Raising the While Flag on 604 Project

**Panomaniac** · February 18th, 2010, 05:29 PM

Hey, maybe we've got you back on the horse! :2thumbsup:

If you really want to tweak, you should get a Behringer DCX2496 and an extra amp. You may already have the amp. You can always sell the DCX2496 after if you don't want to keep it.

I got a pretty nice sounding rig going with the 604-8K and the DCX crossover. No lack of bass, not shouty. Good imaging. Those drivers should be close enough to your 604-8H to be no problem. My crossover points were 1160Hz on the woofer, 1530Hz on the horn. 3rd order butterworth. Some shelving EQ on the woofer and the horn. 28mm delay on the woofer.

With the DCX2496 you can tweak to your heart's content and we could even help. Once you get what you like, a passive crossover could be built. I feel for your crossover guy. Doing it long distance like that is super hard.

**Todd W. White** · February 18th, 2010, 06:02 PM

The 604K's, almost without exception, have the wrong magnet on them - after EV bought Altec, they forced them to consolidate on some standard magnets EV was already using, and they made Altec use the DH-1A HF driver magnet, if memory serves, for the 604 and the 515.

The result in the 604-8K was the midband got too much energy. It wasn't that the bass was suffering - it was still there, just like always - but the midband was getting too much magnetic energy. Jerry Hubbard figured this out and fixed it - the GPA 604's don't have this problem.

I believe you're using GPA-built 604's, so this isn't an issue, but I thought I would mention it anyway.

Here's a really stupid question - have you tried taking them outside, weather permitting, and listening to them using the GPA crossovers, no eq, and a live recording? You might find they sound completely different, maybe actually really good!

**Seadweller** · February 18th, 2010, 06:14 PM

Originally Posted by Todd W. White

Here's a really stupid question - have you tried taking them outside, weather permitting, and listening to them using the GPA crossovers, no eq, and a live recording?

Hi Todd,

Yes, GPA 604's is what I'm using...Actually, I haven't thought of taking them outside...The neighbors might think I'm nuts, but hey, who cares?

I've got to find an amplifier now...

**oface1** · February 18th, 2010, 06:19 PM

You located anywhere near central SC? I would gladly help out if so......

-chris

**Seadweller** · February 18th, 2010, 06:24 PM

Originally Posted by oface1

You located anywhere near central SC? I would gladly help out if so......

-chris

Thanks for the offer Chris...I'm actually in the Tampa Bay area...

**Altec Best** · February 18th, 2010, 08:38 PM

Welcome Back !!! You just put a smile on my face for a week at least

Do you have other set of drivers,stock Altec Xo's that you can swap out to see if you have the same result say a Altec 604-8G, or Altec Lansing 604-8H or another 604 if not can you borrow one with original Xo's if they sound the same then it would be your room acoustics or enclosure would it not.As others have said the room does look to be bare alot of hard flat surfaces.Moving them out to test outside or in another room is a good idea.Sending Xo's back and forth 1000 miles a half dozen times definately needs to end

Your boxes definately have plenty of volume did you post the dims of the port size.I can imagine the look on your face when you eventually get to that sweet spot. (

) Regards ~ John

**rontec** · February 18th, 2010, 09:16 PM

I don't know anything about the Altec 604. Can it be connected to just the LF side of the speaker? And if so, would that help to determine if the 604 is working properly?
As Altec Best suggested trying some other drivers in those beautiful cabs might give you some clues? When you get it right you'll be more than satisfied you hung in there!

**SD-50** · February 18th, 2010, 10:39 PM

Originally Posted by Todd W. White

The 604K's, almost without exception, have the wrong magnet on them - after EV bought Altec, they forced them to consolidate on some standard magnets EV was already using, and they made Altec use the DH-1A HF driver magnet, if memory serves, for the 604 and the 515.

The result in the 604-8K was the midband got too much energy. It wasn't that the bass was suffering - it was still there, just like always - but the midband was getting too much magnetic energy. Jerry Hubbard figured this out and fixed it - the GPA 604's don't have this problem.

I have a pair of 604-8ks waiting for cabs and this is the first I've heard of this problem. Is there a solution to correcting the midband by replacing, or modifying the stock XO?
Cheers

**Tom Brennan** · February 19th, 2010, 03:16 AM

Maybe the speakers just aren't for you, especially if you're fighting their basic nature so to speak.

**vuki** · February 19th, 2010, 03:28 AM

In my expirience problem with the bass is in the lowpass part of the crossover. Due to the rising response of the 604's bass/midrange driver, low pass crossover should be done so that it compensates it otherwise 604 speaker would have "no bass" and "shouty" sound.
Seadweller: try it with the crossover I posted