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Post by Darren on Jul 20, 2006 12:54:06 GMT -7
Even with the drivers in 8ohm stereo you should have more than enough power to kick those IB15's into gear. Something is strange. Sumthin ain't right. With 225 watts per driver with the test drivers I had I was hitting 112db easy. I haven't measured the output yet with the RL-P 15's but will so so soon.
I suspect the room plays into the issue but you should be able to EQ for that somewhat if you are reasonably close to the IB.
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Post by chrisbee on Jul 20, 2006 12:59:51 GMT -7
Thanks Thomas.
I know of the middle frequency house curve method from the Shack.
I'll play with the BFD and REW again tomorrow to see how much the bridged amp helps and let you know how I get on.
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Post by chrisbee on Jul 20, 2006 13:15:47 GMT -7
Don't underestimate the IB's perfomace already Darren.
I can get over 110db at the listening posiition and the response curve is tilted nicely upwards and smooth.
It's just that to get there I need the speakers running over 80dB on ordinary dialogue. I'd just prefer to be able to run the IB hotter for more LF physical effects on action films.
At present I have everything set at maximum which gives me no flexibility at all. The SVS can easily beat the IB when it comes to vibrating the house and we have become used to this over the last couple of years.
I slid the microswitches over on the high pass filters on the EP2500 today to confirm they were set correctly. They were.
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Post by Darren on Jul 20, 2006 13:48:02 GMT -7
Ah, ok...yeah... now we are back to the bridging 4ohms mono which should give you the headroom you need to bring the bass up to the mains.
Can you just set the mains level lower with your AV receiver? That's how I balanced mine.
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ken
Full Member
Posts: 187
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Post by ken on Jul 20, 2006 16:36:12 GMT -7
With everthing set at max gain you should be clipping a lot.........and you not, so that means your input signal needs boosting......then you'll get the performance your after( without clipping of course ) Cheers ken
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Post by ThomasW on Jul 20, 2006 23:10:09 GMT -7
Chris,
Are those plots using the same EQ? Or is there one preset for the IB and another for the SVS?
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Post by chrisbee on Jul 21, 2006 10:47:10 GMT -7
Sorry Thomas I've been out all day and couldn't respond earlier. The SVS is raw. No Eq at all = REW straight off the soundcard calibrated @ 80dB nominal on pink noise. The IB is +16dB @ 20 Hz then higher frequ. negative filters to bring the response back down to the target curve. The bridged mode seems louder and the bass slightly better defined and more powerul despite using 12 0'clock settings for the input gain controls on the EP2500 instead of max. No chance to try a film yet as we've just got home. I'm listening to organ music (as usual) and could easily roll back the gain to flat on the CX2310 and still have truly excellent and well defined deep bass. This actually sounds like real progress!
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Post by chrisbee on Jul 21, 2006 10:52:09 GMT -7
Ah, ok...yeah... now we are back to the bridging 4ohms mono which should give you the headroom you need to bring the bass up to the mains. Can you just set the mains level lower with your AV receiver? That's how I balanced mine. Hi Darren I was +6dB on the IB and -6dB on the speakers on the active crossover. Until I tried bridged mode I had no way of making the IB any hotter as the EP2500 was already at max on the twin controls too.
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Post by ThomasW on Jul 21, 2006 11:04:39 GMT -7
The bridged mode seems louder and the bass slightly better defined and more powerul despite using 12 0'clock settings for the input gain controls on the EP2500 instead of max. What's the reason for the controls at 12:00? Simply to protect the drivers? I think you're safe with pretty high amp levels to the AE-IB15"s. There was a dialog a while back discussing how very stiff the spider was in those drivers. So they should handle a ton of power. To increase the apparent output of the sub, you can alway back off the main speakers output level. Depending on what speaker system is running in my family room (it's the system I use for R&D when I'm making DIY mains) occasionally there's a huge disparity between the crossover level between the IB and the mains. The output disparity means nothing as long as there's enough amplifier power to do the job.
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Post by jagman on Jul 21, 2006 11:45:57 GMT -7
Congrats on figuring out your problem... it's always nice when it doesn't cost more money!!!
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Post by chrisbee on Jul 21, 2006 11:50:44 GMT -7
If I blow my AE drivers there are no more available to replace them.
