Dayton Aluminum MTM Kit

[davidzimmer]

I am very seriously concidering the Dayton Aluminum MTM Kit.

I'm convinced on the freq responce and spl. What I would like to know is. Has anyone heard these? I'm particulally interested in the imaging/staging.

I will drive these with a LM3886 gainclone which I am VERY satisfied with.

My music interest are Jazz (60's recordings), classic rock, and country.

I'm presently listening to a pair of Bose 201 Series II.

Any comemts from those who have heard the Dayton Aluminum MTM Kit will be appreciated.

Thanks,
David

[rudyjakubin]

> I am very seriously concidering the Dayton
> Aluminum MTM Kit.

> I'm convinced on the freq responce and spl.
> What I would like to know is. Has anyone
> heard these? I'm particulally interested in
> the imaging/staging.

> I will drive these with a LM3886 gainclone
> which I am VERY satisfied with.

> My music interest are Jazz (60's
> recordings), classic rock, and country.

> I'm presently listening to a pair of Bose
> 201 Series II.

> Any comemts from those who have heard the
> Dayton Aluminum MTM Kit will be appreciated.

Hi David,
First of all that tweeter would be suspect.
I'm guessing you want to know about the Dayton 7" Aluminum kit;
<A HREF="http://www.partsexpress.com/pe/showdetl.cfm?&DID=7&Partnumber=302-940">http://www.partsexpress.com/pe/showdetl.cfm?&DID=7&Partnumber=302-940</A>
If your any good with a router or have a friend who is than building your own kit would be the best way to go.
Pete Schumacher & I could set you with the finest tweeters in dome land and Pete's dynoMite crossovers and going TMM instead of MTM.
The box can be bought seperately;
<A HREF="http://www.partsexpress.com/pe/showdetl.cfm?&DID=7&Partnumber=302-750">http://www.partsexpress.com/pe/showdetl.cfm?&DID=7&Partnumber=302-750</A>
It's the same one in the kit...
If it's superb soundstage you want with accurate and deep bass this is the way to go.
There's the Seas 27TBFC, Vifa D26NC, North D25, Hi-Vi K1 tweeters with prices $29, $28, $18 & $9 each.
Rusty in TN just finished a pair using the Hi-Vi K1 tweeter;
<A HREF="http://www.pesupport.com/cgi-bin/config.pl?read=282317">http://www.pesupport.com/cgi-bin/config.pl?read=282317</A>

[davidzimmer]

My brother in law is going to build the boxes. 3/4 in. solid Cherry!!!

I plan on sticking to all demensions and using the same drivers and build the crossover on perfboard. If heard HORROR stories about noobs desighning their own speakers.

I AM open to suggestions and YES imaging is a high priority.

[rudyjakubin]

> My brother in law is going to build the
> boxes. 3/4 in. solid Cherry!!!

> I plan on sticking to all demensions and
> using the same drivers and build the
> crossover on perfboard. If heard HORROR
> stories about noobs desighning their own
> speakers.

> I AM open to suggestions and YES imaging is
> a high priority.

These two would be your best bet at imaging;
27TDFC (H1189) Textile dome;
<A HREF="http://www.madisound.com/cgi-bin/index.cgi?cart_id=1819731.27756&pid=1002">http://www.madisound.com/cgi-bin/index.cgi?cart_id=1819731.27756&pid=1002</A>
D26NC55 1” Textile dome tweeter;
<A HREF="http://www.madisound.com/cgi-bin/index.cgi?cart_id=2539961.741&pid=1325">http://www.madisound.com/cgi-bin/index.cgi?cart_id=2539961.741&pid=1325</A>
Although these two are real good also;
K1 Fabric Dome Tweeter;
<A HREF="http://www.madisound.com/cgi-bin/index.cgi?cart_id=2946519.734&pid=1824">http://www.madisound.com/cgi-bin/index.cgi?cart_id=2946519.734&pid=1824</A>
North Creek's D25's;
<A HREF="http://www.northcreekmusic.com/Drivers/Drivers.html">http://www.northcreekmusic.com/Drivers/Drivers.html</A>

You can't go wrong with any of them.
Besides these speakers will blow away what you've got right now. Excellent bass, clear mids and defined treble.
For Jazz and Country I really liked the North D25's, especially with female singers.
The Vifa was and all around winner in my book. It just played everything well.
The Seas 27TDFC has a rising frequency response in the top octave which makes brushed cymbals sound crystal clear. It might be too much for Rock though. The K1 is the winner here.
It would also be a good idea to line the inside walls with roofing felt and then cover the felt with open-celled foam. Brace it good because these 7" woofers can go deep and loud with a lot of punch.

