jeffl
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Posts: 27
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Post by jeffl on Apr 17, 2016 13:50:46 GMT -7
Can I put a manifold in a closet like this? I couldn't access Mikes list of drivers so not sure on options. I have a ep2500 so id like to use it to start heres AE's IB18HT-4ohm. Better options out there, any help appreciated. Area with couch is 24' long and room with closet is 16' long, they didn't show up Fs: 18.38 Hz Qms: 5.7 Vas: 632.1 L Cms: .3 mm/N Mms: 250 g Rms: 5.03 kg/S Xmax: 18 mm(peak) Xmech: 25 mm(peak) Sd: 1218 sqcm Vd: 4.38L (p-p) Qes: .63 Re: 2.8 ohm Le: .41 mH Z: 4 ohm Bl: 11.31 T/m Pe: 500W (cont.) Qts: .57 1WSPL: 89.92 dB 2.83V: 94.48 dB Attachments:
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Post by ThomasW on Apr 18, 2016 6:49:34 GMT -7
Hi,
The driver list is years out of date so I disabled the link until I have time to update it.
Yes the closet will work, you'll probably have issues with the doors rattling. That can be fixed.
John makes excellent drivers. For IB use we need multiples so the AE option gets spendy pretty fast.
The driver most frequently used is the Fi Car Audio 18" IB3.
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jeffl
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Posts: 27
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Post by jeffl on Apr 18, 2016 10:13:54 GMT -7
Thanks for replying Thomas. I did see the Fi being vary popular because of excursion. I basically just going to be out of pocket for speakers so I don't mind a few extra dollars if its an improvement and not splitting hairs. I was thinking 2 drivers in 2 manifolds, one left and right of the tv, this is were the 2 subs are placed now and have a fairly flat response besides a small peak at 40hz. Provided my framing allows should I place them in the same area.
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Post by ThomasW on Apr 18, 2016 22:14:19 GMT -7
Hi,
Distortion in very low bass isn't especially audible unless one has one of the Rotary Subs. Tom Nousaine did all his power/output testing at 10% distortion levels claiming 10% was not audible. I don't know about that I don't have equipment set up for that kind of testing. But perhaps ultra low distortion motors aren't as useful for subs as they would be for pure woofers.
Fi are popular because they are very good drivers for the money. Pwesonally I'd want a little lower Q but that's just me.
Yeap the place for the IB drivers sounds fine since it works for the existing subs.
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jeffl
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Posts: 27
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Post by jeffl on Apr 20, 2016 17:02:07 GMT -7
Looking forward to starting a build thread. I hope to order drivers in next couple weeks, until then I have plenty of info to read here, even considering Ive spent 8 hrs reading here already. thanks for the help and the site.
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jeffl
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Posts: 27
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Post by jeffl on Apr 23, 2016 18:18:52 GMT -7
Ive decided to use the Fi 318's with a ep2500. Starting with 2 and moving to 4 most likely. Am I better off getting the 2 ohm or 4 o?hm versions
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Post by ThomasW on Apr 23, 2016 21:10:23 GMT -7
You want to end up with a final load of 4 ohms per channel, so start with 2-2 ohm drivers and buy buy 2 more 2 ohm drivers to create series wired 4 ohm pairs.
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jeffl
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Posts: 27
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Post by jeffl on Apr 24, 2016 3:50:21 GMT -7
Ok, I see quite a few people with one manifold, I currently have 2 subs at left and right of front. If I feel 2 aren't doing it, am I better off building a 2nd manifold in the other sub placement or future proofing the original manifold for 4.
I have room to space them about 7' apart. My end game is to have a media/HT room in the room with the closet, so the closet will be the front for IB setup for that room, basically flipped from current setup. Im trying to think ahead and not make anymore work than necessary. Although I may do a line array in that room because I need to do some build out anyway.
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Post by ThomasW on Apr 24, 2016 7:35:48 GMT -7
Since you didn't post pics here I didn't know about the side walls. Those are probably your best bet. A piece of plywood would seal off the electronics rack from the rearwave of the IB. Any big sub, IB or other in the room will cause some components of the AC to vibrate. Those vibrations can be dealt with. Do you have measurements of the sidewall location but further to the front of the room?
