Driver Evaluations for a new project

[Bear]

Someone didn't know what they were doing. Perhaps they were relatives or associates of Captain Needa.

Perhaps it is karma that they should fail?

http://www.marten.se/pdf/Marten_Coltrane_Soprano_Brochure_150dpi.pdf

vs.

http://www.kharma.com/exquisite/kharma_loudspeakers_exquisite_mini.php

A different model, granted, but the designs have a bit too close of an outward appearance for my suspicions not to be raised a little about who's copying whom (or OEMing, for that matter). I am curious whether they are using the '96 driver, or a custom one, though. I believe the consensus from the RMAF reports was that they are using a custom/OEM-only unit.

[JonMarsh]

Yes, Kharma is a b*tch, isn't it?

I've heard the standard Marten Coltrane, and with an adequate amplifier on the bottom, it's pretty decent- but "adequate" is the key word, as it's a punishing 2 ohm load over much of the bass range. Something like an ASR Emitter II Exclusive is what you need driving it.



It's funny because I've been going back and forth in emails with our division head in Austria over Eidolons, the Marten Coltrane, and the Kharma Mini's, as well as Indras, and tomorrow he takes delivery of a slightly used but pristine set of Mini's. For his setup, I think he's going to be pretty happy, though myself, I might have preferred the Eidolons. But then, I'm more familiar with them, too, with more listening hours and actual measurements under the belt.

[Face]

That's a pretty beefy(but ugly) amp. 900wpc into 2ohms should drive just about any home speaker. But for $25K, it should.

[JonMarsh]

Actually, you know, it's an integrated amplifier. Very well designed low impedance power supply, too- no corners cut there. Effortless dynamics, very resolving. Yes, a tad pricey- as most high performance German products are... :W

[chrismercurio]

Just by a 1000 watt amp and you don't have to worry about sensitive speakers. :-)

I respectfully disagree.

Power compression on a driver of low sensitivity is very audible if compared to a driver of high sensitivity. With one, the driver gives out before your ear, and with the other your ear gives out before the driver. I prefer the latter.

I'm not advocating listening at high spl's either, just the difference in sound approaching louder SPL's. The audibility of dynamic contrasts IMO are buried in systems of lower sensitivity even with a ton of power on tap.

[JonMarsh]

I think Jed was kind of joshing with us....

Somewhere between speakers that are 80 dB/watt and those that are 100 dB/watt must be a happy medium... which suggests 90 dB/watt, which is roughly where I'm aimed these days. :W

[Jed]

I think Jed was kind of joshing with us....

:B I should have added MR. Green to that 1000watt comment.

The smiley evidently didn't convey my sarcasm strongly enough. However in effective sarcasm there is always an element of reality. The audiophile that chooses a 10watt single ended tube amp to drive a 3ohm 82db/watt speaker and complains of limited dynamics comes to mind. An extreme example, I know, but not all that uncommon.

I know a thing or 2 about how to achieve dynamics, and using multiple woofers (line arrays etc) is one such recipe. Having enough power to do the job is another. I ponder if the audiophile that complains of a lack of dynamics is hearing clipping of the amplifier or compression? That only can be answered after evaluating the specific system. Otherwise, as Jon mentioned, we can only generalize. I like the 90db compromise.

[cjd]

90dB works well for me too - been building to that target for a long while and like it.

[JoshK]

I prefer 93-95db/w cause I like 40w and less amps better than most any 100w+ amps I've heard (limited to what I've heard).

[JonMarsh]

Well, I'm mainly using a 60/120 per channel amp right now-- so it really comes down to what your SPL target and room size is. The amp is an integrated with an essentially passive line stage, with FET switched volume control, and no loop feedback on amplifier- very clean mids and top end for solid state.

With 90 dB/watt, one won't need much over 10 watts most of the time- for 99 dB. Extended listening over that level can be detrimental to your long term hearing. Let's allow another 12 dB or so for peaks? 110 dB? 40 watts, basically, at 8 ohm, 80 watts at 4. So my 60/120 for 8/4 ohms looks in the ball park, unless I get a bigger place and start throwing big parties... :W

[JoshK]

Agreed for the most part. Actually I am running a 15w SE KT88 amp (with local feedback, coined e-linear) on my Modula MTMs right now. With the exception of rather complex music at average volumes >90db, it shows no signs of audible distortion. If I plop in Tool and crank it to 95db average, the complex portions show some signs of audible distortion.

It was rather a surprise that I could actually drive the 4ohm moderate efficiency speakers as loud as I have with a 10-15w amp (depending on where you define clipping).