[davidzimmer]

> These two would be your best bet at imaging;
> 27TDFC (H1189) Textile dome;

It will take me awhile to digest this. What makes you suspect of the original tweeter D25AG35?

If I were to go with the D26NC55, would it react properly with the same crossover?

Also the D25AG35 goes up to 35k. Can't find the freq responce of the D26NC55.

I'm sure anyway I go will sound great but, this will probably be the last speakers I ever own. I want to get the best imaging I can.

Thanks,
David

[kenc]

> It will take me awhile to digest this. What
> makes you suspect of the original tweeter
> D25AG35?

> If I were to go with the D26NC55, would it
> react properly with the same crossover?

> Also the D25AG35 goes up to 35k. Can't find
> the freq responce of the D26NC55.

> I'm sure anyway I go will sound great but,
> this will probably be the last speakers I
> ever own. I want to get the best imaging I
> can.

> Thanks,
> David

Nothing wrong with the D25, and the kit is designed for it and it alone, chances of a drop in replacement are anyone's guess. I think Rudy's just not a big fan of the D25. I think it's fair to say it's not the most popular tweeter these days, but I'm sure it works well in this kit.

Rudy's suggestions are good ones, if you aren't adverse to building your own speaker cabinets and assembling a crossover. The one difference might be in sensitivity....the MTM will have several dB's on the TMM's in Pete and Rudy's design. Still, power is cheap and the impedance is friendlier to amps and receivers.

You might try singling out John Stockman...If memory serves he's made the Aluminum kits and speaks very highly of them.

[Pete Schumacher ®]

> Nothing wrong with the D25, and the kit is
> designed for it and it alone, chances of a
> drop in replacement are anyone's guess. I
> think Rudy's just not a big fan of the D25.
> I think it's fair to say it's not the most
> popular tweeter these days, but I'm sure it
> works well in this kit.

> Rudy's suggestions are good ones, if you
> aren't adverse to building your own speaker
> cabinets and assembling a crossover. The one
> difference might be in sensitivity....the
> MTM will have several dB's on the TMM's in
> Pete and Rudy's design. Still, power is
> cheap and the impedance is friendlier to
> amps and receivers.

Actually, the TMM and MTM have identical sensitivity. They also present a similar impedance to the amp overall. The TMM 2.5-way does have a smoother power response and the improved vertical dispersion of a TM.

> You might try singling out John
> Stockman...If memory serves he's made the
> Aluminum kits and speaks very highly of
> them.

[rudyjakubin]

Well, there is better. 35khz???
Here you go;
<A HREF="http://www.madisound.com/cgi-bin/index.cgi?cart_id=8707041.28792&pid=1945">http://www.madisound.com/cgi-bin/index.cgi?cart_id=8707041.28792&pid=1945</A>
Scroll down 2/3 of the way and check this tweeter out;
<A HREF="http://www.zaphaudio.com/tweetermishmash/fr.html">http://www.zaphaudio.com/tweetermishmash/fr.html</A>

Also, Zaph and Mark's site is where we all here get our distortion data from. Also Jon Marsh has a few tweets he tested.
<A HREF="http://www.htguide.com/forum/forumdisplay.php4?f=6">http://www.htguide.com/forum/forumdisplay.php4?f=6</A>
<A HREF="http://206.13.113.199/ncdiyaudio/mark/Testing/testing.htm">http://206.13.113.199/ncdiyaudio/mark/Testing/testing.htm</A>
<A HREF="http://www.zaphaudio.com/">http://www.zaphaudio.com/</A>
To confuse things and muck it up a bit. There are ribbon tweets to consider.

Which brings me to an aside;
Pete?? What ribbon did you have in mind for the DA175's and RS52???

[Pete Schumacher ®]

Of all the planars Zaph tested, the BG Neo3PDR had the best numbers. But for a 4KHz XO, the Fountek looks like a winner, though a bit pricey at double the cost of the Neo3PDR.

