Rerurn to Romy the Cat's Site

Audio Discussions
Topic: Tha is all fine but...

Page 1 of 3 (43 items) 1 2 3 »


Posted by Paul S on 06-12-2023

The Loudspeaker (Troels Gravesen project); a report started "too soon" because they've taken sooo long to build, and they fired right up (first try), and they already do Music!
 
For some time (at least a decade) I thought about building a very large center speaker, in order to add power and Musical presence to my stereo system. I played with many vintage drivers, trying to improve the sound and increase the amount and range of Musical sounds I got from them. Fair to say, I learned a lot, including sobering up with regards to my own manufacturing capabilities. As it turns out, I just don’t have the chops to make my own drivers. During this time I listened to and kept track of many stock speakers and drivers that interested me, including re-built and classic-type direct, horn, and hybrid speakers. I ran across Troels Gravesen’s website a couple of years ago, and I liked the way he went about things and what he said about vintage drivers and open baffle speakers that I already knew something about. When Troels came up with The Loudspeaker, I was hypnotized, and I saved up and bought the Jantzen kit (which includes full specs), then I back-ordered the drivers from US-based pro sound distributors. I used Visaton horn UHF drivers. My hopes/expectations were fueled by “classic” JBL speakers I have heard over many years. Generally speaking, I was hoping to wind up with speakers that were very immediate and lifelike without being too shout-y or pushy. Due to the pandemic and personal health issues, it’s taken me a long time to finish this complex and difficult project. Anyone interested in what Troels has to say about it can go here:  http://www.troelsgravesen.dk/Diy_Loudspeaker_Projects.htm
 
Troels’ original The Loudspeaker is either based on or it’s coincidentally very similar to the fairly short-lived JBL 4345 studio playback monitor, a Greg Timbers design/model I’d heard about but never actually heard. For better or for worse, Troels’ version uses selected and mated modern/contemporary “pro” divers rather than re-built or new JBL “tribute” drivers, along with Troels’ proprietary crossovers and his own cabinet design, which is very similar to but not the same as the JBL 4345.
 
Please note: IMO, The Loudspeaker is not a good first (or second…) DIY project. It’s just too big, heavy (over 200#/ea.) and complicated for a rooky to handle. This was a very difficult project for me despite I am a Master Carpenter with over 50 years of experience and lots of tools. Basically, these cabinets are a job for a fully-equipped (and properly staffed) cabinet shop with full scale panel saws, etc. In fact, CNC would be nice! My approach was to “circumvent” the fixed equipment with very basic “work-arounds”, including dead flat cutting tables on the garage floor, a special blade for my Skilsaw, and several straight edges. I can’t in good conscience “recommend” any of my work-arounds; there’s just too much margin for error, especially given the cost of the Baltic Birch plywood, which is very “unforgiving” and difficult to process under the best conditions. Further, glue-up of sub and main assemblies also requires flat tables, and 3-D controls. There are lots of pieces, and assembly is very complicated and nearly impossible without a lot of pre-engineering and pre-fitting, and, preferably, another pair of experienced hands, not to mention loads of clamps and well-thought-out control measures to get and keep everything in line for clamping before the glue sets up. Regarding construction details, I will tell more on Troels’ Builder Response board only. Here at GSC I’ll try to stick to conceptual and construction basics and focus on the sound. I do want to want to mention that I spent a lot of extra time messing with glues and sound deadening/dampening ideas as I went along. Also, I bi-wired (and internally wired) my Loudspeakers with 12 gauge Speltz Anti-Cable speaker wire. One pair of speaker wires goes from the amp to the woofer X/O, and the second pair of wires goes from the amp to the X/Os for the rest of the drivers. I should also say that my X/Os are all passive, at speaker level. My amps are Marantz MA9-S2 monoblocks that are literally made for bi-wiring, and these amps put out a lot of power, including a whole lot of current. I have already posted plenty about these amps on this board, and they are an integral part of my speakers in my system.
 
