Scrappydue Posted March 31, 2014 Share Posted March 31, 2014 Scrappy, why did you mention basement? i mention basements because although with 4 18's in my basement, the amount of shaking and "waving" my svs ultra's did up stairs in my COMPLETELY suspended floor was just incredible. still awesome on the 4 18's with more pressure and force, but the concrete don't move. still can shake my couches though. but upstairs was just…different Quote Link to comment Share on other sites More sharing options...
Scrappydue Posted March 31, 2014 Share Posted March 31, 2014 you guys are nuts. ...Four 18's... id say we are very normal. go over to avs where guys like popalock have 16 18's to accompany a rf-7ii theater and others with even more!! Quote Link to comment Share on other sites More sharing options...
Scrappydue Posted March 31, 2014 Share Posted March 31, 2014 get a mic and learn REW / dial in etc. thats where the real fun is. id be careful with running that 6db boost as derrick mentioned with out actually knowing what your room is doing for you. really easy to get used to something like that and it be too much. i cut by 6.5 db at 20hz!! you could be killing your headroom without even knowing it. once you get a mic and do a sweep with no eq at all you will have a better idea of where you need to boost. Quote Link to comment Share on other sites More sharing options...
holtrp Posted March 31, 2014 Author Share Posted March 31, 2014 Couple of other random thoughts here. The shipping issue didn't go my way. As near as I can tell, shipping to Alaska just happens to be about twice as expensive as shipping from Alaska. Still, I am happy I ordered from Parts Express through Amazon which saved me about 30%. A handy trick for anyone else looking to buy. All in, this setup is still much less than cost + shipping on a pair of SVS PB13 ultras and obviously the value just goes up the closer you are to Ohio as shipping goes down. I have to go back to work tomorrow for two weeks, but should be able to read up on mics, boundary gain and room effects to get some ideas of what is going to look / sound the best over time. I will probably ultimately tune these things in around -15 or -20 or a tad lower as that is usually the upper end for me for normal listening. I am interested in playing with the DEQ as Derrick mentions that you can get some decent results at lower volume levels with that adjustment. Many people have complained about the fan noise of the iNukes. I measured it at 45db at the listening position which isn't bad considering I have a cold air return vent that generates about 70 db when the furnace is on. I am sure over time the fan noise will grate on me, but I am not going to do anything about it for the foreseeable future. I would rather keep the warranty intact for now and once I remodel, everything should be hidden anyway. Wish I had more time to blast these things. Bathroom remodel, kids birthday party and some other projects really put this on the back burner. Hopefully in the next month or so I can get some charts put together. Quote Link to comment Share on other sites More sharing options...
derrickdj1 Posted March 31, 2014 Share Posted March 31, 2014 (edited) If I am correct, these are sealed subs. They should not be bottoming out. Level match each sub to 72 or 73 db. one at a time for the main listening position. Then run autocalibration. Note where autocalibration sets the subs, as far as minus or plus numbers. The sub Ideally should be between -3 to +3. This will leave plenty of room in the avr to increase or decrease sub volume. If all this was done, then in the PEQ cut the bass boost 3 db. One note on sealed subs, because they witl reproduce the sub 20 Hz frequencies down to around 10 Hz or lower, they can quickly eat up amp wattage. Every 3 db boost cuts amp power in half below 30-35 Hz depending on the roll-off of the driver/sub. I have up'ed the avr trim by 10 db. The bass was way off balance. Also, trying to get more low end works to a point and then the top end is decrease and less chest slam. Also, excess bass boost will not increase the tactile response. Excessive bass boost leads to driver compression, decrease efficieny and no increase is spl. Most of what you are getting under 20 Hz is the room gain component. An overly damped system will have less distortion, better chest slam and great SQ. On my amps the gain is around 9-10 O'clock. I know all rooms are different but my basement suck up sound and is still larger that I would like for the HT area, around 5300 cu ft. Usually when the clip light comes on blinking, that means you have around 3-5 db more to go before amp shut down. A continous clip light means you are there, and if left there to long, the signal will clipped which can lead to driver damage from over heating the voice coil. This senario will usually occurs before mechanical failure. Most of the room gain is room rumble and no increase in sound quality. Asymmetrical sub locations will excite different room modes and lead to a better room response. Symmetrical location reinforce the same mode and causes larger peaks and deeper nulls. A crude frequency graph can be done by downloading Real Traps, test tones. Use a Radio Shack correction table to adjust the graph appropiately. For example, a spl of 80 db with the analog Radio Shack meter corrects to 100 db with the table at 10 Hz. I like to eq all the subs as one since bass frequencies are so long and the subs are acting as one unit in the room. Auddysse XT or 32, 128 vs 512 filters or resoultion, works well with PEQ done before or after autocalibration. The manufactures recommends PEQ befor running Auddysse since PEQ dose nothing in the time domain. This is also a consideration since Auddysse will apply a bass boost at the sub/s -3/+3 db point. In other words more caution using bass boost with Auddysse, compared to YPAO or MCACC. MCACC works best if the PEQ is the last step done after autocalibration. Edited March 31, 2014 by derrickdj1 1 Quote Link to comment Share on other sites More sharing options...
