shorting rings?

what is the purpose of a shorting ring in a subwoofer and what material is better for them to be made out of?

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The shorting ring is to reduce the inductance of the voice coil, improving transient response, and the better the conductor, the better the shorting ring.

Aluminum and copper are common materials, and in theory, silver would work the very best, (as it is the best conductor known) but it would be quite an expensive option.

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It all reminds me of something that Molière once said to Guy de Maupassant at a café in Vienna: "That's nice. You should write it down."

ok thanks, last question, how would you describe transient response?

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Transient response... You may have to follow a few links in there, but that'll get you there!

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It all reminds me of something that Molière once said to Guy de Maupassant at a café in Vienna: "That's nice. You should write it down."

so your transient response is basically anything that isn't 100% at rest or maxed out. the in-between time of the cone being completely in or out? am i close? way off? i think i get it mentally but it is hard to describe in words.

basically, a shorting reduces the inductance of the voice coil while the coil is moving and the inductance is electrical feedback caused by the coil moving in and out of a magnetic field, right?

oh, and thanks Haemphyst for being the only one that knows anything.

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1: I assure you I am not the only one that knows anything on this forum, but thanks, anyway...

2: When you lower the inductance of the voice coil at Fs, the amplifier can a) make more power at that frequency, and b) exert better control over the voice coil at that frequency. These are both good things.

3: This is the difficult answer. Transient respose is both a physical proof or number, and a ... listener impression. Transient response is generally accepted as "how fast can a given driver respond to this input signal?" LARGE drivers, not generally driven over 80 to 100Hz, it REALLY isn't as important as (especially, IMO) a mid-bass driver, required to respond to frequencies as high as a few kHz. In my car, they are only taken to 250Hz, but my mids are "shorting ring equipped" as well. Vifa mids, with carbon/Kevlar cones, they are LITERALLY the only two of these specific drivers IN THE WORLD. They were custom ordered from Vifa by a driver engineer (a personal friend of mine) at Harmon International for a center channel HT speaker in the Revel line, that never materialized. (BTW... Three way, with 600+ watts per side in my doors... Here's the thread, if you want to see the specifics of my system...)

Continuing... Physical in the fact that the amp can have better control (at least mathematically) over the voice coil, and the "listener impression" part means, well... it sounds "faster". How good is the slam? The Adires in my door contain have shorting rings, and I can tell you for SURE that they are the VERY most accurate mid-bass drivers I have ever had in my doors, and I was at one time a HUGE fan of the Morel MW-162. The Morel was a 6 inch driver with a 3", respectably long throw voice coil (I want to say +/- 4mm or so), with FANTASTIC transient response - the mid-bass slam was nothing short of "live", and the Adires smack 'em down. There are several members on the board here, that have heard my system, and the reviews have been... well... "ego boosting".

When you have a LARGE diameter voice coil, like the Morel has, with but a few turns IN the magnetic field, you will always end up with a low inductance. When you reduce the VC diameter, and immerse more turns in the field to improve efficiency, your inductance will go up, destroying your transient response. This is why you won't see many "high-end" 6" drivers out there. I choose (ALWAYS) non-off-the-shelf drivers for this very reason.

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It all reminds me of something that Molière once said to Guy de Maupassant at a café in Vienna: "That's nice. You should write it down."

https://www.the12volt.com/installbay/forum_posts.asp~TID~64602~PN~1~m~k#post

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haemphyst wrote:

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When you have a LARGE diameter voice coil, like the Morel has, with but a few turns IN the magnetic field, you will always end up with a low inductance. When you reduce the VC diameter, and immerse more turns in the field to improve efficiency, your inductance will go up, destroying your transient response. This is why you won't see many "high-end" 6" drivers out there. I choose (ALWAYS) non-off-the-shelf drivers for this very reason.

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thats interesting, so you are saying it is basically a balance between low inductance and efficiency, and that generally, drivers with a low(er) efficiency will sound more accurate because of the low inductance. and also you are saying that a shorting ring isnt really that important in subwoofers. i guess i can understand how that can be true because sub bass isnt as directional as a mid, so if the sub sounds a little slow it should still sound fine as long as the mids are on point and blended well with the subs.

i would love to get my hands on a set of adire mids and replace my diamond hex 6.5's even though everybody says they are really good speakers and i should stay with them, i really just want to hear the difference.

also, thanks DYohn, that was a good read and i feel a little bit smarter now.

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bump

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I thought you were done... My apologies.

What else did you need answered?

You're pretty close with your analysis, except that the low inductance really doesn't have anything to do with the efficiency. Lower inductance improves the speed of the diaphragm, not necessarily the output.