Per Troels, The Loudspeaker is a 95 dB efficient, 4-way design that uses an 18” treated paper woofer in a big reflex cabinet from about 25 Hz up to ~160 Hz; a 10” paper cone midrange unit in a sealed box up to ~1,300 Hz; a compression driver and a short horn for upper-mids and treble to ~9k Hz; and I use a compression horn for UHF above 9k Hz, for anyone who can hear it.  Again, look at Troels’ site if you want full specs. Please understand that I am not offering any specs as “proof” of anything, in any case.  I will repeat, because I like this quote, what the original designer of the JBL 4350, Greg Timbers, said of that speaker, that “It does not know it is not supposed to sound as good as it does.” When it comes to designing a loudspeaker, I agree with Troels that any loudspeaker is a pile of compromises, so it’s basically a matter of Pick Your Poison.
Like I said, too soon to say much. So far, I've only listened to 3 LPs: Kind of Blue; Sketches of Spain; Solti/Chicago Symphony Orchestra, Bruckner 7. I actually built them to try to further explore Bruckner and other "difficult" Music, and indeed, new Musical doors are already opening.

Paul S

Posted by Romy the Cat on 06-13-2023

Paul, congratulations on your finished project. I do not have a lot of experience with central channel, I wonder how you route signal to it in context of stereo recordings. If you use DSP then I presume that it is more deterministic to the final result than the quality of your central channel speaker.  What I find interesting in your post is the following: “in order to add power and Musical presence to my stereo system…”  What do you mean? Why do you feel that your center channel helps you to add the “Musical presence”? Are you sure that it is “Musical presence” and not something else?

Posted by Paul S on 06-13-2023
OK, Romy, maybe more like, the presence of Music. I felt like I was getting good sound, but I wanted more of it, with "an expanding sense of it", including better "center fill". We have talked here about the technical/electrical problems inherent in re-allocating parts of left to right and center, and vice-versa, and I just could not convince myself to continue the center channel, not to mention the extra amp (which I actually kept on hand for several years...). I got resistant to "solving" the algorithm/allocation thing, and even James Bongiorno himself did not win me over, in the end. What I went for instead, and what it appears that I do have now, is just lots more power that "gets out into the room", to charge the room. The horn I have now is very short and "fast", more like a wave guide, and the sound does not attach to the speakers in my current set-up. I will try to do some pictures. If this does not work out, it won't be because I did not get what I wanted; it seems like I did get that, and at this point I look forward to continuing with it.

I checked again, and I first contacted Troels Gravesen about this project 4 years ago, and I started seriously rounding up parts 3 years ago!

Best regards,
Paul S

Posted by Romy the Cat on 06-14-2023
Paul, what I am saying has nothing to do with your Troels project but rather a psychological exercise to understand what truly is going on. Also, I very much not knocking at your door with my mental approach to audio objective am trying to demonstrate that everything is not so simple.
 
So, you are injecting int the room one more acoustic system that for sure “increase the density of Music” in your room. How can we methodologically differentiate from the changes you experience after you put your central channel in play and the changes you would experience if you increased the radiating surface of your right and left channel? It is not clear what kind signal you use to drive your central channel and not clear how your right and left channels are installed in the context of your listening room. So, from perspective of general audio analysis we still do not know if the improvements you might have related to the functionality of the “central channel” or related to the functionality of “another channel”. Here is a little methodological tip that I use myself to understand what is going on. When you make acoustic change like this, try to take your focus from what became better towards to observing what become worse. For whatever reason when this think about what become worse we are dealing with known N it multiple time help me to debug problem much more accurate.
 
Anyhow, if I were in your shoes I would experiment to drive the center channel from different type of signals, probably a good digital signal processor would help you with experiments To get out of main signal sum, delta, different phase shifts, and all of it might be very much frequency dependent. The digital companies did a tone of research in this direction. While you experiment with this do pay attention not only to what became but what became worse. Interestingly, I do not recommend to find error configuration when amount of worse is minimal and to use it. However, knowing in which configuration the damage from central channel is minimal will give to you a reference point upon which you can keep your mental aim.

