Improving the Lsi9, from 500hz to 2khz

polkseller

I saw a review on Stereophile and soundstage website and it seems that the lsi 9 had problem between 500hz and 2k. It had lots of peaks and highter distortion.

Is it crossover related or cabinet resonant problem?

Does adding dynamat inside help solve this problem ?

heiney9

So are you hearing this peak and distortion................or is it what was printed on paper? Printed specs don;t mean much........how do they sound? Before you read the reviews were you noticing this? I wouldn't worry about it. Proper set-up, room treatments and the right gear will make them sound great.

H9

candyliquor35m

I don't know if anyone here has heard of this. Maybe you could post some links to the reviews or scan and post them.

jakelm

I would replace all drivers, rebuild crossovers and build new cabinets. If there is a problem...


but thats just me.....

jakelm

http://www.stereophile.com/budgetcomponents/795/index4.html

Maybe this??^^^^^

dorokusai

Where are these reviews exactly? The formal 2002 LSi9 review by Soundstage was very postive and has no mention of this anomaly.

Systems

jakelm wrote: »

I would replace all drivers, rebuild crossovers and build new cabinets. If there is a problem...


but thats just me.....

OK wise guy, what if you go through all that effort to build new cabinets etc. only to find that the problem is still there.:eek:Then what do you do?

jakelm

The review on the lsi7 says alittle about this. But nothing but praise for the overall speaker.

jakelm

GV#27 wrote: »

OK wise guy, what if you go through all that effort to build new cabinets etc. only to find that the problem is still there.:eek:Then what do you do?

I mail them to you to figure it out...


...you know,,what freinds do for each other...:D

dorokusai

jakelm wrote: »

http://www.stereophile.com/budgetcomponents/795/index4.html

Maybe this??^^^^^

That review is about an LSi7. It touches on some cabinet coloration at a specific frequency but this is not unusual for a loudspeaker.

Systems

jakelm wrote: »

I mail them to you to figure it out...


...you know,,what freinds do for each other...:D

Thanks, I need more fire wood because this winter has been a long and cold one.

jakelm

GV#27 wrote: »

Thanks, I need more fire wood because this winter has been a long and cold one.

You need fire wood? I'll just send you these. Have fun...:p

Systems

jakelm wrote: »

You need fire wood? I'll just send you these. Have fun...:p

OMFG
I can't believe I just saw that.:eek:

Mazeroth

I have a measurement setup in my basement and actually measured an LSi9 a few months ago. I didn't notice anything abnormal in the 500-2k region and the distortion looked very good.

polkseller

yes guys this is the stereophile review I'm talking about. And this is the one from soundstage: look at the frequency graph 500hz to 1200hz

http://www.soundstage.com/revequip/polk_lsi9.htm

You can clearly see distortion between 50hz and 200hz and also in the mid 1000hz ( chart 3)

I was wondering if it was the in-room response that was bad in this region because many tested speakers behaved like that in between 500hz to 2khz on the stereophile website...also the high frequency extend to 20k without roll-off on the soundstage graph, not the case on the stereophile graph.

I dont know if this 1k resonance is a problem, maybe at loud volume or with constant note at that frequency. I would like to know if the new polk rti A7 with round cabinet are better on this matter.

overall the lsi 9 has good frequency response except for its boomy bass and highter than normal distortion at 80hz @ 90db.

The post says: improving the lsi 9. I read that some polkers add some dynamat extrem to their lsi9 to reduce resonant frequency. any ideas to improve the woofer under 200hz ? Does any of you tried foaming the lower port or modify the rear powerport ?

dorokusai

I'd use Black Hole instead of Dynamat but this issue should be addressed in your listening room with sweeps, not tweaked based on NRCC chamber response. Good luck but it's much ado about nothing.

Again, it's never discussed as a "problem" in the Soundstage review....it's just a measurement graph.

PolkThug

Don't worry about the distortion stuff, its less than some of Wilson Audio's stuff, but more distortion than Paradigm's Reference speakers.

If the primary tone is at 95db for a fraction of a second and the distortion is at 60db for that same time frame, will you hear the distortion? Probably not. You could train yourself to hear it with a sustained tone, but that probably isn't very high on the fun factor.

polkseller

will adding dynamat will improve the 50-200hz region and reduce distortion ?

I think yes.. 60db seems high, more than my dishwasher :rolleyes:

jakelm

polkseller wrote: »

will adding dynamat will improve the 50-200hz region and reduce distortion ?

I think yes.. 60db seems high, more than my dishwasher :rolleyes:

60dB's is almost a whisper. I calibrate all the time. I can make my needle set at 60dB's, move with only a whisper. And this happens at a fraction of a second?? I doubt any of us could spot it.

But it is your opinion. I respect that.

Take a SPL meter, put it on 60dB's and test it yourself, you will see what we are talking about.

PolkThug

polkseller wrote: »

will adding dynamat will improve the 50-200hz region and reduce distortion ?

Only if the 'distortion' is the resonating of the enclosure.

polkseller

ok thanks guys!

Anyway, I saw many other speakers on the market with this kind of distortion under 200hz.

dorokusai

Really? No way!

jakelm

dorokusai wrote: »

Really? No way!

Polk exclusive...:rolleyes: