Tom Mobley Posted November 1, 2005 Share Posted November 1, 2005 For use in a dual driver Cornwall type design? Is one of the Eminence drivers similar in characteristics but 8 ohm instead of 4? Maybe there's a JBL out there? In fact, I've seen a couple different takes on the T/S numbers for the K-33. Is there substantial agreement on which numbers are best? Quote Link to comment Share on other sites More sharing options...
DrWho Posted November 1, 2005 Share Posted November 1, 2005 All the T/S parameters yield very similar results (within +- 1dB) so nothing to worry about. Real life variations will be far greater. I am a particular fan of the Eminence Magnum 15" LF. It has 3dB less sensitivity but will give you an F3 of 31Hz versus 38Hz and have the same max acoustical output (right around 120dB). The Magnum should also behave slightly better above 500Hz with about the same dispersion pattern as the K-33. (These numbers are derived using an 8 cubic foot volume, which yields a flatter response than the stock cornwall). I've never actually heard the magnum, but it certainly models up very very nicely. So I would expect real life results to be favorable, but alas there is nothing better than actually hearing one. If space is a concern, the magnum can fit in a smaller cabinet than the K-33 and still get the same frequency response. In fact, the cornwall has a cabinet volume of 6.2 cubic feet tuned to 47Hz. The magnum achieves the exact same slope in a 4 cubic foot box tuned to 45Hz. When going with a dual driver system....that means 8 cubic feet for the magnum versus 12.4 for the K-33. This means you could go with 3 magnums in the same space as 2 K-33's! Quote Link to comment Share on other sites More sharing options...
Tom Mobley Posted November 1, 2005 Author Share Posted November 1, 2005 from the eminence site: {EDIT} I reformatted this three times, but the BBS software keeps moving the right column up or down one line. Dang. Nominal Basket Diameter Impedance Power Rating Resonance Usable Frequency Range Sensitivity Magnet Weight Gap Height Voice Coil Diameter Mounting Information Recommended Enclosure Volume Volume Displaced by Driver Overall Diameter Baffle Hole Diameter Front Sealing Gasket Rear Sealing Gasket Mounting Holes Diameter Mounting Holes B.C.D. Depth Shipping Weight Thiele-Small Parameters Resonant Frequency (fs) Impedance (Re) Coil Inductance (Le) Electromagnetic Q (Qes) Mechanical Q (Qms) Total Q (Qts) Compliance Equivalent Volume (Vas) Peak Diaphragm Displacement Volume (Vd) Mechanical Compliance of Suspension (Cms) BL Product (BL) Diaphragm Mass inc. Airload (Mms) Equiv. Resistance of Mechanical Suspension Loss (Rms) Efficiency Bandwidth Product (EBP) Voice Coil Overhang (Xmax) Surface Area of Cone (Sd) Impedance at Resonance (Zmax) Maximum Mechanical Limit (Xmech) X10 15", 381mm 8 ohms 700Wrms 37Hz 28Hz - 1.4kHz click here for guide 109oz., 3.1 kg. 0.375", 9.5mm 4", 101.6mm 84 - 168 liters 3 - 6 cu. ft. 4.5 liters, 0.159 cu. ft. 15.21", 386.4mm 14.0", 355.5mm fitted as standard fitted as standard 0.275", 7mm 14.56", 369.9mm 6.42", 163mm 26lbs., 11.8kg. 37Hz 4.95 ohms 1.21mH 0.48 9.42 0.45 163 liters 5.76 cu. ft. 677cc 0.1579mm/N 16.88 T-M 119 grams 2.919N*sec/M 76.8 7.9mm 856cm2 122 ohms 30.94mm 11.3mm Quote Link to comment Share on other sites More sharing options...
DrWho Posted November 1, 2005 Share Posted November 1, 2005 That's the one! If you have WinISD you will notice that it is already in the list of included drivers so you won't have to manually enter them yourself. Here's a link to the PDF: http://www.partsexpress.com/pdf/290-580.pdf Quote Link to comment Share on other sites More sharing options...
jwc Posted November 1, 2005 Share Posted November 1, 2005 If you are going to run the WinISD program, try out some of the Eminence Delta drivers. They will also work with the project you are seeking. The Delta drivers are not as high dollar as the magnums and have the same type curve as a K33 in a cornwall cabinet. The Magnum is a much better driver than the K33 I would guess. It depends on what your project is. If you have flexibility with cabinet volume and porting, I would move away from the whole "K33" concept. I used the K33's in my dual setup because I wanted it to have bass just like a Cornwall. Quote Link to comment Share on other sites More sharing options...
