InclinedPlane said:
It's no surprise about the sensitivity rating of these drivers. Note that Martin has them listed in his original document, albeit he has been using the JX92 driver which has a similar sensitivity rating at 88.2 dB. Despite the Jordan having a power rating of 100 watts, I doubt this small driver will handle that for long.
Most magnetic materials will lose some of their power over time, but consider vintage alnico drivers which are 4+ decades in age... still they are sought after and many still perform exceptionally well.
As always, your personal preference for acceptable SPL levels is just that, your personal preference. Not everyone shares it, sorry. I've driven the F120A with 40-watt Push-Pull tube amps and they get plenty loud for me. For most of my listening I used a custom pair of 45 SET monoblocks and these drivers are exceptional at their price.
With regard to your bold statements regarding the F120A parts makeup and the F200A, are you speaking from direct experience with both drivers? I have listened to this driver extensively and there is no awful ringing. Others out here have also done some extensive listening to the F120A and nobody with direct experience has commented on such a problem.
Regards, KM
Any reason why cheaper drivers like these
http://www.partsexpress.com/pe/showdetl.cfm?&Partnumber=290-340
won't work well in an H frame OB design?
http://www.partsexpress.com/pe/showdetl.cfm?&Partnumber=290-340
won't work well in an H frame OB design?
Godzilla,
I looked at that Goldwood 15" driver and the 8 ohm version early in my scoping study, they both worked well in an OB but in an H frame. In the H frame there was a bit of a peak at the cut-off frequency and the impulse response had a significant ringing. I concluded they would work really well in an OB but probably not so well in an H frame. The Qts is a little too high for the H frame.
Hope that helps,
I looked at that Goldwood 15" driver and the 8 ohm version early in my scoping study, they both worked well in an OB but in an H frame. In the H frame there was a bit of a peak at the cut-off frequency and the impulse response had a significant ringing. I concluded they would work really well in an OB but probably not so well in an H frame. The Qts is a little too high for the H frame.
Hope that helps,
Indeed I am talking with direct experience kmaier. I listened to a pair of 200A (used and ?broken in?) and decided to resell them after only one hour. Also have a look at this site so you can be sure I'm not alone:
http://www.iol.ie/~waltonaudio/fostex.html
The supposedly wild accusations I make are indeed grounded in experience with expensive drivers that do not perform. Can I prove it? Nah. Everyone's opinions differ. But my experience with The Fostex FE166e and 206 was all good except a harsh top end. With the 200A it was all good except a ringing kind of metallic top end. (the 120 has the same cone, magnet, metal cap and suspension) With Lowther it was shouty mids, no bass with downright painfully harsh and exaggerated top end. With the AER MD2B it was a lack of enough top end and also harsh mids but low level detail to die for. With the ANS8 all good with less scrape n' grind in the upper mids when played louder.
http://www.iol.ie/~waltonaudio/fostex.html
The supposedly wild accusations I make are indeed grounded in experience with expensive drivers that do not perform. Can I prove it? Nah. Everyone's opinions differ. But my experience with The Fostex FE166e and 206 was all good except a harsh top end. With the 200A it was all good except a ringing kind of metallic top end. (the 120 has the same cone, magnet, metal cap and suspension) With Lowther it was shouty mids, no bass with downright painfully harsh and exaggerated top end. With the AER MD2B it was a lack of enough top end and also harsh mids but low level detail to die for. With the ANS8 all good with less scrape n' grind in the upper mids when played louder.
InclinedPlane,
Looks like you have been through quite a few drivers. Most of these drivers have a very good reputation. I have used a few of the drivers you have tried and later sold with great success.
Based on your frequent description of harshness, I have to wonder if it is the driver or the design in which you have tried to use the driver. To me it would appear that you have had a constant struggle with baffle step problems which leads to a harsh shouty high frequency response. I can make any of my full range drivers designs sound harsh and shouty, but then I can also tame them using appropriate filters and/or system design and the results are very pleasing.
The link you provided for the F200A shows a bass reflex enclosure and never mentions how the baffle step was accounted for in the design. It probably was not and the result was a harsh response, no big surprise. If you look at Bob Brines' TL design using the F200A, he does use a filter to rebalance the SPL response and his product has had glowing reviews. It takes a driver and a good system design to achieve outstanding performance. It is probably easier to make an inferior driver perform well with a good syatem design then to take a great driver and put it into an inappropriate design and hope for outstanding results.
