Infinity RS3b's Why so harsh sounding and virtually no bass?

ausman1000

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A while back I picked up some very nice looking RS3b's and tonight finally got around to hooking them up and testing them out. All I have to say is.....ouch.....the mids and highs are screaming at me but......where's the bass? I even turned down the mid and high controls to minimum to no avail. Is there a known common problem in this regard? Woofer surrounds look like new so I can dismiss that. Guess I have no choice but to remove a woofer and look at potential x-over problems. Both speakers exhibit the same issue and these are being driven by a 200w per channel Musical Fidelity 6si amplifier. Any info would be much appreciated before I go forward and troubleshoot myself.
 
I will add there is sound coming from all woofers on both speakers but not to the levels that compliment the mids and highs, not by a long shot.
 
Make sure the woofers are wired in series.
A nice big throw rug on a wood floor also helps;)
Good suggestion. I will open these up on the weekend and report back. Since the foam surrounds seem to have been replaced (and who ever did the work did a very nice job) they may have wired them out of phase or not in series as you suggest. No need for a big throw rug, something here is simply out of wack!
 
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Out of phase is likely, which I suspect is what tubed meant for you to check. Wiring them in parallel instead of series would result in more bass, not less (plus it would take effort to do it that way, since the internal wiring isn't set up for it).

If the wiring seems correct, make sure that both speakers are internally wired the same.

if it turns out that there are no electrical issues, I'd next check the woofers' throw and make sure the previous owner didn't screw it up when he replaced the foam.
 
Out of phase is likely, which I suspect is what tubed meant for you to check. Wiring them in parallel instead of series would result in more bass, not less (6 dB more, by my calculations, plus it would take effort to do it that way, since the internal wiring isn't set up for it).

If the wiring seems correct, make sure that both speakers are internally wired the same.

if it turns out that there are no electrical issues, I'd next check the woofers' throw and make sure the previous owner didn't screw it up when he replaced the foam.
Thank you for that info, will definitely report back on my findings on the weekend, much appreciated. I knew these had to sound better because they sound like crap right now!
 
I had the exact issue with a pair I bought used. Pulled a woofer and swapped the wires and wow! The bass was now outstanding. Hope this is your story as well.
 
The technical sheet shows series configuration.

http://www.infinity-classics.de/technik/manuals/RS_IIIA_technical_sheet.pdf

This is in phase when the upper woofer has the incoming positive wire from the network connected to the positive terminal of the upper woofer. Then the negative terminal of the upper woofer is connected via jumper wire to the positive terminal of the lower woofer. The lower woofers negative terminal is then connected back to the crossover network via the negative wire.

Good luck,

Mark K.
 
The technical sheet shows series configuration.

http://www.infinity-classics.de/technik/manuals/RS_IIIA_technical_sheet.pdf

This is in phase when the upper woofer has the incoming positive wire from the network connected to the positive terminal of the upper woofer. Then the negative terminal of the upper woofer is connected via jumper wire to the positive terminal of the lower woofer. The lower woofers negative terminal is then connected back to the crossover network via the negative wire.

Good luck,

Mark K.
Thanks so much, now I have definitive schematic to compare the current configuration to. Maybe I will look delve into this before the weekend!
 
You really only need to pull one to switch wires on the terminals. The result should tell you. If you have bass, and you really should have plenty with 200watts, the wiring is now correct. If not you may have other issues at that point. Can be diagnosed with more info ie confirming phase. To be totally sure you could pull both woofers and confirm above prescribed configuration. Shouldn't be too hard to do.

Mark K.
 
Which woofer should I pull for best exposure to what I need to see, lower or upper?
For instance, if you pull the top one, a purple wire should come off the negative terminal and attach to the positive terminal of the bottom speaker.
Or visa versa;)
 
I would pull them both and check them against the schematic. Pulling one and switching the wires will get them in phase with each other and solve the bass problem, but you still want them in correct phase with the rest of the speaker as designed. Don't assume red or white is positive and black is negative either. When I got my RSII, they had the same problem. One woofer wired out of phase. The correct wiring had one of the woofers with a black wire to positive and white to negative.
 
Pulling one and switching the wires will get them in phase with each other and solve the bass problem, but you still want them in correct phase with the rest of the speaker as designed.

I totally agree, both woofers should be pulled and checked not only for the individual cabinets but also to be sure the speakers are electrically a matched pair. The wiring should be exactly the same in each cabinet and correctly wired in phase with the tweeters and mids.

A quick check for bass output was described for sake of diagnosis.

Mark K.
 
Can you guys also please confirm the original factory orientation of the woofers, that is the position of the spider wires. Here is a pic of mine, shouldn't they both be facing down?

IMG_1950.JPG
 
Here's a link to the schematics which shows the woofers wired in parallel, which is wrong.

I guess I don't understand, can you please explain series vs parallel according to this schematic.

Can you guys also please confirm the original factory orientation of the woofers

Looks correct, as it makes the shortest connection to the intermediate used terminals.

Mark K.
 
I guess I don't understand, can you please explain series vs parallel according to this schematic.



Looks correct, as it makes the shortest connection to the intermediate used terminals.

Mark K.
From looking at that schematic it shows both woofers are each wired in parallel which in reality the two woofers are wired together in series, at least from my experience with the the RSIIa/b including the RS4a/b.
I've measured those woofers and most of them have measured on the low end of 3 ohms.
Wired in parallel they'd measure under 2 ohms, quite low.
I figure some of these woofers have been put back in their cabinets mis wired and out of phase, plus to minus instead of positive to positive for example
The RSIIabs I've come across I basically rewired them until they sounded "right";)
 
From looking at that schematic it shows both woofers are each wired in parallel which in reality the two woofers are wired together in series, at least from my experience with the the RSIIa/b including the RS4a/b.
I've measured those woofers and most of them have measured on the low end of 3 ohms.
Wired in parallel they'd measure under 2 ohms, quite low.
I figure some of these woofers have been put back in their cabinets mis wired and out of phase, plus to minus instead of positive to positive for example
The RSIIabs I've come across I basically rewired them until they sounded "right";)

ok
 
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