my new 604 cabinets I'm building.

GM · October 22nd, 2011, 10:41 AM

Originally Posted by cradeldorf

yep I like the Onken alignment. It's a very open airy the people are standing right in my living room talking type of sound.

Well, it's not an Onken alignment, just looks like one at a glance. Based on your remarks, you would find a true Onken or Jensen Ultraflex alignment way too 'punchy'/'boomy'.

Yours is ~aperiodic, i.e. is somewhat resistively loaded due to having very high aspect ratio slot vents. You can get the same result with a regular reflex by stretching cloth of the right porosity over it ['click' test]. Yours are also next to cab wall boundaries, so are acoustically fairly long vents which combined results in a slower roll-off [better transient response] to a lower Fb than the smaller reflex vent. Pushing them up close to the wall further lowers effective vent length, so my SWAG is that yours are effectively an EBS alignment.

Bottom line, a very good venting choice when speakers are located near/at a wall or corner, though sealed or very low tuned [< 20 Hz] EBS alignments tend to be best overall for corners.

GM

**cradeldorf** · October 22nd, 2011, 06:20 PM

Thank's for the clarity Greg, I tried something different this morning...it was a total fail so I put it back the way it was and it sounds re markedly awesome again. I can't explain it all I can do is comment on it, Loving them right now. They sound best when I keep them about 8 inches off the side wall and about 4 -6 off the back wall.

GM · October 22nd, 2011, 07:47 PM

You're welcome! What did you try, etc.?

GM

**cradeldorf** · October 22nd, 2011, 11:00 PM

This. It was horrible.

I was shooting for just a little more openness sounding and maybe a little more bass. It was a little more open but about as far away from flat as you could get. you could hardly make out what people were saying and the lows were crazy loud.

**Panomaniac** · October 23rd, 2011, 12:59 AM

That good and funky! Thanks for sharing.

**voice of the theater** · October 23rd, 2011, 10:50 AM

OK, never seen anything like that before. You're obviously leaving no stone unturned in your search for the ideal tuning/porting--got to give you credit for that!

GM · October 23rd, 2011, 03:07 PM

Originally Posted by cradeldorf

This. It was horrible.

A variation on G.A. Briggs's ~aperiodic vent. He used many parallel saw cuts. Wider ones need to be covered with an empirically found damping material. As is, it tuned your cab somewhat higher.

One inexpensive variant to try would be a rear cover made of braced pegboard.

GM

**cradeldorf** · October 23rd, 2011, 05:42 PM

Originally Posted by GM

A variation on G.A. Briggs's ~aperiodic vent. He used many parallel saw cuts. Wider ones need to be covered with an empirically found damping material. As is, it tuned your cab somewhat higher.

One inexpensive variant to try would be a rear cover made of braced pegboard.

GM

Funny you should mention that because that's exactly what I was picturing because when I was a we little lad we used to have a stereo console and the back panel had a bunch of about 3/8 holes in it right where the speaker backs would be. That's actually what I had in mind when I did the slot thing, by making more smaller ports would give me a better more level sound. Now I know (thank's to you) that I should have at least stuffed some polyfill between the slots or something like that and not just leave them wide open. Plus the backsides of all those boards had no insulation or anything on them so probably had a lot of reflections going on inside.