This was more than a decade ago. I detected the change, but B&C would not disclose what it was.
In my 2-way speaker with passive xover, I had the issue you describe as well. A big part of the problem for me was the interaction of a lossy LF inductor with low power tube or Pass Jfet amps both of which have low-ish damping factor. The right 15 inch driver to use are rare but they exist, so I think problem is 95% solvable and I did solve it. IMO Introducing a midrange and sub creates even bigger problems but let me know what you figure out.
Primary Control turntable and PhaseMation preamps amp/cartridges are the only analog setup I'd purchase at this point.😍
Sorry but it's your fault for reminding me of that beautiful analog sound and mentioning Magico and CHprecision on a DiyAudio site 😆😉
Thanks for the reply. Which 15" driver did you end up using? And what are the issues in your experience of adding a midrange and sub? And what sort of crossover frequencies pose issues if implementing the type of three way which you have in mind.
No doubt about the ridiculous of Magico and CHPrecision. I know very little about either brand's products to be honest aside from seeing some impressive looking cross sections of Magico's and also it seems their premium drivers are pretty cutting edge. I have listened to a pair or two in the past also though do not remember them being as impressive as the M6's which I heard yesterday. The whole system was very dialed. I am a less is more kind of guy and the size alone of those CHPrecision amps seems utterly idiotic. The system sounded good though...
No doubt about the ridiculous of Magico and CHPrecision. I know very little about either brand's products to be honest aside from seeing some impressive looking cross sections of Magico's and also it seems their premium drivers are pretty cutting edge. I have listened to a pair or two in the past also though do not remember them being as impressive as the M6's which I heard yesterday. The whole system was very dialed. I am a less is more kind of guy and the size alone of those CHPrecision amps seems utterly idiotic. The system sounded good though...
TAD 1601a
I use LF/HF 900Hz cutoff and a 500Hz horn fills the gap nicely. I find the low Fc horn is necessary to sound complete. Importantly, going to 8ga for the LF series inductor makes a BIG difference in information content and detail coming out of the driver.
AFA the midrange, I tried a few things but I never liked it, for me is a question of integration. With midrange cone I always hear the driver. The sub makes it even worse. Maybe it would be different with a midbass horn but I have no room for them. I think 2-way is the best I can do.
Don't get me started on CH precision and the cult-like customer base which should be the subject of doctoral dissertations. 🙄
In Munich last year I sat through a whole demo of the effects of improving some whatever technology they had going on in their digital chain. Of course any change was increasing the system ticket by $10k's. One change I did hear, the rest sounded all the same to me. Meanwhile as everyone was focused on the trees, the forest was ignored: the system sounded flat, overly analytical and absolutely 'a-musical', If there is such a word. 😉🤔
I use LF/HF 900Hz cutoff and a 500Hz horn fills the gap nicely. I find the low Fc horn is necessary to sound complete. Importantly, going to 8ga for the LF series inductor makes a BIG difference in information content and detail coming out of the driver.
AFA the midrange, I tried a few things but I never liked it, for me is a question of integration. With midrange cone I always hear the driver. The sub makes it even worse. Maybe it would be different with a midbass horn but I have no room for them. I think 2-way is the best I can do.
Don't get me started on CH precision and the cult-like customer base which should be the subject of doctoral dissertations. 🙄
In Munich last year I sat through a whole demo of the effects of improving some whatever technology they had going on in their digital chain. Of course any change was increasing the system ticket by $10k's. One change I did hear, the rest sounded all the same to me. Meanwhile as everyone was focused on the trees, the forest was ignored: the system sounded flat, overly analytical and absolutely 'a-musical', If there is such a word. 😉🤔
I would imagine those TADs sound nice. I have a pair of Altec 515 woofers on hand which I have not tested yet, though I think they are an older iteration of a similar design principle -- low mass high efficiency driver. That said I also think the 15G40s which I am using are of a similar nature and at a 700hz crossover the results aren't satisfactory. I am using active crossovers so the circumstance you mention about lossy inductors impacting frequency performance is not identical to my situation. Have you considered using an active crossover and two amps per channel?
I couldn't find the TS parameters on the 515 but if the highly compliant surround and 25Hz fs are any indication these will need 300L cabinet with a hole in it, like my 416. The LF should be quite good.
I have little experience with active systems, everything I tried was always opamp, very basic and poor sounding. I know Nelson designed a state of the art xover. I should probably try that.
I have little experience with active systems, everything I tried was always opamp, very basic and poor sounding. I know Nelson designed a state of the art xover. I should probably try that.
You mention CH Precision being a cult of sorts. I can see that though I lets not forget that one could say the same about DIYAudio and particularly many peoples' allegiance to Nelson Pass. I like his open source and diy friendly methodology a lot more than the high end snake oil approach. And his design ideas are interesting for their time though I feel there are more advanced contemporary options, whether from Hypex, various very low distortion class AB amps available now, etc. I have heard an XA25 which sounded lush and nice. I am curious about Firstwatt Class A amps though the non diy versions seem pretty over priced. And it seems some of his offerings measure quite poorly. He's no dummy though to my knowledge a Topping PA5 measures better than any of his designs. I admit, though I probably shouldn't be, I remain curious to try some of his amps or other solid state class a amps even though science tells me not to. Wishful thinking or something I guess.
