Morel WMTMW advice

[gronker]

Hi

I am considering building a pair of WMTMW using the following Morel drivers: DMS37, MDM55, MW267

I've done a few small projects before but nothing of this size and cost and am after advice on whether it's a good idea? Does anyone have experience or knowledge of these drivers and whether they would be good in this configuration.

I'm going with Morel as the person who is selling them to me has a lot of experience with speaker design and has kindly offered to help me with the design - if I buy Morel drivers from him.

For the price, particularly for the Neolin MW267, I could get some Seas Excel drivers which seem a lot more popular in diy land.

I would welcome any opinions people had as to whether it is a good idea to stick a whole pile of Morel drivers in a big box or not.

Thanks

[Ricky]

Hi.

I have a lot of experience with Morel Drivers. Ask, and I will tell you.

Good choice of units. Better than SEAS, Scanspeak etc, except Scanspeak tweeters tho.


Ricky

[gronker]

Hi Ricky

As this would be a very advanced project for my level of experience I was hoping to use these forums as a check against the design of the speakers.

At this stage I'm no further than the concept of these drivers in a tall, thin box either rectangular or with angled sides in a WMTMW configuration.

I calculated a box volume of 63L for 2 of the MW265s per box and was intending to mount them vertically as close together as feasible.

The box will be plywood or 25mm MDF, very strongly braced and with a full height grill cloth cover, a large base and possibly some sand in a chamber at the bottom to lower the centre of gravity and I believe deaden the box response. I have young kids so want them to stay upright and not have interesting things to poke. The box will be quite tall and narrow at the front with either a rectangular cross section or sides angling in to the rear.

If I rebate in the tweeter and surface mount the mid and woofers then apparantly they will be time aligned to 0.5mm.

The vendor is going to provide cross over schematics, I believe they will be first order but not sure of the frequencies yet.

I want to keep the overall design as simple as possible while still trying to cover the important design considerations.

How is this sounding so far? Am I on the right track or do I have my head in the clouds?

Thanks

[Ricky]

Hi.

I've been using Morel Drivers for nearly 10 years now. To give you a bit of history, the guy who formed Morel and the guy who formed Dynaudio were, in fact, together at some point. They parted company but share the 3" voice coil technology.

Morel units are damned expensive but, in my experience, produce really solid bottom end in smaller cabinets. Morel actually recommend using the MW265/266 in a sealed enclosure. I tried this and the results were naff. My favourite is the MW168. A good sturdy driver, low Vas and a res of 44.00Hz. I actually use two of these in parallel but one of them has a 4.7mH choke in series.This is then wired in parallel with the other. Both drivers come up from resonance but the one with the choke on it rolls off at about 500Hz whilst the 2nd one goes up to crossover frequency. AR used this principle many years ago.

If it were me, I'd bin the MDM55 and go for a good quality tweeter. Either a Scanspeak or Morel's own MDT range. Unless you spend ages *******' it, 3 way designs are notoriously difficult to get right unless you go active. Very few commercial makers do 3 way designs now. Other people on this forum will disagree but there must be a reason why there aren't more 3 way designs out there. 21/2 way is the easiest route at this point, especially if you have limited experience.

Ricky

[gronker]

Thanks for the advice Ricky, that sounds a bit more sensible. I was also recommended the MW168 but was worried it wouldn't give me enough bass. 2 1/2 way is probably the one to go for. Which of the MDT range would you think best suits it?

Keeping the cost down also leaves my options open to build a full 5.1 system with these as the mains.

[gronker]

Sorry for the delays in my responses - I'm new & still under moderation. Would the MDT33 match well with a couple of the MW168s?

[Ricky]

MDT 33 is an excellent choice. Crossover needs to be around 2500 - 300Hz. Don't cross at 3500Hz. The ear is particularly sensitive to any phase shift at that point. Don't ask me why coz I don't know. A 12dB crossover will suffice for the bass but if you decide to cross at 2500, you will need a steeper skirt on the filter. 18dB Butterworth is my preferred slope.

Ricky

[gronker]

Thanks for your help - I'll check with my Morel man over here and see if he has those tweeters. I'll get back on and post when I have a bit more of a detail design happening. Your assistance is much appreciated.

[Ricky]

The MW168's need a cabinet of about 45 litres, a minimum port internal diameter of 7 cms with a length of 11 cms. If you arrange the woofers in a D'Appolitto array, make the top one go to crossover. Position the port slap bang behind the tweeter. If you're making the cabinet out of 25mm material, no need for ballast. Make a bottom plinth out of 25mm material that is 25-40mm wider all the way round than the footprint of the cabinet.

I've got a crossover design for the 168's at the factory. E mail me at techsupport@arcaydis.com and I'll sort it out for you.

Ricky.

[richard_majer]

Wasn't your former idea to have WMTMW? With 2 1/2 you will still keep your target? I'm not sure you are going right direction... You can have them small speaker which will work pretty the same. I feel you will not have what you have described on your first post. Keep your 3way idea. I don't say 8" is not good... I have simmilar plan as you have had. WMTMW. I'm just playming with idea 2x10" or WWMTMWW with 4x8".
Defitelly I will make cross around 250-500Hz