AVS Forum banner

Status
Not open for further replies.
1 - 16 of 16 Posts

·
Registered
Joined
·
182 Posts
Discussion Starter #1
I've been auditioning speakers lately and I've notice something I never expected. I was curious what others thought.


My current speakers are DefTech BP2000's with a C/L/R 2000 center channel. I've had them for three years and until I got rid of the big RPTV and replaced it with a plasma was quite happy. I liked the BP2000's with the RPTV between them as it seemed like the bipolar speakers helped the soundstage. Now, with much less bulk between the speakers I find precision lacking. The soundstage is wide, but too vague for my taste. So, I've begun auditioning speakers.


Most have had metal dome tweeters (including my DefTechs) and I've found them a bit too "forward" though I never knew this until I heard something else. The best analogy I can find is not knowing I was in pain until the pain went away.


I heard a Meadowlark Shearwater HR which is a 2-way design with silk dome tweeters and I was amazed. Everything seemed much more articulate and the speakers "vanished" for me more than anything else I've heard yet.


The other speakers I heard were Aerial Acoustics 7B's and 5's, an Energy monitor whose model number escapes me (might have been an Encore), B&W Nautilus 804 and 805's and Thiel 2.3's. All of those were metal dome tweeters, mostly Aluminum, I think.


Is there that much of a difference between metal and other tweeters? Or is it that most speakers are designed by men and most men start to lose the highs in their hearing before women and the silk/metal was a coincidence?


It's really got me curious and I'm trying to find other speakers that look promising to figure out what I like and dislike in the sound.


I'm not trying to claim that one is more "real" than another - only what seems to sound best to my own admittedly uncalibrated ear.


Any thoughts?
 

·
Registered
Joined
·
533 Posts
Something to consider carefully is that you compare speakers with the same electronics. Amplifiers don't sound alike, and unfortunately a lot of mid priced to moderately upper end solid state electronics do have colorations that will drive me crazy on an otherwise very transparent system.


Metal dome tweeters have often gotten a bad rap. Now, there are differences between different metal dome tweeters, and personally I prefer the Focal titanium tweeters which have a tioxid surface coating which contributes both to stiffness and damping of the dome. I also like the Accuton ceramic dome tweeters and midrange drivers.


Cloth dome tweeters seem to be more "forgiving", and less "analytical", but with my experience designing both speakers and amplifiers, and trying to understand the interaction between them, I've come to the conclusion that the ultimate in fidelity is achieved by the combination of a very fast, detailed tweeter with a damped ultrasonic resonance at the highest possible frequency, combined with either low feedback vacuum tube electronics (*not* SET's though! too colored and otherwise compromised!) or zero feedback solid state equipment (Ayre, Theta Digital, BAT).


Some would argue it's the system synergy that counts, and while it's true that a cloth dome tweeter will make a conventional solid state amp more "musical" (less fatiguing), it also obscures musical detail. And the forwardness I hear with even well regarded conventional solid state amps like Aragon in the upper end is not just frequency balance; it's distortion, typically IM.


To summarize, with speakers, no driver should be used outside it's pistonic range. Few companies follow that adage; check out Avalon and Audio Physic models, as well as some Joseph Audio models, if you want to see what that sounds like.


But they must be mated with first rate electronics. In general, the colorations of less expensive tube amps, like Anthem and the lower cost Conrad Johnson models, are much less musically annoying. But if you have a chance, give an amp like an Ayre V5 an audition; I think you'll very much like what you hear. It's reasonably powerful (150 watts/ch @8 ohms, 300 watts/ch @ 4ohms), wide band (to 200 kHz; no premature roll off), and has the cleanest, most dynamic transient reproduction I've heard in solid state to date. A good match with the Ayre V5 is the Avlon Eclipse Classic, or the Eidolon or Opus. These combos may really surprise you with what they will do with music. Give them a listening, if only to recalibrate your expectations.


Good luck with your search, and happy listening.


Regards from an aging male,


Jon
 

·
Registered
Joined
·
430 Posts
Linda,


A "forward" sound is, believe it or not, often unrelated to the tweeter. The extra harshness is attributable to the upper regions of the low frequency driver that usually handles frequencies up to some 2.5-3 kHz, covering the entire 1-2 kHz "harshness" region.


