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How would you upgrade stock Cornwall Is with a $2000 budget?


synthfreek

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I can handle just opening up that hole a bit to accommodate the mid horn but that's about as far as I'd feel comfortable. The obvious advantage of hot-rodding my current speakers is the fact that I'd be able to just throw a few hundred bucks into the project whenever I could instead of plunking down one lump sum.

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Nah, I like to set the wood horns on top. This puts the mids up where I want them anyway. Install new binding posts on the back of the cabinet to connect to your mids (or use the new posts for your inputs and use the old input posts to output your mid connection from the networks).

Dean, I was just mentioning he wouldn't want to try to run a network with a 400hz crossover with the k600 horns. He would need to make the crossover and horn change at the same time.

My current/temporary bedroom setup (with a loving and understanding wife):

1968 Cornwalls with Fastracs on top and k55m mid drivers.

ALK Cornscala-wall networks (caps have been replaced with Mundorf EVO aluminum oil)

Crites CT-125 tweeters.

These upgrades could be taken one at a time and would be way under budget but still really nice results.

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if you love your Cornwall's that much and want to keep them, I would say that a lot of Gothover's upgrades are a winner.

However consideration would be to sell them and get a pair of a la scalas and a sub. That combo work for me for years.

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Dave shoehorned the Eliptrac and B&C DE85 into a stock cornwall I owned.. had 3/4-1" of clearance.

With the eliptrac you wil need to add a brace to inside... will help stiffed the cab... super easy 3 pieces of wood.

Mid horns to be considered woud be: the Faital 1.4" (Most 1.4" drivers are more expensive then 2") (eliptical design, better imaging and sweet spot)

the JBL M2380 clone... (2" driver, fits inside a cornwall, CD horn great sound all over but less imaging)

the Eliptrac 400. (2" driver, Most dense horn... extremly inert, the proven choice for many)

Dave's new HF horn will allow a simple upgrade without any can mods to make it happen... a real possitive!

The Eminence Kappa 15C 4ohm massive magnet... monster bass...

Edited by justinsweber
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My Radian coaxials don't have any xmax either, but I can unload 200wpc into them and it's oh so clean. But then, I'm only running them down 60Hz. :)

Don't know squat about low pass systems, I hate them.

So, he's getting good bass with no xmax, how does that work?

Edited by DeanG
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My Radian coaxials don't have any xmax either, but I can unload 200wpc into them and it's oh so clean. But then, I'm only running them down 60Hz. :)

Don't know squat about low pass systems, I hate them.

So, he's getting good bass with no xmax, how does that work?

I’ll take a shot and look for our various engineers’ understanding to confirm or clarify, but tend to agree with Dave, unless of course he is trying to drive out the neighbors down the street with bass output, the xmax may not be a problem in the cornwall speakers (I don't think the K-33 has high xmax either).

I believe that AES characterizes Xmax as the distance the voice coil can travel until a 10% deviation in the linearity of low frequency response occurs. Essentially, the woofer output becomes non-linear when the voice coil begins to leave the magnetic gap and distortions increase (I do realize that woofer suspensions can create some non-linearity in output).

When the Xmax of the woofer is not proper for the speaker design or have the appropriate use of a subsonic filter (acknowledging that Xmax is only one parameter of many for which all can have influence a speaker’s performance and sound), in some cabinets and under certain conditions, the cone “unloads,” and the cone excursion increases greatly.

This effect can be thought of similar to how I tried to explain “horn loading” and “unloading” and the impact on diaphragm excursion in Dave’s Eliptrac 240 thread when running a signal through the compression driver / horn combination below the cutoff frequency. The excessive excursion also can happen in ported speakers below the port tuning frequency. As you are aware, “horn loading” the K-33 woofer in a Klipschorn will greatly reduce excursion of the cone for a given output and reduce distortions over direct radiator applications.

I guess that when these conditions are encountered the speaker is easily driven, and if too much power applied at those frequencies, the cone can travel too much and the voice coil could strike the back of the magnet assembly, damaging the voice coil.

This is where good speaker design is important (just like cross-over network design). When Xmax is entered into modeling programs it can show the designer the power limit at various frequencies. If the excursions of the woofer are too great the power handling is substantially reduced. For example, a woofer may model fine to 35Hz at 200 watts power, but could drop to handling only 30 watts at 25Hz (which would drive the voice coil far out of the gap).

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Guest David H

That's what I get for reading the specs off of the Parts Express website.

Eminence Kappa-15C 15" Driver 4 Ohm
Product Specifications
  • Nominal Diameter15"
  • Power Handling (RMS)450 Watts
  • Power Handling (max)900 Watts
  • Impedance4 ohms
  • Frequency Response52 to 2,300 Hz
  • Sensitivity100.5 dB 1W/1m
  • Voice Coil Diameter3"
  • Magnet Weight80 oz.
Thiele-Small Parameters
  • Resonant Frequency (Fs)33 Hz
  • DC Resistance (Re)5.22 ohms
  • Voice Coil Inductance (Le)1.05 mH
  • Mechanical Q (Qms)8.9
  • Electromagnetic Q (Qes)0.33
  • Total Q (Qts)0.32
  • Compliance Equivalent Volume (Vas)11.35 ft.³
  • Mechanical Compliance of Suspension (Cms)0.31 mm/N
  • BL Product (BL)15.7 Tm
  • Diaphragm Mass Inc. Airload (Mms)76g
  • Maximum Linear Excursion (Xmax)4 mm
  • Surface Area of Cone (Sd)856.3 cm²
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"Ready to do that battery biased network? We can call it "The DJK"."

Yes, I just got a pair of autoformers from BEC, and some nice inexpensive PIO caps to try it out with. Trying to decide type A, AA, or other. Have enough caps for two pair of type A.

BMS details sent 6PM CST.

Edited by djk
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