Re: New Curved BLH
I am honoured to hear this box last weekend. The upper bass and above response = impressive ! bass is tight & fast, better than a Bass reflex. However, I think the low bass has being roll off too early... but general sound tracks are alright especially if they dont have much material below 50hz.
I must also highlight that the 6LU8 with special output trannies & power supply amp contributes to this phenomena sound that I had heard. Well done to BTW and gang !
Just sharing the happenings in Pass threads:
Seems like Feastrex is really winning alot of
http://www.diyaudio.com/forums/showthread.php?s=&threadid=148620
BTW said:One of our horn builders over here came out with this BLH.. This is just a testing prototype and it sounds excellent with the D5nf
I am honoured to hear this box last weekend. The upper bass and above response = impressive ! bass is tight & fast, better than a Bass reflex. However, I think the low bass has being roll off too early... but general sound tracks are alright especially if they dont have much material below 50hz.
I must also highlight that the 6LU8 with special output trannies & power supply amp contributes to this phenomena sound that I had heard. Well done to BTW and gang !
Just sharing the happenings in Pass threads:
Seems like Feastrex is really winning alot of
http://www.diyaudio.com/forums/showthread.php?s=&threadid=148620
Congrats, Chris.
Terry Cain's old digital system was based on a LynxTwo soundcard, I thought it sounded great. Hard to tell the difference between it and my Echo Mona or a good vinyl setup. Frankly, hard to tell the difference between an Echo Mona and anything else built today.
Ive heard some great digital but better speakers. Dumping the most extreme cash into a digital setup instead of everything else smacks of chasing the dragon. My rule is to own a cd collection that values at least 5 times that of my cd playback system.
I too am a fan of the triple port enclosure especially for small spaces and I laud the efforts of BTW and his friends in building a presumably viable BLH for the D5nf. I hope to hear a pair some day.
-Clark
The Granada is Coming!
An externally hosted image should be here but it was not working when we last tested it.
Here is is sans moon:
It will play all kinds of music.
We do hope some will be over the moon.
An externally hosted image should be here but it was not working when we last tested it.
It will play all kinds of music.
We do hope some will be over the moon.
First Show Report - Jonathan Valin
Here is the first show report on the Granada from Jonathan Valin of the Absolute Sound:
"Another Fifth Floor winner was the Lotus Group’s $69k-$160k two-way dipole Granada with ultra-sexy Feastrex field-coil drivers In fact, this speaker was so good it earned one of my little asterisks as a “Best of Show” contender (and I only gave out a handful of these). Outside of the Vandy Model 7, the Granada reproduced my Guitar Gabriel (“Keys to the Highway”) and Captain Like (“Rainy Night in You Know Where”) cuts with more sheer you-are-there realism than anything else at the show. I know nothing about Lotus Group but, like the Nordic Tone and the Haniwa, this is a speaker that may truly be great. (BTW, the Granada’s design is uncannily similar to that of the Da Vinci Virtù, which so wowed me at the last CES and which I also think may be a world-class transducer.) I don’t know if it was the Granada or my ecstatic response to it, but soon after I left the room the lights in the hotel went out.
http://www.avguide.com/blog/rmaf-report-speakers-over-20k
"
Here is the first show report on the Granada from Jonathan Valin of the Absolute Sound:
"Another Fifth Floor winner was the Lotus Group’s $69k-$160k two-way dipole Granada with ultra-sexy Feastrex field-coil drivers In fact, this speaker was so good it earned one of my little asterisks as a “Best of Show” contender (and I only gave out a handful of these). Outside of the Vandy Model 7, the Granada reproduced my Guitar Gabriel (“Keys to the Highway”) and Captain Like (“Rainy Night in You Know Where”) cuts with more sheer you-are-there realism than anything else at the show. I know nothing about Lotus Group but, like the Nordic Tone and the Haniwa, this is a speaker that may truly be great. (BTW, the Granada’s design is uncannily similar to that of the Da Vinci Virtù, which so wowed me at the last CES and which I also think may be a world-class transducer.) I don’t know if it was the Granada or my ecstatic response to it, but soon after I left the room the lights in the hotel went out.
http://www.avguide.com/blog/rmaf-report-speakers-over-20k
"
I thought they sounded better than any other speakers I heard at the show. I even compared them directly with the $180,000 Focal Grande Utopia speakers--I asked them to play an 11-minute song I know very well on an LP, and then a few minutes later I listened to the same thing on the Granada speakers, and the Granada speakers were clearer, cleaner, more open and more fun than the Focals. My wife felt the same way.
