DB840 sub in LSI15's replace the stock 8"driver!!!!!

TouchOfEvil

Well i bought a single DB840 sub to try out this swap.
"only bought one in case this was a bust and did not improve the sound/work out."

Important thing to note if you plan to do this at any time you must remove the rubber seal around the DB840 in order for it to fit in the pre fabbed spot for the 8"driver. If you do not it will not fit.
This of course means you need to make your own gasket so get some mortite ready.
I have not done that step yet but will tomorrow.

Also if you plan to do this get new screws the old ones sheer off really easy trying to get the new sub to seal all the way. They are easy to snap like a twig trust me.
On to the speaker/seal, i currently do not have a seal to finish up the job. I will do this tomorrow but i had to listen to what the new driver had to offer even if it didn't have a true perfect seal. It isn't horrid but you can feel a little air leaking out at the moment so i will correct this once i get to the hardware store and get the good stuff.

Overall with the new driver the 15's can handle more volume/power instantly. Most likely due to the power handling of the new unit.
To me the stock unit did not go deep enough was kinda slow about things overall sloppy in general and i had to have a sub going to make me happy with them.
Note that my 15's have upgraded crossovers done by Ben with sonicaps already as well and this is how i feel about the stock bass driver even still.
If pushed to hard the stock sub would reach it's limit bottom out sometimes and always kinda had a resonant sound to it. Just not good.

The GOOD.
The DB840 has a vast improvement in bass reproduction. It is quite a bit faster plays much deeper without going out of control no longer has the same resonant sound the old driver seemed to produce and cleaned up the sloppy sound greatly!!
I am only running one atm because like i said i didn't want two of them in case it did not work out but, even with the single sub i can tell i will not be running a sub for 2 channel any longer.
With the new driver sitting in my chair i could feel the bass beating in my chest and feel the vibrations thru the floor in my feet as if a sub was running.

With two i would imagine the output would be very nice and " I placed an order for the second one before making this thread."
If you feel your 8" driver is your main displeasure in your LSI15's i suggest you try swapping them out with the DB840 single voice coil 4 ohm subs.
The difference is greatly noticed and a massive improvement to my ears.
The subs do not cost alot of money and they will tighten up the bass big time.

Using a test CD to sample bass notes for a hz vs hz comparison stock vs DB sub.
The DB sub was able to reproduce very livable bass down to 40hz and really comes alive 45hz and up with some intense spl for a 8inch driver.
The stock unit was able to reproduce livable bass down to 53hz and had average spl output at around 58hz.
This is of course being nice about livable for the stock unit as it falls short all over the board vs the DB sub. Also note the spl output for the stock is down across the entire board of HZ ranges and it is very noticeable for the entirety of a 120-20hz drop.

Doro told me about this swap so a BIG THANKS goes out to Doro for filling me in on this cost effective very worth while mod!!!!!

McLoki

You have a "The Good" section, but no "The Bad" section.....

Any down side to the swap in your opinion? (other than the annoying gasket and screw issue that you mention).

Congrats on the upgrade. Wish you were closer so I could hear before the swap....

TouchOfEvil

McLoki wrote: »

You have a "The Good" section, but no "The Bad" section.....

Any down side to the swap in your opinion? (other than the annoying gasket and screw issue that you mention).

Congrats on the upgrade. Wish you were closer so I could hear before the swap....

I guess i could have labeled the screw/gasket issue as THE BAD but i didn't think about it honestly.
Really as for performance there is no downside to the swap, it plays lower,deeper,louder,faster,lost the annoying resonant sound. It just really fills in the missing links in the low end for the 15's. I have about 20hours on the sub now "let it play all night" and it outperforms the stock by a huge margin.

