Ah, you're the guy who designed the Griffin - all makes sense now.
The more I look at the pics, the more sense my ideas make, so I'm grateful for your posting yours here. It's good to have some validation from a designer who's work I have admired in the past.
The system I mentioned in the other thread I'm putting together has some conceptual similarities, and it will look very similar, but will be all tube powered for my small room, except for the subs. Many of the ideas I plan to use in mine evolved from reading about the Griffin, and I wanted to incorporate my fave high efficieny drivers into a vertically symmetrical array. I won't derail your thread any more, but may post a link to the original rambling thread I made.
The more I look at the pics, the more sense my ideas make, so I'm grateful for your posting yours here. It's good to have some validation from a designer who's work I have admired in the past.
The system I mentioned in the other thread I'm putting together has some conceptual similarities, and it will look very similar, but will be all tube powered for my small room, except for the subs. Many of the ideas I plan to use in mine evolved from reading about the Griffin, and I wanted to incorporate my fave high efficieny drivers into a vertically symmetrical array. I won't derail your thread any more, but may post a link to the original rambling thread I made.
Hi StigErik,
first of all, congratulation. A real impressive work (and weight).
For comparison purposes I just felt free to add a picture of my "big" ones
(right side only shown), which are not really comparable to your honeys.
The weight of my big speakers is round about 110kg. The bass cabinet is made up of 50mm MDF plus additional bracings inside.
The chassis I've used are:
Bass: Isophon PSL385/400 GJW
Bass-Mid: Dynaudio 17W75
Mid: ACR FS21RP
Tweeter: Technics TH800
The bass chassis by the way is a modified version - the so called Guido J. Wasser (GJW) version - where the weight of the membran is doubled (possibly by using some sort of coating since I've never seen the unmodified version). All the way back, at the time I bought those chassis, I paid about 1300,- DM (or approx. 700 US-Dollar at that time) for a single chassis.
The tweeter you possibly can't get hold of any more. The TH800 was basically an ultrasound transducer for frequencies up to 100kHz until it was "discovered" for HiFi-use.
About the FS21RP, it appears to be from Fostex instead of ACR by now. Can't tell which one is/was the original manufacturer of it.
The crossover is still passive (for more than 15 years by now)) but I've enough space left over in the back of the speakers for any "activation" tendencies (if there will be any in the future ...).
Oh, besides the big one you'll see to the left a "360 degree" speaker with the chassis pointing to the ceiling, made up of a soft-dome tweeter and a 6" bass-mid with the BR duct pointing to the floor.
Furthermore you see on the far left side a TQWT with a Visaton FRS8 (just google for "Cyburgs Brick" ).
first of all, congratulation. A real impressive work (and weight).
For comparison purposes I just felt free to add a picture of my "big" ones
(right side only shown), which are not really comparable to your honeys.The weight of my big speakers is round about 110kg. The bass cabinet is made up of 50mm MDF plus additional bracings inside.
The chassis I've used are:
Bass: Isophon PSL385/400 GJW
Bass-Mid: Dynaudio 17W75
Mid: ACR FS21RP
Tweeter: Technics TH800
The bass chassis by the way is a modified version - the so called Guido J. Wasser (GJW) version - where the weight of the membran is doubled (possibly by using some sort of coating since I've never seen the unmodified version). All the way back, at the time I bought those chassis, I paid about 1300,- DM (or approx. 700 US-Dollar at that time) for a single chassis.
The tweeter you possibly can't get hold of any more. The TH800 was basically an ultrasound transducer for frequencies up to 100kHz until it was "discovered" for HiFi-use.
About the FS21RP, it appears to be from Fostex instead of ACR by now. Can't tell which one is/was the original manufacturer of it.
The crossover is still passive (for more than 15 years by now)) but I've enough space left over in the back of the speakers for any "activation" tendencies (if there will be any in the future ...).
Oh, besides the big one you'll see to the left a "360 degree" speaker with the chassis pointing to the ceiling, made up of a soft-dome tweeter and a 6" bass-mid with the BR duct pointing to the floor.