I was a Morel fan, as stated earlier, but the difference between the Adire and the Morel was literally day and night. SO much faster and SO much more linear, if you can find a set, they are WELL worth the PITA installing them. Mpyre bought the tech, maybe you can find some of those...

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It all reminds me of something that Molière once said to Guy de Maupassant at a café in Vienna: "That's nice. You should write it down."

thanks for all of the information, i really appreciate you taking the time to type all of that. i pretty much get it as far as im going to without getting into some math so really i have nothing more to ask, i just wanted to see how close to the truth i was. i know you cant get the adires anymore and mpyres are really hard to find too for some reason. i guess they must not be selling well or something because i can only find them on ebay and only from 1 guy who cant sell them. i sent him a question asking him if they had shorting ring so i'll see what he says and i might end up buying them.
i really want to get 2 sets and put 1 in my truck and put the other in a HT setup with the morel MDT 30-s tweeters and a soundsplinter RL-S 12 for the bass. i think it would sound pretty BA

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i just thought of another question. when you are looking at the specs for any particular speaker, are there any specs that will indicate if a speaker has high or low inductance?

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soundnsecurity wrote:

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i just thought of another question. when you are looking at the specs for any particular speaker, are there any specs that will indicate if a speaker has high or low inductance?

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The inductance value is listed as Le and is given in milihenries.  This is generally per voice coil.

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DYohn] wrote:

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soundnsecurity wrote:

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i just thought of another question. when you are looking at the specs for any particular speaker, are there any specs that will indicate if a speaker has high or low inductance?

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The inductance value is listed as Le and is given in milihenries.   This is generally per voice coil.

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Also note that inductance is generally rated at 1kHz.

I also want to point out that the use of shorting rings doesn't necessarily mean inductance will be controlled within the pass band of the driver. When I worked at Adire Audio I saw a study conducted by David Hyre, who has his doctorate based around magnetics, which showed that it must be applied correctly to obtain beneficial results. We saw that many using them weren't doing it correctly and in some cases their use was a hindrance.

DYohn] wrote:

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https://www.the12volt.com/installbay/forum_posts.asp~TID~64602~PN~1~m~k#post

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For post number two of that thread, see here:

https://www.diycable.com/main/pdf/WooferSpeed.pdf

DYohn] wrote:

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soundnsecurity wrote:

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i just thought of another question. when you are looking at the specs for any particular speaker, are there any specs that will indicate if a speaker has high or low inductance?

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The inductance value is listed as Le and is given in milihenries.  This is generally per voice coil.

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ok, does anyone know if 0.005 is the same Le as the adire extremis mids? im trying to compare the mpyre mids to the adire mids.

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soundnsecurity wrote:

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DYohn] wrote:

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soundnsecurity wrote:

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i just thought of another question. when you are looking at the specs for any particular speaker, are there any specs that will indicate if a speaker has high or low inductance?

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The inductance value is listed as Le and is given in milihenries.� This is generally per voice coil.

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ok, does anyone know if 0.005 is the same Le as the adire extremis mids? im trying to compare the mpyre mids to the adire mids.

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They use the exact same motor and therefore it will be identical. The only difference between the two is the cone material used. I will be installing the Mpyre mids in my car on monday hopefully.

Steven Kephart wrote:

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soundnsecurity wrote:

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DYohn] wrote:

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soundnsecurity wrote:

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i just thought of another question. when you are looking at the specs for any particular speaker, are there any specs that will indicate if a speaker has high or low inductance?

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The inductance value is listed as Le and is given in milihenries.� This is generally per voice coil.

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ok, does anyone know if 0.005 is the same Le as the adire extremis mids? im trying to compare the mpyre mids to the adire mids.

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They use the exact same motor and therefore it will be identical. The only difference between the two is the cone material used. I will be installing the Mpyre mids in my car on monday hopefully.

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did you order yours factory direct from mpyre? if so what is their number because i cant find anything at all on them, not even a working website. i'd rather not order these from ebay if i dont need to so any info would be appreciated.

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I don't think Mpyre is around any more. Probably the only place to get them is from Ebay. I purchased them from Bob at Creative Sound Solutions who was a dealer. You can see if he still has some. www.creativesound.ca

Oh, I forgot to mention another small difference between the Mpyre and Extremis is the Mpyre is a 4 ohm driver. So parameters will be different due to that as well.

After searching and searching, it seems the only place to get them IS, in fact, eBay. I just bought three sets! (Should've bought four...) I don't ever really want to be out of those, so I'll put 'em on my shelf, till I need 'em!

