Ardent Speaker Camp

[JonMarsh]

Parts Connexion has 15% capacitors till the end of the month.

Yeah, I got their update, too- for their sale- will be looking closely at various sources this weekend, though in some cases there aren't that many options. Parts Connexion doesn't carry Clarity caps, so I've already got a big order off with Madisound that's supposed to ship today. I'm becoming a fan of the ESA and MR series, I'm afraid. :W

[Face]

I'm also a big fan of those...in fact, in some applications I like them better than the cheaper Duelunds.

[JonMarsh]

Just received a nice sized box stuffed with ESA caps. :W


And as promised, an impedance curve for the curious.



And lest some folks start complaining, we should remember the Illuminator IS a 3 ohm tweeter...

[bigg]

Yeah, well MDF totally screws up the tone by absorbing a lot of the sound itself and having resonance at relatively low frequencies- dense hardwoods affect the tone by NOT absorbing sound and being quite stiff.

I'm not trying to start a religion here or anything- would be happy if others took this to heart a little and thought about it- but in a sense, it doesn't matter personally to me if anyone does or doesn't in the DIY community. Wouldn't want to be accused of keeping good ideas to myself, but realistically, everyone does what they want...

If I viewed this as a competition or a Sith Lord kind of thing, I wouldn't talk about it at all, I suppose... :W

Thanks Jon for all of your insights. :thanku: I'm looking forward to trying some different builds for the front baffle. The way you built the front baffle for the Ardents interests me. Also the LBL MTM baffles you showed. I just don't know if I can afford the LBL. I'll have to check prices/availability in my area.

I have built speakers with solid Oak or Cherry over the MDF. And, in the case of my daughter's solid Oak over MDF monitors, the speakers are mounted into the solid wood. People are always impressed with the speakers I built for her (I built her a matching powered sub as well) but I don't know if it's because the drivers aren't mounted into the MDF or for some other reason. It was totally my own design and I didn't build another with the drivers mounted into the MDF to compare.

BTW did you ever find the crossover plans for your daughter's Modula MTMs with the Hi Vi D6.8s?

The Madisound Swifty kit is pretty close to what I built for my daughter. I built a set of Swiftys for my Mom but she doesn't want them anymore (she's getting pretty old and is getting rid of things, and she doesn't want to acquire anything else) and they have solid cherry over MDF.

I used to play piano, drums some guitar and my cousin let me play his trombone a couple of times. It's been 35 years or more since I played in any kind of band. I have an Epiphone Les Paul Studio guitar that I like to play with but I'm not any good. It seems like every time I'm going to go practice I get distracted by speaker building instead.

Please keep sharing your ideas, experience and knowledge with us newbies.
We're not worthy ;x( ...we're not worthy ;x( ;x(

[JonMarsh]

These little pretties are a bit large, but should do nicely in the midrange and tweeter sections...

[SoundOfNothing]

And how much did those set you back :E

[Bear]

And how much did those set you back :E

http://www.madisound.com/catalog/product_info.php?manufacturers_id=170&products_id=8617

[JonMarsh]

Hey, at least I got the 10 piece price on both types...

You don't even want to ask what the Clarity MR's go for - this is the reduced cost version of the same technology approach.

[JonMarsh]

BTW did you ever find the crossover plans for your daughter's Modula MTMs with the Hi Vi D6.8s?

(

Yes, I just had to go find them again, but it's an MT, not an MTM. Could be changed into an MT, like the difference between a Modula MT and a NatalieP; which do you need?

I have an Epiphone Les Paul Studio guitar that I like to play with but I'm not any good. It seems like every time I'm going to go practice I get distracted by speaker building instead.

(

I know that feeling- it's been ages since I've owned an instrument and I quit playing for money in the mid 70's, last gig I played for fun and a little money was 1986. I've forgotten huge amounts of keyboard chops and I'd be embarrassed to pick up a guitar, but every couple of months I think, gee, it sure would be fun to get another SG custom (they make a replica of the original I used to have), or a Korg BX3, which is the closest thing I've found to the sound of my old Hammond at a reasonable price.



