Need help with a xover please...

Status
This old topic is closed. If you want to reopen this topic, contact a moderator using the "Report Post" button.
It's kinda tragic that most of the British sound has been outsourced to China. :(

I do remember having a look at some Tangent stuff. The fact is the drivers have come a long way since bextrene bass and the T27 mylar tweeter. But I want to try a mylar tweeter soon.

Metal and ceramic domes do seem to work best with a soft surround to tame the HF resonance. Joachim Gerhard and Harbeth favour this SEAS 22 TAF/G with some mods to the phase plate in their "cheaper" models. AFAIK, Harbeth use a SEAS Excel tweeter in their best models.
 
The SEAS Excel stuff is different...I've heard them as well...a buddy has had many drivers in that line...he is pretty now all switched over to Accuton...dare I say "ceramic"?? LOL!!

But ya...the Excel drivers are nice...nicer than the Prestige for sure...they sound more alive!!

Another question while I have you here...any suggestions on components for the xover?? I just used some standard stuff from Madisound...

The Madisound Speaker Store

The Madisound Speaker Store

The Madisound Speaker Store
 
Lynn Olson is of the opinion that a low DC resistance on the tweeter coil is a good thing to reduce IM distortion arising from low frequencies getting through. Otherwise, it is questionable if you need to spend huge amounts on crossover components.

Alan Shaw of Harbeth is happy with wirewounds and smallish polyesters (MKT) on his top model. He also thinks that removeable panels are a GOOD THING! :D
 

Attachments

  • Harbeth_Monitor_40.1_Part of Crossover.JPG
    Harbeth_Monitor_40.1_Part of Crossover.JPG
    76.8 KB · Views: 126
Update:

A couple of weeks ago I added the caps as shown in the 2nd version of the xover...put the tweeter back into phase with the woofer...much added improvement!!

Steve...been enjoying this build greatly!!!

Not sure if there is any more tweaks but give yourself a pat on the back...your xover was fab :D
 

Attachments

  • IMG_3627.jpg
    IMG_3627.jpg
    297.4 KB · Views: 85
  • Morel_Trial_3rdOrder.PNG
    Morel_Trial_3rdOrder.PNG
    10.9 KB · Views: 90
  • Morel_Trial_3rdOrder_FR.PNG
    Morel_Trial_3rdOrder_FR.PNG
    20.7 KB · Views: 82
  • Morel_Trial_3rdOrder_Phase.PNG
    Morel_Trial_3rdOrder_Phase.PNG
    19.3 KB · Views: 83
Thankyou, sideways (Dave)...:D

It wasn't rocket science. :eek:

Lynn Olson is my guide:

When working with rigid-cone drivers, there are some hard choices to make: if you lower the crossover frequency to minimize driver coloration, tweeter IM distortion skyrockets, resulting in raspy, distorted high frequencies at mid-to-high listening levels.

If you raise the crossover frequency to improve the sound of the tweeter, the rigid-driver breakup creeps in, resulting in a forward, aggressive sound at moderate listening levels, and complete breakup at high levels. (Unlike paper cones, Kevlar, metal, and carbon fibers do not go into gradual breakup.)

With the drivers we have today, the best all-around compromise is a 2nd, 3rd, or 4th-order (12-24dB/Oct.) crossover with an additional NOTCH filter tuned to remove the most significant HF resonance of the midbass driver.

It MIGHT be worth trying a 7kHz tank/notch on the Morel HU_621 6" bass driver to straighten out the phase. After that, I'm out of ideas. THIS IS AS GOOD AS IT GETS. That is, until NFL kicks off again. :)
 

Attachments

  • Sideways_Tank_7kHz.PNG
    Sideways_Tank_7kHz.PNG
    8.4 KB · Views: 39
  • Morel_HU621.jpg
    Morel_HU621.jpg
    69.6 KB · Views: 44
Just another Moderator
Joined 2003
Paid Member
Also have a look at the CAT378 :) http://www.parts-express.com/pedocs/specs/277-084-morel-cat-378-specifications.pdf

I've got the pre-decessor DMS-37 and I'm really happy with it. Mated with a pair of MW-144's so yes a total morel 2 way :)

The best thing about it (with the MW-144's) is that with the tweeter flush mounted and the woofers surface mounted the two drivers are time aligned. No fancy baffle work required ;) Wouldn't quite work with the woofers you have, but it would be a lot closer to time aligned than with the CAT-298.

Advantages of the 378 IMO

Higher sensitivity (probably not an advantage in your case).
Higher power handling.
Smaller face plate (allowing closer mounting to the other driver)
Potential for easier time alignment.
Lower resonant freq (for potentially lower crossover point). Though I wouldn't go low without a steep crossover.

Tony.
 
Status
This old topic is closed. If you want to reopen this topic, contact a moderator using the "Report Post" button.