[dliscomb]

Greetings all,

I have a pair of Sony SS-U610 sealed 3-way speakers connected to my NAD 7250PE receiver (https://nadelectronics.com/wp-content/uploads/2017/06/7175PE-Data-Sheet.pdf).   I like them well enough, but the backs blew out recently and so I re-glued them.  No more rattle! Yay!

Whilst mucking about inside, I found the crossover is: 2 caps.  One each for the mid & tweeter, with the woofer connected directly to the posts.  That just don't seem right, making the woofer hafta handle highs and lows.
So, my idea is to replace the caps with a new passive crossover, but I'd like some feedback before throwing ~$100 at them.  I'm still new to the fundamentals of speaker design, to say nothing of crossover design. 
Is this a crazy idea?

Apologies if this seems off-topic, but I didn't see a generic 'modding', 'home brew' or 'speaker' room in which to post.  The others seemed more specific to other types of speakers.

Kind regards,
Drew

[mix4fix]

I will say this:
I don't know anything about those speakers so I don't know if they are considered vintage or just crappy speakers. If they are vintage, don't screw with them. I made that mistake before.

If they are crappy, you could mod them. Or, pawn them off and buy speakers you like.

[Letitroll98]

This is not the least bit unusual for cheap speakers.  The caps protect the mid and tweeter from low frequency signals that might harm them, the woofer and midrange roll the highs off naturally and won't be damaged by signals they can't reproduce.  Besides the fact that you have none of the specs on these drivers that would be necessary to design a crossover, there's very little reward in trying to make a silk purse out of a sows ear.  Cheap upgrades that might work better would be to put in a couple of braces, wooden dowels cut for a friction fit work well, and some non hardening clay on the driver baskets and interior corners of the cabinet.

[dliscomb]

Many thanks for the replies!

[dB Cooper]

Apologies if this seems off-topic, but I didn't see a generic 'modding', 'home brew' or 'speaker' room in which to post.  The others seemed more specific to other types of speakers.

Kind regards,
Drew

Either the DIY, Cheap n' Cheerful, Enclosures (=speakers) or Vintage circles. Probably DIY or Enclosures would be my suggestion. I agree with Letitroll's points though. Maybe a little judiciously applied non-hardening clay (cheap and effective) but, unless these were pretty good speakers to begin with, it's  a question of how much effort and expense is worthwhile.

[Mudjock]

I usually am up for a good modding project, but after looking up the Sony's, I have to agree with the other posters.  The "crossover" you have is just designed to protect the drivers.  The woofer probably has a very simple motor with relatively high inductance, so that it rolls off naturally at higher frequencies.

I have a friend who used to have a similar set of speakers and wanted to downsize.  He borrowed a pair of my "Lithium" speakers https://sites.google.com/view/sehlin-sound-solutions/home and 5 years later still has them.  Those are a small 2-way bookshelf speaker with a 4" woofer and dome tweeter, but extend pretty cleanly to 50 Hz.  You will be very surprised at what a properly designed bookshelf speaker can do with your NAD receiver. 

Since you are looking at tinkering with speakers, I would suggest your time and effort would be better spent starting from a kit or diy design depending on your proficiency with woodworking and/or soldering.  Some of my designs are based on commerically available flat pack speaker cabinets, while others involve more woodworking.  You would still have to do driver cutouts, assemble crossovers, and wire everything together in any case.  There are some kits that have that done for you - check out vendors such as Parts Express, Meniscus, and diysoundgroup for some budget friendly options.

[dliscomb]

@DB Cooper, thanks for the suggestion.  I'll give plasticene a try and see if that helps things.

[dliscomb]

@mudjock, thanks your patient reply to a neophyte question.

I think they sound pretty all good, now that the back is fixed.

Super gratitude for the link to the Sehlin Sound site!

Kind regards,
Drew

[dB Cooper]

@DB Cooper, thanks for the suggestion.  I'll give plasticene a try and see if that helps things.

It helps everything I have tried it on. Worth checking out the article in the old Van Alstine 'Audio Basics' newsletter just for some general guidelines though.

[Letitroll98]

Note that the Elac B6.2 are on sale at Amazon for $150 a pair.   If you can scrape up the scratch for these they'll blow away those Sonys in every single category.   Best Buy will price match.

[mix4fix]

Note that the Elac B6.2 are on sale at Amazon for $150 a pair.   If you can scrape up the scratch for these they'll blow away those Sonys in every single category.   Best Buy will price match.

That goes along with my theory of don't breaking what's working, and getting something that's better. I can't comment specially on those Elac's, but it is a start.

What would be you budget if you bought new speakers? You don't have to buy new. Used is definitely a route to take when it comes to speakers.