But other things get in the way... you know, SG Custom? Or Berkeley Audio Alpha DAC? SG Custom? Alpha DAC? At the end of a long day, right now the Alpha DAC seems a better deal for listening to music and enjoying the fruits of the DIY work.

Thanks for the kind words, but we're all here to learn together.

[JonMarsh]

Slow work takes time... today was frustrating, many interruptions! Top facet bevel veneer trimmed, a little tricky due to angles. Will start earlier tomorrow!



As slow as I am, watching the progress is too much like watching paint dry! So many details... the bases are looking good, too, though.

[dlr]

Yeah, well MDF totally screws up the tone by absorbing a lot of the sound itself and having resonance at relatively low frequencies- dense hardwoods affect the tone by NOT absorbing sound and being quite stiff.

When I see some sort of reputable objective measurements that support this, I may accept it. It would be a simple test to make, it takes nothing more than making an impulse (MLS) test comparison of a typical baffle made from each material. MDF and whatever other hardwood might be desired could very easily be tested in a comprehensive and appropriate manner. Forget any extensive bracing since that significantly alters resonances, maybe good, maybe bad.

An impulse response will show all resonances or lack thereof and the wideband response. Yet I have never seen such. All I hear is conjecture on both sides. If mdf absorbs too much, it will show. If hard wood does not and is stiff enough, the resonances will be that of the driver alone. Use the same driver, normalize to a reference you have the material signature. Normalize one response to another and voila, pure objective evidence for absolute difference of materials.

Of course having a reference would be useful. Manufacturers' anechoic measurements would have to be analyzed, I suppose. What wood do they use for their anechoic chamber tests? Maybe they are tainted, I suspect that they must not use brick walls. I do suspect that they use rather serious materials, but someone will probably question anything as a reference. We're left with our ears and our beliefs in that case.

There's way too much subjective guessing on this topic from my reading. There isn't any serious research conducted that I've seen. It just keeps see-sawing with no one taking the extra, reasonable step of trying to get objective evidence when the capability exists. Then I have to ask, why not? I'll bet though, that B&W (how about a Matrix?) and a few other manufacturers do have that data, but they keep it internal.

I think that it could be done reasonably in the DIY community. The problem would be that there would be those who would nt accept the data if it was counter to their beliefs. It would please me no end to see something objective that is rigorous.

Dave

[Biff]

One I know of

At Thiel they use a two or three story vertical column of cinder block/brick construction and have what looks like almost an airlock that they slide the speakers in on their backs lying in a padded cradle. The techs say you can't hardly stand up inside, the ear just goes nuts without input or reflection - sounds a bit apochryphal , but allows them a minimal footprint with an extremely strong structure and various measurement distances.

[dlr]

At Thiel they use a two or three story vertical column of cinder block/brick construction and have what looks like almost an airlock that they slide the speakers in on their backs lying in a padded cradle. The techs say you can't hardly stand up inside, the ear just goes nuts without input or reflection - sounds a bit apochryphal , but allows them a minimal footprint with an extremely strong structure and various measurement distances.

Been a long time since I went to their site, but last I saw they used mdf, very thick, very well braced, very heavy. I have a hard time believing that there would be a significant improvement if they used multiple layers of hard woods. I do believe that it would be easy to prove/disprove. It's simply a case of standard acoustic measurements. I would bet that Thiel has info on that as well.

Dave

[Curly Woods]

Been a long time since I went to their site, but last I saw they used mdf, very thick, very well braced, very heavy. I have a hard time believing that there would be a significant improvement if they used multiple layers of hard woods. I do believe that it would be easy to prove/disprove. It's simply a case of standard acoustic measurements. I would bet that Thiel has info on that as well.

