Servodrive style install

[ciaonzo 5,000+ posts]

Doesn't matter if the trunk has a resonant frequency. Of course it does. But if the trunk has a higher Vas than that of the drivers then the Fs of the drivers will dominate and decide your "tuning".

The system in the second picture is not from Coustic. It's from Servodrive. It's called that because of the servo style motor used, not because of a closed loop feedback correction system being employed. Those were designed to be used in very high output horns for outdoor venues and such. The car audio version that we would be familiar with is the Phoenix Gold Cyclone, the difference being the lack of linkage, belts, and cones. Instead the vane was directly mounted onto the shaft of the motor.

This got way off track guys.

 

[grimreper912003 5,000+ posts]

I just answered your question fella, or possibly lady (you do get your feelings hurt quite easy). I answered you that it was sealed and would be large and tuned low. I simply forgot the cute smiley faces and things that would make you feel comfortable with the post I suppose.
Actually no I did use a smiley so I must have just not used enough.....

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You didnt answer me. You answered my question with another question then repeated the statment I questioned.

This is an answer to my question:

Doesn't matter if the trunk has a resonant frequency. Of course it does. But if the trunk has a higher Vas than that of the drivers then the Fs of the drivers will dominate and decide your "tuning".
The system in the second picture is not from Coustic. It's from Servodrive. It's called that because of the servo style motor used, not because of a closed loop feedback correction system being employed. Those were designed to be used in very high output horns for outdoor venues and such. The car audio version that we would be familiar with is the Phoenix Gold Cyclone, the difference being the lack of linkage, belts, and cones. Instead the vane was directly mounted onto the shaft of the motor.

This got way off track guys.

My feelings were not hurt, but its silly to answer my querstion like I'm a 5 year old. I'll admit Im not a huge SQ guy but I am willing to learn. Its not like I told you the free air setup wasnt tunned. I asked to know how it works.

 

[JL Audio 5,000+ posts]

o. l. t. = old lady tits?

 

[o. l. t. 10+ year member]

Old lady taco?

 

[audioholic 5,000+ posts]

Doesn't matter if the trunk has a resonant frequency. Of course it does. But if the trunk has a higher Vas than that of the drivers then the Fs of the drivers will dominate and decide your "tuning".
The system in the second picture is not from Coustic. It's from Servodrive. It's called that because of the servo style motor used, not because of a closed loop feedback correction system being employed. Those were designed to be used in very high output horns for outdoor venues and such. The car audio version that we would be familiar with is the Phoenix Gold Cyclone, the difference being the lack of linkage, belts, and cones. Instead the vane was directly mounted onto the shaft of the motor.

This got way off track guys.

A servo motor employs a feedback system. I believe the difference between that style, and one like a Velodyne, is the feedback is directly applied to the electric motor.
http://en.wikipedia.org/wiki/Servomechanism

You are, of course, exactly correct about the nature of an IB system being directly linked to the speaker's Fs given a specific airspace above Vas in the trunk. Good call there.

 

[Ctesibius 10+ year member]

Take another look at the Coustic's in the photo.
Theres no magnets, the cones are moved by an electromagnetic motor in the port itself.

The Coustic Bass Pumps were standard transducers mounted on to a manifold, just the same as this guy is doing.

The 2nd pic is of a mechanical servodrive system, but not the Coustics.

 

[ciaonzo 5,000+ posts]

A servo motor employs a feedback system. I believe the difference between that style, and one like a Velodyne, is the feedback is directly applied to the electric motor.
http://en.wikipedia.org/wiki/Servomechanism

You are, of course, exactly correct about the nature of an IB system being directly linked to the speaker's Fs given a specific airspace above Vas in the trunk. Good call there.

Yeah, I think the difference between a closed loop feeback correction circuit for driver and one for a DC servo motor is one of simplicity. I think the circuit for the servo motor has a lower sampling rate and involves photoemitters with an anolog strip with marks on it to know where the rotation of the shaft is. So it needs not only a circuit to recognize that, but also a circuit to interface with the audio signal because the motor is DC and needs direction change information. An engineer could probably articulate that much better than I'm able to. I guess I'm trying to say it's a bit more crude while at the same time, a bit more involved. The circuit for the Velodyne is far simpler but more precise I think. I'll have to read up on it now. *Shrugs*

EDIT- I guess I should have read that Wiki link before responding due to some of the distinctions being made between the types but I'll let it stand. Chalk it all up to learning and progressive improvement. //content.invisioncic.com/y282845/emoticons/smile.gif.1ebc41e1811405b213edfc4622c41e27.gif

 

[Ctesibius 10+ year member]

Do you suggest the trunk simply have no frequency at all? Of course it is tuned, this is a free air setup so it is the enclosure. //content.invisioncic.com/y282845/emoticons/smile.gif.1ebc41e1811405b213edfc4622c41e27.gif

Good luck with "tuning" your IB setup

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[Ctesibius 10+ year member]

A servo motor employs a feedback system. I believe the difference between that style, and one like a Velodyne, is the feedback is directly applied to the electric motor.
http://en.wikipedia.org/wiki/Servomechanism

I think the section you are looking for in that article would be the section labeled "RC Servo", where there is no automatic controlled feedback system but rather a manually operated control system (the remote....or in our case, the signal input from the amplifier).

 

[o. l. t. 10+ year member]

Good luck with "tuning" your IB setup
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All it takes is a few bodies.

 

[ciaonzo 5,000+ posts]

All it takes is a few bodies.

At least you have a sense of humor and I can appreciate that.

 

[ciaonzo 5,000+ posts]

I think the section you are looking for in that article would be the section labeled "RC Servo", where there is no automatic controlled feedback system but rather a manually operated control system (the remote....or in our case, the signal input from the amplifier).

Maybe a bipolar stepper motor?

http://en.wikipedia.org/wiki/Stepper_motor

 

[audioholic 5,000+ posts]

Stepper motors, and servo controlled motors, while creating similar results, are different animals. Im no electrical engineer, but from my understanding this is the case anyway.