Raising the While Flag on 604 Project

**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, 06:05 PM

Originally Posted by Panomaniac

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

Yeah, you guys are no help! It's obvious how dedictated/commited you guys are to this stuff. Not a single response to my question asking for guidance selling them. All you've done is get me excited again.

OK, darn it, I'm back on board....But, with one caveat, I really need to get these things right...

I'm wide open to recommendations...I sold my amp, so all I have now is a pair of gorgeous speakers, and a 20 year old CD player...

Let's do it!

**oface1** · February 18th, 2010, 06:08 PM

I second Todd's advice about getting them outside & setup stock with the GPA XO's. There you remove a huge factor in this.... the room.

-chris

**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, 06:23 PM

Originally Posted by Panomaniac

If you really want to tweak, you should get a Behringer DCX2496 and an extra amp.

So, does this device require 2 amplifiers?

**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!

**Panomaniac** · February 18th, 2010, 10:01 PM

Originally Posted by Seadweller

So, does this device require 2 amplifiers?

Yes, with an active crossover you will need 4 channels of amplification for your speakers.
The amp to run the horns does not need much power, a watt or 2 will do, but more is of course OK.

I would suggest that you decide what type of amp you want to go with for the final system. Tube or solid state. It will make a difference to the tuning of the crossover. The amp used to run the horns in active mode will make less difference, at least for tonal balance. Neither of these need to be of superb quality right now, if you just want to tinker. A 5.1 channel home theater receiver with analog inputs would do the job if you want to go solid state.

But first thing to do is what Todd and others suggest. Take them outside. See what happens to the tonal balance. If you can, arrange it so that the crossovers are easy to swap. You'll want to listen to both. Start with the horns all the way down, then bring them in slowly.

And you're right, we aren't helpful at all in getting them sold.