I doubt it's much lower. To my ears, it's about 93 dB, wheras the R-1 is supposed to be 95. Speakercity also have the Hi-Vi Research RT-2 Ribbons close-out priced for only $31 a piece...I bought a pair of those too. They aren't flat though, and will need a gradual rolloff below 10kHz to bring the top octave up. By contrast, the Infinity Emit seems to have nearly the same dispersion as a one inch dome, and even more surface area. A pair of the Infinitys in parallel might be a better approach than a single R-1, at least where money is concerned (i.e., more surface area and higher efficiency). To my ears, it's as good as the circular ribbon Genesis uses, and that's saying a lot!
If you're wanting several midwoofers in series-parallel, then of course your cost will go WAY up. I still would like to suggest the Bottlehead kit. You could even modify it by using a different tweeter, like a Focal dome (or that pricey new one Kharma uses), a Raven, a Fostex, an Eton, or whatever. As is, though, I bet it would more than suit your needs.
If you have more money than sense, you might want to buy a pair of the new Accuton DIAMOND DOME tweeters, for $2500 a piece!! I bet they are just killer! Supposed to be pistonic to 100 kHz!!
Actually, the 8 AWG North Creek air coils have the absolute lowest DCR of any inductor on Earth, and DCR is always a direct function of the cross sectional area of any conductor. The main advantage that Solo's or Alpha Core's foil-coils have, is in reduced skin effect, since the entire conductor is a ribbon, so it conducts electricity entirely on its "skin". However, their largest ones are only 12 AWG, so their DCR is radically higher than that of North Creek's 10 or 8 AWG air core coils. Solen even makes 10 and 12 AWG heptalizt coils that are supposed to be magnificent.
In one of my projects, I went from a 14 AWG Solo CFAC inductor (identical to, and predating, Alpha Core), to a 10 AWG North Creek, and every aspect of performance improved (that driver is a Dynaudio 15W75-04). |
Lots of good dialogue here Noquarter. Thank you. If you are interested in seeing an interesting site on this series crossover "thing", please go to
http://home.iprimus.com.au/gradds/index.htm
It may just keep you busy for a while.
You are correct in what you say about the North Creek coils. It is just obvious that their 8 or 10 gauge coils would have a lower DCR than AlphaCore Goertz, whose largest are 12 gauge for copper, 14 gauge for silver. Don't know why I went along with their statement. It should be more than apparent. Perhaps they offered this up before these North Creek coils were introduced. Not sure when that was, but the last time I bought North Creek coils(1996) their largest wire gauge was 12. I am not a fan of the Solen heptalitz coils, I find North Creek much better sounding. And the Goertz would give a sound of another color, whether it is preferred is a matter of personal taste. I will need to check out North Creek to see how expensive these larger gauge coils are. Again, by running the mids flat out, I can save that expense.
I know that I prefer the sound of the mids without a coil in the circuit. Presuming that the driver is of the requisite quality and robustness, it is a no lose proposition. I would like to hear an argument as to what a series network could offer over having nothing in the path of the midrange.
I would not install more than two midranges in each speaker. As you pointed out, the cost of going crazy in this area adds up fast. I am leaning towards the two midranges, despite my liking the time alignment(one midrange) my Coincident speakers feature. Their sound has more than sold me on the arrangement.
Accuton drivers are not new. I first came across them in the early 1990's. While I didn't spend a lot of time with them, I can describe the sound as very smooth and natural. While pricey, they are not as expensive as Raven. I would not use Accuton drivers in this project because they are lower in sensitivity(usually 88 - 90 dB/2.83 V), and are not physically robust. I used to work with alumina(electronic substrates, paste, and I also used to tape cast it), and while very hard, it is very brittle. I have seen these drivers shatter rather easily in a speaker that was involved in a move.
In researching the EMIT-B ribbons you recommended from Speakercity.com, I found the sensitivity was too low for this project @ 90 dB/2.83 V. Price is good at $40. What do you think of the sound? I have not been around an EMIT driver since 1988.
The Ravens are available in sensitivities of 96 and 98 dB/2.83 V. Very high, but they are very expensive. Not sure if I want to put this kind of money in a speaker when I will be doing the cabinet work myself. While I have no problem with the construction of the box, I have never done any finishing. If I am going to build an expensive speaker, I kind of think it deserves the "living room" look.
