(If there was another thread on this, then sorry. I couldn't find it with the search.)
Just got back from listening to Martin’s OB’s with the Jordan JX92 and the 18” Goldwood woofer. Brief analysis:
Let me begin with the bass: WOW!!
full, rich bass; lots of detail & nuance. I have been using sealed and ported subs for decades, but this is the bass I want! We didn’t get around to trying the 1812 Overture, but on Temple Caves (from Mickey Hart’s Planet Drum CD) the bottom end was all there. How much deeper do they go? Don’t know, but I’m sure they get down into the 20’s. And at about $60 per driver, they aren’t just great sounding, they’re a STEAL! For those evaluating bass systems: you owe it to yourself to check this out--don’t be discouraged by the naysayers; like Obi-Wan said: Trust your ears Luke. Trust your ears!. 
I have to look into how the Eminence Alpha 15” driver from Martin’s earlier project would do in an H frame. I suspect that it would go deep enough to satisfy me, and in a bit smaller package. 
As for the Jordan: it does nothing wrong. Its sound is smooth, with flat response and good HF extension, but it didn’t grab me. I think it doesn’t have the detail and ‘bite’ (for lack of a better word) that I would like to hear. It’s very listenable, but it didn’t excite me. When Martin switched over to the Lowthers in his MLTL, everything suddenly blossomed--sound stage expanded, detail and nuance increased, and I was engaged by the music. I know that it’s not fair to compare the Jordans to the Lowthers, as they aren’t in the same price league, but hey, there it is. Perhaps if I spent more time w/ the Jordans, I would come to appreciate them, but for now: sorry, they just get a shrug.
And don't think I'm down on OBs. I listened to Martin's original OBs with Lowthers and dual Alpha 15's--those are simply amazing!
Cheers, Jim
Just got back from listening to Martin’s OB’s with the Jordan JX92 and the 18” Goldwood woofer. Brief analysis:
Let me begin with the bass: WOW!!
full, rich bass; lots of detail & nuance. I have been using sealed and ported subs for decades, but this is the bass I want! We didn’t get around to trying the 1812 Overture, but on Temple Caves (from Mickey Hart’s Planet Drum CD) the bottom end was all there. How much deeper do they go? Don’t know, but I’m sure they get down into the 20’s. And at about $60 per driver, they aren’t just great sounding, they’re a STEAL! For those evaluating bass systems: you owe it to yourself to check this out--don’t be discouraged by the naysayers; like Obi-Wan said: Trust your ears Luke. Trust your ears!. I have to look into how the Eminence Alpha 15” driver from Martin’s earlier project would do in an H frame. I suspect that it would go deep enough to satisfy me, and in a bit smaller package. As for the Jordan: it does nothing wrong. Its sound is smooth, with flat response and good HF extension, but it didn’t grab me. I think it doesn’t have the detail and ‘bite’ (for lack of a better word) that I would like to hear. It’s very listenable, but it didn’t excite me. When Martin switched over to the Lowthers in his MLTL, everything suddenly blossomed--sound stage expanded, detail and nuance increased, and I was engaged by the music. I know that it’s not fair to compare the Jordans to the Lowthers, as they aren’t in the same price league, but hey, there it is. Perhaps if I spent more time w/ the Jordans, I would come to appreciate them, but for now: sorry, they just get a shrug.
And don't think I'm down on OBs. I listened to Martin's original OBs with Lowthers and dual Alpha 15's--those are simply amazing!
Cheers, Jim
Mike,
I think I'd say:
1. Lowthers in the OB
2. Lowthers in MLTL
10. Jordans in OB
The Lowthers in the OB are perhaps the best speakers I have ever heard. (Without having speakers in a side-by-side test, it's a bit hard to be absolutely certain.) Too big & too expensive for me to build them, but they are truly spectacular.
Cheers, Jim
I think I'd say:
1. Lowthers in the OB
2. Lowthers in MLTL
10. Jordans in OB
The Lowthers in the OB are perhaps the best speakers I have ever heard. (Without having speakers in a side-by-side test, it's a bit hard to be absolutely certain.) Too big & too expensive for me to build them, but they are truly spectacular.
Cheers, Jim
The Alphas and the Goldwoods give nice extension, good midbass and plenty of output but the motors are too weak to do the job right, I found. When I switched to the Pyle PPA15 I found that the bass was much quicker and tighter. But with the lower Q they didn't have as much output in OB. I'm interested in the SI Augie but put off by the advertised 'mass disc'. The moving mass needs to be as low as possible for accurate sound and to make the cone heavier just to raise the q with an already smallish magnet makes me cringe.
