Q12 to replace Peerless 830500 in Linkwitz Thor?

[Pultzar 0]

I have two sealed subs 47L enclosures built around the Peerless 830500 driver. This driver is rated at 12.5mm xmax. Details here:

http://www.parts-express.com/pe/showdetl.cfm?Partnumber=297-608

Extensive details about my sub here:

http://www.linkwitzlab.com/thor-intro.htm

Bottom line is that I would like more output as I am bottoming my existing subs. I'm okay with building new boxes but ideally I would like to use the same crossover as it is tailed to work with my main speakers (Linkwitz Orion)

Assuming that the 28mm xmax spec of the Q12 is one way rather than p-p, this driver should give me about 6-7db of headroom. I modeled my 830500 vs the Q12 in WinISD and the results were almost identical within a db or so. Even the efficiency is the same. The other Fi drivers either deviated much more or aren't suitable for sealed enclosures.

Am I right in that this driver could be a drop in replacement without too many other changes? I know that it will sound different since the computer models aren't perfect. But I do expect it to play louder before bottoming.

Since I am in a sealed enclosure crossing over the mains at 50hz, I'm assuming that I want the High QTS option? What does this change the parameters to?

Any other drivers that I should be considering?

Thanks for your help!

[NDMstang65 403]

You would want to select the HQTS option as it is optimized for sealed. It takes out extra material out of the inside of the motor to tame things down to make a bit more of a linear response instead of having a peak due to un-necessary motor force.

50Hz crossover point should be great and you should have no issues using your current enclosure. It should be significantly louder, and you will run out of surround before you bottom the woofer out .

[Pultzar 0]

Is there a comparison between the Q12 and the XCON? Does one apply more in my situation?

Edited February 28, 2012 by Pultzar

[trod2902 26]

Is there a comparison between the Q12 and the XCON? Does one apply more in my situation?

You cant go wrong with either, they are both excellent woofers made in the US and designed for similar applications.

[Pultzar 0]

Thanks for your help everybody.

The Fs is on my existing driver is 18hz while the FiQ/XCON and others is over 30hz. Even though these drives model with the same curves, will the FiQ/XCON have a different frequency response in the lower frequencies or do its other parameters make up for this? I'm not sure how close WinISD predicts actual results.

Edited February 28, 2012 by Pultzar

[ssh 924]

A driver is less efficient playing frequencies below it's Fs (free air resonance); however, this value shifts in an enclosure alignment.

In your case, the value will rise, as the enclosure creates an "air spring." The larger the enclosure volume, the less this value will rise. This could perhaps be a reason as to why larger enclosures are sometimes strived for. As to your other thought, other factors certainly come into play, ie: motor force. That's why generally it's a bad idea to focus on one parameter, and ignore others.

Will the SSA xcon and Fi Q have different frequency responses? Of course.

But will they lack the output your concerned about because of their higher Fs values? Most likely not.

Edited February 29, 2012 by stefanhinote

[Pultzar 0]

Will the SSA xcon and Fi Q have different frequency responses? Of course.

But will they lack the output your concerned about because of their higher Fs values? Most likely not.

Yeah I think they will play pretty loud I'm mostly concerned about the difference in response between a new driver and what I have now (830500) as the crossover is setup for wonderful integration. However if necessary I can measure the before/after and adjust the crossover or EQ to get a close match.

[ssh 924]

I can't say I know much about your crossover network, and how the new driver will blend in. You'll have to post your results after installation.

[Pultzar 0]

I can't say I know much about your crossover network, and how the new driver will blend in. You'll have to post your results after installation.

Fortunately I have two subs so I can change one and then compare them against each other. Or it might just sound awesome. I find that the room itself makes more difference then most things.