Aquarius 4 modifications

[DanMan]

Hello all; this is my first post here though i've been reading the website for years. Hope this post is in the correct place.

I'd appreciate feedback on my plan to modify my Aquarius 4's.
I have a pair I use in the living room where its impossible to get in the 'sweet spot', so the application is perfect for the A 4's.

My idea is to get the tweeters to disperse radially in the same direction as the woofer dispersion... i.e. horizontally instead of vertically.

To achieve this, my plan is to remove the tweeter & board from the back of the cabinet, close the hole, recut the top of the cabinet to fit the tweeter & board and affix them to the top of the cabinet such that they disperse radially in the horizontal.

For the sake of discussion, lets assume that my cuts/fills/speaker handling/rewiring is flawless. Also, resale value is not an issue.

My question is .. what do y'all think about the idea? Has anyone else done this? Any comments/advice/suggestions are much appreciated!

[Zilch]

Why do you believe they presently disperse vertically?

http://www.audioheritage.org/images/jbl/sketches/thumbs/figure06_small.jpg

[DanMan]

I think the "lens assembly" in front of both the woofer and tweeter divert the sound waves 90 degrees... no?

[macaroonie]

Why don't you build a rough dummy top and try it out. If it works for you then cool they are your speakers. If it does not then at least you have not trashed anything.
For what it is worth the second generation had multiple tweets probably to address this very issue.
The ones you have depend on there being reflective surfaces behind and around the speaker and will be subdued in the top range if that is not the case.
I really enjoyed mine and had them I suppose ten years.
As a last thought are your adjustable L pads clean and tidy, after all this time they might need a clean.

[DanMan]

thanks for your advice - i took it to heart - "non destructive testing" what a great concept! wish i had thought of that!

here's what i did - i had a leftover box from an old pair of T545's (that i hope to one day hook up to my 12v convertor and turn a room into a car stereo room reminiscent of my days in my old granada... but until then this box worked great for temporary housing for the aquairius tweeter.
the install was really easy - nearly a perfect fit - though i did construct a baffle board so that it would have an air-tight chamber...

anyway, here's my findings:
the tweeter on top of the cabinet sounds a lot brighter and more directional towards the listener. it sounds more like a standard "hi-fi" speaker than before. it actually took a long time to get used to it, probably becuase I'd heard it the old way for so long. the sound is somewhat 'strange' however, being that the woofer is omni-directional and although the tweeter is still omni-directional, it points towards the ear - so the sound from the woofer and the tweeter hits the listener in a different manner, making the sound a little obfuscated. in the standard tweeter placement the sound (emminating from all directions) has more of a magical sound, it sounds a little more "cohesive" or "together" in its original configuration. i played with the l-pads till the volume of the highs were about the same, but still the original configuration has more magic in its reproduction than with the tweeter on top. its as if the sound emminates from the entire speaker cabinet and the cabinet acoustically appears to be much larger than it actually is. whereas with the tweeter on top, the sound is clearly emminating from the top of the speaker, its much easier to point to the source of the sound with the tweeter on top. tweeter on the back is just a magical combination... hey what do you know.. JBL knew what they were doing.. ;-) I'm putting the tweeter back in the cabinet and getting back to my day job!

Thanks again for the advice. pictures attached for your amusement....

[Zilch]

Cool experiment! :thmbsup:

It'd be fun to measure the dispersion pattern of that lens..... :yes:

[Don C]

Here's how JBL cured the problem on a later version.