Too big I could live with, but the expensive part I am with you. $2000 plus for the Lowthers puts me off as well. I built Virtual MLTL with the Fostex 206e and that was very good. I then put the 206e in the Half Chang by Scott Moose and was very pleased with them. I think you did as well?
Back in July I built Martin's OB with the Fostex 103e and have been with them since. More base from the 15" Alpha's did the trick for me. Very very good to listen to my jazz collection and female artist.
I did see a thread on using the 206e with the 15" Alpha's but have not seen any additional post there lately.
Thanks for the ranking
Mike
Back in July I built Martin's OB with the Fostex 103e and have been with them since. More base from the 15" Alpha's did the trick for me. Very very good to listen to my jazz collection and female artist.
I did see a thread on using the 206e with the 15" Alpha's but have not seen any additional post there lately.
Thanks for the ranking
Mike
A sealed powered sub has never integrated properly with my BIBs. Bass sounds boxy. I am thinking now about building two OB subs using the Eminence or Goldwood. I was wondering if using a separate amp to power the OBs would provide any advantages such as volume matching, crossover control, etc.
I may open a new thread to discuss using OB as bass extension for BIBs.
TIA,
Godzilla
I may open a new thread to discuss using OB as bass extension for BIBs.
TIA,
Godzilla
InclinedPlane,
The goldwood was in no way deficient. Bass is clean, detailed, nuanced. I see nothing to be gained by spending more on a low Q driver. The active cross-over and separate amp allow it to be dialed in perfectly. And if you move them around or your taste changes, they can be easily re-adjusted. If you want to use a low Q driver, why not put it in a suitable box where it will work better?
Mike,
Yes, I did make a pair of HC's w/ FE206E's. And every time I visit our daughter & son-in-law, I listen to them w/ great pleasure.
They sound very good to me whether they are playing at a whisper or a roar, something that eludes most commercial speakers. (At least in my experience.)
Cheers, Jim
The goldwood was in no way deficient. Bass is clean, detailed, nuanced. I see nothing to be gained by spending more on a low Q driver. The active cross-over and separate amp allow it to be dialed in perfectly. And if you move them around or your taste changes, they can be easily re-adjusted. If you want to use a low Q driver, why not put it in a suitable box where it will work better?
Mike,
Yes, I did make a pair of HC's w/ FE206E's. And every time I visit our daughter & son-in-law, I listen to them w/ great pleasure.
They sound very good to me whether they are playing at a whisper or a roar, something that eludes most commercial speakers. (At least in my experience.)Cheers, Jim
My approach to bass drivers for OB/dipole design is based on the following logic.
1) At 200 to 400 Hz there will be a hump in the SPL response due either to the OB geometry or due to the first resonance of a U or H frame.
2) I set the acoustic crossover to a full range or midrange driver to take advantage of this response and to mitigate the hump. So I cross over the bass driver using a 2nd order low pass filter set between 100 and 200 Hz. Then for the full range or midrange driver, I set the high pass filter between 200 and 400 Hz depending on the crossover slope.
3) I don't use EQ so I always look for a high Qts (~ 1.0) driver with an efficiency that is at least 6 dB greater than the full range or mid range driver. If the efficiency does not look adequate, I will use the boost feature in my active crossover. But this means a passive crossover option is not in the cards at a later date.
4) This combination, if done correctly, will yield a reasonably flat SPL response that will go deep enough to surprise a lot of people who think of dipole systems as being light in the low frequencies.
What this really means is that the bass driver is only driven from fs to approximately 200 Hz. This is well below any cone break-up modes or frame ringing problems. Any decent large diameter pro driver with a high Qts will behave as a piston over this frequency range. There will be no flapping cone or booming resonant bass. The driver will be under complete control of the amp.
So I look for a high Qts driver (~ 1.0) and a decent fs. If you are going to use an OB, then an fs of 40 Hz is adequate since in a reasonly sized OB you are not going to get below 40 Hz without EQ. For an H or U frame driver, look for a lower fs. Achieving 20 Hz in an H frame is easily possible. Based on these requirements, I have found that 15" or 18" bass drivers priced between $50 and $70 will be perfectly adequate for a music system. I don't know anything about home theater but I suspect the same low cost drivers will also be acceptable. I don't see any reason at this time to spend more on the bass driver.
