View Full Version : tweeter extremes...which end of the spectrum to choose?

12-06-2006, 07:27 PM
I've got the opportunity to snag a pair of Aurum Cantus G3s for a REAL nice price. I could get them for ~$350 shipped for the pair or so.

Now, heres the problem. The midrange im using is the Seas Excel W18E, and it REQUIRES a 1.6khz crossover minimum (huge 3rd harmonic peak at 1600hz). I've been planning on using the Peerless HDS 1" tweeter, because its capable of running that low but I would absolutely love to run a pair of ribbons:D

I picked up a brand new Crown XLS-402 on ebay for $220 shipped, and have yet to decide whether it has enough power to run a pair of Dayton Reference 15s in OB. If not, I can hook it up to my W18Es and get a XLS-602 (only 200 more watts) for the 15s, but $150+ more. Regardless, I have the budget to power the W18Es to their liking (theyre being crossed at 250hz) and will have >200 watts x 2 @ 8ohm available for them.

The Peerless HDS 1" would cost $120 shipped + $240 for a Crown XLS-202 ~$360

The Aurum Cantus G3s would cost about $330-350 + $30 for a t-amp

(100dB sensitivity...Im only going to need a few watts to level match with the seas and daytons)

Aurum Cantus recommends a minimum crossover of 2300hz for the G3 (not sure what order the filter is). I am required to cross the ribbon at 1.6khz at the highest, but have access to LR8 filters.

Which option should I go for?

Also, should 400 x 2 @ 4 be enough for a pair of Dayton Reference 15 HFs on a 24" Open baffle from 50-250hz?

12-06-2006, 08:47 PM
AC G3 is cool.

But the Fountek NeoCD 2.0 for $118 is hard to beat since it has similar specs
as G3. The money saved can be used to get a better amplifier to drive the


If you are doing the fully active setup with low powered amplifiers, then
you should look into the higher sensitivity midranges and Seas isn't one of
them. Audax PR170M0 is your best bet, great bang for buck. PHL1120 is
similar in sound, but more robust in design.


If you have more power to drive the midrange then the lower sensitivity midranges are candidates and you can choose whatever you want.

If you want more bass from the midrange then you need the midwoofer not
pure midrange, the Seas are good candidates, but I would probably be biased
and choose the PHL1340. I don't see this driver listed on those sites, but
e-speakers has the PHL1360 which is probably similar in design. The PHL treated
paper cones will have better high frequency SQ than Seas and be more flexible in higher frequency crossover points. You can probably do a test box with a ported
midrange design if you want to extract more bass. heh

Since you have a XLS402, do an experiment with the Dayton woofer to see if
it meets your expectations otherwise it's all guessing. Once you find the answer,
proceed to the next phase.

With LR8 filters, you can push crossover frequencies lower on the tweeter.
For example, I use a $25 PT2 planar at 1.7khz LR8, normally it is used at
>3khz with 2nd order, maybe 2.5khz 4th order, but with 8th order I can push it
lower. You won't have any issue with AC G3 or Fountek ribbon LR8 @ 2khz,
you can probably take them to 1.7khz.

Even if the tweeter is able to perform lower than 1.7khz, you may not like
the sound you hear. I have uber planars than are flat to 1.6khz, the manufacturer operates them at 1.2khz 2nd order, but I still prefer the sound with the LR8
near 2khz plus or minus a few hundred hertz.

Install 1A AGC inline fuses on your tweeters for protection. Ribbons are
uber sensitive, there has been reports of the ribbon element breaking
due to power on glitches so audio system power sequencing is important.
Ribbon are also sensitive to amplifier DC offset as it can tweak the ribbon if
there is a transient DC. Many people like to install a capacitor inline with the
ribbon tweeter to block DC as a safety measure. The fuse + cap wouldn't
be a bad idea to protect your investment.

Because it is easy to clip a low powered amplifier, I wouldn't feel comfortable
driving high end ribbons with low powered amplifiers, you may easily run
the amp into high distortion clipping.

