Modula MT-XE - You didn't ask for it... it's coming anyway

[JonMarsh]

Final Schematic Post

Documentation getting wrapped up this weekend- schematic, will be included in the final PDF, of course.

[Johnloudb]

Really nice looking schematic there. Good to see that adjustments can be made for voicing the speaker to ones room, system and listening preference.

Just wondering about the BSC. How far these can be placed out in the room, away from the back wall?

[JonMarsh]

These incorporate full baffle step compensation based on the measured location for the original data- 1 meter out into the room.




I suppose I could have taken that even further, but a speaker of this size is most often used (in my experience) in smaller rooms, and a typical distance from rear wall of maybe 12" to 20", which will warm them up a little bit, in the midbass, but not much- and with the wide power response in the 1 kHz and above area, this doesn't seem a problem perceptually.

Placed in a typical mediocre position 18" from back wall, 28" from floor, which can lump up the bottom end due to the distribution of boundary resonances, they're still quite listenable and not at all heavy, though for someone used to listening to large systems placed close to a wall, they'd probably sound light.

[spadez]

If they are placed only around 4 inches from the wall, is it possible to compensate for that using slightly different resistors, or does the speaker need to be modified more than that?

[JonMarsh]

I tried it about that close, about 6", and I didn't see any issues- it warms up the bass response a bit, but due to the narrow front panel (relatively), the BSC shouldn't be changed even their.

Often with more conventional designs, particularly larger ones, placing this close will tip up the lower end response, which can be a problem if the power response in the upper range doesn't keep up- when I mean power response, we're talking about the averaged response over a large forward arc. The waveguide seems to improve this a lot without making the on axis hot- as a result, they seem less position dependent.

The ones I delivered two weeks ago replaced small set of JBL book shelfs, and the comment of the recipients (family of sorts) was that "everything is more "there" - the highs are clear even over in the living room, the voices are clearer, and the bass is crisp" (that's a direct quote; now, I've never before heard the term crisp applied to bass, but I suppose that's one way of describing articulation?) These were placed on a furniture piece about 10" from the wall.

[JonMarsh]

Re the TMM

A few folks have been asking for details about the TMM, so since wrapping up the PDF is taking a little longer than I expected, I'm posting some of that info now for those who are curious. It's more of a perfectionist design, and some of that is due to the fact there are more issues to address which can arise as a function of the topology.

The notes in the Schematic window explain the what and whys if the "optional" parts are left off to save bucks.

This version I also expect to sit a little further from the wall, and I did some pyscho acoustic tweaking to more optimize the sound for classical music considering the wide power response the crossover and waveguide combination delivers- obviously it's easy for people to tweak that with the same kind of resistor adjustments I outline in the MT schematic. This is what I preferred after a fair amount of listening to one proto in mono.

Re the LF zobel with 12 mH inductor, this can use the skinniest wire imaginable and high DCR; just subtract the value from the total value of R9, though even that isn't critical. HOWEVR, it is flatter with 8 ohms total DCR than say, 10 ohms. I used a Jantzen 18 AWG inductor with DCR of 2 ohms, and 6 ohms for R9; R9 should be in the 50W or more range.



LspCAD Crossover


LspCAD SPL


Transfer function curves for the three drivers.


Impedance plot with input impedance zobel in place.

[Jed]

Hey Jon,

Really nice work and you're pushing the envelop in design, as usual. One question though, do you find the zobel network on the woofer that levels the electrical transfer function around 100hz, as one of those "a-ha" type discoveries that you'll incorporate into future designs as a rule of thumb, or is it something more specific to the variables within this design? Based on the impedance graph and comparing it to what I've seen in the industry, there appears to be more than one reason for its implementation. Really this isn't much of a question, more of a pondering of sorts, but I'm still curious.

Jed

[JonMarsh]

My experience and thoughts on this Jed, are that it seems to be desirable whenever one has a LF crossover function with some drivers (at least the ER18RNX- probably an impedance curve interaction) with a low pass function under 500 Hz, or with inductors in the range of 3 mH + for 8 ohms, maybe 1.5 mH or so for 4 ohm.

The thing is, you can model and measure this interaction with even more conventional two way designs, but the effect is smaller, as regards the amplitude error.

