Jumper Strips on LSi25's

pmckeealaska

OK...I have asked this question in other threads already and havent been able to get an answer about it so I'm started a seperate thread just for it. I have a pair of LSi25's that I have been trying to tweak lately for the best possible bass response. I used to connect my Audioquest Subwoofer-X cables to the "line level in" input of the subwoofer on each speaker. Now I have the cables running into the "lfe in" input and noticed an improvement in bass. However, some have told me I should remove the gold jumper plates between the the top and bottom binding posts while others (including tech support at Polk Audio) have told me to leave them on. What do others on here think? For me it wouldnt be an issue leaving them off but, to my ear, the bass sounds better with them on. If it will damage something to leave them on then I'll remove them. If not, I'd rather they stay on. I guess I should also play with the XO frequency on my reciever to try and get better bass (it's set at 80Hz now). For right now though, I'm in serious need of some advice on these damn jumper strips!!:mad:

cokewithvanilla

I thought the user manual says to take them off if using the LFE in. I noticed that the bass is more boomy when using LFE in.

pmckeealaska

Well, yes, I read that in the user manual as well. But like I said, I called Polk Audio tech support on Friday and the person I talked to said to leave them on. I'm not ure what role the jumper strips play anyway. If its going to hurt the speakers then I would remove them since I'm usiing the LFE in, but the bass response I get is just so much better with them on and I have to go with what tech support tells me. I also changed the XO frequency on the reciever to 60Hz and that's where it sounds the best to me. Again, if it will hurt the speakers to leave the jumpers on then I'll remove them. However, until someone who is confident in what they're telling says it will hurt the speakers, I'm going to leave them on cause I like what I'm hearing! I had them off for most of the day and bass was just lacking!

pmckeealaska

No question to me...the bass is much better with the jumpers on. I just cannot imagine why I would want to remove them unless i risk hurting my speakers. Until someone responds to this thread with a good reason to take them off, I'm keeping them where they're at!

kawizx9r

Well I recall someone asking this question and I explained why/etc....not sure if it was you or not.

Anyway, it's suggested that you remove the jumpers.

The jumpers are only there to receive a signal via speaker wire (from your amp/avr) and send that signal to the internal amplifier of your LSi25's for your subwoofer. This is mainly the case for those that lack a dedicated sub out from their AVR or preouts (or convenience, because they don't want to run more wires).

When utilizing the line in (from the sub/lfe out or preout of your AVR), you're sending your sub+sub amp it's own signal which in turn means you don't need the jumpers in place.

Sending two signals to a sub is a no-no. You wouldn't connect a subwoofer to your AVR utilizing both LINE IN and LFE at the same time would ya? Don't do it to your LSi's!

-Freddy

pmckeealaska

What can I say? It sounds better to me with them on and I don't see how it could damage anything? Plus,Polk tech support told me to keep them on! Why would they tell me to do this if it would hurt my speakers?

kawizx9r

pmckeealaska wrote: »

What can I say? It sounds better to me with them on and I don't see how it could damage anything? Plus,Polk tech support told me to keep them on! Why would they tell me to do this if it would hurt my speakers?

If you're so inclined to keep them on, then why even post a thread asking whether to use them or not?

Keep them on, I wouldn't.

pmckeealaska

The reason I posted was to find out if keeping them on would hurt the speakers; that's why I asked. So far, no one has told me that keeping them on would hurt my speakers. Plus, why would Polk tell memto keep them on in the first place.'just looking for more opinions on the matter, that's all. I appreciate your input but you haven't given me a clear reason why keeping them on would hurt my speakers...

kawizx9r

When the question was asked pertaining to stand-alone subwoofers, it was advised NOT to utilize multiple sets of inputs (LFE+Line in or speaker terminal IN) at the same time because the 'boosted' signal would introduce alot of distortion to the subwoofer. Playing this signal at what would seem 'moderate' volumes to us would actually be close to the subwoofer's limit thus damaging the subwoofer.

I would assume the same for powered towers (I applied this logic to my old Polk RT1000P's).

In your case, I'd suggest you only utilize the LINE IN on your towers from your AVR's LFE output. That way, you can adjust the level+cut off (if you'd wish to bring it lower than the stock cut off freq) from your AVR without having to go behind the tower and turn up/down the gain.

pmckeealaska

Ok. Thanks. That makes sense to me. I'll change it back now.'inwonder why Polk tech support would have told me to keep them on? Weird. At any rate, t be safe, I'll switch back to the "line in" until I can talk to Polk again. Thanks!!

ben62670

Keep the straps off. You need to adjust the receiver to increase the DB's on the LFE. Kawi has it right.

pmckeealaska

Got it. I've kept them on but now have the subwoofer cables going into the "line in" on the subwoofers. Will this work? Any danger of hurting the subwoofers this way? I hope not, since this is how I had things up until yesterday. I just wish I could get the bass response with it this way the way I did using the LFE in with the strips
on. What can I say? It sounded better to my ear that way, but I certainly don't want better bass and then risk hurting my speakers!

ben62670

remove the straps if you are going to use the RCA cables at all.

kawizx9r

Louder bass does not equal 'better bass' since I'm guessing it just sounds louder (for reasons stated above).

