Re: Re: Talk to Radian...
Don't think he was dismissing the compression driver, just that if you ship the speakers to have it reconed, no need to ship excess weight around.
Sheldon
Magnetar said:
What's wrong with the compression driver?
I prefer paper cones over plastic and cast frames over stamped!
I just bought a pair from him for $ 200.00 - the compression drivers are worth more then thatAt least to anyone looking for a good new 1" aluminum compression driver
Don't think he was dismissing the compression driver, just that if you ship the speakers to have it reconed, no need to ship excess weight around.
Sheldon
Magnetar said:
Smart buy. These are the same coaxes that Mike of Radian uses at home. Don't see how you could go wrong with these!
Speaking of Mike - he told me a funny story - the folks at Radian wanted to see just much power it would take to destroy the 12" coax. Well, it finally failed with a 12 kW amplifier, with 147 dB SPL coming out of the speaker!
Been doing a little research about 18" woofers for bass-dipole use. My initial reaction is a big "huh" - not quite what I expected.
Most of 18" drivers appear to be designed for subwoofer-only use, with very heavy cones, ranging from 140 to 200 grams. The sheer magnitude and roughness of the peaks in the 500 Hz to 2 kHz range make it obvious that 24 dB/octave active crossovers are typically used with these drivers, so midrange response is of no concern at all.
By contrast, the 15" drivers I'm looking at, the 18Sound 15NMB420/15MB700 twins have 73-gram cones, and the 18Sound 12-inch 12NDA520 has a 36-gram cone. The only general-purpose 18-incher I've come across (so far) is the Beyma SM-118N, with a 123-gram cone, and surprisingly smooth midrange response.
I'm starting to understand why 18-inchers are considered special-purpose drivers, unlike 15's, which have many different applications.
Lynn Olson said:
He has one other pair AFAIK - I sent him an offer of 100 a piece before the auction ended and he accepted it when it was over.
I think they'll make a nice little monitor or a really good 200 up mid/tweeter in a big system
Now I have like 12 pair of coax's and haven't expirimented with half of them
The JBL 2242's are the best 18's I've tried, a real nice driver.
comp no problem at all...
I was looking into buying a set of 508's some years ago and contacted Radian to see if they could advise if they would do what I wanted. They (one of the owners) told me to buy them if they were the plastic cone version not the paper.
At $75.00 each I figured that with the cast basket you could have them reconed to the plastic cone and they would still be a good deal. I only mentioned removing the comp motor to save on shipping cost if you sent them back to recone over to plastic. Plastic over paper goes against my grain but that is what I was told. The comp drivers sound great and are worth over $75.00 each easy used. Regards Moray James.
I was looking into buying a set of 508's some years ago and contacted Radian to see if they could advise if they would do what I wanted. They (one of the owners) told me to buy them if they were the plastic cone version not the paper.
At $75.00 each I figured that with the cast basket you could have them reconed to the plastic cone and they would still be a good deal. I only mentioned removing the comp motor to save on shipping cost if you sent them back to recone over to plastic. Plastic over paper goes against my grain but that is what I was told. The comp drivers sound great and are worth over $75.00 each easy used. Regards Moray James.
The Radian 508 coaxial is one of the most musical drivers I have ever heard. I own a pair; GM calc'd a MLTL four years ago for me so I could try it. It was a BIG damn load, but man did it ever sound nice. I knocked down the cabinets before we moved, but I have the drivers. I have read of a few people who really, really like the Radian 12 in the Galante Symphony, and so they would sound all the better on an open baffle. Brian Galante will cobble up his XO for either of these two units. If I were to make a play for this tonight, I would get the Radian 12 coaxials. These two speakers have the vintage Tannoy gestalt, owing to their common genetic heritage, as both cleft off the earlier Altec USA genome, the Radians, to me, sounding far, far more musical.
Recommended.
Recommended.
Nice to see the Radian love-fest here and in the other thread. From the parallel discussions, the Radian coax or the Radian 850-PB compression driver both look like excellent choices, especially for a dipole with high efficiency, low distortion, and very wide dynamic range.
The scene here in Northern Colorado (well, north of Denver anyway) is Oris/Azura horns with Lowther/AER drivers, Klipsch bass, and Eimac transmitter-tube SET amplifiers with prewar Telefunken driver tubes. Although stunningly good - way better than anything commercial, that's for sure - it isn't quite for me. I like the high-efficiency dipole sound a lot better, and if - that's a big if - the HF section can keep up, that's what I want.
The sound I don't want is Altec A7 or 604 Duplex - but the large-format horns seem to be quite another matter, with much more relaxed, effortless, and sweeter sound. The sizzle and zip of 1" compression drivers just isn't there - and if a supertweeter is needed for that last bit of HF extension, I'm OK with that.
