604C's in a small room....

**Twodawgz** · August 10th, 2008, 02:37 PM

While space would certainly be a consideration in a small room, personally, I would stay away from wall mounting the 604s because I believe the bass frequencies are favorably enhanced when you have a floor standing model. Of course, porting of the speaker enclosure has a lot to do with that as well. Because of limited space you may, however, be forced to wall mount your speakers.

**speakerdave** · August 10th, 2008, 11:39 PM

Originally posted by ejfud:
. . . . my room is very small. Roughly 9' x 12'. The speakers will be on the 9' wall . . . .

<font size="2" face="Verdana, Helvetica, sans-serif">In that size room the coaxial format is ideal for its integrated sound at close-up distances. I would not think a large enclosure would be worthwhile, since frequencies below 40-45 Hz may not develop in that room. That is low enough for most music. A 612-sized cabinet would probably be all you need.

David

<font color="#FFFFFF" size="1">[ August 11, 2008 01:30 AM: Message edited by: speakerdave ]</font>

**selmerdave** · August 11th, 2008, 04:41 AM

Really? I'll say this, I got an enormous improvement in low bass when I went from rather small 4.5 cu. ft. (internal) cabinets to my present 20 cu. ft. ones, in my small room. I suspect bass would be even better in a larger room but based on my experience I see no reason to advise smaller cabinets for a smaller room.

Dave

**Fran604g** · August 11th, 2008, 07:04 PM

Originally posted by ejfud:
Well you are giving me hope, thanks.

620 cabs would be doable I think. Do you have them on stands? I'll have to look for the plans for these.

Would the Stonehenge III cab be a good option?

<font size="2" face="Verdana, Helvetica, sans-serif">Sorry about taking so long to get back to you, I was gone all weekend.

1)No, I don't have mine on stands, but I would like to raise them maybe another foot off the floor.

2)I don't know...

The 620 cab plans are here at the Lansing Heritage site:

http://www.lansingheritage.org/images/altec/plans/1970's-lf-plans/enclosures07.jpg

The plans shown were the cabinets that were used for the 604-8K (620B) speakers, and the only difference I've found in the cabinet for the 8G (620A) was the size of the cutout for the crossover (different shape and location) and the location for the port. They're both 9^3 feet cabinets. The 15" B.C. and 14-1/8" opening for the speaker appear to be the same for both speakers.

If you do a little searching, you should be able to come up with the drawing for the 620A cabinet, but if you're not using stock crossovers, you won't want the cutout for it anyway.

Have you checked out Billforts cabinets? He built some beautiful corner cabs. They can be found here:

http://www.wardsweb.org/Billfort/

Good luck.

**ejfud** · August 12th, 2008, 12:36 AM

Man that 620 is a big cabinet! Really bigger than I was looking for. I must have been thinking of the 612.

I'm beginning to think these may be real good in this room with a smaller cabinet tuned higher and letting the corner placement of the cabinets help with the bass.

**ejfud** · September 4th, 2008, 01:45 AM

The drivers are on there way to Great Plains for a rebuild. Thanks for all you direction so far.

Now to figure out what cabinets to build.....

Gary

**Tranquil** · March 24th, 2009, 11:58 PM

So Gary what cabinets did you Build? I'm about to build cabs for my 604-8H the room is 10'x 15' speakers on the 10' wall. I like the height of the Stonehenge V and if I build 612 cabs and have to place them on stands I might as well build the SH V. Just reading along and curious as to how you made out with your project.

Tony

**whitebroncoii** · March 25th, 2009, 11:17 AM

The 604 was originally designed as a near-field recording studio monitor. Years ago an Altec engineer told me the 604 has a 10' - 12' "focus". AcoustaCadd measurements seem to verify this.

**ejfud** · March 27th, 2009, 02:55 PM

I just picked up a nice pair of cabs that the 604C's will finally land in. They are a little over 5 cu/ft. I'll need to work out porting, any help would be appreciated, but they should look great when done.

Gary

GM · March 27th, 2009, 06:17 PM

Originally Posted by ejfud

I'm beginning to think these may be real good in this room with a smaller cabinet tuned higher and letting the corner placement of the cabinets help with the bass.

Actually, the norm for this configuration is to tune it low as you don't want the corner boosting the grossly out of phase output below box tuning no more than necessary which usually means around 27-32 Hz for all but pipe organ symphonies and movie special effects.

GM