My Modula MT’s are done. Impressions and many pics

[JonW]

I'll be interested to hear your results because I don't think a lack of sparkle was holding the Modulas back after that resistor mod. It was the slight echoey sound of the Modulas (only reveals itself when directly compared) and the overall better tone of the Totems.

I’m curious as well. I agree that the less smooth presentation was holding them back relative to the Totems. But I can only say such a thing after the resistor mod because that fixed the single biggest thing I didn't like. The biggest difference is gone and now we're at smaller things.

I am not putting my impressions in here about the difference so as to

Fair ‘nuf.

Yes, yes, if you stop by, I will not only be able to let you listen to the 3910, but also its little cousin so that you can determine if there is a difference in sound between a less expensive universal player and a more expensive one. Plus you will get to hear an SACD! :T

Excellent. I’ll have to give you a ring to get your address, schedule, and such. The drive to Florida is looking very likely at this point. Maybe a little hiking in the Smoky Mountains on the way. And then a little scuba diving in the Keys… Ah…

[Dennis H]

It was the slight echoey sound of the Modulas

Time to tweak the stuffing?

[JonW]

Time to tweak the stuffing?

OK. Got any recommendations of what to try?

Right now, I’ve got 2 layers of poly batting on the left and right walls, except for where one of the small xover boards goes. Some pics here:

Image not available

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[soho54]

None on the back?

[chasw98]

Go to Wal Mart and buy a bag of poly fill and loosely stuff the cabinet for testing.

[Dennis H]

JonMarsh uses Whispermat on all the walls, thick stuff on the back, thin stuff on the sides, top, bottom. PE sonic barrier is about the same thing. He also folds layers of poly quilt batting so he has a wad 3-4" thick and stuffs it behind the mid about halfway back. Make sure you don't block the airpath between the mid and the port. As an experiment, stuff the bottom rear quarter of the enclosure with whatever is handy. It's really important to keep the midrange from bouncing off the back wall and back out through the cone.

https://www.htguide.com/forum/search.php?searchid=486165

http://www.partsexpress.com/webpage.cfm?webpage_id=3&CATID=29&ObjectGroup_ID=1 37&filter=sonic&raid=44&rak=sonic_barrier

[ThomasW]

HEY!, HEY!, HEY!, that's super dooper top secret, proprietary information.....let's not be telling the entire world..... :naughty: :B

[Dennis H]

Dang, sorry. Good thing it's JonMarsh's secrets I'm giving away. I hate to think what Evil Twin would do to me.

[Evil Twin]

Well, well, what do we have here, some Bothan rebel spies? The Emperor would be most unhappy to find Imperial secrets posted on the hypernet... fortunately for you, even HIS force choke hold is not effective across oceanic distances, much less mine.

In this case, though, we must commend your forthcoming attitude to supply information to aid those who don't read the construction posts thoroughly... some of us do not have similar patience with the rebel constructors. Of course, if those pathetic excuses for moderators kept the rabble on topic in the key threads, there wouldn't be such lengthy postings to wade through to find the scant nuggets of useful data available here...

[JonW]

No, it doesn’t have any poly on the back. I’ll try stuffing it loosely with a bunch of poly batting- I’ve already got it around. And see if that helps.

HEY!, HEY!, HEY!, that's super dooper top secret, proprietary information.....let's not be telling the entire world..... :naughty: :B

Yep. Hiding in plain site. Nobody believes all that junk out there on the web. So the secret is safe with us.

Well, well, what do we have here, some Bothan rebel spies?

:rofl:


Actually, months back before I started making these speakers, I read every post available (here and elsewhere) on Whispermat- because Jon mentioned he likes it. Maybe it’s time to place an order.

[JonW]

A quick update:

I jammed a bunch of poly batting into the speakers. Sure enough, they sound better. Thanks folks! :T

The difference is definitely not as pronounced as the resistor change, but it is, indeed, a little nicer. I started out by stuffing only one speaker, then moving left and right. The stuffed speaker just sounds a little smoother. Once again, I asked my gal for her opinion without telling her what I did (lucky for me she also finds this interesting). She picked out the stuffed speaker as sounding better.