I really wonder how much of what you are hearing is due to poor system design and not really a property of the driver. How are you designing your speaker systems? If you say that you are just building without doing any simulations or other detailed calculations, then I think you are generating some of your own problems.
Looks like you have been through quite a few drivers. Most of these drivers have a very good reputation. I have used a few of the drivers you have tried and later sold with great success.
Based on your frequent description of harshness, I have to wonder if it is the driver or the design in which you have tried to use the driver. To me it would appear that you have had a constant struggle with baffle step problems which leads to a harsh shouty high frequency response. I can make any of my full range drivers designs sound harsh and shouty, but then I can also tame them using appropriate filters and/or system design and the results are very pleasing.
The link you provided for the F200A shows a bass reflex enclosure and never mentions how the baffle step was accounted for in the design. It probably was not and the result was a harsh response, no big surprise. If you look at Bob Brines' TL design using the F200A, he does use a filter to rebalance the SPL response and his product has had glowing reviews. It takes a driver and a good system design to achieve outstanding performance. It is probably easier to make an inferior driver perform well with a good syatem design then to take a great driver and put it into an inappropriate design and hope for outstanding results.
I really wonder how much of what you are hearing is due to poor system design and not really a property of the driver. How are you designing your speaker systems? If you say that you are just building without doing any simulations or other detailed calculations, then I think you are generating some of your own problems.
Owning the FX-120 and having tested and measured 4 to get a pair, there can be some slight ringing at 15-16K (a few db and fairly high Q) but it is not in the range that should cause "harshness."
Not having heard the F200a, and without passing judgment, If it had harshness and IF that was connected to the dome, the same mechanism in the FX-120 or F120a would occur at roughly twice the frequency due to being roughly half the size and would have a completely different effect.
Sean
Not having heard the F200a, and without passing judgment, If it had harshness and IF that was connected to the dome, the same mechanism in the FX-120 or F120a would occur at roughly twice the frequency due to being roughly half the size and would have a completely different effect.
Sean
Thanks Martin, that does help.
Did you happen to look at this Goldwood too? I want to make a decision to buy one of these this week.
http://www.partsexpress.com/pe/showdetl.cfm?&Partnumber=290-346
It has a lower Qts. Would it be a better choice in an H frame?
If you haven't looked at this driver, that's ok. I think i will try an H frame regardless. It will fit my room and offer some flexibility with placement. I expect it will enhance bass response of my BIBs with nice warmth and fullness. I also plan to use a dedicated amp to drive the H frames. I'm pretty excited about starting another project too. First one since getting out of the hospital 6 months ago. Getting back in the saddle and doing things i normally do is great therapy. I hope to satisfy some curiosities and learn something in the process.
Peace,
Godzilla
Did you happen to look at this Goldwood too? I want to make a decision to buy one of these this week.
http://www.partsexpress.com/pe/showdetl.cfm?&Partnumber=290-346
It has a lower Qts. Would it be a better choice in an H frame?
If you haven't looked at this driver, that's ok. I think i will try an H frame regardless. It will fit my room and offer some flexibility with placement. I expect it will enhance bass response of my BIBs with nice warmth and fullness. I also plan to use a dedicated amp to drive the H frames. I'm pretty excited about starting another project too. First one since getting out of the hospital 6 months ago. Getting back in the saddle and doing things i normally do is great therapy. I hope to satisfy some curiosities and learn something in the process.
Peace,
Godzilla
Godzilla,
That is the one Goldwood driver I did not run simualtions for while I was looking at driver candidates. Don't know why I did not take a closer look, it looks excellent for an H frame. I bet you get bass down into the 20's with that driver if you just scale the cross-sectional area of my 18" H frame design down for the 15" driver. Leave the depth of the cabinet the same and the crossover point the same or lower. Should be a winner in both cost and performance.
That is the one Goldwood driver I did not run simualtions for while I was looking at driver candidates. Don't know why I did not take a closer look, it looks excellent for an H frame. I bet you get bass down into the 20's with that driver if you just scale the cross-sectional area of my 18" H frame design down for the 15" driver. Leave the depth of the cabinet the same and the crossover point the same or lower. Should be a winner in both cost and performance.
I never did bother to visit you in Clifton Park, MJ what a pity I was just over in Cohoes.
Anywho, I've tried to make the point that the paper cone fullrange drivers I've used (in various applications; recommended and not recommended) have all exhibited an irritating and often painful shrieking sound anywhere from 2-10khz depending on the driver. Even my crappy Chevy factory coaxial door speakers do it. Clock radio speakers do it. The F200A delivered none of this. Its problem was a sort of ringing produced by the 'dust cap'.
