves towards resolving ever-decreasing performance advantages, then exploring new information is inevitable. This is definitely not a forum for "cloth ears".
Stereo recording contains no vertical information. Any such effects you describe are likely due largely to peculiarities of your loudspeakers. It is not clear if you wish to avoid these distortions or amplify them? My posts refer only to the former aspiration. (It is also of note that my comments will also apply even if you are referring to bi/transaural-type recordings or material processed to emulate such techniques. The added artifacts will still be additional to the intended reproduction).
This is good advice, but in the horizontal plane phase errors can be avoided completely by implementing crossovers that compensate for the acoustic components due to the drivers - and also by providing for time alignment of the main radiating lobes at the nominal listening position. These will likely need to be provided by separate crossover elements in an analogue crossover.
In the horizontal plane, this is false if the crossovers are implemented to be acoustically complementary. The effects you described are caused either by not accounting for the acoustic elements due to the drivers, or by artifacts in the vertical plane due to the multiple driver interactions. Compensating for the latter can only make the former worse. (That is sound theory btw, not mere conjecture).
This is true, but for much the the reason cited above, it is always better to fix matters at source. And if widely spaced drivers and high crossovers are unavoidable, then as I remarked previously, notched crossovers are worth considering.
This is also true, especially where acoustically soft diaphrams produce smooth HF roll-offs. Achieving such with 75mm domes is nevertheless a hard task if you choose to adopt an HF crossover in excess of 3.5kHz, or much less with a lower than fourth order crossover. This thread already contains lots of discussion re this particular compromise.
I always maintain a purely analogue pathway too, but that does not exclude analogue active crossovers, which, when implemented well and used with well-behaved drivers, will yield most of the advantages offered by DSP. Just as reflected previously in my response here, the use of DSP to "fix in the mix" is not without problems.
DSP is never wisely described as a "cure for all ills" where loudspeakers are concerned, and my comments were never meant to imply such. I would even go as far to say that if a loudspeaker does not perform naturally and transparently in an analogue implementation, then it will not be a top-flight loudspeaker with DSP added either.
@tktran303 I would agree with that link. I know many people say the Volt has issues around 2.4k, but in reality its diffraction related and fixable, since it disappears off axis. The main problem with it is the 4.5k sharp wiggle. Thats a cancelation issue and needs to be notched out with the other driver's response reacting to it with similar phase (hard to do without DSP), then filtered. I dont mind the Volt752, but I believe the M74A is a better driver and a little less expensive.
The M74 drivers are not on Bliesma website; distributor Soundimports indicate M74 drivers being NDA - "end of life"; most vendors have no stock.
Unclear what this has to do with beryllium shortage.
German AOS had some M74T prototypes (textrene domes....).
Does it make sense to discuss Bliesma drivers as long as availability is so uncertain?
@soundbloke I won't argue with you on most of those points. Obviously you're not new to this whole speaker thing. In the past with other threads I've started, there's always that one guy who wants the last word. I dont mind others coming in and setting things straight if they have good intentions. Its when things turn into a pi$$ing match, that's when it goes south fast. I dont mind disagreeing with anyone, as long as the other person can do the same and leave it at that. I agree, it should be common goal oriented and resolving, but with respect and courtesy to others.
No, in theory the vertical plane isn't accounted for in a stereo recording. However, the brain will piece together its own picture and if the drivers aren't located reasonably close, integrating in relative phase, they become acoustically "visible" and ruin the believability of the stereo image. The drivers of a well designed speaker system should always disappear and not be easily located. The one thing that will always mess that up is when the phase tracking isn't correct.
Just because FR is linear doesn't guarantee smooth phase tracking. The main reason I don't like to fix things with DSP (other than not maintaining a fully analog signal path) is that it adds its own set of audible artifacts ie. pre-ringing. Active and passive analog filters dont do that, but have their own set of issues, especially when trying to achieve theoretically perfect response with steep slopes.
LR24 can work well if its necessary, but I don't like the multiple phase flips you can get when employing many steep cutoff slopes in a 3 way or larger system. Yes, it may track correctly in relative phase, but it makes transient rich material fall apart and become muddled.
The big test for any decent speaker is acoustic piano. If it can't reproduce that correctly timing and FR wise, it's not an accurate speaker. Vocals are another area of importance, but that mainly requires a solidly, well dampened enclosure and breakup free, linear drivers.
The big advantage mid domes have over cone mids is the lower Mms. As I mentioned above in my last post, some drivers have FR discrepancies which aren't always due to breakup resonances, but often diffraction artifacts. These can be easily removed with proper baffle construction and driver mounting schemes. The big Volt dome has that 2.4k issue cause by the sharp WG transition to the baffle opening edge. Using a 1/2" roundover at that junction almost fully corrects the issue. Thats why I like the small round over the D7608 has, which also makes the driver less sensitive to cabinet edge diffraction.