In this TMM design, I felt the amplitude error was serious enough to correct- to get rid of the peaking at 125 Hz and the dip in the 40-50 Hz area. The thing is, to me, it definitely sounds better, too, more articulate and natural- you can talk all you want about amplifier damping impedance, but it's what's happing right at the driver that counts, and as you know, the XsubL impedance as well as the DCR affect the actual driver damping.
With the Ardent and a 4 mH inductor in series with paralleled ER18RNX, the effect is just that much more obvious, as you can imagine, and the need and benefit even more pronounced.

Sometimes people seem to get away without this with somewhat low crossover frequencies- like the Statements - without recourse to LF zobels. OTOH, Curt doesn't show modeled amplitude behavior below 100 Hz. And I suspect it has a lot to do with the shape of the impedance curve, and the degree of phase shift and impedance going up into the 100 Hz area.

With both these and the Ardents I verified the presence of the amplitude anomalies predicted with LspCAD to the measured response, so it's not a modeling quirk.

Practically speaking, I'd only commit to the comment that for these systems, this is necessary to fully optimize the system capabilities. Maybe other drivers and alignments don't need that. I'll put that to the test very soon with the TMWW 2.5 way version of these in development/construction (D2608/9130 + ER18RNX + 2x RS225-4). Who knows? Should be interesting to see how that pans out. At least, I don't think the crossover will be any more complex!! :W

[spadez]

Hi Jon,

Just something I was curious about. You have made a TMM and a TMWW, but why is it there is no modula TMW? This seems like a logical step inbetween the two, with the woofer probably handeling the low end better than a midrange speaker with a low crossover.

Also, am I correct in assuming the TMWW and the TMM use the same waveguide system as the TM?

Schematics looks really good though, thank you for spending the time to put it all on the net for us.

[Jed]

Thanks Jon.

And the new proposed 3 way with the RS225s sounds interesting as well.

Jed

[JonMarsh]

Well, it's more a mad scientist kind of idea, it seems to pan out on paper, but there's many a slip twixt the cup and the lip. I should be doing some test measurements for it and the Modula Xtreme today, the true three way in this series.

Have a good weekend!

[JonMarsh]

Hi Jon,

Just something I was curious about. You have made a TMM and a TMWW, but why is it there is no modula TMW? This seems like a logical step inbetween the two, with the woofer probably handeling the low end better than a midrange speaker with a low crossover.

Also, am I correct in assuming the TMWW and the TMM use the same waveguide system as the TM?

Schematics looks really good though, thank you for spending the time to put it all on the net for us.

Funny thing, I was originally thinking about a 2.5 way TMW at one point, but within the selection of feasible and more reasonably priced drivers (i.e., no driver for over $100), dual RS225-4 seems to make more sense, with only a slight price increase over a single ER18RNX.

And yes, all of these Modula MT variants use the same waveguide/tweeter system with the ScanSpeak D2608/9130 + MCM H-65. That combination is a real honey.

Later today I should be testing the Millenium Excel tweeter with H-65 waveguide for the Modula Xtreme- it's all assembled and ready to go, but it's lunch time!!

[benchtester]

... dual RS225-4 seems to make more sense, with only a slight price increase over a single ER18RNX.

I am following this thread with interest, but I am wondering why and how you are going to use the RS225-4's. Will they be parallel or series? How will this configuration compare to dual RS225s-8's in parallel? (Also, I am under the impression that the RS225s-8 has better low-end extension than the -4.)

Thanks for all the postings.

[JonMarsh]

I am following this thread with interest, but I am wondering why and how you are going to use the RS225-4's. Will they be parallel or series? How will this configuration compare to dual RS225s-8's in parallel? (Also, I am under the impression that the RS225s-8 has better low-end extension than the -4.)

Thanks for all the postings.

Hey, don't worry, this is confusing everyone, I suppose it could be confusing me, too, but I think I have a handle on it! :W

The plan here is two RS225-4 in series for the 2.5 way TMWW. Voltage sensitivity will remain the same for two 225-4 wired in series re overall output as one, but the impedance doubles and the power handling doubles. The RS225-4's in series will constitute the 8 ohm driver for the 0.5 part of the 2.5 way. Target is to have an adjustable alignment via toggle switch for either near boundary placement or placement out into the room, with useful response into the low 30's but rolling off fast below that. These are standalone for music, and if you want true sub like extension, get a sub.