A properly designed metal dome should have its first bending mode ("break-up" - the diaphragm is no longer moving like a rigid piston) well out of the audible range (> 20 kHz). This is because the loss factor of the metal is quite low, making a dome in resonance ring like a bell (although much higher in frequency of course). Simply put, modern metal domes are generally quite well-behaved.


But aside from anything directly related to the speakers, it is just as likely that you may have heard a speaker that was perfectly matched to the rest of the system, room and program material.


BTW, my HF hearing is way better than my wife's :).
 

·
Registered
Joined
·
1,031 Posts
Hello -


There are a couple of other fine points of which to be aware regarding metal dome tweeters:


1) You must be sure and separate metal dome tweeters into two categories. By far the most common variety has some sort of plate in front of the tweeter dome. This plate is sometimes called a "diffusor" or "phase corrector" or some other such nonsense. It actually is an acoustic resonator that rings like a bell at 15 kHz or so. This resonator is actually what makes metal dome tweeters sound "metallic", and not the dome material itself.


The other category of metal dome tweeter lacks this plate. These tweeters sound very natural and transparent, with (believe it or not) a "silky" sound. In contrast, soft dome tweeters will always exhibit some colorations, generally of a "fizzy" character.


2) A metal dome tweeter (especially without the plate in front of the dome) is an extremely transparent device. It will make shortcomings in the parts quality of the crossover or of the driving electronics all too obvious. The colorations of a soft dome tweeter will hide these sins behind its own.


Hope this helps,


Charles Hansen
 

·
Banned
Joined
·
806 Posts
Linda, could you describe your setup to me? Specifically, how much space is in between the speakers, how much space for the rear drivers to fire, how much space for the built in subs to fire, degree of toe in, subs firing in or out, amplification used, other associated equipment, and finally room dimensions/characteristics.


I have the 2000TL's...I have found them to be wonderfully musical. In fact, I think I actually prefer listening to music on them now (although these speakers are totally killer with movies). I have mated my DT's with a yamaha dspA1...even though yamaha has never been known to tone down the high frequencies, I have not found these speakers to be bright at all...very crisp and clear in the higher frequencies. I think the key is to make sure that the front and rear-firing tweeters are not placed too close to any wall or object. Matching associated components with these DT's is VERY important...initially I had a denon 5600 hooked up, and the sound was very flat. The DT's will reveal any differences in cables, cd player, etc. I am assuming that you are using some decent cables...make sure that they are not coiled or cluttered...if you have excess cable, wrap it in a non-overlapping "s" pattern. Also you might want to give each speaker it's own power outlet. Wrap the excess power cord for each built in sub in a non-overlapping "s" pattern as well. You might also want to try a power conditioner. I have wired my speakers "full range" in the bass...to get very nice, tight, tuneful bass, you must wire these speakers in such a fashion. I have not felt the need to bi/triwire my speakers, but many many people have noticed significant improvements after doing so.


Take a look at these links for some different thoughts on how to set up these speakers to perform "optimally" with music.

http://forums.consumerreview.com/crf...ouJ^[email protected]

http://www.audioreview.com/reviews/S...uct_7146.shtml

http://www.audioreview.com/reviews/S...uct_8728.shtml


I know that you have the 2000's and not the newer 2000TL's...but what I have said should apply for the 2000's.


Notice how several have found the 2000/2000TL's to compare favorably with Nautilus 802's (8k/pair).


Of course, a large bipolar powered tower will not work well in every room...but if you give these DT's enough room to breathe, they should astound you.
 

·
Registered
Joined
·
182 Posts
Discussion Starter #6
Wow, great responses - thanks to all! I've learned more about speakers in the past month doing research than I ever thought I'd want to know. It seems I've still got some education left to assimilate.


bob23, regarding the DefTechs - I've gone through many room and speaker layouts trying to maximize the speaker's potential. When I had the bulk of the rear projection television between them I was very happy with the speakers, but now with the much trimmer plasma between them, I've fallen out of love :(


I have tried them closer and further from the walls. The best position I've found is about 5.5' from the back wall. This comes closest to solidifying the soundstage but it's still more diffuse than I'd like.


Regarding my setup, I have a Yamaha DSP-A1 integrated amp driving them though eventually that's going to be replaced. I plan to move to a 7.1 configuration at some point next year and will likely go for separates.