Joe, you've really come up with a great speaker here. Congratulations!
Mike
Joe, you've really come up with a great speaker here. Congratulations!
Mike
Joe - Congratulations on your design and it's reception at the show!!!
I'm not at all surprised by the results, I came to the same layout conclusions with my D9's; the DEQX xover / processor is inbound, at present somewhere in a DHL warehouse. For my own OB I've taken a shine to Berts Diamond speaker albeit with a rear firing tweeter but I'll be looking for a little acoustic bass support from a U frame for the dual bass units.
Meanwhile a pair of Quad 2905's are also on their way to help with the voicing and to give me something to listen to whilst the glue is drying...
Hmmm just need save up for a pair of 9" field coils.... and more Valhalla cabling gulp....
I'm not at all surprised by the results, I came to the same layout conclusions with my D9's; the DEQX xover / processor is inbound, at present somewhere in a DHL warehouse. For my own OB I've taken a shine to Berts Diamond speaker albeit with a rear firing tweeter but I'll be looking for a little acoustic bass support from a U frame for the dual bass units.
Meanwhile a pair of Quad 2905's are also on their way to help with the voicing and to give me something to listen to whilst the glue is drying...
Hmmm just need save up for a pair of 9" field coils.... and more Valhalla cabling gulp....
We ended up doing almost everything contrary to accepted standards as posed by the single ended, single driver analog only camp - not by design, but partly by circumstance and largely by necessity. Let's recount the ways we departed from accepted standard:
1.) We added woofers and a rear firing tweeter to a driver created for use by itself in a dedicated enclosure.
2.) We used a digital crossover
3.) We used solid state amplification for top and bottom.
4.) We ran an analog turntable's phono signal created with an expensive arm and cartridge through a digital crossover.
So like Klipsch in the 60s, perhaps we should have named our speaker "The Heresy". But here's the rub: every approach has its compromises and drawbacks. Let's address these one by one:
1.) Woofers and rear tweeter vs. single driver only:
In an open baffle, the single driver approach is a non starter - no bass to speak of. We decided that an open baffle has certain advantages. The main one being - no box means no box colorations. Another is that since an open baffle radiates in a figure eight pattern, there is a null in the output at the sides of the speaker. This means less excitement of bass nodes in the room.
We measured the speaker 36 times in the vertical plane and 36 times in the horizontal plane for axial response, listening window response and overall power response. In order to balance the rear high frequency response with the Feastrex driver a rear tweeter was a necessity. The opening at the rear of the Feastrex's frame is small and there's no rear facing whizzer cone. Since the tweeter is facing rearward it has no effect on the character of the main driver facing forward.
2.) Digital vs. analog crossover. At first glance it would seem that an analog crossover would be superior to a digital crossover as the analog signal is not chopped up and rearranged by the conversion process. In fact I resisted using the digital crossover myself until I heard and understood what it brings to the table.
Here's what you can't do with an analog crossover: You can't perfectly match drivers. (BTW, the engineer was amazed at how closely the two D5e II drivers were - not as close as machine made cones, but way closer than he expected - a testament to the precision and accuracy of Mr. Teramoto's handiwork). You can't perfectly time align the drivers. You can't use 4th order crossovers (not in a practical sense at least). You can't contour precise frequency bands, and you can't adjust for actual room response.
Here's what you get with a digital crossover: Absolute rock solid imaging with instruments in real and proper position and proportion to one another (Outside of the Feastrex D5e II themselves, this is largely what gives rise to Jonathan Valin's statement that the Granada had "more sheer you-are-there realism than anything else at the show". There were of course other factors involved as well, but I attribute a large portion of that to the Xover.), the ability to contour the Xover to the best advantage of the drivers, and the ability to go into any room anywhere and know that you can make the speaker perform to its maximum capabilities. All information is processed in real time at 48 bits - more than enough to have virtually transparent throughput.
3.) Solid state amplification used top and bottom. We were hoping to get the Maekawa amplifiers in time for the show, but they only arrived after the show began and we did not have time to adjust the speaker for them. Greatness is worth waiting for, and we will have them in operation at the next show. I can say that Nelson Pass's XA 30.5 amplifiers performed brilliantly, and for some, that may be all they need.
4.) Running the phono stage through the digital Xover - a serious no no. Yes? The differences in character between the output of the CD player and the turntable were significant, with the turntable performing exactly as one would expect it to in an all analog system: It was a bit more true to life, exhibited really fine texture and inner detail with a deeper and wider sound stage and more palpable presence. Again, with conversion occurring at a super high bit rate, the throughput is utterly transparent.
