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View Full Version : tweeter issues again...no idea what driver to go with



thadman
12-12-2006, 05:57 PM
After looking at Zaphs results on ribbon tweeters, it became quite evident to me that even if they could be crossed low with low distortion they all have serious energy storage issues down low...and I'd like to stay away from that if at all possible.

For the midrange, im still pretty content with the W18E. It looks to be the best option for my situation, but after reviewing zaphs new group it seems as if an even lower crossover solution would be welcome (1-1.2khz @ 48dB). Im getting it in a trade, so cost should be $160 for the pair. The Usher 8945P looks nice, but its energy storage is considerably worse than the W18E although its distortion performance is pretty phenomenal. Its a little too expensive for me to test at its current price point ($110/driver). I looked at the Audax PR170M0 spreadsheet on madisound and couldnt make much out from the information there about its distortion performance. It manages only a 95dB sensitivity between 300hz and 2000hz with a slightly rising response and finally peaking at ~3200hz with a 5dB breakup. Its decay performance was absolutely abyssmal compared to the W18E.

The new crossover point brings my *dome tweeter* options down considerably. I am stuck between the Peerless HDS 1", the Seas 27TDFC or the Seas 27TBFCG with a super low crossover point (1.4khz for the tweeter and 1.2khz for the midrange). The peerless seems to be the best option with the absolute lowest distortion. Although its decay performance is significantly worse than the Seas, it is still several orders of magnitude better than the cone it will be mating with so I believe the transience is negligeble. Am I wrong? I also have the ability to use several different settings since im using the DCX, so the low crossover point will only be used during daily listening levels (I cant see it being any more than 90-93dB)

Another option would be to use several BG Neo3s in a line array (I measured and the distance between diaphragms would be 1.5", ~8931hz), but I fear I may get lobing issues up high and the line source tweeter array may not blend well with the point source midrange (3dB vs 6dB loss for doubling of distance)

The BG Neo8 + BG Neo3 is also a possibility, but it comes at a much greater cost. Would a single BG Neo8 be sufficient for the top octave? It would allow me to cross at 1khz with ease and still manage fast decay times and low distortion.

Im not sure if this is possible, but I was thinking about bandpassing the BG Neo8 using the DCX2496 and using a simple 6dB filter on the BG Neo3 at 10khz. If I went active on the BG Neo8 and passive on the BG Neo3 could I somehow run them from the same amp?

All opinions and recommendations are welcome! Im greatly appreciative of all the help I get from these forums!

thylantyr
12-12-2006, 08:16 PM
Kudos for researching the subject that only confuses you more. You are
following the footsteps that everyone else takes, reading data and forming
conclusions. Your next step would be to buy all the drivers of interest and do
auditions, then you will see a huge change of opinion as soon as you turn on
your ears.

1. When you say ribbon, do you mean ribbon or planar? Two different animals.

2. Pure ribbons have a great sound reputation.

3. Cheap planars in a solo application are not great performers, but in a big line
array, they rule over the best solo dome. Pro planars will score more wins over
everything else including horns. Very expensive, $700 per tweeter.

4. Charts don't tell the whole story. Some of the best sounding midranges
that I like don't have the best charts. The best midrange I have that measure
best, overal scores last if you poll the audience.

5. BG Neo8 is a crap driver, solo or in a line array. BG Neo3 would be better in
a line array. PT2 planar in a big line array would be hard to beat provided that
you did low impedance wiring in spite that it's not very good solo.

Your best bet is to establish which type of system design do you want?

Do you want domes, ribbons or planars?
Do you want a line array or not?
Do you want high sensitivity or not?
Do you want a pure midrange or midwoofer?
Do you want wide or narrow dispersion from the tweeter?
A super low crossover point between the mid and tweeter is not good.
If you plan to use weak power amplifiers, only choose the high sensitivity
pure midrange drivers, ie PR17, and the higher sensitivity ribbons, etc.

etc.

If you plan to use a DCX, all active system, it's much easier to make
the random selection of drivers work. If you were doing a passive crossover
system, driver decision is more critical. The DCX is a powerful tool, give me
all the crappy drivers and I can make great sound as long as I have the DCX.

thadman
12-12-2006, 08:46 PM
This is the same system that Ive been asking questions about over the past few weeks. I've already got the DCX2496, a crown XLS-402B, and a pair of Dayton 15" HFs.

