Thanks Tom. Yes, I was thinking to use 2 sealed subs with the 3.5.
13,744 responses Add your response
Just a thought. I suggest running the 3.5s wide open with no EQ. I remember the bass loading as critically damped, so it should approximate 12dB / octave. (But that's old memory) If you can match that rollout with a sub, the sub HF will operate in the directionality range, so 2 subs is better than 1. I for one am most in your progress. |
I'm exploring adding woofers to my system. I have a large listening space, 30x30x20 ft where I have my 3.7 positioned. Have the svs sb12 and pb12 on trial. Have a second listening space of 22x16x12 where I have my 3.5. Tell me about your experience, placement, cut off setting and anything else. Thanks |
An upgraded mic for an iPad is easy to use (and not expensive). I do it all the time with REW -
https://www.parts-express.com/dayton-audio-imm-6-calibrated-measurement-microphone-for-tablets-iphone-ipad-and-android--390-810 I also have a USB mic ( https://www.parts-express.com/dayton-audio-umm-6-usb-measurement-microphone--390-808) that I'll use with a PC. |
@last_lemming My suggestion to use an iPad was not good in your case. The iPad mic is good from about 200-3k cycles but really drops off below 200, coinciding with your problem area. A better mic is called for if you want to measure in the region you think is amiss. It worked fine in my case because I only needed to detect relative, not absolute, differences. |
tomthiel, Very interesting comments! Thanks for taking the time to explain some of the issues involved with the structures in front of the 2.2 tweeters. I didn't even notice that the center plate was actually a hex shape until you mentioned it. I'm fascinated by your work on the sharp edges on the back of the structure, and I hope your mods will have sonic benefits. I think I will hold off on attempting to epoxy the detached legs/prongs until you figure out what sort of contouring or edge-coating may be helpful on the structure. I also want to consult Rob before I do anything. Thanks again for the great info! |
Sdl4 - this is the first time I've heard of one leg being disconnected. They all three should hold the center plug in place. If those tweeters were mine, I would repair them with aluminum filled epoxy. You might consult Rob before doing anything and see what he thinks. That fore-structure performs multiple functions. It protects the fragile dome. It also spreads the on-axis energy for broader dispersion at the high end. It also acts something like a phase plug in that it retards the leading energy at the apex of the dome to average it with the circumferential energy closer to the surround. The hex shape of the center plate is engineered as superior to a round one. Considerable effort went into developing that structure, so I find it interesting when various pundits recommend removing it. I suggest trusting Jim's work, those kinds of details represent the meticulous care he took in the design process. What I am looking at is the sharp edges on the back side of the structure, both the 3 arms and the plug. We didn't address that level of detail in the 80s, but I wish we had, and I now am attending to unfinished business. I do not yet have confirming measurements (working on it), but I (believe that I) can hear improvement via contouring the edges of all members and coating with soft agents. Work in process. |
tomthiel, Your mention of your work on modifications on the faceplate surface for the CS 2.2 tweeter reminded me that the tweeters on my 1992 2.2 speakers have an anomaly that I've always wondered about. Many years ago, I noticed that the black metal frame protecting the face of the tweeter has a small gap where the top prong (of the 3 prongs) looks like it should attach to the round center piece of the structure. The tweeters are identical on both of my speakers, with only the top prong not connected to the center disc. The tweeters themselves have no dents or creases and they seem to work well. What is the purpose of the black metal frame in front of the tweeters (protection, waveguide, something else?) and are all 3 prongs supposed to attach firmly to the center disc? I obviously haven't been too concerned about this issue since I've ignored it for years, but your explorations into reflections off the surface of the speaker got me thinking about other issues that might affect tweeter performance/vibration in some way. Thanks for any insights you can provide. |
