I don't get this needing a big room thing ... the size of the listening space has never been relevant for creating an extremely intense listening experience for me ...I have had my body slammed by Kodo drummers 30 meters away, to get a HiFi setup to get anyway near that, the room has to really big. Perhaps not as big as the concert hall but at least way bigger than my home office
Perhaps the thing is that a lot of hifi bass is very sloppy and blubbery - it reminds me of a 50's Cadillac going at speed along an undulating road - the motion of the body is only very vaguely related to what the road is doing.
30 years ago I realised that miserable 8" dynamic drivers could correctly convey the punch and intensity of a solid drumkit workout, say - if all the right things were done. A lot of these audiophile bass setups, to me, sound quite ridiculous in the flesh - show pony stuff ...
Personally, when a system works well, it allows me to walk right up to the front of an individual speaker in full roar - perfectly comfortably, I don't need to tense my hearing system to do this, I can let the full wash of the sound just go straight in, without any mental filtering required.
Of course, this doesn't work for most - it steadily becomes more unpleasant the closer you get ...
Of course, this doesn't work for most - it steadily becomes more unpleasant the closer you get ...
Yeah, gotta agree with that. After the day I sat in a friends car that had 4x12" subs and kilowatt amps. That was intense! Small car, but not a small sensation. It doesn't just sound dangerous, it feels dangerous.
Ya just gotta live sometimes ...Yeah, gotta agree with that. After the day I sat in a friends car that had 4x12" subs and kilowatt amps. That was intense! Small car, but not a small sensation. It doesn't just sound dangerous, it feels dangerous.
Good systems are about precision at all volumes - I want to be able to put on, say, AC/DC at volumes which are pulverising the house, but the sound is totally clean - I can hear every subtle element of what the drummer is doing with tonality fully intact. And, immediately after, put on a super low key ambient style music track at whisper soft volume - and still have the latter musically draw me in ...
Yeah, yeah, I know it sounds funny, but I walk away and I find a sweet spot as far away as I can walk in the room. That is when the speaker comes alive. Is everyone else sitting as close as they can to their horns?
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Rembember, it is pretty logical that a horn tweeter needs a tweeter sized horn, not a midrange sized horn. If you use a midrange horn for your tweeter, you will miss out on a lot of good stuff. If you insist on using Radian 745 Be all the way up, then get another pair of Radian 745 Be with smaller horns. And then you add another small ribbon driver horn with a Raal or a Transmission Audio ribbon!
Maybe not completely broke. My pal Gary Pimm has built a really cute all-wood horn for the Radian 475 (the little one-inch-exit driver). It's a 1 kHz JMLC with a 270-degree roundover (yes, really), but is still only a foot across. He's offered to build more of these for anyone that wants them (and at a reasonable price, too).
The Radian 475 is available with a beryllium diaphragm; that would easily take it well beyond 20 kHz, which then makes it a decent supertweeter. If you took that path, the optimum crossover between the AH425/745NeoBe and the 475Be would be in the 5~6.4 kHz region. You then have separate MF and HF horns, substantially lower IM distortion (thanks to band-splitting), and good dispersion through the working range.
Not really that original; that's the MF/HF Be/Be horn setup of the JBL DD66000 Everest, which has pretty good HF response and pretty good dispersion. The Everest also has paired 15" woofers, and is not aimed at American audiophiles who are into low-efficiency speakers. (The primary market of the Everest series is Asia; it was first available in Tokyo, and it took many years to be also offered in the US market.)
In an example of convergent evolution, there aren't that many ways to build a high-efficiency speaker. If you want the highest efficiency possible (more than 105 dB/meter), then you need lots of room for a straight bass horn. If you can live with the lumps in response (which don't sound as bad as they measure), a folded bass horn. If you don't have the room and the available matched room corners, then it's direct radiators, most likely in an array.
Efficiency steps down several dB for each space-saving alternative, but it's still 10x to 20x higher than the mainstream high-end audio average of 87 to 90 dB/meter (the typical efficiency of 7 to 12-inch woofers, and dome tweeters).
