Altec 604-8g's how to improve?

[gearfreak]

- what do you like about them
- what do you want to improve?
- would you go to a bigger cabinet?

Seems bass response is on the list -

The 612C is spec'd as 6.8 ft3, I don't see a cabinet tuning listed.

You might first get an idea of what you are dealing with,
- by measuring the impedance response of the LF section.
- by measuring the 'free air' parameter impedance response of the 604 itself.
A bass reflex should exhibit 2 peaks in the LF. So comparing/contrasting the two, you get a picture of what the cab is doing to the driver response as a matter of now being a system.

Then you can block off the port and see (while hearing) what difference that makes.

Then infer whether enlarging (or otherwise tweaking) the port is what you might want to do, or might want not to do.

I have 604's in 3154's (spec'd: 6 ft3) and have a bit of a hole from 55-80hz, maybe ranging a bit higher, ...to sort out.

[Terp]

- what do you like about them
- what do you want to improve?
- would you go to a bigger cabinet?

Seems bass response is on the list -

The 612C is spec'd as 6.8 ft3, I don't see a cabinet tuning listed.

You might first get an idea of what you are dealing with,
- by measuring the impedance response of the LF section.
- by measuring the 'free air' parameter impedance response of the 604 itself.
A bass reflex should exhibit 2 peaks in the LF. So comparing/contrasting the two, you get a picture of what the cab is doing to the driver response as a matter of now being a system.

Then you can block off the port and see (while hearing) what difference that makes.

Then infer whether enlarging (or otherwise tweaking) the port is what you might want to do, or might want not to do.

I have 604's in 3154's (spec'd: 6 ft3) and have a bit of a hole from 55-80hz, maybe ranging a bit higher, ...to sort out.

I like the midrange and "live" soundstage.
I would like more bass and a more cohesive sound (compared to my other speakers, PSB Imagine T3's)
I also would like a nicer looking cabinet, taller (ear level) and possibly larger CU ft.

I dont know how to do those measurments, ie LF frequency response etc.

Thanks

[bowtie427ss]

9 ft3 minimum ~ 40hz tuning, with a broad/wide baffle to control step response

Markwart phase corrected network, or just go active and don't look back.

Where's 604man with those 20+ ft3 boxes?

[604man]

9 ft3 minimum ~ 40hz tuning, with a broad/wide baffle to control step response

Markwart phase corrected network, or just go active and don't look back.

Where's 604man with those 20+ ft3 boxes?

HI, Yes just search "604-8g big cabinets big sound".

the cabs work good I gave the dimensions in the post .


604-8G.jpg

[Phil-G]

HI, Yes just search "604-8g big cabinets big sound".

the cabs work good I gave the dimensions in the post .


604-8G.jpg

unfortunately photoFuckit has your pictures hostage.
http://www.hostboard.com/forums/f700...nets+big+sound

[rogerh113]

I built some 9 cu ft cabinets for my 604-8G, including Markwart crossovers. The bass goes low, and is tight and clean. I could not be happier. There is a thread on this board with all of the questions and responses from members here. Might provide some perspective on the larger cabinet option. With a bit of care, they might also meet the WAF hurdle.....

[Earl K]

unfortunately photoFuckit has your pictures hostage.
http://www.hostboard.com/forums/f700...nets+big+sound

I'll assume that means you can't see 604mans pic.

FYI, I can see the pic because I use an extension for my ( Chrome ) browser called"Photobucket Embedded Image Fix"

This has worked well for me for quite some time ( at least a year now, if not more ).

[Phil-G]

I'll assume that means you can't see 604mans pic.

FYI, I can see the pic because I use an extension for my ( Chrome ) browser called"Photobucket Embedded Image Fix"

This has worked well for me for quite some time ( at least a year now, if not more ).

well there they are howabout that.

[gearfreak]

I like the midrange and "live" soundstage.
I would like more bass and a more cohesive sound
...
I dont know how to do those measurments, ie LF frequency response etc.

Thanks

a) to avoid cabinetry work you could first try a "current-drive" / "transconductance" / "constant current" amp instead of a 'voltage drive' amp. Your work would be to determine what is one, and then finding one to build or buy. (we presume the latter).
For that however, you will then need to build a current-drive crossover.
I have a simple working example based on the info presented in: PassDiy

It would seem that in practice there can be a grey area, or transitional zone wherein voltage driven becomes (closer to?) current driven (perhaps a matter of 'added series resistance', perhaps not).
Others can comment on the veracity of those terms used. I am discerning the differences myself at the moment.


b) In olden days, you would plot this manually using a certain technique.
Nowadays Parts Express sells the 'DATS' unit for your computer. There may be others.
Pretty much: You hook up the driver, and press a button.
An example of the (free air) impedance plot I created for my 515's can be seen at: Altec / GPA measurements: 515 - diyAudio



ps. in other threads when 'Z' is discussed, it is nominally referring to 'impedance'

[604man]

I like the midrange and "live" soundstage.
I would like more bass and a more cohesive sound (compared to my other speakers, PSB Imagine T3's)
I also would like a nicer looking cabinet, taller (ear level) and possibly larger CU ft.

I dont know how to do those measurments, ie LF frequency response etc.

Thanks

What do you mean by a more cohesive sound ???