Jay481985 Posted July 28, 2009 Author Share Posted July 28, 2009 I don't have it yet, looking for a person to make me one. It will be a 24 inch cube. triple 18 in prs Contact Kyle, he is back with Thilo and they are supposed to be back soon. Quote Link to comment Share on other sites More sharing options...
DrWho Posted July 28, 2009 Share Posted July 28, 2009 Can you post a plot where the scale is from 10Hz to 200Hz and from 75dB to 105dB? It will make your frequency response look nasty, but will be more reprentative of what's going on. But even then, the shape of the frequency response curve doesn't tell you much about the perceived sound quality. I've got a single 12" driver with a 250W plate amp that measures quite similar to your plot, but I can guarantee that they won't sound the same. Although, I might argue that in the same room that they will sound more similar than dissimilar until the SPL gets high enough to cause the weaker system to distort. Even with the most insane subwoofage, the room dominates much of the sound. Also, you can move the mic a few feet or even a few inches and the response can change quite dramatically. Quote Link to comment Share on other sites More sharing options...
robertcharles Posted September 29, 2009 Share Posted September 29, 2009 These are the first graphs from my new REW setup. I am working the bugs out, but this is what you asked for? Yes/No? Quote Link to comment Share on other sites More sharing options...
DrWho Posted September 29, 2009 Share Posted September 29, 2009 Yea, that's unsmoothed right? Is there any dimension in yourlistening space that is about 75 feet long? The two dips right next toeach other around 16Hz could be your tuning not keeping aligned withyour active drivers. Do you have any stuffing in your cabinets? Youmight need to push the tuning a bit higher to get rid of that dip. Thedip itself isn't so bad, but I have a feeling your actives could beunloading early which will result in excessive cone motion for the sameSPL....not that excursion is particularly a problem in your setup, butfixing it should lower the distortion. Of course that's allpurely speculation at this point....an outdoor measurement wouldprobably be more informative (albeit a lot more work I'm sure). An impedance plot would be interesting too. Areyour subs not positioned in corners? And these are sub only plots right? Quote Link to comment Share on other sites More sharing options...
robertcharles Posted September 30, 2009 Share Posted September 30, 2009 Yep. Unsmoothed. The cabinets are along a side wall. When measuring, I measured at listening position. I will measure ground plane, but this will only be on one baffleor the other. I could also measure on the side of cab with no direct driver passive radiation. Subs only. I will set the REW up and run a few suggestions if you don't mind. I really do not get any room gain. The graph looks very much like the model that I used to build the cabs. They are pretty much stuffed. The tuning is at 14.2 Hz. Quote Link to comment Share on other sites More sharing options...
robertcharles Posted September 30, 2009 Share Posted September 30, 2009 My room is 20 wide, 30 long, and 8 feet high. I will say, I do not really ever get excessive cone movement. I get tremendous SPL levels and the cones are always moving well within xmax. I have seen the LMS drivers going to max in a demo, and I am in no way even coming close to xmax-I do not know if I would even want to approach those levels. Quote Link to comment Share on other sites More sharing options...
robertcharles Posted September 30, 2009 Share Posted September 30, 2009 The new graph is going through a crown itech 8000. The old graph a few months back was from an old alesis. I think the crown has a built in rolloff at 8 Hz. I am going to use a different amp to do measures to compare. Quote Link to comment Share on other sites More sharing options...
DrWho Posted October 1, 2009 Share Posted October 1, 2009 The point isn't that you run outta xmax, but that excessive cone motion for the same SPL creates distortion. I don't think I'd worry too much about the performance below 8Hz or even 15Hz for that matter. Quote Link to comment Share on other sites More sharing options...
robertcharles Posted October 1, 2009 Share Posted October 1, 2009 I follow you on that. My point is that I have seen an LMS running all out and it was quite impressive. I have not even come to 2/w3 of what I saw the LMS do in the demo and I have way more than enough from the setup as is. I am trying to get set for some AB measures to see what is going on. I might need a little input. Thanks, Robert Quote Link to comment Share on other sites More sharing options...
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