new main speakers

skipf

Greeting all,
I'm new to the club and would appreciate some advice on a pair of new main speakers. I'm considering Lsi25's and wonder if they will have sufficient bass response to satisfy my need to feel the bass. I currently have Lsi9's powered by a Carver PM-300 (150WPC into 4 ohms) controled by a Carver C-1 preamp. The 9's are great from mid to high range, but pretty soft on the bass. I have a Carver M500t on the way which I think is 500 WPC into 4ohms. I'll run the front mains off of the M-500t and the rear off the PM-300. I do have two PM-300's. Would it be beneficial to bi-amp the 9's with the PM-300's? Are the old monitor series better for bass response than the 25's? Any other brands (I know this is heresy on a Polk forum) in the 25's price range that would be better? Thanks for any advice you can offer.

sickicw

you have a few options. First, you could get another 20 hz of bass with the 9s if you had a higher current amp (im thinking a krell, high end earthquake, or sunfire). Second, the lsi15 will also give you a bit more bass (i wouldnt get the 25s). Third, if you added a good subwoofer that could blend in with your 9s you will get more bass. Any one (or combination of) thoes would work to give you more bass.

venomclan

Welcome Skip,
Adding more powerful amps will tighten up the bass and help the speakers reach their full potential, but no amp will make the 9's go "lower" than they were designed to go. The drivers can only travel, pressurize and displace so much air as was intended. Speakers are rated as to what hz they can reach, anything beyond will cause distortion/rupture.

Larger fronts will help with the bass, but if you are really a bass-head, only a sub/subs will provide what you are looking for.
Venom

McLoki

Keep the 9's and add an SVS Ultra sub. (should be able to pick one up on the used market once the new Ultras come out in may)

You will not be able to amp yourself into more bass out of a bookshelf speaker. Better defined and maybe a tad louder (overall), but no deeper.

The 15's are nice (never really cared for the 25's, but to each their own) but I would stay with the 9's and add a nice sub. (or get the 15's and add a nice sub - either way would work)

Good luck,

Michael

sickicw

McLoki wrote:

You will not be able to amp yourself into more bass out of a bookshelf speaker. Better defined and maybe a tad louder (overall), but no deeper.

That is just wrong. I have done testing myself. Using an outlaw amp, my lsi9s and a radio shack meter, the 3db rolloff of bass is around 80hz. Using my rockford amp, the rolloff is below 60hz.

Also this simulation confirms my test...

http://www.polkaudio.com/forums/showthread.php?t=50298


EDIT: As i side note, adding a sub is usually the easiest way to get more bass
.

McLoki

sickicw wrote:

That is just wrong. I have done testing myself. Using an outlaw amp, my lsi9s and a radio shack meter, the 3db rolloff of bass is around 80hz. Using my rockford amp, the rolloff is below 60hz.

I have never heard of anyone having an LSi9 roll off at 80hz nomatter what amp they were using unless they had the speaker set to small and configured the rolloff for 80hz. Is it possible you did an auto-setup on your avr and after you added the amp it moved your crossover to 60 hz (or set your speaker to large)? (the auto setup prior to adding your amp maybe set the crossover to 80hz?)

If you run an LSi9 set to large, it will produce bass at least into the mid 50's running off near any avr. The bass it produces may not seem very accurate and the avr may go into thermal protection - but the bass will be there.

Michael

sickicw

Even the soundstage test of the lsi9 showed the rolloff to start at 90hz...

http://www.soundstagemagazine.com/measurements/polkaudio_lsi9/

...it doesnt really say what amp they are using...

McLoki

From Polks site:

Electrical
Overall Frequency Response 38Hz - 27kHz
Lower -3dB Limit 50Hz
Upper -3dB Limit 26kHz

from the soundstage review:

Polk says the LSi9 has a -3dB low-frequency point of 50Hz -- realistic with some careful setup. Nevertheless, what this figure doesn’t tell you is how much impact these speakers have down low. The LSi9 is capable of wallop on the bottom end that is very impressive.

sickicw

I couldnt agree more. The lsi9s have great bass, but with some careful setup. Also notice the 90hz hump, right before the rolloff.

tonyb

Bottom line....keep the 9's and get a sub,you won't be sorry.

Schwingding

Try a pair of these maybe - the response is remarkably flat down to 40Hz. They have a built in powered woofer - the effects of which can be seen between the two lines. Plus, they're $1000 less and get far more rave review. With mine calibrated properly, there is still at least 1/2 the gain control left for more bass, which I do employ sometimes when "rocking out", but normally there is more than adequate power for bass drops.

skipf

Thanks to all for the advice. Seems like a good sub is the way to go. I'll proceed in that direction. Do I need a processor with a sub output or can I use the second set of outputs on my pre-amp to connect the sub? Is there a way to reduce the bass signal to the Lsi-9's to put more power to the mids and allow the sub to handle all of the bass?

sickicw

does your pre-amp have a sub out connection? You can crossover your lsi9 at a higher frequency (80hz or higher) to put more bass to the sub if your pre-amp does bass management.