Just ordered Everest DD-67000

[jpw]

The white paper I have says 5 ohms at 80hz is the impedance minimum point
in the audio range. It dips to 3.8 ohms at 40khz but this is inconsequential
with so little actual signal there. Except for the port tuning humps, most of the speakers curve is in the 6-8 ohm range so I use the 8 ohm taps on my MC-601's. The 4 ohm tap was noticeably muddy, dull and under-damped sounding.

I already do have room treatment and traps! These help best on walls or in corners but can't be used very practically on ceilings or floors, which is where my problem is. 7 foot 6 inch ceilings = 75hz resonance. EQ and or processing of some kind is used in nearly every recording made. I have no aversion to using on playback provided it is transparent. I have heard a number of digital EQ's that meet this requirement.

[Eisener Bart]

My congratulations! I am dreaming to listen Everest!

[jpw]

I let the 67's play overnight quietly to give the driver suspensions more time to limber up. I started over this morning with them determined to find "the" best spot for them. I measured each speaker individually and finally found a place I could live with that minimizes my 80hz-160hz problem. I got the
error down closer to 4db from 6db and with more deep bass to go with it.
While I can still hear this slight bass emphasis, individual notes no longer stand out from others unless played that way. I've got them toe'd to intersect just behind my head, or aimed at each shoulder if you will.
This gives good focus and the right balance through the mid's and highs.


Below is a copy and paste from a post I made on the Lansing Heritage forum
concerning the Everest's at Harman's exhibition booth at the Hard Rock Cafe for CES 2014.

If you have only heard Everest's at a trade show, I can understand how somebody could think they aren't as great as advertised. Harman's CES area at the Hard Rock was nothing more than a huge, I mean huge, empty space finished off with all of the fixtures and equipment you would expect at a trade show. The Everest's were in a space sectioned off by some very flimsy make shift walls, incapable of containing any bass and only allowing a muffling of the rest of the sound happening outside. They were set up fairly close together, about 7-8 feet apart, and listened to at only 10 feet away or so. Given all of the disadvantages I thought they sounded real good. Deep bass was down at bit as expected and there was some small amount of upper bass coloration, common at trade shows. The DD-66000 is a very good speaker and right now is extremely competitive at it's street price, if not a best buy. I've only been listening a few hours to mine, but the 67 improves upon the 66 while maintaining the basic essence. It's just more linear with a better octave to octave balance and it seems to have less energy storage with a quicker bass attack and decay.

[Dave_72]

Originally Posted by jpw

The white paper I have says 5 ohms at 80hz is the impedance minimum point
in the audio range. It dips to 3.8 ohms at 40khz but this is inconsequential
with so little actual signal there. Except for the port tuning humps, most of the speakers curve is in the 6-8 ohm range so I use the 8 ohm taps on my MC-601's. The 4 ohm tap was noticeably muddy, dull and under-damped sounding.

I already do have room treatment and traps! These help best on walls or in corners but can't be used very practically on ceilings or floors, which is where my problem is. 7 foot 6 inch ceilings = 75hz resonance. EQ and or processing of some kind is used in nearly every recording made. I have no aversion to using on playback provided it is transparent. I have heard a number of digital EQ's that meet this requirement.

Ok, thanks for the info. I wonder what my S4700s dip down to. Hmm...

Sounds good about the room treatment. I'm not adverse to using EQ too.

[jpw]

With such a similar design topology as K2 or Everest, I would expect 5 ohms or
the very high 4 ohm range to be the impedance minima, at least in the 20-20khz region. The dual Everest woofers are effectively 16 ohm woofers wired in parallel to give 8 ohms.

Perhaps the dual voice coil woofer design will prove me wrong but few JBL designs have ever dropped below this point. I will try to find out from JBL directly. I could not find an impedance graph online.

[jpw]

Dave 72,
I went back through my emails from Greg Timbers (head JBL engineer)
and found your info. 4.5 ohms at 100hz is your answer. The S4700 is rated
nominally a 6 ohms. Any modern high quality high power amplifier should
drive them fine, electrically speaking.

Did you know that the S4700 woofer is the woofer used in JBL's new M2
studio monitor?

John

[Dave_72]

Originally Posted by jpw

Dave 72,
I went back through my emails from Greg Timbers (head JBL engineer)
and found your info. 4.5 ohms at 100hz is your answer. The S4700 is rated
nominally a 6 ohms. Any modern high quality high power amplifier should
drive them fine, electrically speaking.

Did you know that the S4700 woofer is the woofer used in JBL's new M2
studio monitor?

John

Thanks I appreciate that! Well, I'm currently driving them with a Bryston 4BSST (not SST2) and I haven't had any issues. However, I'm gonna move to a better sounding (imo) but lower powered Accuphase amp. The Accuphase amp doubles down all the way to 1 Ohm.

No, I did not know that. That's pretty cool.