Dave

The biggest problem with using all hardwood for the panels in the fact of movement. With air conditioned/heated spaces this is less of an issue that it once was, but still seasonal changes definitely affects hardwoods vs virtually inert (MDF). MDF will not move or relatively little with seasonal changes.

Hardwoods will move to a degree, some more some less. Some form on an unique plywood would be interesting, but hardwood plywoods are typically made of Birch or Maple, which tend to move too much (IMHO), if they were to be veneered. The bamboo LBL is interesting, due to its construction, but time will tell how it acts in a home environment and with seasonal changes.

Other than a synthetic substrate, I don't think that wood product that does everything exceptionally well is in existence right now, so we deal with what we have available.

A box needs to have a higher resonant characteristic, with great strength. If you have any ideas to improve the speaker box, I am all ears, but as a woodworker, the use of solid wood in a large box, makes me a little squeamish, to say the least. Now if we were to use all Mesquite for this box, then I am a little bit less worried about movement, as it is one of the most dimensionally stable woods on earth, but also difficult to find in large wide boards, as defects are very common in Mesquite. Plus it is incredibly beautiful to look at most of the time.

[dlr]

At Thiel they use a two or three story vertical column of cinder block/brick construction and have what looks like almost an airlock that they slide the speakers in on their backs lying in a padded cradle. The techs say you can't hardly stand up inside, the ear just goes nuts without input or reflection - sounds a bit apochryphal , but allows them a minimal footprint with an extremely strong structure and various measurement distances.

Their virtual tour seems unchanged. Too bad they don't have shots of the chamber. I'm trying to visualize how they cradle it without altering the response due to the cradle. Not a bad idea for efficient use of space. Better than the way that Dunlavy did it, a forklift to raise them 10' into the air for a horizontal oriented measurement.

The biggest problem with using all hardwood for the panels in the fact of movement. With air conditioned/heated spaces this is less of an issue that it once was, but still seasonal changes definitely affects hardwoods vs virtually inert (MDF). MDF will not move or relatively little with seasonal changes.

I always wonder just how much of a problem this might be in a typical home environment, especially with the widespread use of air conditioning.

Dave

[Johnloudb]

I always wonder just how much of a problem this might be in a typical home environment, especially with the widespread use of air conditioning.

Dave

One word - Swamp Coolers

One word - Furnace Humidifiers

One word - Lake/Ocean Front Property

Though, I've seen designs use all types of wood successfully. So, I don't think it is a huge problem. Just got to take everything into account in a particular design.

By the way, Your speaker is looking Awesome Jon. Don't know how you do it, as pushed for time as you are. :T

[bigg]

Yes, I just had to go find them again, but it's an MT, not an MTM. Could be changed into an MT, like the difference between a Modula MT and a NatalieP; which do you need?

Thanks Jon. The MT plans are great. I was going to build the MTMs with the HiVi D6.8s like another member I talked to.

NyxOne said he built the Modula MTMs with the HiVi D6.8s but that he needed the crossover design for that. I told him that I had already requested the plans from you and that you were going to get back to me at a later date. But I think he used the Seas tweeter. I was going to too. But since I have'nt bought the drivers yet, it's not a problem to go with the Vifas.

Thanks again, :thanku:
Gary

[JonMarsh]

I'd recommend going with the Seas- which one did you want to use? I can update this easily, as I have measured data for this configuration with several tweeters, can do the 27TBFCG, too. Just let me know which configuration(s) you need. The XT-25 is not a happy camper down low at higher volume- the 27TDFC or 27TBFCG are better choices. Now, if you want spend a teensy bit more money, I'd recommend the D2608/913000, the replacement for the Peerless HDS tweeter.

[bigg]

I'd recommend going with the Seas- which one did you want to use? I can update this easily, as I have measured data for this configuration with several tweeters, can do the 27TBFCG, too. Just let me know which configuration(s) you need. The XT-25 is not a happy camper down low at higher volume- the 27TDFC or 27TBFCG are better choices. Now, if you want spend a teensy bit more money, I'd recommend the D2608/913000, the replacement for the Peerless HDS tweeter.

