Paradigm SUB 15, Ken Kreisel 5000 Mark3 subwoofer advice advice needed..

Dependant on the design, 1/3 - 1/2 of the roll surround counts towards driver radiating area. A properly designed larger roll surround wont have any issues solved by a smaller surround that will in anyway affect the function of the driver.

If you understand how a subwoofer driver works, then the statement is pretty generic and meaningless anyway, but thats not important here really anyway. My point was that a marketing statement was made that is misleading, and I really dont like misleading statement and feel compelled to correct them. I make no negative statement about Ken himself or the product, nor would I ever. I actually spent a lot of time learning a lot from Ken when I got into designing and building my own subwoofers.

[/quote]If you understand how a subwoofer driver works, then the statement is pretty generic and meaningless anyway, but thats not important here really anyway. My point was that a marketing statement was made that is misleading, and I really dont like misleading statement and feel compelled to correct them. I make no negative statement about Ken himself or the product, nor would I ever. I actually spent a lot of time learning a lot from Ken when I got into designing and building my own subwoofers.

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All i took from the statement was if you want to compare this sub you need to be looking at 18" subs on a performance level not necessarily better but on a par. It's doesn't have to do this to every 18" sub ever made it in fact only has to be comparable to one 18" sub to be a genuine statement.

I don't see how this is any different than saying this is an M+S sandwich..... this is a KK sub.

Why is it such an issue to you ?

 

 

The roll surround isn't travelling at the same speed as the actual driver area, so is more or less irrelevant to the amount of air that driver can shift. It's easy to say that the inside 1/2 is moving, so adds to the area, but because of e speed it is moving, it is adding very little to the overall output, if anything. That's probably something dreamed up by the manufacturers of subs with large roll surrounds. A larger roll surround adds to the overall weight of the driver, which in turn affects its efficiency, and effective speed. If you'd like to check out those facts, feel free to double check them with Ken Kreisel.

Once again Dan, feel free to comment when you have heard the DXD12012. After all, you yourself said that you learned much of what you know from Ken.

How come you're always comparing subs by surface area then? You can't twist words to suit your argument Dan. Well, you can, but those that know better can see through it.

So it IS possible? Do make up your mind Dan. On one hand you're saying its impossible, and now you're saying it is. I'm sure Ken has taken into account the legal side of what he has said. I mean, he isn't stupid, is he? He invented the powered subwoofer, after all....

 

But you also said this:

You yourself has said that amplification is important for a subwoofer's performance. Ken's subs use a dual amplifier. Some other subs use dual amplifiers as well, but Ken's use those dual amps in a push/pull configuration, which I'm not sure any other manufacturer does. One manufacturer rubbished push/pull amplification, but then, it is a manufacturer of budget subwoofers Could this configuration not help Ken's subs achieve their goal? Do you have first hand experience of dual push/pull amplification in subs Dan?

Once again Dan, you have no first hand experience of Ken's new subs, which are quite a jump from his previous models and those now adopted by MK Sound.

well then be a sport and offer to lend him a new sub

I would, but he's in Spain.

If you understand how a subwoofer driver works, then the statement is pretty generic and meaningless anyway, but thats not important here really anyway. My point was that a marketing statement was made that is misleading, and I really dont like misleading statement and feel compelled to correct them. I make no negative statement about Ken himself or the product, nor would I ever. I actually spent a lot of time learning a lot from Ken when I got into designing and building my own subwoofers.

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All i took from the statement was if you want to compare this sub you need to be looking at 18" subs on a performance level not necessarily better but on a par. It's doesn't have to do this to every 18" sub ever made it in fact only has to be comparable to one 18" sub to be a genuine statement.

I don't see how this is any different than saying this is an M+S sandwich..... this is a KK sub.

Why is it such an issue to you ?

 

 

[/quote]I already explained the issue. All things being equal, a pair of 12'd do not equal a single 18, so claiming otherwise is an issue for me.

At the point of contact the rool surround does move the same speed as the driver, decreasing as the surround moves away from the driver cone. The roll surround only form part of the suspension, and doesnt really add any weight to the driver. Kippel testing already covered all these aspects so feel free to look that up in your own time. Once again, I havent expressed any doubt in the performance of this subwoofer. Ive made a point of the comment on the cone area.

I have compared any subs. I said that a pair of 12" cones do not equal an 18, and provided the numbers that show an 18 will have roughly 25% more area than a pair of 12's. Nothing is being twisted, thats just how you choose to interpret what I post, for what ever your reasons are.

no harm in making the offer

Hi moonfly

Thanks. Any information which you feel will help.

All the best

Rick @ Musicraft

I dont understand the jump from cone area to amplification now, but yes, I have always maintained the importance of good amplification. I built a push pull sub, and yes I powered the drivers in series and parallel, though only from seperate channels of the same amp, which isnt the same as using two amps, but then do the amps in kens new subs share a common power source, because if they do its pretty much the same thing.

 

I havent heard the new subs, and I would love to because my eyes and ears are always open. I would be surprised if they did anything I wouldnt expect, but you never know. Ive never questioned their design, or Kens ability, but it seems that all you want me to post is glowing rhetoric and nothing else. You say you know this new subs destroys a 15" driver sub, but then its a generic statement as there are some very ordinary subs using 15" drivers. More cone area simply means moving more air, which translates into being louder. Because subs drop off at the low end, the louder they are the louder the low end which in turn translates into improved extension. This is the reason more cone area is a desirable trait, because for any given amount of travel (excursion), more cone area means more spl. Where things get interesting is when you begin to look at the aspect of excursion, and how the combination of that and cone area work together.

As long as you have known me, and as long as I have been commenting on sub design, I have always pointed out that a pair of 12's are generally preferable to a single 15, and a pair of 15's generally preferable to a single 18 (for reasons I wont go into). A search through my history will turn up many examples of me saying this, but again it must be maintained that during the comparison, all thing must remain equal or the comparison does not hold up. A pair of rubbish 12's for example are not preferable to a single high quality 15, and likewise, you must compare good quality 12's against a good quality 15. If kens subs are considered high end, and the drivers used are to be considered high end, then you must compare his 12 inch drivers to a high end 18 inch driver, and the 18 will have more cone area, and high end 18's have more excursion almost as a function of their design and size. Having designed and built single 18 inch drivered subs, I'd be very surprised after hearing the new KK sub, if I would take the KK sub over the single 18. Over a single 15, I'd fully expect I would take the KK sub pretty much every time.

Anything within the outer gasket will add mass to the cone. Including the resistance of the roll surround. Feel free to ask your mentor.