CECAA850 Posted March 31, 2014 Share Posted March 31, 2014 If I am correct, these are sealed subs. They should not be bottoming out. They have less than 13mm of xmax. Why do you think they won't bottom ou? 1 Quote Link to comment Share on other sites More sharing options...
holtrp Posted March 31, 2014 Author Share Posted March 31, 2014 (edited) Most people think that the Xmax for these drivers is extremely conservative. Yes, all 4 are in sealed boxes. Not entirely sure, but one either bottomed out or was very distorted during the lighting scene from war of worlds. Everything else was off and I was just playing with one sub when it made that grinding sound and the clip light came on. Gain on amp was about 75%, subs 4db hot from AVR. Fine tuning is absolutely in order. Not really looking for maximum SPL, but just flat response and even. Ideally, and I think this is normal, I would just like to know the ranges I can play with and hopefully get to the point where I can have all the control I need from the sub +/- on the AVR only. I really need a solid 6 interrupted hours with no distractions to eq these things. Wife will be out of town next month for about 4 days, so if I can convince grandma and grandpa to take the boys for a night, I will have a great chance to really dig in. Edited March 31, 2014 by holtrp 1 Quote Link to comment Share on other sites More sharing options...
derrickdj1 Posted March 31, 2014 Share Posted March 31, 2014 Grinding means the one sub was under stress. Adding in a second sub doubles the power(+3 db) and the two subs will be mutually coupled(+3) or a total gain of 4-6 db depending on what frequency one is looking at. Fours subs means you dramatically increase the systems headroom. Turn the gain down for sure. I don't know what autocalibration system you use and if it applies a bass boost to the subs. 1 Quote Link to comment Share on other sites More sharing options...
CECAA850 Posted March 31, 2014 Share Posted March 31, 2014 A driver that's bottoming out will make a CLACK CLACK CLACK mechanical sound. You may have been hearing your signal clipping. Quote Link to comment Share on other sites More sharing options...
derrickdj1 Posted April 1, 2014 Share Posted April 1, 2014 (edited) If I am correct, these are sealed subs. They should not be bottoming out. They have less than 13mm of xmax. Why do you think they won't bottom ou? I should of have worded the bottoming out statement better. I thought he was running four subs and not one. With four of them running in a properly calibrated system, the subs should not bottom out. I am not saying that they cannot be forced to bottom out but, in a sealed sub compression and distortion should appear first. This is why I caution on the use of bass boost of more than 3-6 db in the 20 Hz and under frequencies. Piston travel may force things past the magnet structure of the driver and stress the spider and support attachments. Large or small, physics remains the same for subwoofers. Carl, it woud be interesting to know the peak displacement of the Dayton, SI and Chase driver. I guess it can be calculated but, I am lazy, lol. Edited April 1, 2014 by derrickdj1 Quote Link to comment Share on other sites More sharing options...
holtrp Posted April 1, 2014 Author Share Posted April 1, 2014 Sorry about the confusion. I have 4 Dayton subs all in individual seal enclosures. When I was testing everything out and heard the grinding, I only had one sub turned up with all the other amps turned off. Quote Link to comment Share on other sites More sharing options...
beeker Posted April 1, 2014 Share Posted April 1, 2014 (edited) Awsome reading here all! One comment if you will see the subs use veneer or finish of your liking if not duracoat them black for protection. I have my radians in each front corner with new custom triple 3" vented 200lb corner shaped enclosures with built in dollys and carpeted and screens to match my klipsch pa stuff for use outside the house if needed. Im a black finish klipsch collector anyhow so they fit right behind my chorus ii with my kpt 2602c's on top of the c2's. All goes together preatty well. Once again thank you for all the reading/notes etc...4 of these daytons may be top choice for any theater let alone any consideration of budget high or low. Great job! They are still breaking in. I wouldnt apply a the final tuning of the sub system for some time as well as use them all the same always just to maintain the equal quality of each sub. Just my opinion. A little playing around is normal although all 4 after an identical period of break in to all 4 will provide superior match in the final settings. I have followed this from my days of installs with up to 32 15's in spl comp which also sounds very good at least with my experience when done properly. Just my opinion dont throw stuff at me lol its a sweet read and setup nonetheless/regardless edit; 32 15's not 18's Edited April 1, 2014 by beeker 1 Quote Link to comment Share on other sites More sharing options...
derrickdj1 Posted April 1, 2014 Share Posted April 1, 2014 Good discussion is fun. Quote Link to comment Share on other sites More sharing options...
