next stage of driver tweaks
FT17H have gone in the cabinet, In the interests of laziness the 1uF capacitors are stuck on the back of the tweeters.
I've used neutrik 4 pole connectors and 4 core wiring, I can drag the amp out later and experiment with crossovers by splitting the wiring at the amplifier end. I'll relocate the capacitors then.
Summary of FE 207 E mods:
More blu-tac wrapped around the magnet, shaped for better airflow.
Bitumen and foil deadener applied to outside of basket legs.
4mm self adhesive felt stuck inside basket legs. smaller than the basket leg to ensure clearance for the rubber surround.
bits of felt stuck over the back of the magnet.
I've fiddled the photo to try to show the felt better.
Next: crossover and cone treatments, not sure what to go with, Mamboni/Enabl or the Planet 10 stepped thirds dammar pattern. Neither is reversible. should the dammar pattern be applied to the whizzer too?
I'm really interested in the Curvy Bruce cabinets too.
FT17H have gone in the cabinet, In the interests of laziness the 1uF capacitors are stuck on the back of the tweeters.
I've used neutrik 4 pole connectors and 4 core wiring, I can drag the amp out later and experiment with crossovers by splitting the wiring at the amplifier end. I'll relocate the capacitors then.
Summary of FE 207 E mods:
More blu-tac wrapped around the magnet, shaped for better airflow.
Bitumen and foil deadener applied to outside of basket legs.
4mm self adhesive felt stuck inside basket legs. smaller than the basket leg to ensure clearance for the rubber surround.
bits of felt stuck over the back of the magnet.
I've fiddled the photo to try to show the felt better.
Next: crossover and cone treatments, not sure what to go with, Mamboni/Enabl or the Planet 10 stepped thirds dammar pattern. Neither is reversible. should the dammar pattern be applied to the whizzer too?
I'm really interested in the Curvy Bruce cabinets too.
Attachments
hi,
well I'm quite interested on what you are doing with FE207 speakers as ntusI did my 207's on bass reflex cabinet with Aurum Cantus super tweeters G2i.
I play them with DIY amp solid state from pcpaudio.com
They sound nice and smoothe, but somehow I miss the beat in some rock pop music, not to mention electronic music. But It sometimes depends on the recording. I can listen to very bad jazz recordings, and I can listen to very good Depeche Mode classics. I don't know much, because I'm quite newbie with DIY world, and I get advice here and there, but it's very strange alltoghether: One year back I wouldn't bother at all about speakers, I would go for the od comercial speakers and that's it. Now I listen... but I enjoy it!!
It has been lately that may be I should change them to a "4 Wheel drive", as we say here in Spain. Something that you can drive elsewhere... that you can play with any music sounding great.
I was planning to add a subwoofer with active amp, but then I thoght that it would be a good idea to give a try to phase plugs and dammar varnishing. What do you think about the phase plugs changes? are they really worth them?
Have you tryed the Dammar allready?
At a point I was thinking to change completely my DIY speaker system into a 2 way kit. Still, I like my speakers and I'm shore that they can improve.
thanks
well I'm quite interested on what you are doing with FE207 speakers as ntusI did my 207's on bass reflex cabinet with Aurum Cantus super tweeters G2i.
I play them with DIY amp solid state from pcpaudio.com
They sound nice and smoothe, but somehow I miss the beat in some rock pop music, not to mention electronic music. But It sometimes depends on the recording. I can listen to very bad jazz recordings, and I can listen to very good Depeche Mode classics. I don't know much, because I'm quite newbie with DIY world, and I get advice here and there, but it's very strange alltoghether: One year back I wouldn't bother at all about speakers, I would go for the od comercial speakers and that's it. Now I listen... but I enjoy it!!
It has been lately that may be I should change them to a "4 Wheel drive", as we say here in Spain. Something that you can drive elsewhere... that you can play with any music sounding great.
I was planning to add a subwoofer with active amp, but then I thoght that it would be a good idea to give a try to phase plugs and dammar varnishing. What do you think about the phase plugs changes? are they really worth them?
Have you tryed the Dammar allready?
At a point I was thinking to change completely my DIY speaker system into a 2 way kit. Still, I like my speakers and I'm shore that they can improve.
thanks
Phase plugs work miracles. do it! do it! do it!