> Well, there is better. 35khz???
> Here you go;
>
> <A HREF="http://www.madisound.com/cgi-bin/index.cgi?cart_id=8707041.28792&pid=1945">http://www.madisound.com/cgi-bin/index.cgi?cart_id=8707041.28792&pid=1945</A>
> Scroll down 2/3 of the way and check this
> tweeter out;
>
> <A HREF="http://www.zaphaudio.com/tweetermishmash/fr.html">http://www.zaphaudio.com/tweetermishmash/fr.html</A>
> Also, Zaph and Mark's site is where we all
> here get our distortion data from. Also Jon
> Marsh has a few tweets he tested.
>
> <A HREF="http://www.htguide.com/forum/forumdisplay.php4?f=6">http://www.htguide.com/forum/forumdisplay.php4?f=6</A>
>
> <A HREF="http://206.13.113.199/ncdiyaudio/mark/Testing/testing.htm">http://206.13.113.199/ncdiyaudio/mark/Testing/testing.htm</A>
> <A HREF="http://www.zaphaudio.com/">http://www.zaphaudio.com/</A> To confuse
> things and muck it up a bit. There are
> ribbon tweets to consider.

> Which brings me to an aside;
> Pete?? What ribbon did you have in mind for
> the DA175's and RS52???

[rudyjakubin]

> Of all the planars Zaph tested, the BG
> Neo3PDR had the best numbers. But for a 4KHz
> XO, the Fountek looks like a winner, though
> a bit pricey at double the cost of the
> Neo3PDR.

Is this it?
<A HREF="http://www.madisound.com/cgi-bin/index.cgi?cart_id=9493692.20580&pid=1888">http://www.madisound.com/cgi-bin/index.cgi?cart_id=9493692.20580&pid=1888</A>

I'm familiar with the B&G's. I got the Neo8PDR's.
Just itching to try a true ribbon.

I'm also going with removable baffles for that DA175 & RS52 box.
In case that Dayton 3/4" falls a tad/smidgen short.

[Pete Schumacher ®]

> Is this it?
>
> <A HREF="http://www.madisound.com/cgi-bin/index.cgi?cart_id=9493692.20580&pid=1888">http://www.madisound.com/cgi-bin/index.cgi?cart_id=9493692.20580&pid=1888</A>
> I'm familiar with the B&G's. I got the
> Neo8PDR's.
> Just itching to try a true ribbon.

Actually, Zaph tested the big brother.
<A HREF="http://www.madisound.com/cgi-bin/index.cgi?cart_id=9493692.20580&pid=1890">http://www.madisound.com/cgi-bin/index.cgi?cart_id=9493692.20580&pid=1890</A>

[johnastockman]

> Nothing wrong with the D25, and the kit is
> designed for it and it alone, chances of a
> drop in replacement are anyone's guess. I
> think Rudy's just not a big fan of the D25.
> I think it's fair to say it's not the most
> popular tweeter these days, but I'm sure it
> works well in this kit.

> Rudy's suggestions are good ones, if you
> aren't adverse to building your own speaker
> cabinets and assembling a crossover. The one
> difference might be in sensitivity....the
> MTM will have several dB's on the TMM's in
> Pete and Rudy's design. Still, power is
> cheap and the impedance is friendlier to
> amps and receivers.

> You might try singling out John
> Stockman...If memory serves he's made the
> Aluminum kits and speaks very highly of
> them.

Thanks, Ken...I've made both versions, the 5.25"/silkie and the 7"/Vifa. Not made for me, but for a few friends. If you're going to use the kit XO, stick with the original tweeter, as using another will require a new XO. Now I haven't heard the version that Rudy and Pete are talking about, but with their skills, I'd give the nod for imaging and accuracy to the one Rudy is referring to. I had the 7"/Vifa version at my place for about a week, and for the price, they are an excellent value. You'd have to spend much more in the retail market to get something even close, and the quality of the PE cabinet is certainly better than more expensive name brands. And this from someone who worked at an audio emporium for many years here in the Seattle area. I couldn't find anything wrong with the two pairs I made for friends...imaging was great, highs had detail w/o harshness, mids were very well balanced and the bass was impressive for two 7" woofers. The folks who got them are extremely happy, but are not critical listeners or "audiophiles". Just lovers of good music. That said, I'd still go with what Rudy and Pete have done. I wish that design was around when I put those kits together. Good luck!

John A.

[kenc]

> Actually, the TMM and MTM have identical
> sensitivity. They also present a similar
> impedance to the amp overall. The TMM
> 2.5-way does have a smoother power response
> and the improved vertical dispersion of a
> TM.