No loss in detail, yet things blended together better. (Such words seem contradictory to me, so maybe my description is not great.) Now they're both stuffed. I started changing the resistor values from the current 4 ohms down to 3.3 to see if the added smoothness would then require a bump up in the tweeter level to bring out more perceived clarity and detail. I didn't have enough time to really test that- more to come soon. But from a very quick impression, the 4 ohms may still be the way to go.

[cgr]

For thowing things together quickly, the active is the winner - because it is clearer. The mid-range on the passive is somewhat muffled by comparison. Either of them make a PSB bookshelf (had one handy) sound pretty poor by comparison.

I'll be listening to and testing both active and passive over the next little while. If I get any worthwhile info I'll start another thread and post it.

Given that the price of a CX2310 is about the price of a pair of the large inductors for a Modula MT - What, if any are the disadvantages to using an active crossover instead of a passive one in an application like this?

[Dennis H]

The CX2310 can't do baffle step compensation, notch filters for cone resonances, adjust for the drivers' actual response, etc. If you want to go active, using real drivers in real boxes, you need a custom crossover. You can do it with custom analog filters built with opamps, resistors and caps or with a digital box that lets you use a DSP to customize the response. Either way, there's just as much 'art' involved designing an active crossover as designing a passive crossover, just a different set of tools.

[Paul H]

The CX2310 can't do baffle step compensation, notch filters for cone resonances, adjust for the drivers' actual response, etc. If you want to go active, using real drivers in real boxes, you need a custom crossover. You can do it with custom analog filters built with opamps, resistors and caps or with a digital box that lets you use a DSP to customize the response. Either way, there's just as much 'art' involved designing an active crossover as designing a passive crossover, just a different set of tools.

Absolutely right Dennis (as usual). I've actually been thinking about building a custom crossover using the CX2310 as a chassis and adding in baffle step, notch filter, etc as required. Given the relatively cheap price of the CX2310 and the fairly clean filters it should work. Anyone tried that, any problems with that approach?

[---k---]

John,

Great news! Now you need to bring them back up here for me to listen too.


How did the listening test with the Seas version go? Have you done it yet?

[JonW]

How did the listening test with the Seas version go? Have you done it yet?

It's scheduled for tomorrow.

[cobbpa]

Me & Jon compared Modulas Tuesday. To be fair to the ones I brought, they were built with some different goals in mind. But long story short, I don't think they were what Jon was looking for. As you can see in the picture, my are a smaller sealed design as they will be used for 6th & 7th channels in a home theater. There was no stuffing in them yet and and were not broken in at all. Jon's sounded better to me for most daily listening. I did prefer the Seas tweeter on some tracks (Eva Cassidy) but on others is just stood out too much. They were very forward, which sometimes translated to harsh and sometimes that nice "front row" feeling. The tweeter was definitely what drove the speaker. I'm not sure how much of that is the box (F3 of 75ish hz) or lack of stuffing stuffing or newness of the driver, but the midrange detail was lacking. If it had been there, the Seas version definitely would have benefitted.

Jon showed me the results of switching around resistors in his RS Modulas. Cool to hear the differences it makes. I do like the value he has mostly settled on (can't remember the exact number). When it was the higher (original) value, some high-end details just weren't there. I remember this with the rain in the beginning Jack Jonson's Banana Pancakes. My Seas version played it very pronounced, Jon's tweaked version played it audibly but not as loudly, and the original value made it very hard to hear it.

It was a very fun afternoon, cool to meet & talk to Jon, hear some different music and compare speakers. Honestly, the Totems were definitely the best pair in the room and my Seas version the worst for daily music listening, I'm sure. They'll accomplish their surround task well, but I'd prefer Jon's altered version to hear as mains every day. Thanks again Jon, I'd like to do it again if you get into building your own :T !

[chasw98]

Very interesting. Jon is thinking of coming to Florida and stopping by to meet/see me. I wonder what it would take to get him to put his M/T's in the car and bring them with him to compare against my M/T's with the Seas in them that have stuffing and were built the same size........... BTW, I use mine for surround duty as well. Hmmm, I will have to ask him and see if it is possible. (Besides I want to see the finish on his :T ).

Chuck

[dlneubec]

There looks to be a lot of hard reflective surfaces in that room, which may have brightened up your seas version a bit also. However, it seems like HT has the highs augmented more than music.

Also, I wonder if the alligator clips and leads that allows Jon uses to switch resistors outside the box might add resistance to the tweeter circuit that would not exist with the resistor wired directly, making the original design sound even more laid back than normal.

