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Purveyor; a dynamite small 3-way with concussive tendencies....

Wolf

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Now that InDIYana 2022 is post-op, I figured I post the details to this little marvel that impressed quite a few last weekend.
The name is appropriate, as Purveyor means to "provide what is required or necessary".

Goals:

  • Use a 0.23ft^3 knock down cab with a 3-way. This meant very careful driver selection, and a W-T/M orientation.
  • Make it easy to assemble for those with fewer tools. All but tweeters are surface mount.
  • Make it more affordable compared to most 3-way designs.
  • Yield great performance for the modest cost. All drivers have a magnetic shorting turn via a cap or ring.
  • Make a simplistic 3-way xover that is easy to assemble and would fit in the box with all of the drivers.
Drivers:

  • Peerless SLS 5" P830945; This is working in a 6 ltr net volume to produce F3/10 of 52/38. It also has higher sensitivity than ANY other 5.25" that can accomplish this bass extension feat. Being that, it has a lower Zmin above tuning at 150Hz of 2.3 ohms. This means the woofer lowpass coil has to be an air-core, and I was able to yield a Zmin of 2.6 ohms without speaker wires. This means it should be of a roughly stable 3 ohms by the amplifier sight, and a fairly stable 4 ohm load over all. It's a very minute area, and approaching 0 in terms of phase. Aluminum shorting ring, and long Xmax.
  • To accomplish this response in a small box such as this, there is no way you can use a port and tune low enough. It is just not possible. I was able to fit the SB Acoustics SB15SFCR-00 5x8" PR on the back of the cab. This involved using a midrange chamber of specific orientation to allow the PR to fit, albeit offset in one direction horizontally. 2x 0.5" x 1/8" thick washers and a stainless steel Allen-head M6x1 bolt were used to tune the PR to roughly 20Hz.
  • The Dayton Audio PC83-4 was used as the midrange. Being this is a 4 ohm driver, the xover landed at 650Hz to meld with the woofer to both keep impedance and xmax in check. Being the woofer is a 5.25", the off-axis response is really not impacted heavily. The tweeter and it landed at 5kHz, and the 83 has good enough off-axis response to make this just fine and keep the vocal range centered in the mid driver. The 83 also has a very benign breakup, likely due to its coated woven fiber cone, and it sounds fantastic. A decent xmax and copper cap keep it clean. 1 ltr sealed is all it needed, and this is a benefit here to give the woofer all the volume I could. (I used this midbass in the OSFA blue tooth speaker, and really liked its qualities. I also paired it with the following tweeter as a 2-way. I liked the results.)
  • The Dayton DSN25F-4 Designer Series 1" was chosen to finish off the top 2 octaves, 5k+. Paired with the PC83-4, the acoustic offset seems to be really similar, the CTC is small, and the frame is tiny. Sensitivity is 95dB, so it is heavily padded -13dB, and is loafing with a very easy living. On axis, there is a small rise at 12kHz of about 3dB, but most won't notice it. Just above the tweeter axis about 15* or +4", the rise disappears and the response is really smooth and flat. A copper cap keeps it clean. FF damps the Fs. Possible bonus? These tweeters have been known to be slightly leaky. If yes- then the midrange is in a slightly aperiodic box. If not- it does not impact the performance. Of note; I had a bad unit and PE replaced it. They are on back-order until July currently.
Place all into blender and pulse 3 times....

Xover points were 650/5k, not as pictured in the last sim-snap. I did not measure impedance and save it yet, so this should be close.
Xover board is 6" x 6.25". I ended up upgrading to the Cebo caps on the tweeters after the photo was taken. Much better, IMO.
Current prices:
P830945 = 36.98
PC83-4 = 12.98
DSN25F-4 = 18.98
SB15SFCR-00 = 35.70
Denovo 0.23ft^3 knock-down box = 26.98

Xovers as built: ~$115.20 each. I used the $4.00 75uF caps from ApexJr, and est a $1/resistor. The rest of the amounts are from Meniscus' website.

