Please keep us informed.
Please keep us informed.
Here are a couple of chat rooms which may be of help:
http://members.aol.com/cycarpio/home.htm (BBS portion)
The second site is mainly in Japanese, but I had no problem asking and receiving info in English (Zuki and a friend supplied the cabinet plans for a vintage pair of Stephens 8" drivers), these guys/gals are great. There is another site in Italy, but I have lost its address (perhaps you can locate it)?
Sorry no cabinet design tips from me (as you know I am new to this), but looking forward to your take on the "new" Lowther's.
Twl, I'd be very interested to hear about your experiences with these Voight pipes, since this is a project I'm also considering in the long run (being very satisfied with my current system, I want to keep myself busy with building a SET amp and if that turns out ok, I'd like to have some high efficiency speakers to go with it). However, I read a few contradictory things about that particular pipe design, most people claiming they're fantastic but I also recall a posting somewhere stating they are mid-fi at best. So it'would really help getting an evaluation from a seasoned audiophile.
Pipetman, I'd be glad to keep you updated on the project. I generally run a thread on my results. Regarding the Voigt Pipes performance, they do have issues with some "comb filtering" in the bass and midbass due to wave additions and cancellations from the port/direct radiator interface. This can be dealt with to some degree with appropriate tuning. Regarding the "mid-fi" comments, I can only laugh. Even the earlier Lowthers were considered to be world-class drivers by nearly everyone. Not everyone wanted single-driver systems, but there was little that could do more or better than a Lowther driver. The Voigt Pipe may not be the ultimate cabinet, but it is a good one. There is not a speaker system made that does not have "issues" of one sort or another. This is my way in to the High-End single driver arena. While I am breaking the drivers in, I can evaluate the Voigt Pipes. If I am satisfied, I can stay with them. If I feel the need to move up to some more exotic back-horn, I can then build a pair of them. The Lowthers need alot of break-in time, so it is imperative to get them going in some cabinet right away.
There is another cabinet that looks to have a lot of potential and is a variation of the Voigt Pipe. I saw it on the Single Drive website under the DIY menu, titled: Bigger is Better. Basically, it looks like the Voigt Pipe but has the "other half" of the Pipe attached, and the port/mouth opens up toward the ceiling. The fellow that built these speakers has some tips in building them that may be useful to you when you build your Voigts.
Please keep us udated on your Lowther DX-3 Voigt speakers.
Yes, I've seen that one and it does look interesting. I am trying the regular Voigt Pipes first, because my ceiling is vaulted, and the Terry Cain upfiring pipes may not get much bass boundary reinforcement from my ceiling. The Cain pipes would gave to give at least 3db more bass in order to compensate for the loss of boundary reinforcement. Also, when I experimented with transmission line lengths in my last set of single driver speakers, I found that at some point, longer line and lower tuning can result in loss of output level. Since the Voigt pipes act as a T-Line and a kind of horn, this may be mitigated somewhat, but the mouth size is way to small for a real horn and would reflect alot back up the throat if pressed into being a real horn, drastically raising the cutoff frequency. Also, they act as a bass-reflex somewhat, and the box volume would be doubled, requiring much tuning of the port mouth. Cain designed his pipes for a smaller Fostex driver that has a significantly higher resonant frequency, and likely lacks the bass output of the Lowther. The Lowther, having a resonant frequency of 36Hz should be good down to 40Hz-50Hz in the traditional Voigt pipe cabinet. This is fine with me. I'd like to go lower, but I can live with 40Hz. If I decide I really need the extra bass, I will build the "Big Fun" horn with a cutoff of 32Hz on the low end. Efficiency of the DX3 in all these back horn cabinets is about 100db with 1 watt input. The only way to go higher is to go with a front horn, which I don't like to do because of colorations imparted to the mids.
"I can live with 40Hz"
I agree Twl. If the speaker handles 40Hz really well it's much betteer than having something that stumbles over something lower. I've been building two ways for a couple years that max out at 39Hz, but handle that well, and for lots of music I never miss a thing.
I am moving in your (FR) direction though.
Continue to let us know what your doing and how it's going.
This again brings us to the perennial question of whether we are listening to the sound or to the music. It is pretty clear when twl makes statements like "I can live with 40Hz" that he is opting for listening to the sound.
THERE IS NOTHING WRONG WITH MAKING THIS CHOICE. Please...hear that.
