DIY PMC MB2 clone

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#41
Option 6: I have a couple of Hypex PSC2.400 which are available. On the front baffle the WO24 in a sealed subcabinet 37liter containing also the M and T (they are sealed).
The rest of the volume +/- 70 liter for a side firing WO24 powered by the hypex crossed low (80hz) in a bass reflex config.

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+ tweeter at ear height
+ No lobing between the woofers
+ high gross volume 110 liter
+ sealed response
+ more power available due to addition of PSC 2.400
 
#44
Charles Darwin said:
As long as they are high passed ported boxes win on extension, reduced excursion and therefore reduced distortion.
They still lose to sealed on phase, the audibility of which in the low bass registers is still open to debate.
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If you check the group delay of a sealed enclosure it is indeed very low

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but it lacks extension.

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When you eq them flat

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the group delay will also rise significantly.

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So I'm not sure what is best.
 
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#45
Best is what does not need eq to get your desired result.

A boosting eq eats up valuable headroom (amp power, cone excursion, potential power compression...) it should always be the very last resort IMO.
Cutting eq is much less problematic but it is still better to avoid it if possible.


Same goes for room correction. Your listening position might be in a bass null and suddenly 10db or more of boost are applied. You would be much better off rearranging the room so you are out of the null than applying eq in such situations.
 
#46
Charles Darwin said:
Best is what does not need eq to get your desired result.

A boosting eq eats up valuable headroom (amp power, cone excursion, potential power compression...) it should always be the very last resort IMO.
Cutting eq is much less problematic but it is still better to avoid it if possible.


Same goes for room correction. Your listening position might be in a bass null and suddenly 10db or more of boost are applied. You would be much better off rearranging the room so you are out of the null than applying eq in such situations.
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That's true. But our control room has a fixed lay-out so we have to make the best of it 🙂 We can shift the desk backward 15cm or so but this is moving the listening position towards the middle of the room and the bass response degrades. Still pondering on the design... option 1 or 5
 
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#48
In anticipation to the project I built a circle jig for my router.

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The drivers are also delivered. After the weekend I will post some pics.

Can a mod change the topic name in something like "Volt Satori 3-way studio monitor" Or should I start a new topic since I completely deviated from the MB2 clone idea?

The back plate of the speaker will be made of laser engraved stainless steel:

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The WBT look-a-like terminals and banana plugs are allready delivered:

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#49
WalterPPK said:
That's true. But our control room has a fixed lay-out so we have to make the best of it 🙂 We can shift the desk backward 15cm or so but this is moving the listening position towards the middle of the room and the bass response degrades. Still pondering on the design... option 1 or 5
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Maybe something like the attached Focal's rotatable top end baffle could work for you?
 

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#50
I tried to draw up something like the Focal but then the cabinet has to be larger and that complicates things. There is not enough space on each side of the lcd's.

Is the miniDSP openDRC-DA8 in combination with rePhase a good alternative to the (expensive) DEQX? 8-outs would be perfect to do the monitors and the sub.
 
#51
The mids and tweeters are delivered. The magnet of the Volt is so strong that the tweeter can't get near the mid without being pushed away. Does the strong magnetic field affect the tweeter when mounted in the box close to each other ?

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#55
Why leave the TL option? I think that a TL (properly designed) gives a much better low end control than a bass reflex does. This adds to lower distortion, which is one of the reasons people like TL's.
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I agree. I built a PMC TL clone and it sounds super - it needs some care to adjust the stuffing/damping just right so that it doesn't end up sounding like a bass reflex. You can tell it is good when the measured impedance curve has a single wide bump with two smaller peaks on it (vs a BR which has two distinct peaks).

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Mine are currently actively driven by a miniDSP and two channels from a cheap Class D but sounds superb. Very articulate and deep bass for a little 5in driver.
 
#58
The design is ready. Made some minor changes. I put one M5 screw behind the flange of the tweeter to make an invisible connection with the brace. The braces have a cutout in the back to mount the connectionplate from the inside after the box is painted. The cutouts will be filled with a piece of wood afterwards.

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#59
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