My first Altecs - 604-8H

**Toph** · October 30th, 2014, 11:22 AM

Would this be the appropriate L-Pad to replace the broken one?

Speaker L-Pad Attenuator 100W Mono 3/8" Shaft 8 Ohm

Will there be sonic differences from the others? If so, should I replace them all instead of just the 1?

**Toph** · November 3rd, 2014, 12:31 PM

Well! they've been playing music for a few days now, and I can definitely say I am loving them.

The duplex design is presenting imaging that I do not hear in my JBLs - there was a period of 30 minutes last week where I sat with my eyes closed while listening to Spirit of Eden by Talk Talk. These speakers have some magic that my JBLs lack.

Two things I am noticing that I'd like to try to work out:

The midrange is a bit overpowering and the detail of the highs seems to be lacking. I've been dialing in the crossovers and trying to hone in on solving those issues, but I can't seem to get there with the stock networks.

I've read many other places that Jeff Markwart's 604-8H crossover solves both these issues.

I'd like to explore that.

I would love to pay someone to build the crossover for me - but if thats not possible...

I was wondering if anyone has a step by step guide? a parts list? I'm looking for more than just the schematic, because I do not know how to read the schematic.

**juniper** · November 3rd, 2014, 01:27 PM

Glad you are hearing the 604 magic!!! with mine its all about the recording and whats up stream. I would look into replacing the caps, and I don't know if it applies, but the M19 has a very similar crossover design and there are issues with the lugs needing to be ground. Hopefully someone can confirm.

**Alien_Shore** · November 7th, 2014, 06:15 PM

Honestly, the best way for you is most likely using an active electronic crossover.
Take a look at something like this for low budget: Rolls SX45
Or for more functionality: Behringer CX3400

**magnarc** · November 7th, 2014, 10:54 PM

I'd agree. Leave the original XOs as is for resale purposes, and get an active XO. Rane make a nice one too, AC22S.

**VolvoHeretic** · November 7th, 2014, 11:10 PM

I concur. I just recently bought a Beringer CX2310 Super Pro crossover w/ sub output for $80 at Parts Express on sale and had a Yamaha HTR-7860 A/V receiver w/ 95wpc @ .08 thd @ 20 to 20K hz fall into my lap for $75 and use the front channels for my woofers and the rear channels for the horns. Love it, except that it cost $40 for the XLR to RCA adapters.

No matter what, your Altecs should sound better in your living room than any concert you have ever attended.

I used to borrow (steal) my dad's car, saying that I had to drive my fellow stage band classmates to an out of town concert, then skip school and drive 550 miles to Minneapolis for the best concerts ever in the '70's, and then drive back before he needed it in the morning and noticed that I was gone all night. He never did ever mentioned that his car smelled like a ton of pot was smoked in it...

My morphodite Altecs w/ two box-o-10" Alpine car subs and two lonely Radio Shack piezo super tweeters sound better than any of those or any other concerts I have had the pleasure to attend.