Which Lowther?
I have plans for PM6 Scott for PM4A. Scott & i can do custom designs for (some of) the others.
dave
Bumble,
We built a pair of those for PM6A in 1975. Drove them with an SQA80 (one of the worst amplifiers of all time). Built out of K3 chipboard. They sounded terrible, but played really loud. It was early in my life, i expect a lot of what we were hearing was the relevation of how bad the amp was (and how poorly built the enclosures were)
dave
We built a pair of those for PM6A in 1975. Drove them with an SQA80 (one of the worst amplifiers of all time). Built out of K3 chipboard. They sounded terrible, but played really loud. It was early in my life, i expect a lot of what we were hearing was the relevation of how bad the amp was (and how poorly built the enclosures were)
dave
You are assuming a lot of things.
The mouth are exactly as it sould be to get the right level of bass amplitude with the recommended drivers, and so are the amplitude level in the bass-midrange. It is designed as it is for a reason. To get very linear response in your room and a proper neutral sound.
They are not designed with a modeler at all. LMS is used for measuring.
I didn't like the Hedlund at all. They sounded "very lean" at best. It does give a smooth bass response, but it's soft, and so is lower midrange. It would benefit from a correction filter or DSP.
I really liked the Carfrae Little Big Horn, which had a shorter horn and filled in with a sealed box subwoofer. That had a full and lively sound. The backloaded horn shifted the crossover to the sub to an uncritical frequency, the short horn provided support to the lower midrange. And I suspect the baffle width was deliberately chosen to support lower midrange as well.
I was absolutely blown away with Lowthers in Tractrix frontloaded horns, with 15 inch woofers supporting them. The Hedlund sounded fake compared to those, the Carfrae Little Big Horns came very very close.
Lowthers peaked a bit early at the start of the internet diy and full range community. The very deliberately modelled enclosures came later. It would be good if a few cutting edge horns were made now. There are a lot of good drivers, but Lowthers have a great balance of characteristics. And that very significant history.
I really liked the Carfrae Little Big Horn, which had a shorter horn and filled in with a sealed box subwoofer. That had a full and lively sound. The backloaded horn shifted the crossover to the sub to an uncritical frequency, the short horn provided support to the lower midrange. And I suspect the baffle width was deliberately chosen to support lower midrange as well.
I was absolutely blown away with Lowthers in Tractrix frontloaded horns, with 15 inch woofers supporting them. The Hedlund sounded fake compared to those, the Carfrae Little Big Horns came very very close.
Lowthers peaked a bit early at the start of the internet diy and full range community. The very deliberately modelled enclosures came later. It would be good if a few cutting edge horns were made now. There are a lot of good drivers, but Lowthers have a great balance of characteristics. And that very significant history.
Now that everyone has decided they sound best in OB's, there probably won't be a lot of folks trying to build new horns for them.
The only thing holding me back from trying Lowthers in open baffle is the fact that you need to cross over around 200Hz. It seems like this could still cause muddling of the sound in the lower midrange, while the whole point of going with a wide band driver would be to avoid anomalies in the midrange. Seems the better option is to use them in a simple cabinet that gets to a reasonable bass frequency, say 60-100Hz, and then cross over to a sub. This is my plan, at least.
Very wrong...
Because it doesn't match your design principles doesn't make a bad design.
Listen to a pair of well tuned in Hedlund horns with the recommended driver before making statements. They can sound spectacular and very balanced.
As a basic principle you always should have heard a loudspeaker before commenting on it's sound. Don't you think that is a fundamental requirement?
Very few know what to do with a Lowther driver and they are quite hard to design with so you are probably right that there will few new horns unless Lowther design them themself.
Most of the Lowthers are not well suited for open baffle use. They is best used with a front horn or back loading horn. Some of them need both or a bit different approach like the Audiovector that sounds quite good.
If going open baffle I suggest 15 ohm PM6A with silver voicecoil. That is the easiest to work with.
Look at the measurements Lowther have presented at their website and avoid those that have a lot of dips and peaks.