The Granada is an attempt to bring Feastrex drivers into the mainstream. The extent to which we succeeded in preserving the original character of these glorious drivers while relieving them of the duty of driving low frequencies is the extent to which we have succeeded.
1.) We added woofers and a rear firing tweeter to a driver created for use by itself in a dedicated enclosure.
2.) We used a digital crossover
3.) We used solid state amplification for top and bottom.
4.) We ran an analog turntable's phono signal created with an expensive arm and cartridge through a digital crossover.
So like Klipsch in the 60s, perhaps we should have named our speaker "The Heresy". But here's the rub: every approach has its compromises and drawbacks. Let's address these one by one:
1.) Woofers and rear tweeter vs. single driver only:
In an open baffle, the single driver approach is a non starter - no bass to speak of. We decided that an open baffle has certain advantages. The main one being - no box means no box colorations. Another is that since an open baffle radiates in a figure eight pattern, there is a null in the output at the sides of the speaker. This means less excitement of bass nodes in the room.
We measured the speaker 36 times in the vertical plane and 36 times in the horizontal plane for axial response, listening window response and overall power response. In order to balance the rear high frequency response with the Feastrex driver a rear tweeter was a necessity. The opening at the rear of the Feastrex's frame is small and there's no rear facing whizzer cone. Since the tweeter is facing rearward it has no effect on the character of the main driver facing forward.
2.) Digital vs. analog crossover. At first glance it would seem that an analog crossover would be superior to a digital crossover as the analog signal is not chopped up and rearranged by the conversion process. In fact I resisted using the digital crossover myself until I heard and understood what it brings to the table.
Here's what you can't do with an analog crossover: You can't perfectly match drivers. (BTW, the engineer was amazed at how closely the two D5e II drivers were - not as close as machine made cones, but way closer than he expected - a testament to the precision and accuracy of Mr. Teramoto's handiwork). You can't perfectly time align the drivers. You can't use 4th order crossovers (not in a practical sense at least). You can't contour precise frequency bands, and you can't adjust for actual room response.
Here's what you get with a digital crossover: Absolute rock solid imaging with instruments in real and proper position and proportion to one another (Outside of the Feastrex D5e II themselves, this is largely what gives rise to Jonathan Valin's statement that the Granada had "more sheer you-are-there realism than anything else at the show". There were of course other factors involved as well, but I attribute a large portion of that to the Xover.), the ability to contour the Xover to the best advantage of the drivers, and the ability to go into any room anywhere and know that you can make the speaker perform to its maximum capabilities. All information is processed in real time at 48 bits - more than enough to have virtually transparent throughput.
3.) Solid state amplification used top and bottom. We were hoping to get the Maekawa amplifiers in time for the show, but they only arrived after the show began and we did not have time to adjust the speaker for them. Greatness is worth waiting for, and we will have them in operation at the next show. I can say that Nelson Pass's XA 30.5 amplifiers performed brilliantly, and for some, that may be all they need.
4.) Running the phono stage through the digital Xover - a serious no no. Yes? The differences in character between the output of the CD player and the turntable were significant, with the turntable performing exactly as one would expect it to in an all analog system: It was a bit more true to life, exhibited really fine texture and inner detail with a deeper and wider sound stage and more palpable presence. Again, with conversion occurring at a super high bit rate, the throughput is utterly transparent.
The Granada is an attempt to bring Feastrex drivers into the mainstream. The extent to which we succeeded in preserving the original character of these glorious drivers while relieving them of the duty of driving low frequencies is the extent to which we have succeeded.
Show Images
An externally hosted image should be here but it was not working when we last tested it.
An externally hosted image should be here but it was not working when we last tested it.
An externally hosted image should be here but it was not working when we last tested it.
Thank You, Chris. The rear firing tweeter is necessary to balance the power response of the Feastrex drivers to the rear. As I mentioned above, the ideal dipole radiates in a figure eight pattern. Without the tweeter the response pattern would be off. The tweeter is passively crossed over. The speaker itself remains a two way as the tweeter can be considered as an ambient aid rather than a direct radiator.
I'm glad to see you followed up on my suggestion for AE/Llambda bass drivers
Looks like good execution and the best way to deal with the heat from the field coil.
dave
Outside of Harman, this is the 1st documented instance of someone taking sufficient measures to get a FR metric that correlates with what we hear (at least by what Floyd Toole documents in his book). Good on you Joe.
dave
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