Posted by Paul S on 06-14-2023
Romy, are you thinking I am running a center channel now? I am not. I am just running the new stereo speakers, right and left. I had already decided that I wasn't going for the center channel before I went this way, for all the reasons I cited. I made an announcement about it and sold my 3rd amp, maybe 3 years ago. The only way in which my current stereo set-up "derives" from thoughts about a center channel is the idea of putting substantially more energy into the room, especially in terms of "center fill", and I have done a version of this with more powerful stereo.

Best regards,
Paul S

Posted by N-set on 06-17-2023
Paul, congratulations! But which of Troels' projects have you completed? The webpage shows them all.

Posted by Paul S on 06-17-2023
Jarek, it's the biggest thing he's done, as far as I know, dubbed... "The Loudspeaker". Hence, the title for the thread... He went on to do successively smaller versions, the TLII and the TLIII.


http://www.troelsgravesen.dk/The-Loudspeaker.htm


Best regards,
Paul S

Posted by Paul S on 06-28-2023

Weird, I realize, but this speaker project included a mental exercise about “proper” playback for Bruckner 7”, how to facilitate hearing and figuring out what is going on with that Music. As ever, I turned different speaker and amp ideas around in my head like a Rubik’s Cube, trying to mentally line up a design with the sonic goals until they “clicked”. I have heard very little Bruckner played live, but brushes with Bruckner’s music, live or recorded, always piqued my interest, even as it confused me. My previous speakers are good enough that I have known for some time that Bruckner uses LF and dynamics “differently”, but I haven’t clearly heard, felt, or understood what he is doing before now. Very generally, I felt like I needed “more” of what I had, and it would be a plus if only the 2 speakers had to change. With these speakers (and the same MA-9S2 amps) I can finally hear and feel the incredibly rich LF sonorities that Bruckner creates. I also hear differently/better and understand better the slow to mid-tempo “crescendos” that eluded me before, now that the rising and falling is better articulated, resulting in certain rich textures that derive from amazing, subtle timbrel and dynamic instrumental contrasts, both assonant and dissonant, at times spread out over surprisingly long intervals, and at times very loud. I also enjoy the way Bruckner uses large ensembles in every register to weave tapestries of sound, including texture. The feeling I get is that Bruckner seems to be in grateful awe of Creation, and his Music makes me feel that way, too. Perhaps, once one hears and understands Bruckner this way, it is possible to hear and feel it from a car radio or a boom box. Anyway, I am just, finally, starting to get it, and it looks like I took a wild shot at this, and it’s working! In truth, when I read about these speakers, I equated them with big JBL monitors I’ve heard, and they “matched up” pretty well with my developing mental picture, which included most of my existing set-up, and I pulled the trigger. I referred several times to this project as my “latest folly”, because I was not 100% positive how this big, difficult, expensive project would work out. Heightening the tension, I built the whole project before I listened, over 3 years, and I basically feel like I lucked out. Others can decide if my 60 years interest in audio, including a fair amount of DIY, and tons of “mental cataloging”, gave me the background to steer myself where I needed to go to get what I wanted. I’ve made plenty of audio mistakes. I’m glad this was not one of them. I should also say that I remain a musical omnivore, and if I’ve lost anything by adopting these speakers, in gaining Bruckner, I have not noticed it yet. I feel like it was Troel’s design; I just curated, and I was lucky. It would be too funny if these speakers only did well with B7, but not other Bruckner!

TL1finishedfonnt.JPG  

>Sorry about image size! This is the first time I posted a picture here! It took me several tries. >

Paul S>>


Posted by Romy the Cat on 06-29-2023
It is a very interesting subject, Paul. If we presume that an acoustic system has an objective the most “interestingly” reproduce Bruckner, then what the acoustic system he should do? Pay attention I did not say more “accurate” or more “faithfully” as that is a whole different subject and the one that I do not particularly subscribe to. I do not wan to hijack you thread as I can write 1000000 wor0s about it but I think thinking about it for an audio person is very healthy.

