Observations / questions from a n00b

[rumatt]

I've been lurking in DIY forums for a few weeks now. This looks like a fun hobby and it's only a matter of time before I build myself some kind of speaker.

But a few trends stand out in the popular designs that I don't understand.

1) Why is the MTM design so popular for mains? Why not TMM, or even TMW? Is the tweeter on top a thing of the past? I guess TMW would require a 3 way crossover, so that is more complex.

2) Why don't more people experiment with active crossovers, and biamping? Some (crazy?) people buy commercial speakers, rip the crossovers out, and replace them with active crossovers + biamping. If you're designing the speakers and crossover from scratch, it seems like a good opportunity to go with active. It would also be easier to experiment with different crossovers as they don't need to be inside the speaker.

3) The hardest thing about DIY for me is not the time and effort involved, but the idea that you have no idea what it will sound like until you're done. It must be frustrating to build something and then not like it better than what you already had. Even over-simplified comparisons to commercial speakers are rare. I currently have Paradigm Studio 60 mains, and Studio CC center (V2). Has anyone compared any of the common designs here to these speakers? Has anyone done a DIY speaker setup and gone back to their original setup?

If I build anything I would want to ensure an improvement, and would probably lean toward the higher end options. However, I don't listen at particularly high volumes and I don't need huge speakers, so maybe something like the Modula MTM would be for me. But how could I not upgrade to the TMWW???? :B

[jonathanb3478]

[QUOTE=rumatt]

1) Why is the MTM design so popular for mains? Why not TMM, or even TMW? Is the tweeter on top a thing of the past? I guess TMW would require a 3 way crossover, so that is more complex.

Well, I would say that I prefer a TMM to an MTM. For a TMM to work, you need to make it 2.5-way, I believe. So, there is your answer. You touched on it already, actually. 2-way crossovers are cheaper than 2.5-way are cheaper than 3-way.

Maybe there is more to it than that, I do not know.

2) Why don't more people experiment with active crossovers, and biamping? Some (crazy?) people buy commercial speakers, rip the crossovers out, and replace them with active crossovers + biamping. If you're designing the speakers and crossover from scratch, it seems like a good opportunity to go with active. It would also be easier to experiment with different crossovers as they don't need to be inside the speaker.

Well, I know that people use active crossovers here. I would say that if MTMs are popular due to cost issues, passive crossovers are even more disproportionately represented due the the more extreme increase in cost experienced when implementing active crossovers vs passive. You need to purchase a 3-way stereo capable active crossover unit and 6-channels of amplification to make an active 3-way. That is cost prohibitive for many, I think.

3) The hardest thing about DIY for me is not the time and effort involved, but the idea that you have no idea what it will sound like until you're done. It must be frustrating to build something and then not like it better than what you already had. Even over-simplified comparisons to commercial speakers are rare. I currently have Paradigm Studio 60 mains, and Studio CC center (V2). Has anyone compared any of the common designs here to these speakers? Has anyone done a DIY speaker setup and gone back to their original setup?

I wouldn't say you have no idea. You have people who state what they have and what they built and what they think of the new project. That is in no way the same as hearing it for yourself, but it is far from "no idea", too.

I have not heard of people going back to their old speakers after finishing a DIY project. I will say there are people that would have, after hearing the new DIY speakers for the first time. Those people worked with the crossover designer to get "voicing" options for the crossover to correct for their preference. This is one of the truly great aspects of good DIY projects (every one on this site, for instance ), in my opinion.

If I build anything I would want to ensure an improvement, and would probably lean toward the higher end options. However, I don't listen at particularly high volumes and I don't need huge speakers, so maybe something like the Modula MTM would be for me. But how could I not upgrade to the TMWW???? :B

How indeed!

I believe there is a more costly crossover option for the RS TMWW project. Perhaps you should give that a try? :twisted:

[BobEllis]

I've been lurking in DIY forums for a few weeks now. This looks like a fun hobby and it's only a matter of time before I build myself some kind of speaker.

But a few trends stand out in the popular designs that I don't understand.

1) Why is the MTM design so popular for mains? Why not TMM, or even TMW? Is the tweeter on top a thing of the past? I guess TMW would require a 3 way crossover, so that is more complex.

Jonathan nailed it - a TMM needs to be a 2.5 way (unless you have an unusual tweeter that can be crossed in very low). AN MTM has certain pattern control benefits. It also gives more cone area for bass output without the beaming you would find in a larger woofer.

2) Why don't more people experiment with active crossovers, and biamping? Some (crazy?) people buy commercial speakers, rip the crossovers out, and replace them with active crossovers + biamping. If you're designing the speakers and crossover from scratch, it seems like a good opportunity to go with active. It would also be easier to experiment with different crossovers as they don't need to be inside the speaker.