The scene here in Northern Colorado (well, north of Denver anyway) is Oris/Azura horns with Lowther/AER drivers, Klipsch bass, and Eimac transmitter-tube SET amplifiers with prewar Telefunken driver tubes. Although stunningly good - way better than anything commercial, that's for sure - it isn't quite for me. I like the high-efficiency dipole sound a lot better, and if - that's a big if - the HF section can keep up, that's what I want.
The sound I don't want is Altec A7 or 604 Duplex - but the large-format horns seem to be quite another matter, with much more relaxed, effortless, and sweeter sound. The sizzle and zip of 1" compression drivers just isn't there - and if a supertweeter is needed for that last bit of HF extension, I'm OK with that.
FYI
You can get Radian 508/2B "ceiling" speakers at Parts Express, complete with Radian designed/built XO. As I already had the drivers, Mike at Radian, great great guy BTW, offered that if there were no other avenues, he would see to it that I got a pair of the "better" XO which had been tweaked to perfection over the years, sayeth he. Soon after I took him up on the offer, they arrived. Well, they are pretty darn fine. The PE price with the XO is $240 and I think this is pretty good as well. I have pretty much decided to build my new pair with the Radians, as I know the house sound, and all the rest.
You can get Radian 508/2B "ceiling" speakers at Parts Express, complete with Radian designed/built XO. As I already had the drivers, Mike at Radian, great great guy BTW, offered that if there were no other avenues, he would see to it that I got a pair of the "better" XO which had been tweaked to perfection over the years, sayeth he. Soon after I took him up on the offer, they arrived. Well, they are pretty darn fine. The PE price with the XO is $240 and I think this is pretty good as well. I have pretty much decided to build my new pair with the Radians, as I know the house sound, and all the rest.
Lynn Olson said:
Well- with a good large format compression driver I see more of a problem of the dipole bass keeping up with the compression driver.
My current 'horn' system is twin backoaded 15's (picture huge) where one of the 15's is the Beyma 15DX coaxial with a large format 4" diaphragm built in and an 18 in a sub horn below that. The bass keeps up fine however I have a dipole 3-way line array with twelve tens and the same horn sub and the bass system will not keep up with the large format horns (meaning my 2440 JBLs in 300 Hz round tractrix horns) - I've tried it and found 24 5.25 and 30 domes to be a much better match
If you want ease, tone and majesty with low compression and 'they are here dynamics' I recommend fully horn loaded. Be prepared for a long journey if you take that path though. They are very difficult to get right and when they are close you may wonder if it's just too much - meaning the sound can be so transparent you can hear a fly fart on the cello....... I gave up on it it sort of - a line array dipole can be close in dyanamics and not so finnicky or expensive - plus the sound is bigger as well as the sweet spot - line arrays really do drive the room better then something like this:
An externally hosted image should be here but it was not working when we last tested it.
Salas:
I agree most arrays I heard are of bad design and have built in low performance dispersion characteristics from the beginning but there are also examples of array deigns that mediates a stunning impression almost where ever they are placed….
Below in my opinion, is an example link to a bad idea, using the Visaton B200 in an 8-driver bipole array trying to cover the whole spectra...
My opinion is that this array should only be used at max to 700 Hz covering the upper bass - middle midrange and if 12 dB LP filters are used or when the upper midrange (< 1.3 kHz) must be included, at least 24 dB LP filters are necessary.
Se my polar plots that show the B200 behaviour below 1250 Hz is rather accurately described with point sources within about + - 15 degrees azimuth ignoring the real effects from the baffle width/depth/step/diffraction that have to be estimated separately.
b
1(6)
I agree most arrays I heard are of bad design and have built in low performance dispersion characteristics from the beginning but there are also examples of array deigns that mediates a stunning impression almost where ever they are placed….
Below in my opinion, is an example link to a bad idea, using the Visaton B200 in an 8-driver bipole array trying to cover the whole spectra...
My opinion is that this array should only be used at max to 700 Hz covering the upper bass - middle midrange and if 12 dB LP filters are used or when the upper midrange (< 1.3 kHz) must be included, at least 24 dB LP filters are necessary.
Se my polar plots that show the B200 behaviour below 1250 Hz is rather accurately described with point sources within about + - 15 degrees azimuth ignoring the real effects from the baffle width/depth/step/diffraction that have to be estimated separately.
b
1(6)
Attachments
mige0 said:
I agree, nice simulation - what software is this? What's a little confusing is I can't clearly see what the loudspeaker array pattern that's being simulated. Obviously, it is simulating different types of arrays - I just can't quite make out what it is.
Shifting over to the time domain, the arrivals at the listening position will be non-coincident, unless a sophisticated Quad-like delay scheme is used. This will cause ripples in time, frequency, and polar domains. If a dipole is used, we also get all the same information, but with an additional set of delays diffracting around from the rear. Many many reflections.
Not to let complex multiway systems off the hook - they get complicated at the crossover frequencies as well.