Andy2, glad to see that more people are getting familiar with options to have linear phase. The steepness of the slope had an impact on the pre ringing, as has the frequency of the filter.Although I've always believed in first order filters, I was somewhat skeptical of the "time-phase coherence" part and was not sure if it does make a difference. After converting two of my speakers xovers and making them "time-phase coherence", I am starting to become a firm believer in the advantage of "coherence". I am not sure what my mind is saying, but my ears definitely are hearing a difference. There is something in the sound that just more "natural". I guess that's the best adjective I could use. I would hesitate to use the word "better" though because people will have their own "belief", but I am comfortable with the word "natural". In my previous speaker design, although they also sound "natural", with "time-phase coherence", there is an extra "ease" as if the music "flows" better. Since I work on my own speakers, I was able to compare two identical speakers (same cabinets, same drivers ...), one with and one is without "coherence", and I prefer the "coherence" version. |
Gs I owned a pair of 3.6s that I purchased new in dec 92 I loved them!! last month I bought a pair of cs 7s (not the 7.2s) all I can tell you is if you can get a pair you won't be disappointed!!! They are like the 3.6s but even better more detail more bass I hear things I never heard Before!!! They do exploit my equipment upfront!! Just a thought FWI |
GS - you might call Rob Gillum at Coherent Source Service about this matter. Tinsel leads do eventually fatigue, and Rob has replacement moving systems on hand. The little I know about ferrofluid is that there are many types and quantity is critical. I don't see advantage to preemptive repair. I'm still using mine from
1989 CS2.2 prototypes with thousands of hours on their odometer. Let us know what you might find out from Rob about FF replacement and other issues. I am presently working on that tweeter via faceplate surface and diffuser modifications. That tweeter was Thiel's first ground-up design which was for the 1988 CS5 (with trickle-down to 2.2 and 3.6). |
I have a pair of 3.6's that are now 25 years old (nothing I heard in all this time makes me want to retire them) and I am concerned about old age issues. Have any of you had problems with the drivers? I am wondering if it is a good idea to take apart the tweeters and clean out and replace the ferrofluid. Or better yet, does anyone sell the rebuild guts? Thanks |
@last_lemming Do you have a way to measure SPLs, confirm your subjective impression? When I rebuilt my CS2.4 crossovers, I was able to compare the before and after frequency response using the SafeNoise app on my iPad and a tone glide. BTW, not that I think this is your issue but have your tried a set-up with the speakers on the shorter wall? Either way, I suggest taking a look at the Cardas website for some placement ideas to try after you figure out your problem. |
Andy2, glad to see that more people are getting familiar with options to have linear phase. The steepness of the slope had an impact on the pre ringing, as has the frequency of the filter. As the goal is to keep the pre ringing inaudible, lower order XO are better, especially for the bass to mid XO. For the mid to tweet xo, the frequency range of the drivers and distortion may determine the preference for the XO order. As the timing can be measured and adjusted for each driver separately, the time coherence can be obtained at the listeners position easily. |
@jazzman7, these just showed up in the last day or two. These same goofballs are offering a pair of Vienna Acoustics Mozarts for 4498. I bought a pair of Mozart grands for <500 when Best Buy dropped the line a while back. I realized how ridiculous the VA's were when I bought some Thiel 2 2s. They're very mediocre. |
Concerning Audio Consultants: I was just there on Friday. There is not much left, and what is left can now be had for 35% off. I don’t recall seeing a pair of 2.4s when last there, and I don’t think they have been bothering to keep the used list up to date, but if interested in something, it certainly wouldn’t hurt to give them a call. I also saw a number of demo items that are definitely not on the list. |
pair of 2.4s at audio consultants until they close forever on 12/21. They're listed at 1700 but I think the extra 25% off on the front page puts them at $1,275. An obscene deal for what you're getting. Makes me wish I needed more speakers. http://audioconsultants.com/UsedEquipment.aspx |
By the way, has anyone had a chance to listen to the "B&O" MS150? https://www.beoworld.org/prod_details.asp?pid=868 It is a time-coherent design, or at least that is the claim made by B&O. I think B&O uses the term "Uni Phase" design, or basically it means to have zero phase shift and able to perform a proper step response, just like Thiel speakers. But instead of using first order filter as the Thiel’s, it uses LR2, or second order filters. |