Low frequency extension is dependent on many factors, including ported versus sealed, damping as a function of T/S parameters, particularly Qts, etc. Now, in this specific design, I'm going after some rather specific things- they key point to keep in mind is that this is NOT a three way system, but what I hope is a cunning tradeoff to increase output compared with a straight TMM at little additional expense. The TMM crossover is documented above.

Now, the weirdness or Twilight Zone Factor (TZF) comes in that rather than just adding a second identical midwoofer for the 0.5 driver (conventional thinking - can be a bit of a rut to fall into), I'm going to use a different driver setup. Furthermore, because everyone I know has their significant others always complaining about speakers being too big, I'm playing some games with the choice of driver and T/S parameters and using the Flux Capacitor Alignment (FCA, don't forget that, there will be a pop quiz later) to make trade-offs for enclosure size and roll off rate, and be able to use a larger drive in a smaller box without a bit Qtc bump. Has been done years ago by some companies in England, there are a few things you'd best be careful about it, but the concept has merit, in selected conditions, in my opinion. Properly executed, it seems you can get a well behaved sealed alignment with good damping and passband but with a 3rd order roll off instead of 2nd order. (BTW, ported are 4th order, just to put that in perspective).

I used to be a fan in the 70's of doing weird things to drivers to make them work in unusually small boxes; ask ThomasW sometime about the slot loaded 15" Audax Pro woofers he used to run as subs before building his IB. Designed those in the late 70's; the same driver in a conventional sealed box of the same volume had an Fc of 65 Hz; these were flat to about 30. No getting around Hoffman's Iron law, just playing some acoustic games to make the response work out the way you want in a selected area, and with the sensitivity they originally had, it was no issue. It did require a very low Qts driver to work well- about 0.2.

The FCA alignment doesn't require anything more special that a fairly large VAS and a Qts in the range of 0.45 plus or minus a bit. The RS2225-4 is just fine. The RS225-8 isn't.

I've already modelled this for the RS225-4 and the Scanspeak 26W/12867; I'm just finishing building text boxes this afternoon to verify the hardware. Proof will be in the pudding soon, or I'll be scratching my head with an embarrassed frown...

[villastrangiato]

I've already modelled this for the RS225-4 and the Scanspeak 26W/12867; I'm just finishing building text boxes this afternoon to verify the hardware. Proof will be in the pudding soon, or I'll be scratching my head with an embarrassed frown...

Just curious, I can't seem to find the 12867 version of the 10" Scanspeak - is this a current model? The nearest one I can find that is still being sold is the 26W/8861 which like most Scanspeak Revelator woofers has a pretty high Vas of 234 liters and a modest .31 Qts. Since the Dayton is set at 38 liters - how can these two be modeled for the same box - or am I missing something?

[benchtester]

Just curious, I can't seem to find the 12867 version of the 10" Scanspeak - is this a current model? The nearest one I can find that is still being sold is the 26W/8861 which like most Scanspeak Revelator woofers has a pretty high Vas of 234 liters and a modest .31 Qts. Since the Dayton is set at 38 liters - how can these two be modeled for the same box - or am I missing something?

It's my understanding that the 26W/12867 was a limited "buy-out" special at Madisound; all gone now. I also believe they were an OEM model.

[Face]

Just curious, I can't seem to find the 12867 version of the 10" Scanspeak - is this a current model? The nearest one I can find that is still being sold is the 26W/8861 which like most Scanspeak Revelator woofers has a pretty high Vas of 234 liters and a modest .31 Qts. Since the Dayton is set at 38 liters - how can these two be modeled for the same box - or am I missing something?

http://www.madisound.com/catalog/product_info.php?cPath=45_228_258&products_id=8693

[JonMarsh]

Just curious, I can't seem to find the 12867 version of the 10" Scanspeak - is this a current model? The nearest one I can find that is still being sold is the 26W/8861 which like most Scanspeak Revelator woofers has a pretty high Vas of 234 liters and a modest .31 Qts. Since the Dayton is set at 38 liters - how can these two be modeled for the same box - or am I missing something?

Sorry for any confusion resulting from lack of specificity of my explanation; they've not been modeled for the same box, but for the same type of application- different size enclosures. The RS225-4 is for the Modula TMWW project; the 26W/12867 is for the Modula Xtreme project, which is a true three way.


