Not a bad idea to make up a pair of mdf test boxes before committing to multi-layer plywood/veneer boxes. E.g. my next project is a Russian Baltic Birch Ply MTM Rendition set.
(btw, Rendition link: http://www.diyaudio.com/forums/multi-way/274085-renditions-anarchy-tmm-mtm-build.html)
Although mdf has a bad reputation, it's not all the same, pic below is a sample of cabinet grade mdf.
In this area the box stores are loading their racks with a low grade mdf, it just looks like rubbery-junk; will never use that for a speaker project! There's also the really dark brown product, it just disintegrates when cutting and dust goes everywhere in a few seconds.
(btw, Rendition link: http://www.diyaudio.com/forums/multi-way/274085-renditions-anarchy-tmm-mtm-build.html)
Although mdf has a bad reputation, it's not all the same, pic below is a sample of cabinet grade mdf.
In this area the box stores are loading their racks with a low grade mdf, it just looks like rubbery-junk; will never use that for a speaker project! There's also the really dark brown product, it just disintegrates when cutting and dust goes everywhere in a few seconds.
Your mention of MTM reminded me, would someone be willing to describe the difference I might expect in general between the sound of a D'Appolito versus a 2 way system? I have read the descriptions of lobing and imagery, but I'm wondering if I'm interpreting it correctly. With twice the mid bass surface area I would expect a warmer, more full and blended sound but I worry about overwhelming midrange or a muddy, bassy sound.
Gaglers,
I wouldn't consider them warmer, but done correctly you may have less vertical bounce from ceiling and floor, giving you a clearer image at your listening position. One reason why my designs use tweeters with a long vertical surface. :0
Also note that D'Appolito has updated his thoughts and last I heard was recommending a 4th order crossover for improving off-tweeter angle effects.
Honestly, the things youv'e described about overwhelming midrange or bassy sound have more to do with how the individual speaker's are tuned. I can design any type of speaker with those qualities...
One issue that may occur, but I'm not sure about D'Appolito's is how the energy dissipates between the speaker and the listening area. That is, if one driver is radiating more widely it will loose more energy per foot of distance than a driver with planar, or narrow dispersion. This is what makes electrostatics "hard to match." The issue tends to be that the planar looses less energy at 10' than the woofer's have, so you have to adjust your listening distance, or adjust your woofer levels to match.
Personally I think there are a lot of other myths about matching an electrostatic with a woofer, but that's for another thread.
What I might suggest is why don't you experiment on yourself? You have a lot of questions, and honestly a lot are going to have to do with your tastes at the end of the day. Set aside some cash to do some prototyping with cheap parts. Get a cheap box and try out a D'Appolito, then try again with a woofer off.
Of course, you'll have to make more adjustments than this, but from what I've seen of all your questions, I think you should jump in and start listening for yourself soon. A couple of cheap prototypes will teach you much more about your likes and desire to build a kit than all the forums in the world.
Best,
Erik
Gaglers,
While I'm thinking about it, you should also post some information about your room size. Last thing, in my opinion, driver quality trumps all. Certainly it's fun to learn about and empirically research different design types. 2-way, ported, sealed, time-aligned, and D'Apollito but all pales to driver quality, room matching and crossover design.
To me, driver quality is about stored energy, or lack thereof first, followed by frequency range and lastly, dynamic range.
Room matching refers to having the right amount of bass, as well as matching the dispersion to where you will place it, as well as the acoustic treatments you plan to use.
Best,
Erik
While I'm thinking about it, you should also post some information about your room size. Last thing, in my opinion, driver quality trumps all. Certainly it's fun to learn about and empirically research different design types. 2-way, ported, sealed, time-aligned, and D'Apollito but all pales to driver quality, room matching and crossover design.
To me, driver quality is about stored energy, or lack thereof first, followed by frequency range and lastly, dynamic range.
Room matching refers to having the right amount of bass, as well as matching the dispersion to where you will place it, as well as the acoustic treatments you plan to use.
Best,
Erik
Erik, thanks for the perspective and great insights, I was beginning to draw the same conclusions myself. I already have a pair of 2 ways in office, the Vifa kit I made 15 years ago that I love. I will pull the trigger on the Blues MTM kit after the first of the year and report back with results.
Which is why he is thanking me separately. There's thanks for me, and the thanks for the experts. Makes sense!
Erik
Member
Joined 2009
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Don't worry Erik, you'll be an expert too one day
I was wondering, given that there is already a pair of big subs if they shouldn't be part of the consideration, I.e. Treating them as the bottom end of a 3 way, would that change any of the considerations ?
I would vote for a two way too Ver the MTM so that a higher quality woofer can be used for same price as two. The quality of the drivers would be the priority for me.
I was wondering, given that there is already a pair of big subs if they shouldn't be part of the consideration, I.e. Treating them as the bottom end of a 3 way, would that change any of the considerations ?
I would vote for a two way too Ver the MTM so that a higher quality woofer can be used for same price as two. The quality of the drivers would be the priority for me.
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Don't worry Erik, you'll be an expert too one day
I was wondering, given that there is already a pair of big subs if they shouldn't be part of the consideration, I.e. Treating them as the bottom end of a 3 way, would that change any of the considerations ?
I would vote for a two way too Ver the MTM so that a higher quality woofer can be used for same price as two. The quality of the drivers would be the priority for me.
I agree with you about part quality trumping speaker design.
As for the subwoofer, I usually tell those few with the courage to ask me that subwoofers are the third child of the devil. Hard to place, hard to integrate and usually users buy too much sub woofer for a room.
Also, for music, a good 2 way won't need it in medium to small rooms. Check out the in-room bass response of my current two-way speakers, using ScanSpeak 6.5" Revelators:
This is in a room with a pair of Glik Acoustics soffit traps standing in one corner and 3 of their acoustic panels distributed around the room.
The subwoofer is used exclusively for movies, where it does a great job. I still run the L and R speakers as full rangers, where they do a really nice job of filling in for the smaller (f3 = 120Hz) center channel speaker I'm using.
Best,
Erik
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