Now the half doze or so speakers I've heard in the stores were driven by quite different gear from Theta to something that was supposed to approximate my Yamaha. That's what led me to the possibility that the tweeter was the one thing in common among all of them. It may not be the actual issue, but it was the first thing that came to mind.


Again, thanks and if anyone has any additional suggestions, I'm all ears!
 

·
Banned
Joined
·
806 Posts
Linda could you describe your room dimensions/characteristics to me? How are the speakers placed right now? How much space in between and to the sides and rears, and how far is the primary listening position from the speakers?


Generally I recommend giving the speakers 1-3 feet of space for the rear drivers to fire. You do not want to give them too much space because then the sound will be too diffuse IMHO (for a setup used with music). Another important thing to note is that the spacing in between the speakers should be limited...I would recommend 5-10 feet of space in between the speakers. You should use a slight toe in towards the listening position. You probably want the built in subs to fire outward...and they should be given at least a few feet of breathing room on the sides.


Have you wired your speakers "full range" in the bass? Have you bi//triwired them?


One thing the 2000TL's seem to like is a nice large room...my room is 25x20x25 ft (LxWxH). My listening position is at least 10-12 feet away from the speakers, and I only have 4 feet of space in between the speakers (because they must be placed in a walled insert).


I think the key to getting the 2000TL's to sound excellent with music is to try to "control" the bipolar effects/reflections as much as possible. A large room will certainly help here. Also, minimizing the spacing in between the speakers will help...doing so will allow you to use less toe in, which will result in less rear-radiated energy directed around the room.


What cd player and cables are you using? I use some decent Monster cable, and an old Sony 5-disc cd player, with excellent results. However, I have found that the sound with CD's is much worse when using my JVC dvd player as a source.


I consider the yamaha dspA1 + def tech 2000TL to be a neutral combination. This will give you crisp highs, but they should not be bright if you have matched associated equipment well. If you prefer a softer high end, you should consider mating the DT's with a b&k avr307...I think you should be pleased with the resulting warmer sound.
 

·
Registered
Joined
·
430 Posts
Charles,


I believe the phase plug is placed in front of the tweeter to reduce the effects of break-up. This means that the metal dome is less than optimal in the first place and the phase-plug is only there to act as an acoustic band-aid. The resonance or ringing is thus not due to the plug itself.


Still, I second your opinions regarding the sound of phase-plug and non phase-plug tweeters.
 

·
Registered
Joined
·
182 Posts
Discussion Starter #9
Quote:
Linda could you describe your room dimensions/characteristics to me? How are the speakers placed right now? How much space in between and to the sides and rears, and how far is the primary listening position from the speakers?
I have a picture that would be better than my explanation, but no accessible place to put it so I can link to it, so you'll have to suffer through my description.


These dimension are really for three rooms which open one into the other. Overall, it's roughly 31x14' with 8' ceilings. The speakers are 5' away from the front wall and 3' away from the right wall and 5' from the left wall. The asymmetry is due to a short wall that seperates the sun room from the living room. The speakers are just inside the sun room. I know it sounds odd, but I've tried all the other variations and this one has worked the best so far. I can email a picture to anyone who's curiosity isn't satisfied by my descriptive abilities.


The speakers themselves are roughly 6' apart center to center. The primary listening position is 7' back. The speakers are toed in a fair amount as that seemed to focus the sound the best.


The listening position is far from the rear well, 15-16' I'd guess.


My only other options for room arrangements put the speakers and listening position only 1' from the front and rear walls and I didn't care for that at all.


If I push the speakers and display further back into the sunroom, then it doesn't work for furniture layout and aesthetics.


I'm hoping to listen to more speakers tomorrow and it will be interesting to see if my what comes out of that in terms of liking the sound. Earlier someone mentioned Joseph Audio and I'd love to hear them but haven't had any luck getting a response from the company about dealers. Anybody know of one in northern Virginia or Maryland (perferably near DC)?
 

·
Banned
Joined
·
806 Posts
I would recommend moving the speakers back a bit...give the rears a couple feet to fire. Also toe them out a bit. 5 feet of space for the rear drivers to fire + a lot of toe in = very reflective sound IMHO.


Are the subs firing outward or inward? What cdplayer and cables are you using? Have you wired "full range" in the bass, as well as bi/triwired?


Your listening position does seem a bit close...ideally you would want to be at least 10 feet away from the speakers.


What exactly are you main criticisms about the sound, and how has the sound changed after removing the rptv?
 

