Jensen X-40?

[JKent]

Picked up a pair at a local yard sale. I've heard of the Jensen name but can't find a thing on the web except a 1966 ad. Haven't listened yet or opened them but they're roughly the size of my AR-4x's. Nice walnut veneer. 2-way. 8" alnico woofer. 3" tweeter. Acoustic suspension, I believe. Made in Chicago. photo shows the Jensens with my "ARvid" speakers--Avid 100 guts in AR-4x cabinet. The Jensens may appear bigger because of the bigger grille.

Anybody know anything about these?

[JKent]

Started on them today. They have a kinda cool '60s grille but one is torn so the cloth will have to be replaced. Unfortunately, the cloth is wrapped around the front baffle and the baffle is glued and nailed in place.

Access is through the back. The panel is attached with screws around the perimeter and it comes off easily. Not much obvious effort to make these airtight. There's no sealant or gasket for the back panel and the drivers have cardboard gaskets.

Only about 1/8" taller than my 4x's, otherwise the same size. Stuffed with fiberglass. The crossover has a level control pot for the tweeter, 2 inductors, a 17uF cap and a 2.7uF cap. The caps were the infamously leakage-prone black Callins jobs with red ends but amazingly (to me) the ones I removed from the first speaker measured spot on.

The smaller inductor was positioned INSIDE the large one! And they're held in place with twist ties and wide electrical tape.

I used parts I had on hand: 2.7uF mylar film and for the 17uF, two 8uF NPEs and a 1uF poly. A pic of the rebuilt xo is below. I moved the small inductor as far as I could from the big one.

The drivers were easily removed. They're held to the baffle with 4 machine screw studs and kep nuts. But removing the baffle was another matter! Once the xo and drivers were removed I used the brute force method: Hammer and a block of wood (note to self: Next time, less brutish). So I managed to break the particleboard baffle but I'm gluing it back together.

I don't want to apply the new grille cloth the same way. It's virtually impossible to remove and I don't care for the way the grille/baffle protrudes from the frame. So I think I'll trim the baffle so it fits inside the cabinet, then recess it a little. The rabbet around the front is only about 1/4" deep so I'll make new grille frames out of 1/4" Masonite or, if I can find it, 3/16" MDF.

[JKent]

Finished evrything but the grilles. Ordered some 3/16" MDF from Michaels online. The sheets are "almost" the perfect size. I think I need 10 x 19" and the ones I ordered are 10 x 20".

One respected speaker expert said Jensens were "pretty crappy". I disagree, mostly. The cabinets are very well made, with nice walnut veneer. I don't like the way the grille/baffle was attached and they don't seem 100% airtight. The woofer is a nice 8" cloth-surround Alnico job but not as nice as AR's. The tweeter is a pretty generic 3". Crossover seems appropriate with 2 caps, 2 inductors and a level control. Speaker terminals are crappy screws.

I banged the baffles out and trimmed them down to fit inside the cabinet, recessed about 1/4". Made cleats to go around the perimeter to glue the baffles to. I didn't cut the baffles absolutely perfectly, but had some black Phenoseal on hand and that filled the gaps. The veneer was in very good shape (except, inexplicably, for 3 screw holes along the long side of one speaker). I just did a light sanding (220) and then applied 2 coats of wipe-on poly. I may do more with that. Painted the baffles black.

When reinstalling the drivers I tossed the tweeter's paper "gasket" and used the caulk from PE. Tried to also use that on the woofer but the studs are so short there was no room for more thickness, so I just torqued the nuts down and hoped the layered paper gasket would work.

Hit a snag when putting the woofers in. The cleats got in the way a little. Trusty ol' Dremel fixed that 😉.  The xo is attached to the back panel so a little bit of a juggling act attaching the leads, replacing the fiberglass and reattaching the back panel. The panel is held on with 8 wood screws so I added some thin weatherstripping to try to make the best seal. Added Daka-Ware knobs to the level controls (either the knobs were missing or they were never there).

So I've been auditioning them. Listened to them as a stereo pair but also played several selections in mono, switching between 1 Jensen and 1 AR-4x. They're similar designs and of the same era so this seemed like the best comparison.

