"Moser" plans?

[brianp]

Hi Pete S. and NepaEric. Sounds like these are some fine little budget speakers. I know a couple of people looking for something "small, cheap, and good." Do you have the box and xo plans posted somewhere?

[Pete Schumacher ®]

> Hi Pete S. and NepaEric. Sounds like these
> are some fine little budget speakers. I know
> a couple of people looking for something
> "small, cheap, and good." Do you
> have the box and xo plans posted somewhere?

<A HREF="http://www.pesupport.com/cgi-bin/config.pl?read=391821">http://www.pesupport.com/cgi-bin/config.pl?read=391821</A>

I think this is the XO used by Eric, but there may be another that I sent him.

I'll let him confirm.

[Pete Schumacher ®]

> Hi Pete S. and NepaEric. Sounds like these
> are some fine little budget speakers. I know
> a couple of people looking for something
> "small, cheap, and good." Do you
> have the box and xo plans posted somewhere?

I had two versions. This is the super budget version that Eric built I do believe.

The XO posted in an earlier thread is the more expensive (and no more effective) version. If you use NPE caps, this XO is dirt cheap.

[nepaeric]

Merry Christmas!

Yes, Pete. This is the crossover I built for Jim's speakers he found in the garbage. It's very simple to duplicate, and I built Jim's pair of xover networks on a piece of 1/4" luan plywood, soldered in with spade connectors, and glued in with clear silicone. We built them based on the "Moser" design with a DA-175 aluminum cone woofer and a HiVi Research K-1 tweeter. I'd imagine an X-1 would yield the same or similiar result.

I don't know that we are using an optimum box, at .65 cubic ft, as these were found, not built for this specific woofer. We stuffed the heck out of them with ordinary Polyester Fiberfil. I would have prefered Acoustastuf, but Jim is budgeted, so we let price be out guide, and headed to WalMart for a 20 ounce bag. I have reason to believe, though, that they are close, but a little bit on the small side, at .65 cu ft, but it really doesn't seem to affect thier performance, as these are excellent! As a point of reference, (but do not trust it as absolute accuracy, as they have been way off IME, IMHO), PE's chart suggests a .4 cu ft enclosure as optimum. I think if I were to build a box, as apposed to salvaging a nice one from the trash, I would have built it approximately 0.8 cubic ft, and used a 1" diameter, 2"L vent tube. But then, maybe I might have to have Pete whip up another, different crossover.- ????

They are not efficient speakers, but the sound quality is exceptional. They won't shake your house, but they will fill a room with accurate tight bass and smooth upper and middle frequencies.

These are truly an economical, budget audiophile marvel and wonder. Build them. You won't be sorry you did. Jim is showing everyone in town and telling everyone around here how these will kick Polk or Boston Acoustic's butts, and wipe the floor with Bose. (Well, that wouldn't take much, anyway....)

He even made it a point to tell the guy at Best Buy or Circuit City (not sure which) while attempting to sell a guy a pair of speakers. According to Shelly, (Jim's wife) he got the salesman so mad he almost got kicked out with his family! If you build these, don't do what Jim did. Just sit back, enjoy your speakers and grin smugly the next time you see a "victim" buying a pair of Klipsch bookshelves and be thankful you came here, instead.

Good Luck in your venture, and DIY speaker building endeavor, whatever you decide to build.

Best Holiday Wishes
and Warm Regards,
Eric

[nepaeric]

Also, just wanted to point out to you, in case you are having doubts: The reason I say to you these are not efficient is due to low driver sensitivity, and addition BSC in the crossover. If you have plenty of amplifier power, do not worry about this.

Also, my reasons for suggesting the vented, larger enclosure was to achieve an even greater bass range and help compensate for the low efficiency by implementing a more efficient cabinet design. It's just an opinion, and I could be wrong. If you build it either way, it will likely be excellent.

I am building a mass-loaded transmission line tower speaker pair, modeled by Paul K, and crossover designed by Pete, around this same 7" Dayton driver and anticipate outstanding results.

Happy Holidays!
Eric

> Merry Christmas!