When I talk about ribbons...im talking about ribbons not planars. Im aware of the differences between them, hell I contemplated building a ribbon once and had the resources necessary but decided against it because the end result didnt seem worth it. All the ribbon tests ive seen had abyssmal low-end decay performance, pretty much everything under 4k decayed slower than the domes on several orders of magnitude.

How would a DIY planar sound? Id be interested in making a pair of 60" planars if they arent incredibly difficult to construct.

I modeled the displacement requirements for one on a 24" baffle, @ 110dB, @ 200/283hz.

http://www.linkwitzlab.com/spl_max1.xls

It requires 10.1cm^3 @ 283hz and 29cm^3 @ 200hz, that comes out to be about 2mm of excursion (im not sure if the linkwitz spreadsheet is peak to peak or if its one-way) if I used a 60" tall/1" wide line.

The only issue with planars, from what ive gathered, is their extremely low impendance. I'd have to build/buy a big transformer for it, which might degrade the sound. I'd love to direct drive it, but I doubt any amplifiers that dont cost $$$$ would be able to power it.

thylantyr
12-12-2006, 10:46 PM
This is the same system that Ive been asking questions about over the past few weeks. I've already got the DCX2496, a crown XLS-402B, and a pair of Dayton 15" HFs.

I'm fond of higher sensitivity designs especially higher sensitivity tweeters
and midranges for more dynamic impact in sound. If I were going to build
a 3 way loudspeaker using this criteria, I would look at the $100 - $300
ribbon tweeters. I'd probably pick the Fountek NeoPro5i because it's the best
bang for buck in the $300 price range.

If you can tolerate some sensitivity loss to gain wider dispersion, the LCY ribbons
have great reviews and some prefer them over domes.
http://www.e-speakers.com/products/lcy-components.html

I personally don't care as I would make the speaker either aligned at the
listening position as there is no big audience to satisfy or make a tilt/rotate
mech.

For a 3 way, there is no need for a midwoofer as the 15" woofers will do the
midbass job. It's optimal to get a pure midrange like the PR17 or PHL offerings. Integration to the tweeter would be cake.

All the ribbon tests ive seen had abyssmal low-end decay performance, pretty much everything under 4k decayed slower than the domes on several orders of magnitude.

Ribbon technology has great reviews, don't discount them based on that.
I have seen many reviews where people favored ribbons over domes and visa
versa, point is, the test data doesn't tell you about it's SQ potential. You can't rule out this technology.

How would a DIY planar sound? Id be interested in making a pair of 60" planars if they arent incredibly difficult to construct.

The good DIY planars would be the most difficult to DIY, you have a much better
chance at building a pure ribbon. The planar design I speak of is far superior to the junk you see in catalogs like PT2, HiVi, BG, etc., offers. Nobody has yet made
a pro planar tweeter DIY style, it's too complex, in fact there is only a few people
in the world who has executed a proper pro planar design that is so worthy, they
use them in pro sound applications, that's how good they are. You don't
see dome tweeters or ordinary ribbons on pro audio, hehehe.....

The only issue with planars, from what ive gathered, is their extremely low impendance. I'd have to build/buy a big transformer for it, which might degrade the sound. I'd love to direct drive it, but I doubt any amplifiers that dont cost $$$$ would be able to power it.

The planars that I'm referring too are in the 4 ohms to 13 ohms and use
no transformers. I don't know what other planar you are referring too.

thylantyr
12-12-2006, 11:07 PM
Pics from cyberspace;

Fountek NeoPro5i
http://home.pacbell.net/lordpk/temp/NeoPro5i-1.JPG
http://home.pacbell.net/lordpk/temp/NeoPro5i-2.JPG
http://home.pacbell.net/lordpk/temp/NeoPro5i-3.JPG

Morel, PHL1340, Peerless XLS system.
http://home.pacbell.net/lordpk/temp/6.JPG

Those 1340's have phase plugs, cool. This is 'Branwells' system. He compared
the PHL design to another design where he used Seas Excel. Overal, he also
prefered the PHL version as having a cleaner top end, but the Seas might
have edged it out on bass.

Fountek ribbon, PR17 midrange, and Lambda TD15X woofers, dipole design.
http://home.pacbell.net/lordpk/temp/1.JPG

If it was me, I'd port the TD15X and center align the drivers.



Substrate's speaker, his dad in the pic.
http://home.pacbell.net/lordpk/temp/3.JPG

Raven tweeter, PHL mids, Lambda 12" woofers.




