Paducah Home Theater Posted January 14, 2016 Author Share Posted January 14, 2016 (edited) Didn't check that yet, did check the wiring, the voice coils are all in series and running stereo into just one of them even outside of the box did the same thing. That should be a minimum 4 ohm load but if you look at the impedance curve probably closer to twice that or more. Did wire up a 9v battery to all of them, they're all in phase and the cones move about the same amount. See if you can view this video to see what I'm talking about. That ain't right. Intro to "for whom the bell tolls". http://vid1375.photobucket.com/albums/ag469/metropolislakeoutfitters/20160113_225120_zpsoszke6vr.mp4 Edited January 14, 2016 by MetropolisLakeOutfitters Quote Link to comment Share on other sites More sharing options...
derrickdj1 Posted January 14, 2016 Share Posted January 14, 2016 (edited) One of the things wrong with the previous graph is that it was done at to low a volume. The sweeps should be done around 35 or 40 db over ambient room noise. Here is a link that our local guys use for subwoofer integration and REW. They are not to long or hard to follow. We had an REW class at the last gtg and this should point you in the right direction. There is a video of the REW class. I hope the amp is not damaged. http://www.avsforum.com/forum/155-diy-speakers-subs/1713458-mtg90a-s-multiple-subwoofers-mains-integration-how-thread.html http://www.avsforum.com/forum/91-audio-theory-setup-chat/1449924-simplified-rew-setup-use-usb-mic-hdmi-connection-including-measurement-techniques-how-interpret-graphs-3.html#post22823228 The REW link will go over setup, smoothing, taking readings and some good do's and don't. My concern over amp/driver damage was one of the reasons in a recent thread that I said we talk about watts to much and should be discussing voltage. Edited January 14, 2016 by derrickdj1 Quote Link to comment Share on other sites More sharing options...
Paducah Home Theater Posted January 14, 2016 Author Share Posted January 14, 2016 (edited) Derrick what do you think about that stupid sounding noise? WTH is that? I had it low because everybody else was sleeping plus doing loud sweeps rattles stuff. Edited January 14, 2016 by MetropolisLakeOutfitters Quote Link to comment Share on other sites More sharing options...
derrickdj1 Posted January 14, 2016 Share Posted January 14, 2016 (edited) I watched the video. I think something is wrong with the amp. The pro amps can be damaged doing really low stuff and since waves. I only use the short sine waves with Omnimic. Movies are one thing but, sine waves can really stress the driver/amp. Ship it back to tomorrow if it is under warranty. I had a Chase driver blow. I am not sure if it was defective or if I caused the problem playing Real Traps testones loud in the 10-20 Hz range. These low tone can damage the driver suspension. At that time I had no appreciation of voltage regulation. Edited January 14, 2016 by derrickdj1 Quote Link to comment Share on other sites More sharing options...
Paducah Home Theater Posted January 14, 2016 Author Share Posted January 14, 2016 (edited) I think something is wrong with the amp. The pro amps can be damaged doing really low stuff and since waves. Holy cow, it just occurred to me that right before I installed the last two subs, I played an 18 hz sine wave for 30 minutes in free-air in an attempt to break them in in order to better match the ones I've had for a year as those were pretty loose comparatively and sounded bad when I first got them. That was just Friday night. I've played this video 3 times since then and it never did seem right. I'm going to go throw up now. Edited January 14, 2016 by MetropolisLakeOutfitters Quote Link to comment Share on other sites More sharing options...
CECAA850 Posted January 14, 2016 Share Posted January 14, 2016 (edited) I played an 18 hz sine wave for 30 minutes Nothing wrong with that at low volumes. I would think the drivers would thermal before the amp but I've never done that. Edited January 14, 2016 by CECAA850 Quote Link to comment Share on other sites More sharing options...
derrickdj1 Posted January 14, 2016 Share Posted January 14, 2016 (edited) Nothing wrong with that at low volumes. Low volume is the key, lol. But, using sine wave for fun can get you into trouble. My problem is when testing the subs, I run them pretty hard.. I guess I go overboard at times. Edited January 14, 2016 by derrickdj1 Quote Link to comment Share on other sites More sharing options...
Paducah Home Theater Posted January 14, 2016 Author Share Posted January 14, 2016 I played an 18 hz sine wave for 30 minutes Nothing wrong with that at low volumes. Yeah, it wasn't really super low volume. Actually it was zero volume but not really low power. Seaton told me to run them at 3/4 usable travel. I didn't get quite that much, my laptop started distorting and I think an amp limiter kicked in, had to back off. I ran them as hard as I could without the electronics sounding like they were going to break. Maybe they broke anyway. Quote Link to comment Share on other sites More sharing options...