12-06-2006, 09:03 PM
The main purpose of this thread is to determine whether or not a ribbon tweeter will sound awesome and compliment my system to the pinnacle of perfection. If the HDS will sound better, than im content with that. I've just heard people raving about ribbons and since I found a good deal, maybe theyd work for me and sound bounds better than conventional domes:D

The midrange does not need to reproduce anything on the low-end. It will be placed on a 24" baffle (560hz) so between 560-280 it will have a 6dB+ rise in efficiency due to both waves combining in phase. The baffle will cause a pretty severe rolloff after 280hz, and im working that into the design as an advantage to compliment my active crossovers. Im not looking for any more response below that, and am not going to limit my speaker choice with amplifier requirements. The W18E seems like an amazing driver and can do wonders with the right amount of power, I will have plenty for it:D If the tweeter requires a lot of power, than I will provide it, but with a driver with a 100dB+ sensitivity I believe Im going to reach diminishing returns when a $30 t-amp will work 95% as well.

Will the Fountek NeoCD2.0/AC G3 sound phenomenal crossed at 1.6khz w/ LR8s? I dont want my system to sound strained, and they will need to fit in with the design of the system.

12-07-2006, 12:09 PM

Ribbon, planar, horn, dome, etc., tweeter all have their own unique sonic
personality. People will prefer one technoloogy over another and the technology
implementation will be different amongst different brands. The good news is that
dome tweeters dominate the market and there are so many good ones to choose from. You almost can't go wrong. For ribbons, there is a few quality
products, for planars you have less to choose from. Cheap planars exist in the market place and these are really only good for line arrays, standalone they aren't as good as the others. Pro planars - there are three companies that I've found that make them, only one sells to DIY and this driver is uber expensive, IMO, the performance beats domes and the best ribbons.

What you have to do is audition the technologies to understand their sound personality, otherwise you are just guessing that the ribbon will beat the dome, etc. Dome have a dispersion advantage over ribbons and planars. Ribbons/planars have weak vertical dispersion so the best sound comes by
aiming the tweeter towards the listener's head. Ideally, a tilt and rotate mechanical design would be sweet. For instance, lets say you made a tweeter
and midrange box that sits on top of the woofer box, the top tweeter/mid box
would be great if you made a tilt and rotate mechanism so you can aim the
top box at the listening position - the sweet spot.

Ribbons and planars are great for line arrays as there is very little dome tweeter
choices on the market for low center to center driver spacing.

Nobody will be able to tell you which tweeter technology you will like, you
have to sample them to really know, akin to test driving cars before you buy.

If you buy a quality dome, ribbon or planar, it will perform well. Just accecpt the
sonic personality until you build your next project as each speaker you build will
be unique in it's own way. There is really no perfection.

If you don't need any bass from the midrange, then you can try to optimize the
design by seeking the pure midrange driver, maybe you can extract a little bit
more SQ if you choose the right one. There are alot of hybrid midranges on
the market where they combine midrange performance with woofer performance, ie the midwoofer.

Seas Excel are midwoofers. They usually give you nice bass performance but
because they use an exotic cone material, they have problems with higher
frequency performance. I have a Seas Excel W22 8" midwoofer and overal it's a nice sounding midwoofer, but you need a ~ 1.5khz 4th order crossover to filter out the 'sizzle sound' on the top end. With LR8, you can probably take it to 2khz. Not bad really. The smaller Seas Excels can go higher in crossover frequency.

Because their sensitivity is really low {byproduct of a midwoofer design}, you
need more power to drive them to their sweet spot. My Adcom 555 amp
200w/ch on the Seas Excel W22 is boring in sound. I need to bridge my Adcom
amp {600w bridged into 8 ohms} to get the driver to come alive and give me
some sonic nirvana.

On the other hand, if you don't need the bass output, then the PHL 'pure midranges' are just superior to the Seas product. PHL1120 is a high SQ
'pure midrange' driver with 97dB sensitivity.

Seas W18E is 88dB senstivity, that is 9dB lower than the PHL. That is a huge


1. Lets say that 200w drives that seas W18 to decent levels, the PHL would only
need about 25w to do the same SPL.

2. Lets say you want life-like dynamics from the sound, you connect the PHL
to a high powered bridged amplifier. Best kept secret in audio is to mate
high sensitivity to high headroom amplifiers for life-like sound levels. Lets say
you connect that Adcom in bridge mode to the PHL midrange, you will have
better musical dynamic performance than the lower sensitivity driver. To get
the Seas to do the same job as, the bridged Adcom would not be enough headroom. You would have to get a 5kw amp to get that same slam in sound.