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jeffl
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Posts: 27
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Post by jeffl on Apr 24, 2016 15:34:20 GMT -7
? That's not my room..... in my drawing in first post, I did not show it but my subs are just outside my L&R mains. I guess my main question does an IB with 4 drivers in one location still have the same issues as a moveable unit with one or 2. Does massive displacement in one spot improve a response? Im not opposed to doing 2 manifolds, Im inclined to build the second one and save it until it may or may not be needed, or I decidedly need 8
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Post by ThomasW on Apr 25, 2016 6:33:46 GMT -7
Oops sorry that was supposed to be in 1stCav's thread.... Since your room is comparatively small I don't think you'll need 4 drivers. unless there's too much loss out of the front/side opening. Overall audio performance would be improved significantly if that opening were closed, say with a 36" solid core door and a partition wall. 2-2 driver manifolds or a single 4 driver unit won't matter much given the 12' width of the room. You will need to put 'super chunk' style bass traps in the rear corners.
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jeffl
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Posts: 27
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Post by jeffl on Apr 26, 2016 16:23:26 GMT -7
Thanks Thomas
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Post by ThomasW on May 1, 2016 19:17:21 GMT -7
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jeffl
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Posts: 27
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Post by jeffl on May 20, 2016 14:27:47 GMT -7
Drivers should be here Tuesday, getting stuff together this weekend. Going to build the manifold if I have time. Ultimately I want to be measuring and dialing in on memorial day. Ill post when my drivers arrive or the manifold is installed whichever comes first.
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Post by ThomasW on May 21, 2016 5:35:42 GMT -7
Good news, looking forward to seeing some progress with this project ...
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jeffl
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Posts: 27
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Post by jeffl on May 22, 2016 4:31:32 GMT -7
I eneded up having drivers made to see if another viable option for IB could be available. Time will tell if I through my money out the window. Here are the specs, Im a lil unsure of the size for the manifold for 2 18" drivers Heres the specs and a pic revc 2 ohms fs 18hz qts .65 qes .77 qms 4.4 le .93 mH vas 9.4 ft^3 sd 1017.3 cu in @ 4" p-p sens 85.5 db 1w1m pe 1000 watts, can handle 1500 spl 91.1 db @ 2.83 vrms Bl 13 Tm xmax 25mm displacement 907.4 cu in xmech 100mm p-p
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Post by ThomasW on May 22, 2016 6:18:52 GMT -7
Strange looking driver, I've never seen such a huge surround that only has a 25mm claimed Xmax
Unlike ported or small sealed boxes there are no IB box calculations that require the T/S parameters. For a manifold the design is simply based on making a box that's physical design fits the size of the drivers and the opening or space where the manifold will be placed.
So......
With 18" drivers the manifold is usually 21"-22" on the sides where the drivers are mounted with an opening into the room sized to the stud spacing of the wall
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jeffl
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Posts: 27
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Post by jeffl on May 22, 2016 7:11:23 GMT -7
I asked about that, he said he doesn't use bl corrected xmax figures . With the xmech at 100mm im assuming, and I hate to do that, ill be getting more than 25mm without a problem. picked up wood this morning, so it begins
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jeffl
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Posts: 27
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Post by jeffl on May 23, 2016 2:14:26 GMT -7
My drivers are 2 ohm 1000 watts...Concerning power, I was planning to run a driver per channel on the ep2500 with a miniDSP in the chain. Is it ok to use a y splitter, I have 2 sub pre-outs, but I have a sub that I was going to use to at lower volumes to fill in my nulls provided it doesn't muck up the sound of the IB.
Or do I need another amp. I feel eventually( maybe shortly) Ill add another manifold and dump the box sub, which If I wire the same I would need another y splitter of the second pre out. Being each set of drivers is in their own manifold the splitter shouldn't matter should it?
I cant wire in parallel for a 1 ohm load, and I know in series will get me 4 ohms but is not the best choice... sorry for the scattered thoughts
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Post by ThomasW on May 23, 2016 6:40:15 GMT -7
Nothing wrong with using a spliter
A second amp isn't necessary a EP 2500 will easily drive 4 of the drivers.
No problem wiring a pair of 2 ohm drivers in series. The thing to avoid is wiring 4 drivers in series, that makes for a weird load in the amp.
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