> Yes, Pete. This is the crossover I built for
> Jim's speakers he found in the garbage. It's
> very simple to duplicate, and I built Jim's
> pair of xover networks on a piece of
> 1/4" luan plywood, soldered in with
> spade connectors, and glued in with clear
> silicone. We built them based on the
> "Moser" design with a DA-175
> aluminum cone woofer and a HiVi Research K-1
> tweeter. I'd imagine an X-1 would yield the
> same or similiar result.

> I don't know that we are using an optimum
> box, at .65 cubic ft, as these were found,
> not built for this specific woofer. We
> stuffed the heck out of them with ordinary
> Polyester Fiberfil. I would have prefered
> Acoustastuf, but Jim is budgeted, so we let
> price be out guide, and headed to WalMart
> for a 20 ounce bag. I have reason to
> believe, though, that they are close, but a
> little bit on the small side, at .65 cu ft,
> but it really doesn't seem to affect thier
> performance, as these are excellent! As a
> point of reference, (but do not trust it as
> absolute accuracy, as they have been way off
> IME, IMHO), PE's chart suggests a .4 cu ft
> enclosure as optimum. I think if I were to
> build a box, as apposed to salvaging a nice
> one from the trash, I would have built it
> approximately 0.8 cubic ft, and used a
> 1" diameter, 2"L vent tube. But
> then, maybe I might have to have Pete whip
> up another, different crossover.- ????

> They are not efficient speakers, but the
> sound quality is exceptional. They won't
> shake your house, but they will fill a room
> with accurate tight bass and smooth upper
> and middle frequencies.

> These are truly an economical, budget
> audiophile marvel and wonder. Build them.
> You won't be sorry you did. Jim is showing
> everyone in town and telling everyone around
> here how these will kick Polk or Boston
> Acoustic's butts, and wipe the floor with
> Bose. (Well, that wouldn't take much,
> anyway....)

> He even made it a point to tell the guy at
> Best Buy or Circuit City (not sure which)
> while attempting to sell a guy a pair of
> speakers. According to Shelly, (Jim's wife)
> he got the salesman so mad he almost got
> kicked out with his family! If you build
> these, don't do what Jim did. Just sit back,
> enjoy your speakers and grin smugly the next
> time you see a "victim" buying a
> pair of Klipsch bookshelves and be thankful
> you came here, instead.

> Good Luck in your venture, and DIY speaker
> building endeavor, whatever you decide to
> build.

> Best Holiday Wishes
> and Warm Regards,
> Eric

[brianp]

Looks pretty straightforward, and I have most of the parts except the big coils. I'd probably use at least cheap mylars in the highpass. What is the ultimate acoustic slope these achieve--LR4? Also, what do you think is the optimal box volume and vent dimensions for these?

> I had two versions. This is the super budget
> version that Eric built I do believe.

> The XO posted in an earlier thread is the
> more expensive (and no more effective)
> version. If you use NPE caps, this XO is
> dirt cheap.

[nepaeric]

We used ordinary NP electrolytics in our "Mosers," which is what I chose for my TL, as well. If you are on a budget, I doubt you'd notice a difference with the mylars, and would save a signifigant amount on the xover buying bennics or cheapos, where possible.

I'm interesting in hearing your results.

Regards,
Eric

> Looks pretty straightforward, and I have
> most of the parts except the big coils. I'd
> probably use at least cheap mylars in the
> highpass. What is the ultimate acoustic
> slope these achieve--LR4? Also, what do you
> think is the optimal box volume and vent
> dimensions for these?

[Pete Schumacher ®]

> Looks pretty straightforward, and I have
> most of the parts except the big coils. I'd
> probably use at least cheap mylars in the
> highpass. What is the ultimate acoustic
> slope these achieve--LR4? Also, what do you
> think is the optimal box volume and vent
> dimensions for these?

There's no "optimum" box size for the DA175 in a vented alignment. The Qts is a bit on the high side, making them a better fit for a sealed box.

But if you're going to vent them, get at least .75 cubic feet behind them. And you'd want to tune them very low in order to keep the peaking around 80Hz under 1dB. Even a 2" diameter vent would be around 16" long. Going with a 1.5" diameter vent would probably be OK, but even it would have to be about 8" long. It may seem odd, but a passive radiator would be perfect in this situation, and the Dayton SD215-PR would be a perfect fit for any box volume between .75 and 1.5 cubic feet, without adding any mass to it.

But to keep these really budget, I'd go with the 8" long, 1.5" diameter vent and .75 cubic feet.

