# Looking for a 10" woofer to match the usher 8945P



## bdubs767 (Apr 4, 2006)

http://www.partsexpress.com/pe/showdetl.cfm?&Partnumber=296-602

I am in the process of designing a speaker system, well actually going off of these designs http://www.geocities.com/woove99/Spkrbldg/ 
Im looking to add a 10" woofer to the system actively and was wondering what would be a good match to match the timber ect.?


I know usher offers a 10" how about that? I would love to use the dayton but I dont think the metal cone woudl match well.

I would also consider 8s too....I would love to add two of those new dayton HF 8" subs to the bottom on each. Just worried about the metal cone matching with the paper.


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## thadman (Mar 1, 2006)

What crossover point and slope do you require/desire?

The Peerless XLS and ATC SB75 are both excellent examples of low-distortion paper-cone subwoofer drivers. I see no problem in using either up to 150hz (the ATC could probably be taken up a few octaves higher if excursion was kept to a minimum, keeping intermodulation and doppler distortion in check).

Also, take notice that standing waves can only form in the medium if they do not exceed 1/2 wavelength of the longest dimension (ie I wouldn't be worried about the membrane breaking up). Interactions between the membrane and the surround for example would be a much better use of your attention. These interactions can be viewed by observing the drivers Impedance plot. As long as you don't have any serious impedance perturbations you should be good to go.


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## bdubs767 (Apr 4, 2006)

thadman said:


> What crossover point and slope do you require/desire?
> 
> The Peerless XLS and ATC SB75 are both excellent examples of low-distortion paper-cone subwoofer drivers. I see no problem in using either up to 150hz (the ATC could probably be taken up a few octaves higher if excursion was kept to a minimum, keeping intermodulation and doppler distortion in check).
> 
> .


I would be shooting for around 80hz to 100hz, I wont be desinging the xover though if I add the 10" to the passive xover, I would be sending off the baffles once made, to have them measured ect on leap to design the xover, then fine tweak from there.
I most likely will just actively cross them over, but just add the 10" to the bottom of the enclosure of the HDS and Usher. 

I didnt even think of the XLS, perhaps that with the PR at the bottom of each tower.....



thadman said:


> Also, take notice that standing waves can only form in the medium if they do not exceed 1/2 wavelength of the longest dimension (ie I wouldn't be worried about the membrane breaking up). Interactions between the membrane and the surround for example would be a much better use of your attention. These interactions can be viewed by observing the drivers Impedance plot. As long as you don't have any serious impedance perturbations you should be good to go


huh?


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## thadman (Mar 1, 2006)

I really wouldn't worry about conflicting acoustic personalities at 80-100hz. Almost all drivers will exhibit linear response at these frequencies.

If significant output or displacement is not required, I'd wholeheartedly recommend either the Aurasound NS10-513-4A or NS12-513-4A (the low-xmax versions). They require large boxes, but are currently the lowest distortion woofers that have been tested over on htguide (very linear and complimentary low distortion out to 600hz). If significant output or displacement is required, their bigger brothers would be more appropriate.

Linkwitz has had great success with the Peerless XLS line of woofers. He uses them in a dipole alignment in the Orion up to ~150hz and also the Thor in a mono alignment which is used as an adjunct to the Orion below 50hz.

I don't think you could go wrong either way.


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## bdubs767 (Apr 4, 2006)

w/ the aura wouldnt I have to worry about the metal cones timbre matching w/ the timbre from the paper cone?


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## thadman (Mar 1, 2006)

I wouldn't be too concerned about it. The factors that differentiate the membranes are their linear performance (ie breakup) and interaction between the surround, joints, etc (ie any impedance perturbations).

They will both be almost perfect pistons in the bandwidth you described, although their breakup behavior may manifest itself lower in frequency as harmonic distortion. If you wanted to differentiate them, I'd look towards their harmonic distortion performance and impedance plots.

Just for reference, Linkwitz crossed the magnesium W22EX to the paper XLS around 150hz...if timbre matching around this bandwidth was an issue he probably wouldn't have chosen the drivers he did.

Also, the Aurasound has a rigid cone, and thus very high breakup and correspondingly can be used up throughout the lower midrange without harmonic distortion woes (100hz is a walk in the park).

If you are anal, you could try the Peerless XLS although I cannot speak for its performance.


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## backwoods (Feb 22, 2006)

Xls would fit the bill, and with the usher, you would be fine playing above 100hz if needed.

Now, the xls with a mag cone, not as nice of a match above 100hz. When male vocal fundementals start coming through, you notice the change between the drivers. 

I believe the orions are actually crossed around 110 and that's using steep LR filters. Because of the change in timbre is most noticable in vocals, it creates a vertical imaging issue if you are within ~10' of the drivers. 

But, I would not hesitate to use XLS with Ushers and feel safe to cross even higher then the 80 mark you mentioned.


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## thadman (Mar 1, 2006)

Linkwitz Lab said:


> Crossovers at 120 Hz and 1440 Hz, both LR4 (24 dB/oct)


We were both off slightly, wish I had another excuse, but I can only attribute the misinformation to laziness 

BTW I believe the main decision to cross low was to avoid the fundamental resonance of the H-frame


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## thehatedguy (May 4, 2007)

Would Usher's 10 work? I'm not too much into the lower efficiency stuff, just throwing out another idea.


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## backwoods (Feb 22, 2006)

thadman said:


> We were both off slightly, wish I had another excuse, but I can only attribute the misinformation to laziness
> 
> BTW I believe the main decision to cross low was to avoid the fundamental resonance of the H-frame


I shouldn't have an excuse. Last year I built a pair of Orions. I was very impressed but there were a couple issues I had with them that left room for improvement. 

Back on topic...

I've never used the Usher 10's, so if you go for it, let us know how they sound!

I have a pair of JBL 15's that would do great for that situation, but they are kinda ugly for in a house where they might be seen. High efficiency/low xmx variety...


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