If your woofer budget was higher and you have patients, I would try to
contact John at AE speakers.


He bought the Lambda woofer line and was building-to-order the Lambda
woofers. TD15X with faraday motor is about $450 a pair. These are the best
woofers for higher frequency application. The Dayton 15HF at $139 is hard to beat but the TD15X are very unique in SQ and design, worth every penny.
I don't know what happend to AE speakers, early in 2006 he partnered up
with someone to get the business going, the forum was active, then all of
a sudden the forum is not working and nobody has heard from them.. arg.....

Crossover Frequency
It's best to fine tune the crossover frequency when you have the finished product. For now you can plan on certain crossover frequencies, ie 1.6khz
LR8 for the ribbon tweeter, but because you have a DCX, I can guarantee that
you will be changing the crossover frequency alot as you fine tune the sound
by ear. Furthermore, the DCX is programmable, don't be like everyone else
who makes speakers - don't do what manufacturers do, don't do what other
DIY'ers do with loudspeaker design.

Do what I do
Harness the power of the digital crossover and program different settings
because you can. I have 12 different crossover settings for my budget line
array to extract all the potential from the loudspeaker. Each genre of music,
each song, your mood, the recording, etc., all these variables play a big role
and you can optimize your speaker by altering it's performance to compensate
for those variables. I can show you a concept idea on how to execute this later.

Here's how it works. I feel mellow so I recall program #5 in the DCX. I listen
to the sound at some SPL level. I analyze the sound for that moment and
then load program #4, then program #6, skewing down and up to find
the best settings for that moment in listening.

Lets say my friend comes over and he wants to head bang. I already know
that program #7 up to #12 is ideal so I load those until I get the sound perfect.

Why settle for one sound when you can create more ? That is the cool thing with
the DCX. You may create different programs with different settings, ie

a. crossover frequency
b. gain
c. EQ
d. delay

When you say that you will be using a 1.6khz crossover point, that is way too
generic to make it written in stone. You will be programming your system with
different variables and storing them in DCX memory if you want to exploit your
audio system to it's fullest potential.

On DIYaudio, one guy built a ribbon/PR170M0/Lambda TD loudspeaker. I can't find the thread, but I do have a pic on my
computer of his speaker. I think that recipe is ideal for you even though sourcing TD15 may be difficult or impossible.

The amp issue is really a non-issue. You can always experiment with different amplifiers to figure out
what is best for the design. If you have one 'reference' high powered amplifier like XLS402, you can use
it on the tweeters and mids to compare the sound and performance to the T-amps. There is always an
upgrade path here so don't worry about it. Worry more about driver selection and integration and the
DCX will make the process a peace of cake if you don't choose the best drivers, having LR8 capability will
compensate for some of the issues.

12-07-2006, 04:30 PM
I already purchased the Dayton Reference HF 15s from partsexpress last night:D $280 shipped for the pair, smokin deal!

Im going to try and take your guys advice on what midrange to use by trying out several drivers from madisound, and sending back the ones I dont like. I doubt the Seas W18Es will be hard to sell if I dont like them, and I may even keep them for another project.

What midranges would you recommend? I'd like to spend <$300 combined shipped on all my midranges I will be auditioning (I'd like to buy them all from the same place). The Audax PR170M0 comes to mind, along with the Peerless Exclusive line but im not sure which size driver has the best midrange performance.

I think Im going to just purchase the Ribbons and the Peerless and decide which I prefer, I could undoubtedly sell the ribbons without losing much money and I could just return the Peerless assuming I didnt damage them.

How do the Fountek NeoCD2.0s compare to the Aurum Cantus G3s? Theyre much cheaper, and I dont have the budget to audition several ribbons with my current budget.

What tips would you recommend for installing/testing the drivers and not aesthetically damaging them?

What measuring equipment would you recommend? The DEQ2496 + ECM8000 comes to mind.

Also, placement on the baffle is critical for minimizing diffraction amplitudes. Is there a mathematical formula for determining where to place the drivers on the baffle?