Thinking about it now, I have some really nice Vifa D-26 silk-dome tweeters that'd match with those just super-de-duper for a kick-*** multimedia system!

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It all reminds me of something that Molière once said to Guy de Maupassant at a café in Vienna: "That's nice. You should write it down."

you should stick all 6 of them in some towers

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Well, 4 of them for sure... I need a pair in reserve! A nice MTM alignment, with the tweeter right at about sitting height? I could listen to WoW sound effects through those, and be pretty darn happy! :) OOH!! A series crossover! Always wanted to try one of those... Perhaps some details to follow, once I have them in hand!

Perhaps a REALLY nice patio speaker system? Since my room IS right there... I have a 440 watt (into 8 ohms, too!) amp... Some FLAC recordings stored up on the home server... Summer IS on the way, and the BBQs flow aplenty at my house in the summer...

Dammit... I gotta stop thinking about it!

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It all reminds me of something that Molière once said to Guy de Maupassant at a café in Vienna: "That's nice. You should write it down."

I happen to have a series Xover design using two Extremis woofers in MTM...

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DYohn] wrote:

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I happen to have a series Xover design using two Extremis woofers in MTM...

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Huh... :)

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It all reminds me of something that Molière once said to Guy de Maupassant at a café in Vienna: "That's nice. You should write it down."

what is an MTM alignment?


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Mid-Tweeter-Mid

Just my guess

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Custom Enclosure Design

aka D'Appolito - the acoustician that described the benefits first...

Some more links with (possibly) very interesting reading...

https://www.diyaudio.com/forums/showthread/t-14774.html

https://en.wikipedia.org/wiki/Joseph_D'Appolito

https://www.htguide.com/forum/showthread.php4?t=14345

The symmetry of the wavefront is the major benefit to this particular design...

aznboi3644 wrote:

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Mid-Tweeter-Mid

Just my guess

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And, yes... Mid-Tweeter-Mid

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It all reminds me of something that Molière once said to Guy de Maupassant at a café in Vienna: "That's nice. You should write it down."

haemphyst wrote:

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After searching and searching, it seems the only place to get them IS, in fact, eBay. I just bought three sets! (Should've bought four...) I don't ever really want to be out of those, so I'll put 'em on my shelf, till I need 'em!

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These might work as another option: https://www.creativesound.ca/details.php?model=SDX7

haemphyst wrote:

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Thinking about it now, I have some really nice Vifa D-26 silk-dome tweeters that'd match with those just super-de-duper for a kick-*** multimedia system!

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Here's the tweeter I'm using with the Mpyre: https://www.acousticdev.com/cms/index.php?option=com_content&view=article&id=56:ceradome-tweeter&catid=38:uncategorized&Itemid=60

You have to love the extension in both directions and the impressive off-axis response.

Steven Kephart wrote:

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haemphyst wrote:

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After searching and searching, it seems the only place to get them IS, in fact, eBay. I just bought three sets! (Should've bought four...) I don't ever really want to be out of those, so I'll put 'em on my shelf, till I need 'em!

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These might work as another option: https://www.creativesound.ca/details.php?model=SDX7

haemphyst wrote:

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Thinking about it now, I have some really nice Vifa D-26 silk-dome tweeters that'd match with those just super-de-duper for a kick-*** multimedia system!

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Here's the tweeter I'm using with the Mpyre: https://www.acousticdev.com/cms/index.php?option=com_content&view=article&id=56:ceradome-tweeter&catid=38:uncategorized&Itemid=60

You have to love the extension in both directions and the impressive off-axis response.

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The SDX-7 is quite good, but optimized for use in a 2-way so it gives up a little low end to achieve better high-end extension.  If you want to cross below 1K try the EX-6.5 from Kevin Haskins at Exodus.  Basically the same spaekr but with better output below 100Hz:  https://www.diycable.com/main/product_info.php?cPath=24_93_150&products_id=538  They both use an improved version of the Extremis/Mpyre motor structure.

I love DW's ceramic dome tweeter.  I have a couple of them staring me in the face right now.  :)

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DYohn] wrote:

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The SDX-7 is quite good, but optimized for use in a 2-way so it gives up a little low end to achieve better high-end extension.  If you want to cross below 1K try the EX-6.5 from Kevin Haskins at Exodus.  Basically the same spaekr but with better output below 100Hz:  https://www.diycable.com/main/product_info.php?cPath=24_93_150&products_id=538  They both use an improved version of the Extremis/Mpyre motor structure.

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Interesting. I didn't think Kevin was going to be selling his midrange outside of his kits. He must have changed his mind.