No cone treatments yet. I'm looking closely at the Mamboni/EnaBL thread in Loudspeakers.
I tried out an EL34 push-pull tube amp. WOW. Bottom end much better now. Try adding a couple of ohms in series with your speaker cable.
I'm building new cabinets soon. "Curvy Chang" thread. The way my room is arranged I can't corner load both of the singulars, the image is skewed to the right in the low end.
Crossover is simply a high pass for the tweeter, I tried a 12dB/octave LR type. Both with and without attenuation for the tweeter it was terrible.
I now have 4x33ohm wirewound in parallel for a cheap way to make a low inductance 8ohm resistor. This reduces the level of the tweeter by 3dB to match the efficiency of the FE207E.
Then I started with 1uF, then 0.47, 0.68 and I finished up with 0.57uF.
No cone treatments yet. I'm looking closely at the Mamboni/EnaBL thread in Loudspeakers.
I tried out an EL34 push-pull tube amp. WOW. Bottom end much better now. Try adding a couple of ohms in series with your speaker cable.
I'm building new cabinets soon. "Curvy Chang" thread. The way my room is arranged I can't corner load both of the singulars, the image is skewed to the right in the low end.
Crossover is simply a high pass for the tweeter, I tried a 12dB/octave LR type. Both with and without attenuation for the tweeter it was terrible.
I now have 4x33ohm wirewound in parallel for a cheap way to make a low inductance 8ohm resistor. This reduces the level of the tweeter by 3dB to match the efficiency of the FE207E.
Then I started with 1uF, then 0.47, 0.68 and I finished up with 0.57uF.
OzMikeH said:
Note that what you describe is not the 98 cent trick, but a variation. The original trick involves cutting a thin strip of low density foam (furnace filter foam in the original) and bracing the outer lip of the whizzer against the main cone.
(i have an illustration & pictures on my other 'puter if you want me to post them)
dave
Dave:
please post the pics here. A few people will be using this driver in the Changs soon so here might be a good place to collect such things. I searched for the 98c mod and I couldn't find anything.
Furnace filter will be impossible to get, Air conditioner filter is very common though.
H.G.:
It was ok on my SS amp which has extremely low output impedance. Really not the right amp for these speakers. They sound nicer with extremely thin speaker wire or a tube amp.
When I tried it on a tube amp it distorted badly at high volumes around 10k. I suspect from a low impedance at the crossover range because it was an overdriven tube sounding distortion.
It was a very simple crossover, the FE207E is 16 ohms at 10kHz, so I used parallel 0.5uF capacitance with a series inductor somewhere around 0.5mH (I can't remember the value, I bought a big inductor and removed turns until I had what I needed)
The tweeter was 8 ohms with a series 1uF and a similar (not the same ) inductor in parallel. After that was a couple of resistors to reduce the level 3dB while maintaining the 8 ohms impedance.
The 6dB/octave filter I have now should have a flatter impedance with both drivers, the increasing impedance of the FE207E with frequency and the 8 ohm tweeter with 8 ohms in series (16 ohms again) coming in with frequency should make for a nice impedance for the amplifier.
I need to get my test equipment organised. someone should sell a Wallin Jig kit to save time searching for all of those parts.
please post the pics here. A few people will be using this driver in the Changs soon so here might be a good place to collect such things. I searched for the 98c mod and I couldn't find anything.
Furnace filter will be impossible to get, Air conditioner filter is very common though.
H.G.:
It was ok on my SS amp which has extremely low output impedance. Really not the right amp for these speakers. They sound nicer with extremely thin speaker wire or a tube amp.
When I tried it on a tube amp it distorted badly at high volumes around 10k. I suspect from a low impedance at the crossover range because it was an overdriven tube sounding distortion.
It was a very simple crossover, the FE207E is 16 ohms at 10kHz, so I used parallel 0.5uF capacitance with a series inductor somewhere around 0.5mH (I can't remember the value, I bought a big inductor and removed turns until I had what I needed)
The tweeter was 8 ohms with a series 1uF and a similar (not the same ) inductor in parallel. After that was a couple of resistors to reduce the level 3dB while maintaining the 8 ohms impedance.
The 6dB/octave filter I have now should have a flatter impedance with both drivers, the increasing impedance of the FE207E with frequency and the 8 ohm tweeter with 8 ohms in series (16 ohms again) coming in with frequency should make for a nice impedance for the amplifier.