If your not sure about the swap i would recommend getting a single sub from ebay like i did. I found it for 59.00 shipped. To me 59.00bucks isn't a big deal and worth the risk. Plus i already know how much better it sounds.:D

TouchOfEvil

Has anyone else gave the DB subs a go yet? Anybody plan too?
Personally i am in love with the 15's now that i have the new drivers in there.:D

Face

I've been leaning on a local Polkie to try this. He already has upgraded crossovers, so this mod would make them even more impressive.

Face

They're ordered.

I hope he doesn't bring them here for the upgrade, my ugly speakers are a little worried.

TouchOfEvil

Face wrote: »

They're ordered.

I hope he doesn't bring them here for the upgrade, my ugly speakers are a little worried.

Lol, well i'm sure they will give some good impressions with the new drivers.
I have not used my sub since i got em swapped out and before i used the sub all the time.

vmaxer

TouchOfEvil wrote: »

Lol, well i'm sure they will give some good impressions with the new drivers.
I have not used my sub since i got em swapped out and before i used the sub all the time.

Have you upgraded both speakers now?? If so, how do they sound and compare?? I still have a set that have no mods at all and am trying to decide if I want to play with them or sell them. I haven't used them much at all due to getting the 1.2tl's shortly after getting the LSi's...

This is tempting.

Face

A modded pair of LSi15's are more coherent and have more resolution than SDA's, but they'll never have the SDA soundstage.

TouchOfEvil

vmaxer wrote: »

Have you upgraded both speakers now?? If so, how do they sound and compare?? I still have a set that have no mods at all and am trying to decide if I want to play with them or sell them. I haven't used them much at all due to getting the 1.2tl's shortly after getting the LSi's...

This is tempting.

Yes, i have had the two drivers replaced for a good while now.I also have them running on a Adcom 555 atm as i got one for a nice price a little while back and wanted to see how it sounds vs the Rotel unit.
The 15's have really come alive compared to stock, everything in the low range is fuller,faster and they can play alot deeper not to mention they are louder as well. To replace both drivers it is not at all expensive once you find em on ebay with free shipping. The cost for this mod is very doable and VERY worth while.

camtah

I noticed that your crossovers were modified. Has anyone done this mod on the stock crossover and noticed a significant improvement? I love my LSi15, but do find the bass a bit "reserved" despite all of my efforts on placement and room treatments. Mind you I am not unhappy. I just want to be it to go to "11"

TouchOfEvil

camtah wrote: »

I noticed that your crossovers were modified. Has anyone done this mod on the stock crossover and noticed a significant improvement? I love my LSi15, but do find the bass a bit "reserved" despite all of my efforts on placement and room treatments. Mind you I am not unhappy. I just want to be it to go to "11"

I'm not sure if anyone has done the mod here. I searched a little and noone really mentioned having done it.
Even if you are using the stock crossovers the new subs will still outperform the stockers. They are just way better subs, so even with a stock crossover you should hear some big changes with the new drivers.

Face

TouchOfEvil wrote: »

I'm not sure if anyone has done the mod here. I searched a little and noone really mentioned having done it.
Even if you are using the stock crossovers the new subs will still outperform the stockers. They are just way better subs, so even with a stock crossover you should hear some big changes with the new drivers.

http://www.polkaudio.com/forums/showthread.php?t=85058

I should be getting my ears on a pair of hot rodded LSi15's with DB woofers soon.

TouchOfEvil

Face wrote: »

http://www.polkaudio.com/forums/showthread.php?t=85058

I should be getting my ears on a pair of hot rodded LSi15's with DB woofers soon.

Sweet, when are the woofers arriving? You should notice a pretty big difference right away. I know i did.:)

Face

I'm not sure, I have to get in touch with the owner.

chamont

Hi there.

I ordered a couple of DB840's the other day. I'm looking around for Mortite, but can't find it. Where would you recommend I look for it? Home Depot, Wal-Mart? Or just online? Thanks... Looking forward to the upgrade.

Face

chamont wrote: »

Hi there.