In my judgment (not revealed truth, just my judgment) this is why people choose tubes over SS and vinyl over digital: They want to listen to the sound.
That's a good choice...a legitimate choice...in every way a valid choice.
But that is not the same as listening to the music.
Off to NYC for a week of concerts and shows. Y'all have fun! Great 4th of July to all!
Here's another variation of the Voigt Pipe that you may be interested in: http://indigo.ie/~walton/voigt.html Also, there is a construction tip on the Pipes at that site.
The "Pipe" is a bit larger than the original and has a modification at the bottom of the cabinet, which according to the builder, helps smooth out the bass response.
Bishopwill, if the "sound" never reaches my ears, I cannot hear the music. Music is a sonic phenomenon, in presentation, at least. I am not going to take your bait for the analog/tubes vs digital/SS debate. I have stated my points on those issues on other threads. If my speaker design choices, source component choices, and amplifier design choices are not your "cup of tea", then by all means, make your own selections. I use over 30 years of listening,studying, designing, building, buying, and employment in high-end audio shops, as well as being a musician, concert goer, music and record collector and enthusiast, as my basis for my choices. I have listened to virtually every type of music and every type of equipment made for its reproduction. I have a strong background in music, its theory, practice, and performance, and a strong technical background as well. I feel well equipped to make good decisions for my listening needs. I fail to understand why you, and a few others, need to follow my posts around the forum, making sugar-coated insinuations about your perceived lack of ability on my part to understand music, its reproduction, and technical merits of various designs.If you have additional problems with me, please take it off the forum and email me personally.
TWL: Had I suspected this of you earlier on last week, I would have picked up and shipped, gratis, a few dozen sound effects LP's that I stumbled across @ a local thrift (many still sealed), just to get on your good side (may need some help/ good advise on my single driver project down the line:-), though sub 40 Hz is really required to properly hear all of the "kids in the pool" on the "toilet flushing" track. LOL. You still here Kelly, (how's that for a run-on sentence)?
Any of you guys old enough to remember the magic of those old German tube radio's? I realize Twl is talking about WAY better fidelity, but still............there was a simple unfettered magic in the sound.
Makes me wonder, anything wrong with wanting to have fun with this as well as listen. I wouldn't mind a smile on my face as I spun my favorite LP.
Albert: I had the pleasure of attending a local "single driver" get together a few weeks back (hosted by Thor over @ the single driver website). I arrived rather late and did not get to listen to everything, but the overall coherency of sound of the designs that I did audition was quite amazing, as was the separation of voices and instruments.
Yes, @ 47 years old I remember the sound of many radios and stereo consoles that used single drivers or coaxial/triaxial speakers with a single point source. My father had a pair of Stephens Trusonic coaxial speakers (big ones) mounted in the ceiling of our basement rumpus/game room. Oddly enough my first single driver project may be based on a smaller version (8") of the Trusonic's.
Bruce Edgar was @ the event, which also got me thinking of some of his smaller horn designs (don't think that our room is big enough though).
No, no, NO, twl! You've missed my point completely. And you've gotten defensive, which was NOT what I wanted.
You and I have been through this before. If the composer didn't want you to hear pitches below 40Hz then s/he would not have written them. So by definition, dear friend, when you truncate the audio spectrum you are choosing to listen to something other than what the composer intended you to hear.
This has nothing to do with how technically or musically literate you may be, as I think you very well know.
It is borne in upon me yet again that nearly any sort of attempt at this kind of discussion will be overwhelmed by ideological pronouncements cast set forth in the language of martyrdom or righteous wrath. Very wearying.
You wrote: "This again brings us to the perennial question of whether we are listening to the sound or to the music. It is pretty clear when twl makes statements like "I can live with 40Hz" that he is opting for listening to the sound."
Not only is it NOT "pretty clear" but I think you introduce a complete, and quite unkind, non sequitur. If one looks at any materials on designing or building audio equipment the discussions are all the same. They do not, for the most part, or at least at the beginning of the design stage, stay in the language of music, but rather in the language of electronics and acoustics. It can't be helped. Don't blame Twl for it.