Hi Jon,
It will be a little while before I get to that project but it's going to be my favorite. So I'll go with the Peerless. I checked Madisound it's $78.00 each right now. The cabinet work will be my most ambitious so far. It will be inspired by your Ardents and the Humble HomemadeHiFi Galactica. Of course it won't be exactly like either of those. I hope to go with some kind of composite front baffle and also incorporate some deep bevel cuts. Thank you,
Gary

[benchtester]

Jon,

Do you plan on bringing the Ardents to Burning Amp 2009?

http://home.comcast.net/~burningamp/Burnigamp2009/BurningAmp/index.html

It's on October 18 this year.

(Pretty Please)

[JonMarsh]

I'll be in Austria and Germany on business, meetings at our HQ and attending the International Conference of Silicon Carbide and Related Materials, so, I guess the answer is no- I've heard of this event but have never been to one.

It looks very cool- more's the shame!

[JonMarsh]

Proof I haven't just been goofing off..

Even with all the errands, have been making some progress- some I can talk about here (relevant).

This is the underside of a base assembly- the holes haven't been drilled for the connector bolts to fasten it to threaded inserts in the base- bolts will go through the 1-1/2" by 3/4" maaple that's on the inside. Points will be mounted at the front and back corners. The maple is epoxied to the MDF core of the base. Outside is fabricated from 2-1/2" by 3/4" maple.



Top side didn't look this clean until after sanding and getting rid of the last of the Titebond III bonding the outer maple and MDF.




Hope this counts with Chris as "finishing something" today!

[Hdale85]

Those look fantastic!

[Evil Twin]

Old man, I warn you that while the quality of work you are doing is at least adequate, the quantity leaves something to be desired.

Do not forget the Chancellor's schedule and expectations - RMAF is looming close, and he is not as forgiving as I am of your slow production efforts. Redouble them!

[Biff]

Their virtual tour seems unchanged. Too bad they don't have shots of the chamber. I'm trying to visualize how they cradle it without altering the response due to the cradle. Not a bad idea for efficient use of space. Better than the way that Dunlavy did it, a forklift to raise them 10' into the air for a horizontal oriented measurement.


I always wonder just how much of a problem this might be in a typical home environment, especially with the widespread use of air conditioning.

Dave

The cradle appeared (IIRC) to be a pair of Shaq's old slingshot handles, maybe half the width of a 3.7, wrapped in swaddling clothes. The rounded backs nestled therein.

[Deward Hastings]

Rather than analogize enclosures to musical instruments (which are deliberately resonant structures *intended* to color sound) we might analogize to loudspeaker cones . . . MDF is like paper, not “stiff” at audio frequencies but internally damped, while hardwoods are like metal, stiffer and with more pronounced resonances.

So I find myself thinking that the “ideal” box does not resonate. The “ideal” box does not radiate. The “ideal” backwave is completely absorbed (or completely free). *Any* box resonance, even those deliberately introduced by the designer, produces an output into the room that differs from the input signal.

If an enclosed speaker is mounted on an infinite baffle (in the plane of the loudspeaker baffle) what do you hear (measure) on the back side? It almost has to be totally “distortion” relative to the input or the front side radiation, doesn’t it?

Despite well documented frame resonances and the direct transfer of energy to the baffle and box (which must then be made massive in response) we still see almost universal mounting of drivers at the basket rather than at the motor. Why?

[JonMarsh]

Despite well documented frame resonances and the direct transfer of energy to the baffle and box (which must then be made massive in response) we still see almost universal mounting of drivers at the basket rather than at the motor. Why?

Inertia, habit, and manufacturing styles. Some driver frames are short and stiff enough that they contibute minimal resonance (Accuton C79 comes to mind), but Accuton uses a rear brace and damping pad to futher deal with that resonance.