[Jed]

Well, I'm mainly using a 60/120 per channel amp right now-- so it really comes down to what your SPL target and room size is. The amp is an integrated with an essentially passive line stage, with FET switched volume control, and no loop feedback on amplifier- very clean mids and top end for solid state.

With 90 dB/watt, one won't need much over 10 watts most of the time- for 99 dB. Extended listening over that level can be detrimental to your long term hearing. Let's allow another 12 dB or so for peaks? 110 dB? 40 watts, basically, at 8 ohm, 80 watts at 4. So my 60/120 for 8/4 ohms looks in the ball park, unless I get a bigger place and start throwing big parties... :W

Jon don't you still use the bigger Ayre amplifiers?

[Paul Ebert]

An appropriate midwoofer driver?

Now, this is the kind of product which exhibits the engineering workmanship and aesthetic suitable to being incorporated in an Imperial Advanced Research and Development Lab project...




One would hardly be surprised to find these in the sound system of a Tie Fighter or Bomber....

And one will be in the lab for testing this week. The ARDL division has already done a computational analysis of the engineering parameters for the new project, and it appears promising... most promising.

Were the results of this testing posted? Very curious how it fared.

[JonMarsh]

Jon don't you still use the bigger Ayre amplifiers?

Yes, but I have a smaller Ayre amplifier I like better... sounds weird, I suppose- but the AX-7xe integrated is sort of a passive preamp setup- FET switched metal film volume control, the extra gain is built into the power stage, so there aren't two gain stages. It's a bit more transparent than the combination of K5xe preamp and V5 power amp; just as the combination of Marchand PR41 passive preamp with Shallco attenuators with the V5 is.
Mine has been tweaked a bit, too, with regards to bypass capacitors in regulators.

The K5xe is a very good preamp for it's price class, fairly transparent and only very mild sins of omission, and a lot of useful functionality. But the AX-7e also has balanced inputs, because the power amp is balanced all the way through.

Image not available

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Now, I suspect I could get just as transparent sonics if I could spring for the KX-R preamp, to use with my V5, but you know, I just don't see an $18,500 peamp in my future any time in the near future! :W

So, for now, I'm curious to see how much I can optimize the experience with the AX-7e, with a speaker project sort of focussed on it's capabilities.

[cjd]

I feel better thinking about the K5xe now... will take a while to get the SO approval though.

[Bear]

Evil Twin - Thank you for providing your humble servant with the confessions of the traitorous rebel scum back in post 57. The SEAS ER18NX seem to be competitive with any of the higher-end products produced by TIE industries, but at a price that will not excessively deplete the imperial treasury. Since this latest Death Star will have not one, but two, main cannon, does this imply that your Lordship has made a final selection?

Your humble ursine servant!

[Evil Twin]

Your perceptions are strong in the Force, Bear. This seems the most reasonable choice for the initial prototype configuration- T/S alignment, sensitivity, and acceptable distortion behavior over a moderate dynamic range have come together with a cost factor not usually expected. The Emperor may not be completely pleased with this outcome, but there doesn't appear to be a superior alternative.

[Jed]

Your perceptions are strong in the Force, Bear. This seems the most reasonable choice for the initial prototype configuration- T/S alignment, sensitivity, and acceptable distortion behavior over a moderate dynamic range have come together with a cost factor not usually expected. The Emperor may not be completely pleased with this outcome, but there doesn't appear to be a superior alternative.

Have you looked at the W18NX? Might be a touch better through the midrange.

At least according to JKrutke's tests. The Usher's look interesting as well.

[Evil Twin]

Reasonable suggestions- it is unfortunate that Zaph has measurement issues when he ran the W18NX. MarkK's tests show the ER18RNX beating out the standard W18 on the low end, and in the troubled times, the Imperial treasury has limited funds for further investigations.

In this application, the performance above 450 Hz will be less critical, as the nominal crossover point with the newest target function is about 300 Hz, with midwoofer response down -20db at 900 Hz.

[dwk]

In this application, the performance above 450 Hz will be less critical, as the nominal crossover point with the newest target function is about 300 Hz, with midwoofer response down -20db at 900 Hz.

Interesting - this is a fairly significant change from the preliminary targets that were discussed. Is this to take advantage of the capabilities of the chosen midrange, or driven by other goals?

Is the prototype lineup complete, then? 27TBFCG/RS-100/ER18NX, or is there more evaluation pending? Counting on my fingers, this looks like ~225 per speaker in drivers; RS-180 would drop that by about $60 per.

[Evil Twin]

You are correct, in that the target has been modified to more completely use the capabilities of the midrange drivers- ongoing system modeling has suggested a modified path.

