Rerurn to Romy the Cat's Site

Merlin wrote:

Romy, if you see my post you will notice that I mentioned I did not know of any drive units that could successfully be employed. Can you list some? Here is a typical high quality 15" cone - indeed one of the finest on the market today. It is interesting to see the behavior above 500hz.

Merlin, I did not have 1500 I had 1400 drivers, still they essentially according to the subject of given discussion behave the same. You are a right and most of 15 inch drivers run all the  away up. The problem with them is not excessive high frequency but the fact is that a above certain frequency they produce very bad quality high frequency. For instance 15 inch Altec/JBL type of the drivers might be used up to 500 Hz, as they use in the commercial installations of those manufacturers, however from my point of view those drivers do not have good sound above 150-200 cycles. The drivers should be rolled off by other means, using extra 0.5 crossover, or narrowing down the horn’s mouth if the are horn-loaded or by any other means, that BT might be a cause off as your own problems…

What I usually see is not the excessive second harmonics but rather unpleasant quality of reproduction of higher harmonics. If cross a 15 inch driver at I would say 100 cycles, then I find mostly survivable what that driver does at 200-300 Hz, but the sound of the driver at 500-1000Hz is what bothers me. I know, I know it is a quite few dBs down but I still found it out auditable.

Anyhow, I can not directly answer your question as I do not know any good 15 inch drivers which have natural roll off at 200 cycles, as they rather should be MADE to roll off. The selection of the methods to roll them off should be viewed at each given case, and yes, in some cases it is impossible.

Merlin wrote:

Sorry wrong attachment but as your software does not allow for editting, I can't be bothered to link to the correct one. Suffice to say - plenty of second harmonic and nasty break up modes.

I have fixed it. The posters, as now should be allowed to I edit on posts with the “new” forums. You still might repost the file you intended to post. Alternately, since your file is a graphic file, you can embed the image in the body of your post, hosting the image of my server, and using the following instructions:

http://www.goodsoundclub.com/Forums/ShowPost.aspx?PostID=1120

Rerurn to Romy the Cat's Site