The Dude Posted April 1, 2014 Share Posted April 1, 2014 A driver that's bottoming out will make a CLACK CLACK CLACK mechanical sound. You may have been hearing your signal clipping. That's kind of what my Velodyne does, kind of a clack or a pop kind of sound. It only happens on those real low frequencies, like in the canon seen on the Hulk, some times hand gun fire. Quote Link to comment Share on other sites More sharing options...
CECAA850 Posted April 1, 2014 Share Posted April 1, 2014 Once you hear one bottoming out, you won't forget the sound. Quote Link to comment Share on other sites More sharing options...
CECAA850 Posted April 1, 2014 Share Posted April 1, 2014 (edited) Carl, it woud be interesting to know the peak displacement of the Dayton, SI and Chase driver. I guess it can be calculated but, I am lazy, lol. It should be 2 times Sd times vas shouldn't it? I remember calculating my IB's displacement when I built it and the combined 4 drivers displaced 27 liters. 4 of the new Ficaraudio drivers displace 28 liters. Edited April 1, 2014 by CECAA850 Quote Link to comment Share on other sites More sharing options...
CECAA850 Posted April 1, 2014 Share Posted April 1, 2014 Dayton 18" HO has an Sd of 1164 cm2 and an xmax of 12.75mm. I get a displacement of 2.968 liters per driver. That makes a total displacement for 4 drivers of just under 12 liters (11.872). Quote Link to comment Share on other sites More sharing options...
derrickdj1 Posted April 1, 2014 Share Posted April 1, 2014 Thanks Carl. The clacking is noticeable. I have heard it on some utube videos a while back. I have never bottom out a sub but, all of the other subs in the past had built-in limiters. I have burned out a voice coils before, lol. The speaker was still under warranty and the driver was replaced for free. I love the picture of your IB sub. You have a lot of displacement. I need to calculate my displacement. Peak volume displacement is a good number to look at for subwoofers. Quote Link to comment Share on other sites More sharing options...
holtrp Posted April 2, 2014 Author Share Posted April 2, 2014 (edited) Here's what data bass says about them: "The driver does not have a huge amount of displacement but it is certainly has more powerful low bass output than the geometric 12.75mm xmax rating might suggest. An effective useful excursion rating would likely be more like 18-20mm." I really don't know enough to speak intelligently about the xmax, xmech, q, or any to the other metrics associated with subs. All I know for certain is that these things absolutely have delivered the low end I have been looking for. Totally reminds me of my two 15 ID q's in my old toyota Tacoma ext cab. Sitting at the airport, it's going to be a long two weeks waiting to play with them again. Any thoughts on outboard USB sound card and mic combos? Sort of lame behringer software is only able to run on PC, luckily I have my work computer for that. Looks like REW works on iOS. I want to flesh out an actual procedure for tuning these subs as I am prone to just making adjustments and playing around. Edited April 2, 2014 by holtrp 1 Quote Link to comment Share on other sites More sharing options...
derrickdj1 Posted April 2, 2014 Share Posted April 2, 2014 (edited) I don't use REW or other similar products. I just plot a FR graph using the Real Traps test tones. With there download, a paper graph is included. Then I correct the graph with the Radio Shack correction tabel and and look for peaks or diips. The correct them in the Berhinger amp. Relatively simple, free and quick. I only cut 1 or 2 peaks and boost the 20 Hz region. My Pioneer MCACC does nothing to the sub under 63 Hz. This is why it is safer for me to boost 5 or 6 db compared to people with an Auddysse system. Auddysse boosted the bass 10 db in a graph of a Chane SBE sub(formely Chase). Auddysse XT and XT 32 were pretty good for getting a flat FR. Carl IB sub is the next level above our subs. After all, it is Infinet! Ask him to for a link to look at his room. With IB subs, the box size of the sub is the whole adjacent room or attic, lol. Edited April 2, 2014 by derrickdj1 Quote Link to comment Share on other sites More sharing options...
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