The current plan is to develop and test two configurations- one for the diligent constructor of more modest means, using the RS180's, RS100-4, and 27TBFCG, and one with less restraint on the finances, using the ER18RNX, C79-6, and the D3004/662001. The primary front panel construction will be nearly identical, as the rear masking issues with the RS100-4 suggest the use of an aluminum mounting panel, which will be sized to match the frame outline of the Accuton C79-6.

Before finalizing the target functions and crossover design for either configuration, measured and subjective testing will be initiated using the LspCAD emulation function, checking axis and polar response, vertical window, and swept distortion.

Cabinet and tooling fabrication has begun, but is expected to require an intensive two week effort in late June to be ready to begin final acoustic investigations.

If the project design and construction is completed with satisfactory results, a comprehensive PDF of the design and fabrication process will be available to download, regardless of Imperial or Rebel alliances- the only caveat would be to be careful not to bite off more than you can chew.

[HYPERTUNE]

ET, I have a question for you regarding the woofer/mid XO point.

(Bearing in mind that I am a complete novice with little idea what I am talking about)

I would have thought that the crossover point would ideally be a little higher to make use of the sensativity gain from the dual woofers for BSC? Obviously you have taken all aspects into consideration with the XO point choice, but I have assumed that BSC would be the main reason behind having 2 woofers in a TMWW design.

EDIT: I want to make it clear that this is a question, not a suggestion. I know my place....... ;x(

[Evil Twin]

Many possible solutions

Your question is not unreasonable- there are many possible ways to implement a three way system, some using "tricks" to allow the LF drivers to implement much of the gain needed for BSC- Wilson Audio is a frequent practitioner of this, as exemplified in the original Watt/Puppy, and X1-SLAMM.

Another reason for asymmetric crossovers of this type is reduction of component count- but as can be seen in the measured performance of the Avalon Indra, this often results in deleterious behavior in the crossover region, as well as the overall characteristics.

In a three way system, it is the Emperor's belief that overall integration is of paramount concern, as well as using the drivers in the frequency ranges for which their linear and nonlinear distortion is low. Furthermore, some crossover targets work well in light of BSC issues, and can utilize this as part of the overall transfer function, while ensuring that the polar response in the midrange is fully optimized.

More will not be discussed at this time- let the Rebel scum figure this one out on their own.

For illustration, the current acoustical target and basic network topologies are shown below- driver designations were only placeholders with no meaning to mislead Rebel spies.

Basic Network Topology




System Acoustical Target Function, Amplitude and Phase



Crossover and driver behavior should track to the -20 db point; below that deviations will be less critical.

[Jed]

Reasonable suggestions- it is unfortunate that Zaph has measurement issues when he ran the W18NX. MarkK's tests show the ER18RNX beating out the standard W18 on the low end, . . .

Understood.... for the record the W18NX has an updated motor-- not the standard Excel Magnesium cone version.

[HYPERTUNE]

Thanks for the explanation ET. It will be interesting and educational to see the final results of this project.

One thing's for sure, I'll be building a pair. :T

[will1066]

....

[cjd]

And still beyond what my wife things I should spend on gear...

[JonMarsh]

The K-5xe just got an upgrade kit from Ayre called MP. Still trying to figure out what the upgrade entails. Don't know if this will change your perspective any, but from what Michael at Ayre has told me, the MP upgrade brings the K-5xe thisclose to the K-1xe performance-wise.

Are you sure that isn't the CX-7e and the C-4Xe that got the MP kits? This is a new digital filter using apodizing minimum phase filter for digital playback; as in the past they've implemented a "measure" mode and a "listen" mode; both modes eliminate all pre-ringing that conventional FIR linear phase filters have, and the "listen" mode only has one cycle of post ring at a relatively low level. It's implemented in custom FPGAs as there is no off the self solution in current TI digital chips. The only other player or DAC I know of implementing this is the new PS Audio Perfect Wave DAC released just the end of May.

Chris, I understand your "pain".... hope you can eventually get to where you want to be- the best recent upgrade I did was the PS Audio DL III. Not that bad at $699. But now I'm agonizing over when I can eventually scrape up the moola, to go with the QB-9 Ayre, or a Perfect Wave. Both from Boulder, not too different in price, but the Perfect Wave has a lot more networking functionality and some other cool features... and also has SPIDF and optical inputs- the Ayre doesn't, as it only has the asynchronous USB re-clocked interface licensed from Wavelength. That means it could run from my Mac Mini, but not from my Marantz SA-11 or Cabridge Audio CD player. The perfect wave does have those interfaces in addition, plus it's approach to jitter, the time lens.

