10" on the bottom

bubba966 · « **Reply #20 on:** 30 Jan 2004, 09:05 am »

I heard the 10" Adire XBL^2 driver in the CSS sub at VSAC in October. And it certainly wasn't boomy. Just tight, clean bass. And a good deal of it from such a small driver in a little sealed cube.

Having experienced that driver I don't see why it wouldn't be acceptable for handling low end duties in an 1801 enclosure. But, I'm not a speaker designer, and my experience with the 1801 is very limited.

Dave, maybe you wouldn't care for it in your speaks. But I don't think they'd be terribly dissappointing if you did end up not liking them. I honestly think that someone should give them a try in this situation.

David Ellis · « **Reply #21 on:** 30 Jan 2004, 03:44 pm »

Sensitivity...

When asked about the Adire drivers my answer could have been more terse. I could have responded with something like, "It ain't sensitive enough". Unfortunatly my answer begged further questions. Whew, this is going to get long again.

The impact of this is thermal compression in the voice coil. The voice coil gets hot when subjected to the friction of flowing electrons. The heat/friction incurred is directly proportional to the quantity of electrons flowing through the voice coil. The very low sensitivity of the 82db/watt 10" Brahma requires a very high number of electrons/heat to produce the same SPL when compared to an 87db/watt SEAS woofer.

I do NOT believe this is overly critical in the subwoofer region. This is simply because the rise and fall time is very slow. The required driver "speed" for bass is very low. Further, a little thermal compression will likley have little impact.

****
I am working through these issues mathematically, but have not finished yet. I am fairly confident the formula for acceleration in G- Force is G=F^2 D where F = Frequency and D = Displacement. When I finish this study, I'll post the implications.
****

I DO believe sensitivity has profound effects as frequency progressively moves upward. This is simply because the rise and fall time is very fast. Thermal compression will have significant impact in the tweeter region.

The WOOFER predicates the system sensitivity. An 82db tweeter just won't get the job done IMO. Futher, and 82db speaker requires roughly 1 2/3rds more juice than an 87db speaker. This translates to more amplifier heat, distortion.

While there is more to dynamics than sensitivity and heat, I feels very safe making the assertion that "Sensitivity is directly related to dynamics".

The slippery slope on this issue ranges from big Rock-n-Roll monitors at 95db at 16 ohms to hifi speakers to Hifi monitors at 84db at 4 ohms.

The discussion of thermal

Spiders...

Quote

How are the spiders adding to the distortion?

The spider is the primary mechanical restoring force for the cone. It has spring and dampening. There is also some effect from the surround.

Those with sufficient detail on the subject have a price ($) for their time. I didn't ask this specific question during my last visit to CES, but I am sure this is a fair question for such a gentlemen at CES.

Most guys attend CES with the sole purpose of listening to cool stuff. I believe it's MUCH more gratifying/beneficial to tap the huge brains and experience of these industry guys.

Quote

I thought linearity of the motor was the driving factor in long-throw woofers, which is where the Adire motor structure is supposed to be an advantage.

Yes, on the electrical side.

I have not heard the Brahma. However, I did hear a few big $ linear motor long throw woofers at CES 2002 in the $600-$1000 zone. As a bass driver the SCC300 sounded better than any of them. I can only attribute this to Sensitivity, Spider, and Stiff cone issues. There are likely many other factors that I am totally unaware of.

Using the L26 or W26 in this 3 way NOT perfect. Nobody makes the perfect 10" woofer IMO. Yes, the X-Max is slightly low, but still respectable. IMO, the L26 or W26 10" woofers are the best available today for the bottom end of a 3 way.

If I wanted to build a a 10" subwoofer, the 10" brahma would be a better choice.

dayneger · « **Reply #22 on:** 30 Jan 2004, 04:39 pm »

Hi Dave,

Just a quick comment--I'm not referring to the Brahma--that's a totally different driver series optimized for horrendous SPL in cars.