The published Qts on the 12867T is 0.45, which is about what production 26W/8867 actually are- in the range of 0.4 to 0.45- apparently because the magnets aren't energized as strongly as for the original prototypes on which the 26W/8867 specs are based. The OEM's 26W/12867 were available at a very attractive price, and the resulting system impedance will be a bit more benign with two in parallel on each side. In practice, I think the same design will be realizable with the 26W/8867, with a corresponding boost in voltage sensitivity, and out of pocket cost. :W

[Ray_D]

RS225-8 Data

Jon

Are you basing your comments on the RS225-8 on your own measurements or the PE data sheets? My measurements for four RS225-8s that I have had for several years are quite different that the data sheets for Qt and Vas.

My measurements for Qt are 0.452, 0.480, 0.489 and 0.480 as opposed to 0.38 data sheet; for Vas I got 47.4, 41.1, 39.4 and 43.1 as opposed to 75.3 on the data sheet.

I would be interested in whether others have measured these drivers and have similar findings.

Ray

[JonMarsh]

Was basing comments on published specs and early measured samples... looks like they're slipping from the sound of what you're quoting. When did you buy yours? My RS225-8's are from 2006 or so. My RS225-4 are just arrived (that version has only been out a year and a half or so anyway).

[Ray_D]

In 2006 Sometime

Was basing comments on published specs and early measured samples... looks like they're slipping from the sound of what you're quoting. When did you buy yours? My RS225-8's are from 2006 or so. My RS225-4 are just arrived (that version has only been out a year and a half or so anyway).

Jon

I bought them sometime in 2006 to build some RS225/RS150/RS28 3ways which I did with DM crossovers. I never put them in permanent enclosures though.

I did not have measurement capability then. I bought SE a couple of years ago. I made the measurements recently because I wanted to do a 3-way with a ZA14 replacing the RS150. I did that and subsequently am listening to a RS225/RS180/RS28A TMWW now.

My measurements of other drivers such as RS180s that I have in my HT are pretty close to the data sheet.

Ray

[JonMarsh]

Then you've probably got solid measurements. All I know for certain is that the set of RS225's I got were ordered right after they became available- I don't know for sure if that was 2006 or what...

[Ray_D]

Just in case

Then you've probably got solid measurements. All I know for certain is that the set of RS225's I got were ordered right after they became available- I don't know for sure if that was 2006 or what...

I'll measure them again tomorrow to see if I screwed up somehow.

I know MarkK uses them. Maybe he can chime in with his data.

Ray

[JonMarsh]

Yeah, well I'd gotten turned on to the RS225 when it first came out because of seeing some of the other RS parts up at his place, and his first measurements.

Well, you know what they say, stuff happens. In this case, though, with this funny approach for using small cabinets, I want a Qts in the 0.45 range.

BTW, did testing of the SS 26W/12867 today, and it looks like this technique will work fine for enabling their use in 1 cu ft each without big Qtc bumps in the in box response (for that size, it's about 3-4 dB maxing out at 70-80 Hz. With the right size cap (blue trace), can calm that down nicely as well as extend the low end a bit.



The target for the Modula Xtreme is a relatively small system with very low distortion drivers that is quite clean to somewhat unreasonable levels for it's size. Double 26W's with 9 mm Xmax on tap and a 7" Accuton midrange should do that... :B

[Ray_D]

Re-measured RS225-8s

I measured my four RS225s again. It turns out I did compute the test box volume incorrectly. The Vas did come up some but nowhere near the data sheet. They averaged 49.5 liters which is still a long way from 75 liters. My Qts averaged 0.492 which is considerably higher than the 0.38 of the data sheet.

I suppose I could be doing something wrong; but, it seems straightforward and my other driver measurements seem consistent.

Ray

[JonMarsh]

Thanks, Ray- interesting feedback. That would indicate I could use the -8 also in this sort of configuration- useful information to have.

[evilskillit]

I measured my four RS225s again. It turns out I did compute the test box volume incorrectly. The Vas did come up some but nowhere near the data sheet. They averaged 49.5 liters which is still a long way from 75 liters. My Qts averaged 0.492 which is considerably higher than the 0.38 of the data sheet.

I suppose I could be doing something wrong; but, it seems straightforward and my other driver measurements seem consistent.

Ray

Have the drivers undergone any sort of break in? I've seen some drivers TS parameters change pretty significantly after undergoing a day or 3 of break in. Tho some don't change as much as others tho.