I ordered a couple of DB840's the other day. I'm looking around for Mortite, but can't find it. Where would you recommend I look for it? Home Depot, Wal-Mart? Or just online? Thanks... Looking forward to the upgrade.

HD or Lowes.

chamont

Ok. So I replaced the drivers this afternoon.

Immediately, I noticed the extra depth on two channel music. That was nice. But it was really tight. I'm pretty sure it's because of the drivers being new. So I'm running music through them today to break 'em in. The extra depth was obvious, but kick drums felt a little too tight. Bass notes extended nicely, but they felt dry. Maybe it's also partly because I'm used to the old sound. I'm sure that will get better in time. On movies, even this early, the new drivers really come to life. Of course, I have a sub along with the LSi15's, but the entire sound felt fuller and more balanced. Also, it has more punch. I'm watching Taken right now (which I've seen before), and I love the sound.

Incidentally, I do NOT have upgraded capacitors. Well, not YET. I ordered Ninja Master networks the other day from Skiing Ninja. I'm really excited for them to get here. But he says it takes up to a couple of months. So I'm not holding my breath.

Also, I never did find Mortite brand anything locally. HD, Lowes, or Ace. I found some "generic" tape caulk. It's a little too thick. When I pull out the drivers to upgrade the networks, I'll cut it in half before reapplying it. It does make a nice seal though, and I really like it.

So, even early on, before the drivers have really broken in yet, I'd say this upgrade is a no-brainer.

TouchOfEvil

I'm glad you are enjoying the upgrade. I did let the driver break in a bit before i really gave it a listen, then when i got the second one in i let them both play for a couple days before i listened again.
In the end i'd say they are finally broken in after a good 100hours on them give or take a few hours.
At this point i do not use my sub for music anymore. I run it for HT and HT alone now. I simply don't need the extra bump as i get plenty with the new drivers.:cool:

On the mortite i tried HD and they didn't have a clue as to what i was talking about. I ended up going to a local mom and pop hardware/automotive store and they had it. Maybe try small hardware stores in your area.

TouchOfEvil

I also got a pair of the PNF symphony cables and have let them break in all weekend. Before i was running DH Labs Q-10 cables.
The bass a bit heavier than before so much that i thought i had the sub on and had to look for the little blue light a couple times.
The mids seem more forward and controlled. The highs are not as bright though and seem to be a little bottled up so to speak.
So to remedy this i am using my DH Labs Q-10 jumpers, running the PNF to the mids/bass and the DH Labs jump to the highs. This little bit of wire changed the highs by a large margin. They are not AS bright as before but have a nice sparkle to them and they are no longer bottled up sounding. To me i am loving the setup with the new cables while using my old jumpers.:)


BTW:Face have you swapped out the drivers on your friends 15's yet? Impressions?

PSOVLSK

FYI: Crutchfield has these buy one get one 1/2 price. Total is about $120 plus shipping. Maybe not the best price, but my experience with Crutchfield has been positive. They also have them "open box" for about $110. I'm very tempted to pull the trigger on this upgrade.

TouchOfEvil

PSOVLSK wrote: »

FYI: Crutchfield has these buy one get one 1/2 price. Total is about $120 plus shipping. Maybe not the best price, but my experience with Crutchfield has been positive. They also have them "open box" for about $110. I'm very tempted to pull the trigger on this upgrade.

That is a good price. Best i found on ebay was 59.00 each shipped. With Crutchfield you would have a little more peace of mind for the same price IMO.

McLoki

Do you think you would notice much difference in movies even with an 80hz crossover? (or would it not be worthwhile with a crossover set that high?)

TouchOfEvil

McLoki wrote: »

Do you think you would notice much difference in movies even with an 80hz crossover? (or would it not be worthwhile with a crossover set that high?)

Really not sure, you might get some double bass with it that high.

xcapri79 wrote: »

I did this crossover a couple of weeks ago and was not immediately impressed either way.
More time is needed to let the new woofers break in.