12-07-2006, 04:59 PM
What pro-planar do you speak of? The only one ive come across is the HI-VI RT2-PRO, with a 99dB sensitivity and goes for ~$180 over on partsexpress

12-07-2006, 06:40 PM
PR170M0 is a great snag for the money. Rumor says it was designed by the
founder of PHL audio when he was working at Audax. The PHL1120 cost alot
more, it has more xmax, higher power handing, but it really resembles the PR17
very close in sound. It would be very difficult to tell the two apart soundwise. You
should only consider the PHL if you want to push your loudpeaker to higher SPL
limits. PHL1340 is a midwoofer that competes with Seas W22. While it won't
have the bass performance as W22, the PHL top end performance rules.

E-speakers has the 1360. I haven't tried it but it seems to resemble the 1340.
Many PHL drivers listed on their site are generic as they do alot of OEM work.
E-speakers was sourcing a 1240 driver with phase plug. 1240 is the 16 ohm
version of 1340. I don't think that plug was a stock item, maybe a special order?
I'm using PHL for my high end build, the overal sound was better than
Focal and Seas when you look a the big picture. Paper treated cones have
superior sound. Kevlar, magnesium and metal cones are inferior in spite
that manufacturers try to market them as being superior to old school paper.
PHL also does rear cone treatments, a special order if you buy bulk. Ie, if
you specified a 1121 vs. 1120, the number 1 on the end is the code for rear
cone treatment. I ordered a bunch of 2451's for my future array, this is a 100dB
8" pure midrange that really kicks some butt if you have a high output tweeter
like pro-planar or horm tweeter. A regular planar, ribbon or dome can not keep
up with it's SPL ability. If you want a killer 10" pure midrange, PHL3450.. 101dB
sensitivity. A monster mid. It also requires an uber tweeter to keep up.

Word on the street says that the old Fountek ribbons offers great sound just like
the AC ribbons. The newer Founteks though, are not aluminum ribbon element,
they are of some composite material, but I haven't seen any bad reviews on the
newer design.

It's pointless to do technical measurements because it really doesn't solve
the root issue -> "Do you like the sound?" ... Will measurements tell you if you like
the sound or will doing listening tests tell you more? I personally hook up
the individual drivers and play around with them to understand their capabilities.

Get your tweeter candidates and hook one up to the amplifier and set your
crossover to a ballpark 'safe' crossover point. For example, set your tweeter
crossover to LR8 3khz. Install the inline fuse {1 amp AGC} to protect the tweeter.
Play some tunes and just listen to the tweeter. As you listen to the music,
slowly turn the crossover knob and lower the crossover frequency and note
the effect it has on the sound. Keep the crossover. Try to hit the lowest
recommended crossover range, in this case lets say ~1.5khz is a good low
target to test. Skew between 1.5khz and 2khz to see what frequency is
more pleasing to the ear. I prefer 2khz plus or minus 300hz. For uber crazy
SPL, adjust it closer to 3khz to prevent tweeter damage. For very low SPL,
you can go under 1.5khz. I have my PT2 planars set at 1.2khz for very low
listening levels, up to 3khz for headbanging SPL.

To test the midranges you can do many types of tests. You can test the
driver 'as is', out of the box. place the driver on the table tilted at you
and just play music full range to see what it sounds like out of the box.
As you raise SPL, cone excursion rises as there is alot of bass content in the
music and you can damage the driver so only do this test at lower SPL.
This gives you an ideal on what the driver sounds like 'as is'. To do high SPL
tests, high pass the driver. Select 100hz and work your way up to maybe 300hz
to keep cone excursion low while allowing more SPL. Listen to the driver at high
SPL and notice the distortion manifest. You should hear cone breakup modes
and kevlar, magnesium, metal, etc., coned drivers will start to sound pretty bad.
You may notice that treated paper coned drivers sound more pleasing. This gives
you an idea on what these cone materials do or what they don't do. - lol

Since you won't run the midrange without a low pass filter, but doing the above
test is nice to do to see what the driver does, do the realistic test with high pass
and low pass filter enabled {bandpass}. This is a representation of how the driver will work. What you will notice is a lack of top end as the high frequencies
are not being attenuated by the crossover and cone breakup modes aren't being
manifested as much. Tweak the low pass crossover frequency to understand
where the nasty sound starts to manifest and make a mental note for each driver
you test.

