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Old 8th February 2011, 07:39 PM   #61
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Similar to the Pencil 12.

It can do, although it's a bit sweeping to say it automatically will in all times & conditions. BW limiting will increase power handling & reduce AMD / FMD (doppler). How noticeable or otherwise depends on the box, system, room, material & how hard you're driving it.
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Old 8th February 2011, 08:35 PM   #62
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Quote:
Originally Posted by buzzforb View Post
Is the functional bandwidth of the cabinet different than that of the driver?
Go back & reread post 29.

Let's consider that the energy to excite a resonance is inversly proportional to the 4th power of the frequency.

Let's assume that a typical MDF panel resonantes at 300 Hz. Now consider how much less likely a resonance is to be excited if we can push the panel resonance up to 1000 Hz.

(1/300^4)/(1/1000^4) = 123 times less likely. In a full range speaker one we have energy into the cabinet all the way up, but one can arbitrarily pick a point using the "less likely to get excited" criterion to decide where the functional bandwidth of the cabinet extends.

The chart shows relative likelihood of exciting a resonance at that frequency. Below ~300 Hz, the 4th order supposition breaks down

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Old 8th February 2011, 08:45 PM   #63
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Originally Posted by Scottmoose View Post
Only insofar as there is a common belief that a dense material is automatically 'unresonant.'
Ignoring differences in damping qualities, given 2 panels of the same stiffness, the less dense one (ie the lighter one) is better given the criteria in my last post as resonant frequency is proportional to mass.

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Old 8th February 2011, 08:53 PM   #64
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Thank you Dave and Scott for the lessons. I know its gets repetitive. I am cutting the wood for the enclosures as I type. Hope to report back soon with picks, comments and 10 fingers.

Side note: The driver needs to be recessed about 3/8" leaving only 3/8". Do I need to provide more support for driver?

Last edited by buzzforb; 8th February 2011 at 09:01 PM.
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Old 8th February 2011, 09:07 PM   #65
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Side note: The driver needs to be recessed about 3/8" leaving only 3/8". Do I need to provide more support for driver?
We always add a driver brace, so the lack of infringement on the back-side of the driver is a bonus (we also champher the back side to open it up even more). Mounting the driver on the backside of an aluminum plate/subbaffle 3-4mm thick (and champhered on the front), would take that to extremes.

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Old 8th February 2011, 09:15 PM   #66
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Originally Posted by buzzforb View Post
Thank you Dave and Scott for the lessons. I know its gets repetitive. I am cutting the wood for the enclosures as I type. Hope to report back soon with picks, comments and 10 fingers.

Side note: The driver needs to be recessed about 3/8" leaving only 3/8". Do I need to provide more support for driver?

These do look so yummy when rebated for flush mounting, but the thick resin composite mounting flange does somewhat complicate things.

So yes, since I've been quite happy with the sonic results of a well braced 15mm BB ply cabinet, I usually laminate a small plate of 9mm material on the rear side of cut-outs. Of course one could always machine same in 3mm aluminum and tap for machine screws for the driver mount - but that'd be a bit obsessive, doncha think?



edit: now that's freaky - Dave's reply above posted while typing the above an answering the phone

cheers
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Old 8th February 2011, 09:27 PM   #67
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Ignoring differences in damping qualities, given 2 panels of the same stiffness, the less dense one (ie the lighter one) is better given the criteria in my last post as resonant frequency is proportional to mass.
Agreed, per my previous posts. Give me a panel with a high MOE & decent bracing any day.
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Old 8th February 2011, 09:59 PM   #68
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Originally Posted by buzzforb View Post
Scott,
Do you have the modeled response for the 10.2 like you do for the 12? Also, do you agree with Dave that relieving the FR of its low end repsonsibilities will improve its mid and high frequencies?
Provided you truly relieve the heavy lifting with HP filter and direct amplification of the wide-band driver, you will also appreciate substantially reduced excursion, distortion and power compression, and increased dynamic headroom / max SPLs. This is as true with "full-range" drivers as with more conventional active multi-way systems with W/M/T.


The trick is deciding where to XO, and the number and location(s) of woofer(s). Note that while individual room dimensions/shape will determine the exact transition point, at frequencies often chosen for "subs" (why do I hate that word?) ,the optimal position of LF drivers may not necessary be common with those for the upper portion of bandwidth.
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Old 8th February 2011, 11:14 PM   #69
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"subs" (why do I hate that word?)
Because boom, boom subs designed to appeal to the unsophisticated explosion loving HT crowd have given them a bad name. And because many "subwoofer" drivers are not extended enuff to integrate well.

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Old 8th February 2011, 11:35 PM   #70
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Originally Posted by chrisb View Post
Provided you truly relieve the heavy lifting with HP filter and direct amplification of the wide-band driver, you will also appreciate substantially reduced excursion, distortion and power compression, and increased dynamic headroom / max SPLs. This is as true with "full-range" drivers as with more conventional active multi-way systems with W/M/T.


The trick is deciding where to XO, and the number and location(s) of woofer(s). Note that while individual room dimensions/shape will determine the exact transition point, at frequencies often chosen for "subs" (why do I hate that word?) ,the optimal position of LF drivers may not necessary be common with those for the upper portion of bandwidth.
My eventual woofer addition will be in a FAST type speaker. My hope and current plan is to match the A10.2 with two CA22RNX woofers(I have one pair already). Pass Aleph J monos driving the A10.2 and mono F4's driving woofers. I don't think I could convince the wife about having subs placed strategically though-out the living area unless they could be built into current furniture. I am gearing more towards stereo over HT anyway.
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