Paducah Home Theater Posted January 15, 2016 Author Share Posted January 15, 2016 got granite? Need some cleanup and maybe some wedges. Quote Link to comment Share on other sites More sharing options...
derrickdj1 Posted January 15, 2016 Share Posted January 15, 2016 (edited) The sine waves were used to break in the drivers? I just let them break in naturally with movies and music. I have to recalibrate the system in 6-8 week once the suspension breaks in and again around 3 months. The granite gives a nice look to the front stage! Edited January 15, 2016 by derrickdj1 1 Quote Link to comment Share on other sites More sharing options...
Paducah Home Theater Posted January 16, 2016 Author Share Posted January 16, 2016 The sine waves were used to break in the drivers? Well it wasn't my idea. The amp should have been able to handle such things. Quote Link to comment Share on other sites More sharing options...
derrickdj1 Posted January 16, 2016 Share Posted January 16, 2016 How many amps are you using and what types? I think you said the 4 subs where wired in series? Quote Link to comment Share on other sites More sharing options...
Paducah Home Theater Posted January 17, 2016 Author Share Posted January 17, 2016 The 2 ohm voice coils are wired in series. Two groups of two subs are wired in parallell. Should be stereo into a nominal 2 ohm load, but if you look at the impedance curve, it is usually quite a bit higher than that, like double anything above 10 hz. It does the same thing into just one at 4 ohms. It is a crown 2502. Worked fine except for high level single digit stuff until now. The limiters kick on too easily and you can't override them like you used to be able to. Quote Link to comment Share on other sites More sharing options...
derrickdj1 Posted January 17, 2016 Share Posted January 17, 2016 Wiring the subs is always a little tricky: I have wired a couple wrong and didn't catch it for a month. I couldn't figure out why the amp was not tolerating things well. It may be worth double checking the wiring before putting the repaired amp back in duty. Currently I have everything wired to a 4 ohm load. It make things easier to switch in and out. Quote Link to comment Share on other sites More sharing options...
AllenTacey Posted January 17, 2016 Share Posted January 17, 2016 I'd Google how to build large tube, 12 to 15 inch diameter tubes three to four feet long which can be cardboard. The short story is no distortion introduced by a tube which has equal flex from all sides and does not but it is nice to use long throw driver and no special needs for crossover. That is what I'd do if a subwoofer is really needed. Fortunately a pair of Klipsch reference speakers does not need anything but right and left speakers properly placed. Quote Link to comment Share on other sites More sharing options...
Scrappydue Posted January 17, 2016 Share Posted January 17, 2016 I'd Google how to build large tube, 12 to 15 inch diameter tubes three to four feet long which can be cardboard. The short story is no distortion introduced by a tube which has equal flex from all sides and does not but it is nice to use long throw driver and no special needs for crossover. That is what I'd do if a subwoofer is really needed. Fortunately a pair of Klipsch reference speakers does not need anything but right and left speakers properly placed. your a little late to the party. not only has the "ultimate" sub already been built but they have already damaged his amp just messing with you cory 2 Quote Link to comment Share on other sites More sharing options...
Ceptorman Posted January 18, 2016 Share Posted January 18, 2016 I'd Google how to build large tube, 12 to 15 inch diameter tubes three to four feet long which can be cardboard. The short story is no distortion introduced by a tube which has equal flex from all sides and does not but it is nice to use long throw driver and no special needs for crossover. That is what I'd do if a subwoofer is really needed. Fortunately a pair of Klipsch reference speakers does not need anything but right and left speakers properly placed. your a little late to the party. not only has the "ultimate" sub already been built but they have already damaged his amp just messing with you cory I had to laugh. Quote Link to comment Share on other sites More sharing options...
Paducah Home Theater Posted January 18, 2016 Author Share Posted January 18, 2016 (edited) Messed with it more last night, it does seem as though I broke the amp. The load on each channel is about 2.4-2.5 ohms nominal which is about what I expected. They're rated at 4.4 ohms dc with the voice coils in series, take two in parallel and that's 2.2. Not sure where the extra 0.2-0.3 ohms came from but I doubt that's anything to be alarmed about. Anyway, its making this sound even with just my phone feeding the sub amp. No matter what kind of music, there is this high pitched distorted concussive hit right before any big hit of bass except for real low frequencies, and does this even at pretty low volumes. Metallica's kick drum as well as DJ Magic Mike does the same thing. Just really weird, almost like the internal capacitors that it gets peak power from is fried. Amp is boxed up and it is shipping out today. For now it will just have to look pretty. Edited January 18, 2016 by MetropolisLakeOutfitters Quote Link to comment Share on other sites More sharing options...
CECAA850 Posted January 18, 2016 Share Posted January 18, 2016 Bummer. Quote Link to comment Share on other sites More sharing options...
Pete H Posted January 18, 2016 Share Posted January 18, 2016 If I missed this, sorry, but these are sealed boxes and I'm sure that you've checked for leaks, but high pitched concussive sound is exactly how I would have described the air leak in my RSW 15 when I put it back together. Hope that it's something as simple as that, but great project. You'll find it and be pumping out clean bass in no time I'm sure. Quote Link to comment Share on other sites More sharing options...
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