Furthermore you see on the far left side a TQWT with a Visaton FRS8 (just google for "Cyburgs Brick"
).Attachments
buggsson said:
Currently - 70 / 500 / 2700 Hz
I started out with 100 / 500 / 2500 Hz
I have found that the large 18" woofers have some colorations in the 100 Hz area, and that the 8" mid-woofers sounded cleaner.
Also - the tweeter may sound a bit stressed with too low crossover. On the other hand, the 5" Excel has a steep increase in THD above 2500 Hz. I've tried both 2500 and 3000, both with their own problems. 2700 seems like the best compromize for now.
Since I use linear-phase digital x-overs, there is no relevant crossover slope like 24 dB/octave or whatever. The 70 hz crossover is rather soft, I would guess close to 24 dB/octave. The higher crossover point cut off much steeper. The 2700 crossover is very very steep, like a clifff almost...
I do in fact use the same woofer size as the Griffin - 18-inch. The Griffin model 1 is using one 18" in reflex cabinet. Here I use two, in closed box. Closed box does not produce as much maximum SPL as reflex, so I had to use at least two drivers to compensate for that.jpetek said:
The tweeter I use is not really a ribbon, its an Air Motion Transformer. I did compare it to other drivers, especially the Philips RSQ8P (obsolete), and B&G Neo3. Both are pretty good above 5-6 kHz, but cannot rival the Mundorf AMT 2340 I'm using. The Mundorf is much better below 4-5 kHz than any of the other two. The Mundorf is also more well behaved off-axis, and has far lower distortion than the other two.
The most important thing is that the Mundorf AMT is the best tweeter I have ever heard. Its frequency response is a bit tricky, especially with a passive filter, but if you can handle it - there is nothing that comes even close I think.
I tested a larger Mundorf AMT as well, but the driver was still a prototype with some issues that need to be corrected before it could be seriously considered.
phase_accurate said:
Yes, of course.
Since I use a kind of DRC for the bass below ~200 Hz, this also requires the listening position to be fixed within the room.
When I do serious listening, I always use the same listening position. I have a dedicated listening room as well.
For casual background music I have an other setup in my living room... which sounds like crap in any listening position...
Great looking system, Stig! Nice to know it sounds like electrostatic with more dynamics. =)
Nice design, very well executed.
On a side note, I do agree you with on the new ICEpower amps. I've been playing with the new 124ASX2 Modules and think they sound great. A very subtle and nuanced amp. Very neutral and plenty of power. (I also have access to the modules, but can't sell them - yet).
Nice design, very well executed.
On a side note, I do agree you with on the new ICEpower amps. I've been playing with the new 124ASX2 Modules and think they sound great. A very subtle and nuanced amp. Very neutral and plenty of power. (I also have access to the modules, but can't sell them - yet).
Stig,
Nice to see a fellow Norwegian doing awesome stuff (well, I am only half norwegian, but hope to still make a visit to the homeland someday...).
Anyways, can you tell us a little more about how you approached your subwoofer design and if there is any other info on the web you woudl recommend? I have seen a bit on running subs below system FS, but not much I can latch onto. Is it just a matter of building a smaller than ideal cabinet and then using test equipment to determine the "in cab" FS? Also, if you were to take a stab at such a demanding project again starting from scratch, would you still pick dual 18s or think about quad 12s or 15s like a Beyma 12LX60 which is supposed to perform extremely well under its FS?
Hope I am not acting too needy here, but your approach to the subwoofer is one I don't see discussed here very often and when it does it gets all crazy and lacks any real world tests by advanced DIY'ers like yourself. Again, an awesome project.
Nice to see a fellow Norwegian doing awesome stuff (well, I am only half norwegian, but hope to still make a visit to the homeland someday...).
Anyways, can you tell us a little more about how you approached your subwoofer design and if there is any other info on the web you woudl recommend? I have seen a bit on running subs below system FS, but not much I can latch onto. Is it just a matter of building a smaller than ideal cabinet and then using test equipment to determine the "in cab" FS? Also, if you were to take a stab at such a demanding project again starting from scratch, would you still pick dual 18s or think about quad 12s or 15s like a Beyma 12LX60 which is supposed to perform extremely well under its FS?
Hope I am not acting too needy here, but your approach to the subwoofer is one I don't see discussed here very often and when it does it gets all crazy and lacks any real world tests by advanced DIY'ers like yourself. Again, an awesome project.
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