Quote

I could have responded with something like, "It ain't sensitive enough".

But you didn't, because you ain't a redneck, right?

The CES site shows these numbers for their OEM driver:

Quote

Parameters are as follows: Re: 3.3 ohm, Le:0.9 mH, fs: 27 Hz, Qms: 3.4, Qes: .48, Qts: .43, Mms: 70.89, Cms: .48 mm/N, Vas 79.69, Sd: 345 cm^2, BL: 9.09, Pmax: 300 watts, Xmax:18 mm one way, Efficiency: 87.1

So 87 db like the SEAS, not 82.

Cheers,

Dayne

David Ellis · « **Reply #23 on:** 30 Jan 2004, 05:20 pm »

I managed to find the factory specs for the Brahma 10" yesterday. The task was a little arduous. I can't find them today. There are a few dead links.

I am certain the 87db quote from the CES site is based on 2.83 volts (not watts). At 3.3 ohms this seems about right.

//

Ah I found it:

http://www.adireaudio.com/mobile_audio/drivers/brahma_series.htm

82.3db/watt

And they list a lower dcr too. This certainly explains the extreme desparity between 87db and 82db.

randog · « **Reply #24 on:** 30 Jan 2004, 05:53 pm »

Dave, like Dayne said, these are two different animals... like Monkeys and Dogs...

I can understand the confusion, tho. I went to the Adire website and could find nothing about their 10" sub for home audio. Yet Kevin of DIY and Brian of RAD are both using them in their small box designs.

Dayne, can you provide a link?

Randy

David Ellis · « **Reply #25 on:** 30 Jan 2004, 06:38 pm »

Hm, it's be nice if Adire had their information published. It might have saved me a bunch of typing. Then, probably not.

If folks are using this driver for deep bass in a small cabinet then my remarks remain true.

Increased cabinet size is directly proportional to increased sensitivity and increased bass depth.

Hence, deep bass requires a large cabinet unless sensitivity is sacrificed.

Sacrificing sensitivity enables deep bass in a small cabinet. This is likely the approach Adire used.

Dave

bubba966 · « **Reply #26 on:** 30 Jan 2004, 09:32 pm »

Dave,

Here's a page showing the specs of the driver than Dayne & I have been talking about. http://www.creativesound.ca/details.php?model=SX10

I'm not sure if the 10" XBL^2 driver that DIYCable is getting from Adire is the same OEM driver or not.

David Ellis · « **Reply #27 on:** 30 Jan 2004, 09:47 pm »

Okay, this helps clarify matters.

My previous comments apply, and I am not willing to build a 3.3 ohm speaker.

smithsonga · « **Reply #28 on:** 17 Feb 2004, 12:40 pm »

Dave-

Other than the improvements in midrange, what are your expectations based on the tuning etc...on how much more low freq you will get with the 10"? 10 more hz?

Thx
Jim

David Ellis · « **Reply #29 on:** 17 Feb 2004, 06:28 pm »

Jim,

The difference in bass impact isn't really about the F3 or F10. While the F10 using the W26 or L26 will be about 15hz lower than the 1801, I think there are other issues more important. Probably the most prevalent L26/W26 advantage is the voice coil configuration.

The voice coil on these woofers is bigger (2" diameter) and has superior heat-sink ability. Dissipating heat quickly in the voice coil is critical to resolution. The degree of heat dissipation is a result of many factors. Size is certainly one of them. The nice big 2" voice coil is a big boon for bass resolution. Another factor is the voice coils direct connection with the anodized aluminum former. The result is a nice big heat sink on both sides of the voice coil. The wire side will breath to open air, and the former side is well connected to the voice coil.

salva · « **Reply #30 on:** 18 Feb 2004, 09:32 pm »

Hi, I want to thank publically Ellis, for its patience and understanding.

I had been all over the place, looking for a DIY kit, and I have to say that Dave's 1801 is the most down to earth. Plus Dave is a very good guy.

