Foster Open Baffle Speakers

The latest open baffle speakers I have put together is a 3 way Foster driver speakers. The donor driver came from a pair of Noresco NEC-571  plus a horn tweeter that I picked up from a set of Zenith Allegro speakers.

This project turned out to be spectacular with the push/pull tube amp, almost in the league of openness and fullness as the Speakerlab Super 7's, almost. The Super 7's are really an amazing loudspeaker.

 The original Noresco speakers used a 10" Foster 25E33 alnico woofer with a massive magnet assembly crossed over to the Foster 8F3 three inch full range speaker. The original crossover was used as the crossover point between the woofer and the full range driver is around 650hz.

A foster horn tweeter was included to handle the high end as I found the 8F3 seemed to roll off in the highs.
A 2.2uf cap was used with a crossover point at 9000hz, it seems to have added the high end depth and sizzle that I like.

This combination came out way better than expected. Bass is full and clear, the mid range from the 8F3 is luscious and smooth, very deep and wide. the horn tweeter takes care of the highs in spectacular fashion.

Before I started this project I had an idea as to how this set up would sound, but it came out way better than I expected.

If this is what open baffles are supposed to sound like, then I am a believer now.

Aesthetics came out beautifully with the dark mahogany veneer.

12" Utah Pandore Open Baffles

Another project finished this week is the Open Baffled 12" Utah Pandore speakers.

More bass than the 8" Realistic Americana Open Baffle speakers that I did 2 weeks ago, there is also a compression horn driver for the highs.

these speakers sound very natural and I do not miss the boxed bass that are part of every other speaker.

The results of this project came out much better than my expectations. I am pleased as punch with theses speakers and will most likely keep with the 12" open baffle designs. Although I still have a few 8" coaxial driver that will be featured soon.

And of course these are being driven by a SET tube amp.

Very impressed....

Realistic Americana Open Baffle Speakers

Another idea planted in the depths of November is to start making open baffle speakers using vintage Utah, Realistic, Electro Voice, Knight and Lafayette full range, co axial and tri axial speakers.

The first one I  built was with a full range 8 inch Realistic Americana. I used a nice 3/4 inch plywood with a light mahogany veneer. These are drivers from the late 1960's into the early 70's. Made by Utah and re branded as Realistic. The frequency range is 45-18000hz with pretty high sensitivity.

The legs are from a pair of children chairs that I found at a thrift store.

I got a chance to sit back and listen last night and I liked what I heard. I had to bump the bass and treble for my taste. I found that they worked best around 2 feet from the back wall. I have read that it is best to do an open baffle with full range speakers, simplicity is the key with no crossover phase shift, or in other words coherent.

More to come later on my sound impressions, so far I prefer it to boxed speakers.

KLH Model 17 update

I managed to recap the Model 17 with some Solen metal polyester 5% caps which really help open up these speakers. I also have managed to get the majority of the cabinets back to their walnut veneer glory. Pictures of the cabinets when the job is done.

I really like these speakers and I can see the evolution from these speakers to the New Large Advents that were developed after Henry Kloss left KLH.

The bass is really full and melts into a very smooth mid range. Perfect with a single ended tube amp. I really like these speakers and can see why the Model 6 and the Model 17 have garnered internet attention.

Mid range is nice and forward which is what I like. Bass nice and solid and super tight being in a acoustic suspension box. Over time I tend to prefer acoustic suspension versus a bass reflex system. The bass may not be as low but it sure is tighter.

Update #2

The cabinets are done.

From this....

To this....

KLH Model 17 Speakers

Henry Kloss KLH Model 17's were found today, I have yet to try the KLH models.

This pair will need a bit of work as the nice walnut veneer was painted flat black.

I started to elbow grease some of the paint off, more of that later.

I did add a really thin layer of silicon around the cloth surround, to re dope them and keep the acoustic suspension intact.

More on these speakers at a later.

Vandersteen Model 1 Speakers

Another set of speakers I have been sitting on is this fantastic pair of Vandersteen Model 1 speakers.

Vandersteen speakers are well respected and still in production today.

These Model 1's use the best Vifa drivers that were in production at the time. These speakers use a 8 inch woofer to a 1 inch dome tweeter.  

 

There is a permanent sock around the speaker which hides the driver configuration, luckily this pair came with the original brochure so you can see the speaker without the sock and the specs.

The sound from the Model 1 is very polite and accurate. The bass loading gives nice solid bass for an 8 inch woofer that is clear and clean. The mid range and highs are polite without ever being harsh. Imaging is deep and wide.

These speakers remind me a lot of the Paradigm Control Monitors that I had at one time but more efficient. 

the crossover is not as complicated and therefore allows more efficient signal path to both drivers.

Given Vandersteens reputation in the Hifi world it is a pleasure to come across a set of his speakers.

Ohm Model E Speakers

This little pair of Ohm Model E arrived this week, these are the early versions of this speaker. The early ones used CTS Phenolic Ring tweeters along with a doped surround on the woofer. These are entry level Ohm speakers from the early 70's and would have cost around $150.00 in the day.

The cabinets are real wood veneer and in excellent condition.

The rear terminal plate rattled pretty good when hooked up so I opted to open these up and apply screws to better secure the plates. Since I was there a quick 8uf cap replacement was easy to do. Much to my surprise was the real lack of dampening material in the box, about a t-shirts worth.

Nice and simple first order crossover to the tweeter at 1800hz indicates that the woofer rolls off around the crossover point.

The changes to the internals made a big difference with these speakers, I like the CTS tweeter and the new cap really helps open it up, The boxy boomy sound was eliminated with the addition of ample dampening material.  The back plate rattle was also gone with this the acoustic suspension properties of the system was re established.

How do they sound: Pretty good for a simple speaker system, bass is tight but not super deep with decent output to 50hz, where these shine is the mid range and highs are really nice especially with the single ended tube amp. I am a fan of the original CTS Phenolic ring tweeter it was one of the smoothest paper cone tweeter available and widely used in the early 70's.