Decisions, decisions. Well, no issue now- no money- but Christmas time, well, we'll see.

[Jed]

Jon,

How does the PS Audio DLIII compare to your Cambridge CD player? The Cambridge Dac Magic also looks like an interesting budget choice, but if the PS Audio DLIII is better than your Cambridge, I may spring for the PS Audio.

[JonMarsh]

Hello Jed,

I find that the DL-III bests the analog output of the Cambridge 640C and the Benchmark DAC1- I gave ThomasW a "money back" offer that he should go buy one, and if he didn't like it, I'd take it off his hands for what he paid, as I could use a second one. :W I bought the Cambridge 640C after the DL-III, to use it as a CD transport so I wouldn't be putting hours on my SA-11 just for CD playback. The 640C has pretty low specc'd jitter- 180 ps. Now the Marantz is reserved for just SACD. Those laser read optics have a finite lifetime, then you have to replace them.

I have heard nice things about the DAC Magic, but haven't heard it in a system I'm familiar with. From auditions and word from friends in that price range, the Musical Fidelity VDAC is probably the unit to beat, it's getting fairly close to the DLIII. Three years ago you couldn't buy that level of performance for under about $1K to $2K. A colleague in Europe got a VDAC recently and it compared very well with an EMM labs player on CD.

The only thing putting me off on the QB-9 is that I would only be able to use it with my Mac Mini music server, or another USB source. No SPIDF coax or optical input. I understand the reasons Charlie did that, as this allows them to have data clocked just to a local clock, and no ASRC errors or colorations, but then PS audio clocks in the data on the other inputs and can run it off the local clock, too, so that may be the way I have to go in the end, with the Perfect Wave DAC, for the flexibility.

[cjd]

Hmmm. The PS Audio pre-amp might serve - only one XLR input but I only have one balanced source (my DAC which is a TwistedPear Audio kit) right now... I could always build an external source switch. Interesting. Thanks for mentioning them.

I'm also intrigued by the upcoming Emotiva balanced pre but am a little hesitant on that brand. I've heard some of their gear but everything in that system was new to my ears so I don't know where the disappointing results originated.

[JonMarsh]

I'm also intrigued by the upcoming Emotiva balanced pre but am a little hesitant on that brand. I've heard some of their gear but everything in that system was new to my ears so I don't know where the disappointing results originated.

That can be a bear to figure out, particularly on short notice. In the past, because of all their power conditioning stuff and brouhaha, I didn't take PS Audio very seriously, but the DLIII and the matching preamp appear to be pretty good units and good value. I'd certainly be curious to hear one; they do use a gain cell type approach without a conventional volume control attentuator; I'm sure the implementation is very different from the Ayre KX-R, but the basis of the concept is not dissimilar in it's advantages. If I didn't have a K5xe, I'd look at the PS Audio P200 closely. I expect from the reviews I've read that it's a serious contender at and beyond it's price range- certainly one to give serious thought to.

[Jed]

Jon,

Thanks for the recommendations. I've found your taste in source components and amplification to be spot on, so I'm going to give the PS Audio DLIII a try with the Ayre AX7e I just picked up to replace an Aragon 8002.

Jed

[JonMarsh]

I don't think you can go wrong for that price- and with the return policy available at Audio Advisor, there's little to no risk.

[cjd]

Ahh drat. I misread. No XLR input on the PS Audio pre.

[JonMarsh]

Not So - only one, but it does have one.

[cjd]

Pictures on their website and the description don't fully match. And the pic on AudioAdvisor definitely does not have the balanced inputs. Somethin's up...

[JonMarsh]

I dunno, Chris, have you been hittin' the beer a bit this afternoon? On the PS Audio website, For the P200, features and benefits list 3 RCA inputs, 1 balanced input. The text block description says the same thing.

BUT you are right that there's a graphic showing a version of the preamp which only seems to have three inputs- and that is depicted in the owners manual PDF on the AudioAdvisor site. And the manual on the web site which is a combined control amplifier and preamp manual (two products), shows the three input version.

Me thinks this may be a case of two versions of the product; if you have a serious interest, I'd call PS Audio and check it out; the price is the same from either source. It wouldn't surprise me if they upgraded the configuration to the four input version with a balanced input. Of course, stuff does happen, and I suppose it could have gone the other way. THe RCA over the balanced input and the balanced input appear to both be on #1, so it's probably one or the other. But this is contradicted by the text verbage on the "Additional Product Information" page, which indicates the remote can select from among four inputs.