[Pete Schumacher ®]

> There's no "optimum" box size for
> the DA175 in a vented alignment. The Qts is
> a bit on the high side, making them a better
> fit for a sealed box.

> But if you're going to vent them, get at
> least .75 cubic feet behind them. And you'd
> want to tune them very low in order to keep
> the peaking around 80Hz under 1dB. Even a
> 2" diameter vent would be around
> 16" long. Going with a 1.5"
> diameter vent would probably be OK, but even
> it would have to be about 8" long. It
> may seem odd, but a passive radiator would
> be perfect in this situation, and the Dayton
> SD215-PR would be a perfect fit for any box
> volume between .75 and 1.5 cubic feet,
> without adding any mass to it.

> But to keep these really budget, I'd go with
> the 8" long, 1.5" diameter vent
> and .75 cubic feet.

The acoustic alignment of the XO is LR4 at 2200Hz. Cap choice is totally up to you. Mylars will be just fine.

[Wolf]

> There's no "optimum" box size for
> the DA175 in a vented alignment. The Qts is
> a bit on the high side, making them a better
> fit for a sealed box.

> But if you're going to vent them, get at
> least .75 cubic feet behind them.

Shawn used them in the BR1 cabs, which is .6ft^3 tuned to 55 Hz, and they thrive in there! I see no reason to go larger with the DA175, IMO/IME.
Later,
Wolf

[Pete Schumacher ®]

> Shawn used them in the BR1 cabs, which is
> .6ft^3 tuned to 55 Hz, and they thrive in
> there! I see no reason to go larger with the
> DA175, IMO/IME.
> Later,
> Wolf

The alignment above will produce a HUGE bump in the response centered at 66Hz, and by huge I mean at least 4dB, but closer to 7dB.

35Hz would be much better, producing a peak of only 2dB. That's based on measured TS parameters of course, not published specs. But even the published specs show a peak of just over 5dB at 66Hz. Just a little too boomy for my taste, but everyone has their own favorite flavor.

[brianp]

I need to copy the published specs into a box calculator and model this. Pressed for time right now, though, so just asking for a ballpark idea on box volume and expected f3. Probably looking at a lower Q alignment (around 0.5?), to reduce LF boom.

> There's no "optimum" box size for
> the DA175 in a vented alignment. The Qts is
> a bit on the high side, making them a better
> fit for a sealed box.

> But if you're going to vent them, get at
> least .75 cubic feet behind them. And you'd
> want to tune them very low in order to keep
> the peaking around 80Hz under 1dB. Even a
> 2" diameter vent would be around
> 16" long. Going with a 1.5"
> diameter vent would probably be OK, but even
> it would have to be about 8" long. It
> may seem odd, but a passive radiator would
> be perfect in this situation, and the Dayton
> SD215-PR would be a perfect fit for any box
> volume between .75 and 1.5 cubic feet,
> without adding any mass to it.

> But to keep these really budget, I'd go with
> the 8" long, 1.5" diameter vent
> and .75 cubic feet.

[Pete Schumacher ®]

> I need to copy the published specs into a
> box calculator and model this. Pressed for
> time right now, though, so just asking for a
> ballpark idea on box volume and expected f3.
> Probably looking at a lower Q alignment
> (around 0.5?), to reduce LF boom.

A stuffed, sealed box of between .5 and 1 cubic foot will work fine, with F3 right around 50Hz. You won't have much peaking in the sealed box, it's the vented one you need to be concerned about. Besides, it's a LOT easier to integrate a sub with a sealed box.

[brianp]

That's what I like to hear. I prefer the tighter bass of sealed enclosures anyway. Now, what is the optimum baffle size for the BSC in Eric's crossover to work properly?

> A stuffed, sealed box of between .5 and 1
> cubic foot will work fine, with F3 right
> around 50Hz. You won't have much peaking in
> the sealed box, it's the vented one you need
> to be concerned about. Besides, it's a LOT
> easier to integrate a sub with a sealed box.

[nepaeric]

My musical tastes and yours agree, Brian. Generally, I have a tendency towards a low Q, sealed enclosure, as opposed to the sometimes, "exaggerated," boomy low frequency of a vented enclosure. Not as low as 0.5, but in the range of 0.6-0.7. This is typical for acoustical music, jazz and classical tastes.

