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Discussion Starter #22 (Edited)
This is the original, single voice-coil 4 ohm version, Thiele-Small parameters:

Fs = 17.7 Hz
Re = 3.4 ohms[dc]
Le = 6.09 mH
Qt = 0.37
Qes = 0.39
Qms = 5.59
Mms = 434.34 grams
Rms = 8.69 kg/s
Cms = 0.184 mm/N
Vas = 274.1 liters
Sd= 1029.22 cm^2
Bl = 20.51 Tm
Lp(2.83V/1m) = 91.60 dB
Xmax = 22mm

Power Handling: 800 Watts
SPL (2.83v/1m): 89.2 db
Impedance: 4 Ohm (SVC)

Recommended Enclosure Sizes:
Sealed: 4.6 cubic feet
Ported: 7 cubic feet @ 19Hz
EBS: 12.4 cubic feet @ 15Hz


I just looked at a link that had this info and a picture of that driver he had for sale it looks just like the one I have so it is the correct driver I think..

It is a Single voice coil. I was just thinking is it possible I wired the Speakon connector wrong?

EDIT: I just checked the wire on the cabinet and the speakon connector it appears to be wired properly.. I just have to pull the driver off to make sure I have the positive and negative correct..

here is a Picture of the drive I have:




the below link is how to set the inuke to 16hz with the HPF. I think the LPF is OFF??


http://www.avsforum.com/forum/155-diy-speakers-subs/1461489-how-extend-high-pass-filter-below-20hz-dcx2496.html


Thank you for helping me ;)
 

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Discussion Starter #24
Well when I bought it I was a Noob big time and sold the other driver OOPPPS!! Well I will get two next time out ;)

I will remove the Filter and see what happens.. so I will take a measurement from the MLP with the Subwoofer..

I will do that tomorrow as I have some things currently going on.. I did hook the sub back up and it was definitely hooked up correctly.. I am going to install some T-Nuts on the sub tomorrow also so I can check the polarity of the wiring to the driver..
 

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Discussion Starter #25
Well I did not get to check the sub earlier but I will try and get some Sunday.. IF I still get that dip with the HPF Off what would that indicate?
 

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Discussion Starter #30
Also, could it be something in your receiver? Do you have an old active sub you could try for comparison? You are using the receiver's sub output, right?

Regards,
Wayne
Yes I will try and see If I can rent an amp at Guitar Center or something.. Yes I am using the Subwoofer Output on my Receiver.. No I gave my old active sub to my niece..
 

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Discussion Starter #31 (Edited)
Well I was trying to get a sub measurement tonight altho I could not get it to isolate the sub to do a measurement ONLY on the sub. not sure what happened there but maybe a misconfigured REW??

I did get a measurement with the front speaker and sub from the Main Listening Position.. I still had the dip :(

Not sure what is going on but I completely took off the HPF and all the PEQ and such on the amp. I tried reconfiguring REW and I am not sure what is going on with that but could it be possible the UMIK is defective??

here is the graph:


nose dive.jpg



Here is the Box I found these after some looking around.. It states for the 18.2.2 but It also works fine for the 18.4 IXL.. This box was built by the guy from Mach 5..




ixl18-2.jpg

ixl18-1.jpg



EDIT: I did think of a trick I could try with REW.. Since the dip is at like 22hz get rew to generate that tone and check with an SPL meter built into rew and see if the dip is really there.. I am listening to the SUB and it sounds fine but I guess if I don't hear the tone that could indicate a problem.. still unsure why that dip is there in my measurement it sure ddoesn't sound like it when watching a movie or music..
 

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Well at least response is getting down to 20 Hz now. So here was a HP engaged?

As far as the dip at 22, that’s going to be an issue of the room and placement, primarily the latter. As long as you’re testing with tones , do them at 20 Hz and 30 Hz as well as 22. If they seem louder, that would confirm the dip at 22 Hz.

Do you have the sub in a corner with uninterrupted walls in both directions? That typically gets the fewest nulls.

Regards,
Wayne
 

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Discussion Starter #33
Yes I did have the HPF on but it had the -4 shelf to go lower down to 16hz.. I guess either that trick did not work or I had it set wrong?? But it was a thread over at the other forums I think I linked it back a few pages..

I have the sub in the rear right wall facing into the room.. I tried facing the driver into the wall and the measurement was still the same.. Do you think I should move it to the front of the room??
 

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Discussion Starter #35
Not sure what “in the wall” means, but if you have it in the middle of a wall that’s probably the worst thing you can do for both response and extension. Try a corner as described in my previous post.

Regards,
Wayne
I stated "Into the Wall" meaning the driver was facing the wall.. Should I try and move it to the front of the room.. I have it in the rear right wall with the driver facing into the room.. it is an enclosed room with uninterrupted walls..

Not sure why there is a dip but I did move it and the dip was the same with no change..
 

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Discussion Starter #36
I am going to do the SubWoofer Crawl with Pink Noise and my RS SPL Meter. Hopefully it will reveal a better placement and IF I have to move it I need to get a longer SpeakOn cable..

I will do this tomorrow.. Thank you for all the help so far.
 

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Discussion Starter #37
I do have 1 question, when I do the subwoofer crawl am I supposed to set the subwoofer in the MLP??

If so that is going to be a bit hard as my subwoofer is VERY Heavy and I don't think I can put it on the sofa??
 

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There’s no good reason to do the subwoofer crawl if you have REW. It’s not terribly reliable anyway. Your best bet is to put the sub at the listening position and use REW’s RTA function that shows a graph in real time. Then move the mic to any potential sub locations and see how the graph reads.

BTW, no need to put the sub on the sofa. It should be good enough to move the sofa and put the sub where you’d be siting.

Regards,
Wayne
 

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Discussion Starter #39
Well I may do this when my Brother inlaw comes over Saturday and he can help me move the sub and couch ;)

I was going to do the Subwoofer Crawl with the SPL Meter. would it still be better to do it with Rew??

If I did the subwoofer crawl with Rew do I run the sweeps from 10-600hz then see what the graph looks like with the mic in the new possible sub location around the room??
 

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SPL meters only measure noise. The location that gets the highest SPL might merely be the location with the highest spike (i.e. peak, room mode) in the response curve. Plus, there could be a severe null to go along with it, which wouldn’t show up at all.

What you want is the location with the least difference between peaks and troughs in response. REW will tell you that. Using the RTA is faster, but sweeps will work just fine.

Regards,
Wayne
 
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