New Lowther Drivers.

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.

Sounds like a great project. Please do keep us informed.

will

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.