Vintage, Bipole, Resonant Box

[avincenty]

I had purchased a set of Blaupunkt console speakers, 4 6x9 woofer/mids and 6 tweeters. It appears they came out of a Newyorker console.

So what to do with them? I was researching some of these vintage paper drivers and found some sites talking about resonant boxes for Saba drivers. I figured it would be relatively inexpensive to try them out. I quickly built a box 36Hx16Wx8 deep using 1/4 inch luan plywood (very inexpensive $10 a 4x8 sheet) and some 2x2 legs. To speed things up I used glue and brad nails.

Since I had so many drivers, I decided to make it a bipole. Then added the remaining two tweeters, one on top and one on the side (this is probably a no no but what the heck). I put a phase switches and a LPAD for the top and side tweeters as I had no ideal how they affect the sound. Both in phase with the front appears to have the most focus.

I am driving them with a 7591A PP tube amp and these things sound quite wonderful. The box does resonate as I can feel by touch. Bass is quite present.

I am not sure if I should get rid of either the top or side tweeters. I would need to play with the connections and remove them from the circuit one by one. The room is full of music compared to my BR box with audio nirvana Super 12 CF which has laser focus and appear to come from one center spot.

Pleasantly suprised for sure.

[phivates]

Now that's diy baby. Go with what you got.

[AllenB]

+1, great way to get into DIY. Especially like the cabinets. I once had a speaker with a ply cabinet I was enjoying the sound of but then I braced the cab with hardwood and it killed the sound. It was so lacking that I soon began thinking of what to build next. (of course this is just to taste with some speakers)

I think you'll find that bipole has benefits in the woofer area. The lager paper tweeter is interesting and I'd go for the single tweeter at the front. That's just my preference.

[avincenty]

Thanks. The enclosures are kind of disposable. If they end up being "keepers" then I may either build new nicer ones with glue only or give it a vintage look by replacing the top with a nice solid wood piece and maybe wrapping it in a vintage speaker cloth.

I used all 4 tweeters per cabinet as the Newyorker console used two per mid/woofer. In the original had the two tweeters in series and a 4uf cap. For my project I put all 4 in series with a 2uf cap.

I don't have any experience using multiple tweeters. I have searched for side firing tweeters but don't find much.

I will try turning off the side tweeter and putting a 3uf cap.