Hi Pete,
I think I'm missing something here, the vertical dispersion/power response stuff I understand, but I thought the TMM had a sensitivity of about 83 vs 86.5 for the MTM? Am I wrong? The MTM gets the +6 dB increase, doesn't the TMM just benefit from not losing the sensitivity from baffle step compensation?

Thanks Pete

[Pete Schumacher ®]

> Hi Pete,
> I think I'm missing something here, the
> vertical dispersion/power response stuff I
> understand, but I thought the TMM had a
> sensitivity of about 83 vs 86.5 for the MTM?
> Am I wrong? The MTM gets the +6 dB increase,
> doesn't the TMM just benefit from not losing
> the sensitivity from baffle step
> compensation?

> Thanks Pete

Both the MTM and TMM are attempting to compensate for BSC. If both designs accomodate the same BSC (4dB for example), their responses will both show the same sensitivity.

The difference is that near the XO point, the .5 woofer is producing only a fraction of the total leaving the single woofer to produce the rest. In MTM 2-way, the total SPL is the same, but both woofers are only doing half duty instead of one doing closer to full duty.

Midrange distortion may be a bit lower in the MTM at the expense of off-axis and power response performance when compared to the TMM 2.5-way.

[davidzimmer]

> Thanks, Ken...I've made both versions, the
> 5.25"/silkie and the 7"/Vifa. Not
> made for me, but for a few friends. If
> you're going to use the kit XO, stick with
> the original tweeter, as using another will
> require a new XO. Now I haven't heard the
> version that Rudy and Pete are talking
> about, but with their skills, I'd give the
> nod for imaging and accuracy to the one Rudy
> is referring to. I had the 7"/Vifa
> version at my place for about a week, and
> for the price, they are an excellent value.
> You'd have to spend much more in the retail
> market to get something even close, and the
> quality of the PE cabinet is certainly
> better than more expensive name brands. And
> this from someone who worked at an audio
> emporium for many years here in the Seattle
> area. I couldn't find anything wrong with
> the two pairs I made for friends...imaging
> was great, highs had detail w/o harshness,
> mids were very well balanced and the bass
> was impressive for two 7" woofers. The
> folks who got them are extremely happy, but
> are not critical listeners or
> "audiophiles". Just lovers of good
> music. That said, I'd still go with what
> Rudy and Pete have done. I wish that design
> was around when I put those kits together.
> Good luck!

> John A.

John,

Thanks for posting! I went to your site and was impressed! I couldn't quite figure out how to ask you what I needed, but you already knew. Thanks.

So if I stick to the original (7" / vifa), I'll be very happy. But I'd be happier with Rudy's plan?

Ok Rudy. In your plan, do I change tweeters and x-over? Could you spell it all out for me? I am totally in the dark but smart enough to realize it. :-)

Thanks,
David

[rudyjakubin]

http://img.photobucket.com/albums/v641/rjakubin/TMM_DA175_NC-D25_2.gif


> Ok Rudy. In your plan, do I change tweeters
> and x-over? Could you spell it all out for
> me? I am totally in the dark but smart
> enough to realize it. :-)

Since you are building your own boxes it makes sense.
Have you decided to go TMM or MTM and which tweeter?
Depending what tweeter and configuration you choose the crossover will look like this;

[davidzimmer]

> Since you are building your own boxes it
> makes sense.
> Have you decided to go TMM or MTM and which
> tweeter?
> Depending what tweeter and configuration you
> choose the crossover will look like this;

I'm set on the MTM configuration. I get the sense that everyone leans towrd the D26NC55 for imaging. So the two Dayton 7" woofers, the D26NC55, and the above crossover is what you are suggesting will be an improvement?

[kepler]

> Actually, the TMM and MTM have identical
> sensitivity. They also present a similar
> impedance to the amp overall. The TMM
> 2.5-way does have a smoother power response
> and the improved vertical dispersion of a
> TM.

How does the horizontal dispersion compare between the TMM and the MTM? Can you generalize or do you need to look at an individual case?

thanks

[Pete Schumacher ®]

> How does the horizontal dispersion compare
> between the TMM and the MTM? Can you
> generalize or do you need to look at an
> individual case?

> thanks

Horizontal dispersion at the tweeter level should be very similar. However, as you move above and below that axis, there will be large differences due to the woofers causing large nulls in each other's outputs.