·
Registered
Joined
·
1,077 Posts
Linda,


Don't know if you had a chance to listen to Dynaudio speakers or not, but there power handling capability, silk dome tweeters, and excellant midrange produce a very neutral sound with pinpoint imaging and great soundstage depth.


I'm talking about speakers that are positioned to face forward (no toe-in) about 7' apart, about 7-8' to the listening position, in a >3000 cuft room with a couple large openings.


By the way, I use to live in a townhouse in Reston down by Lake Ann in the middle 70's. Great community.


BruceD
 

·
Registered
Joined
·
182 Posts
Discussion Starter #12
Bruce,


The closest Dynaudio dealer is over in Maryland. That will mean a weekend visit. I'll have to check them out.


Bob,


Sorry, I got so caught up in the room, I forgot to answer the other questions...
Quote:
I would recommend moving the speakers back a bit...give the rears a couple feet to fire. Also toe them out a bit. 5 feet of space for the rear drivers to fire + a lot of toe in = very reflective sound IMHO
Agreed, it is very reflective, but logistically it's a choice between 1' and 5'. I tried putting a couple of people standing behind the rear drivers to absorb the sound and liked that a lot better. Shame they wouldn't stand there for hours though. :)

Quote:
Are the subs firing outward or inward?
Inward. Tried both ways and didn't hear much difference.

Quote:
What cdplayer and cables are you using?
I've used a Sony 5 disk changer whose model escapes me and a Panasonic a310 dvd player. Both are connected through optical cables. Probably Monster optical cables since I think they're the only thing available locally or were at the time anyway.

Quote:
you wired "full range" in the bass, as well as bi/triwired?
They're biwired with DH Labs silver sonic cables. I've tried setting the speakers to small with the bass coming over from the LFE out and setting the mains to large with the subwoofer off and jumpering the bass cables. I've preferred the sound that way. Presumably because the bass crossover in the speaker was a better match for the driver than the one in the amp. The difference was small but noticeable.

Quote:
Your listening position does seem a bit close...ideally you would want to be at least 10 feet away from the speakers
Yes, it's basically an equilateral triangle, perhaps just a touch longer than equilateral. That distance is determined by the display. For my (less than stellar eyes), about 7.5' is the right viewing distance. If I get the speakers 10' back, I'll either be too far from the display or the speakers will be behind the plane of the display.

Quote:
What exactly are you main criticisms about the sound, and how has the sound changed after removing the rptv?
The soundstage became much more "fuzzy". Instruments went from being in a a more localizable place to being in a larger, more diffuse space. That's my primary complaint. I've tried everything from 6" to 6' from the front wall to see what would help. I've also tried from 5-10' between speakers as well as various toe-ins. Where they are now is the best I've been able to obtain.


The soft vs. metal tweeter thing was just an observation that I had made while listening to other speakers. I've only heard one soft tweeter so far and I really liked the speaker. It was the most invisible against the speakers I heard. But, I've got nothing against the sound of the DefTech. But I am believing that given my changed listening/viewing configuration that these are no longer optimal.


It's kind of funny, because I specifically wanted them because of the RPTV. I thought the bipolar nature would help fill-in the soundstage and I think it did. It wasn't until 3 or 4 months ago when the plasma came that I became unhappy and started giving my friends hernias helping me try room arrangements.


Whew, I have to learn to be less long-winded...
 

·
Banned
Joined
·
806 Posts
I have wired my 2000TL's in such a fashion:


I send the long end of a y-connector to the "full range low level in" on the speaker, and send the two shorter ends to the "main in" and "pre out" on the receiver. Then I send a "normal" speaker cable from the "mid" jumper on the speaker to the main (L/R) inputs on the receiver. Of course you do this for both speakers. The speakers should be set to "large" with "No sub".


I recommend having the subs firing outward because the bp2000's have an offcentered tweeter. When the subs fire outward, the tweeters are offcentered inward...in this configuration, less toe in is needed since the voices are more easily centered.


From what you have told me regarding placement restrictions, you would probably be better off using a different set of main speakers. A large bipolar powered tower really needs a decent amount of room to breathe. You should look into direct radiating speakers. I think you will enjoy the Dynaudio sound.