The Jensens don't have the perceived bass that the ARs have, and although they have similar woofers the ARs have a longer throw and are "looser". Neither the AR nor the Jensens do very well with the 3-finger test but the ARs were apparently designed that way, with their porous dust caps.

Despite their second-place comparison to the ARs, the Jensens sound very good to me. Placement in my shop is not ideal. They're far out from the wall and much too close together but the initial impression is that these are very listenable speakers. I listened to a variety of vocal and instrumental CDs as well as a test CD. Everything sounded good, including some favorite recordings that I've listened to hundreds of times. Low-frequency isn't AR but it's good. Likewise dispersion isn't AR. But these would be good speakers in a smaller room. When I get a chance I'll take the ARs off the shelf and put these up there to give a fairer listen. I imagine the bass will improve.

 

 

Edited August 10, 2023 by JKent
removed pics

[Aadams]

19 hours ago, JKent said:

One respected speaker expert said Jensens were "pretty crappy". I disagree, mostly.

You made me look.  You were correct.

Until the mid 1960s Jensen was known for state of the art sound reinforcement  and home music systems.  Altec, JBL, Bozak, Klipsch, all competed with Jensen on  the high end.  When the founder, Peter Jensen ,died in 1961 the company began to slide and eventually was sold and resold into oblivion.  Exact copies of Jensen speakers for a variety of vintage electric music instrument applications, Fender for example., are still made an sold.

https://www.jensentone.com/history-jensen-loudspeakers

https://www.psaudio.com/blogs/copper/jensen-the-man-the-company-conclusion

[JKent]

Thanks for that research. I was struck by the statement "While the company continued to manufacture speaker systems for decades after its founder’s death [in 1961], it essentially became a me-too brand, building speakers that offered solid value but uninspiring performance: the audio equivalent of, say, Buick". 

I'd agree with that assessment. A Buick tag line of old was "Wouldn't you really rather have a Buick?". Um, no. But a Buick is still a perfectly good car and I'd say the same of the '66 Jensens.

[JKent]

So the Jensens are finished and I'd say they are very listenable speakers. I put them on a shelf with my restored AR-4x's. Here are some impressions after some brief listening:

• The Ar-4x has better deep bass and overall seems "fuller". Highs are somewhat rolled off.
• The Jensen X-40 is a bit more efficient (louder). They are not rolled off so seem "crisper". The vocals seem more forward.

I listened to some Miles Davis, Dire Straits, Roy Orbison and Bela Fleck. Playback equipment included a Tivoli CD player, Technics CD changer with Schiit modi 3 DAC and an iPod. Preamp is a DB Systems DBR-15B/2A. Amp is a DB Systems DB-6A, both recently upgraded.

Here are some final pics.

• One reason the Jensen's low bass doesn't match the AR's is because the 8" woofer is more like 7". 
• After modifying the front baffle as described in previous posts I made new grilles using 3/16" MDF and CharlesCraft Irish Linen (inexpensive at Michael's and one 20x24" roll was just the right amount). The MDF was too thin for staples so I used Aleene's Tacky Glue. Works great. The finished appearance reminds me of the European ARs with their thin face frames.
• Just for comparison, the 3 speakers below are Rompicollo, AR-4x and Jensen X-40 (if you've never heard of Rompicollos, they're a Johnny Richards design from a few years ago, using PE Buyout drivers. I built them in some veneered cabinets from the Sal. They also have CharlesCraft linen, while the ARs have the heavier stuff from 123 Stitch).

[JKent]

Finished, but one more step: Got a very inexpensive set of banana-to-spade adapters on ebay.

 

[Norman Nicolai]

Nice job, Kent!

I don’t normally look at this section of CSP, but noticed your post when I was thinking of asking a question about another non-classic speaker brand, Thiel’s.

BTW, I use those banana adapters on a lot of my equipment, but especially on vintage receivers. They’re useful on tube or vintage receivers where the speaker connector screw is tiny and there is little space between screws. It’s impossible to use higher quality wire, like a 12 or even 14 gauge wire for speakers because the space is so tight. They fit perfectly in a situation like that, and it makes changing wires a snap.