[windupman]

Hi everyone,

Reading some posts here leads me to apologize in advance: I don't understand some of the terms used, let alone all the calculations. In fact, I haven't heard many open-baffle speakers, let alone DIY versions. However, in my semi-obsessive researching of speakers, I thought OB might be the way to go for our space. Plus, I think I can make them look good, which is a consideration.

The room is roughly 18' x 40' with 9-foot ceilings, concrete floors, some large glulam beams across the ceiling, a staircase at one end and an open door at the other. Often, we'll be as much as 20 feet from the speakers, which will be roughly 4 feet from the front and side walls and 8 feet apart (depending on how wide the baffles are.

The only parts that are already on hand are from an old Zenith console. The 12" full-range drivers are 49CZ861, which are supposedly similar to the 49CZ852 drivers, but with a closed-magnet design (I don't know what that means, BTW). Also, the console works, so the tube amp, crossovers and tweeters could possibly be used or modified.

I spent more time than I would like to admit reading the Linkwitz Lab website and the OPLUG forum to learn about the LX521. But that seemed seriously expensive and complicated. And I couldn't find anywhere to hear it.

After stumbling on the Pure Audio Project, I thought that might be a good approach: large woofers that extend up into the midrange seem like they could be effective in a big room.

A few other considerations: my budget is $1000, including amplification. I'm into it for $90 so far for the console stereo. I'll likely be streaming all audio. And I like a more neutral-sounding speaker. Dynaudio sounds good to me, as do some vintage speakers such as the JBL L150s. I don't respond as well to the mix coming from speakers like the Klipsch Fortes; they sound exaggerated on the high end to me.

With that background, can folks suggest an approach that would sound good in our space?

Everyone has been very welcoming so far. Thanks in advance for any suggestions you might have.

David

[FullRangeMan]

You could try the 49CZ861 direct no xover in a Visaton Nobox baffle and if more bass are need you could add a Alpha15A($70 each) or other similar woofer cuting at 270Hz with 4.7mH.

[windupman]

You could try the 49CZ861 direct no xover in a Visaton Nobox baffle and if more bass are need you could add a Alpha15A($70 each) or other similar woofer cuting at 270Hz with 4.7mH.

I like that idea - it's an easy way to get started. Thanks!

[FullRangeMan]

I like that idea - it's an easy way to get started. Thanks!

Disregard the xover pictured.
Avoid iron core inductors, this is a good inductor just in case you need:
https://www.madisoundspeakerstore.com/goertz-14-awg/goertz-cf4.7-14-awg-copper-foil-inductor/

This other 6.0mH inductor will cut at 210Hz, also a nice cut for a 12'' FR as the Zenith, 270 or 210Hz depends on your personal taste:
https://www.madisoundspeakerstore.com/goertz-14-awg/goertz-cf6.0-14-awg-copper-foil-inductor/

[Dmason]

I think the Visaton No-Box, and the Zenith 12" idea is a winner. The Zenith, with some miles on it is by all accounts a BIG winner. The Visaton design guarantees success. The Eminence Alpha are a well worn path to cost-effective bass. I would find a tube guru in your area to check out the Zenith amp. Likely it is a single ended EL84/6BQ5 Mullard type design, and easy for fixem up. Now you have single ended tubes to start with, powering a large calibre wideband driver employing an AlNiCo magnet. -a veritable feast of wins right there.

[windupman]

Thanks guys!

The Visaton baffle looks promising, but I think may want to build my own which could be closely based on Visaton. Quick question about that: Would it change things dramatically if I put a small top on the back of the baffle? It would be basically a cap above the two wings in back. The reason I ask is that I want to put a grill of some sort there and a top to the box would give me a place to mount it. With three kids in the house, I would like to protect speakers, wires, etc.

Also, do you guys have thoughts about tweeters that would work? From what I've read, the ones in the consoles aren't great. And listening to them I have to agree - they don't do that much as far as I can tell. 

[FullRangeMan]

Visaton didnt saw need of a cap in this project, however there is other projects that use it, you will have listen to say it enhance the sound.

I unknow the console had tweeters, also I dont rec it since you will lost the single point source and will need a complete xover what will drain low level electric energy(music) as heat from the amp.

[windupman]

Thank you. I will do some experimenting and post pictures....

[windupman]

A very nice man near here gave my daughter and me another old console, a Magnavox from the 60s. It has Jensen RP-108 horns and 12-inch woofers, 581206. I was thinking about using the Zenith 49CZ601s as the full-range/mid and the Jensen horns as tweeters. I have read that the horns are really mid/tweeter, but I could cross them over higher.

Also, we now have two tube amps that could be of use. I'm thinking about pairing the above with a small, sealed sub to keep the overall size of the baffles smaller.