I wholeheartedly agree. I've been singing the active song for years.

However, if money is an issue, getting started in active systems is a big step. You'll need extra amplification. Another issue is powerful low cost software for simulation. It doesn't exist, like there is for passive crossover design. So, unless you've got an easily adjustable active crossover (and not just a dial-a-frequency type), there's a lot of work. Many here seem to be uncomfortable enough soldering large components, much less opamps.

Additionally, most of the posters here are eager to build something that works, and lack the ability to properly design it themselves. Nothing wrong with that, just stating that there are only a few who have the requisite skills and equipment. Most of those either passive for their own reasons and/or publish passive designs because that is what most want.

3) The hardest thing about DIY for me is not the time and effort involved, but the idea that you have no idea what it will sound like until you're done. It must be frustrating to build something and then not like it better than what you already had. Even over-simplified comparisons to commercial speakers are rare. I currently have Paradigm Studio 60 mains, and Studio CC center (V2). Has anyone compared any of the common designs here to these speakers? Has anyone done a DIY speaker setup and gone back to their original setup?

If I build anything I would want to ensure an improvement, and would probably lean toward the higher end options. However, I don't listen at particularly high volumes and I don't need huge speakers, so maybe something like the Modula MTM would be for me. But how could I not upgrade to the TMWW???? :B

For me the journey is the fun part of this hobby. What works, what doesn't? As you gain experience you will likely find your missteps are fewer and further between.

You cannot go wrong with any of the mission accomplished designs here. I built Natalie P's for a friend. Within their limits (not quite full range, they need a sub) they will blow away anything you'll find in a big box store and match or beat most of the stuff you'll find in a midfi chain store such as the one named after a high frequency driver. Not the direct comparison you were hoping for, but it should give you a flavor.

I built the Nat-Ps in a 2.2 cubic foot MLTL (Mass Loaded Transmission Line) tuned to ~32 Hz. In a moderately sized room they give extension down to the low 30s. Not quite as effortlessly as the TMWW towers will, but they have a bit smaller footprint. If you use a sub or two the MLTL is overkill.

[cjd]

1) Why is the MTM design so popular for mains? Why not TMM, or even TMW? Is the tweeter on top a thing of the past? I guess TMW would require a 3 way crossover, so that is more complex.

'cause they do. Lobing behavior, and as mentioned, it simplifies some center to center issues that suggest a TMM really should be a 2.5 way.

2) Why don't more people experiment with active crossovers, and biamping?

Well, you're really asking two questions here. Active crossovers, for me is twofold: sound quality, and availability of good tools for simulating. It is also more easily shared, such that others can build.

Bi-amping, you could do passive quite as easily as actively. But there's a cost hit to do so. And there is the additional need to level balance with the potential for that to wander. In the end, the potential benefits are far outweighed by the negatives.

3) Has anyone compared any of the common designs here to these speakers? Has anyone done a DIY speaker setup and gone back to their original setup?

Well, I've compared my MTM's directly with a few, including Ascend 340SE's, Paradigm Studio 40's, a small Dynaudio TM (forget what). I've not compared the big WWMTM's because, well... that's pretty hard to do, they're so big! Paradigms grate on my ears and make me run crying from the pain. Fairly mellow and rounded midrange, very nice, though I really had a hard time analysing because the tweeter was so hot and so harsh. The Dynaudio's were nice, though they seemed a bit compressed. The Ascends had a nice sound also, though I think suffer from a crossover point that is too high and too shallow. I (and the others present) preferred my MTM. They're half the price of the Ascends, roughly, and 1/3 or less of the Dynaudio's and Paradigms.

The key for me was going out and attending some DIY events, some listening around, and paying attention to what I liked in sound, what types of designs sounded good to me. I spend a TON of time looking at data, really trying to understand what goes into all this. It's not really simple, though on the surface it can be. Ultimately though, a good crossover can make even mediocre drivers sound good. A few years ago at a DIY event, I brought along a pair of open baffle experiments that ran me ~$10 total. They had a magic to their sound and were the point of comparison far into the listening (we went from least expensive to most expensive).

One other thing to note: especially switching from speakers as oddly tilted in response as Paradigm, your ears WILL find any balanced DIY design to be a bit off. Your ears get quite used to a sound. I think there's a thread here about someone that at first found his Natalie P's to be lacking - perfect example.

