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Discussion Starter · #1 ·
Hi Kevin

For the Tempest X2, the 'Volume Occupied by Driver' spec is given as .18 cubic feet. Is this mounted with the driver flange on the outside of the front baffle?
Like this?
(Sorry to the the owner of this leaky looking diagram; I just googled for reference).


If so in what thickness timber? I've always wondered just how accurate you need to be with how you measure driver volume as most reccomend the plastic bag overall displacement technique but this misses out all the airspace in and around the basket. Is the spec you have stated above literally accurate; i.e. to include this 'inside basket' airspace?

My other question was for design purposes - what is the volume occupied by the PR15 passive please? I assume you might have it on hand. I guess this would also be given mounted in a similar way to the driver and assumed flange outside the baffle as above?

Thank you very much for your time Kevin!

Paul
 

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Hi Kevin

For the Tempest X2, the 'Volume Occupied by Driver' spec is given as .18 cubic feet. Is this mounted with the driver flange on the outside of the front baffle?
Like this?
(Sorry to the the owner of this leaky looking diagram; I just googled for reference).


If so in what thickness timber? I've always wondered just how accurate you need to be with how you measure driver volume as most reccomend the plastic bag overall displacement technique but this misses out all the airspace in and around the basket. Is the spec you have stated above literally accurate; i.e. to include this 'inside basket' airspace?

My other question was for design purposes - what is the volume occupied by the PR15 passive please? I assume you might have it on hand. I guess this would also be given mounted in a similar way to the driver and assumed flange outside the baffle as above?

Thank you very much for your time Kevin!

Paul
Trust me, unless you are designing some tricky small volume bandpass enclosure it just doesn't matter. Just change the box model you are playing with by +/- 0.2 cubic feet and you likely see very little difference. That type of volume difference just does not have audible consequences in our normal sealed or ported designs.

Kevin Haskins
Exodus Audio
 

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Discussion Starter · #3 ·
Great thanks Kevin; I value your input.

Any ideas on what driver occupied volume to use for your 15 and 18 passive radiators?

Cheers
 

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Paul I suggest you some modeling in winisd. Play around with the volume and see just how much a difference it makes. You will probably be surprised about the tolerance you have in box volume. I never flush mount bass drivers. I prefer to have the lip out. except on a tweeter of course.
 

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Discussion Starter · #5 · (Edited)
Thanks lsiberian.

I'm still keen to get hold of the 'Volume Occupied by Driver' of the passive radiators to mock up some design models for the enclosure in Sketchup.

Does anyone have any specs/measurements from previous builds?
 

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Thanks lsiberian.

I'm still keen to get hold of the 'Volume Occupied by Driver' of the passive radiators to mock up some design models for the enclosure in Sketchup.

Does anyone have any specs/measurements from previous builds?
You can ignore any volume they take up. It is almost nil and even if you calculated their exact overall volume it wouldn't matter. It is well below the threshold for any tolerance in these designs.

Kevin Haskins
Exodus Audio
 

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Discussion Starter · #7 ·
Thanks again Kevin.

I guess I was trying to be as exact as I could as everywhere I read I see about how spot on ported and passsive radiator systems have to be in design (compared with sealed). But it seems I have been going a bit over the top! :gulp: I didnt quite know where that line was.

Cheers!!
 

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Thanks again Kevin.

I guess I was trying to be as exact as I could as everywhere I read I see about how spot on ported and passsive radiator systems have to be in design (compared with sealed). But it seems I have been going a bit over the top! :gulp: I didnt quite know where that line was.

Cheers!!
Most people don't. It is true, is really small boxes where the proportion of overall volume/driver volume ratio is small you might have to watch it. In all the designs for our drivers, that ratio is relatively large and the impact of 0.2 cubic feet is extremely minor. That isn't the case in all designs but it is when you are talking about a 7-8 cubic foot box.

Kevin Haskins
Exodus Audio
 
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