Adjust the LFE output and subwoofer options found on your AVR, and I'll bet that you'll find the subwoofers sounding better than ever before.

pmckeealaska

OK, so I have put the subwoofer cables back to the "line level in" on the 25's subwoofers and have taken the jumper strips off. I also adjusted the XO frequency on the reciever to 60Hz and the bass sounds pretty damn good to me. However, and this is driving me nuts, on the manual for the 25's it says that if I use the hook up option #2 (which is how I have it now), figure #6 says that the sub setting on the reciever should be set to "no" or in the case of my reciever "off". However, when I do this, there is absolutely no bass coming from the subwoofers....zero. So I have no choice but to set my recievers subwoofer setting at "on" to get any sound out the 25's subwoofer. WTF? The whole explanation on the manual is completely confusing. Even the drawing on figure #6 doesnt label the back of the speakers correctly. It shows the subwoofer cable going into something labelled as "subwoofer in", which I take it to mean the same as the "line level in" on the speaker. I mean, for god's sake, I spent $3000 on these speakers and the manual is the lamest and most innacurate thing I've ever seen. All of the this **** around has left me feeling stessed out to the max.

So, to be clear, the way I have it set up now (subwoofer cables to "line level in" of the 25's subwoofers, with the jumper strips off and reciever setup section set to subwoofer "on") is the correct way to go? From here I can just adjust the XO frequency on the reciever till I get the bass sounding the way I like it? I'm not going to hurt my speakers like this, correct?

kawizx9r

I'm a bit stumped on the manual thing, are you sure you weren't reading something else (that happens to be stated on the same page) on the manual?

If you have your LSi25's connected to the sub out on your AVR, there should be no reason to set the Sub out to OFF/NO on your receiver. It's pointless and just stupid so don't worry, you're right in setting it to YES/ON.

As for the XO, you can adjust it if you really want to but I'd just let it be. Your LSi25's are already crossed over at a certain frequency (in regards to the tower's midrange drivers themselves). You can however adjust the LFE level on the fly now.

I've always experienced slightly cleaner bass as well when using the line in inputs as opposed to speaker wire+jumpers to the binding posts of my speakers.

kawizx9r

Just wanted to add, I took a look at the manual and it too states that when using the line-in...to remove the jumpers.

Btw, wasn't sure if your 25's had a crossover knob or not but after looking at the manual it does.

My best recommendation to you is, set the crossover at it's HIGHEST on your 25's alone and use your receiver's XO setting to adjust the cut off frequency. This should be the most convenient way (you can do it via remote from your sweet spot) as well as eliminating the possibility of using dual filters for your bass. You can get a nasty bass hump if you set them both (knob on the 25 and AVR settings) close to each other or even worse, at the same cut off freq.

pmckeealaska

Thanks Freddy. That's exactly what I've done. I have the frequency knob on the 25's subwoofers turned all the way to the right to avoid any dual filtering.

I have to reiterate though how completely unhelpful the manual and it's figures are for these speakers. Polk says that the LSi's are their top line of speakers. If this is the case, you would think they would put out and more detailed manual rather than the lame **** 5 or 6 page one that comes with them now. I just don't get that! In addition, I'm at a complete loss as to why Polk tech support told me to keep the jumper strips on when the manual states just the opposite. I wonder how many people that are even more ignorant than me about these things (if that's even possible:) have messed up their speakers as a result of trying to follow such a horribly lacking manual?

kawizx9r

No problem!

Wonder who you spoke to when you called up Polk CS (nevermind, don't answer). Plus, we've got an awesome forum here to compensate, not like Polk's CS needs any help....they're among the best I've ever dealt with.

Enjoy those 25's!

-Freddy

PS As for the manual, I haven't actually read one in many years

mantis

Here is the best way to set up the Lsi25's if you plan on using them for music as well.

1) Run speaker wire as well as a LFE RCA line level.
2) Connect both speakers LFE to LFE out of your pre or receiver using a Y adapter or if it as separate outputs use as LFE 1 and LFE 2 out.
3) In your preamp/receiver set the fronts to large
4) Run manual test tone and unplug LFE cables.(Use 75db as your reference point)
5) Bring the sub level up until the speaker is outputting 76 or 77db then dial back until you find a balanced 75db between the top and lower end of the speaker. Repeat on both left and right until the volume is matched. This will give you a tone like if the speakers where non powered. They will be balanced for music.
6) Replug in LFE on both speakers and manual test tone sub out. This will allow you to balance both subs at the same time and with the last settings for stereo remaining , do not adjust the gain on the sub any further , just use the Line level adjustment on the pre/receiver to get your 75db at your listening position.