Posted by Paul S on 06-29-2023
Romy, I actually feel a little sheepish that my process did not include a multi-media map for others to follow, if they choose to, although Troels already did a great job of exactly that. I did post construction pictures and explanations on Troels Gravesen's builder response board: 

http://www.troelsgravesen.dk/The-Loudspeaker-1_Paul_US.htm

This hyperlink is the place to look for construction details pics, although I will be happy to discuss here both the rote project and the Bruckner/Music connection.

Again, Romy, I did not mean to make the picture so large! Feel free to reduce the size of it!

Paul S


Posted by Paul S on 07-09-2023
Via Mengelberg’s performance of Ein deutsches Requiem, Philips CD
 
Perhaps it’s possible for someone to “get” Brahms’ Ein deutsches Requiem by way of a table radio. Speaking for myself, I only got hints that way, and it wasn’t until I took special steps with my sound system that I began to understand this mighty work. Naturally, I had to try this CD with my new The Loudspeakers! And despite the CD itself was damaged a while back by playing it in my old Volvo, I was immediately drawn into the piece and I had a better experience with it than ever before. Make no mistake, the re-recording of the 1940 live performance is not “audiophile quality” to begin with, and The Loudspeakers are not good because they “fix” that problem, but they are good because they bring me more than before from both the Music and the performances, despite the compromised aspects of the recording. I can’t say there is more color from The Loudspeakers than from my BassZillas, but there is certainly more coherent LF information. In fact, there is more coherent information at all frequencies, and the sound spectrum is better sorted out, overall, as well, I think, generally less tipped up. Massed violins are better pitched, and more natural for that, and they are clearer vs. recording artifacts; and the same with chorale voices. Basically, I get More Music from this CD, and this has been the case with several “compromised” recordings I’ve listened to, so far. I am still working to get my vinyl playback where it was before I pretty much went off the rails, a couple of years ago, but even now I get Music that can be better than the sound of the LP itself would suggest to an audiophile. I am always happy to add program, and so far The Loudspeakers are helping me to do this. 
 
Paul S

Posted by Paul S on 08-08-2023

Like I said in my previous post, I lost my tonearm/cartridge synergy a while back, and then I realized that I needed to replace the surrounds on the drivers in my BassZillas, and I shut the system down for some time, until I got The Loudspeakers up and running. So, I’m glad to say, it’s been pretty easy to tell what’s going on with the system via The Loudspeakers, as they break in, and I as blow the cobwebs out of my long-idle electronics. Today was especially nice, starting with some Coltrane, then on to the Scherzo and the Finale from Bruckner 7. Great listening to both LPs, and I still feel expansive enough at this point to say these speakers were “worth it” just for the Bruckner 7! By the end of that LP I was weeping with joy! This Music is magnificent! I really look forward to “getting into Bruckner”. I just now found a few more Bruckner LPs I was afraid I’d just imagined. I guess I’d “set them aside”, then forgotten about them, because they were not where they were supposed to be, in my record racks, where I expected to find them (but couldn’t) last week. I plan to get Wand’s Bruckner 8 that was recorded live in Lubeck. I’ve only seen this performance on CD, so I guess that’s peripheral to this post. As for how, specifically, The Loudspeakers have revealed Bruckner to me, it turns out I got the “more” I wanted. There’s just more Music there now than there was before, and The Loudspeakers do more Music with less fuss and bother; they make it seem natural, and “easy” in that sense. I’m still messing with speaker positioning, pretty much gilding the lily.

Paul S


Posted by Romy the Cat on 08-09-2023
Paul, you are lucky person, I never was able to find Bruckner music on LP that I felt was good quality sonically and artistically. I own a lot of Brucker LPs but I hardly ever listen them.