Total/cab comes to $247.14 including the cabinet, or $494.98; not bad for a compact 3-way! (My cost was $300 from discounts, salvaged upwound coils, used and free drivers, FWIW.) Most of the time, by the time you have xovers factored in with drivers on a 3-way, you're already in the $500+ category without even thinking about cabinets.
 

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JeffS7444

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That looks like a swell little "hooligan" that you've created! Wonder if my AVR can handle the impedance? Because my first thought is what an upgrade they'd be over my current L, R and Center channel speakers.
 

DWPress

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They look like a great compromise and a brilliant use of materials on hand - would love to hear them.
 

alex-z

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Excellent build for the price, I have some questions if you don't mind.

How does the tweeter behave if you cross it over at 4000 or even 3500Hz? I would assume this tightens up the vertical directivity but comes with a power handling compromise?

How loud do these play without significant compression or distortion?

Any chance of having Amir or Erin run them through the Klippel?
 
OP
Wolf

Wolf

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The tweeter is fine lower, to 3k or just below, but the drivers just did not tell me they wanted a lower xover point. A lot of times in a 3 way it works well with a 3 octave spread. I've done it with less, but they just came together here at 5k. The mid has really good off axis response to that point, so it should be fine.

I had them in the conference room Saturday playing loudly with no strain with Boxenkiller hitting them. It was in the 90 range at about 2m for the front row. They took it like champs.

The Dayton APA150 runs them fine, kicking on the fan at higher outputs. 2.65 ohms at 145 or so, and all else above there. As long as the receiver does 4 ohms at 100W/ch, you should be good.

I don't live close to either for a Klippel spin.
 

gab

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Ben - How do you like the Purveyor compared to your 2 way Fenrir design from a few years back?
 
OP
Wolf

Wolf

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Kinda hard to compare as they are 2 very different designs with 2 very different sets of goals.
That said, the Fenrir had a small peak at the top end of the woofer due to the directivity change to the 3/4 waveguide tweeter. It was fairly benign, but I could hear it, and it bothered me.
The Purveyor have better midrange clarity and I feel the bass is better controlled.
 

DWPress

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Whereabouts in Michigan are you?
Northern, about 5 hours north of Detroit. I'd love to hear them but actually have no use for them though I'm sure I could set up a 3rd system somewhere if hard pressed. ;)
 
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Wolf

Wolf

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Northern, about 5 hours north of Detroit. I'd love to hear them but actually have no use for them though I'm sure I could set up a 3rd system somewhere if hard pressed. ;)
That's a bit far for a weekend listen, but I was not offering for sale or anything. Just thought you might be close enough to get a listen.
 

restorer-john

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The design is realy cute. Reminds me of a bunch of similar layout shaped front baffle, compact designs in the 1980s.
 

DWPress

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@Wolf I'm just fond of horizontally implemented designs. You could fit 6 of yours in one of mine. ;)


IMG_0613.JPG
 

D!sco

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Very nice! Do you have a guess at the max SPL? Love the form factor.
 

D!sco

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Taxi.gif

Yup!
I figure in nearfield I could deafen myself with these pretty easily @Wolf. What about, say, 3m?
 
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Wolf

Wolf

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If you're playing stuff like Boxenkiller, then the example I gave before is about it. 90dB at 2m, but that cut really kicks hard. I could tell they were really moving, even if I didn't smack the backplates of the woofers.

I've had them in my living room setup, 8-9' distance mostly, and they can really get loud- if power is at the ready. The APA150 I would call the minimum power requirement, or 75W x 2. At half volume (12-noon) running single-ended from the Anthem AVM30 pre amp (-15 on the dial), the APA will get the fan turned on at higher outputs. That said, the Purveyor are really clean HD-wise and you don't realize how loud this actually is.

I need to get the spl-meter out for a trial and see, C-weighted and slow with peak hold, yes- with earplugs, and hook up the Crowns.

I'll let you know...
 
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Wolf

Wolf

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With the APA, 90dB with gain at 12 noon seems to be onset of higher amp thd. Still pretty LOUD!
I'll test more later...
 

Somafunk

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Very smart looking, The form factor reminds me of my LYD 48’s
 

D!sco

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The flake lends to the "low rider" look. EQ them to bounce up and down and you'll be set.

Great work dude
 
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