I need to get my test equipment organised. someone should sell a Wallin Jig kit to save time searching for all of those parts.
oh that stuff, I have heaps. By hand pick do you mean starting with a chunk and plucking bits off until it's the right shape?
Tip: an electric carving knife is perfect for shaping foam. You can quickly cut bits to make anechoic panels that way too.
I never thought I'd say this but: that speaker is way too "loud" for me.
Tip: an electric carving knife is perfect for shaping foam. You can quickly cut bits to make anechoic panels that way too.
I never thought I'd say this but: that speaker is way too "loud" for me.
OzMikeH said:
By hand picked i mean i pick the lowest desity foam from my stash of 100s of pieces of foam.(that is also the appropriate thickness -- 5-10mm)
I cut it with scissors.
Those are the heart of a system i put together for my 20 month old god-son (gotta start em early). A true frugal-phile(tm) speaker... drivers were $18 CAD (and finishing materials doubled that). Built on the carcass of a set of KEF Calindas (the woofers & PRs are now in Oz)
dave
Attachments
With regards to the crossover, I just wired a 0.33uF to the positive terminal of the FT17H and wire it in parallel to a FE-206.
Might be able to ditch the resistors if you crossover higher, let the natural 6db rollover do the attenuation.
At this point, sounds from the tweeters are just cymbals and triangles.
But i suspect the crossover affects the 206 in a positive way too sounds clearer with the supertweeter attached
Might be able to ditch the resistors if you crossover higher, let the natural 6db rollover do the attenuation.
At this point, sounds from the tweeters are just cymbals and triangles.
But i suspect the crossover affects the 206 in a positive way too sounds clearer with the supertweeter attached
I tried that, The rising response of the tweeter is too much for me. My hearing is good to 19kHz and is particularly sensitive around 16kHz. As part of my job I was trained to fine tune radio receiver filters by ear. In some ways this is unfortunate, it means I need more effort for a sound I am happy with.
There is a lot of information up there also from the breathing, ffff and ssss in female vocals.
The FE207 is very different to the 206 in the high end. it starts to run out at 12kHz,
The effect on the 206 from the tweeter will vary with amplifier type. lower impedance with rising frequency will pull the voltage down on certain amps. On a SS amp that is happy into very low impedances it won't make noticeable difference.
You can test your theory, put an 8 ohm resistor in place of the FT17H. A/B it with and without the resistor and capacitor.
There is a lot of information up there also from the breathing, ffff and ssss in female vocals.
The FE207 is very different to the 206 in the high end. it starts to run out at 12kHz,
The effect on the 206 from the tweeter will vary with amplifier type. lower impedance with rising frequency will pull the voltage down on certain amps. On a SS amp that is happy into very low impedances it won't make noticeable difference.
You can test your theory, put an 8 ohm resistor in place of the FT17H. A/B it with and without the resistor and capacitor.
Hi guy's, I have the MLTL's with the 207/17H combination and I just dropped the tweeter in with 8 ohms and a 0.57uf cap (approx.)
The thing is that I already had a series resistor on the FE207E to bring the base alive and I just left it there.
I've been playing with this for some time and need some technical input on how to calculate the resistors on this set up....
Or do I even need the series resistor anymore?? Need help!
It just doesn't seem right......
The thing is that I already had a series resistor on the FE207E to bring the base alive and I just left it there.
I've been playing with this for some time and need some technical input on how to calculate the resistors on this set up....
Or do I even need the series resistor anymore?? Need help!
It just doesn't seem right......
Attachments
None whatsoever
The inputs are filtered for mids/bass or treble so I dont have to do anything with the outputs at all.
However, I forgot.... there is some series resistance on the 207's to bring up the base a bit. I soldered up some cables with Nichrome wire in them rather than dropping a resistor in there so I cant fully remember what the value was that I ended up with
.... it's about 5 ohms I think.
regards
Lee
The inputs are filtered for mids/bass or treble so I dont have to do anything with the outputs at all.
However, I forgot.... there is some series resistance on the 207's to bring up the base a bit. I soldered up some cables with Nichrome wire in them rather than dropping a resistor in there so I cant fully remember what the value was that I ended up with
.... it's about 5 ohms I think.regards
Lee
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