Al Klappenberger Posted November 1, 2005 Share Posted November 1, 2005 Tom, Here is a possibility. It's the woofer driver Dman has chosen for his Jubilee clone woofer horn. I have measured one that he sent me and found that it is actually 10.2 Ohms in sereis with 1.6 mHy at 600 Hz. If you put two in parallel it would represent 5.1 ohms in sereis with .8 mHy. That is close enough to 6 Ohms in sereis with 1.0 mHy to work ok with my ES600 extreme-slope network. I'll let the rest of the problems invoilved with developing a ported box for two of them up to you! Al K. Quote Link to comment Share on other sites More sharing options...
jwc Posted November 1, 2005 Share Posted November 1, 2005 Al, You confused me there. I though optimal woofers for your ESN's needed a VC inductance around 1 mH and 6 ohms. Is this right? Of course I wondered how the K33 with an impedance of 3.39 ohms fit in there. Maybe it isn't as important to stay exactly on spec. So what I hear you saying is that having two woofers in parallel resulting in 5.1 ohm is ok as well as an inductance of 0.8 with your ESNs? Maybe I just restated what you just posted. Now that I look at it; hell it is the same. I guess I was wanting to know how far off spec is allowed for woofer substitutions with your designs. Also, I always wondered what you do with the VC inductance value when you wire in parallel vs series. What is the Rule there. Looks like the rule is the same as what you do for impedance. 1/2 for parrallel and 2x for series. jc Quote Link to comment Share on other sites More sharing options...
DrWho Posted November 1, 2005 Share Posted November 1, 2005 Them's some nasty peaks and dips with that CB-15 in the 100-500Hz region. Do you really think it would be a step up from the K-33? Maybe perhaps a lateral movement to obtain an 8ohm driver (but that seems kinds silly to me). What's the incentive to finding a pair of 8 ohm drivers? Wouldn't it be cheaper/better to just rework the crossover? Quote Link to comment Share on other sites More sharing options...
Al Klappenberger Posted November 1, 2005 Share Posted November 1, 2005 JC, The K33 is NOT 3.3 Ohms. It's roughly 6 Ohms in sereis with 1 mHy inductace. The "ES" networks will work well as long as the woofer driver is roughly equal to the K33. As a round guess, 5 to 7 Ohms in sereis with 0.5 to 1.5 mHy should be ok. I have tested them into quite a few complex loads andt is not a critical thing. The more you depart from the K33 the rougher the woofer filter passband gets. It just becomes a question of how rough you can accept. Becides, Tom is considering two drivers connected in parallel. That cuts everything in half. AL K. Quote Link to comment Share on other sites More sharing options...
jwc Posted November 1, 2005 Share Posted November 1, 2005 Here are most of your Eminence options with 8 ohm drivers. Quote Link to comment Share on other sites More sharing options...
jwc Posted November 1, 2005 Share Posted November 1, 2005 Here is the jbl 2226 (green) and the E. Magnum LF (red) and K33 (white) Quote Link to comment Share on other sites More sharing options...
DrWho Posted November 1, 2005 Share Posted November 1, 2005 Dude, you gotta optimize the cabinets and tunings seperately for each of those drivers. Doing that dip before a round peak and then dropping off sounds horrible (poor transient response). I haven't modelled the other drivers, but I know you can get far far better slopes with the magnum (in fact, you can match the cornwall identically with the smaller cabinet or you can go with a flat fast transient response and go about 10Hz lower). Btw, I actually own a JBL 2226 and wouldn't recommend it over the K-33. It's low distortion and all, but lacks a certain oompf to the sound. I would describe it as sounding like a PA speaker [] (I've heard it used in a few configurations and I'm definetly not a fan for home use). Quote Link to comment Share on other sites More sharing options...
jwc Posted November 1, 2005 Share Posted November 1, 2005 Dude, you gotta optimize the cabinets and tunings seperately for each of those drivers. Doing that dip before a round peak and then dropping off sounds horrible (poor transient response). I haven't modelled the other drivers, but I know you can get far far better slopes with the magnum (in fact, you can match the cornwall identically with the smaller cabinet or you can go with a flat fast transient response and go about 10Hz lower). Btw, I actually own a JBL 2226 and wouldn't recommend it over the K-33. It's low distortion and all, but lacks a certain oompf to the sound. I would describe it as sounding like a PA speaker [] (I've heard it used in a few configurations and I'm definetly not a fan for home use). Doc. Settle down. I responded to his initial post which was for alternative drivers in a Cornwall type cabinet. Yes. they look like crap. Personally, I wouldn't go for any other driver in that cabinet but the K33. If i were to invest in a different driver, I would use different cabinets and ports. jc Quote Link to comment Share on other sites More sharing options...
