I would like to share some ides what I would like to do in my monitor project.  This are just intention and I did not try to put it all together. Probably I will do it with the next few weeks.

I’m planning to use the Celestion SL-600 enclosure as I fill it is quite wonderful. As the MF driver I’m planning to use the source of my constant pain and pretty much what made met o think that it would be worth to try. In the end of the 90 I bought a Focal Utopia 165W set for my car. I had a hybrid tube-bipolar amp in my car that was driving the Utopia 165W (no subwoofers or any crap like this). Also I was very lucky to have a very good installer who did very good (and very expansive) job to mount the MF driver into my car. I was running that car off 3 year of the lease period and I can tell you that it was absolutely amassing sound.  The Focal tweeter are garbage and the sound like it but what the Focal Utopia 165W did in lower midrange kept surprised me and gave me a lot of very pleasant time.

The Focal Utopia 165W used 6.5” driver, It is typical W-type cone mid-woofer, with Neodymium magnet,
1.5 coil of 0.42mH, Fs=64.4 Hz, phase plug, 4" magnet, 93db sensitivity, meant to use with 24dB/octave at 2.5kHz. (It is not the today's "Be" version but the older one) I think the JM Lab use the same driver in their Mini Utopia monitor but I’m not sure. The Mini Utopia sound like crap and generally I’m not a big fan of the JM Lab multi-layers fiberglass coupled with the layers plastic foam. However, the Utopia 165W’s bass driver sounded nothing like Mini Utopia’s bass drivers. I presume that the similar larger drivers have that plastic, overly high resolution, depersonalizing tone but the smaller drivers might have no enough length of the cone to develop those qualities. Anyhow, the165W’ bass driver was very fast, very dynamic, phenomenal tonally, with superb withholding of tone and contrast at the lower listening levels (very big deal) and frankly speaking it was “a big secret of mine” how a pathetic car audio could be so musical. Of course a car is very small place and I would very much would like to see hot the 165W’s bass driver would perform in a larges listening room.

I’m planning to use it at 3.3kHz first order and high pass it with active basing first order at 60Hz. If it goes well then I will looks to the tweeter that would be relatively simple task.

The caT

cv wrote:

I note you calimed a fondness for certain softdomes; looks like there are some newer scanspeaks that may have the tonal qualities of your favoured types but with higher sensitivity, which will match the Focal well. Eg: D2904 types at http://www.madisound.com/cgi-bin/index.cgi?exact_match=yes&product=SST&cart_id=7087214.17882 Also have very low 520Hz resonance so would suit a first order cross... Btw, do you have a link for this Alian driver you mentioned. Pure curiosity...

I usually connect them together give them frequency centered pink noise around the crossover point, EQ the volumes and move my head at 3 feet from the axis of one driver to the axis of other driver. The driver should have different harmonic stricture but the same tone, same compression level, same distortion pattern, do “it” at the different volume levels (very important), have the same transient characteristics and so on. The point is the moving a complex signal within 2 octaves across the crossover point, and at the different volume levels Sound should not change lot…. The problem is that you need to have the damn driver in your hand, try it BEFORE you pay for it. That tricky… BTW, the D2905 Revelators drivers look very nice as well

Here is the link to the bass driver I told you. It is not available by browsing and possible only as the direct link. I have no idea why it is so.

 http://www.e-speakers.com/products/alian.htm

Rgs,
The caT

guy sergeant wrote:

From the Macondo to the Celestion SL600 ! I cannot think of two speakers that could be more different in terms of design philosophy and (I imagine) the presentation of music. If you can get any noise out of the SL600's I'll be interested to hear what you think of it. They are one of the very worst speakers I've ever heard. The aerolam cabinet is indeed interesting and a good place to start. The rest is astonishingly poor.

Well, at this point I can assure you that you if did not have proper electronics to drive the thing or did not use them properly. May I ask you what is your objection of the SL600’ sound and what “astonishingly poor” you find in their design?

The Cat

guy sergeant wrote:

Hi Romy, My experiences with the SL6 and SL600 date back 15-20 years. My problems with the sound I could get from them related to their inability to recreate music with scale or drama. I found the subjective lack of high frequency output made every recording sound as though it was made in a room lined with thick carpet. I didn't think they were at all good at reproducing the timbre of piano or strings. I can't give specific musical examples, it was too long ago. Their low sensitivity meant that very powerful amplifiers were required. These amplifiers were generally compromised by their inherent complexity and they generally sonded poor on other more sensitive loudspeakers. The best results were probably achieved with a friends home made very large 100 watt Class A transistor amplifier which at least got hold of them a little. While you could hear the benefits of the aerolam box (particularly when comparing the speakers to the wood boxed SL6) the overall feeling was that you were fighting against nature. In a way I felt the same about the contemporary Apogee loudspeakers. Although the sound of these was very different, the type of electronics required again made them uninteresting. I take it that you are enjoying the Celestions. They did get many positive reviews in their time. I never managed to get them to make music sound interesting and even at that time far preferred the results I could get with lower powered valve amplifiers and more sensitive speakers. What do you find to like? Perhaps you should also look out for the peculiar 'beachball' subwoofer they manufactured to augment the bass output.