Sigfriend Linkwitz is just a bit ahead of many of his contemporaries- and if you've heard Orions, and heard much of what is considered high end at CES, well, a lot of things become clear. Unfortunately, some aspects of driver design are rather at odds with each other. The SS illuminator have gone all out to minimize rear masking, and have done a pretty good job of stiffening up the frame, too. Now if they only offered a series of drivers with dampened ceramic cones, I'd be in heaven.

[Dennis H]

I meant to reply to this earlier but I forgot.

An impulse response will show all resonances or lack thereof and the wideband response. Yet I have never seen such. All I hear is conjecture on both sides. If mdf absorbs too much, it will show. If hard wood does not and is stiff enough, the resonances will be that of the driver alone. Use the same driver, normalize to a reference you have the material signature. Normalize one response to another and voila, pure objective evidence for absolute difference of materials.

I think, rather than trying to pick up cabinet resonances with a mic, and separate them from what the driver is doing, it makes much more sense to measure the cabinet directly with an accelerometer. JA does some of that in his Stereophile measurements. You can buy an accelerometer for a reasonable price from Digikey and use it just like a mic in your measurement system.

http://www.libinst.com/accel.htm

[JonMarsh]

Agreed and planned. :W

Did this a long time ago, too, which is what resulted in my first Avalon style cabinets in the 70's- ones given to Charles Hansen when my new wife wouldn't "allow" me to keep them.

[dlr]

I meant to reply to this earlier but I forgot.
I think, rather than trying to pick up cabinet resonances with a mic, and separate them from what the driver is doing, it makes much more sense to measure the cabinet directly with an accelerometer. JA does some of that in his Stereophile measurements. You can buy an accelerometer for a reasonable price from Digikey and use it just like a mic in your measurement system.

http://www.libinst.com/accel.htm

I've got one. Got it when Bill Waslo (Liberty Instruments for those who don't know) recommended it to us when briefly posting on the Madisound board, many years ago.

It is not an exceptionally accurate way to depict any form of absolute with regard to box panel resonances, let alone audibility of such. It's not calibratable for the acoustic response since that would have to be an integrated measurement of all surface areas of the box, results cannot be translated into the acoustic domain for that same reason and others and is subject to widely varying response due to method of attachment.

It's great for identifying that specific resonances exist and relative amplitude at any individual point on a baffle, but that's close to the extent of it. It's no different than identifying resonances at specific points on a diaphragm. Move slightly and the wide band response can be so different that peaks can become nulls and vice-versa. A few individual points are useless, only the integrated response matters.

In the end, the only thing that matters is what happens in the acoustic domain in the air. That is measurable by calibrated mics now with no question as to reliability if done by someone with competence to do so. If the box material does not significantly alter the acoustic response, what's the issue? Any box resonances that emit sound would simply fall into the category of linear distortion for the most part. If SPL and distortion measurements did not pick it up or show it to be insignificant, it's moot.

Dave

[JoshK]

Getting the specific thicknesses I wanted was a bit of a pain, given my limited storage and purchasing resources, and that I can't manhandle 4' X 8' sheets by myself. This project was built with starting from pre-cut 2' X 4' stock, from HD. You have to be careful buying from HD; there's variability in quality; fortunately I had a lot of the 1/4" bought previously, and their current 3/4" at my local stores is OK.

The side panels are made from 3/4 + 1/4 laminated on both sides- you must do that to prevent warping, just as with veneering. That gives the desired 1-1/4" thick sides and back. The top front panel layer is 1/4" MDF + 3/4" LBL + 1/4" MDF, for 1-1/4" total; the second and third layers are 1-1/2" by combining two 3/4" layers. Top is also 1-1/4", three layer lay-up. Titebond III was used for the panel lay up.

Isn't Titebond III Polyurethane? I never could manage to do nice work with it. It expands all over the place and oozes out the sides and leaves a giant mess. How do you work with it?

Your using it between layers in your baffles? Do you flish trim the sides after your done to clean it up?