D-MAN Posted November 1, 2005 Share Posted November 1, 2005 I have arrived at that conclusion, too. The K33E is optimized for a horn driver, and is best in a very particular horn, and it has some drawbacks as a reflex driver because of it. Remember that PWK used what he had on hand, and evidently got a kick out of getting the best sound quality he could out of relatively cheap components. That was business. First, its cone is a little light for direct radiating use. It's magnet is also a little undersized. It works, but HEY, there are many other drivers that are specifically designed to perform in areas that the K33E is not. I would take the very sage advice mentioned above, and go for the gusto, and select a design and a driver specifically matched for it. DM Quote Link to comment Share on other sites More sharing options...
Deang Posted November 1, 2005 Share Posted November 1, 2005 When you horn load a driver, its impedance goes up. In the case of the K-33 -- it almost doubles. At any rate, it's spec'd out as a 4 ohm driver, and should probably be treated as such in a straight up design. Quote Link to comment Share on other sites More sharing options...
D-MAN Posted November 1, 2005 Share Posted November 1, 2005 2- 8's wired in parallel would be just fine, and you could probably use a Klipsch-style crossover like Al K. said above. The Magnum LFA is a fine driver, but 4 of them will be SPENDY. Scratch that - 4 of anything is spendy, come to think of it! DM Quote Link to comment Share on other sites More sharing options...
D-MAN Posted November 1, 2005 Share Posted November 1, 2005 Them's some nasty peaks and dips with that CB-15 in the 100-500Hz region. Do you really think it would be a step up from the K-33? Maybe perhaps a lateral movement to obtain an 8ohm driver (but that seems kinds silly to me). What's the incentive to finding a pair of 8 ohm drivers? Wouldn't it be cheaper/better to just rework the crossover? You should not believe what the manufacturer publishes (or at least stay skeptical)! Especially frequency response curves (or sensitivity ratings either). It also has nothing to do with it being tested in a horn. Al K's hands-on testing of the driver in question had a different outcome. DM Quote Link to comment Share on other sites More sharing options...
DrWho Posted November 1, 2005 Share Posted November 1, 2005 eeek, I wasn't upset at all....sorry if I came off that way. D-Man, I would be curious to find out what you specifically find lacking in the K-33 for normal direct radiating duty. Michael Hurd and I have spent many hours modelling all sorts of drivers to find something that definetly exceeds the K-33 in performance for a normal ported application and we are yet to find any distinct winners. At least I don't think we're overlooking anything.... Quote Link to comment Share on other sites More sharing options...
D-MAN Posted November 1, 2005 Share Posted November 1, 2005 Bear in mind that I selected the driver for a horn driver application only. I believe in selecting the right tool for the job. I think that it is best as a purpose-built horn driver rather than forced to do double-duty as a direct/reflex driver. It has some attributes that are quite specific to the small-slot horn loading application it is best used for. The cone is too light (good for horn driver, bad for direct radiator), its Vas is too large compared to most "modern" drivers where the reduction of Vas is one factor that has improved over the years, in keeping with the desire to reduce cabinet sizes. It also has a somewhat rapid upper freq. mass rolloff compared to other drivers, good for the Khorn which crosses over at 400Hz, but not so good for a direct radiating application. A larger magnet and a higher wattage handling ability would also be nice, IMO. This would basically mean an 8 Ohm vc right of the bat. When used outside of a horn, it's reduced efficiency could theoretically promote over-driving the unit's somewhat limiting (by todays standards)150w rating. Alot of this is opinion, although some of this is sound thinking. DM Quote Link to comment Share on other sites More sharing options...
DrWho Posted November 1, 2005 Share Posted November 1, 2005 So translated you don't like the size of the cornwall cabinet and you want to get louder than 120dB max (which of course will reduce power compression) [] Quote Link to comment Share on other sites More sharing options...
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