Hi all,
I've been lurking around here for a fair while trying to absorb information with a view to building myself some full range speakers, but have decided I might be better starting my attempts somewhere simpler. With that in mind, I thought about upgrading my RTL3s (I have the later Special Edition models). I've enjoyed these for a good few years, but have always thought that they don't cope with modern, more bassy, music particularly well ...tending to get a bit 'flabby'.
Has anyone any experience or suggestions for a suitable driver upgrade that will tighten them up? I should probably mention that the amp that I use is a Marantz PM7200 KI signature.
...any advice would be appreciated.
Bob
I've been lurking around here for a fair while trying to absorb information with a view to building myself some full range speakers, but have decided I might be better starting my attempts somewhere simpler. With that in mind, I thought about upgrading my RTL3s (I have the later Special Edition models). I've enjoyed these for a good few years, but have always thought that they don't cope with modern, more bassy, music particularly well ...tending to get a bit 'flabby'.
Has anyone any experience or suggestions for a suitable driver upgrade that will tighten them up? I should probably mention that the amp that I use is a Marantz PM7200 KI signature.
...any advice would be appreciated.
Bob
The problem with big transmission lines, which go deep, is you usually don't have a room big enough to stop them booming! 
The specs are roughly as follows:
Technical Specifications
RTL3
Reflex transmission line loading floor standing
Two 172 mm loaded polypropylene cone with forward roll rubber surround & phase plug - long throw double wound coil on kapton former with bump back magnet yoke.
19mm soft dome ferro-fluid cooled
Electrical 2 way second order network
35hZ-20kHz
90dB at 1m for 1 watt
8 ohm nominal
20-120 watts per channel
900mm wide x 375mm deep
Black ash or rosewood
21Kg each
The 2nd order crossover is a bit odd IMO, with a resistive shunt across the basses, Looks like the basses are wired in parallel, but it would be a heck of a job to redesign it, though I'd start with a 5kHz notch on the basses.
Excellent info here on the RTL3 model.
Creating a new MTM Floorstanding speaker using the drivers from the TDL RTL3.
A metal dome tweeter might be a slot in replacement for the soft dome. What size is the cutout?
The specs are roughly as follows:
Technical Specifications
RTL3
Reflex transmission line loading floor standing
Two 172 mm loaded polypropylene cone with forward roll rubber surround & phase plug - long throw double wound coil on kapton former with bump back magnet yoke.
19mm soft dome ferro-fluid cooled
Electrical 2 way second order network
35hZ-20kHz
90dB at 1m for 1 watt
8 ohm nominal
20-120 watts per channel
900mm wide x 375mm deep
Black ash or rosewood
21Kg each
The 2nd order crossover is a bit odd IMO, with a resistive shunt across the basses, Looks like the basses are wired in parallel, but it would be a heck of a job to redesign it, though I'd start with a 5kHz notch on the basses.
Excellent info here on the RTL3 model.
Creating a new MTM Floorstanding speaker using the drivers from the TDL RTL3.
A metal dome tweeter might be a slot in replacement for the soft dome. What size is the cutout?
Thanks for your responses.
So I'm sensing there might not be that much to gain from messing with the RTL3s, or at least, no certainty of much gain for what could be more effort than I had first thought. As Inductor suggests, maybe I should start from scratch, although I think that may be a bit beyond me at the moment. Perhaps a kit, or at least a tried and tested formula? To be honest, that was mostly why I had originally thought of building full range speakers as a starting point ...a relatively simple and tried and tested build (such as the Frugal horns), albeit with a more complex cabinet design (which would not be a problem for me). But the more I've read, the more it seems to get good bass from fullrange you need mahoosive cabinets.
By the by, the room size thing is probably very pertinent, as when I first had the TDLs they were in a pretty large living space compared to now, and I don't remember thinking there was a problem with them then.
So I'm sensing there might not be that much to gain from messing with the RTL3s, or at least, no certainty of much gain for what could be more effort than I had first thought. As Inductor suggests, maybe I should start from scratch, although I think that may be a bit beyond me at the moment. Perhaps a kit, or at least a tried and tested formula? To be honest, that was mostly why I had originally thought of building full range speakers as a starting point ...a relatively simple and tried and tested build (such as the Frugal horns), albeit with a more complex cabinet design (which would not be a problem for me). But the more I've read, the more it seems to get good bass from fullrange you need mahoosive cabinets.