I'm pretty sure I've figured it out after all this time. It's simply a matter of diaphragm dampening. The F200A is paper and polymer (or all polymer I can't remember) and has a rubbery layer applied underneath. This solved the harshness issue for me although it did bring the moving mass up to almost 20g. The dust cover is an unrelated issue.
The AN has a sort of sticky material applied to the surround which has got to have some sort of positive effect since I don't hear much 'shrieking' or at least not nearly as much as the 206.
Everyone's rebuttal so far is to look at other issues, like amps and filters and enclosure types. But I've become convinced after experimentation that none of those things can adequately solve this one problem. Sure, they can ameliorate it somewhat indirectly. But whenever I can get the money together I'm gonna get an Enabled driver. If this one problem can be fixed I'll be happy as a clam.
And what's with putting filters inline with a fullrange driver? Isn't that defeating the whole idea? Aren't you moving back toward Wilson Audio at that point?
Mj, I don't 'design' anything. The drivers go on a 2' by 4' OB 1.5" thick and I don't care if they produce no bass; the 15"s do that. On the OB they reveal their flaws straight away. We already have people putting low Q drivers on OBs and claiming awesome results. We already have people using high DF low out/imp SS amps and claiming awesome results. I already discounted these things years ago after finding the same problems with paper drivers in a variety of configurations and systems.
So why do only a small amount of people make a similar complaint here on the forum?
1) they do. look at the giant interest in the enable technique.
2) they don't listen loud; where the problem is most evident
3) they attribute issues to the wrong amp, wrong box, wrong something.
4) they're older and have lost some of the sensitivity
5) they deny it; caught up in their own ideas which they try to sell to everyone else. Oh crap I'm doing it too
6) they accept it due to the other massive strengths of the designs and say things like 'you wouldn't drive a Bentley in a freshly-plowed field would you' or 'it's not a forgiving driver' or 'it's designed for only this' or 'it does best with this kind of music' or 'it's not gonna work in OB or with that amp' etc.
Everywhere throughout this forum and on the net I find brick-wall contradictions between audiophiles' recommendations for certain drivers. This more than anything tells me that I better just keep on keepin' on with what sounds good to me. And that's what we all do. I don't step in saying Lowther is crap just to get 300 people to hate me. My argument is that it's an excellent fullrange driver...if it sold for $50. Many of you just HATE the fact that I think the ANS8 eats Lowther for lunch on all counts except rise/decay. And I'm lovin' that.
Anywho, I've tried to make the point that the paper cone fullrange drivers I've used (in various applications; recommended and not recommended) have all exhibited an irritating and often painful shrieking sound anywhere from 2-10khz depending on the driver. Even my crappy Chevy factory coaxial door speakers do it. Clock radio speakers do it. The F200A delivered none of this. Its problem was a sort of ringing produced by the 'dust cap'.
I'm pretty sure I've figured it out after all this time. It's simply a matter of diaphragm dampening. The F200A is paper and polymer (or all polymer I can't remember) and has a rubbery layer applied underneath. This solved the harshness issue for me although it did bring the moving mass up to almost 20g. The dust cover is an unrelated issue.
The AN has a sort of sticky material applied to the surround which has got to have some sort of positive effect since I don't hear much 'shrieking' or at least not nearly as much as the 206.
Everyone's rebuttal so far is to look at other issues, like amps and filters and enclosure types. But I've become convinced after experimentation that none of those things can adequately solve this one problem. Sure, they can ameliorate it somewhat indirectly. But whenever I can get the money together I'm gonna get an Enabled driver. If this one problem can be fixed I'll be happy as a clam.
And what's with putting filters inline with a fullrange driver? Isn't that defeating the whole idea? Aren't you moving back toward Wilson Audio at that point?
Mj, I don't 'design' anything. The drivers go on a 2' by 4' OB 1.5" thick and I don't care if they produce no bass; the 15"s do that. On the OB they reveal their flaws straight away. We already have people putting low Q drivers on OBs and claiming awesome results. We already have people using high DF low out/imp SS amps and claiming awesome results. I already discounted these things years ago after finding the same problems with paper drivers in a variety of configurations and systems.
So why do only a small amount of people make a similar complaint here on the forum?
1) they do. look at the giant interest in the enable technique.
2) they don't listen loud; where the problem is most evident
3) they attribute issues to the wrong amp, wrong box, wrong something.