[Ray_D]

Hmmmm

Have the drivers undergone any sort of break in? I've seen some drivers TS parameters change pretty significantly after undergoing a day or 3 of break in. Tho some don't change as much as others tho.

Well, I never did formal break in; but, they have been used since 2006.

Ray

[JonMarsh]

I dunno, Ray, do you suppose 4 years might be rushing things a little? Sometimes I prefer a solid decade of burn-in before serious T/S evaluations... :rofl:

[dmalphur]

Is a circuit diagram or white paper of this "Flux Capacitor Alignment" available? I have 4x RS225-4's that have been waiting around for the right application, and this might be the one.

[savage25xtreme]

these guys stole your bamboo idea!! :rofl:

ascend

[JonMarsh]

these guys stole your bamboo idea!! :rofl:

ascend

No kidding! And I found out at RMAF last October that Bamberg Engineering Sound Lab (BESL) did, too! At least at the show- you still wont' find anything about it (well, I couldn't) on the web site).

And I found out that Salk has been building a system using LBL, too, from a write up about the AK Fest.



About $18K for the pair.

Very industrial looking, if a tad reddish for my preferences. I bet they go deep in the bass, looks like a lot of the effort went there in the HT-4, though I understand they have a 10" woofer version, too, for about $12K per pair.

I just guess I'll stick to my near field mini-monitors like the Ardent. :B

[JonMarsh]

Is a circuit diagram or white paper of this "Flux Capacitor Alignment" available? I have 4x RS225-4's that have been waiting around for the right application, and this might be the one.

Ray

Not really. Basically, it's just using a series cap with the LF woofer, adjusted in value to tweak the response curve by phase shifting the current and killing the Qts peak and extending the low end somewhat. It requires a moderate qts driver with high VAS for optimal behavior. SS 26W's are good candidates; for an 8" 26W/8867, the series cap will be in the range of 400-600 uF, depending on how you want to tune the Q. In the example posted above for the 26W/12867, the blue trace was 400 uF.

It's an attractive proposition if

• You have drivers with a Qts around 0.45 to 0.5
• They have a low Fs free air, and fairly high VAS,
• You want a small enclosure but lots of driver radiating area (swept Sd) to keep the distortion down
• You don't care much about reproducing bass below the mid to low 30's.

I have two system concepts in development/construction using/testing this idea:

a 2.5 way TMWW using modified PE cabs, (derived from the Modula MT MkII)

and the Modula Xtreme, a compact full three way using modified PE cabs, and higher end drivers, including the Accuton T6-C90 midrange, a waveguide tweeter setup, and dual 26W/12867 woofers on each side. Sort of a FrankenSpeaker. Something relatively petite that will hopefully have the SPL and distortion of an Avalon Isis in the 35 Hz to 20 kHz range, but smaller and much easier to build. Not as sensitive as the Isis, of course, only about 85 dB/watt (but that's per watt, not 2.83 VRMS), and very benign to drive. That should still be good for lots of dB's with 100-200W/channel, with dual 10" woofers with 9 mm Xmax.

Of course, the proof is in the pudding, and the pudding hasn't been baked or sampled yet. But enough measurements have been done to establish viable proof of concept. And as Jed documents, the 26W is a very clean machine.

[evilskillit]

I dunno, Ray, do you suppose 4 years might be rushing things a little? Sometimes I prefer a solid decade of burn-in before serious T/S evaluations... :rofl:

HA, yeah I'd call running anything for more than a few days under just about any circumstances a break in. I'd like to know what your idea of formal break in is A week running a sine wave at its resonant frequency at xmech?

[Dennis H]

Paul Hilgeman was the first one I saw use LBL several years ago in his commercial Ronin (custom OB coax with a Dayton bass bin). His stuff is a little different with flat bamboo sandwiching the vertical plies.

[BOBinGA]

Originally Posted by Ray_D
I measured my four RS225s again. It turns out I did compute the test box volume incorrectly. The Vas did come up some but nowhere near the data sheet. They averaged 49.5 liters which is still a long way from 75 liters. My Qts averaged 0.492 which is considerably higher than the 0.38 of the data sheet.

Ray,
Your RS225 measurements still do seem a little off. When you made your measurements, did you use the spec sheet Sd of 216.4 cm^2 or did you use your own measurements? If you used your own, did you remember to subtract the area of the phase plug since it doesn't move? I don't think this will account for the entire difference, but I have seen it make a significant difference when I input driver data into WinISD.