If I build anything I would want to ensure an improvement, and would probably lean toward the higher end options. However, I don't listen at particularly high volumes and I don't need huge speakers, so maybe something like the Modula MTM would be for me. But how could I not upgrade to the TMWW???? :B

Improvement is, again, somewhat relative. Huge speakers can actually help things if you listen at low volumes - higher sensitivity, and more air moved with more ease to fill out the sound and give it body and realism. But if you want to test the waters, my MTM, the Natalie P, the Modula MT, would all be excellent options I think. The Jon's 2 are a bit more optimized - my MTM is designed to be an entry point into the world of low distortion drivers, and is fairly well suited to being placed any which way for the folks that want a one design option for mains, center, whatever. Price is about the same for my MTM or the Modula MT, sensitivity is not (MTM is more sensitive).

In a world where many different design philosophies exist, it can be hard to figure out which you prefer.

Oh yeah... you're just gonna go with the TMWW? small time.

C

[Dennis H]

Another issue is powerful low cost software for simulation. It doesn't exist, like there is for passive crossover design.

Au contraire. LspCAD 6 is equally comfortable with active or passive components.

[ThomasW]

At a little over $200US, most people don't consider LspCAD "low cost". That's too bad because it's a great program..... :T

[cjd]

ThomasW got it right... at least, for me.

C

[BobEllis]

I just have this thing about spending money on software for my hobby things. I look at that $200 and think "That's almost a couple of RSS12s."

Speaker workshop is pretty good for passive designs once you get by the initial learning curve, but I've been mucking about with freeware long enough. I guess it is time to come to grips with the fact that I could spend $200 on my router, why not a design tool?

[cjd]

Heh. If LSPCad did anything beyond speakers, I'd be more inclined.

My router gets used for furniture and other pfojects around the house - a far more versatile investment.

C

[---k---]

Chris,
It was the DynAudio 42s that you heard.

[cjd]

Chris,
It was the DynAudio 42s that you heard.

That's right. Nifty little speakers.

[rumatt]

Thanks for the replies!

I spent the last 2 days reading through the entire threads for the Modula MTM, Natalie P, Dayton TMWW's. Man they're long :E

The sealed Dayton TMWW is quite popular, but bass response is such that you may end up using a sub for music anyway if you have a big room (which I do). It seems questionable whether it's worth building a bigger, more expensive speaker, just to cross it with a sub anyway? I guess the advantages are that a) you can cross over to the sub a bit lower (but I don't see this as a big advantage if you have a good sub) and the 3-way allows a higher T/M crossover to put less stress on the tweeter?

What other advantages would one expect from the Daton 3-way over the NatP/Modula MTM besides bass response? I'd be interested in hearing more comparisons between these speakers. In these posts, Jim and Brian gave their thoughts after listening to all of the above, but they really only compared their TMWW's to each other.

But if you want to test the waters, my MTM, the Natalie P, the Modula MT, would all be excellent options I think.

My problem is that I have a serious case of upgrade-itis. If I build something, I want to take my time and be sure that I won't want to upgrade immediately afterward. I'm more concerned with ending up with a keeper than I am with minimizing cost.

The NatP's seem like a very reasonable first project, and I would probably love them. But I have to say I am drawn to the TMWW's, particuarly if I can run them full range so that I could relegate my (mediocre) sub to LFE duty for movies. If I'm going to end up using the sub anyway, then it's a much tougher call. Either way, I'll probably end up building the WTMW center at some point also, but I guess this would pair well with any of the mains.

[Amphiprion]

I own LspCAD 6, but have no experience with it so far (just too busy lately). I have used versions 4 and 5 extensively though, and judging by the new feature set of version 6 it is a very good value. It and Soundeasy are the two value contenders IMO. Once upon a time I had a very difficult time envisioning myself splurging on measurement and design equipment; now that I see what it can do, a $50 mic cable or a $140 microphone don't even make me flinch. Heck I have about $350 in just microphones, stands, mic preamp, and cables.

Don't think of them as tools like routers or saws. Think of them as very, very cool toys. It will open up speaker building to a whole new level for you.

[Dennis H]

What other advantages would one expect from the Daton 3-way over the NatP/Modula MTM besides bass response?

Just speaking generally rather than about these specific designs, a good 3-way will usually have a cleaner midrange than a good 2-way because you aren't making the mid driver do bass too.

I'll probably end up building the WTMW center at some point also

Well then, it's kind of a no-brainer. You should build L&R speakers that are as much like the center as possible if you want a seamless front soundstage.

[joecarrow]

You know, my Modula MTs sound fine at reasonable levels all the way down into the 40s, maybe even touching the high 30s. They might not hang together very will with loud rap and no sub, but I'm sure that even the MTs would mate well with a sub at reasonable volumes. One of the MTMs would do so at an even louder volume, or lower crossover.

I think the place where you'll see the most obvious example of your DIY project winning hands down over anything commercial is if you build a subwoofer.

[Dennis H]

Ditto what Joe said. Everybody needs a good sub.