[JonMarsh]

It's not polyurethane; you may be confusing it with the glues that are activated by water and tend to foam up, I can't remember the type off hand. Titebond three behaves similarly to Titebond II as regards application and handling, but it doesn't shrink much when drying and it is completely water proof, and harder when setup. I wipe things down a couple of times after clamping, and generally do rough cuts through the saw to the approaximate size before a finish cut to exact dimension.

[Curly Woods]

It's not polyurethane; you may be confusing it with the glues that are activated by water and tend to foam up, I can't remember the type off hand. Titebond three behaves similarly to Titebond II as regards application and handling, but it doesn't shrink much when drying and it is completely water proof, and harder when setup. I wipe things down a couple of times after clamping, and generally do rough cuts through the saw to the approaximate size before a finish cut to exact dimension.

Titebond III glue is a Proprietary Polymer while Titebond II is a PVA (polyvinyl-acetate) type. Gorilla Glue and their sort are polyureathane types that are activated with water.

http://www.titebond.com/download/pdf/ww/GlueGuideTB.pdf

[JoshK]

Thanks. For some reason I thought TBIII was a PU like Gorilla Glue. I hate GG from my brief experience with it. The foaming up made a mess as it oozed out of all the seams.

[Curly Woods]

Thanks. For some reason I thought TBIII was a PU like Gorilla Glue. I hate GG from my brief experience with it. The foaming up made a mess as it oozed out of all the seams.

It is great to fill those less than perfect miter joints and other squiggly seams :-)

[JonMarsh]

Thanks for filling in the gaps in my memory Curly! Obviously, everything has it's place and time and use...

[JonMarsh]

It is great to fill those less than perfect miter joints and other squiggly seams :-)

C'mon now, Mike- no one at this forum would ever have less than perfect miter joints or squiggly seams! That would be such unseamingly behavior!

[Curly Woods]

C'mon now, Mike- no one at this forum would ever have less than perfect miter joints or squiggly seams! That would be such unseamingly behavior!

:rofl:

[JonMarsh]

Late breaking update...

New acoustic Jazz album in house...




Yes, it's the Hiromi + Stanley + Lenny channel, bound to be a new favorite, based on the first few tracks. Ensemble playing, so far, subtle, not just a flash showcase. I like it... very much in a traditional acoustic jazz playing- interesting to hear this kind of playing from them.

[Dennis H]

Wow, very different stuff from the godfather of electric slap bass.

[Paul Ebert]

Interesting. I see it's also available in vinyl. I wonder how that sounds...

[Hdale85]

I bet it sounds fantastic with that new DAC too I'm going to have to pick this one up.

[JonMarsh]

Interesting. I see it's also available in vinyl. I wonder how that sounds...

Actually, it was issued in vinyl before the CD- I think it's a new label setup under Concord music by Clarke.

[PhilDSP]

Interesting... How is the quality of vinyl these days? From my old LP collection I'd say that 60% to 70% of the albums were hopelessly tainted with snap, crackle and pops that came not from being dirty but from either a poor pressing or poor material I'd guess.

My expensive DVD Audio player got knocked out by lightning this summer (it wasn't even plugged in) and I had to listen to a cassette player with lots of recorded LP's. My favorites for audio quality were commercial cassettes because of the LP noise. But I was surprised at how very pleasing the general audio quality was on both cassettes and cassette duped LP's.

[JonMarsh]

Vinyl is pretty much only issued for the "premium" market these days, boomers with bucks, and younger folks who have discovered it- while CD is free of the ticks, pops, and rumbles, it has had other problems, as I rant about in this thread about:

Bday thread

and there are some areas the quality of digital reproduction is just catching up to good vinyl in the late 70's, IMO. Which has been frustrating for me, as I did jump to digital pretty quickly, and have missed some things since then. I haven't missed the typical ticks and pops and inner groove distortion (unless the record was cut with minimum time expectations and maximum groove width).

We've been a victim of some subtle but serious phase/time distortions all these years.