By the by, the room size thing is probably very pertinent, as when I first had the TDLs they were in a pretty large living space compared to now, and I don't remember thinking there was a problem with them then.
The issue with these speakers seems to be whether they have Monacor SPH-175 polys or paper Visaton WS17E.
The latter is used in a published design, an MMT called the CLOU:
CLOU
You need to dissect and measure the crossover. Very little can be done without a schematic. Once that is done, this gets easier.
I'd like to know what is going on with the cabinet construction too, which is mainly a reflex by the look of it. Really, how much help you get depends on supplying some good info. Vikash seems a good man and did good measurements, but not a crossover expert. He could have done better, IMO.
The latter is used in a published design, an MMT called the CLOU:
CLOU
You need to dissect and measure the crossover. Very little can be done without a schematic. Once that is done, this gets easier.
I'd like to know what is going on with the cabinet construction too, which is mainly a reflex by the look of it. Really, how much help you get depends on supplying some good info. Vikash seems a good man and did good measurements, but not a crossover expert. He could have done better, IMO.
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They look more like the Visiton, although they have a phase plug ...shame really, seeing as they're priced at around £17 online rather than the £50 or so for the Monacors. That suggests my TDLs might be an inferior version. Which also begs the question,and I apologise if this is a really stupid question, but would replacing the drivers with the Monacors in itself be an upgrade/improvement?
Don't make the mistake of thinking price has anything to do with sound quality. It's quite possible the Visatons sound better than the Monacors.
Bob, you should be able to tell polypropylene from paper cones just by looking at them and touching them. Plastic is shiny stuff like plastic detergent bottles, paper is, well, cardboardy like your cornflake packet.
We are still stuck at the starting gate here...
Photos might help.
And, yes, Mr. Marley is right, price is no indication of quality really. You can do a lot with a good crossover. My favourite Visaton TW 70 cone tweeter costs just £10.
We are still stuck at the starting gate here...
Photos might help.
And, yes, Mr. Marley is right, price is no indication of quality really. You can do a lot with a good crossover. My favourite Visaton TW 70 cone tweeter costs just £10.
Ah but what if the cardboard is coated with plastic
.My considered opinion is that they're the Visatons ...they're the same as these in the pik (but my cabinets are oak finish).
Having read up a bit this evening on anything I could find, it would seem there are differing opinions as to whether these are variants of the Visaton W170 S or the WS 17 E drivers. On the off chance that I might get a reply, I've emailed Visaton to ask if they can clarify, but I think I'll go ahead with the Clou idea anyway, using these drivers, and see how it turns out
.
You haven't a clue really! They could be Elac units too.Ah but what if the cardboard is coated with plastic
My considered opinion is that they're the Visatons ...they're the same as these in the pik (but my cabinets are oak finish).
Now have a look at the back of the cones, they won't be coated with anything. Polypropylene is really quite distinctive shiny smooth stuff. Not as scratchy sounding as paper.
You haven't a clue really! They could be Elac units too.
Now have a look at the back of the cones, they won't be coated with anything. Polypropylene is really quite distinctive shiny smooth stuff. Not as scratchy sounding as paper.
Now here's a thing ...I've managed to locate specs for both the original RTL3s with the Monacor squared-off-edge drivers, and the special edition RTL3s (like mine), and both specify a polypropylene cone. The difference in the specs is the tweeter, which is 19mm for the early version, and 25mm for the special edition, also the frequency range goes down to 30hz for the latter, as opposed to 35hz.
Although not that relevant to this, I'm pretty sure the tweeters are Eltax item 03045.
I haven't got the speakers with me at the moment, they're in the workshop, but I'll take the drivers out first thing tomorrow and see if that sheds any light on things.
I's suggest that with these speakers, cleaning up the XOs, stuffening the cabinet, oprimizing damping, and driver tweaks would be as far as you want to go. All relatively low material costs, but lots of research & hand's on. Learn without spencing much.
