Peerless 830656 and Denovo Mini Elliptical. Man it's ugly.

[ryanbouma]

Hey guys,

I've been working on some designs to help out Erich over on DIYsound Group. Figured it's worth posting here to raise awareness for the great stuff he's selling over there. A good guy for the hobby.

This little build really blew my mind. I was not expecting so good. There aren't many MTs at less than $100 that can touch this. The Denovo stuff is really killer.


Here we go



Uses the Denovo Mini Elliptical and the Peerless 830656. That's an 8 x 12" baffle. Depth is your choice. PM me if you'd like some suggestions on box alignment. I'm using 10" deep and sealed and crossed to subs at 90hz. Sounds right. Erich may CNC some flat packs for these.

This scores a 8/10 on the ugly scale, even if I finished it nice. The reason it isn't a full 10 ugly, is the peerless cone is nice, and it's really small. But it's worth building imo, because it's cheap, small, and VERY easy to build if someone doesn't have good tools. The key is everything can be surface mounted. Please, build some grills

Here are the measurements.

Speaker 1

http://i874.photobucket.com/albums/a...ssandmini1.png

Speaker 2

http://i874.photobucket.com/albums/a...ssandmini2.png

XO Schematic



Nice and cheap and simple. I would not bother with the optional notch on the tweeter, unless you have very sensitive ears in the 5khz range and don't care about the extra $. It's there if you need it. Buy a 4 and a 5ohm resistor and try both. 4ohms is likely better. Might be a good idea to put 2 4ohm resistors in parallel for the 2ohm tweeter resistor. PM me if you want me to help you assemble cross overs for you.

Complete MEASUREMENTS

On axis and power compression



That's 2.83V and +18db. Barely a 1/4db difference. Not bad. My gating doesn't show below 250hz, which is likely where it would compress the most. Good response too.

Horizontal 0, 15, 30



30, 45, 60



Vertical below 5, 15, 30



Vertical above 5, 15, 30



I'm pleased and going to stop here. I don't know what I'd change in such a budget build. This turned out much better than I expected.

Use these as budget surrounds if you can point them down at you. The lobe points up a bit. If you can't, then flip them upside down and listen that way. These would be good on a desktop also. Heck, even mains if you can't afford to step up to something else. Do yourself a favour and build some grills though

ACTIVE SETTINGS (Just in case)

Woofer
Butterworth 6db/oct low pass at 1500hz
Level = 0db
Delay = 0.1mS
EQ 1 = 900hz, -2.5db, q = 1.8
EQ 2 = 2500hz, +3db, q = 1.0
EQ 3 = 6000hz, -18db, q = 2.0
EQ 4 = 10,000hz, -12db, q = 2.0

Tweeter
Linkwitz-Riley 12db/oct high pass at 5250hz
Level = -16db
Delay = 0mS
EQ 1 = 5500hz, -2.5db, q = 1.0
EQ 2 = 3000hz, +6db, q = 2.7
EQ 3 = 1950hz, -4db, q = 3.0

If anyone tries the active, please let me know. I might get to it, but kinds of doubt it.

Thanks for looking.

[mike1001]

Hey guys,

I've been working on some designs to help out Erich over on DIYsound Group. Figured it's worth posting here to raise awareness for the great stuff he's selling over there. A good guy for the hobby.

This little build really blew my mind. I was not expecting so good. There aren't many MTs at less than $100 that can touch this. The Denovo stuff is really killer.


Here we go



Uses the Denovo Mini Elliptical and the Peerless 830656. That's an 8 x 12" baffle. Depth is your choice. PM me if you'd like some suggestions on box alignment. I'm using 10" deep and sealed and crossed to subs at 90hz. Sounds right. Erich may CNC some flat packs for these.

This scores a 8/10 on the ugly scale, even if I finished it nice. The reason it isn't a full 10 ugly, is the peerless cone is nice, and it's really small. But it's worth building imo, because it's cheap, small, and VERY easy to build if someone doesn't have good tools. The key is everything can be surface mounted. Please, build some grills

Here are the measurements.

Speaker 1

http://i874.photobucket.com/albums/a...ssandmini1.png

Speaker 2

http://i874.photobucket.com/albums/a...ssandmini2.png

XO Schematic



Nice and cheap and simple. I would not bother with the optional notch on the tweeter, unless you have very sensitive ears in the 5khz range and don't care about the extra $. It's there if you need it. Buy a 4 and a 5ohm resistor and try both. 4ohms is likely better. Might be a good idea to put 2 4ohm resistors in parallel for the 2ohm tweeter resistor. PM me if you want me to help you assemble cross overs for you.

Complete MEASUREMENTS

On axis and power compression



That's 2.83V and +18db. Barely a 1/4db difference. Not bad. My gating doesn't show below 250hz, which is likely where it would compress the most. Good response too.

Horizontal 0, 15, 30



30, 45, 60



Vertical below 5, 15, 30



Vertical above 5, 15, 30



I'm pleased and going to stop here. I don't know what I'd change in such a budget build. This turned out much better than I expected.

Use these as budget surrounds if you can point them down at you. The lobe points up a bit. If you can't, then flip them upside down and listen that way. These would be good on a desktop also. Heck, even mains if you can't afford to step up to something else. Do yourself a favour and build some grills though

ACTIVE SETTINGS (Just in case)

Woofer
Butterworth 6db/oct low pass at 1500hz
Level = 0db
Delay = 0.1mS
EQ 1 = 900hz, -2.5db, q = 1.8
EQ 2 = 2500hz, +3db, q = 1.0
EQ 3 = 6000hz, -18db, q = 2.0
EQ 4 = 10,000hz, -12db, q = 2.0

Tweeter
Linkwitz-Riley 12db/oct high pass at 5250hz
Level = -16db
Delay = 0mS
EQ 1 = 5500hz, -2.5db, q = 1.0
EQ 2 = 3000hz, +6db, q = 2.7
EQ 3 = 1950hz, -4db, q = 3.0

If anyone tries the active, please let me know. I might get to it, but kinds of doubt it.

Thanks for looking.

I'm new at this but should the l,c,r in your notch filter be wired in parallel?

[ryanbouma]

I'm new at this but should the l,c,r in your notch filter be wired in parallel?

The optional one? It's right. If you wire them in parallel they act independently. Should be series.

[mike1001]

The optional one? It's right. If you wire them in parallel they act independently. Should be series.

i must be confused, it looks like you have a resonance filter on your tweeter?
just wondering why you would do this.

notch filter
http://www.mh-audio.nl/parallelnotchfilter.asp

resonance filter
http://www.mh-audio.nl/RLC_Series_Re...Calculator.asp

[ryanbouma]

I see your confusion. Those links don't describe notches/traps/tanks/RLC very well. Basically, the type of notch I'm using is more effective than something wired in parallel, but in series with the driver. But the downside is impedance drops at the notch. So you either have to use this type in the stop band of the driver filter, or have a high R value. I have both in this case. You can also use this type of notch on woofers. It's actually more typically used on woofers to supress break up. Some of the confusion may be that I'm not using that type of notch in a very common way.

The type of RLC I'm using can also be used as impedance compensation around the tweeter Fs. Instead here I've used a 2ohm R in parallel with the tweeter. This flattens the impedance very nicely. Normally you can't do that, but in this case there is such a huge sensitivity difference between my tweeter and woofer, that I can.

Does that make sense? I can try and find some better links if I've confused you.

[mike1001]

i get it now, like this:
http://www.diyaudioandvideo.com/Tutorial/Crossover/