Op-amps like TL072 etc are cheap enough, allowing active crossovers to be made cheaply. The real problem is finding out what the crossover should actually be. You can do it by ear if you have a digital crossover (because it allows instant changes of crossover frequency, equalisation etc). With op-amps, you need a measurement system (probably based on a soundcard), and lots of patience. Of course, this all assumes that you have three stereo amplifiers...
Still, that's for the future. Good luck building the new cabinets.
Still, that's for the future. Good luck building the new cabinets.
You're welcome. I always think a bit of politeness goes a long way. Oh, and welcome to the forum - hope you like it here.
HiFi Answers article
Hi Dave (Planet 10) I'd be grateful if you would send me a copy (.pdf) of the HiFi Answers article on building the R50s. Thanks, Roy
Hi Dave (Planet 10) I'd be grateful if you would send me a copy (.pdf) of the HiFi Answers article on building the R50s. Thanks, Roy
I have a pair of the Pro-9TL mk1's and my dad has pair of the mk2's that he built a long time ago 😀 They've both had replacement vifa D27TG tweeters on falcon's recommendation.
The mk2's seem go much lower than the original and sound tighter, mine seem to require a large room to give good output. The mk2's also look a lot better!😎
The mk2's seem go much lower than the original and sound tighter, mine seem to require a large room to give good output. The mk2's also look a lot better!😎
Hi,
What is the difference between the Pro9-TL Mk1 and Mk2, please?
As I recall, Chris J. Rogers only published one version, the one you could still buy at Falcon until recently.
Regards
Wieslaw
What is the difference between the Pro9-TL Mk1 and Mk2, please?
As I recall, Chris J. Rogers only published one version, the one you could still buy at Falcon until recently.
Regards
Wieslaw
Reffering to the pdf's posted by planet10. From what I understand, the 'mk1' is a clone of the Cambridge Audio R50, published in HiFi answers magazine; whereas the 'mk2' is the refined system sold from falcon.
Chris Rogers designed them both. The 1st a 4-way with a mid-range enclosure, the 2nd with no midrange enclosure, one less driver, and one less fold. The 2nd article (Falcon one) describes why the updates.
If one to were to do a B139 TL today, you might be better with one designed using MJK. Attached is a triangulated TL Scott & i did -- if you find the TTL a daunting construction then it could easily be rejigged for rectangular cross-section.
dave
If one to were to do a B139 TL today, you might be better with one designed using MJK. Attached is a triangulated TL Scott & i did -- if you find the TTL a daunting construction then it could easily be rejigged for rectangular cross-section.
dave
Attachments
Hi Dave,
Thankyou very much for the Pro9TL MkII PDF.
Boy did that bring back a flood of great memories.
I used to live not far from "Badger Sound Services Ltd" when I was 18 (1979) and in fact still have my original Thorens TT that I bought from them just before returning to New Zealand. (still in use today)
Bagers used to have a rough MDF pair of Pro9's that were demonstraters and when ever my parents were out of town my mates and I would go and load the Pro9's in the back of the Viva estate and set them up for the weekend at our semi house in Blackpool much to the neighbours delite!!!
Trio amp, Pioneer tape deck, beloved Thorens and Pro9's TL.
We had a ball usually with a not insignificant amount of alcohol if I remember correctly. Also blew up a midrange in one I recall. More to do with Trio amp cllipping I think. I remember crapping myself about telling them when I returned them. He just shrugged his shoulders and said oh well and plugged another one in and of we went.
Anyway I remember them as being my ultimate speaker and if I could find a good pair I would definately consider buying them today.
It would be interesting to see how they would rate in todays world of computor aided design and measurements. Surely given the advancements in technologies and our understandings of the finer points of speaker designs these days we could come up with (probably have) a similar design that out performs them in all regions.
Perhaps we should (the group) come up with a modern updated version!! Any takers?
For those that are interested I can't tell you about imaging. sound stage or any of that stuff but they did sound great and most of my mates agreed. They did need a bit of driving to get the best out of them though.
