WoofT height?

[mudchute]

Here they are:

High Performance Line-level Active 2-way Crossover Filter OPA2134 BUILT/TESTED | eBay

 

[planet10]

2md order op-amps. Good Op-amps, you will need a very goodPS. May not sound as good as a much simplier PLLXO.

Advantages are no dependance on what your amps input impedance is, and leaves more versatility in drivers & placement.

Without being able to play around, i would set them to 120 Hz and take advantage of the higher order.

They are missing level controls (usually one of the reasons for the 1st or last op-amp stage). You will need attenuators on at least one of the power amps (as you would with a PLLXO)

dave

 

[mudchute]

Ah good, so not too bad choice then which is comforting.

Is the attenuator to adjust the power output of an amp to bring them both inline?

 

[planet10]

Is the attenuator to adjust the power output of an amp to bring them both inline?

Yes.

dave

 

[mudchute]

Ok cool.

I apologise for all the newbie questions. I've jumped in at the deep end with diy hifi and my eagerness often overtakes my knowledge. Your help is very appreciated!

 

[planet10]

 

[mudchute]

Due to cost I've been looking at the silver flute w14 or sb acoustic sb15-nrxc30-8.

SB Acoustics SB15NRXC30-8 Midwoofer

The Madisound Speaker Store

Xmas has put a squeeze on what I'm able (given permission) to spend. Both are available for very little.

Is front mounting appropriate for these?

I've been thinking about stuffing too. Whether lining the boxes, stuffing or a combo of the two. I guess if I make the back panel a screw on affair then I can experiment.

Lastly, have you a suggedtion for vent dimensions?

Thanks again for your help

 

[planet10]

We have used the W14. In a reflex enclosure it uses a very small box. To fit a woofT i'd have to see if Scott can do a suitable ML-TL. In a reflex they don't go all that low, but sound very good.

The SB Acoustics i would need to look at.

dave

 

[mudchute]

I'll discount the w14 then, not much point going to all this effort for little gain. Thanks for taking a look.

 

[chrisb]

isn't that a pair of W14s in the trapz MTMs? they certainly work quite well in the "ken" style vented enclosure - although those are modest enough size to not provide adequate height to act as a stand themselves, but something like the dual 830870s for FF85WK might work?


As pictured, approx 860mm for the woofT section, and with the upper enclosure inverted, the FF8WK was targeted to center at 1000mm

 

[planet10]

I'll discount the w14 then

Before you do that lets see what Scott can do. Vented not worthwhile for the application, but an ML-TL my turn out well.

dave

 

[planet10]

isn't that a pair of W14s in the trapz MTMs? they certainly work quite well in the "ken" style vented enclosure - although those are modest enough size to not provide adequate height to act as a stand

Yes, theMTM is W14 + FF85. 2 W14s fit (approx) into the same size 'Ken enclosure as the dMar-Ken so they indeed do not make a very good stand.

... dual 830870s for FF85WK might work?

4 might work, but it would shred the budget.

dave

 

[mudchute]

If they needed an enclosure similar in size to the mar-kens then I could extend the external dimensions and create a mass filled void under the W14 enclosure maybe?

This would allow the alpair to be placed at the correct height and give the whole thing some stabilty I guess.

 

[planet10]

If they needed an enclosure similar in size to the mar-kens then I could extend the external dimensions and create a mass filled void under the W14 enclosure maybe?

One could, but if the extra volume/height could be used for more extension i'd be happier.

dave

 

[chrisb]

After listening to the succession of dual and quad driver woofer arrays during the past year or so, I'd be very interested in a larger size push/push MLTL with the W14s - a helluva performer for the price.

 

[planet10]

Twin W14s fit nicely in an ML-TL woofT with internal height of 838mm. Tallish, you'll need to flip the dMar-Ken7.3 upside down.

dave

 

[mudchute]

That's great, thanks to you and your team!

I guess port size would need to be quite big, about 4"? And would the width/depth be the same as the kens, 239 x 227?

 

[planet10]

Vent is not all that big. A fullwidth slot on the back. Footprint is the same as your Mar-Kens.

I have only a few details to add and the basic drawing will be done.

dave

 

[chrisb]

Twin W14s fit nicely in an ML-TL woofT with internal height of 838mm. Tallish, you'll need to flip the dMar-Ken7.3 upside down.

dave

as with the walnut uwoofT/FF85WKs

it took almost as much time to align grain match/wrap the veneer on those 4 boxes as to build

almost,

 

[mudchute]

They looked superb. I am currently wondering how to get around that considering the kens and woofs will come from different sheets of wood...