PM6A 15 ohm silver is fairly straight in frequency response and a open baffle will help keep that staightness.
https://global-uploads.webflow.com/60642ec35aaa96e4388753a3/61430eb78ed96a08cf0dc8cb_PM6A.pdf
There are a few that have raising frequency response but they have a linear raising. DX2 8 ohm silver, DX3 8 ohm silver and PM2A 8 ohm silver are good examples of that, and they is best suited with back loading horns. Putting them on a open baffle will need some EQ to make the sound neutral and balanced.
Fully possible, but then you miss some of that directness a directly coupled driver gives you.
After DX3 small BR but port plugged; DX55 with dual subs; PM2A ticonal in Fidelio rear-facing horn; finally PM6A 15-ohm not-silver -- I think they are too fragile for OB and need a full load of air to push against. The 6A's ear-bleeding HF took a double notch filter to tame. Most sub/woofers reaching that high will probably sound awfully fat/muddy crossover-ed into the Lowther. I did find a resin-coated CF cone that blended well, but still a dry sound. Eventually I just mounted them in my general purpose 17L 1.5m highly-tapered TLonken.
Fully understand that you needed a notch filter to tame the HF peak in PM6A 15 ohm aluminium coil since it's very prominent.
Not so with the silver version...
Bass driver transient speed and distortion is a hard nut to crack when combining with a Lowther driver.
It can be done, but not with bass drivers suitable for open baffle. They simply have too weak magnet power.
Not so with the silver version...
Bass driver transient speed and distortion is a hard nut to crack when combining with a Lowther driver.
It can be done, but not with bass drivers suitable for open baffle. They simply have too weak magnet power.
Hi I had Lowthers for many years (10years+). Dx2s in Mau IV horns. Now with the new premium range, Im interested again. I remember what they did well and have largely forgotten their quirks 😉
I was looking at the Corner Acousta. Are the Corner Acousta cabinets the same or similar to what used to be called Delpic 500 cabinets and/or are there DIY diagrams of the Cornes Acourstas awailable?
I was looking at the Corner Acousta. Are the Corner Acousta cabinets the same or similar to what used to be called Delpic 500 cabinets and/or are there DIY diagrams of the Cornes Acourstas awailable?
Yes, the new premium series is interesting, hope to audition them one day.
The Corner Acousta cabinet plans will not be made public if I remember well. Now if you have 2 available corners, and don't mind the rather big size, the Big Fun horn is an interesting design to try, worth googling.
The Corner Acousta cabinet plans will not be made public if I remember well. Now if you have 2 available corners, and don't mind the rather big size, the Big Fun horn is an interesting design to try, worth googling.
I built corner Acousta in the 80s. That was ordinary Accousta that I added the two 45 degrees in the back but with the same crosssection as the original. I also filled the empty spaces with sand.
It sounded horrible but that was due to the Philips 9710 that is not meant to be listened to on axis.
It sounded horrible but that was due to the Philips 9710 that is not meant to be listened to on axis.
I was interested in the small size acoustas and the indirect sound (using the corner), would use them with subwoofers. I remember the Big Fun horns, had large Mau IV several years ago. Not looking for large have Altec A5s with 1505 multicells and recently sold Altec 604 in 620 cabs.
I baby-sat a pair of dual-position Acoustas once for a friend when he was moving and needed to store them. They were fitted with DX3's IIRC. I quite liked the sound, especially given their small size. I wish it was possible to find plans to build them, but they seem nowhere to be found.
http://www.lowthervoigtmuseum.org.uk/lowtherDualPositionAcousta.html
http://www.lowthervoigtmuseum.org.uk/lowtherDualPositionAcousta.html
Corner Accousta has the driver facing back into the corner angled upwards and the bass from Voigtpipes.
The Decca corner horn has the very same features, and it sound really nice. I built it and tried several drivers and was surpriced by how good the sound was!
https://www.itishifi.com/archives//2013/07/decca-voigt-corner-horn-1950s.html
The Decca corner horn has the very same features, and it sound really nice. I built it and tried several drivers and was surpriced by how good the sound was!
https://www.itishifi.com/archives//2013/07/decca-voigt-corner-horn-1950s.html