The more expensive IB or OB 15" drivers will have a much larger Xmax compared to the cheaper versions. But my experience is that with music, even played at loud volume levels, the cone's barely move. I did subject my Goldwood H frame to the 1812 overture this past week. I played it through twice, once to listen and once to watch the cone motion. My 16 year old son was laughing telling my how cool it was when the floor shook. Watching the cone, at a fairly high volume level produced by a 200 W SS amp, I estimate they moved about 1/2" peak to peak. No damage and no bottoming of the voice coil. Would a more expensive driver have done a better job, maybe but this is not something I do on a daily basis so I am not really interested. For music, I have not experienced any problems where the cone motion approachs the stated Xmax of the cheaper drivers.
I would rank my systems that Jim and I have listened to in this order of increasing in performance.
1) Jordan JX92S and Goldwood H frame - the Jordan driver is as Jim discribed. He was not too fond of it but I can see where others might like it more then he did. It is smooth and kind of layed back. All the frequencies are reproduced but not with the lifelike performance of the Lowther DX3. I am still going to try a few other similar sized full range Fostex drivers to see if I can close the gap to the Lowthers, that would be really nice price wise and maybe even allow a passive approach to the crossover.
2) Lowther DX3 ML TL - compared to the Jordan with the H frame this system is bass light. Better detail and dynamics but probably not acceptable to a bass fiend. Good for acoustic music.
3) Lowther PM2A with 2 Eminence Alpha 15A drivers on a huge OB - a big improvement over 1) and 2). No comparison as far as big sound and dynamics goes. The bass does not go nearly as deep as the H frame.
4) Lowther and Goldwood H frame - This is probably my next step and was mocked up when Jim and I combined the Lowther DX3 ML TL with the Goldwood H frame using my active crossover. This has the potential of much deeper and better bass then the Alpha 15A OB system while still using a Lowther for everything above 200 Hz. I can see this combination being another big step up in performance. This will require 8 to 10 dB of boost to be applied to the Goldwood to match the efficiency of the Lowther, maybe it would later benefit from a pair of Goldwood H frames per side. Think about $2k of Lowther drivers mated to $120 of Goldwood bass drivers, seems wrong but no question in my mind that it will be a killer set-up.
Jim and I had a lot of fun yesterday afternoon. Jim has put together a test disc with all kinds of music styles and effects which really tested my system. Some of the selections are well known and some I have no idea where he dug them up, but it is an interesting listening experience.
Hope that rather long dialog is of some use,
1) At 200 to 400 Hz there will be a hump in the SPL response due either to the OB geometry or due to the first resonance of a U or H frame.
2) I set the acoustic crossover to a full range or midrange driver to take advantage of this response and to mitigate the hump. So I cross over the bass driver using a 2nd order low pass filter set between 100 and 200 Hz. Then for the full range or midrange driver, I set the high pass filter between 200 and 400 Hz depending on the crossover slope.
3) I don't use EQ so I always look for a high Qts (~ 1.0) driver with an efficiency that is at least 6 dB greater than the full range or mid range driver. If the efficiency does not look adequate, I will use the boost feature in my active crossover. But this means a passive crossover option is not in the cards at a later date.
4) This combination, if done correctly, will yield a reasonably flat SPL response that will go deep enough to surprise a lot of people who think of dipole systems as being light in the low frequencies.
What this really means is that the bass driver is only driven from fs to approximately 200 Hz. This is well below any cone break-up modes or frame ringing problems. Any decent large diameter pro driver with a high Qts will behave as a piston over this frequency range. There will be no flapping cone or booming resonant bass. The driver will be under complete control of the amp.
So I look for a high Qts driver (~ 1.0) and a decent fs. If you are going to use an OB, then an fs of 40 Hz is adequate since in a reasonly sized OB you are not going to get below 40 Hz without EQ. For an H or U frame driver, look for a lower fs. Achieving 20 Hz in an H frame is easily possible. Based on these requirements, I have found that 15" or 18" bass drivers priced between $50 and $70 will be perfectly adequate for a music system. I don't know anything about home theater but I suspect the same low cost drivers will also be acceptable. I don't see any reason at this time to spend more on the bass driver.
The more expensive IB or OB 15" drivers will have a much larger Xmax compared to the cheaper versions. But my experience is that with music, even played at loud volume levels, the cone's barely move. I did subject my Goldwood H frame to the 1812 overture this past week. I played it through twice, once to listen and once to watch the cone motion. My 16 year old son was laughing telling my how cool it was when the floor shook. Watching the cone, at a fairly high volume level produced by a 200 W SS amp, I estimate they moved about 1/2" peak to peak. No damage and no bottoming of the voice coil. Would a more expensive driver have done a better job, maybe but this is not something I do on a daily basis so I am not really interested. For music, I have not experienced any problems where the cone motion approachs the stated Xmax of the cheaper drivers.