Its difficult to fully avoid cabinet edge diffraction, but you can avoid the resulting majority of issues through smart choices in baffle layout ie. not having port openings close to HF drivers and chosing drivers with smaller lipped surrounds. Small problems can add up to bigger ones very quickly, so attention to detail is critical with baffle layout and proper countersinking of driver baskets.
There are unfortunately some people who believe you can take cheap components (like Bose) and pound them into shape via DSP. You know that never works out in the end, even when the drivers operate in their most linear area dynamically and phase wise.
Off axis power response is important to a point, but you can't just focus on it, neglecting to address other equally critical things.
Many times I see designs with excessively low crossover points used on small diaphragm drivers. This may fix power response, but it creates an even bigger issue by operating the driver in its fundamental resonance range, especially when pushing the driver past xmax thanks to the low xover. Very few HF drivers can cope with low xovers and it depends on a few design factors. Most of them will start making noises of their own, which can't be fixed.
These other issues I mentioned are usually more detrimental than dealing with minor compromises in power response. In a commercial application, even coverage is a little more of a priority, but in domestic hifi settings its significantly more important to avoid irreversible coloration in the super critical midrange. You can always use a little EQ to obtain better average power response off axis, but you can't fix the nasal, honking resonant noises created by excessively low xover points. This problem gets exponentially worse on CD/WG equipped speakers, but thats a whole different topic altogether.
No, in theory the vertical plane isn't accounted for in a stereo recording. However, the brain will piece together its own picture and if the drivers aren't located reasonably close, integrating in relative phase, they become acoustically "visible" and ruin the believability of the stereo image. The drivers of a well designed speaker system should always disappear and not be easily located. The one thing that will always mess that up is when the phase tracking isn't correct.
Just because FR is linear doesn't guarantee smooth phase tracking. The main reason I don't like to fix things with DSP (other than not maintaining a fully analog signal path) is that it adds its own set of audible artifacts ie. pre-ringing. Active and passive analog filters dont do that, but have their own set of issues, especially when trying to achieve theoretically perfect response with steep slopes.
LR24 can work well if its necessary, but I don't like the multiple phase flips you can get when employing many steep cutoff slopes in a 3 way or larger system. Yes, it may track correctly in relative phase, but it makes transient rich material fall apart and become muddled.
The big test for any decent speaker is acoustic piano. If it can't reproduce that correctly timing and FR wise, it's not an accurate speaker. Vocals are another area of importance, but that mainly requires a solidly, well dampened enclosure and breakup free, linear drivers.
The big advantage mid domes have over cone mids is the lower Mms. As I mentioned above in my last post, some drivers have FR discrepancies which aren't always due to breakup resonances, but often diffraction artifacts. These can be easily removed with proper baffle construction and driver mounting schemes. The big Volt dome has that 2.4k issue cause by the sharp WG transition to the baffle opening edge. Using a 1/2" roundover at that junction almost fully corrects the issue. Thats why I like the small round over the D7608 has, which also makes the driver less sensitive to cabinet edge diffraction.
Its difficult to fully avoid cabinet edge diffraction, but you can avoid the resulting majority of issues through smart choices in baffle layout ie. not having port openings close to HF drivers and chosing drivers with smaller lipped surrounds. Small problems can add up to bigger ones very quickly, so attention to detail is critical with baffle layout and proper countersinking of driver baskets.
There are unfortunately some people who believe you can take cheap components (like Bose) and pound them into shape via DSP. You know that never works out in the end, even when the drivers operate in their most linear area dynamically and phase wise.
Off axis power response is important to a point, but you can't just focus on it, neglecting to address other equally critical things.
Many times I see designs with excessively low crossover points used on small diaphragm drivers. This may fix power response, but it creates an even bigger issue by operating the driver in its fundamental resonance range, especially when pushing the driver past xmax thanks to the low xover. Very few HF drivers can cope with low xovers and it depends on a few design factors. Most of them will start making noises of their own, which can't be fixed.
These other issues I mentioned are usually more detrimental than dealing with minor compromises in power response. In a commercial application, even coverage is a little more of a priority, but in domestic hifi settings its significantly more important to avoid irreversible coloration in the super critical midrange. You can always use a little EQ to obtain better average power response off axis, but you can't fix the nasal, honking resonant noises created by excessively low xover points. This problem gets exponentially worse on CD/WG equipped speakers, but thats a whole different topic altogether.