After the conversion, my SPL actually showed a -3dB drop measured several times compared with some base line measurements I previously made.
This was based on listening to some ZZ-Top and not on test tones so it wasn't particularly scientific.
I'm interested in knowing whether others made some measurements.

I didn't use a spl meter when testing mine. I used my ears instead, it was a big enough jump to cause some excessive rattle in my room with the new drivers that i had to fix as it was annoying. I never had the rattle before.
It was also very apparent to my GF who could careless about my stereo gear but she instantly said "What did you do?"
I ask what you do you mean and her response was it has so much more bass now, is the sub on?
Of course my response was no the sub is off but i replaced the woofers in the lsi15's, then she rolled her eyes at me lol.

What amp are you using to push the 15's? Also you might want to play with placement. After a few days i ended up moving mine away from the side walls about a half foot to get the sound how i like it.

Face

xcapri79 wrote: »

After the conversion, my SPL actually showed a -3dB drop measured several times compared with some base line measurements I previously made.
This was based on listening to some ZZ-Top and not on test tones so it wasn't particularly scientific.
I'm interested in knowing whether others made some measurements.

That's a pretty poor testing method. You know, room EQ Wizard is free right?

PSOVLSK

I remembered I had a $50 gift card from Crutchfield, so that made my decision pretty easy. Less than $70 shipped for 2 subs:D:D

TouchOfEvil

PSOVLSK wrote: »

I remembered I had a $50 gift card from Crutchfield, so that made my decision pretty easy. Less than $70 shipped for 2 subs:D:D

nice.:cool:

chamont

PSOVLSK wrote: »

I remembered I had a $50 gift card from Crutchfield, so that made my decision pretty easy. Less than $70 shipped for 2 subs:D:D

Excellent! Let us know what you think once you get them installed.

PSOVLSK

TouchOfEvil wrote: »

Important thing to note if you plan to do this at any time you must remove the rubber seal around the DB840 in order for it to fit in the pre fabbed spot for the 8"driver. If you do not it will not fit.

I got mine in on Monday and hooked them up, but I must have done something wrong. I forgot about removing the rubber gasket, but it stills seems to fit just fine. I moved my hand all around each driver and I don't seem to be losing any air. Should I just leave well enough alone, or should I go back in and remove the rubber seal and make my own gasket? Also, did you guys use screw in every hole in the new driver or just use the screw you took out of the old driver?

Haven't had a chance to break it in and really crank it up, but the bass at lower volume levels does seem to be improved. Maybe it's just that way because it's what I want to hear, but it does seem tighter and deeper.

Thanks for your help guys. I'm hopeful that this will be one of my best and least expensive mods.

chamont

I'm surprised you even got it in the cabinet with that thick piece of rubber around the speaker. It's probably fine as-is. Personally, I'd take the rubber thing off.

I just used the existing four screw holes in the cabinet, and left the other four on the woofer empty. Using all eight seemed total overkill.

TouchOfEvil

PSOVLSK wrote: »

I got mine in on Monday and hooked them up, but I must have done something wrong. I forgot about removing the rubber gasket, but it stills seems to fit just fine. I moved my hand all around each driver and I don't seem to be losing any air. Should I just leave well enough alone, or should I go back in and remove the rubber seal and make my own gasket? Also, did you guys use screw in every hole in the new driver or just use the screw you took out of the old driver?

Haven't had a chance to break it in and really crank it up, but the bass at lower volume levels does seem to be improved. Maybe it's just that way because it's what I want to hear, but it does seem tighter and deeper.

Thanks for your help guys. I'm hopeful that this will be one of my best and least expensive mods.

If it's not leaking any air i'd leave it alone. I couldn't even get mine to setup with the rubber seal, guess your better at this stuff than i am lol.
Anyway i used 8 screws simply because i had them. If your not leaking any air then i see no reason to worry about it as the 4 screws should do the job.