1204B Cabinet Mod for Home Use

[des2105]

Greetings,

I have a set of 1204B's that I would like to modify for home use. This will involve changing the cabinet somewhat to make it more aesthetically appealing and perhaps take up less room in the process.

I have in mind a size that would more closely approximate a set of Vals I curretnly have. I could mount the 511 horn externally on top of the finished cabinet so as to provide the most cubic volume in the reduceed cabinet. I am also thinking that the reduced size might eliminate some of the mid-bass heaviness as well. There is none in the Vals.

Does this sound acoustically possible or will I end up with a mess. I was hoping to use the material from the current 1204B cabinets (M1's?).

Has anyone heard of a successful modification of these speakers? Any suggestions would be most appreciated. Thank you.

[GM]

Greets!

Sure, just retune the vents as required. Which speakers and what type of mods are you referring to?

GM

[des2105]

Thanks for the reply. The speakers are 423 woofers with 511 horns. The only modification is to the size of the cabinet. At present the porting consists of 4 holes in the woofer baffle - each hole being approximately 2 - 2.5" in diameter.

Regarding retuning of the ports, does one retune by ear or can interpolation work? By that I mean if the cabinet is being reduced by say 30% should the ports be similarly reduced by 30% and achieve the same results?

Thanks again.

[GM]

Greets!

Oops! I was really tired when I posted last night and went to the website linked in the word 'speakers', so thought you wanted to mod a different brand/model speaker also.

Anyway, if it were so easy! You can tune by ear if you want since obviously you know what sounds good to you in your app. MI cabs are tuned high to get that midbass 'thump', so for a 'Hi-Fi' flatter in-room response you'll want to tune it lower, which means making the vents longer. That said, they may get too long since reducing the cab's net volume (Vb) will increase their length, as does using multiple vents, so I recommend blocking off one of them as a first approximation, then another if it still sounds too midbass heavy. Or If you can get the net Vb close to what the Vals have, then just copy its venting as a first (final?) approximation since you find their tuning pleasing.

GM

[des2105]

Thank you. I will try approximating the Vals and go from there. I find them to be considerably more flat than the current 1204's. As you observed, two different systems designed for two different applications.