problems with new Iconic 704-8A crossover

[dr.joe]

I've been enjoying my Altec 604-8K in old Altec 620 cabinets so much that I purchased a pair of Iconic 704-8A with the latest version of the Iconic SuperCrossover. The plan is to make a Stonehenge V clone cabinet for them.

So far, though, I find I MUCH prefer the 604-8K with stock Altec crossovers to the 704-8A with their expensive custom crossovers. With the 704-8A/SuperCrossover combo, all guitarists sound like they're using nylon strings; sax players have lined their instruments with vaseline; the bass is deep and powerful, but lacks the clarity and energy of the 604-8K. Vocals are, perhaps, better, but overall I feel I've lost a lot more than I've gained.

Given all this, I'd be grateful for any comments or suggestions from those who know both the 604-8K and the Iconic 704-8A/Supercrossover...note that these are the version 2 of the Supercrossovers which just became available in April 2008.

Is the solution to go back to the original Altec crossover design or perhaps Jeff Markwart's design?

FWIW, the folks at Iconic are mystified at my comments; they say all listeners to date have been very pleased with the version 2 SuperCrossovers.

TIA,

Joel.

[Todd W. White]

Sounds to me like there's some sort of problem in them inherent to the components - perhaps one of them is faulty from the manufacturer. It's been known to happen...

No idea how the Version 2 of the SuperCrossover sounds - I've personally tested the original design, which is offered by GPA for their 604-8H-II (though not hand assembled, Bill says it measures identically to the one offered by Iconic), against the stock 604-8K and it's stock crossover and can assure you it IS much better than the stock item.

Other than that, I don't know what to tell you...

[DNV47]

I don't want to bad mouth Iconic or any other company that uses "super" or "audiophile quality" parts in their products BUT ya know, sometimes the best on paper just doesn't sound the best to all of us.
I've been through this with expensive coupling capacitors in amps and capacitors and inductors in xovers so it's no surprise to me.
I replaced the caps in my Model 19's and there was a big improvement over the aged originals but I knew I liked that brand and type of fairly inexpensive caps in xovers beforehand.
And replacing inductors does change the DC resistance in line with the woofer for good or bad.
I think the Iconic Super Model 19 xover uses fixed resistors in place of the two pots found on the original xover BUT the fixed resisitors offer who's taste in Model 19 sonics?
I understand the idea behind it but I'd want to pick the resistor values myself.
I offer this opinion assuming there isn't a problem in your hookup,drivers or equipment.

[gortnipper]

How long have you let them break in? I have heard it takes a LOOOOOOOOOOONNNNNGGGGGGGG time - 400-500 hours.

[DNV47]

OK. Devils Advocate here but after 400 hours of listening to sonics you don't care for and having totally forgotten what the speakers did sound like,drop the original xovers back in and see which ones you really like the best.
Don't forget the breakin CD's and LP's should you go that route.
With a CD you could shut the door and let the system play on repeat for a week.

[gamalot]

The very first sentence says allot to me!

"I've been enjoying my Altec 604-8K in old Altec 620 cabinets so much"

Why fix what wasn't broke?

Gary

[LICORNE]

The best advice was given to you by Todd White.

............

[Todd W. White]

If memory serves, the crossover offered orignally by Iconic was designed by Jerry K. Hubbard, former Head of the Acoustic Research Department at Altec. This is the crossover I listened to at length, and is the one Bill at GPA sells with his 604-8H-II (the crossover for the 604-8H-III is different, so as to accommodate the UREI horn, and is still being "tweaked").

I have no information on the second version being sold by Iconic for their 704.

[RonSSS]

Dr.Joe,

You hear what you hear, and if it's wrong, it's wrong! It's simple.

The GPA or Iconic was voiced by someone who hears differently. And I bet they don't install and listen to every pair sold.

I'm not sure why the stock X-overs with the adj mid and hf controls are bashed so bad. Todd! Unless you way over power them, they do not burn out! Unless they were used in a high moisture condition, they don't go intermittant! I find the adjustment VERY useful, both on the Duplex and the M19's.

Go look at Jeff Marquarts site.

He has set them up so you only have an MF adjustment, and it will attenuate lower than the stock ones....I think that is a good thing! The MF really needs to be able to be adjusted lower......I am happiest with mine at or near mim.

I added botique caps to my duplexes....hated them. There are many to try....and I'd have spent hundreds of dollars finding what I liked.

And, forget burn in. Drives me nuts! By the time you burn in for the so called 400 hours...you will forget what you heard, unless you go back to what you liked. And if you still don't like it....you wasted 400 hours.

The burn in **** to me simply means memory loss.....

Ron

<font color="#FFFFFF" size="1">[ August 06, 2008 01:45 AM: Message edited by: RonSS ]</font>

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After reading this thread I went back to my Model 19s and rewired the stock crossover replacing the Iconic.

I had originally purchased the 19s about a year and a half ago with the Iconic crossovers installed by the seller, and had never listened to them with the stock crossovers in my home.

Up to now, there was always "something" lacking with my 19s. I've replaced the stock 902-8A compression drivers with TAD 2001s to good results, but still the speakers were lacking low level clarity and initial transient response. Drums, snares and cymbals just didn't sound right, but voices were very good. I would describe the sound as slightly dark and muted.

Going to the stock crossover has restored my faith in basic Altec engineering. Even with the stock 902 reinstalled, they had better high frequency response than with the TADs with Iconic.

With the stock crossover, small nuances and upper harmonic air is now apparent were the Iconic just omits this info. Guitar body resonances, voice inflections and a general "aliveness" are now coming out of my 19s with the stock crossover. With the Iconic, it does the Audiophile thing of making good sound, but not music. Plus the Iconic offers less clarity.

I drive my Altecs with a 8-10 watt battery powered Altmann BYOB amp. With the stock crossovers installed the 19s are doing so much more correctly now, I'm rediscovering my music collection. And with the TADs installed, I'm in heaven.

This is my experience with the Iconic crossover for Model 19s, and its probably not universally applicable. But let your ears judge for themselves.