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Regarding the question of the need for a tweeter above the 745NEO/be:
For me, the 745NEO/be sounded gorgeous without a tweeter, just what the doctor ordered for many of the recordings I listened to. The subsequent addition of the G3 ribbon brought a breath of fresh air to recordings with a clean and properly balanced top octave.
Looks like it would be a simple matter to eq the neo/be for use without a tweeter, but first I'd like to try using it with a ribbon for those nice clean recordings, and simply go without the tweeter on the others. Lots of options though…we'll see.
Aluminum better tone than Be? Not in the 745…no how, no way. Other way around--the neo/be is all about tone. But to be fair, what I heard involved a change of two variables, both the magnet and diaphragm material. Lynn said the neo/alu was much better than the ceramic/alu, with no lack of HF extension so that was an attractive option, but have heard a lot of aluminum drivers already and wanted to try beryllium.
All of the Radian drivers will be retrofittable with beryllium diaphragms once they start offering replacement units. You can't interchange diaphragms for ceramic and neo motors, though -- the diaphragm frame for the neo driver is much smaller in diameter, to match the size of the magnet. My advice: if you don't want to spring for beryllium, at least get the drivers with neo motors.
For me, the 745NEO/be sounded gorgeous without a tweeter, just what the doctor ordered for many of the recordings I listened to. The subsequent addition of the G3 ribbon brought a breath of fresh air to recordings with a clean and properly balanced top octave.
Looks like it would be a simple matter to eq the neo/be for use without a tweeter, but first I'd like to try using it with a ribbon for those nice clean recordings, and simply go without the tweeter on the others. Lots of options though…we'll see.
Aluminum better tone than Be? Not in the 745…no how, no way. Other way around--the neo/be is all about tone. But to be fair, what I heard involved a change of two variables, both the magnet and diaphragm material. Lynn said the neo/alu was much better than the ceramic/alu, with no lack of HF extension so that was an attractive option, but have heard a lot of aluminum drivers already and wanted to try beryllium.
All of the Radian drivers will be retrofittable with beryllium diaphragms once they start offering replacement units. You can't interchange diaphragms for ceramic and neo motors, though -- the diaphragm frame for the neo driver is much smaller in diameter, to match the size of the magnet. My advice: if you don't want to spring for beryllium, at least get the drivers with neo motors.
I measured the TD15M's first. Results were very close to the published specs.
Different story with the GPA's, though. I wasn't really surprised, because the published parameters for Altec drivers over the years have been all over the map. GPA uses the same soft parts (cone, surround, spider) for their alnico versions of both the 416 and 515, so the only difference between the two drivers is the motor -- 2.44 lbs of alnico for the 416B vs. 4.4 lbs for the 515C.
For the 416-8B, Qts was consistently .27 for one driver and .28 for the other. Fs was about 21 Hz, and Vas was about 800 liters.
Both 515-16C drivers, after being run-in for 90 minutes with a 20 Hz sine wave, had an Fs of about 18 Hz, Qts of 0.20 and Vas of between 1000 and 1100 liters.
Tests were made using Limp and an "official" Arta test box. Not much to argue with there.
These are amazing drivers, and I will have a lot more to say about them soon enough…but gosh, it's getting late.
Gary Dahl
Think you repeated some stuff from earlier no problem. The neo alone will make a significant improvement. The Al ceramic is one that you described as no way better than Be Neo. But surely the 745 Neo Al versus Be is the comparison to be made, and allows as I stated a Be step up from the much cheaper Neo AL ( that some may prefer) They run very close on test until you hit the 5kHz to 6kHz and upwards. So with a supertweeter you could avoid the huge premium for the Be at least as a starter. Then still go for Be if it does not satisfy.
To take Lynns post - You could use the Be 475 /horn as the supertweeter and the Neo Al /horn as the mid treble.
Not sure I would have believed this until last weekend I heard aussie Mark Lenehan ML-1 ref mini monitors, playing loud in a small room, with pinpoint 3D focus and tight powerful bass. Guitar felt like in your own hands. I just marvelled at the physics of it.
ML1 Reference Specifications
There are many minimonitors that will do that, and its great because small room guys can really get in on the super fidelity reproduction on less $, They can easily add a sub.