For example, my W22 will sound bad above 2khz with 4th order. My PHL
sounds great full range. What does that tell me ? It tells me that the Seas Excel
is really picky and the crossover frequency chosen is critical for best SQ. PHL on
the other hand, tells that I can run the driver full range and not be offended by
the sound, therefore any low pass frequency I choose will work well and I can
now place all my attention on the tweeter and where does it work best? Set
the crossover to where the tweeter works best and that is also the default
setting for the midrange since it is not picky.

If you have a finicky tweeter & midrange, then you need to find one crossover
point that will work with both drivers.

You are better off designing the loudspeaker for proper driver synergy and
human interfacing synergy :eek: :)

Determine the primary listening position, ie standing up? sitting down? etc.
Place the drivers so they are aligned with your head, so if you were to
look at your speaker, you are staring right at the tweeter and the midrange
should be right under the tweeter with minimal gap. If you have to look way
up to see the tweeter, then it's too high. If you have to look down at the tweeter, it's too low. If you made a tilt mechanism, problem solved for any
listening position.

Next, since the woofer will operate into the low midrange region, somewhere
in the 300hz - 500hz range, you want good midrange/woofer synergy. Place
the woofer close to the midrange vs. placing the woofer down on the bottom
like you see in many other designs. This will give you seemless integration
from tweeter to mid to woofer without any major gaps of distance.

If you want to make an open baffle woofer design then obviously you need
a wide baffle and the design starts to look fugly. You will have to figure out
what ratios you prefer.

Before you finalize any design, have you really determined that you want open
baffle design or are you listening too much to those dummies at DIYaudio ?:laugh:

If you are unsure, make a test box. Make a deep test box for your midrange
and test it in a sealed enclosure with alot of loose polyfill inside. This will
keep SQ high if the box is very deep. If you want to improve SQ more,
use loose fiberglass insulation inside {pink stuff, etc}, but it can make you itch.
Partsexpress Acoustastuf is esoteric polyfill, it is more dense than Walmart
polyfil but alot more expensive.

Once you are done with the sealed box listening test, destroy the box
and remove the back and sides and do your OB test. Which implementation
did you like ? Sealed box or OB ? Use cheap particle board or chipboard for
your test boxes.

Do the same experiment with your Dayton 15 woofers. Make a ported box,
in spite that you will have a seperate subwoofer, a ported box can boost
performance {more on that later}. I would probably see if I can tune the box
in the 35hz range, no less. Do some ported box listening tests. When done,
plug the hole and now you have a big sealed box. Do another sealed box
listening test. Last, destroy your box and do an OB listening test. Which one of
three did you like ?

Ported boxes can increase the SQ of wideband woofers. Here's how. As you know, woofer cone excursion rises in sealed boxes playing bass, but in ported
boxes, cone excursion is less near port tuning not to mention the ported box is
just more efficient over sealed. If you ask the woofer to play higher frequencies
AND if cone excursion is high, you get modulation distortion. The sound
you hear is similar to the sound you hear if you talked right next to a spinning
fan blade. Your voice modulates. A woofer with high excursion playing wideband
will modulate the lower midrange and sound bad. So.... the trick is to keep
cone excursion low. You can operate the woofer at reduced SPL to keep low
frequency excursion low. You can raise the high pass crossover to keep excursion
low, but that kinda stinks, why have a 15" woofer if you can't crank it up with
high SQ ? The solution is to make a ported box so when you do crank it, cone
excursion is less near port tuning, you get mad bass output and high frequency SQ is better than the sealed box.

I've done these tests with my Lambda Apollo woofers. I was 100% convinced
that a sealed box is best for SQ based on industry stereo type, but I noticed
that cone excursion was too high and midrange modulation was making the sound unsweet. I made a ported box tuned to 35hz and not only did I get
more bass output, cone excursion was less and less audible modulation distortion. /sweet

If you do an OB design and operate that woofer into the 300-500hz range,
I think you will run into alot of problems at higher SPL with midrange modulation
distortion as OB designs require an EQ to boost the bass response because
OB's lack decent bass output. Using an EQ to boost cone excursion seems very
counter productive to me. You should really make the test boxes to make
sure you have the right design for your listening habits. Verify first by making
the test boxes, then design the loudspeaker based on the data you gathered.