Posted by Paul S on 08-09-2023
Well, Romy, at this point I am listening more to the Music than to the performances, if you know what I mean. I already shared the Solti/CSO 7th LP, an old London ffrr stereo that does not seem to have the weird curve. So far, that’s the beginning and the end of my good luck with Bruckner LPs. I hope but do not expect to be so lucky with the other LPs I just “found again”. After all, there were reasons that I haven’t played them for years. It remains to be heard whether I can glean significant Music from these LPs.
 
Paul S

Posted by Paul S on 08-13-2023
Like I’ve said, my aim was to find/build a pair of speakers that could be driven “full range” by one of my Marantz MA-9S2 amps per stereo channel, and these speakers would have to give me greater insight into Bruckner in order to fill the bill. I put “full range” in quotes because, now that I have stronger, deeper LF I can hear “what it would be like” to have ULF. And so it goes. Does this mean there is a problem with TL bass? Perhaps the apt analogy is adding a helicopter deck to one’s luxury yacht. After all… 
 
Meanwhile, it seems like these “95 dB” speakers play louder at the same volume settings than my “97 dB” Basszillas. Not that this is the first time in my audio experience I’ve noticed this sort of discrepancy. One case in point is my Visaton TL 16 H (horn) super tweeters, which definitely play louder than my Audaphon UHF ribbons, at least they contribute more at higher volumes. And I think this is part of the phenomenon, that the lighter-weight, “more efficient” drivers choke up when the going gets tough. I have to say, the TL drivers have sounded better and better as I’ve played them more and more, not in the sense of some “ever-present” quality or qualities, rather they do a better and better job with “soundstage” and rendering dynamic and tonal differences. If I was happy before, I am becoming fairly content with these speakers. I suppose it’s in my nature to push my sound system occasionally, just to do it. A nice 10 - 12” vintage driver powered by a small SET can produce some intoxicating music. But it does not make Bruckner happen for me. The Loudspeakers and my amps do make Bruckner happen for me, and the combination makes Casals or Manitas de Plata sound pretty good, too; in other words, they seem to “scale” well.


Paul S

Posted by Paul S on 08-16-2023
Something worth thinking about as one chases an “ultimate sound system” is that “accurate” playback will likely reveal sounds of the recording process along with the musical performance. And The Loudspeakers are certainly “guilty” of this. From knobs being twiddled, to reverb, mixes, and artifacts from previous iterations, the playback through The Loudspeakers will be a close repetition of the signals they are fed, for better or for worse. Speaking for myself, I would rather do without the sounds of the engineering. However, these sounds have so far been a consequence of insisting on “faithful reproduction” of recordings that has otherwise paid off in terms of Music appreciation. I am certainly open to getting the upside I get via The Loudspeakers without the baggage, if anyone wants to share how that’s done. But to date I have not heard “the good without the bad”, as it were, on this score, although some recordings are better than others, for sure, in any number of ways.  As I have noted, The Loudspeakers do not emphasize non-musical or a-musical parts of recordings. In fact, they seem to do a pretty good job of “sorting out” and “setting aside” parts other than Music.  So far, this has been better than worse, and I continue to work to take advantage and make the most of good engineering and poor engineering.
 
Paul S

Posted by Paul S on 08-23-2023
A while back I mentioned that I would not want speakers that could not “do” Gieseking. Well, The Loudspeakers do Gieseking, all right, including telling me more about his performances of Debussy’s Etudes. I have long admired and appreciated Gieseking’s wide range of expression over a relatively narrow dynamic range. Via The Loudspeakers I can now hear and feel his physical strength, and just how hard he can push the keys down with no “wind up”, and it is clear now that his overall dynamic range is a good deal wider than I’d thought. I had also thought that his use of the pedals was very limited. But now I can hear that I was quite wrong about this, as he uses the pedals extensively, he is simply deft at this, as he is with the tinkling chromatics that light up this Music. He also feels less aloof via The Loudspeakers; I can feel his vulnerability as he performs. This from a brittle old Angel LP that most audiophiles would pass on, I’m sure, not to mention this Music sounds like gibberish through most systems, to begin with.
 
