"It sounds muffled...", Please help

[Champster]

I would appreciate your comments/thoughts to resolve this issue with the woofers in my system.

First a little information. I am running a miniDSP 4x10hd all slopes are 24db/oct with a 2206 in a 2cf sealed cabinet crossed over to a 2123 at 300hz. The 2123 is in a .6cf sealed cabinet. Both cabinets are filled (not stuffed) with unbacked fiberglass. The 2123 goes up to 1200hz and hands it over to a 2446Be. I have double checked the polarity connections and confirmed that all + cable are going to the black terminal.

The bass sound muffled all of the time, but when I turn off the horn and run just the 2206 and 2123 it is not clear if it is the 2206 or the 2123. This occurs on all of the recordings I play whether they are small acoustic groups, classical, jazz or rock.

I'm not sure what adjustments I can make to improve the resolution.

Anyone have any suggestions?

I should note, I am comparing these to my Linkwitz LX521's.



Thanks Guys!

[macaroonie]

the 2206 is ' modern' phase ie + is the red terminal.
Can't vouch for the 2123
Your subs should have shorting links put in if you are not using them otherwise they will behave as bass traps.

[Lee in Montreal]

Hi Champster

Seeing you have a calibrating mike, why don't you measure each driver individually. Then compare each curve. It could tell you each driver's range and level. The you could modify accordingly, using your crossover.

Lee

[Champster]

the 2206 is ' modern' phase ie + is the red terminal.
Can't vouch for the 2123
Your subs should have shorting links put in if you are not using them otherwise they will behave as bass traps.

Regarding the 2206. The Data sheet I have shows the black terminal as forward cone movement??? This wouldn't be the first time there is an error in a data sheet however...

[Mike Caldwell]

The 2206 is still the "old school" JBL polarity. Positive on red moves the cone backward.

[greg32]

I use the 2206 up to 1200hz in a 2cf reflex alignment, I fined the bass is not overly strong but nice down to about 50, in a sealed alignment the roll off would be more gradual but starting earlier. I have tried to include a screen shot of winisd plotting both 2cf sealed and 2cf ported tuned to 60hz. you could also try adding eq to the bottom end to counteract the roll off. do some measurements of just the individual drivers to confirm there response. Greg

[Champster]

Hi Champster

Seeing you have a calibrating mike, why don't you measure each driver individually. Then compare each curve. It could tell you each driver's range and level. The you could modify accordingly, using your crossover.

Lee

I use the 2206 up to 1200hz in a 2cf reflex alignment, I fined the bass is not overly strong but nice down to about 50, in a sealed alignment the roll off would be more gradual but starting earlier. I have tried to include a screen shot of winisd plotting both 2cf sealed and 2cf ported tuned to 60hz. you could also try adding eq to the bottom end to counteract the roll off. do some measurements of just the individual drivers to confirm there response. Greg

Hello Lee and Greg,
My issue isn't bass extension, it it more coherence. I do believe it is the 2206 however that is causing it and I don't know how to measure that quality in a driver/system. It measure flat to 50 hz with some boost from the PEQ and is flat in amplitude in comparison to the 2123. I'm stuck and don't know what to do to fine tune it further.
Thanks,
Paul

[audiomagnate]

Hello Lee and Greg,
My issue isn't bass extension, it it more coherence. I do believe it is the 2206 however that is causing it and I don't know how to measure that quality in a driver/system. It measure flat to 50 hz with some boost from the PEQ and is flat in amplitude in comparison to the 2123. I'm stuck and don't know what to do to fine tune it further.
Thanks,
Paul

I don't know what you mean by "coherence." Coherence has to be between two things. A woofer by itself can't have coherence. Are you talking about phase coherence between the the subs and the mains?

[Champster]

I don't know what you mean by "coherence." Coherence has to be between two things. A woofer by itself can't have coherence. Are you talking about phase coherence between the the subs and the mains?

Agreed. Thank you for the replies and sorry for the confusion. I was referring to the coherence between the 2206 and 2123. The 2123 sounds, and blends wonderfully, with the 2446Be, but the whole system seems to break down and lack coherence in the bass. Also, I'm not using (and therefore not commenting on) the 2245's in the picture. I have them connected to an idle amp so they don't have any effect.

[Mike Caldwell]

Try flipping the polarity of either the 2123 or 2206 and give it a listen.

Are you just going by your measurement data as to what looks like
should sound good or are you tuning the system EQ by ear to make
it sound good as in trying to make it sound good/like you want it to sound.

[Champster]

We'll, I'm not sure what else I can do here. I'll probably get flamed for this but it is what I found. So flame on if you must...

I checked to make sure the black wire (+) resulted in a forward movement of the cone and it did. I swapped out the 2206 for 3 other 2206's I have on hand. I've adjusted the stuffing to both extremes (from none to fully stuffed) and then settled with a modest amount. I measured for in-room response problems, thinking I could adjust any aberrations with the PEQ in the miniDSP for anything within 1 octave either side of the 50-300hz desired range that seemed problematic. I even used the Dirac miniDSP to attempt correction just to make sure I wasn't missing anything. In the end, the PEQ corrections we're very minimal. I'm just thinking that my comparison to the (open baffle LX521) 10" and 8" woofers is not fair. After all, the Seas drivers are a relatively new design and designed for a different purpose than the 2206. In addition, the LX521 was designed by Mr. Linkwitz, one of the most significant contributors in audio engineering history. The guy really knows his stuff. Even though they don't put out nearly as much sound, even at high volumes, the Seas system sounds more natural, and as Mr Linkwitz describes in his design notes, it is "designed for neutral timbre." The 2206 is really very good and very close, but I just can't seem to figure out how to get it to the same level of articulation as the Seas drivers.

I wonder if a ported cabinet would better????

[gasfan]

If your issue is with resolution/articulation, then it's about the 2123. It's the one producing all the leading-edge transients. Me thinks.

btw, why do I see what appears to be reflections off the drivers in one of your pics?? weird

[Champster]

If your issue is with resolution/articulation, then it's about the 2123. It's the one producing all the leading-edge transients. Me thinks.

btw, why do I see what appears to be reflections off the drivers in one of your pics?? weird

It very well could be that too because they are both sealed cabinets. And it could be that I am just spoiled by the sound of a cabinetless design???

One of the pictures shows inside the cabinet (before I installed the drivers) where I used fat mat to line the walls of each cabinet with to minimize resonances.
thanks
Paul

[badman]

It very well could be that too because they are both sealed cabinets. And it could be that I am just spoiled by the sound of a cabinetless design???

One of the pictures shows inside the cabinet (before I installed the drivers) where I used fat mat to line the walls of each cabinet with to minimize resonances.
thanks
Paul

It's entirely likely that you're accustomed to the sound of the dipoles, which do tend to be perceived as more "live" sounding.

[Odd]

Experiments with more fiberglass in the 2123 box.
It changes the sound quite a lot.