I will also look into Cabasse drivers. I once helped a friend in a D'Appolito project using these drivers. They feature some highly sensitive drivers in their line. Sound is fast, and clear. Maybe not as laid back as I might want. We'll see. Following along Sean's recommendation, they offer some horns, which I should investigate. 108 - 110 dB/2.83 V sensitivity. Interesting.
Needless to say, the diamond domes are out of the question. Maybe Liz Taylor would be interested...
I will check out Bottlehead.com today. Thanks for steering me to their site.
My only listening of Fostex drivers were in a speaker that had no grunt to me. Kind of shallow. Lively and able to play loud, just that I prefer a little more "blood and guts" to the sound. Maybe I am selling them short. Have you heard them in a better light?
I am on record at Audiogon of not being the biggest fan of Focal tweeters. They can play loud and clean, just hard on my ears. But, I have really been impressed by the sound of Osborn speakers, which use all Focal drivers. When driven by more sedate electronics, such as Electrocompaniet, I have to admit the sound is first rate. Their mids and woofers are right up my alley, however. Available in high sensitivity or high impedence versions. So, that is why I will probably go with them or Cabasse.
Again, this is a wonderful dialogue. Something about the speakerbuilding hobby that I can never get tired of. Thank you! |
Well, good luck in your project. I'll check out that iprimus site.
I never said Accuton was new; I said the Diamond dome was new. It will be interesting to see which manufacturer uses it first.
The sensitivity for the Emit-B seems higher than 90dB to me. The sound is fantastic imo; far more detailed and dynamic than I was expecting. It's a modern unit, with Neodymium magnets, so it's bound to ouperform those Infinity units you heard in the 80's.
Also, the published sensitvity for the new Raven R-1 is only 95 dB, the higher sensitivity is for the previous models (now discontinued). I think a pair of the Emit-B's in parallel would equal or exceed that sensitivity. Keep in mind that neither of these small tweeters will work below 3kHz.
As I've said before, if you absolutely want to run a midrange driver "flat out" you should consider a fullrange speaker like a Lowther or a Fostex. I've not heard the Fostex drivers, but their specs look more than adequate for their price, even a match for the Lowthers. The 8 inch model has nearly 100 dB sensitivity!! A series crossover isn't quite the same thing as running a fullrange driver with no crossover at all, imo.
Have you looked at Madisound's site, under Fostex drivers? Also, their ribbon tweeter looks about as good as the Raven R-1, and the Fostex one is only around $100...half the price.
I had thought that your goal was to throw something together for your secondary system, and to experiment; I didn't realize you wanted it to be a "statement" project. Those can be difficult and time-consuming...and let's face it, neither of us is a world class designer.
I, too, am no fan of Focal tweeters. Problem is, if you want to use only one tweeter, and decide you'd rather have a dome than a ribbon, the Focals are the only ones with high sensitivity, without horn loading.
The problem with using compression drivers and horns, is that you wind up padding them way down to match the lesser sensitivity of the midwoofers, so a lot of power gets wasted in the crossover, and I'm not sure it's even possible/ideal to use series crossovers in such an application.
I think you'll find, that unless your living room exceeds perhaps 7000 cubic feet, you won't need a speaker higher than 100 dB sensitivity (even with only a 3 watt amp)...and in any case, without the proper room treatment and placement, you'll hear more of the room's echo than you realize, imo. |
Thank you Noquarter. You have graciously provided more information than I could ever expected. I am endebted to you. If you don't mind, I will get into contact with you at some point outside of this thread to further discuss some things.
You are absolutely correct in raising the issue of this being a secondary speaker project or a "statement". To be honest, I easily fall into this trap. I go way overboard. A very negative byproduct of my love of the speakerbuilding hobby. It is by far my favorite facet of audio. In fact, spurred on by my thinking of the past few days and your assertion, I discussed this with my girlfriend last night. This was supposed to be a secondary speaker. I really should just buy something along the lines of 4 Vifa 6.5" midranges and 2 Vifa D26 tweeters. Run the mids with nothing in the circuit, and connect a not overly extravagant film and foil cap on the tweeter leg. Throw them in a reasonably well constructed box, wire them up and call it a day. Perhaps, I should revisit that for this project.
But, I have still haven't ruled out doing something where I can build my speakerbuilding skills/experience further...