[---k---]

Very interesting. I bet it was a great time.

Not what I was expecting. Though, as Jon found out, the stuffing can make a difference. Also what is the deal with the clamps? Is it the front or back not glued on yet?

It would be great to redo this test in a few months when you have finished them off.


(also, if you could resize your pictures to avoid side-to-side scrolling, it would be appreciated.)

[---k---]

There looks to be a lot of hard reflective surfaces in that room, which may have brightened up your seas version a bit also. However, it seems like HT has the highs augmented more than music.

???
Didn't you see that they attached a yellow peice of paper to the blinds behind the speakers to take care of this. That should have made the room perfect! :rofl:

[JonW]

Hey Phillip-

Very nice to meet you and thanks for coming over. It’s always great to meet someone from the board and hear another pair of speakers.

So Phillip’s speakers sounded *very* different from mine. His tweeter seemed a little too strong to my tastes. If this helps calibrate anyone, when I bypass the 5 ohm R3 of my speakers, the tweeter is not running as hot as Phillip’s was. I wonder why, though. His speakers are smaller volume, sealed, different tweeter and xover. So I guess it must be those things.



Chuck-
Sorry, but I can’t bring the speakers down there. The car will be quite full with all our dive gear. And if I get to dive rather than compare the speakers… well, I won’t complain one bit.

[JonW]

There looks to be a lot of hard reflective surfaces in that room, which may have brightened up your seas version a bit also.

Yup. If you see the first photo in this thread you can see a couple fiberglass panels I made, hanging on the wall. I’ve got to make some more, but I’ve been distracted by building speakers.

???
Didn't you see that they attached a yellow peice of paper to the blinds behind the speakers to take care of this. That should have made the room perfect! :rofl:

The note is there to remind the painter not pull up the blinds because they won’t ever go back down again. He’s got to fix that window that he broke. But you’re right. The acoustic benefits are such that I may soon be putting paper over all my windows. (And aluminum foil on my head.)

Also, I wonder if the alligator clips and leads that allows Jon uses to switch resistors outside the box might add resistance to the tweeter circuit that would not exist with the resistor wired directly, making the original design sound even more laid back than normal.

Do you think? Interesting. So maybe all my testing between resistors of different values still won’t turn out exactly right. Uh oh. Oh well.

[chasw98]

Do you think? Interesting. So maybe all my testing between resistors of different values still won’t turn out exactly right. Uh oh. Oh well.

Just use your new meter to measure the total resistance of the external resistor and the alligator clip leads once you find the value you like and then use a resistor of that value!

If you can't bring the speakers then just make sure the last thing you do before you leave is listen to them and then run to the car and drive south. That way the memory of your sound will be fresh in your aluminum wrapped head! :rofl:

Chuck

[Jim Holtz]

Me & Jon compared Modulas Tuesday. To be fair to the ones I brought, they were built with some different goals in mind. But long story short, I don't think they were what Jon was looking for. As you can see in the picture, my are a smaller sealed design as they will be used for 6th & 7th channels in a home theater. There was no stuffing in them yet and and were not broken in at all. Jon's sounded better to me for most daily listening. I did prefer the Seas tweeter on some tracks (Eva Cassidy) but on others is just stood out too much. They were very forward, which sometimes translated to harsh and sometimes that nice "front row" feeling. The tweeter was definitely what drove the speaker. I'm not sure how much of that is the box (F3 of 75ish hz) or lack of stuffing stuffing or newness of the driver, but the midrange detail was lacking. If it had been there, the Seas version definitely would have benefitted.

Jon showed me the results of switching around resistors in his RS Modulas. Cool to hear the differences it makes. I do like the value he has mostly settled on (can't remember the exact number). When it was the higher (original) value, some high-end details just weren't there. I remember this with the rain in the beginning Jack Jonson's Banana Pancakes. My Seas version played it very pronounced, Jon's tweaked version played it audibly but not as loudly, and the original value made it very hard to hear it.

It was a very fun afternoon, cool to meet & talk to Jon, hear some different music and compare speakers. Honestly, the Totems were definitely the best pair in the room and my Seas version the worst for daily music listening, I'm sure. They'll accomplish their surround task well, but I'd prefer Jon's altered version to hear as mains every day. Thanks again Jon, I'd like to do it again if you get into building your own :T !