I would rank my systems that Jim and I have listened to in this order of increasing in performance.
1) Jordan JX92S and Goldwood H frame - the Jordan driver is as Jim discribed. He was not too fond of it but I can see where others might like it more then he did. It is smooth and kind of layed back. All the frequencies are reproduced but not with the lifelike performance of the Lowther DX3. I am still going to try a few other similar sized full range Fostex drivers to see if I can close the gap to the Lowthers, that would be really nice price wise and maybe even allow a passive approach to the crossover.
2) Lowther DX3 ML TL - compared to the Jordan with the H frame this system is bass light. Better detail and dynamics but probably not acceptable to a bass fiend. Good for acoustic music.
3) Lowther PM2A with 2 Eminence Alpha 15A drivers on a huge OB - a big improvement over 1) and 2). No comparison as far as big sound and dynamics goes. The bass does not go nearly as deep as the H frame.
4) Lowther and Goldwood H frame - This is probably my next step and was mocked up when Jim and I combined the Lowther DX3 ML TL with the Goldwood H frame using my active crossover. This has the potential of much deeper and better bass then the Alpha 15A OB system while still using a Lowther for everything above 200 Hz. I can see this combination being another big step up in performance. This will require 8 to 10 dB of boost to be applied to the Goldwood to match the efficiency of the Lowther, maybe it would later benefit from a pair of Goldwood H frames per side. Think about $2k of Lowther drivers mated to $120 of Goldwood bass drivers, seems wrong but no question in my mind that it will be a killer set-up.
Jim and I had a lot of fun yesterday afternoon. Jim has put together a test disc with all kinds of music styles and effects which really tested my system. Some of the selections are well known and some I have no idea where he dug them up, but it is an interesting listening experience.
Hope that rather long dialog is of some use,
>>> Think about $2k of Lowther drivers mated to $120 of Goldwood bass drivers, seems wrong...
It does! But who's complaining? Martin, do you think the Goldwood in the H frames as you designed would work well with BIB's? My feeling is to leave the BIBs playing full out and changing the crossover on the H frames. I was thinking about lowering it to 50hz to 100hz and fiddle with the volume control of a dedicated amp to make it work. Your H frame design will sit nicely in front of my BIBs without obstructing them. The H frames could be moved forward or backwards and side to side for best results. I am excited about your H frame ideas! Thanks!
Godzilla
It does! But who's complaining? Martin, do you think the Goldwood in the H frames as you designed would work well with BIB's? My feeling is to leave the BIBs playing full out and changing the crossover on the H frames. I was thinking about lowering it to 50hz to 100hz and fiddle with the volume control of a dedicated amp to make it work. Your H frame design will sit nicely in front of my BIBs without obstructing them. The H frames could be moved forward or backwards and side to side for best results. I am excited about your H frame ideas! Thanks!
Godzilla
Martin: Thank you for post no. 9.
I think that many here have been waiting for this kind of summary.
It would be great if we could find a Fostex driver that came closer to the Lowthers performance (obvious cost reasons). My FX120eNs are in transit from Dave, would these be good contenders? A Passive XO solution would be very welcome also.
I do not have space for an OB project at the moment, but maybe soon...
I think that many here have been waiting for this kind of summary.
It would be great if we could find a Fostex driver that came closer to the Lowthers performance (obvious cost reasons). My FX120eNs are in transit from Dave, would these be good contenders? A Passive XO solution would be very welcome also.
I do not have space for an OB project at the moment, but maybe soon...
Godzilla said:
I think that both the Goldwood and the Eminence Alpha 15A would provide the bass for your BIB speakers. The trade-off will be size versus bass extension, looks like the price of each is about the same. I have never heard a BIB design so I can't provide much of an opinion but I would recommend putting a crossover on both the BIB and the H frame to make get them to work better together, I am not a big fan of running one driver full range and then using the crossover only on the sub.
dublin78 said:
I am looking hard at the FX120 and the F120A as alternatives to the Jordan, it will be an interesting comparison and I have no idea which of the three will work the best. Unfortunately the FX120 is out of stock at Madisound so I am waiting for them to receive more drivers. Hopefully in the next few months I will make some progress.
Maybe the fostex F200A with 2 X Pyle or Alpha 15s or a single Goldwood would be worth a look. I have not heard this speaker but it has a higher power rating and higher xmax than the other smaller Fostex drivers. It is a bit expensive but nowhere near the cost of Lowthers. Maybe with a rear facing tweeter for "air" or to make up for any falling off of the highs on the 8" unit. Any comment on this combination?
jamikl
jamikl
jamikl said:
Once you relieve the full range driver of the bass frequencies the Xmax is not so much of an issue. The F200A is not an inexpensive driver and I am not sure what you would gain over either the F120A or even the FX120. My thinking is to look for a full range driver that does the high frequencies well and not worry about the frequencies below 200 Hz, this would lead me towards looking at smaller drivers that are much less expensive. But that is only my approach based on my "vision", others might follow a different path based on a different set of trade-offs.
