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**chrisn** · 01-06-2021, 11:11 PM

I'd choose the tweeter you have over just one of the 15w mids in a WMTW format, even though it would bug me to have an extra driver. Of course you could use both 15w's as woofers flanking a 12mu as a mid.

**Justtheone** · 01-07-2021, 12:14 AM

You see my small dilemma
Yes it is bugging me thinking about the extra driver, hence why I'm looking at the 18w 8545/01 and the 12 mu so I can use both 15w drivers,so you think wmtw etheir way ?
cheers

**tvrgeek** · 01-07-2021, 10:03 AM

You have made no comments on your crossover point to your sub. Why a 10 inch woofer for your center? A pair of those 7's with offset tweeter would seem appropriate. Offset as to not cause too much horizontal beaming. Go crazy with 4 of the 7's for even lower distortion, though 2 should be able to remain under 1% up to the threshold of pain. Do the model and see if they can remain at less than half X-max to 110 dB to the crossover point. If you have the space for a 10 inch driver, you have the space to cram the 7's close with the tweeter just above. Superior to the MTM horizontal of most systems.

**Justtheone** · 01-07-2021, 12:58 PM

I will cross over at 80 hz, the mains will be for music as well,I'd say 50 % ht 50 % music, the mains are going to have the 10 inch woofers,which are being designed. The mains are a ported,around 80L for the woofer and mid and tweeter in there own compartments.
I'm still reading and trying to absorb all the complicated mathematics behind this art, crossovers are way above my head but I realized 3 months ago,i still have to read up and try,for my first and last build I decided to get the xo built for me by an expert with vast experience.
My main focus is the centre speaker,I may be getting ahead of myself but wanted to finalize purchasing the last few drivers.
The centre will be a three way,etheir wmtw or wmtwm horizontal centre, I prefer the idea of the 2 x 7inch woofers placed at the ends with the tweeter and 2 x 5 inch in the pyramid formation so I can get the mids close as I can.
The 2 x 18w 8545/01 can have there own ported 20 odd L section at the ends then position the 2 x 15w 4531/G00 with the tweeter nestled snugly above and center.
The mains will have 2 denon poa T10 and the centre will be run by a poa T3.
so no 10 inch in the centre, that wood be huge.
cheers

**chrisn** · 01-07-2021, 08:37 PM

18w's flanking a 12mu would be pretty nice. Is that tweeter a small flange or large?

**tvrgeek** · 01-07-2021, 09:40 PM

You need to keep reading. Your money of course.

**Justtheone** · 01-08-2021, 09:13 AM

18w's flanking a 12mu would be pretty nice. Is that tweeter a small flange or large?

Thank you for the input chrisn
It's a large 10 cm flange on the tweeter,
Why I was going in the direction of wmtmw is because the spacing of drivers, measuring for wavelength ,I'm not cutting the tweeter or slicing a notch in it.The pyramid position like the khanspire centre seems the way forward with the 18w etheir side, that way I can use both 15w and only have to buy 2 more drivers.

tvrgeek

You need to keep reading. Your money of course.

pot, kettle black springs to mind.
yes I need to read more obviously.
you need to reread my original post again, if you want to of course.
My bad if you think your last statement was helpful.
Again I'm still studying, I'm not trying to be an expert, I need a little constructive help that's all.
So you suggest the 2 7's flanking the pyramid of the 2 5's and 4 inch tweeter?

I don't have any speaker programs to do a simulation of the drivers,I dont even have a program for my design.
I just like to enjoy my projects and draw,design by hand and eye. The internet is my resource, you just have to sort out the the facts from the fiction, so many good engineers stroke designers out there sharing there knowledge.
I may even treat you to some photos of my build when I start it.

.

Cheers

**chrisn** · 01-08-2021, 06:11 PM

How big are you planning to make the cabinet?

Suggestions for the mid:

https://www.parts-express.com/scan-s...BoCO0MQAvD_BwE

Scanspeak Discovery 10F/4424G smaller diameter would allow closer CTC with the tweeter

https://www.parts-express.com/dayton...4-ohm--295-378

I've yet to see anyone do this, but I've simulated a horizontal MTM with a 2.5 crossover. Off axis wasn't symmetrical but was better than 2 way horizontal mids, and you wouldn't have to buy any drivers.

**Justtheone** · 01-09-2021, 03:50 PM

I was advised from the start to build 3 cabinets the same LCR, my OCD kicked in and I also have a unit holding my equipment which is directly under my TV and well a horizontal cc was me being a symmetry slave.

The centre speaker in the wmtmw configuration will be.
84cm 34 inches L
36cm 14 inches W
26cm 10 inches H
Distance between tweeter and mid is,or can be around 14-15cm which is 5.7-6.5 inches.
distance between mids is around 18cm, which is 7 inches.
distance between woofers is around 58cm which is 23 inches.

I need to read up on the 10f dome but think it would be inferior to the 12mu on initial investigations, thanks for the suggestion.
I have not designed the cabinet for the wmtw but think its all the same apart from length. It's also full range which I've read if I put a mid range or full range driver in the centre it's an instant miss match to my mains ?more reading needed the maddening thing is most threads go off on a tangent or just end with no definitive answers,its such a diversified subject but in the end its about what you sacrifice in order to make something better. Compromises.

This is only on paper, it's about 50 L without any displacement of bracing or drivers,2.2 cm MDF.
It will sit on the centre hifi unit and sit slightly lower than the mains.
Cheers

A correction
The mids I have are 15w 4531/k00 not G00

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