Paul S

Posted by Paul S on 09-03-2023

Something about The Loudspeakers that shoppers have likely noticed is that the original design electrically splits the 18” woofer from the MF, HF and UHF drivers.  And, just to be clear, there is sound thinking based on lots of experience behind this design. It takes lots of power to get deep, Musical bass at concert levels from a loudspeaker, and if there is a work-around here, I have not heard it yet. To be clear, I am not talking about sound effects or Mobile Sound Club systems, but I am talking about serious Music via home systems. Troels saw/heard the wisdom of Hypex for LF, to allow for better sounding amps for the other drivers. And anyone who goes another direction (as I have done) will want to think it through carefully (as I have done) before committing funds and effort. I am still playing with my Loudspeakers, but another thing worth thinking about is that a woofer that does 200 Hz Musically won’t be doing Musical 18Hz at the same time. Based on things I read, it looks like plenty of vocal audio people think “good bass” means prominent bass, just like “good HF” means lots of details and “air”. I think I will not get on my soapbox but I will answer questions about this if/as they come up. Meanwhile, 18” woofer notwithstanding. The Loudspeakers have nothing to do with prominent bass or sound effects but everything to do with the unaffected revelation of the Music that’s in the recording, at least this is true of my version. I will say I would not be happy if I found myself mentally parsing the Music as I listened to it. I am OK with the compromises embodied in The Loudspeakers (my version, anyway) because they have a very broad range of Musical expression that allows me full access to my Music Library.>>


Paul S


Posted by Paul S on 09-13-2023

I’m thinking I’ve never mentioned on this board that the listening room I’ve used for the past 16 years is 21’ X 17 ½’ X  8’. It has three large openings into a very large house, including a long, wide hallway and successive open rooms. This means The Loudspeakers have a big job to do in order to charge this room. My strategy so far has been plenty of amplifier power, and sitting close to the speakers, which I have well out in the room, over 7’ from the front wall. The sound I am after at this time is the sound that charges the room and “appears” spread out behind the front wall, loading into the room from there. There is little to nothing in the way of standing waves, and I am amazed to get plenty of HF from my horns with the speakers slightly toed out. Orchestras can be very powerful, depending on how they are mic’d, and well recorded solos and ensembles sound and feel like that, according to the production. As far as the drivers go, these are not high directivity, quite the contrary, so they lose those benefits but gain in terms of room loading. Between the 18” and the 10” direct drivers and the M/HF compression driver with its very short, fast horn, these speakers really do seem to charge the air, itself at all frequencies. I am surprised and pleased that the Visaton UHF horn also, somehow, gets its contribution into the mix off axis. I will say, as I have opined before, that there is such a thing as too big for a listening room, and I feel like I am right at the limits of what I can use with these speakers and my present amps. While there seems to be plenty of electrical and mechanical power for more volume, I think I would have to do something to contain the sound to keep the air charged if this room were any bigger. I would also say that a smaller room would be fine with these speakers, and one might then use smaller amps for MF and HF, although I stick to my previous observations regarding LF and amp power: Even in a smaller room it takes big drivers and big power to get orchestral LF.>>


Paul S


Posted by Paul S on 09-23-2023

Today was a good day in The Loudspeaker Land. I’ve been using The Loudspeakers to do some targeted listening, with excellent results. I already mentioned at the start of this thread that I had lost my cartridge/tonearm synergy a while ago, and today I got it back. From there I used better Sound to dial up the MOSFETs in my phono stage, also with great results, including more depth and vertical ambience, and I’ve re-positioned the speakers closer to the front wall, resulting in greater room charging.. I think (hope) all this will keep me pie-eyed and not thinking about Reverb Injection for a while.>>


Paul S


Page 1 of 3 (43 items) 1 2 3 »