@daanve I wasn't aware of this. I wonder why they would decide this? Maybe due to lack of sales? The Be version is just so expensive and IMO doesn't perform as well in some ways. The cost of it puts it out of reach of most diy people. Thats another reason why I prefer more reasonably priced drivers which are more accessible. Even the Volt would be a better choice as a soft dome, but its problem is the massive motor.
does anybody have any good projects to point to using the cheaper morel dome ? I wondered if there's any way to integrate a shallow waveguide just to make it look better than that square frame
This is a public forum, and I am certainly not here because I want to have the last word. But I will correct any errors or the misquoting of my contributions. Other than that, I am leaving 'your thread' for good as it is clearly not here simply to support learning via the sharing of information.
Phase tracking has nothing to do with whether a crossover is linear phase or not (or linear magnitude if that is what you meant?). Nothing I wrote implied linear phase.
DSP can implement any filter response ranging from minimum phase through linear phase to maximum phase. Pre-ringing is therefore not inevitable when using DSP.
Yes they do! At least, all useful crossover filters ring to some extent. The advantage of complementary phase tracking filters is the cancellation of ringing (at least on the measurement axis).
Only where crossovers are not correctly aligned or where vertical layout imposes an additional problem.
This is far too simple a statement. For an example, having no cone edge is another advantage, all else being equal.
Practically impossible in fact unless employing some form of cancellation. But wide baffles, or infinite baffles as targeted in soffit mounting, can largely ameliorate any detrimental diffraction effects. Being constrained by a dome's higher LF crossover than might be enabled by a larger dome actually helps here if a sensibly sized "wide baffle" is wanted.
Have my previous posts re the inherent comprises evident using 3" domes not made this clear? I have neglected nothing of which I am aware, but I am happy if you wish to correct me.
I agree, but that was the point I tried to make when I wrote previously of the history of the 3" dome development - the lack of horn loading was intended to be its big advantage.
don't go 🙁 I for one was really interesting hearing the history of how the atc middome came to own the studio market this was before my time so nice to hear about this sort of thing . do you consider the more modern horns have mostly solved all these problems or not ?
I would be EXCEEDINGLY interested in a textreme domed M74. Who is German AOS? Any other information you can share?
This would be off topic, except you brought it up and it's your thread. I've really wanted to add some piano tracks to my test-track-list. Could you provide a few recommendations?
Firstly, thank you for your thank you. My personal opinion is that well-designed horns can help with maintaining directivity, but their original application was for developing higher SPL's. This has advanced too, where added colourations might be considered minimal. But modern direct radiators have obviated the need for horns in most applications, and in doing so obviate any such colourations completely.
thanks so if you were building no holes barred best you could build what would you use today for midrange and all the drivers please . I've got 2pairs dynaudio 24w100xl and a pair d76 and two different dynaudio tweeters . just struggling to find the time to finish the baffles . would you use something different for the midrange if you were me ? I'm trying to build the best I can
@jcccart: The magic is in the x/o, properly integrating your drivers, which by themselves are fine. I notice there is a lot of emphasis on the characteristics of the individual drive units here -which in itself is certainly relevant- but proper x/o design i.m.o is much more important for "system" design.
As the step by step Monkey Box design description here on diya shows, measuring the crucial 200-1000Hz band is not trivial with the usual diy measurement gear, because of reflection issues. You need to put the testbox up at least 2 metres from any reflecting surface for your baseline measurements in order to obtain raw driver measurements with some accuracy in that band. Why? Because your low-mid x/o point lies right in that band.
As the step by step Monkey Box design description here on diya shows, measuring the crucial 200-1000Hz band is not trivial with the usual diy measurement gear, because of reflection issues. You need to put the testbox up at least 2 metres from any reflecting surface for your baseline measurements in order to obtain raw driver measurements with some accuracy in that band. Why? Because your low-mid x/o point lies right in that band.
OK thankyou I could make a measurement setup in the back garden . I'm assuming that includes 2 meters from the floor ? in which case I can see hoe that could get a bit more difficult but not impossible
Read all about it in the Open Source Monkey Box thread and you will know how to execute the work. The measuring and simulating fun starts at approx page 10 and then goes on some 40-50 pages. Doing it right is not trivial.
https://www.diyaudio.com/community/threads/open-source-monkey-box.327594/page-10
https://www.diyaudio.com/community/threads/open-source-monkey-box.327594/page-10
I'll gather a small list of titles for you. 99 percent of my digital source audio is on CD. SACD and DVD-A. The remaining majority is in PCM of various sample rates on HDs and removable storage. I don't listen to anything compressed unless its for a client.
I am not sure if anyone cares what I listen to, but here are a few of my favorite piano recordings for evaluating speakers. These seem to be very well recorded.
The Franz Vorraber / Franz Shubert recording has a very forward presentation, as if the listener is not in the audience, but next to the keyboard.
The Franz Vorraber / Franz Shubert recording has a very forward presentation, as if the listener is not in the audience, but next to the keyboard.