MTM series wiring

[jonhexom]

Hello all, I really hope that this is not a stupid question. Is it practical to have a speaker system configured as a MTM and have the woofers wired in series? I do realize that 6dB of SPL will be lost in addition to any compensating circuits, and that the tweeter level would need to be reduced as well. The reason I ask is that I have 4 Peerless 830341 drivers (buyout) which are 4 ohms and if 2 are wired in parallel they would create a 2 ohm load. My affordable integrated amp just cannot take that kind of load, LOL. I just wondered if this was possible. Also, if anyone knows of any good designs using these woofers, I would really appreciate hearing about them. Thanks.

[hongrn]

http://i2.photobucket.com/albums/y48/hongrn/VeneeredCenter2.jpg


I used the 4-ohm Peerless 830344 buyouts and wired them in series for my center channel.

Hong

[biff]

> Hello all, I really hope that this is not a
> stupid question. Is it practical to have a
> speaker system configured as a MTM and have
> the woofers wired in series? I do realize
> that 6dB of SPL will be lost in addition to
> any compensating circuits, and that the
> tweeter level would need to be reduced as
> well. The reason I ask is that I have 4
> Peerless 830341 drivers (buyout) which are 4
> ohms and if 2 are wired in parallel they
> would create a 2 ohm load. My affordable
> integrated amp just cannot take that kind of
> load, LOL. I just wondered if this was
> possible. Also, if anyone knows of any good
> designs using these woofers, I would really
> appreciate hearing about them. Thanks.

You don't lose anything really. It's -3 for the impedance gain, but +3 due to two woofers, so no net loss, and you get the impedance amp friendly. I have some vifa pl 4 ohmers in series MTMs and they work fine - go for it!

[Dirk]

http://www.oceamedia.com/dirk/bravoxen.jpg


> You don't lose anything really. It's -3 for
> the impedance gain, but +3 due to two
> woofers, so no net loss, and you get the
> impedance amp friendly. I have some vifa pl
> 4 ohmers in series MTMs and they work fine -
> go for it!

Just don't forget to double the inductance if you do any modeling or are calculating a zobel. I'm running an MTM using the TM025F1 and two of the Bravox 5.25" buyouts from a couple years ago. 4ohm, series wired. Worked out pretty well, all in all.

[marks]

What sort of Veneer did you use on your speakers there Dirk? I remember a discussion a long time ago, but could you refresh my memory?

[Dirk]

> What sort of Veneer did you use on your
> speakers there Dirk? I remember a discussion
> a long time ago, but could you refresh my
> memory?

That is none other than PE's Maple veneer. The left hand image is the one that I gamma-corrected. Pending monitor brightness, that's the side that is closest to the "real color".

[marks]

Would you recommend the maple? Does it look nice in close up?

[Dirk]

> Would you recommend the maple? Does it look
> nice in close up?

I would definitely recommend it. It takes some close scrutiny to tell it's not real wood (inside an arms length). It looks good enough that, if you didn't know it was vinyl, you'd assume it was real veneer. Having used it and the cherry, I thought the maple looked very convincing where the cherry just did not. It's rich & warm, with just a tinge of red to it.

My one proviso is that NONE of the PE wood-grain vinyls hold up well for speakers that get moved around a lot, IMHO. The edges tend to catch on things and need to be smoothed back down.

Aside from that, I was able to cover 5 sides of a 3cu ft sub in under an hour. The one BIG upside as far as I'm concerned is that it's waterproof, so a sweaty glass does it no harm. :-)

[marks]

So you like the Maple better than cherry? Lots of people have said that the cherry looks better, but just from looking at pictures of the maple vinyl veneer, it looks better to me. Does it have any wood-grain texture to it or is it just smooth?
Thanks so much for your help!

> I would definitely recommend it. It takes
> some close scrutiny to tell it's not real
> wood (inside an arms length). It looks good
> enough that, if you didn't know it was
> vinyl, you'd assume it was real veneer.
> Having used it and the cherry, I thought the
> maple looked very convincing where the
> cherry just did not. It's rich & warm,
> with just a tinge of red to it.

