Hello,
I'd like to put my Lowther PM6Cs in the speakers boxes pictured. My first thought was to just cut a hole for the drives above the current base units and the replace the base speakers for new ones. I have previously had the Lowthers in large (home made) horn enclosures and though they lacked in the lower register. This is why I'm tending towards a separate base unit rather than trying to coax out a full frequency range from the Lowthers. I wondered if anyone out there had any ideas or suggestions? The proposed enclosures measure 40 x 25 x 84 cm and have small rectangular ports at the bottom of the back. As can be seen on one of the pics, there is a board running through the centre of the speaker - might this be some sort of transmission line set up? Any advice gratefully received.
Cheers!
I'd like to put my Lowther PM6Cs in the speakers boxes pictured. My first thought was to just cut a hole for the drives above the current base units and the replace the base speakers for new ones. I have previously had the Lowthers in large (home made) horn enclosures and though they lacked in the lower register. This is why I'm tending towards a separate base unit rather than trying to coax out a full frequency range from the Lowthers. I wondered if anyone out there had any ideas or suggestions? The proposed enclosures measure 40 x 25 x 84 cm and have small rectangular ports at the bottom of the back. As can be seen on one of the pics, there is a board running through the centre of the speaker - might this be some sort of transmission line set up? Any advice gratefully received.
Cheers!
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I'm Curious! They look like they were a pretty good set of speakers in their day But they don't sound too good now so I think they will get butchered. At the moment I'm leaning towards a Acousta type set up.
Thanks to you guys for your deep knowledge!
Thanks to you guys for your deep knowledge!
I happen to have the same setup of drivers and crossover apart from that my bassdriver is a Isophon 30/37A that has a higher sensitivity and is better match than the KEF. Japanese that are crazy about vintage UK speakers will pay you well for the Goodman Midax, Trebax and crossover network.
The Acousta vill give you little bass below 70-80 Hz and the shrill balance of the Lowther driver will make the sound even brighter. Look at DIY Loudspeaker Projects Troels Gravesen for measurements of the Lowther and similar speakers such as the Philips 9710.
If you want a more balanced horn go for the norwegian "the big fun horn". Or a simpler and much smaller build "the decca corner horn". I have a thread about this design that really is a Voigt pipe not a horn. Good bass down to 40-50 Hz and with the driver facing away from the listener that piercing high range is much more balanced. The design I built was the one published in HiFi News and Record Review more than 50 years ago.
The Acousta vill give you little bass below 70-80 Hz and the shrill balance of the Lowther driver will make the sound even brighter. Look at DIY Loudspeaker Projects Troels Gravesen for measurements of the Lowther and similar speakers such as the Philips 9710.
If you want a more balanced horn go for the norwegian "the big fun horn". Or a simpler and much smaller build "the decca corner horn". I have a thread about this design that really is a Voigt pipe not a horn. Good bass down to 40-50 Hz and with the driver facing away from the listener that piercing high range is much more balanced. The design I built was the one published in HiFi News and Record Review more than 50 years ago.
The tweeter may be a KEF T 15 rather than the Trebax.The crossover unit appears to be the Goodmans XO/950/5000.Perhaps the original system used the KEF 2.6 x 4'' elliptical midrange unit from the K1 Baffle arrangement and the Midax horn is a later replacement.If the cabinet has an internal volume of 80 litres or greater,then it could be used in a lash up with the Lowther after alterations to cover all the existing holes are made and also the fitting of a vent adjusted for a 40 Hz Fb. At the least,it will be possible to test if the PM6C will give you a satisfactory performance,as is,without going to the expense and complications of tuned pipe or backloaded horn enclosures which attempt to make up for a shortfall in the bass register by adding strong resonances and harmonics together with an obvious delayed energy content.
You will find the Lowther very bright and with a very directional high range
Lowther EX3
My 9710 has a similar response
Philips 9710/
And they sounded terrible in Lowther Accousta cabinets and far better in the Decca pipe.
Do start with the VaNarn suggested box but also try out the Lowthers facing you in the traditional orientation as well as aiming them backwards or upwards.
The tweeter does look like the KEF T15 not like the trebax on closer inspection.
Lowther EX3
My 9710 has a similar response
Philips 9710/
And they sounded terrible in Lowther Accousta cabinets and far better in the Decca pipe.
Do start with the VaNarn suggested box but also try out the Lowthers facing you in the traditional orientation as well as aiming them backwards or upwards.
The tweeter does look like the KEF T15 not like the trebax on closer inspection.
I have lowther pm 5a's , dx4's , dx65's
The horns you see are pm5a's in one cubic ft , front loaded horn.
They go up to about 12k and down to about 400hz.
I cross them over at 6k to knock 6db out of the shout , out
Tad 1602 on the bottom and a EV 30w below that.
A ring ratator tweeter above that.
Sounds wonderful. I could never see the reason to try to make a lowther make base , when the mids and highs are so detailed .I also see crossovers as the lesser of evils , for most speakers.
I know just another 2 cents in the buckett
thanks Ric
The horns you see are pm5a's in one cubic ft , front loaded horn.
They go up to about 12k and down to about 400hz.
I cross them over at 6k to knock 6db out of the shout , out
Tad 1602 on the bottom and a EV 30w below that.
A ring ratator tweeter above that.
Sounds wonderful. I could never see the reason to try to make a lowther make base , when the mids and highs are so detailed .I also see crossovers as the lesser of evils , for most speakers.
I know just another 2 cents in the buckett
thanks Ric
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Stewart Hegeman designed a Lowther based speaker for Harman Kardon, the Citation X. It was upward firing. Bass was provided by a specially designed split, slot-loaded back-horn.
I do not have the horn design he made for the Lowther, but I do have the drawings for a slot loaded conical horn he designed for EICO (their HFS-2 speaker, which used a Philips driver).
I bet someone here can adjust the design for your Lowther.
I do not have the horn design he made for the Lowther, but I do have the drawings for a slot loaded conical horn he designed for EICO (their HFS-2 speaker, which used a Philips driver).
I bet someone here can adjust the design for your Lowther.
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