L7 Breakup

[John W]

Hi everyone.
I recently got a good deal on a pair of L7s. The drivers are all in fine shape and functioning great, unfortunately the cabinets and grills are a little messed up. They are repairable, but even so, my room wouldn’t be ideal for the speakers. Placement would be a problem. My wife thinks they are ugly as sin too.
I am considering a separation… of the drivers.

What I am thinking is placing the top 3 drivers into their own bookshelf cabinet, keeping the same time-aligned angle and baffle size, and putting the LE120H drivers into a separate pair of subwoofer cabinets like the Synthesis S3S.

http://manuals.harman.com/JBL/HOM/Te...ck%20specs.pdf

I figure it would be easier to align the woofers to the room if they were separated somewhat from the rest of the drivers.

Good idea or waste of time and speaker?

The current L7 configuration has the LE120H crossing in at 180hz. Is that too high for what I am considering?

[Earl K]

Good idea or waste of time and speaker?

- I think it's a good idea to make something that you and the family will like to keep around.

- Look to the L3 for inspiration ( you'll just end up with a L3 plus midrange ) . That model runs full range using the same 8 inch woofer ( obviously , its' cabinet is tuned lower ) .

The current L7 configuration has the LE120H crossing in at 180hz. Is that too high for what I am considering?

- Yes, IME, you want to build a speaker enclosure that does nicely on its' own, down to @ 70 hz .

[John W]

Finished the first half of the L7 breakup.

The top section with the 035TiA, 704g, 708g and slightly modified NL7 crossover have been put in there own boxes. The boxes are roughly 1 ft3 tuned to 35hz. The width, baffle layout and angle are the same as the original L7s, 9.1/2 in. Otherwise they are 22 3/8 tall 10 3/8 deep on top, 13 5/8 deep on the bottom. There is a 5.25 x 2” vent out the back.

The veneer is a nice quarter sawn cheery with cheery corners that have a slightly larger radius than the original. They are pretty light right now, but should darken up a fair bit in the next year or so.

[John W]

The L7 has two separate crossover boards, which works out great. I modified the upper section by removing the 90uf capacitor on the 708g input and replacing it with a solid wire link. This basically removes the 180 Hz high pass on the woofers and lets them run as low as they’ll go.

Here’s a picture of the modified crossover, a plot of the response, and a picture of the speakers on the shelves in the living room that were the reason for the modification.

[John W]

They sound great as is. Even without the subwoofer, they have a nice low-end.

Next step is a pair of LE120H subwoofers. I haven’t been able to trace down the actual TS parameters for these drivers. Does anyone have these? From searching around the forum it looks like a good alignment is 3 ft3 tuned to 30Hz which appears to be the approximate size of Synthesis subwoofer.

[Robh3606]

Very nice John. Not surprised on the low end with the 8's I have L3 and they are nice 2 ways.

Rob

[sourceoneaudio]

L@@@ks very good John. Nice touch on the rear panel, looks factory.


Jeff
J/S-S1A

[4313B]

I always look forward to your posts John!

Outstanding as always.

[DavidF]

"... here's a picture of the modified crossover, a plot of the response, and a picture of the speakers on the shelves in the living room that were the reason for the modification.

John, where did you have the enclosures when you ran the plot? Curious if they were on the stands out from a boundary.

The beading around the trim pieces is a very nice touch.

DavidF

[John W]

John, where did you have the enclosures when you ran the plot? Curious if they were on the stands out from a boundary.

The beading around the trim pieces is a very nice touch.

DavidF

The enclosure was on the edge of a low table, sort of in the middle of the room. The 200Hz dip is likely due to boundary issues.
For curiosity, I tried measuring on the shelf, but I couldn't adjust the mic to reach high enough. The whole setup is not the pinnacle of accuracy, but gives a pretty good idea on how they behave within the room.

[Titanium Dome]

Good looking, indeed.

The LE120H-1 was used as a sub driver in the Citation 5.4 and in the Fosgate Audionics CSS220 THX sub. I have three of the latter, but they're buried in the dungeon, and my back's out of sorts.

Maybe I can dig one out tomorrow and give you a volume estimate.

[Zilch]

http://audioheritage.org/vbulletin/s...35&postcount=7

[Titanium Dome]

http://audioheritage.org/vbulletin/s...35&postcount=7

Ah, well, there it is. Thanks, Zilch (and Giskard). Now I can continue to rest my back.

[Zilch]

Now I can continue to rest my back.

Not so FAST, Advil breath.

Well still need the port dimensions, and the Fosgate volume may be different from the other two....

[Titanium Dome]

Oh, all right.

..and it's Flexeril breath to you, Mr. Flexeril breath.

I'll be back in a minute.