How does this MTM design look?

[DaveFred]

I am looking to build a MTM design using the following,


Two Dayton Audio DA175-8 7" Aluminum Cone Woofers, one Dayton Audio DC28F-8 1-1/8" Silk Dome Tweeter and this 2K crossover in a 1 cubic foot sealed box.

I have tried to find threads on the DA175-8, but not much has been written about them.

Your thoughts on this design?

Thank you,

David, London, Canada.

 

[planet10]

Dave,

The generic XO is not likely to be very good, one needs to do the XO for the particular drivers.

And do keep in mind in an ideal world, midbass centre-to-centre will be less than a quarter wavelength at the XO frequency.

dave

 

[Lojzek]

I am looking to build a MTM design using the following...

Your thoughts on this design?
Thank you,
David, London, Canada.

Hi David, my thoughts, it's doable but one would first need to simulate to arrive at a decent enough of a filter solution which would be better than any off the shelf crossover. If I may suggest bringing your attention to this very fine piece of technology as an alternate solution. US$ 29/piece is probably as good of an offer as practically possible.


Peerless PPB 830874 - 6.5" Poly Cone Woofer

 

[planet10]

Woe, those are on sale cheap. We have been very happy with the 4” variant as a helper woofer in one of our WAWs.

dave

 

[Mario Pankov]

Yes, they`ve been on sale for quite some time. If he already bought the Dayton woofers and wants it to be an MTM, I think a small fullranger would do better instead of a tweeter.

 

[Lojzek]

MTM - truncated frames drivers

One of the many combinations.

 

[Mrcloc]

I recently used two 6.5" mid-basses crossed at 2.3kHz and the result is fantastic. The drivers have actually got a larger overall chassis diameter than those DA 7" ones you linked. The key to breaking the rules with MTM is to design steep crossovers. As has been said, the crossover you linked won't cut it.

The 7" drivers will provide a lot more sub-bass than the Peerless linked, but I'm not saying it's better. I wouldn't know.

I'll follow this.

 

[Dissi]

Zaph has designed an MTM with those Dayton aluminum cone woofers and various cabinet options: Bargain Aluminum MTM

 

[planet10]

... I think a small fullranger would do better instead of a tweeter.

I can’t disagree with that…it removes so much of what is “evil” about crossovers.

dave

 

[chrisb]

Well, more like relocating it to a point much lower than our hearing's most sensitive region. - i.e. between 200 -300Hz rather than the anywhere from 1-3kHz often seen in 2 ways. If you can afford the expense of additional amps - how many of us don't have one or two of those kicking around? - going active with something as simple as PLLXO can eliminate passive high level components altogether.

 

[jcandy]

Zaph has designed an MTM with those Dayton aluminum cone woofers and various cabinet options: Bargain Aluminum MTM

Right. The BAMTM is also a 1 cu-ft sealed design, so unless the TS is willing to do a proper design from scratch I would suggest building the BAMTM.

 

[DaveFred]

Right. The BAMTM is also a 1 cu-ft sealed design, so unless the TS is willing to do a proper design from scratch I would suggest building the BAMTM.

I looked up the BAMTM, and that looks like exactly what I want to build. The only problem is finding the SEAS 27TBFC/G tweeter. It has been discontinued. Anything I find about this design and build is 10 years old. Anyone build this speaker recently?

What would a good replacement be for the SEAS 27TBFC/G tweeter?

Thank you,

David.

 

[Frabor]

The tweeter is available

I want to build the bamtm with active xover (mini DSP). just checked on the madisound web site and it seems that the tweeter is available. My intention is to modify the length of the enclosure to use 1' x 4' 3/4 MDF shelving. Planning to use a minidsp per channel as I want to add subs in the future.