There will be differences from system to system depending on the type of XO, even or odd, but in general, the description above holds I believe.

[Pete Schumacher ®]

http://i12.photobucket.com/albums/a203/pete_schumacher/TMM_DA175_HiVI-K1_project.gif


> I'm set on the MTM configuration. I get the
> sense that everyone leans towrd the D26NC55
> for imaging. So the two Dayton 7"
> woofers, the D26NC55, and the above
> crossover is what you are suggesting will be
> an improvement?

Use this schematic but change a couple of values on the tweeter circuit.

Change the 7Ω to 6Ω and the 8Ω to 10Ω

Do that, and the response curve will be nearly a clone of what you see displayed for the K1.

[Pete Schumacher ®]

One more point.

The polar response of the system will change depending on where the .5 woofer is. For the "normal" polar response of a TM, put the .5 woofer on top. This way, the response as you move above the tweeter axis remains flat to higher angles. Otherwise, you'll reverse that pattern and have more uniform response below the tweeter axis, probably not a desireable feature in most cases.

[davidzimmer]

> Use this schematic but change a couple of
> values on the tweeter circuit.

> Change the 7Ω to 6Ω and the
> 8Ω to 10Ω

> Do that, and the response curve will be
> nearly a clone of what you see displayed for
> the K1.

Ok. I'm with ya. Educate me on the woofer hook up. Why a difference between upper and lower.

Thanks

[rudyjakubin]

> One more point.

> The polar response of the system will change
> depending on where the .5 woofer is. For the
> "normal" polar response of a TM,
> put the .5 woofer on top. This way, the
> response as you move above the tweeter axis
> remains flat to higher angles. Otherwise,
> you'll reverse that pattern and have more
> uniform response below the tweeter axis,
> probably not a desireable feature in most
> cases.

Maybe tomorrow my crossover parts will be here so I can try out Roman's 2.5 on the DR. K's MTM. I was just going to do that. Put the .5 on top. It kind of makes sense, since the .5 is taken out of the frequency response where lobing becomes an issue as with regular MTM's.

Roman's site;
<A HREF="http://www.rjbaudio.com/RS180MTM/rs180-rs28-mtm.html">http://www.rjbaudio.com/RS180MTM/rs180-rs28-mtm.html</A>

[Pete Schumacher ®]

> Ok. I'm with ya. Educate me on the woofer
> hook up. Why a difference between upper and
> lower.

> Thanks

Check out Rudy's post:
<A HREF="http://www.pesupport.com/cgi-bin/config.pl?read=282616">http://www.pesupport.com/cgi-bin/config.pl?read=282616</A>

He sums it up. By putting the "full range" woofer on the bottom, you get the polar response of a normal TM. Otherwise, it would be like taking a regular TM with a 4th order XO and standing it on it's head. On axis, no difference but big difference depending on which direction you move up or down. A regular TM 4th order XO has a response null below the tweeter axis. It's much more uniform above the tweeter axis.

[Pete Schumacher ®]

> Ok. I'm with ya. Educate me on the woofer
> hook up. Why a difference between upper and
> lower.

> Thanks

Just in case I misunderstood . . . The "lower" woofer in the schematic is the .5 woofer. The "upper" woofer is the one running to the 2KHz XO point. This is called a cascaded 2.5-way where both woofers are sharing the same upper crossover circuit to acheive a better phase alignment between the two woofers through the XO region and aiding in attenuation of the .5 woofer which is only a 1st order XO.

[johnastockman]

Provided Link: My humble host site (http://custom.smugmug.com/gallery/115064/1)


> Ok. I'm with ya. Educate me on the woofer
> hook up. Why a difference between upper and
> lower.

> Thanks

David, thanks for the kind words above! I still have a ways to go when it comes to XO design, but I've built many of the "Other Person's Designs" and haven't been disappointed yet. You said also that you wanted these speakers to be something you could have for a long time, but beware that this is a highly addictive hobby! But if you just want to build one pair of really kick-a** speakers, I believe the 2.5 design is the way to go. Roman and the others have done some very nice stuff, and I have learned a wealth of knowledge from going to their sites and reading their posts. Let us know how you're doing and if you have any more ?'s...and don't feel like any question is too simple or "dumb". We love to see pics, also! If you want, you could send them to me, I'll put them up at my site and post them here for you...that is if you don't have a place to host your photos.

John A.