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Old 7th February 2008, 01:57 AM   #31
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The bad news is that the driver I used in my Unity clone, the aurasound nsw2 "whisper" is no longer available.
The good news is that Peerless is selling a two inch driver with thiele small parameters which are virtually identical, but a LITTLE bit better. John Sheerin and I both had a b1tch of a time getting the midranges to play high enough, and this little Peerless driver is a compelling candidate. The Aurasound Whisper gave up at about 772hz, but the Peerless should be good for 888hz.

It's so close that it should practically be a drop-in replacement in my design.

I put the thiele small parameters online in my spreadsheet:
http://spreadsheets.google.com/ccc?k...eZHPciOw&pli=1

I took the parameters from John Krutke. His measurements are usually more reliable than the manufacturers, who often candy-coat the data:
http://www.zaphaudio.com/tidbits/Peerless-830970-TS.gif

You can buy it here:
http://www.madisound.com/catalog/pro...oducts_id=8267
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Old 9th February 2008, 03:06 PM   #32
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Awesome news! Thanks for the update. I'm thinking of changing my system again. I have the Peerless 4" PPB cones in 1.4 Liter enclosures on my dash with the LPG neo Aluminums and JL Audio 8IB4s as midbass right now. The time alignment is easily dealt with (for one passenger) but the imaging is killing me. The imaging is similar to that of headphones... none.

Are you still using the BMS compression driver or have you tried the Alpine XT19?

I'm thinking of buying a pair of 18sound 6ND430 drivers because of my failed attempt to fabricate perfect door panels. Fitting 8" woofers with a 3.75" depth is almost impossible in the Subaru Impreza platform front doors.

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Old 9th February 2008, 08:05 PM   #33
GM is offline GM  United States
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Quote:
Originally posted by mefistofelez
Dear Greg:

The specifications you are mentioning were for the Audax, not the Real McCoy, correct?

I am working towards a goal of a conically-shaped horn, but my efforts are being slowed by almost constant travel. Did you see my latest attempt: http://people.qualcomm.com/kalousek/index.htm ?

Greets!

Hmm, sorry , I missed this at the time for whatever reason..........

Correct.

The link timed out, so not sure if it's one you PM'd me or not. So, any updates or is your jetsetting lifestyle still keeping you too busy?

GM
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Old 2nd December 2008, 01:42 PM   #34
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Quote:
Originally posted by omarmipi
Sorry for the slow learning curve... I guess my Audax midrange drivers are only covering 1 octave because of the low FS.
Did you have any luck with this project?

You may have noticed that I re-vived my Unity project. I'm about to purchase a few more midranges for testing purposes, and the Audax which you are using is one of the candidates. The supply is nearly exhausted, but Madisound still has it on their sale page at the moment.

http://www.madisound.com/catalog/pro...roducts_id=101
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Old 17th October 2009, 12:03 AM   #35
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I've been messing with Unity horns for close to three years now, and I've managed to purchase a pile of midrange drivers that work on Unity horns. I have the Misco drivers which I believe were used in the Lambda Unity horns, as well as a newer driver from Misco which is as good or better.

Click the image to open in full size.
Misco JC5RTF-B, KCN5FD and TB W4-1805S

One thing that we have ignored in this discussion is frequency response and distortion. The woofers in a Unity horn require a very VERY specific set of Thiele Small parameters. Basically it needs a VERY high FS, and a VERY low QES.

What you end up with is a woofer that has an extreeeeeemely light cone, and an accordian surround. If you add even a fraction of a gram to the cone or the surround, it drives down the FS too low, and then it doesn't work for a Unity horn! It's as simple as that - if the specs on the midrange are wrong, your Unity horn isn't going to work.

Click the image to open in full size.

Because the Unity mids require a cone which is astonishingly light, and an accordian surround, we end up with a woofer that looks a lot like something you'd find on an old CRT TV. Basically a giant version of one of those cone tweeters you see in speakers from the 70s.

One interesting alternative is the Tang Band W4-1805S. Tang Band makes a lot of great drivers, but only TWO of them will work on a Unity horn. The reason that all the others won't work is that their cones are too heavy, which drives down the FS too low, and the QES is too high. This particular woofer is an exception. It has the right specs for a Unity horn, AND it has an underhung motor with very low distortion. I haven't measured it's distortion yet, but it's audibly cleaner than the Misco.

(That isn't a knock on the Misco; it's a MUCH less expensive driver. Misco offers exceptional performance, and the TB gives you all that and more, for an additional cost.)

Click the image to open in full size.

Parts-Express.com:*Tang Band W4-1805S 4" Neodymium Midrange Driver | Tang Band W4-1805S 4" midrange tb speakers neodymium driver line array point source midrange home theater computer speaker center channel set tube amplifier cone mid

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Old 17th October 2009, 12:44 AM   #36
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You say you want low low Qes and very high Fs.
So you are asking for, basically whats known as
Efficiency Bandwidth Product? Is that correct???
Fs/Qes=EBP

But is BL/MMS possibly the better figure of merit?
Or is this all the same as EBP except for L of the
coil overhang? And you don't want any overhang...