Are these the no BSC version by any chance? What you are describing would follow with lack of BSC.

Jim

[cobbpa]

Are these the no BSC version by any chance? What you are describing would follow with lack of BSC.

Jim

No, these are the regular ones..haven't built the non-BSC ones yet.

The clamps are there because the baffles weren't glued on yet. I had to spend a little time doing some makeshift assembly

I would like to listen to them again once completed as well, but I doubt it happens..my uncle's room is coming together pretty quickly. As Jon said, they were both very different speakers..enough to really make me think it was more than just the tweeter. I'm hoping foam, stuffing, and breaking in the woofer helps even them out.

My bad on the big pictures..on my widescreen they fit nicely. I'll do them differently here on, thanks for the heads up!

An edit to note: I don't want to seem as though I am displeased with the speakers I have built. Rather, I'm hoping to express how differently mine & Jon's sounded. I do hope what I have left to do flattens them out some, but for my purposes, not too much. They will be hanging from the ceiling and near a sidewall as well. There will be a lot of heavy dialogue use (i.e., football broadcasts) where it seems a touch on the 'bright' side would keep things clearer than the other way. These will definitely do well for their tasks as needed, but I would prefer Jon's as every day music speakers.

[SteveCallas]

Somewhat related, I have heard people say that poly woofers don't or can't offer as much detail as metal....I don't know if the Modula MT is the best example, but the Totem offers at least as much detail. Rather than generalize by cone material, I think it again, as seems to always be the case, comes down to implementation.

[ThomasW]

Here's the deal with cone materials. The 'ideal' cone has 'pure' pistonic (aka linear) motion. No cone has pure linear motion throughout it's passband. This means all cones have breakup modes.

The metal cones offer the most linear performance up to their first breakup mode, then they go 'nuts'. That's why Jon designs with his CE filters that have 48dB slopes. And uses very low XO points to avoid having any of the nasty stuff from the breakup polute the sound.

Poly cones are the least rigid = least linear. But when they break up doesn't sound as nasty as the more rigid technologies.

So poly cones are inherently 'more forgiving', but that characteristic means they're less detailed. If this isn't audible in someone's system, it's a reflection of the gear in the signal path.

When someone characterizes metal cones as 'hot', 'harsh' or whatever, this is either a function of a poorly designed crossover, or the cone reproducing issues with gear in it's signal path.

Now I'm sure there are people that will disagree with this, but it's my story and I'm sticking to it.... :B

JonW is coming out to Denver in a few weeks, I'm tempted to whip up a pair of JonMarsh's box speakers. Then JonW can hear a $400 speaker driven by a system with nothing but Ayre Acoustics gear after the DAC. Oops I suppose that's 'cheating'.... :W

[ssabripo]

....can hear a $400 speaker driven by a system with nothing but Ayre Acoustics gear after the DAC. Oops I suppose that's 'cheating'.... :W

what?! you mean no Denon or Yamaha driving this stuff? meh...

:rofl:

[philip_g]

what?! you mean no Denon or Yamaha driving this stuff? meh...

:rofl:

eeee

[JonW]

Just use your new meter to measure the total resistance of the external resistor and the alligator clip leads once you find the value you like and then use a resistor of that value!

No problem. Will there actually be much of a significant, measurable difference? I wouldn’t have guessed so, but I’ll have a look and find out.

If you can't bring the speakers then just make sure the last thing you do before you leave is listen to them and then run to the car and drive south. That way the memory of your sound will be fresh in your aluminum wrapped head! :rofl:

I’m on it!!! :

[JonW]

JonW is coming out to Denver in a few weeks, I'm tempted to whip up a pair of JonMarsh's box speakers. Then JonW can hear a $400 speaker driven by a system with nothing but Ayre Acoustics gear after the DAC. Oops I suppose that's 'cheating'.... :W

Oooooooo... don't think I've heard any of that before. :drool:
Don't go to any extra effort on my part. I suspect that you already have enough audio toys to make anyone here jealous. I'm looking forward to it. :B

[chasw98]

JonW is coming out to Denver in a few weeks, I'm tempted to whip up a pair of JonMarsh's box speakers. Then JonW can hear a $400 speaker driven by a system with nothing but Ayre Acoustics gear after the DAC. Oops I suppose that's 'cheating'.... :W

So Jon, here you are in Indiana (wherever that is :P) and you are going to see your "dealer" in Florida and then you are going to go to Denver to score some more from the dealer out there. We own you. Why don't you just start making monthly deposits to our accounts and we will get you what you need! :T

Chuck

[philip_g]

Oooooooo... don't think I've heard any of that before. :drool:
Don't go to any extra effort on my part. I suspect that you already have enough audio toys to make anyone here jealous. I'm looking forward to it. :B

He does.