I am approaching the bridged amp arrangement with some care.
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Post by ThomasW on Jul 21, 2006 13:16:46 GMT -7
If I blow my AE drivers there are no more available to replace them. I am approaching the bridged amp arrangement with some care. I understand. You've got 14mm Xmax with an almost bottomless design, so you should be able to move a significant amount of air without stressing the drivers..
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Post by chrisbee on Jul 21, 2006 13:22:17 GMT -7
An update:! Having listened quietly for an hour I turned up the volume. I have just discovered that I don't need more than 12 o'clock on the EP2500 now with the crossover set flat on the IB channel. Or the bass becomes so completely overpowering it is really unpleasant being in the room with the music, Synthesiser bass is now enough to cause serious discomfort! The strange thing is that the cones are still hardly moving! Less than before if anything. Even at 12 o'clock on the EP2500 controls it is really far too much bass for music! I have now flattened the gain on the crossover for both IB and speakers. 12dB extra gain on the IB over the speakers is now no more. The music now sounds simply incredible! So, it should be about right for films now. If I can survive the ordeal!
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Post by Darren on Jul 21, 2006 13:46:05 GMT -7
Sweet! Glad you got that worked out You may find that you like a different curve for music. I use the same curve for HT and Radio but have a curve with less taming for CD audio and DD audio.
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Post by ThomasW on Jul 21, 2006 15:53:20 GMT -7
Okay now you're getting close..... Time to turn it up to "11"...... Louder, louder, louder, louder........ ;D
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Post by jman on Jul 21, 2006 18:16:37 GMT -7
chrisbee- An interesting account earlier in the thread. I sold my dual SVS cylinders due to lack of output/SQ when pushed hard and that was in a sealed 10x12' room. The pair of SVS's could hit peaks above 110db but it was a rather sloppy, loose sound. When my IB is finished I'll write up a full comparison.
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Post by chrisbee on Jul 21, 2006 22:17:21 GMT -7
Thanks for all the advice and encouragement, gentlemen. The improvement in performance from the IB is dramatic! Really night and day at higher volume levels. No time to try many favourites with music or film yet but it sounds even tighter and cleaner than before on the stuff I have listened to. If I turn it up any higher, Thomas, they'll need two buckets and shovel to clean up the mess! As soon as the Head Gardener toddles off to play with her plants I shall be having a blast. I'd better start with that LOTR Prologue. If I survive that I can go on from there. Thanks again
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Post by chrisbee on Jul 21, 2006 22:31:56 GMT -7
chrisbee- An interesting account earlier in the thread. I sold my dual SVS cylinders due to lack of output/SQ when pushed hard and that was in a sealed 10x12' room. The pair of SVS's could hit peaks above 110db but it was a rather sloppy, loose sound. When my IB is finished I'll write up a full comparison. Hi jman Too late for you now but you should have tried the SVS subs well out into the room. I found the sound quality was seriously improved with some air around my single one. I could still hit around 108dB (uncorrected C-slow) without it ever sounding strained. I used 12 o' clock as the standard gain setting for films and it seemed unburstable with masses of LF vibration throughout the house. On music it really tightened the bass having it well away from the corner. I might even have sold mine if I had been forced to use it in the corner. It was just too soft and totally overpowering there with only the tiniest amount of gain on the SVS amp. Out in the room it was dry and powerful and the gain control became nicely flexible. I used mine with high level connections with 40Hz mains running full range for a couple of years before I built the IB.
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Post by eeyore on Jul 22, 2006 5:42:28 GMT -7
It's great that this has been worked out.
If I may ask... How does one calibrate their sub if everything is cranked up?
I have my amp up full but I had to cut back the input signal from my receiver 2db to equal the output from my mains.
Wrong?
I bought Darren's EP1500 so reinforcements are on the way.
These AE IB15's are so stiff that I figured that more power couldn't hurt.
I'm just wondering if I have been doing something wrong.
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Post by Darren on Jul 22, 2006 7:30:14 GMT -7
That sounds like a reasonable way to adjust to me. I try and have a little amp left and a little adjustment in the receiver if I can help it. That way I can make fine adjustments with the amp on different movies/music where I feel the need for more or less bass. I don't leave much but could easily live without the amp adjustment as long as I had enough signal adjustment in the receiver left.
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