Step-Down Mode on EV TL15-2

[Robert Healey]

Hello everyone,

I just bought three EV TL15-2s to use as subwoofers for a great price. They shouldn't get pounded, so I'm not too worried about the finish and I like the idea of them being only 108 lbs - with casters, handles, and covers added I should be able to set them up by myself.

Has anyone successfully used the step down mode on these speakers (or other EV TL series)? The EDS says that it'll lower the -3dB to 33 Hz if the right EQ is used. Will it significantly reduce output or change the sound quality?

The EDS states:

The suggested equalization is an underdamped second-order high pass filter tuned to 29 Hz with a Q of 2. This provides a boost of 6 dB at the tuning frequency and a 12-dB-per-octave roll-off below.

I eventually plan to use an EV DX46 processor for these and the Xi-1122 mid/high speakers, but right now all I have is the DSP in the XTI amplifiers. I'm not sure how to translate that EQ setting into an XTi DSP setting. I might try to get a used XEQ-2, since it seems like it has some pretty sophisticated analog processing.

The manual doesn't say how many of the ports should be blocked, either, and I don't have the original port covers. Any suggestions on what to use?

Thanks,
Robert

 

[David Ionita]

Hey Rob, did you ever figure this out? I'm trying to activate the same step-down mode in my TL15-2.

 

[Scarlett Rose]

I have 6 TL 18" boxes(had 8 till I let a "freind" borrow a pair and they stole um). With the old 18B yea it seemed to reduce output in the step down mode.
Mine are currently empty waiting on being reloaded with better drivers. As I calculated to retune them, the best thing to do was block the outter two sections of the port and use and extend the center section(the part EV blocks for 33Hz tuning)

 

[Art Welter]

Hey Rob, did you ever figure this out? I'm trying to activate the same step-down mode in my TL15-2.

The TL-15 is already over -8dB at it's tuning frequency (Fb) of 40Hz.
Covering ports to drop the tuning to 28Hz will drop the response about another -6dB , requiring four times the power to compensate.

If you are using the cabinets for anything other than a home stereo, the additional boost required for anything near flat response will make the speakers run out of excursion 1/3 octave up from Fb.

As well as that, covering ports increases "port compression", the air will literally be blown out of them at high drive levels, no longer functioning at Fb.

Upgrading speakers would require much larger and longer ports to avoid port compression.