> My one proviso is that NONE of the PE
> wood-grain vinyls hold up well for speakers
> that get moved around a lot, IMHO. The edges
> tend to catch on things and need to be
> smoothed back down.

> Aside from that, I was able to cover 5 sides
> of a 3cu ft sub in under an hour. The one
> BIG upside as far as I'm concerned is that
> it's waterproof, so a sweaty glass does it
> no harm. :-)

[Dirk]

> So you like the Maple better than cherry?
> Lots of people have said that the cherry
> looks better, but just from looking at
> pictures of the maple vinyl veneer, it looks
> better to me. Does it have any wood-grain
> texture to it or is it just smooth?
> Thanks so much for your help!

Kick me an email (just make sure read the reply from my spam filter). I've got some scrap of both the maple and cherry I can toss in an envelope.

[philip]

Provided Link: http://photobucket.com/albums/b105/phillyguy19020/NSBminiArray/?action=view&current=NSBminiArray02-2.jpg


Have never used the cherry but maple is great looking. Yes, maple has good grain, not really textured but it does have a wood checking similar to real wood. I like it.

Wood checking: term used for parallel cracking with the grain, in this situation sorta like a fine texture in one direction.

<A HREF="http://photobucket.com/albums/b105/phillyguy19020/NSBminiArray/?action=view&current=NSBminiArray02-2.jpg">http://photobucket.com/albums/b105/phillyguy19020/NSBminiArray/?action=view&current=NSBminiArray02-2.jpg</A>

> So you like the Maple better than cherry?
> Lots of people have said that the cherry
> looks better, but just from looking at
> pictures of the maple vinyl veneer, it looks
> better to me. Does it have any wood-grain
> texture to it or is it just smooth?
> Thanks so much for your help!

[jclin4]

I also found the wood grain on the red maple to be very convincing. I may be talking nonsense, but to me the grain appears to have "depth", meaning it somehow looks like the grains run deeper than just the surface.

Is there a terminology in woodworking to describe this sensation?

[biff]

[jonhexom]

Thanks for the info. Your center channel looks very nice.> I used the 4-ohm Peerless 830344 buyouts and
> wired them in series for my center channel.

> Hong

[jonhexom]

> You don't lose anything really. It's -3 for
> the impedance gain, but +3 due to two
> woofers, so no net loss, and you get the
> impedance amp friendly. I have some vifa pl
> 4 ohmers in series MTMs and they work fine -
> go for it!

Thanks. It's nice to know that can be done with my drivers.

[jonhexom]

> Just don't forget to double the inductance
> if you do any modeling or are calculating a
> zobel. I'm running an MTM using the TM025F1
> and two of the Bravox 5.25" buyouts
> from a couple years ago. 4ohm, series wired.
> Worked out pretty well, all in all. Thanks for the advice. Your speakers look great. I will definitely try the maple vinyl. I think I will go with an MTM then. I have the tweeters. Morel MDT 20s. Thanks again.

[robertcottiers]

> I used the 4-ohm Peerless 830344 buyouts and
> wired them in series for my center channel.

> Hong

Hong:You did a great job on your center channel speakers.A+ on workmanship!..Is the veneer from PE?

Regards Bob C.

[hongrn]

> Hong:You did a great job on your center
> channel speakers.A+ on workmanship!..Is the
> veneer from PE?

> Regards Bob C.

Thanks, Bob. I'm lucky enough to live close by 2 wood shops that specialize in paperbacked veneers. If only Dayton opened a branch in Southern California, my life would be complete...

Hong

[jclin4]

Interesting. A google search on the term Shetoyance reveals that it is used in the context of describing gemstones. It seems to mean the appearance of colored flames.

In veneer, perhaps it is the burls and knots that gives the illusion of 3 dimensions.