taming harshness of fostex FF125WK

Status
This old topic is closed. If you want to reopen this topic, contact a moderator using the "Report Post" button.
I applied the zig 2-way glue yesterday and repeated the measurement today.
Below is an overlay of the two waterfall plots.
Blue is before treatment
Green is after treatment

We can see an 8db lower resonance at 150ms at 6.7khz which tends to indicate that the treatment does work :)

Furthermore, it seems the trough following the resonance has disappeared.

I'll be doing some listening later tonight to see how this translates into real world listening.

Regards
Nick
 

Attachments

  • ff125wk close mic waterfall overlay.jpg
    ff125wk close mic waterfall overlay.jpg
    176.8 KB · Views: 474
Last edited:
It's not THAT bad. They are actually pretty good up to 4K with a steep enough crossover.

I didn't say it was. I said that the majority of the 127's output above ~1.5KHz is by means of resonant action. That's how wideband drivers work (the transition frequency varying depending on the unit it question of course)
 
Last edited:
think of the driver as not acting like a flat plate anymore above a certain frequency. Now sound is radiating from wedges, and eventually like random pillars of frequencies leaving the cone.

Cascasde Technology

Conjecture; probably well founded. This is why I said a long time ago, we are just guessing and experimenting without laser inferometrery to actually see what is happening. I think more of what the doping is trying to modify is the internal resonances within the cone, not so much it's non-piston behavior. Spread out the resonances and lower their Q so no peak dominants the intended signal.

The doping process works well enough I applied it to an RS-150 on the back only at the surround and spider. It would allow one order shallower crossover. I did just the dustcap on my Fountek's and it took a nasty edge off them.

Do you lose high end? Well, you lose some of what was not in the signal to start with. That's the entire reason for doing this.

With tools like MLS and noise, don't forget narrow band sweep. You will find it does produce fundamentals higher than was suggested.
 
did you pick up ringing around 4khz ?

Can you show the charts seperately ?

I could be mis-reading the chart, but it looks like you lost a lost of high end.

And wow, it really takes a while for the cone to settle down.

Norman

I personally cold not pick up the ringing at 4khz

And I was just as surprised as you are by the length of the cone ringing, seemed weird to me too, that's also why I'm waiting for someone to validate the measurements.
 
Well now for my 2 :2c:. I just put the Fostex FF 125wk in a floor standing speaker boxes I made back in march if this year. It is a rear ported trapezoid box. Now I Just soldered the wire on the ff125wk driver and the wire is also soldered on the binding post. This is a hi grade wire not your usual hook wire. Any who. I just got them in the speaker box at 11:40 p.m. today. I just plugged them in at 11:58 p.m. and ran them fullrange thu the t.v. With a yahama amp. I have to say they are getting sweeter as the day goes on. I just turned them off to give them a rest. Everything sound very natural to me no peakness or brightness like you say? I find these drivers very well made above thier price and value. Thanks to dave from planet 10 :D again for leading me to the right fullrange drivers. This is my second pair and my first pair in a box. The other pair I sold before I could test them. Now for me they sound just right I am very happy and I am going to keep playing them and enjoying them.;)


Now for part # 2 long post sorry.Just a note. I have had the FF85wk and they are a killer drivers no matter how you look at it. This is my fav. fullrange driver reguidless of price or cone materials out there. Again dave at planet 10 is right on with this little driver :D. Now I have had so many fullrange drivers and I will not take up the post to name and clam them all and what I think? But, As I was saying before I put the FF125wk in the box I had the fe126en drivers in with all the mods but, the dots. They are alot more livelier and not as natural as the ff series. They tend to be more on the peaky side on some things like female voices and sss and zzz. I have had the fe126en drivers senc. feb. and I have been playing around with them. I will say that the fe series doesn't like ported boxes but, the ff series does. Again I am very thankfull of dave from planet 10 for all his help on this forum and all he does with all the other people who work for him. I say that the FF series is a mind blower and I am a happy camper. Fostex is doing a great job.:nod: Mr. jeff
 
Well established they take considerable break in time.

One of the problems with break-in is if you are listening to them during that time, your brain will start to make adjustments. Even with no change, they will sound better. Our head plays some marvelous tricks on us. Better to you is just plain better and it does not matter what the numbers say.
 
I agree I hear no peakness at 7khz? I have had them playing on my yamaha amp and now they are palying on a audiolab 8000a that is the balck unit it was made I think in 1999? The ff125wk sound really to good to be true on this amp. Now for the first time I am really enjoying a fullrange speaker in years. I see no need for a tweeter right now and it sounds so natural next to the fe126en drivers and I am really not seeing a difference between 88 db and 93 db on my audiolabs amp maybe due to the mods on the fe126en drivers? I will have to go ahead and order me a new pair of the fostex fe126 en driver and leave them original and untouched and do a (A & B ) Testing side by side? Sorry not to get off the topic. Mr. Jeff
 
I have been playing with my new OB setup for a couple of months now, and after an initial honeymoon with sound of the FF125WK, I am now noticing a certain harshness to the sound (most probably in the 5-10khz region) and was wondering if anyone has witnessed addressed this issue.

I know that Dave (Planet10) said that some zig two-way glue on the back of the foam surround does help a bit, and I'll be doing this.

Another option is to fully Enabl these cones, but I don't know what kind of coating is needed and if/where microgloss would need to be applied.

I have previous experience with Enabl'ing my AN super12, so the technique would not be a problem.

Anyway, my setup is a double H-frame 15 inch subs with FF125WK on a flat panel, crossed actively using a 2x4 miniDSP...

Regards

Nick


A couple of questions? What type of box do you have them because if they are being broken in on the floor with the speakers pointing up I understand what your saying. I didn't enjoy their sound of my first pair due to not using them in boxes. Also what kind of stuffing do you have behind the drivers? I have found a mixture of two types of stuffing and the then another 2 mixtures of cloth on the side walls and behind the driver as well and wiring and better binding post not to much more then my first binding post I bought.. Also what kinda wood are you using? To bad your not in the united states I could tell you over the phone everything. I will try to post a picture on the this post.I am learning really fast every little change does make a differance no matter what anyone tells me my ears tells me differance. Mr. Jeff
 
Last edited:
Status
This old topic is closed. If you want to reopen this topic, contact a moderator using the "Report Post" button.