You will not get to first base without asking the simple question: what do I want the equipment to do? A most basic aspect of this process is determining frequency response for the piece you are building (amp, speaker, whatever). The folks who developed your lovely Utopia's undoubtedly talked in this manner. Does it mean that they have choosen not to listen to music and are only interested in sound? That is ludicrous. It simply means that they have turned off the record player for a while and stopped listening to music in order to work on audio equipment. It's not that they have choosen not to ever listen to music. It's just at the moment they are doing a different thing...designing audio equipment. It is somewhat akin to saying someone who practices scales is interested only in technique and tone and not music when, in fact, one follows directly from the other.
Take another example. Some time ago you were involved in helping a friend build a listening room. This entails looking at and talking about rooms in terms of sound and acoustics. In describing the first steps in this direction one might say something like this: Well I established the basic axial resonant frequencies of the room by dividing the speed of sound by the 2xlength of the room. (1130/2L). Finding the basic resonant frequency to be 44Hz, I put on a frequency disk on the stereo and fired her up at 44Hz and walked around the room trying to identify high pressure points in the room. I then built a few bass traps tuned to that frequency and started experimenting with placement of them based on the SPL measurements. (Your first steps in tuning a room may differ and be much better(not the point.)) The point is that tuning the room inevitably requires an approach, and discussion, along these lines and it resembles Twl's talk about speakers. It can't be avoided! It would be pure folly for someone to say "See, the Bishop is only concerned about sound and the frequency response of his room and has choosen not to listen to music."
Of course, when such measurements and things are done you will sit back, turn on the music, and your ears will be the ultimate judge. But your ears alone will never tell you HOW to build a good sounding circuit or what to do in order to make your listening room sound musical. They will tell you when and if you do it. But never HOW to do it.
I've read some of your posts and you are not stupid. The point above is so obvious, that I find it hard to believe you do not see it. It almost makes me agree with Twl that you are setting out to insult him (as sugar coated as the insults are).
In any event, I'd like to see Twl keep posting so I can learn from his Lowther project and would appreciate it if you would respect his request. He might otherwise stop posting or something and I'll lose some valuable insight into FR drivers.
Dekay, it's good to hear that you and others are considering the benefits of single driver systems. I'm sure you know that you needn't "get on my good side" :-) in order for me to try to give you any assistance I can. My main reason for doing this type of post is to help others see that there are some different ways of doing things in audio than the usual run-of-the-mill. And to help them benefit from my experiences, good or bad. Apparently, there are some who would ridicule me for my views. But, they are far in the minority and I prefer to concentrate on my projects and helping any members that may be interested. If I can be of any help to any of you, please email me, and I will give close attention to your needs, and give whatever help I can. I do not claim to be the ultimate authority on these subjects, but I am working with these concepts and products, so I do have some good working knowledge of them. As for the 40Hz cutoff for the Voigt Pipes, I may not even quite get down to 40Hz, but I will try to get what I can without sacrificing any midrange quality. I would love to get to 20Hz, but it's not possible with this design. My efforts are to get the most from the least and typically that will entail some trade-offs, in this case, the deepest bass is REDUCED but not eliminated. While some may consider this "sacrilege", I feel that all designs are limited and one has to pick their weak points as in all engineering and design work. My preference is to accept lower output in the 20Hz-40Hz region, in order to get the advantages offerred in the rest of the spectrum by single driver designs. There are more exotic cabinets available that will give 32Hz cutoff for the same drivers. Maybe, down the road, I will build them. I feel honored that Albert, in particular, is interested in my efforts in this area, because of my great respect for his knowledge, experience, and integrity. At the end of this road, we will know more than when we started, and that, in itself, is worthy of the effort.
Bishopwil, I remember our previous discussions, and I am not in conflict with your statements regarding the proper reproduction of very low bass frequencies and their effects on the composer's intended sound. As I posted above, I am simply making a conscious decision to accept this weakness in order to get benefits in other areas. We may not agree on the "sacrifice" of flat response in this octave of the spectrum, but I think we will agree that no product is perfect, and we all "sacrifice" something with every audio product we buy, so we can get the things that we do want out of them. Upon looking back to my statements on other threads, this may apply to the other diagreements we may have had on the other topics. Perhaps I should have been less forceful with my statements. While I may have been rather "absolutist" on the vinyl topic, I am not nearly as "absolutist" on this topic. However, I have selected a path, and I am traveling it. Things will be learned on the way. Others may benefit from my experience. Ultimately, my conclusion may, or may not, support my premise. We shall see. If I misinterpreted your intentions in your post, I am truly sorry, and have no desire for conflict. I do have certain sensitivities, as does anyone, and can react defensively.