[Inu_Yasha]

Ditto what Joe said. Everybody needs a good sub.

I echo what they say as well, especially if you're into movies! For my whole surround 5.1 system and the reciever I spent $720. For my sub and amp alone, I spent $620 and then $100 for a BFD and an Artcleanbox (which has yet to arrive). All in all, I spent the same amount for my sub as I did for the rest of my system, but I must say that it has made quite a difference in the realism of movies.

As far as speakers go, I would have to say get something that you'd be satisfied with the first time around or you'll end up like me, wanting to upgrade in a very short amount of time. I heard my neighbor's full range system and it sounds incredible; now I want to build me a set of full range (in particular the Dayton 3 ways).

[rumatt]

Well, the subwoofer issue is a saga in itself. Building my first DIY sub is what got me into this mess in the first place.

1) I ended up with this Dayton DVC 12" driver (OK I guess, but nothing special). I have two enclosures, one 1.2 ft^3 sealed, and one 4.5 ft^3 ported and tuned to about 21 Hz. I also have a BFD feedback destroyer to flatten the sub response.

2) I'm in a townhouse, so I can't really crank up the sub during movies. I'm currently not even using the ported enclosure. It was too much bass.

3) Despite having a relatively large room (23' x 30', plus another hallway and large kitchen), the front half of the room has no space for a large sub. I tried the sub in the back of the room and I couln't make it work. Bass is non-directional, but there are other signals that made it very distracting (floor vibrations, etc) For movies, the sub in the back of the room might be OK.

Bottom line: if the Dayton 3-way's are OK with no sub for music, it would be perfect.

[Inu_Yasha]

Well, the subwoofer issue is a saga in itself. Building my first DIY sub is what got me into this mess in the first place.

1) I ended up with this Dayton DVC 12" driver (OK I guess, but nothing special). I have two enclosures, one 1.2 ft^3 sealed, and one 4.5 ft^3 ported and tuned to about 21 Hz. I also have a BFD feedback destroyer to flatten the sub response.

2) I'm in a townhouse, so I can't really crank up the sub during movies. I'm currently not even using the ported enclosure. It was too much bass.

3) Despite having a relatively large room (23' x 30', plus another hallway and large kitchen), the front half of the room has no space for a large sub. I tried the sub in the back of the room and I couln't make it work. Bass is non-directional, but there are other signals that made it very distracting (floor vibrations, etc) For movies, the sub in the back of the room might be OK.

Bottom line: if the Dayton 3-way's are OK with no sub for music, it would be perfect.

See, I'm in the same situation as you in that I can't turn my bass up all the way... on the weekdays... Now when it comes weekend and nobody is really studying or home :twisted: In short, my little 14X22 (rough estimate) living room completely shakes when there's a high bass scene. I've already had my underneath neighbor complain about the shaking caused by my sub so I have to keep it down during the week.

As far as OP is concerned, I would have to agree with you rumatt. The dayton 3 ways would be excellent for music! OP, if you can go listen to someone who has a 3 way system, DO IT!!! You'll get a firsthand experience as to how one of these systems sound. I listened to one of my neighbor's system and it completely floored me, that's why I'm having severe upgradetits.

[cjd]

If you're vaguely feeling like you may be doing a bit of overkill, check out kingpin's thread. His adaptation of the 3-way WWMTM's Brian B and I put together (note, I also did a crossover for the center in the WTMW that should match up really well with these) will make a simple TMWW seem to be small-time. In some (small) ways the WWMTM's will do this. :P

C

[jonathanb3478]

I've already had my underneath neighbor complain about the shaking caused by my sub so I have to keep it down during the week.

I only have an upstairs neighbor. The neighbors across the way are not in the same structure and are a good 10' away.

The only thing I have received that might have been a compliant, was when the community news letter mentioned that "people" should check the level of their "subs" after quiet-time takes effect (10PM). This was a few months ago.

I don't watch action movies at 2AM (I used high dynamic-compression) anymore. Well, Ok, not as often at least. :twisted:

In my defense, I am a work-from-home, graveyard shift, IT admin.

[ThomasW]

Apartment/condo dwellers benefit from more from the use of tactile transducers more than any other demographic...

[rumatt]

If you're vaguely feeling like you may be doing a bit of overkill, check out kingpin's thread.

If I made speakers that big, I don't think my wife would let me bring them in the house.

[cjd]

If I made speakers that big, I don't think my wife would let me bring them in the house.

The trick is to do it one step at a time.

At first, they seemed big. Now, not so much. Time to move up!

Image not available

C

[Brian Bunge]

Chris,

I agree! I keep telling Ashley how my speakers are starting to look rather small. She thinks I'm on crack!