After been doing a bit research into "DSP option", it just happens that I may have found a mis-understanding, or may have been a false claim, with respect to time-coherent design. I certain did make that myself in this thread. Apparently, I myself did say a few times in this thread that "time-coherent" design is only possible with first order filter. But after doing some research into "DSP", it seems that a time-coherent design is possible for filter different type of filter, with different order such as 2nd, 3rd, or 4th and so on, NOT JUST with first order. Now it's also a matter of definition as well. If you want the strictest definition as possible, that is the only speaker that is qualified for "time-coherent" is first order filter then I guess there is nothing I can do about it, then if that is the definition, then only and only first order filter speaker can be called "time-coherent". But my definition of "time-coherent" is a bit broader. That is any speaker that have 0 phase shift and can perform a proper step response is qualified for "time-coherent" or "time-coincident". If this is the case, then there are other classes of filter designs that are qualified as "time-coherent". One example is "Bang and Olufsen" design, which uses LR2 (second order), that can perform a proper step response and has zero phase shift. Here is a picture of it: https://www.beoworld.org/prod_details.asp?pid=868 Not only that, but if you employ "DSP", then you can actually have higher order filter, which normally won't be able to achieve a proper step response, but you can introduce a "correction" factor in "DSP", that will make the overall speaker response to have 0 phase shift, proper step response and all. So now you can see that you have a situation where you have different types of speaker with different types of filtering topologies, 1st, 2nd, 3rd, 4th and so on, but all will have zero phase shift, proper step response, and and hence can be qualified as "time-coherent", which definitely will make things a bit complicated. So the question to ask is: is there any advantage of using "first order filter" at all? Because we have seen that any filter order will be qualified for "time-coherent" and able to perform a proper step response. Also another question to ask is: Are all "time-coherent" created equal? Is one better than another? |
last_lemming Nice! system. Interesting combination of Cardas/PAD cabling. Agree with Tom's assessment and suggested testing polarity. Does the B.A.T. pre-amp reverse polarity? The CS 2.4 loudspeaker is balanced Bass to Treble, Treble to Bass without any mid-bass fall out. Hope the culprit is diagnosed soon. Good to see you again. Happy Listening! |
Nice room dimensions. Don't switch anything until you know if there is a polarity problem.Disconnect the cables at the power amp. Connect 6V battery - minus to black wire and touch + plus to red wire. The coax and woofer should both move out. Repeat on other speaker. Your symptoms could be created by 1 woofer being polarity reversed. |
My ceiling is 10’ high. All speakers are working. As for the battery test I’m a little unclear as to your directions i could reverse one speaker connections to see if the bass improves, but assuming for the moment the highs are wired correctly and the bass was wired backwards my highs will end up out of phase, correct? i would need to flip the bass driver wiring I suppose. |
Hey guys. I’ve been struggling with getting decent lower mids and mid bass with my 2.4s. It always seems tilted towards the highs, as if the bass control was set to -6 dbs. They are in a 16 x 21 room on the long wall about 3’ off the front wall to the back of the speakers. The pertinent gear is below, source doesn’t sway the general tilt of the sound, nor does the quality of the recording, but it can make it worse. Equipment: Thiel CS2.4’s PAD Venustas rev. Speaker cable Parasound A21 amp BAT VK3ix Preamp (I’ve rolled many tubes) also has Six-Pack upgrade Cardas Clear light interconnects XLR REL 328 sub (for the lower bass) Technics 1200GR Turntable Glanz MFG 61 cart Audio Research PH3se phono preamp PAD Venustas phono cable not sure how to get the bass to be more balanced with highs it might be I’m in a bit of a bass suck out where I sit, but that doesn’t really explain the mid range not being as pronounced as it should. Thoughts? |
FYI. I saw a pair of CS3.6 for sale here at Audiogon from tmraudio which I bought a few stuffs from them and they have been very good. https://www.audiogon.com/listings/lis9hi9i-thiel-cs3-6-floorstanding-speakers-amberwood-pair-cs-3-6-20971-full-range |
Hi All, Well the last few comments have gotten me to thinking... Is my PrimaLuna Dialogue Premium inherently noisier than my CJ LS2? Or is it the difference in tubes types (6922's versus 12AU7's)? Or is it tubes that are wearing out versus new tubes? I have some thread reading homework and tube swapping to complete to start answering these questions. And my wife wonders what I do when she is out of town... Thanks for listening, Dsper |