As for Def Techs tweeter...yes it is made of aluminum, but it is a special design. The pure aluminum dome is specially annealed (to "relax" the crystal structure) and acoustically loaded by a precisely configured acoustic phase plug/lens (to assure perfectly controlled, absolutely linear movement). In addition, the unique silk surround provides better dampening and wave termination. Basically, this is said to brings together the performance advantages of metal domes (greater clarity) and soft domes (smoother sound and better dampening) in one state-of-the-art tweeter design.
 

·
Registered
Joined
·
182 Posts
Discussion Starter #14
Bob, thanks for all your excellent comments and your desire to explore this!


Your conclusion is pretty much the same one I'd come to. Through no fault of the speaker, it's no longer suited to my room. It can probably be argued that it was marginal to begin with, but it seemed like a good idea at the time.


It may also be my own tastes changing over time as well. Perhaps I've come to appreciate a precise soundstage more than I did a few years ago. I sure hope it's not a case of familiarity breeding contempt, but I don't think it is. Under the right circumstances, I think the DefTechs are great speakers and I like the looks as well.


I'll try to give the Dynaudio's a listen as well as the Joseph Audio's if I can find a dealer for the latter.
 

·
Premium Member
Joined
·
5,900 Posts
When I was involved with the original Fosgate Audionics home theater system in the early '90s, we contracted John Dunlavy to design the speakers. I learned a great deal from him about tweeters. John liked Dynaudio and Morel tweeters with cloth domes at the time, because most metal dome tweeters, although quicker, would ring like a bell. Impulse response tests proved this. (John, my friend, also liked 1st order slopes, which is where we disagreed.)


Now, working with our own engineer David Nelson at Triad, I'm being told the same thing. In four of our speaker models, we use a HIDEOUSLY expensive cloth dome tweeter from Seas, and it performs better than any other dome tweeter we've auditioned. I don't believe the best way to reduce tweeter "ringing" is to cover it up with slower (tube) electronics, but, rather the problem should be dealt with at the source. (I like good tubes, though.) TYPICALLY, metal dome tweeters ring more than cloth dome tweeters, if I can make a general statement.


As far as woofers are concerned, there is little romance in the term "paper cone", but despite mylar, bextrene, polycarbonate, unobtainium, polypropylene, etc., paper-derived cones are still as good or better than anything. They can be made very stiff, very light, and without any significant resonant modes. We use expensive drivers from scan-speak that are sophisticated paper-cone units, and in a 5.25" driver would have a retail price of $300 each or more.


I would be suspicious of marketing types (oops..I AM one...) that claim that an exotic material, by itself, means a driver is superior.
 

·
Registered
Joined
·
1,031 Posts
Iceman wrote:


"I believe the phase plug is placed in front of the tweeter to reduce the effects of break-up. This means that the metal dome is less than optimal in the first place and the phase-plug is only there to act as an acoustic band-aid. The resonance or ringing is thus not due to the plug itself."


Actually, the "phase plug" (a very misleading term, created by marketing types) has a very different function. A typical 1" metal dome tweeter will normally exhibit a slight droop in the upper octave, say a few dB down at 20 kHz.


This droop is due to the curvature of the dome itself. From the listening position, there is a path-length difference between the center of the dome and edge of the dome. This difference produces acoustic cancellations at extremely high frequencies, and hence the slight droop in the upper octave.


The "phase plug" acts as a Helmholtz resonator (like a miniature bass-reflex cabinet) to boost the output in the range of the droop. This results in a flatter steady-state frequency response, but the transient response is severely degraded due to the ringing (resonance) of the trapped air. This ringing is what produces the "metallic" coloration.


But the resonance from the Helmholtz resonator has nothing to do with the dome material. It would happen also if a "phase plug" were placed in front of a soft tweeter dome. Then one would have a "metallic" sounding soft-dome tweeter.


A soft tweeter dome would also suffer from a response droop due to the curvature of the dome. However, the floppy diaphragm has its own resonances that (through a lot of trial and error) can boost the response in the upper octave to achieve a flat steady-state frequency response.


These diaphragm resonances are what causes a soft-dome tweeter to sound "fizzy". The acoustic resonance created by the "phase plug" of a metal-dome tweeter cause it to sound "metallic". However, a "naked" metal dome tweeter only exhibits resonances well beyond the audible range, and will actually sound "silky" and "sweet", just like live music.


Hope this helps,

Charles Hansen
 
1 - 16 of 16 Posts
Status
Not open for further replies.
Top