I had I think an early pair of these years back with the sandpaper finished bass drivers. I never had them apart but would you describe these as a bass reflex design with a rectangular cross section port? The letter box hole in the baffle and being IMF inferred to me they were a transmission line design unfortunately none of your video showed the port entrance within the cabinet (the opposite end from the baffle). The internal pics look like the cabinet is full depth which infers the top of the port doesn’t go fully back to the rear panel. Is this correct? Keep up the great work, KJ
I wouldn't call them transmission line. It is like you described. A letterbox port that runs full width and finishes about 50mm from the back. No port noise from anything that wide. A nice sounding speaker actually. Enjoyable
@@RWL2012 from memory, (it’s been many many years since I had mine) the foam looked like it would pass air though how restrictive it was I don’t know. Modern t/l (which this is not) use foam in the transmission path to slow the air (like PMC I believe) . To me I’ve never really got how there is no “overhang” from any speaker that’s not an infinite baffle design. I you take bass a bass drum sound propelling the driver forward then on its return path it must be firing the same volume of air backwards (unless it compresses it) which travels the transmission line and eventually out the port. Is that air out of phase with the original output or is it delayed or both?
Hello, thank you for your video, it's great. I'm currently restoring the same model and I would like to know what is the model of the two wire wound resistors you used to replace the old ones? You say : 10 Watt metal oxide resistors 5 watt rated ??? what ohm ?
Watch all the way through and you'll see at 16.09 I put up the schematic of what I did. There is a 4.7ohm and 3.3ohm mox resistor used on the tweeter circuit. A 15ohm on the midrange
@@haycrossaudio5474 Thank you for your prompt response. Unfortunately, I am not an electronics expert and I do not know how to read an electronic schematic. I wanted to know if I can send you an email with a picture of my board because I do not know the values of the resistors. Additionally, I wanted to know if I can just change the two resistors. Regards, Arie
@@ArielFigueroaSaintard I think you need someone to help you. Unfortunately I don't have time to go back and forth with emails. Watch the videos in detail. Hopefully they will help
No, this is not a transmission line as you would need a quarter wave distance for bass reinforcement. This is closer to a Dynaco a 25 speaker. Not quite a base, reflects or sealed cabinet, a tuned pressure relief. Someone who has more information on this please post.
@@haycrossaudio5474 I'm quite lost for words on the difference you have made, how fantastic that it can be measured, seen, and most importantly heard! All the work you put in, 13 sanding disks really! 🤣.
I had I think an early pair of these years back with the sandpaper finished bass drivers. I never had them apart but would you describe these as a bass reflex design with a rectangular cross section port? The letter box hole in the baffle and being IMF inferred to me they were a transmission line design unfortunately none of your video showed the port entrance within the cabinet (the opposite end from the baffle). The internal pics look like the cabinet is full depth which infers the top of the port doesn’t go fully back to the rear panel. Is this correct?
Keep up the great work, KJ
I wouldn't call them transmission line. It is like you described. A letterbox port that runs full width and finishes about 50mm from the back. No port noise from anything that wide. A nice sounding speaker actually. Enjoyable
It doesn't make sense how the ports are blocked by foam though.
@@RWL2012 from memory, (it’s been many many years since I had mine) the foam looked like it would pass air though how restrictive it was I don’t know. Modern t/l (which this is not) use foam in the transmission path to slow the air (like PMC I believe) .
To me I’ve never really got how there is no “overhang” from any speaker that’s not an infinite baffle design. I you take bass a bass drum sound propelling the driver forward then on its return path it must be firing the same volume of air backwards (unless it compresses it) which travels the transmission line and eventually out the port. Is that air out of phase with the original output or is it delayed or both?
Hello, thank you for your video, it's great. I'm currently restoring the same model and I would like to know what is the model of the two wire wound resistors you used to replace the old ones? You say : 10 Watt metal oxide resistors 5 watt rated ??? what ohm ?
Watch all the way through and you'll see at 16.09 I put up the schematic of what I did. There is a 4.7ohm and 3.3ohm mox resistor used on the tweeter circuit. A 15ohm on the midrange
@@haycrossaudio5474 Thank you for your prompt response. Unfortunately, I am not an electronics expert and I do not know how to read an electronic schematic. I wanted to know if I can send you an email with a picture of my board because I do not know the values of the resistors. Additionally, I wanted to know if I can just change the two resistors. Regards, Arie
@@ArielFigueroaSaintard I think you need someone to help you. Unfortunately I don't have time to go back and forth with emails. Watch the videos in detail. Hopefully they will help
@@haycrossaudio5474 ok thanks you, last question if i replace only 2 mox resistors 15ohm that's working ?
Is the tweeter an inverted dome? Hard to tell.
No not inverted. Made by Audax
They look like the Deacy amp/speaker Brian May from queen uses.
No, this is not a transmission line as you would need a quarter wave distance for bass reinforcement. This is closer to a Dynaco a 25 speaker. Not quite a base, reflects or sealed cabinet, a tuned pressure relief. Someone who has more information on this please post.
@@SuperMcgenius No its not a transmission line. Its just a rectangular folded port. Resistive reflex
@ in my late teens, I had a pair of IMF tls 50’s, Not perfect, but better than most of the time.
Those be rosewood cabinets :)
That was the word I was looking for 🤣
@@haycrossaudio5474 I'm quite lost for words on the difference you have made, how fantastic that it can be measured, seen, and most importantly heard! All the work you put in, 13 sanding disks really! 🤣.
I had those when I was young. I gave them away to somebody who left them in his car overnight. They got stolen....
Oh no. There really nice speakers