I'm interested since I have an old pair and I don't yet have a way to measure the TS parameters. Thanks,

-Bob

[JonMarsh]

Paul Hilgeman was the first one I saw use LBL several years ago in his commercial Ronin (custom OB coax with a Dayton bass bin). His stuff is a little different with flat bamboo sandwiching the vertical plies.

There are a number of different laminated bamboo constructions available, some more readily than others- I've seen the one you show in pictures, but haven't come across a vendor carrying it.

[cjd]

I've talked to folks about using bamboo for ages (including, IIRC, Paul H - I don't know if he tracked down a source using info I had on hand or he found one elsewhere) - I don't even remember where the topic first came up but I was thinking of using it even back when he hosted the first ever DIY event I attended.

I usually start by giving Teragren a call to find out who warehouses the stuff semi-locally. In most cases I would have to either order an entire bundle, or I'd have to find a 3rd party that buys regularly and go in on some with them.

The various counter-top LBL Teragren has are awesome, sometimes quite stunning.

[Dennis H]

Looks like Paul is throwing in the towel on being a speaker manufacturer. Tough business! His web page is down and there's a goodbye message at audio circle.

[Ray_D]

Data sheet

Ray,
Your RS225 measurements still do seem a little off. When you made your measurements, did you use the spec sheet Sd of 216.4 cm^2 or did you use your own measurements? If you used your own, did you remember to subtract the area of the phase plug since it doesn't move? I don't think this will account for the entire difference, but I have seen it make a significant difference when I input driver data into WinISD.

I'm interested since I have an old pair and I don't yet have a way to measure the TS parameters. Thanks,

-Bob

Bob

I used 216.4 cm^2.

Ray

[BOBinGA]

Thanks Ray.

For the guy that asked about a formula for flux capacitors, see Tony Gee's Black Box design over in the PE Projects site:

https://www.parts-express.com/projectshowcase/indexn.cfm?project=blackBox

Tony is the only designer I know that can make Jon's crossover and box designs look simple, but he has some good info on his Humble Homemade HiFi site.

-Bob

It looks like Emotiva uses flux capacitors in their big speakers:

[spadez]

Hi Jon,

Are the drivers you have in mind for the Xtreme set in stone, or could they change? Im just trying to get an idea if I could afford the xtreme system.

[JonMarsh]

Well, the Xtreme, being a three way, may not be "set in stone", but perhaps, "cast in ferroconcrete"?

The midrange driver is a given; it's the highest performance large cone midrange I know of.



The woofers are extremely clean, and the system could be built with the 26W/8867 instead of the 26W/12867; I chose the latter because they were available at a better price.



The tweeter may still be pending on tweaking the Millenium Excel throat behavior, but I am committed to building up the first cabinets for that, and have already started them.


That said, there must be spy cams around here, the questions you guys keep coming up with, as I have been considering the possibility of documenting a lower cost version of this design (couldn't call it the Xtreme, though, could we?) using RS270 on the bottom end, possibly a Vifa NE180W on the midrange, and the ever popular Scanspeak D2608/9130 on the top end.

What would I call that? The Modula SO Xtreme? (Sort Of) Or Modula Xtreme SO?

I'm sort of joking about that, but I've got most of the drivers on hand to test for that, just waiting for the NE180W, which based on the impdeance curves, ought to have pretty low midrange distortion and excellent lack of rear masking. But it's not here yet, and not tested. I'm leaving for a week of business travel on Sunday, so I won't have any answers to the possibility of the SO version until next weekend earliest.

Keep in mind that for a sophisticated three way, the crossover expense is substantial whether you use Scanspeak and Accuton drivers or Dayton and Vifa. Though obviously, there are some possibilities for substitution with regards to the crossover component cost, parts, like the tweeter caps, which could be upgraded later.

Once again your clever questions are leading me to tip my hand a bit early...

[ergo]

Not same, but for reference one more method to push midbass low end up... (with real woofers the losses would be too big likely)

http://sound.westhost.com/articles/pikku9.htm

[spadez]

Sweet Jesus. The mid range speaker (C173N-T6-90) is nearly $900 by itself! I guess the Xtremes are out of my budget!

I look forward to seeing the info on them though