While, I'm still waiting to finish my deal with Dave, I'm sure now that I will not be disapointed.

I learned today that he has leave town for a couple of weeks for a medical procedure. I Hope that all will be OK for him.

Salva

salva · « **Reply #31 on:** 19 Feb 2004, 07:57 am »

ooopssss.

I Wanted to start a thread, but did a post. Sorry

Salva

David Ellis · « **Reply #32 on:** 19 Feb 2004, 01:15 pm »

I'll be gone for two weeks... details in another thread.

Dave

totti1965 · « **Reply #33 on:** 9 Mar 2004, 10:42 am »

Hi Emilio,

I hope that everything is fine with dave and his eye operation is not to serious....

I am from Germany and I am waiting for my own 1801 `s that I have ordered in dezember 2002.

I would be glad, if you would send me 4 or 5 pics in high resulution of your 1801 made by dave, wich are so beautifull and now not longer aviable in the galery of audiocircle....

Many thanks,

Yours,

Thorsten

Figo · « **Reply #34 on:** 9 Mar 2004, 11:48 am »

http://www.audiocircle.com/index.php?action=gallery;area=browse;album=15

works for me

totti1965 · « **Reply #35 on:** 9 Mar 2004, 11:56 am »

thx, I didn´t find it.....

but even would be glad, if emilio could send me 3 or 4 pics in 500 kb resolution......

smithsonga · « **Reply #36 on:** 17 May 2005, 11:59 pm »

David-

Any update on the 3-way project? Decide which bass driver? Timing?

inquiring minds would like to know..........

Thx
Jim

JoshK · « **Reply #37 on:** 18 May 2005, 12:51 am »

Have you examined the TC Sound 10"? I know you probably want to avoid direct head on competition with friendly foe (Salk Sound) who uses said driver, but I have heard many good things about said drivers from TC Sound.

David Ellis · « **Reply #38 on:** 18 May 2005, 05:38 pm »

Well,

There are a couple thoughts viable.

First, Jim Salk and I aren't necessarily in "competition". Cooperation moving towards partnership is the realm of our relationship. We happily share ideas, experience and parts where applicable.

Second, Jim's 10" might be the woofer I finally use, but the 10" project will be delayed. Initially I planned to have TC Sounds build a 10" woofer for me. It would have a light cone (higher sensitivity), underhung motor ( extremely low distortion ),and a few other nick-nacks. This probably won't happen for reasons explained below. Primarily, the 12" SCC300 is in short-supply, and will not be renewed.

Since I am more enthusiastic about a 12" project than a 10" project, the first woofer from TC Sounds made for me will be a 12" TC Sounds unit.

Jim's woofer is a very solid unit, but I would prefer a higher sensitivity woofer intended for a slightly larger cabinet. The result is less thermal compression. It would have a higher F3 than Jim's, and work in a sealed cabinet. However, all of this is simply pipe-dream conjecture at this point. Jim's 10" woofer remains a very good sounding unit. The sensitivity is a bit low, but this seems to have little impact in the overall thermal compression realm in the midrange and highs. These were on-par with a more sensitive NAO loudspeaker midrange/highs IMO. But... the 10" is on the distant back burner, and will happen after the 12" 3-way.

On the extreme up-side

... There were some personnel changes at TC Sounds and my woofer(intially a 10" driver) development that began in Oct 2004 got dropped/lost

. This is actually good news, and appears to be a blessing in disguise

. During this time the 12" SCC300 ( www.soniccraft.com ) sel-out started

. Also, during this time some new cone materials and surround materials were ordained at TC Sounds

. The result should be the best sounding 12" woofer on the planet

. From an objective perspective this should happen, but... the proof is in the music

.

I have often found bad circumstances very positive... in retrospect. Life is a bit strange this way. I consider myself undeservedly blessed in so many ways.

David Ellis · « **Reply #39 on:** 18 May 2005, 05:38 pm »