4) they're older and have lost some of the sensitivity
5) they deny it; caught up in their own ideas which they try to sell to everyone else. Oh crap I'm doing it too
6) they accept it due to the other massive strengths of the designs and say things like 'you wouldn't drive a Bentley in a freshly-plowed field would you' or 'it's not a forgiving driver' or 'it's designed for only this' or 'it does best with this kind of music' or 'it's not gonna work in OB or with that amp' etc.
Everywhere throughout this forum and on the net I find brick-wall contradictions between audiophiles' recommendations for certain drivers. This more than anything tells me that I better just keep on keepin' on with what sounds good to me. And that's what we all do. I don't step in saying Lowther is crap just to get 300 people to hate me. My argument is that it's an excellent fullrange driver...if it sold for $50. Many of you just HATE the fact that I think the ANS8 eats Lowther for lunch on all counts except rise/decay. And I'm lovin' that.
Thanks Martin! I may just buy a pair of those and give it a go. I re read your paper (Jordan OB) tonight and did not find the reasoning for the depth of the H frame. I was going to cheat a little to make things easier for me. I was planning to make it less deep. My listening room is small. I want to fit them into the room with the BIBs. That's why i want to go with 15 inch drivers rather than the 18 inch. LOL!
I can always easily extend the H frame if the performance is not there with the slimmer ones.
Godzilla
I can always easily extend the H frame if the performance is not there with the slimmer ones.
Godzilla
Any idea how the Seas CA26RE4X woofer would compare to the Goldwood GW1858 for this application in an H-Frame?
The specs of both are side by side below:
Thank you!
-David
The specs of both are side by side below:
An externally hosted image should be here but it was not working when we last tested it.
Thank you!
-David
InclinedPlane said:
Hi IP,
Well, I've not heard the F200A... so I can't comment on it. It would appear you've not heard the F120A so to draw a conclusion of perceived flaws from one to the other really isn't grounded by any facts. Also, it doesn't make sense to assume the components between them are the same... Fostex do tend to optimize many of their better components and the F120A is, IMHO, probably their best 4.5" FR driver despite it's lower sensitivity and limited power handling.
As for some other Fostex drivers, I have found the FE126E to have an irritating upper mid-range "shout" when driven much beyond 1-watt or so. Yet, it's probably the "fair haired child" from the Fostex lineup based on how many people use it and in a wide array of designs.
I would suspect that you may have some other equipment related anomalies that tend to add up in your system as you seem to have experienced much of the same problem with all of the drivers you mentioned. I have no idea what your system is comprised of so I can't comment any further. The only solid-state equipment in my system is a CD/DVD front-end driving an external mastering DAC. Everything else is vacuum tube based. You may get better results if you look at other parts of your system and look for problems there.... just a thought.
Regards, KM
ttan98 said:
Hi TT,
The enclosure I used was based on the Fostex plans for the F120A and FX120. It's a simple 10-liter ported enclosure built from 3/4" plywood with blackhole products inside. I don't consider it optimal but it becomes a good baseline (no pun intended) for how these two drivers (FX120 and F120A) perform. I did use a 1/4" cork sheet on the front baffle which allows a flush mounting of the driver. Overall not an expensive build sans the drivers. Here's a picture with the FX120 installed:
An externally hosted image should be here but it was not working when we last tested it.
Regards, KM
kmaier said:
Thks, this setup does not give you enough bass what do you use to supply you enough bass extension.
Does this unit give you suffcient high freq response?
Like most full range the directivity is not adequate, ie once you move out of central positiom you loose the imaging. This would be true of this model, F120A as well?
ttan98 said:
Hi TT,
True, this small enclosure does not cover the last octave or two, depending on how low you consider to be adequate, i.e., a 16Hz organ pedal note. I've been using them on a pair of Studio Tech Ultra 24" stands. In my living room they are quite good down to 50Hz and maybe a bit lower, then they drop off pretty quick (confirmed with a signal generator driving them while setup in the actual listening space).
Imaging is really very good, but as it is a single driver, high frequency dispersion does suffer as you move off-axis and the Fostex datasheet shows response for 30- and 60-degrees. Nothing really new here.
As for high frequency extension, I bought a pair of T90A tweeters intended to pair up with these. However, once I had these playing, I found no real lack of response for the last octave or so, hence I've not used them yet. Of course, others may feel differently and prefer to bring in a super tweeter for the last octave. With some really good analogue recordings, the sizzle on cymbals is crisp and even brushes on a snare drum sound quite natural.
Hope this helps.
Regards, KM
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