Hi guys,
We talk a lot bout CD here but what woofer do you use for 2 ways?
I'm using TAD CD so I use 1601b. I was wondering what other good woofer to pair out there.
Thanks
We talk a lot bout CD here but what woofer do you use for 2 ways?
I'm using TAD CD so I use 1601b. I was wondering what other good woofer to pair out there.
Thanks
When you start talking about $100k amps you need to get into justifying the expense. That's when people start to do snake oil shots.😵
Pass amps sound as you describe: lush and nice, 'California nice', from the era when JBL and Altec were based in Cali. 😉
IMO low power Pass amps are ideal for horns, a point I did not appreciate until recently. I am interested to try a tube amp and an hypex nilai in my horn speakers. I need to get out of my comfort zone and see what's up. What amps are you using?
AFA opamps I have have very mixed luck with them, even very recently. I have done a bit of opamp rolling in my time and the results can be diametrically opposed.
I think you can stop! Your search in the 15in cones is over, you are already using the best.😉 I suppose if you rearranged the midrange horn, you could go 18inch for the LF, in which case there is quite an unexplored world of high Vas low Fs drivers that I have not investigated.
I am using a stereo Boxem Arthur 4215/E2 amplifier for the 15 inch woofers which is designed around Purifi 1ET400A Class D amplifiers. And a Topping LA90 Class AB amp for the horn compression drivers. I tested several amplifiers against both including a premium 211 tube amp. The LA90 is noticeably more resolving than the others which I tested. Compared with the Class D Topping PA5 which I also have, it is more musical and pleasant in my opinion. I do think Class A and Class AB amps can be advantageous over Class D amps depending on the implementation. I remain very attracted to simple Class A tube and solid state circuits.
I now mostly use the Pass Vfet follower from the diyaudio lottery. I think it complements the TD-2002 amazingly. It also sweetens old, and poorly recorded materials from the 60s and 70s. Makes the sound very 'period accurate' and high definition at the same time. If that makes any sense. 🙂
I will investigate your amp choices.
The new Hypex amps are high on my list of things to try.
I will investigate your amp choices.
The new Hypex amps are high on my list of things to try.
The amps I am using aren't as powerful as the Nilai but measure the same or better. Bruno Putzeys who designed the original NCore amps and started all that business, also designed the amps which I am using.
Back form vacation.
I use the 15 inch 2226 as a woofer and the 10" JBL 2123 is a mid-range. The crossover is at 400Hz.
Thanks DT
Just for reference, I am running Pi7 Corner horns with JBL 2226 on the bottom, JBL 2012h mid and RADIAN 450BePB on top.
The drivers seem like a good combination.. The 2012h are hens teeth.
The drivers seem like a good combination.. The 2012h are hens teeth.
More of an odd duck.
Look at an impedance plot. From 300Hz to 3.5 Hz the plot is flat, as in the Inductance is near zero due to motor copper pole plates. The thing is a beast, it is 20 pounds.
Another odd thing is the rising frequency response amplitude.
See the attached impedance plots with and without an added~1.0mH inductor.
Thanks DT
I will put the JBL2012 driver in a box and measure the FR with and without the added inductor. My guess is that the inductor will flatten the rising frequency response.
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Well a bit of confusion is here. The person that is more or less connected with all these products is James B. Martini (Lansing).
The first compression driver in the Altec Lansing 288 family is the Lansing 284. Designed by John Blackburn and assisted by Lansing, it is a field coil compression driver made with an annular slit phase plug, an aluminium annular compliance diaphragm with screw binding posts. The 285 was a variation that have a radial slit phase plug designed by Blackburn to address patent issue. The 287 was a version that use bolts and a gasket to be fixing to the throat of the horn instead of being screwed.
The original 288 (A or Hollywood), improved by Lansing, incorpored a permanent Alnico V magnet and an easier to replace tangential diaphragm. The 288B has minor modifications made to the diaphragm mounting. The 288C is supposed to have improved high frequency performance, but the I cannot find the technical difference with the B version. The D and E are 16 and 8 ohms versions of the C (24 ohms). The 288G incoporated a heavier Alnico V magnet, a higher flux density (+11%) than pervious 288 version and spring type connector. The 288H incorporated the tangerine radial slit phase plug. The 288K change the magnet form Alnico V to Ferrite. The 288L change the spring connector to electrical quick connect binding post. Since some audiophile found difference between diaphragm, phase plug, Field coil vs magnet, magnet flux density and magnet materials and that Altec claimed improved performance with each version, it it likely that compression drivers in the 288 line will not perform the same.
Has for the Bart Locanti connection, he designed the JBL 375, which is an modified version of the Western Electro 594, a field coil compression driver design by E.C. Wente. Locanti subsequently quit JBL for Pionneers in the 70's and was involved in the design of their speakers, included the Technical audio device brand of professional drivers. Here is their timeline.
All those drivers are refinements or variation of the first compression driver, the Western Electric 555W. To this day, this compression driver give an impressive performance considering that it was designed nearly 100 years ago.
A most insightful description - thanks.
Am I correct in understanding that Altec-Lansing started as The All Technical Group - Lansing (for location)?
Am I correct in understanding that Altec-Lansing started as The All Technical Group - Lansing (for location)?