Could be that Audio Advisor has an "older" version without the balanced inputs. You can internet order direct from PS Audio. One of these sold near new on Audiogon from a dealer, a customer order that wasn't picked up, the "current version with the balanced input". This suggests ordering from PS Audio or a dealer to get this configuration.

[will1066]

Are you sure that isn't the CX-7e and the C-4Xe that got the MP kits? This is a new digital filter using apodizing minimum phase filter for digital playback; as in the past they've implemented a "measure" mode and a "listen" mode; both modes eliminate all pre-ringing that conventional FIR linear phase filters have, and the "listen" mode only has one cycle of post ring at a relatively low level. It's implemented in custom FPGAs as there is no off the self solution in current TI digital chips. The only other player or DAC I know of implementing this is the new PS Audio Perfect Wave DAC released just the end of May.

Yes, I'm sure, since my K-5xe has gone into Ayre HQ for the MP update. I'm fairly sure it's a different kind of upgrade kit than the filter-based MP update used for the C-5xe and CX-7e, and Ayre has decided to just called it MP for linearity's sake. I've got a C-5xe that I want to send to Ayre eventually for its update, too.

[AJINFLA]

I prefer 93-95db/w cause I like 40w and less amps better than most any 100w+ amps I've heard (limited to what I've heard).

Josh, I might be mistaken, but weren't you one of the people who went and listened to Dr Geddes setup? What's all this about 93-95db and 15w??

cheers,

AJ

[cjd]

if you have a serious interest, I'd call PS Audio and check it out; the price is the same from either source.

Oh well, if you'd do that for me, that'd be awesome!... :P

I was going to call them when I get a moment.

(and I don't seriously think you'd be calling for me, just having fun with written language being a bizarre and twisted means of conveying information)

One input on my DAC seems to have gone all fuzzy Ahh well. Probably just a dirty switch. Maybe.

How's the speaker project coming?!

[ThomasW]

FWIW, we just upgraded the K-5xe to the K-5xe MP. In this case "MP" stands for "Maximum Performance" and not the "Minimum Phase" of our digital products. We changed the output stage from bipolar transistors to JFETs.

New price is the same. All units purchased after 12/01/08 get a free upgrade. Units purchased before that can be upgraded for a nominal fee, about 12% of the cost of a new unit. Call Michael at 303-442-7300 x223 for details and a time slot. The upgrade is handled through your local dealer but the unit must come back to the factory for the work.

....

[JonMarsh]

....

Is yours scheduled yet? :W 12%, mmmm, that's about $600? I think there's a Bay area dealer I could get mine done through, though I'd rather send it direct.

[ThomasW]

You would send yours directly to Ayre after scheduling a return date with Michael.

[JonMarsh]

Oh well, if you'd do that for me, that'd be awesome!... :P

I was going to call them when I get a moment.

(and I don't seriously think you'd be calling for me, just having fun with written language being a bizarre and twisted means of conveying information)

One input on my DAC seems to have gone all fuzzy Ahh well. Probably just a dirty switch. Maybe.

How's the speaker project coming?!

Hey Chris,

What good are all those unused minutes on my iPhone if I can't use them in a good cause? :W I'm sure I can fit it in this morning sometime... :W


Well, it's getting down to the wire to start Speaker Camp '09 this coming weekend. The last of the materials and tooling on order is trickling in (yesterday was the arrival of sorbathane sheet, some veneering tools, and threaded inserts for the driver mounting).

I've got a back order to pick up at Woodcraft Friday, and some more glue (I'm finding I have a fondness for Titebond III after trying it out, compared with II for some kinds of work).

Every day I'm usually spending at least an hour on a panel layup operation (all of the enclosure walls are glued up layers of MDF/HDF; takes time for panel pre-assembly, that's been going on a few weeks- the raw front panel pieces for the "premium" set are almost finished in preparation, the secondary set will be shortly behind them). There's more CAD work to be done, and veneer prep; on this weekend I'll be doing a mix of veneer prep and drying, panel layup, CAD design, and fixture construction; with three working areas, stuff can be drying or stabilizing in some areas while I'm working in another or making sawdust in the "shop" area or working on the Mac.

I'm going to turn ET loose on some of the more difficult construction tasks, that require a "can do" attitude at any cost, in addition to the measurements and crossover design. As he is wont to say, "Don't send a Jedi Padawan to do a Sithlord's job". Thinking outside the Deathstar seems to be his specialty, of course.

With the "two" of us involved, since many operations are "hurry up and wait" kinds of things, with a little intelligent interleaving "we" should be productive and not too busy.

The web site is in preparation and being updated as steps are completed and documented; it should be ready to go up quickly at some point; perhaps it'll get launched in mid process.