One of the higher sensitivity Ravens I was referring to was the Raven R-2(there is another). If I do decide to use one, hopefully they have not been discontinued. I did hear the Raven tweeter in a few newer designs from Acarian systems, and my initial impressions are quite favorable. If this tweeter really can offer me this detailed, yet smooth sound, coupled with this level of output, it is definitely something that would be on my short list.
Good points on the horns. That is actually what I originally envisioned. Aim for a sensitivity from 92 to 95 dB/2.83V.
As far as the Fostex drivers are concerned, I did visit the Madisound site. While they look good on paper, as I previously stated, my real world experience with them was in no way favorable. Yes, their sensitivity is high, and their operating range more than extremely broad. Just that if I am going to build or buy a loudspeaker, it better not sound like that. Able to play lively and loud, yes. But to my ears, along the lines of the way a clock or table radio sounds. No sock or punch. AT ALL. My hope was that you would have also had heard Fostex. To tell me whether what I heard was just a poor execution of the driver, or an affirmation of this being what it sounds like.
The fact that we view Focal tweeters in the same light shows me that we do think in parallel ways, at least in this area. And, also in our belief that a driver with no crossover should be better than one in a series network.
So far, the only speakers I have heard with the series crossover fresh in my memory is Roman Audio. Very, very impressive. Yes, this hyped up, patented DiAural crossover is actually just a series network! Just that it contains no capacitors. SonusFaber has supposedly used in the past with a tweeter, so how enforceable is the patent?
I also heard Fried a lot in the past, but would need to hear them with my current ears/mind, and with the type of gear I use.
Again, thank you. |
You are quite welcome. I've always felt that the problem with "highend audio", is that there aren't more folks like us. I have to laugh, when I think of all those consumers that take loudspeakers and room acoustics for granted, and instead pay more attention to "tweaks", like gold-plated titanium rollerballs, etc.
I look forward to hearing from you in the future.
Did you happen to hear that Alon Statement speaker? it's the only one I'm aware of that uses the Ravens, they're the smaller R-1, and it uses 6 per channel I believe.
The speaker I'd like to hear, is that Impact "Airfoil" bending wave model...supposed to be a new take on bending wave drivers, uses them in a line array, fullrange down to about 100 Hz.
Does the Coincident speaker model you have not use the Seas Excel magnesium coned midwofers? I thought they all used those magnesium cones...the thing with them, is that you can never get rid of that ringing, even with an infinite slope crossover. It's just that it's essentially inconsequencial in the final speaker, since the ringing still is mostly focused on-axis.
Metal cones do have an efforteless controlled snap to the sound, I have to admit. I own an aluminum-coned Seas, for yet another project. The corresponding magnesium model rings somehwat louder than the aluminum, though...but that solid copper phase plug in the Excel versions sure looks awesome.
In my opinion, the 8 AWG North Creek coils get very close to the performance of not having a coil at all. However, they aren't exactly the same, obviously.
No, I've not heard any of the Fostex line. I'm curious if the driver you heard was mounted on a baffle in a finished design, and if so, which model was it? Was it any of the current ones in production, as listed on the Madisound website? Did it use a rear-loaded horn, a front-loaded horn, or both?
I'm trying to decide which 4 inch midwoofers to get, for the tiny "monitor" project with the Emit tweeters I bought. There is an older Vifa 4 inch polypropylene cone that has an EXTREMELY smooth rolloff, and might work with no crossover: the P11WG-00-08.
I may try using this one myself, but according to the Solen catalog, it will only yield an F3 of 60Hz, and I was hoping for a tad lower.
If I can't find a treated paper 4 inch cone with a low enough Fs, I may try and use that poly-coned model I mention above. It's just that I'm getting tired of the sound of poly cones. They have the advantage one you go bigger than 6 inches diameter, but not for 4 inches diameter, imo.
All would be fine, if Audax's new "polymer chassis" line, didn't feature back plates WITHOUT vent holes for the pole piece. Why anyone would ever buy midwoofers without vented pole pieces is beyond me. And they even charge as much for this new polymer line, as they did for the premium zinc-chassied line. That just seems outrageous to me.
I own 6 of those too (they're spectacular imo), it's the treated paper version of those found in the Pipedreams. They're discontinued now, so they only sell the carbon fiber model, again as found in the Pipedreams. |