Pictures of the drivers out of the box, the XO, and a few inside shots of the box would be helpful
dave
Pictures of the drivers out of the box, the XO, and a few inside shots of the box would be helpful
dave
Well, they're definitely polypropylene cones. No manufacturer's name (that would be too easy) but there is this on them... 172-NS-08.
There didn't seem a lot of point in photographing the crossovers, as without mullering them, all you can see is the underside of the circuit board ...the components are hidden between that and the the terminal plate thing.
I have to say, I'm amazed that these unimposing, even feeble, looking drivers manage to produce the amount of bass they do in those cabinets.
An externally hosted image should be here but it was not working when we last tested it.
An externally hosted image should be here but it was not working when we last tested it.
There didn't seem a lot of point in photographing the crossovers, as without mullering them, all you can see is the underside of the circuit board ...the components are hidden between that and the the terminal plate thing.
I have to say, I'm amazed that these unimposing, even feeble, looking drivers manage to produce the amount of bass they do in those cabinets.
That's good stuff, Bob. I think those are ELAC units. Probably similar to the 172 NS 05 which has a 34mm voice coil. Probably 7 ohms DC resistance if nominal 8 ohms, but worth measuring.
I get a Vas around 15L and a Qts around 0.44 and Fs 32Hz and 87dB sensitivity. Closed box drivers really. Will work in 10-20L if I haven't lost my touch.
Your crossover may be similar to Vikash's one on the bass part. But you have a 25mm tweeter rather than the feeble 19mm jobbie. What tweeter cutout and motor hole do you have? 94mm or maybe 104mm outer diameter?
I'd have to model that overheating 10R bass shunt to figure out a better way of doing it. But progress.
I get a Vas around 15L and a Qts around 0.44 and Fs 32Hz and 87dB sensitivity. Closed box drivers really. Will work in 10-20L if I haven't lost my touch.
Your crossover may be similar to Vikash's one on the bass part. But you have a 25mm tweeter rather than the feeble 19mm jobbie. What tweeter cutout and motor hole do you have? 94mm or maybe 104mm outer diameter?
I'd have to model that overheating 10R bass shunt to figure out a better way of doing it. But progress.
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Well a swift google of Elac 172 NS 08 and (ta-da) this pops up quick as you like! So the whole Visaton thing's just a massive red herring ...amazing how there's so much written out there pointing to them.
The tweeter hole is 79mm with the recess at 100mm, and (if you need it) the hole for the driver is 150mm.
Bob
The tweeter hole is 79mm with the recess at 100mm, and (if you need it) the hole for the driver is 150mm.
Bob
I've spent a bit of time this morning trawling what I could find on the net in the hope of finding a scheme specifically for the 'special edition' crossover. The only thing I've been able to discern for sure is that what made them 'special edition' was an upgraded crossover and tweeter (as well as better quality internal cabling ...oh, and gold coloured screws for the drivers!).
I haven't mentioned that I also have a pair of RTL1s. These I bought in the mid nineties, if I remember correctly, and it was the fact that I liked these so much that led me to eventually get hold of their bigger brothers when I was looking for a new pair of floorstanders years later. They're not badged as SE, but have the same drivers and overall cosmetic appearance ...rounded bottoms to speaker grills etc.
I know the crossovers are going to be different, only having the one woofer, but I would be prepared to risk wrecking these crossovers to see how they're constructed if it could be helpful. I can't get hold of them for a day or so, as they're currently in storage following a recent move, when I do I'll check to see if they have the same tweeters as the SEs.
I did find this listing/info on hebay (of all places) which I think might be worth a link.
I haven't mentioned that I also have a pair of RTL1s. These I bought in the mid nineties, if I remember correctly, and it was the fact that I liked these so much that led me to eventually get hold of their bigger brothers when I was looking for a new pair of floorstanders years later. They're not badged as SE, but have the same drivers and overall cosmetic appearance ...rounded bottoms to speaker grills etc.
I know the crossovers are going to be different, only having the one woofer, but I would be prepared to risk wrecking these crossovers to see how they're constructed if it could be helpful. I can't get hold of them for a day or so, as they're currently in storage following a recent move, when I do I'll check to see if they have the same tweeters as the SEs.
I did find this listing/info on hebay (of all places) which I think might be worth a link.
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