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Cornwall III - early bass rolloff? Solved!!


Ziggurat

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If you have essentially no output below 60Hz, don't bother worrying about the source, pre-amp or amplifier. Even pain old, low cost equipment will have output at least an octave below 60 Hz. 

 

Your problem is obviously elsewhere. Again, give your dealer (since you purchased these new) a call. They will sort it out for you. Just be very clear about what you mean by "no output below 60Hz"

 

However, if the symptom is that there is "less than expected output below 60Hz", then that is a different symptom. BTW, where did you get the number 60Hz? Did you use a test signal of some sort, or was this a guess?

 

Good luck,

-Tom

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 Not to insult you Ziggurat, but to possibly help others, woofer polarity can be confirmed without opening them up (which I would hesitate to do to speakers recently purchased new from an authorized dealer).

 

Using a AA battery, the movement of the woofer cones can be observed.  If they both move out when the battery polarity is identical, and in when the polarity is reversed, the woofers are in phase with each other.

 

I look forward to hearing about your solution.

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So you tried pairs  and each exhibited  the same problem? . Are they close to each other in terms of production sequence? Perhaps a bad batch of crossovers were installed in the speakers and a regrettable laps in quality control failed to catch both pairs. As suggested I would ask the dealer to come out and take a look  and to bring proper measuring equipment/instruments .

 

My CWIIIs also extend down into the 30s  with little change in output. 

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9 minutes ago, ODS123 said:

Perhaps a bad batch of crossovers were installed in the speakers and a regrettable lapsE in quality control failed to catch both pairs.

HIGHLY doubt that.  Run the woofers in a bit first if you are certain they are in phase.  I dont think I would result to bass traps to solve this issue just yet... Rarely do I listen at very low volumes, but perhaps you do and need to get the woofers suspension used to moving first (perhaps a bit stiff new) .... 

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Been watching this and hard to imagine no bass below 60, definitely not what I am hearing here. If the wiring is correct and not out of phase I bet it's the room canceling out the rest of the bass. Nothing else mechanical like electronics or crossovers, just an affect from the room. 

 

I say this because if anything most people say the Cornwall in any version can almost have to much bass in some rooms. And it's pretty common in some shaped room to have some kind of cancellation or the opposite.

 

We have had our Cornwall lll's in the living room which is 24' wide and 18' deep with NO bass shortage problems, then they were moved into the bedroom 10'deep by 16' wide, the speakers are on the long wall in the corners. No bass problems at all, if anything maby to much bass in the bedroom.

 

Good luck, I'm not really sure what you can do to fix a cancellation ?

 

Possibly temporally move them to a different shaped room or outside for a test, maby even just one speaker ? Any electronics should make them produce good bass below 60hz.

 

For people that know ? Could just disconnecting one speaker wire and play only one speaker reduce the chances of bass canceling itself out ?

 

Hope you figure it out.

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5 hours ago, DizRotus said:

Using a AA battery, the movement of the woofer cones can be observed.  If they both move out when the battery polarity is identical, and in when the polarity is reversed, the woofers are in phase with each other

 

If the wires are long enough and the speakers "mobile" enough, merely placing them closely together front-to-front while "speaking," and swapping polarity of one lead set will give ample indication of woofer polarity symmetry.

 

3 hours ago, dtel said:

Good luck, I'm not really sure what you can do to fix a cancellation ?

 

After that, you provided a couple workable ideas. 

 

I'd add "try asymmetrical room / speaker placement and see what happens."

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Thanks all for the responses.

 

Is pretty clear that we have an unusual room-related issue.  

 

I feel pretty reassured by all comments here that once we get this sorted,  the Cornwalls will be awesome. 

 

Let's leave it there, with my thanks, until I can report back with good news.

 

Cheers.

 

 

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Well, after months of trying different things, tonight I heard Cornwalls the way I am sure they were intended to sound - spectacular!

 

My friend 'acoustically divided' his room - for want of a better term. He hung some heavy drop-sheets half way across the room, set up a table tennis table behind this (in the new 'area' without the soundsystem in it) and moved his sofa closer to the Cornwalls.

 

Suddenly, we have bass! I was measuring right down to 32hz no problem. Really impressive. The lift in the whole presentation is significant.  I sat and just enjoyed everything we listened to for the first time.  

 

My mate seems pretty content - and I can see why. A good result. 

 

Thanks for your help and comments here - they've helped confirm we needed to work on the room harder. Cheers!

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Glad you got to hear them doing what they can do. Now you see why everyone was saying something was wrong, also got proof of how sound waves can cancel out each other. I agree it sounds like a very odd thing but it really happens, kind of hard to believe they can cancel each other almost completely.   

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On 8/25/2019 at 3:02 AM, Ziggurat said:

Well, after months of trying different things, tonight I heard Cornwalls the way I am sure they were intended to sound - spectacular!

 

My friend 'acoustically divided' his room - for want of a better term. He hung some heavy drop-sheets half way across the room, set up a table tennis table behind this (in the new 'area' without the soundsystem in it) and moved his sofa closer to the Cornwalls.

 

Suddenly, we have bass! I was measuring right down to 32hz no problem. Really impressive. The lift in the whole presentation is significant.  I sat and just enjoyed everything we listened to for the first time.  

 

My mate seems pretty content - and I can see why. A good result. 

 

Thanks for your help and comments here - they've helped confirm we needed to work on the room harder. Cheers!

Hi, I have Cornwalls that I can’t get below 45hz measured. Can you explain your room treatments in a little more detail? And if you’ve made changes in the past year? Thanks 

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