Regards
Ian
Thankyou very much for the Pro9TL MkII PDF.
Boy did that bring back a flood of great memories.
I used to live not far from "Badger Sound Services Ltd" when I was 18 (1979) and in fact still have my original Thorens TT that I bought from them just before returning to New Zealand. (still in use today)
Bagers used to have a rough MDF pair of Pro9's that were demonstraters and when ever my parents were out of town my mates and I would go and load the Pro9's in the back of the Viva estate and set them up for the weekend at our semi house in Blackpool much to the neighbours delite!!!
Trio amp, Pioneer tape deck, beloved Thorens and Pro9's TL.
We had a ball usually with a not insignificant amount of alcohol if I remember correctly. Also blew up a midrange in one I recall. More to do with Trio amp cllipping I think. I remember crapping myself about telling them when I returned them. He just shrugged his shoulders and said oh well and plugged another one in and of we went.
Anyway I remember them as being my ultimate speaker and if I could find a good pair I would definately consider buying them today.
It would be interesting to see how they would rate in todays world of computor aided design and measurements. Surely given the advancements in technologies and our understandings of the finer points of speaker designs these days we could come up with (probably have) a similar design that out performs them in all regions.
Perhaps we should (the group) come up with a modern updated version!! Any takers?
For those that are interested I can't tell you about imaging. sound stage or any of that stuff but they did sound great and most of my mates agreed. They did need a bit of driving to get the best out of them though.
Regards
Ian
I used a pair of Badgers Compact Monitors, which were a chopped down closed box, Pro9 using an Audax 10in bass. The mid / tweeter and XO were the same. A friend still uses the " 9's ", at least for now.
The biggest sorce of irritation was the Peerless mid on both speakers. After a few months I started to tire of them, sounding somewhat compressed and box bound. If you listened to them in isolation, with XO, they sounded just like a small portable radio. A similar test with B110 ( in small box ), the latter always sounded vastly better. That is the problem with the Peerless, the tiny rear enclosure which strangles the sound.
Having a number of discussions with Badger at the time, they were in agreement about the Peerless and were even thinking of cutting the back off and using a larger enclosure. In the end they used a TDL mid unit, basically reverting back to the Rodgers layout.
The friend with the Pro 9, has been experimenting with a small seperate, open baffle, using an Audax 130 mid and the original tweeter. This is placed on top of the TLine, with the 139 acting basically as a subwoofer. He has phoned me several times saying how shocked he has been over how much information he has been loosing ( trying to tell him for years ). Even with a basic XO he say it all sounds vastly more open and dynamic.
So if you do try a TL with 139 ( this has its problems as discribed elsewhere ) avoid the KO40. If you want a classic design I would stick with the B110 if you can find a pair. There are good alternatives available e.g, Monacor
The biggest sorce of irritation was the Peerless mid on both speakers. After a few months I started to tire of them, sounding somewhat compressed and box bound. If you listened to them in isolation, with XO, they sounded just like a small portable radio. A similar test with B110 ( in small box ), the latter always sounded vastly better. That is the problem with the Peerless, the tiny rear enclosure which strangles the sound.
Having a number of discussions with Badger at the time, they were in agreement about the Peerless and were even thinking of cutting the back off and using a larger enclosure. In the end they used a TDL mid unit, basically reverting back to the Rodgers layout.
The friend with the Pro 9, has been experimenting with a small seperate, open baffle, using an Audax 130 mid and the original tweeter. This is placed on top of the TLine, with the 139 acting basically as a subwoofer. He has phoned me several times saying how shocked he has been over how much information he has been loosing ( trying to tell him for years ). Even with a basic XO he say it all sounds vastly more open and dynamic.
So if you do try a TL with 139 ( this has its problems as discribed elsewhere ) avoid the KO40. If you want a classic design I would stick with the B110 if you can find a pair. There are good alternatives available e.g, Monacor
Roy Lewis said:
That's not a good recommendation for the Peerless units. The B110 has always been one of my least favourite drivers! 🙂
pinkmouse said:
Yes, that is how we heard it the, Peerles always seemed congested. I agree with " Planet 10 " on post 15, " not up to the best of today, but quite good ".
In 1982, Dave Berriman did a small bookshelf speaker the " DBS5 " in an magazine called Practical HiFi ( still got the mag ) This used the B110 and scanspeak tweeter. The crossover was 1st for 110, 2nd for Scanspeak. For the 110 he used a large 2.4 air core inductor. I did a version of this for a friend but with an Audax tweeter ( he could not afford the Scan at the time ). It sounded excellent. To me the old Kef XO never sounded that good
I liked the B110. One of the most memorable speakers i did was a B110/T27 isobarik MTM (predating d'Appolito IIRC)... far from perfect, but very enjoyable.
dave
dave
Excuse me for diggin' up this thread,
but I find TL-design reviving again
At least at my house 🙂
But what I wanted to ask:
Well then, essentially, how ? 😀
Has anyone build the TTL ?
I was thinking of making a Pro-9 TL until I found this post by Planet10....
Oh, and how about mating a B139-TL to a full-range driver like the Hemp FR8c ? and topping that off with a ribbon tweet,
so using the Hemp for extended mid-range ? (thinking 100Hz - 5000Hz)
Hope to get some constructive criticism 😉
Cheers,
Empee
but I find TL-design reviving again
At least at my house 🙂
But what I wanted to ask:
planet10 said:
Well then, essentially, how ? 😀
Has anyone build the TTL ?
I was thinking of making a Pro-9 TL until I found this post by Planet10....
Oh, and how about mating a B139-TL to a full-range driver like the Hemp FR8c ? and topping that off with a ribbon tweet,
so using the Hemp for extended mid-range ? (thinking 100Hz - 5000Hz)
Hope to get some constructive criticism 😉
Cheers,Empee
I have an idea for the r50, I would like to place the vent of the tl below the base unit, so the tl line would be in effect upside down, this is so I can get the base unit closer to the midrange, as i have never been to keen on the vent being between the base and mid, the measurements for the cabinets I have in mind is roughly H 1270mmx W 360mmx D 460mm, I would be greatful for any suggestions, thankyou.
I built a pair of the HI Fi Answers R50 rip-off in the 70's and subsequently made new baffle boards because the speaker units appeared to be too far apart - a rising glissando from an orchestra's violin section gave the impression that it was floating upwards! I submitted the mod and it was published (earned me a whole year's free subscription;-) and I received positive feedback from others who applied the changes. Nothing as drastic as moving the TL port below the 139. The oblong port became a round port beside the lowered 110 and the tweeters moved down and sat beside one another above the 110; the baffles were mirrored right and left. The other modification was to remove the flanges formed by the front side edges of the cabinet so that they were flush with the baffle. This kept the violin sections firmly seated at all times! If anyone was going to play around with the design today I don't think two tweeters are any longer necessary - today's scandinavian offerings more than exceed the T27 and 4001's combined ability.
Today there are small extended full-ranges that easily substitute for B110/T27/4001 with better performance thru-out the range. Many of those also let you push the XO down to ~ bafflestep, and bi-amped lets you throw away the passive XO.
dave
This is an interesting thread as I have a pair of IMF Pro Monitor IIIs in need of repair. I have the IMF TW 2100F super tweeters in mine and both are beyond repair so I considered replacing the Celestion HF1300s and the IMF tweeters with a single pair of Vifa or ScanSpeak tweeters. My only concern is the crossover and any alterations I may have to make to it.
Incidentally I did try to contact you for your advice Planet10 but to no avail. Replacing all three drivers ie the B110 as well is a very interesting thought though I don't think I'm prepared to go that far just yet.
Incidentally I did try to contact you for your advice Planet10 but to no avail. Replacing all three drivers ie the B110 as well is a very interesting thought though I don't think I'm prepared to go that far just yet.
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