The Cat

guy sergeant wrote:

What you say may be true. I'm not sure there was an amplifier available in the mid to late 1980's that would have been suitable for these. They did get good reviews but I suspect that some of this was due to awe inspired by the technical achievement of making the cabinet and the laser interferometry images. It was almost as though some reviewers were afraid to criticise them. Presumably they found amplifiers that they felt were suitable. I seem to recall Krell amps being used but I didn't like those either with the Celestions (KSA50 or KSA100) or with any other speakers.      Ah I understand now.... I was probably just using the wrong speakers!!! If there was a suitable amp then, I certainly didn't find it. It did make me question the wisdom of making such a thing (clever cabinet or not) if there wasn't an amp that could make it work.  I'm not even sure a suitable (commercially made) amp exists now. Even if you could make or have made an amp to squeeze some life from them I'm sure that amp would sound much better on more sensitive speakers anyway. I always preferred Peter Snell's original Type K design which was a smallish two way IB with relatively low cost Vifa drivers but which gave far more life and colour to music than I could ever imagine the Celestions producing. I look forward to hearing of your further adventures with them and must admit that if I found a pair I'd enjoy putting a Revelator tweeter in and trying to find a 6" driver I liked. I imagine, given what you said earlier, you'd be trying to reduce the LF bandwidth but this may be throwing away the benefit of the cabinet design. I don't know.

The SL600 obviously should not be used all the way down as those PVC woofer begin to pump air intend of sound. I crossing them (electrolytic with active bias) at +15Hz-60Hz form their natural decay. The Lover sound transferred into my LF line arrays at 60Hz. I was driving them with 5 amps, SS and tubes, including the new full-range Melquiades (in small room it has enough powers to develop good volume as I driving the 6C33C there at whole 60W) All amp made the SL600++ sound like crap: no dynamics, very challenged, very small, diminutive and with all other negative sort of things. Then I brought Lamm M1.1 and it did all necessary things.

I still not there yet as the key is in the very precise cutting off the SL600. I would need to inhale them at the very strange location were they will be living in my room and perhaps then try to optimize them. I will be doing it in a few weeks AFTER I resolve my interest in “fundamentals channel” as I am planning to settled the SL600 on the frame of the “fundamentals chancel” support.

Rgs,
The caT

guy sergeant wrote:

I suppose the question then is, does the SL600 then sound more correct than your normal system with 'better' amplifiers? Don't you still find the sound of the woofer to be too smeared, slow and dark?

Actually they are phenomenally balanced and integrated between the drivers and drivers to enclosure. I did not detect any sound of the woofers at all if I do not overdrive them. As soon I stress them ether with power or with LF frequency extension then they do fall apart. But why does one would go into stressing them with amplitude or with bass? The objectives are very different: do not let them play any stressing bass as all.

guy sergeant wrote:

There must also be some substantial attenuation (20 dB) being applied prior to your bass system to match its output to the Celestions. Isn't the effect of that audible?

Nope, the LF section that use for the SL600 is 88dB and I put the LF on a transition slope.

guy sergeant wrote:

Isn't the character of what the Celestions produce also radically different to that of your bass system?

Hm, it is still to be seen and as it should be properly integrated: something that I did not do yet. It possible that better woofers might be found but between two drivers that I tried I did not find success, including the Utopia drivers that I mentioned above. In fact, I did not think as now that the SL600 have problematic woofers: I believe that they were severally overdriven in the original design.

The Cat

After spending two weeks with high-passed Celestion SL-600 reinforced with external LF section I would like to make some observations. I had a single SL-600 monitor (I always tend to use one for assessment purpose) on it’s original stands in the very middle of my room. The monitor was reinforced with a pair of LF line array on right and left. The monitor and the LF sections were more or less OK integrated (not perfect but survivable), set to be in phase with Celestion woofers. I did not do any measurements as I did not practically cared. The sound was generally very acceptable. Was it be the same as I was getting from the full-scale Macondo Acoustic System? Absolutely not! Macondo has very different presentation and deliver very different drama of presentation. However, the SL600  + all my additions did very good from a perspective of ordinary Hi-Fi. Do you remember how 50K-70K loudspeakers sounded in the rooms of your dealer or at your favorite room of any recent high-end show? The SL600 did more interesting in my room – more “accurate” and with no major sonic “mistakes”. It was perhaps to enough to say that it was as good as I expected but quite reasonable and acceptable for a second system. I have to tell you that I did not mean to put it as “ultimate monitor” as I have a well performing loudspeakers and I do not need two systems. However, the SL600++ might bean excellent low-maintenance “summer speakers” or the speakers that I can run while I am working (that is actually more complicated).

