Bose 501 Series IV Tweeter Upgrade

Status
This old topic is closed. If you want to reopen this topic, contact a moderator using the "Report Post" button.
I would like to upgrade the tweeters in my older Bose 501 Series IV speakers. There are two in each cabinet, arrayed at 90 degrees, and held by a screw through an extended bracket into the back of the tweeter magnet.
Checks with Bose and Parts Express have elicited the information that any replacement should have a FS of 1000 or less and that the crossover to the woofer takes place gradually from 1500 to 2500 cps.
If anyone has tried such an upgrade, or knows of a likely prospect, I would appreciate your expertise.
 
Thanks, but...

Thanks for your offer, but the 501 Series IV tweeters are still available new from Bose for modest amounts. I just replaced both of the woofers with the drivers recommended by Bose (from Parts Exress) and the speakers now sound acceptable -- even though they are old.
My goal is to take advantage of the tweeter array design that creates a broad sound stage. Should it be possible to upgrade the tweeters with devices that generate the detail and response of a Vifa or Seas then the 501s will still have some benefit to me.
Parts Express noted the difficulty would likely be finding a tweeter that would bolt mount by its magnet to the 501 tweeter attachment arm. This configuration requirement might sink the project.
Like your idea of turning the cabinets into subs. I just purchased the Dayton sub-120 and it works well with the 501s as part of a home theatre arrangement.
 
The "broad soundstage" is a function of things other than the way that Bose put the tweeters. If what you mean is good off-axis HF response, then yes, the arrayed tweeters are one way to achieve that result.

You can likely find tweeters to sub in the Bose, but they will not look like the Bose part. The Bose tweeters are honestly cheap devices. The Vifa and similar tweeters are not so inexpensive.

You would have to build another mount method, and perhaps modify the round flange(s) to fit the space in your box.

The freq response down to 1000Hz is difficult without using a cone type tweeter, or a dome of somewhat larger size than the usuall 3/4" to 1" diameter dome... although there may be some that will suffice. One would have to take a close look at the specs.

I'd suggest that you stick with the stock parts, unless you want to essentially build a new speaker, since any new tweeter will require changes to the xover in order to function properly anyhow. That's because of different response curve, different real world impedances, and most importantly different sensitivity.

There's rarely any easy way or free lunch in these matters...

_-_-bear

PS. if you measured the response of those tweeters @ 90 degrees and recessed in the cabs, without much of a baffle, and with sharp edges (have they changed that with the newer models) I think you'd be rather agast at the way it looks... :spin:
 
Status
This old topic is closed. If you want to reopen this topic, contact a moderator using the "Report Post" button.