Martin,
I have had both the FX120 and F120A for quite some time and have listened to both extensively. These drivers share much in common from a materials point... i.e., the die-cast frame, spider, cone, dust cover and surround. The cone looks different from the front but looks the same from the rear. The surround also looks slightly different but it's unclear if the difference is purely for aesthetics... the cone color seems to be about it. The major difference lies in the magnet structure, ceramic versus Alnico and the fact that the F120A is from their Laboratory Series and still made in Japan while the FX120 is made in China.
From a comparison for listening, the F120A is the winner and by a good margin. They provide much better detail and low-level information that just gets lost with the FX120. High-frequency content, like the sizzle on cymbals, are excellent on the F120A while the FX120 simply doesn't deliver here. I also found the F120A has better tolerance, as my FX120 pair is off by ~1 dB in output level and the F120A pair is spot on. IMHO, they are worth the 2x price based on the performance improvement alone. I actually bought an extra pair of these after swapping from the FX120.
I also am interested in pairing up the F120A with a pair of H-frame subs at some point. I'm leaning towards a 15-inch, but still have a mental block on such a cheap driver paired up with the F120A. I'd actually like to mate it with another Fostex driver but that seems unlikely. Hope this POV is helpful.
Regards, KM
I have had both the FX120 and F120A for quite some time and have listened to both extensively. These drivers share much in common from a materials point... i.e., the die-cast frame, spider, cone, dust cover and surround. The cone looks different from the front but looks the same from the rear. The surround also looks slightly different but it's unclear if the difference is purely for aesthetics... the cone color seems to be about it. The major difference lies in the magnet structure, ceramic versus Alnico and the fact that the F120A is from their Laboratory Series and still made in Japan while the FX120 is made in China.
From a comparison for listening, the F120A is the winner and by a good margin. They provide much better detail and low-level information that just gets lost with the FX120. High-frequency content, like the sizzle on cymbals, are excellent on the F120A while the FX120 simply doesn't deliver here. I also found the F120A has better tolerance, as my FX120 pair is off by ~1 dB in output level and the F120A pair is spot on. IMHO, they are worth the 2x price based on the performance improvement alone. I actually bought an extra pair of these after swapping from the FX120.
I also am interested in pairing up the F120A with a pair of H-frame subs at some point. I'm leaning towards a 15-inch, but still have a mental block on such a cheap driver paired up with the F120A. I'd actually like to mate it with another Fostex driver but that seems unlikely. Hope this POV is helpful.
Regards, KM
MJK said:
See how we're rediscovering that the 'short throw' approach of vintage drivers was better then and is better now. 'Conventional' drivers and systems boast high xmax and often high mms drivers that move alot of air but create more distortion and seem to do a poor job of reproducing basslines accurately. So maybe the tradeoff is larger surface area for big drivers and consequently big speaker systems. That's perfectly fine to me.
Dublin,
Yes, I've been somewhat vocal about the comparison for well over a year now and had some other posts here and audiocircle to the same. Others have also noted the same results from comparison tests. Granted, the F120A is more than twice the price of the FX120, but having direct experience with both, I would not choose the FX120 unless financial constraints forced me otherwise.
Jim Rebman has a pair of F120A that were enabled by Bud and were used for the Fonkensteen design and final tuning... unfortunately I'm not sure anyone has done adequate listening in a proper enclosure to accurately describe the difference (stock vs enabled)... (Bud, Chris, et al please jump in here if I'm in error). I've not heard the enabled pair so I can't comment on the difference.
Regards, KM
Yes, I've been somewhat vocal about the comparison for well over a year now and had some other posts here and audiocircle to the same. Others have also noted the same results from comparison tests. Granted, the F120A is more than twice the price of the FX120, but having direct experience with both, I would not choose the FX120 unless financial constraints forced me otherwise.
Jim Rebman has a pair of F120A that were enabled by Bud and were used for the Fonkensteen design and final tuning... unfortunately I'm not sure anyone has done adequate listening in a proper enclosure to accurately describe the difference (stock vs enabled)... (Bud, Chris, et al please jump in here if I'm in error). I've not heard the enabled pair so I can't comment on the difference.
Regards, KM
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