At this time you also could just run your Mic auto calibration(depending on what you have) to set the LFE and the rest of the levels for theater.

This setup will give you the best experience when using powered towers for both music and movies.

Other setup would be to run the mains in small , remove the jumpers , set each sub up LFE one at a time then plug both in and calibrate together , this setup I can go over in detail if anyone needs it. This is the best for movies and still works good for music.

dorokusai

Nothing will really make those subwoofers sound better in stock form, it's a bad design. The best upgrades are a dB car woofer and treating the port with some sound dampening. As far as cables go and software type tweaks, that's on you.

pmckeealaska

The problem I had using the LFE in was a really annoying hum. Now that I'm using the line in for my subwoofer cables, that problem is solved. I'm pretty happy with how it sounds now. I'm done messing with it I think. The whole experience was a pain in the butt and the manual for the 25's is absolutely awful

mantis

Powered Towers can be a pain to setup if your inexperienced with setups and calibrations but I did find with patience the Lsi25's can sound wonderful.

pmckeealaska

I've calibrated the whole system the point I like it. I'm not going to mess with the LFE in on the subs...just too much of a pain and the hum that was coming off of them annoyed the living hell out of me. I'm happy with how they sound now, which is really all thats important I think!

Thanks to everyone for helping me out on this. You guys are great!!

love2listen

dorokusai wrote: »

Nothing will really make those subwoofers sound better in stock form, it's a bad design. The best upgrades are a dB car woofer and treating the port with some sound dampening. As far as cables go and software type tweaks, that's on you.

I did this mod to my 15's and I must say, it made a noticable difference; Atleast to my ears!

dorokusai

love2listen wrote: »

I did this mod to my 15's and I must say, it made a noticable difference; Atleast to my ears!

Me 2. It's an easy tweak. Good job L2L.

pmckeealaska

Man, I just cant catch a break with this stuff. I decided to switch back to the lfe in on my 25's subwoofer cause the bass is so much better than on the line level in. Now, I have a hum coming out of the subwoofers! It's not super loud but after having none, it is a tad annoying. My subwoofer cables have these extra tails that cab be attached to both the reciever and subwoofer to supposedly take care of the hum but I'll be damned if I can figure out where on either to screw them in. Any ideas? I've done so much tweaking on these damn subwoofers is driving me crazy. I just want to be done with it!

kawizx9r

pmckeealaska wrote: »

Man, I just cant catch a break with this stuff. I decided to switch back to the lfe in on my 25's subwoofer cause the bass is so much better than on the line level in. Now, I have a hum coming out of the subwoofers! It's not super loud but after having none, it is a tad annoying. My subwoofer cables have these extra tails that cab be attached to both the reciever and subwoofer to supposedly take care of the hum but I'll be damned if I can figure out where on either to screw them in. Any ideas? I've done so much tweaking on these damn subwoofers is driving me crazy. I just want to be done with it!

Didn't I tell you it'd be better to utilize the subs that way?

The hum is most likely a ground loop issue. I used to have it on my old powered towers and it went away when I hooked them up to a power conditioner (that was connected to a properly grounded outlet).

pmckeealaska

Yes kawi, you were right!

Actually though and you're probably going to want to kill me for this, I just wasnt getting the right amount of base with the LFE in when I kept those damn jumper strips off....so, I put them back on and like that...instant kick **** bass. Now, I know what I've been told on here about keeping those damn strips off, but it just doesnt sound right without them on. As a matter of fact I've had them on for most of the last 6 years I've had the speakers with no ill effect so I dont know what to say on that score so please feel free to scold me if you want.

In terms of the hum, I already have everything plugged into a Monster Power Center HTS 1000 which is in turn plugged into a Monster AVS 2000 Voltage Stabilizer. I would think the combo would take care of any ground loop issues. Clearly I'm wrong on that score. The hum isnt obnoxious, just kind of noticeable at low volumes. It wasnt there at all when I had the subwoofer cables going into the line level in of the woofers. Thoughts?

kawizx9r

Ground loops could be caused from a number of things. The potential has probably been there for awhile but up until you used your LFE/sub cables you didn't know it was there. I had multiple subwoofers but up until I added my powered towers, I never had a ground loop issue.

pmckeealaska

It is driving me to distraction. I just wish I could figure out where to connect these extra tails on my subwoofer cables. Audioquest says they're designed to take care of just the problem I'm experiencing.