What I mean, if the motor can handle the extra
weight, does it matter Fs is a bit low? And if the
motor ain't powerful enough to move the cone's
weight, does it really help that Fs may be sprung
moderately high?

What do you think of the Galaxy Hotspot and
the Neodymium version of the same? Fs a little
low (but higher than your Tang Band, and half
the price). But then again, backs of either driver
aren't yet cupped, so how does one compare???
Cupping them should raise Qms, Fs, and EBP.
But no change whatsoever to Qes or BL/MMS.

Galaxy 5" drivers should perhaps not be overlooked?
http://www.parts-express.com/pe/show...number=290-015

DeltaPro8 also has murderously high EBP (308) for
a driver of its size, and will only go up when cupped.
But perhaps bigger than you were looking on a unity.
Unfortunately, its not cheap.

Last edited by kenpeter; 17th October 2009 at 01:04 AM.
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Old 17th October 2009, 01:06 AM   #37
tinitus is offline tinitus  Europe
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I may have suggested it before
Unity line source
Only, expencive even with cheap drivers
Attached Images
File Type: jpg unity line.JPG (15.6 KB, 285 views)

Last edited by tinitus; 17th October 2009 at 01:13 AM.
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Old 17th October 2009, 01:38 AM   #38
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Quote:
Originally Posted by kenpeter View Post
You say you want low low Qes and very high Fs.
So you are asking for, basically whats known as
Efficiency Bandwidth Product? Is that correct???
Fs/Qes=EBP

But is BL/MMS possibly the better figure of merit?
Or is this all the same as EBP except for L of the
coil overhang? And you don't want any overhang...

What I mean, if the motor can handle the extra
weight, does it matter Fs is a bit low? And if the
motor ain't powerful enough to move the cone's
weight, does it really help that Fs may be sprung
moderately high?

What do you think of the Galaxy Hotspot and
the Neodymium version of the same? Fs a little
low (but higher than your Tang Band, and half
the price). But then again, backs of either driver
aren't yet cupped, so how does one compare???
Cupping them should raise Qms, Fs, and EBP.
But no change whatsoever to Qes or BL/MMS.

Galaxy 5" drivers should perhaps not be overlooked?
Parts-Express.com:*Galaxy Audio S5C160-8 5" Full Range Driver | transducer sound monitor hot spot galaxy full range driver full range drivers driver audio audi

<snip>
I've studied the Unity horn for close to a decade, and the comments that GM made in this thread were one of the "Eureka" moments when I began to understand how all these pieces fit together in a Unity.

It's not just that we need a high EBP; we need a very SPECIFIC EBP.

As GM noted, here's the formula:

2 * FS / QES = 500

GM or Danley might come in and school me, but here's how I understand this:

The EBP will dictate the upper and the lower limit of our midranges on the horn. It works out to about one octave on either side of (EBP x 2). So if we want to get the mids up to 1khz, our lower limit is about 250hz.

Here's the EBP and upper limits for various woofers:

  • Misco KCN5FD (only sold in quantity) - 384 / 1538hz
  • Tangband W2-852SH ($15) - 356 / 1422hz
  • Tang Band W4-1805S ($69) - 275 / 1100hz
  • Misco JC5RTF-B (only sold in quantity) 250 / 1khz
  • Galaxy Audio S5N-8 ($49) - 197 / 788hz

Here are my thoughts on the ones you suggested. I have the Galaxy Audio, and it's parameters aren't appropriate for a Unity horn. You basically can't get it to play high enough. Getting it past 800hz will be a struggle. John Sheerin evaluated the ferrite version for his Unities, and discarded them also.

The Misco JC5RTF-B is clearly the easiest one to work with, has the right parameters, and you don't have to hassle with sealing the back.

The TangBand W2 sounds a bit "cleaner" to my ears. Is it the underhung motor? I dunno. I haven't measured it's distortion, but it sounds very good. It's efficiency is much higher than you might think too; a pair of the W2s nearly match the efficiency of the Misco 5".

The TangBand W4 is clearly the cleanest sounding of the bunch. It is also the most expensive.

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Old 17th October 2009, 01:40 AM   #39
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Quote:
Originally Posted by tinitus View Post
I may have suggested it before
Unity line source
Only, expencive even with cheap drivers
Take a look at the Synergy Horn patent.

Both the Unity horn and the Synergy Horn are arrays. In fact, the lab sub is an array too.

Danley is subdiving a single woofer into multiple unique parts, then arraying them on a horn. The midranges and the woofers on the Synergy, Unity, and Lab horns are arrays.

It isn't a coincidence that Danley's new designs, like the new tapped horns and the Paraline use multiple elements. Danley's commercial offerings are quietly solving the problems with conventional arrays.
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Old 17th October 2009, 03:00 AM   #40
bjorno is offline bjorno  Sweden
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Quote:
Originally Posted by Patrick Bateman View Post
[font=verdana]
..It's not just that we need a high EBP; we need a very SPECIFIC EBP..
.
Hi, I don't think you should mix EPB= fs/Qes with the expression 2*fs/Qes. although they are related: See the picture.

b
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