So, I was quite happy with result and I decided to put them at the location where I meant them to sit: to strap them to “fundamental channel” stand. The sunny part that in there the Celestion SL-600 turned into an absolutely unspeakable crap. I can’t believe how bad it was!!! I made some further experiments with them and surmised that they are phenomenally sensitive to everything. The listening distance is very important. If they sit a little too far then I have no HF, if they sit too close then I need to cross them very high, almost at 150Hz. If the SL-600 sit at the location where lower and upper boundary are too close (too tall stands) then the SL600’s woofer couldn’t be crossed at all and can run full range: it sounds very clan and with no distortions at all. However in this case the HF driver dose something astonishing. It begins to sound like you scratch a frying pen with knife with distortions that probably might be over 80%.  I never heard in my life: the “fundamental channel” stand could be moved up and down with a second and the sound of the SL600++ changes from very clean and accurate to absolutely faulty just my moving the speaker with 2 feet vertically.

Rgs,
Romy the Cat

Well, it took almost two month and much more money then I thought but I was eventually able to get very decent sound out of monitors.  The SL600 sitting on my “fundamental channel’s” tripods did not do well as I told before and I was forced to sit them in their original stands. Also, I have concluded that one of SL600 tweeters was defective. It worked fine but it did not sound as good as it did initially. Presumably it went down while was playing in my room. The bad part that I was buying the tweeter 3 times as the few that I have bought did not sound as good as I expected. Took some money to do so, well, “C'est la vie” … Anyhow, all my experiments with better MF driver and tweeter did not succeeded and I end up with driving SL600 as they are, with a moderate high-pass at 70hz. Of course a separate dedicated LF sealed Scan-Speak section compliments the SL600 under the bottom from 100Hz and down.

Wow, what an interesting sound! Different but very interesting! Also, what is wonderful job the Lamm M1.1 does on the SL600. I still would like to have the M1.1 to be slightly less granular and less abrasive but it would take a different amplifier. Still, the M1.1 inhale very interesting sound into the SL600. Surprise, surprise it have very unexpected dynamic sound, despite of its 88dB misery and do not fall apart easily with complex music. I was playing on my new monitor setup the Shostakovich’s 8th Symphony, properly performed and mastered. What an interesting things. The their movement should be Mahler-like effective and cinematographic however it should be also in the Shostakovich unique style be trite and vulgar. Most of audio do it effectively pornographic, stripping that sense of self-duplicated disdain. The M1.1 with SL600 did it right as it should be: a perfect salsaof the dual baby-tornados from movie “Twister” dipped into Russian hair-down self-Moronity and Soviet dancers of comedians…

The only thing is that I feel that I will burn them quite fast. After Macondo, that I generally listen quite loud (because I can) I have tendency to drive the SL600 relatively too hard. Well, if they will not live for long then they will have a good short live (I got a couple of SL6 for parts). I wonder if any cold running, AB, good sounding SS amps out there to make my “summer during global warming” setup?

The caT

Chirag wrote:

My Tannoy 10" sealed box (not tannoys cheap boxes) ….

As I’m learning you was quite wrong in this. Can you tell me more bout the box for your Reds and why fill feel the Tannoy’s original box did not satisfy you?

Chirag,

May ask you: how you drive your Reds 10” and the most important do you feel any their deficiency in power handling. I mean after the 109dB Macondo I have tendency to drive the small Reds slightly hard and this LF drive do not really handle full stress well. I wonder if it Milq is choking on Reds or the 10” reds are fairly fragile.

Romy the Cat wrote:

May ask you: how you drive your Reds 10” and the most important do you feel any their deficiency in power handling. I mean after the 109dB Macondo I have tendency to drive the small Reds slightly hard and this LF drive do not really handle full stress well. I wonder if it Milq is choking on Reds or the 10” reds are fairly fragile. The Cat

Chirag wrote:

You have no idea how masochistic some of the amplifier issues have been with these little speakers.  I know exactly what you mean about power handling deficiencies AND would add dynamic inabilities.  I do think tonality and dynamics can be functions of one another and this is the major reason these undynamic little reds are ultimate dead ends...but they can work in limited capacity for current needs.  The golds and DMT's work better with stress, but cannot hold their own tonally.

The dynamics is an extra subject. The HF driver does surprisingly OK in terms of dynamic. The LF driver is another story. The Reds in a right “untreated” box do their typical “primary resonance spreading” and it certainly do not give an impression of dynamics in the terms as we use to…

BTW, it is interesting that you find the Golds and DMT's tonally challenged compare to Reds. Can you elaborate on it? The Golds need >150W to drive them….