cone and dome materials

ITS BEEN MY EXPERIANCE THAT DRIVERS THAT USE THE SAME CONE AND DOME MATERIALS SOUND TERRIBLY ALIKE.I'VE READ OPINIONS THAT THINK ALL DRIVERS SHOULD MATCH IN CONE MATERIAL THROUGHOUT THE FREQ. RANGE.IN MY OPINION ,THE SAME CONE MATERIAL GIVES UNREALISTIC PRESENCE IN SOME FREQ. RANGES.
I THINK THAT IN THE 7000HZ-20,000 RANGE AN ALUMINUM INVERTADED DOME SHOULD BE USED.IN THE 3000HZ-20,000 RANGE A SOFT DOME NAILS THE VOCALS DOWN.TREATED PAPER OR MINERAL FILLED PAPER CONE MIDRANGE DRIVERS IN A SEALED ENCLOSURE WORK PERFECTLY IN THE 350HZ-3000HZ RANGE.ANYWHERE FROM 51/2 TO 61/2".MID BASS FROM 45HZ TO 350HZ IS ONE RANGE THAT I HAVE TROUBLE PICKING .I'LL HAVE TO SAY THAT THE ONLY TO SPEAKER MANUFACTURES THAT GET IT RIGHT IN THIS RANGE IS KEF'S EARLY MODELS AND SOME OF JBL'S MID 90'S MODELS.IF ANY ONE KNOWS THE MID BASS MATERIALS THAT THESE COMPANYS USED PLEASE POST.SUB BASS CAN ONLY BE PRODUCED UNCOLOURED AND NATURAL SOUNDING USING A PAPER/KEVLAR CONE DRIVER 12".PLEASE POST YOUR OPINIONS ON THIS MATTER.THANKS
 
ttvonau said:
Would you not agree that all metal dome tweeters xover below 5000hz have an unatural metalic presence in vocals.

I have heard one XOed at 1200 Hz that was very good -- not commercially available, and kind of exotic. And the Aluminum Jordan JX53 can be quite sublime (granted it isn't a dome).

In a lot of cases metal domes are hard but it is not an absolute. Domes in general have their own set of problems need dealing with.

Secondly,have you ever heard a poly woofer of any size or brand produce even close to the same tone a bass drum does?

I have to admit to not listening to very many poly woofers. Had some Harbeth 8s in the late 70s i rather enjoyed (in an MTM triangulated TL).

dave
 
I'm trying to figure out if any one else feels the same way about the material choices manufacturers are using.These days it seems in my opinion there improving the sound stage and frequence responses of there systems but sacrificing the actual tone,the realism,the piano sounds like a keyboard so to speak.Now I'm talking about the $300-$2000 range.Has anyone else noticed this trend ?Further,can anyone explain why the market maybe going this route?
 

CHRIS8

Disabled Account
2001-12-12 8:47 am
VA, USA
Ttnovau, I personally have never heard a metal dome that did not sound fatiguing after a short period of listening. Like you, I generally prefer soft domes..IF I must use a dome. I tend to stick to ribbon/planar tweeters, as they seemingly are near-perfect to me. The only real probelm left is finding a midwoofer to integrate well with it at fc.

As far as midwoofers, I prefer synthetic composites such as carbon fyber, aerogel, fiberglass and areogel. With the stiff cones, accurate tones and better high freqency power response are generally possible also. But it seems that it is little difficult finding good examples of these woofers, as many have serious breakup problems right above the passband. My favorite so far is the polykevlar from Focal. It has very little breakup compared to the others. The Scan Speak Kevlar sounds OK also, but has a limited upper response compared to many of the other examples of this material. Eton also makes some very nice sounding kevlars. You used to have to filter the peaks from these drivers, or use a very steep slope. But in the last couple of years their have been quite a few drivers released that have smooth enogh response to avoid such steep networks. I don't generally like poly cones, they seem to kill any sense of realism(life) IMO. I prefer paper over poly cones, but I just don't find any paper cones to provided the same detail of the synthetics.

As for subwoofers, their are only two real issues IMO: Cone stiffness and motor linearity. I do agree though, that a poly cone sounding correct in sub bass is rare. I know of a couple that sound natrual, but have unusually thick cones. As for paper, kevlar and metal cones...the same properties aer at issue. If it was stiff enough in the first place to eliminate the linear and IM distortions caused by a flexing cone, then only the motor is left to make or break the speaker.

As far as modern speaker design preferences...I do believe that many manufacturers are getting too caught up in measurements, and using them as marketing tools. So unesecarry corrective circuits(IMO) are being used to flatten 1 db peaks here and their, and overall, compromising a bit of realistic life is acceptable(as they see it) if a +/- 1 db response can be achieved. As IF this is really that important. How about some measurements of these speakers in an average listening room? Their 1 meter gated and/or anechoic lab measurements aren't so represenative of a the end user environment, now are they? The measurements should be used as 'tuning guides' during the design process, but I don't think that getting the measuements to look as pretty as possible for their brochure should be the ultimate goal. Also, aside from these issues...most professional designers have no freedom. They are forced to use certain drivers, cabinet designs, etc. Most pro desiigners aren't really 'creating' much it seems, but more so 'fitting' the pre selected parts to work as well as possible in the restrictions they have been given. Just one of the reasons many DIY designs smash commercial designs that cost 7x more.

-Chris
 
Thanks chris8 I'm glad to hear that I'm not alone on the subject.My knowledge of speaker building isn't very good.I'm learning what I can,and as I learn more about theories of design I've started questioning manufactures designs.I started thinking I was misunderstanding importand facts and theories and thats why my designs differed so much from manufactures.Now I'm thinking I should back and maybe explore some old ideas I've had.