[kilohertz]

I have had a nice set of Audio Marketing Big Reds with Altec 604-16LN drivers for about 35 years. I have them in my living room and am getting setup to tune the crossover levels with REW and thought about re-tuning the cabinets for flatter response. The last time I had them on REW I noticed a hump around 180Hz ( I can't find the scan print it's on an old computer)


I imagine changing the stuffing might be able to smooth it out or changing the port dimensions.


Anyone played with Big Reds?


cheers

[FullRangeMan]

hump around 80Hz
This is great for bass, you dont like bass freq?
Avoid change the port dimensions.

1) Round off all corners with 30/40mm triangular wooden profile.
2) Paint entire interior with matte black, thick paint.
3) For acoustic treatment and increase bass use car wood brown blanket 15mm at your personal taste, try and error.

[kilohertz]

Ya shoot that was a typo, should have said 180Hz. It also could be room influence which there is not much I can do about.

What is meant by "round off all corners with 40mm triangular wooden profile"?

Interior is already painted black and there is about 3/4" firm fibreglass attached to all surfaces. Are you suggesting adding material or replacing with your suggestion?

One thing I noticed when I was remounting the xovers is that the back panel has some resonance. I'll start with some extra bracing on the back.

Thanks

[FullRangeMan]

Interior is already painted black and there is about 3/4" firm fibreglass attached to all surfaces. Are you suggesting adding material or replacing with your suggestion?
Dont mess with this fiberglass, its toxic to the lungs and skin.
If you want more bass add some car wood 15/20mm blanket on the enclosure back.
What is meant by "round off all corners with 40mm triangular wooden profile"?

[genjamon]

Uh oh, do you mean there’s asbestos in the fiberglass?!?!?

[FullRangeMan]

The solvents and resins used in manufacturing process are extremely toxic.
Those who work with FG must wear mask, gloves and special clothing because the particles released can cause irritation to the skin, eyes, and respiratory system, so in a short time I worked with car audio I discovered that engine hood blanket is much better and cheaper, creates more bass, last longer and is non-toxic.