[srb]

OK - so listening more to these, the woolier bass (less snap, e.g. upright bass notes sounding more like "wob" than "dop") is the one thing about these that kind of bothers me compared to my Philharmonitor ScanSpeak woofer.

Not too surprising that an inexpensive $10 - $15 woofer is much less articulate than a $200 ScanSpeak Revelator, one of the best midbass drivers made.

It's possible you might improve some smearing due to cabinet resonances with a few braces, but I  wouldn't expect night and day improvement.  BTW, I've never used anything smaller than a 3/4"D dowel.

The nice thing about modifying a pair of speakers, is that if you do one at a time you can easily compare it to the unmodified speaker.

[charmerci]

It's possible you might improve some smearing due to cabinet resonances with a few braces, but I  wouldn't expect night and day improvement.  BTW, I've never used anything smaller than a 3/4"D dowel.

Got it.  Thanks.

[Letitroll98]

Should I post this in Enclosures instead?

No, we love ripping apart things and modding them on C and C. 

[dB Cooper]

Technically it could go either way but seems more relevant to C&C... to me.

For the audio hobby to thrive, there needs to be an entry-level, even if it is looked down on as 'mid-fi' by some.

BTW, there are quite a few people here who know about the Last-i-Clay/plasticine/Plastilina permanently soft clay advocated by Frank at Audio by Van Alstine. It can have surprising benefits especially with stamped baskets which are prevalent at the El Cheapo end of the market.

[charmerci]

BTW, there are quite a few people here who know about the Last-i-Clay/plasticine/Plastilina permanently soft clay advocated by Frank at Audio by Van Alstine. It can have surprising benefits especially with stamped baskets which are prevalent at the El Cheapo end of the market.

I'm very familiar with that. Simple dowel bracing does the same for the cabinets.


I'm kind of reluctant to go ahead with the project because it will void the warranty.

[karnana]

thanks for the info!

[charmerci]

I put one dowel in, in one speaker (side to side) and it does seem to help tightening the bass a bit. In a while (maybe next Mon/Tues. my days off) I may get some non-drying clay to coat the port tube and the driver basket. But as you can see below, the back panel is well connected and the space is tight. We'll see. I may back out of this if I fear busting something.


 


 


  


I'm especially worried about that above red connector. It doesn't pull off easily.

[Doublej]

I'd take a good long look at the connector to see if has any type of tab that needs to be pushed or pulled for it to be removed without breaking it.

[charmerci]

I'd take a good long look at the connector to see if has any type of tab that needs to be pushed or pulled for it to be removed without breaking it.

Well it does but I'd first have to snip a couple ties holding the speaker wires to the cabinet then disconnect them from the circuit board to get the back panel away from the box to see it and grab it properly.

[charmerci]

Visiting friends and other things got in the way. There was no non-drying clay in my small town so I had to buy it on-line.

I took it apart and added the clay to the woofer basket (most of it) and around the port tube which comes off the back with three screws which made it easier to do the rest. I also added an top to bottom dowel and two side to side dowels that had to fit below the port. I also added a bit of clay on the inside of the back panel that wasn't covered by the D-amp. I used about 2/3rds of a pound of clay for both and the side  dowelswere 6 1/32" in length.

I've only had a chance to listen to it a bit - but it certainly shows that the enclosure is definitely the weak (read cheap!) part of this speaker. It tightened up the bass that I complained about earlier. Bass lines no longer sound like wwwwooooooooommmmm, wwwwoooooooommmm.

Much better, highly recommended. This almost makes me not miss listening to my Philharmonitors - though I'll have to do more long term listening. It's getting close though.

[maty]

https://www.diyaudio.com/forums/multi-way/320206-jbl-lsr305-tweaking-post5817738.html

[wushuliu]

[FYI for others, Maty is referring to someone adding cheap barrel ferrites to the JBL internal amp output wiring for improved sound quality]

IOW, since this is a powered speaker if you really want to take things up a notch the answer(s) will with the amp.

EDIT: Ok, I see you're tying this into your previous experience using ferrites on passive speaker crossovers. Never heard of that, so won't comment. But as for the JBLs, I believe the response you got before is accurate:

Not sure if i get this right, but the JBL example seems to add ferrites to the output of a class D amp, which by definition contains lots and lots of HF garbage. Ok, it is not audible on its own but it certainly finds ways of entering upstream components. So the ferrites cut the garbage down a bit...does not seem so strange.

I am not surprised adding cheap ferrites to the JBL amp output wiring would potentially improve performance, especially as odds are the JBLs are using the cheapest design possible (business is business), not lowest noise.

[akmh]

My Samsung smart TV has an optical (audio) output meant to be connected to a soundbar. Is there such as thing as an adaptor that will allow an optical out to be connnected to XLR (for this speaker).

You can use a cheap optical to RCA DAC. Like $10 on amazon. The RCA cable tip termed to pin 2 and RCA shield termed to pin 1 on a XLR connector. You can float pin 3 or if your worried about noise, strap it to pin 1 so its grounded. No need to go balanced into home theater speakers. Your cables are probably less than 6ft anyways!

[akmh]

Visiting friends and other things got in the way. There was no non-drying clay in my small town so I had to buy it on-line.

I took it apart and added the clay to the woofer basket (most of it) and around the port tube which comes off the back with three screws which made it easier to do the rest. I also added an top to bottom dowel and two side to side dowels that had to fit below the port. I also added a bit of clay on the inside of the back panel that wasn't covered by the D-amp. I used about 2/3rds of a pound of clay for both and the side  dowelswere 6 1/32" in length.

I've only had a chance to listen to it a bit - but it certainly shows that the enclosure is definitely the weak (read cheap!) part of this speaker. It tightened up the bass that I complained about earlier. Bass lines no longer sound like wwwwooooooooommmmm, wwwwoooooooommmm.

Much better, highly recommended. This almost makes me not miss listening to my Philharmonitors - though I'll have to do more long term listening. It's getting close though.

Dampening the speaker cabinet is trick used by the world best speaker manufacturers to achieve sonic perfection. Anyone not doing it is simply building a effects generator. This works on almost ANY speaker. Also dampen the speaker drivers! Cover those parts in silicone! Rock wool on the inside is great too!

[akmh]

I put one dowel in, in one speaker (side to side) and it does seem to help tightening the bass a bit. In a while (maybe next Mon/Tues. my days off) I may get some non-drying clay to coat the port tube and the driver basket. But as you can see below, the back panel is well connected and the space is tight. We'll see. I may back out of this if I fear busting something.


 


 


  


I'm especially worried about that above red connector. It doesn't pull off easily.

You should get rid of all the crimped connections! This is a speaker for christs sake its going to vibrate the hell out of those connections. Just solder the wire directly to the board!

[charmerci]

You should get rid of all the crimped connections! This is a speaker for christs sake its going to vibrate the hell out of those connections. Just solder the wire directly to the board!

I think I've done what I can with the speaker. Anyways, I don't have solder/soldering iron.