I merely suggested a reflex design to satisfy "most" listeners, who tend to put more emphasis on bass range and quantity. If you are like myself, and value lean bass quality, purity, depth and accuracy, you would like these in a 0.65 cu ft, sealed enclosure with about 8 oz. of stuffing, as Jim's was done. I must assume these are slightly on the lower side of optimum Qtc 0.707, which would provide the flattest response curve.

Typically the way to obtain a lower Q would entail the use of a slightly larger enclosure. If Pete is suggesting a volume of 0.5 - 1.0, I'd probably stick closer to the higher side of his recommendation, and stuff generously. One thing I'd probably do different, and be money well spent is use Mahogany Sound Acoustastuf, which has 16 bends per inch, in place of the Dacron polyester fiberfil Jim opted for in this extremely budgeted project. Although, nothing wrong with Dacron pillow stuffing from WalMart. Fiberglass is excellent, too, but can be an itchy mess. Just my opinions.

I haven't done the Math using T/S parameters on this for a Q of 0.5, but I'd imagine it'd be close at 1.0. You might even have to build it slightly bigger.

Pete, please chime in on this.

Best Wishes,
Eric

[Pete Schumacher ®]

> That's what I like to hear. I prefer the
> tighter bass of sealed enclosures anyway.
> Now, what is the optimum baffle size for the
> BSC in Eric's crossover to work properly?

9" wide baffle.

He's building a floor stander. But a small monitor box, maybe 16x9 inches would be excellent.

[Wolf]

Both below and above .707 Qtc, the F3 rises. The larger the box, the higher the F3 will be, as well as becoming too loose at the lower frequencies. As long as a sub is used, it isn't a big deal.
Later,
Wolf

[Pete Schumacher ®]

There's one advantage to building on the smaller end of the scale, and that's excursion control below system resonance. If the box is too large, then the woofer doesn't have that nice air spring to keep it under control. I built the Quad DA175 Schumakubin in a sealed box, 2 cubic feet, or .5 cubes per woofer. It was also stuffed with fiberglass batting, but not overly dense, with open air space behind the woofers. The bass quality is quite nice that way. Just ask Rudy Jakubin.

As Wolf said, anything other than Q = .707 and F3 rises. And as he also stated, if you're using a sub, it won't make a big difference either way, especially if you're high passing the DA175 between 60Hz and 80Hz

[nepaeric]

would be ideal for a DA-175 for Brian, who values lean, quality bass with a low Q of 0.5 ? I'm interested in his progress, and wondering if he'd find happiness in a 0.65 box like Jim's "Mosers?"
Would he be better off with one like the one we built, bigger, or smaller.

I actually might consider building a pair of these, myself, as I've been exceptionally impressed with the results, especially considering thier modest cost, and simplicity of build. I'm jealous of Jim.

Warm Regards,
Eric

> There's one advantage to building on the
> smaller end of the scale, and that's
> excursion control below system resonance. If
> the box is too large, then the woofer
> doesn't have that nice air spring to keep it
> under control. I built the Quad DA175
> Schumakubin in a sealed box, 2 cubic feet,
> or .5 cubes per woofer. It was also stuffed
> with fiberglass batting, but not overly
> dense, with open air space behind the
> woofers. The bass quality is quite nice that
> way. Just ask Rudy Jakubin.

> As Wolf said, anything other than Q = .707
> and F3 rises. And as he also stated, if
> you're using a sub, it won't make a big
> difference either way, especially if you're
> high passing the DA175 between 60Hz and 80Hz

[Pete Schumacher ®]

> would be ideal for a DA-175 for Brian, who
> values lean, quality bass with a low Q of
> 0.5 ? I'm interested in his progress, and
> wondering if he'd find happiness in a 0.65
> box like Jim's "Mosers?"
> Would he be better off with one like the one
> we built, bigger, or smaller.

> I actually might consider building a pair of
> these, myself, as I've been exceptionally
> impressed with the results, especially
> considering thier modest cost, and
> simplicity of build. I'm jealous of Jim.

> Warm Regards,
> Eric

But use fiberglass. It actually does lower system Q better than Acoustastuf or Dacron fiber can.

If you stuffed a .75 cubic footer, the system Q would very likely be .6 or less.