Feandil's 3 way loudspeaker.
http://home.pacbell.net/lordpk/temp/2.JPG

Home made ribbon, later replaced with a AC, dual PHL1120, dual
Lambda TD15X.



I have pics of the AR5 3 way loudspeaker using AC ribbon, PHL 10" midrange,
and Lambda 12" woofer.



If you want to explore line arrays, I have alot of cyber pics. Here is two
for now.

John J. {AE speakers} line array using a tweeter similar to PT2 and
$20 midranges. This is the biggest 'PT2' tower I've seen in cyber, 12
PT2 per channel. My PT2 array is only 10 PT2 per channel.
http://home.pacbell.net/lordpk/temp/5.JPG



My budget line array.
http://home.pacbell.net/lordpk/robarray/

thadman
12-12-2006, 11:50 PM
I have a book on DIY ESLs and the author mentions that ESLs are black and white. If your concept is good and you do it right, they sound phenomenal or they just dont work.

I dont understand how a *pro* esl would be any different from a conventional ESL. Is the diaphragm absolutely massive? (super tall...for Pro applications I cant see a wide ESL being useful as the beaming issue would be absolutely horrendous). The stator to stator spacing would either be incredibly close (super high efficiency), far apart (high output, but bad efficiency), or using an incredibly lightweight diaphragm. Output is dictated by displacement and as long as I possess enough power and highpass them, they should get just as loud as a super efficient design.

I never said ribbons were bad drivers. I mentioned that they have horrid energy storage problems on the low-end, compared to their phenomenal high frequency performance.

I doubt im going to be listening to my system at *realistic* (110dB+) levels, so insane efficiency and output isnt as important as high fidelity.

thylantyr
12-13-2006, 01:00 AM
Ribbon, planar, ESL are all different technologies.

Ribbons - There are some good choices on the market from under $100
to a few thousand bucks. Usually the more expensive ones have lower frequency
response. I think the lower frequency response is over-rated as there is no
guarantee that you will prefer a very low tweeter crossover *unless* you
auditioned one, therefore I would limit the choice to no higher than $300 each.

Planars - The ones you see are Dayton, Hi-Vi, BG and some other clones, nothing
special really unless you line array the smaller ones and wire them for lower
impedance if you want to boost performance. In a line array, the $25 planars
can dish out some crazy punishment if you make a large stack.

Pro-Planar - I can think of only three proaudio companies that use them, of
those three only one will sell the raw driver to DIY'ers for about $700 each.
This is my all time favorite tweeter that I've been slowly collecting for years
to a future build. A line source of these is SPL punishment and death at
audiophile sound quality.

ESL {panels} - Some people build their own, the store bought brands are pretty
nice, but they have SPL limitations, not cheap. You might want to look into
this DIY style since you don't want higher SPL levels and you want nice SQ.


************************************************** *************

The only way to find peace of mind on tweeter selection is to buy one of each
tweeter technologies to sample. Buy one quality dome, buy one Fountek $118
ribbon, buy one LCY ribbon as they are very good and may surprise you, and
don't bother buying the non-pro planars as they aren't really worth it in a solo
application. If you want to do a line array, then your choices are ribbon, planar and maybe one or two dome tweeter candidates.

Right now you should be doing some listening tests on those Dayton 15's
using the Crown amp to see what is the tolerable upper crossover point,
this will help you choose a midrange. What if that woofer doesn't sound good
at the higher low pass? You need to verify this now, make a cheap test box
or just play the woofer free air on the test bench.

Scoobydoo
12-13-2006, 04:02 AM
John J. {AE speakers} line array using a tweeter similar to PT2 and
$20 midranges. This is the biggest 'PT2' tower I've seen in cyber, 12
PT2 per channel. My PT2 array is only 10 PT2 per channel.
http://home.pacbell.net/lordpk/temp/5.JPG



his shop is about 5 minutes away from me

last i talked to him he was coming out with a new line of drivers, but i am not sure if that will ever happen:(

thylantyr
12-13-2006, 12:54 PM
his shop is about 5 minutes away from me

last i talked to him he was coming out with a new line of drivers, but i am not sure if that will ever happen:(

So he *is* alive? :crazy:

He seemed to have vanished from cyber and his forum closed.

He's the last hope if anyone wants a Lambda caliber woofer :)