[JonW]

So Jon, here you are in Indiana (wherever that is :P) and you are going to see your "dealer" in Florida and then you are going to go to Denver to score some more from the dealer out there. We own you. Why don't you just start making monthly deposits to our accounts and we will get you what you need! :T

Chuck

But the kind gentleman on the corner said the first one would be free. :

[---k---]

Funny stuff.

I'm really starting to get jealous of Jon and his adventures coming up.

[SteveCallas]

So poly cones are inherently 'more forgiving', but that characteristic means they're less detailed

Well again, wouldn't this just come down to how the design handles the higher frequencies? Can you define "detail" solely by breakup characteristics? I see a LOT of variation in higher order distortion harmonics form Zaph's latest round of testing - I'd have to imagine that would play a signifcant role, as FR can be altered in the crossover.

system with nothing but Ayre Acoustics gear after the DAC. Oops I suppose that's 'cheating'....

I'd love to do some blind testing of your type of 'cheating'

[JonW]

Funny stuff.

I'm really starting to get jealous of Jon and his adventures coming up.

Jealous? Did you say jealous? I have to hang out with Chuck. Obviously I did something very bad in a past life. :

[ThomasW]

Well again, wouldn't this just come down to how the design handles the higher frequencies?

It's not simply limited to the reproduction of HF. It's how accurately it reproduces all program material in the passband.

Can you define "detail" solely by breakup characteristics?

Linear cone motion indicates how accurately a driver reproduces a given signal. That accuracy is what determines the 'detail', the SQ

I see a LOT of variation in higher order distortion harmonics form Zaph's latest round of testing - I'd have to imagine that would play a signifcant role, as FR can be altered in the crossover.

Low distortion is always a good thing. Distortion is a function of the design of the motor, suspension and the cone. The only 'altering' effects a crossover has on FR is to attenuate it, unless we're talking about all-pass designs

If you haven't done so, download and read Jon's AudioXpress article, it's virtually a treatise on loudspeaker design.

http://homepage.mac.com/jonmarkhancock/.Public/M8_PublicationMkIV.pdf

[---k---]

Thomas,

Something that always makes me go huh, but seems like is accepted by people around different parts, let me ask you and for once get a definitive answer:

Only considering playing at moderate levels, where non-linearities aren't a concern.
If two different drivers have the same frequency response over a given range, will they sound the same over that same range? Iow, is frequency response the only thing that makes up how something sounds, or is there more too it than that.

[---k---]

Jealous? Did you say jealous? I have to hang out with Chuck. Obviously I did something very bad in a past life. :

I was mainly thinking about Denver.

[chasw98]

Hey, you guys let me know when I should start developing a complex, OK?

[ThomasW]

Thomas,

Something that always makes me go huh, but seems like is accepted by people around different parts, let me ask you and for once get a definitive answer:

Only considering playing at moderate levels, where non-linearities aren't a concern.
If two different drivers have the same frequency response over a given range, will they sound the same over that same range? Iow, is frequency response the only thing that makes up how something sounds, or is there more too it than that.

FR is important, but it's only one piece of the puzzle.

If one takes two loudspeaker of different designs, construction or whatever, and EQs them to the same FR, they will sound very 'similar', but they won't sound identical.

My guess is that someday we'll have powerful enough computer processing; we'll be able to analyze almost every performace characteristic of any given design, then create 'model' or 'signature' based on that data. One would then apply that model to other designs and virtually replicate the original.

This would be a more sophisticated version of what Bob Carver did a decade or so ago, when he 'tweaked' the transfer functions, and voiced a solid state amp so it sounded like a tube amp.

[---k---]

Jon,
I beleive I saw a recent post from you, so I assume you are back in the land of corn and Subarus. So what did you think of Chuck's speakers? I'm looking for a full report to tempt me even further.

[chasw98]

Yeah, Jon? We are waiting to hear you're impressions and Gudrun's impressions also!

Chuck