Fast, fun, Inexpensive OB project

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Nice build Pieter! As John said, I hope you can keep them.
If you feel the 100-200 region is a little recessed, that might be room placement. Of course there might not be any practical placement in your room that would fix that. It’s a range where many speakers actually have bloat.
 
hello John,

Thanks for sharing the speakers to the diy community. Im in the process of getting all the required parts and I cant wait to build the speakers.

Will the manzanita ultra with 15 grs and tc9fd work without the stands? Im thinking of putting them on the floor and just angled up facing the listener. If it wont work whats the minimum height of the stands needed?

thanks
 
Tubo....

Thanks for your interest in building the Manzanita! I designed it for stand mounting as you know.... the primary reasons were to limit floor bounce in the 100-400 Hz. region, get the tweeter up to a seated listener ear level and limit the overall size of the basic system to make it as flexible as possible in smaller environments.

With all that said, you can place the Manzanita on the floor if you wish. When I have experimented with that I found the tonal balance suffered, imaging-sound stage was much reduced and mid bass muddied up.

What is nice about this speaker, if it doesn't work on the floor, you can always add stands. 12" stand will help, 18" is better.

Good luck with your build and please let us know how your floor position works out.
 
silasmellor....

This is an often ask question... yes you can make a floor stander version if you wish.... Some adjustments to the crossover may be required to retain the original tonal balance and sonic character of the design.

On the plus side efficiency will go up a db or so, but most of that is in the mid bass region. And the stand mounted configuration seems to image a bit better. And you have a bit more material cost and wood working to do with the larger baffle stand assembly.

Once again, the speaker is designed to be flexible and if you don't like the floor standing version, you can always revert to the original design.... let's see, where did I put that saw.....

If you go forward with a floor standing version please let us know how it works out!
 
Thanks John, I already bought the parts (12” peerless version) including a selection of resistors to adjust with. Do you think other adjustments would be necessary? The speakers are for my dad, and the baffle will be built from some nice wooden tabletops he has surplus, so will almost definitely be floorstanders. I will post some photos when they’re built.
 
silasmellor I would just go ahead with the standard build, break them in for a few days and adjust to suite your room realities and personal taste. If you can't seem to get the speaker where you want it to be, then let me know and we can, in most cases, work it out. Look forward to seeing your build! Good luck!
 
Hi,

Yet another change to the Ultras. Took out the oil filled motor run capacitors and replaced them with the Daytons that John specifies in his build plans. The oil filled caps were used on the build as they were already in the parts bin and good sounding.

The oil filled caps are prettier and richer sounding than the Daytons and have a magic, organic midrange. The new caps are clearer in the midrange and are just more synergistic with these speakers. It sounds like the leading edge of the notes are more distinct now and that also helps.

Tightened up the bass, too. Neat trick.

It didn't transform the Ultras into something different but their balance is better. The oil filled caps are too laid back sounding in this mix.

The Dayton caps are still breaking in so it's a bit of a roller coaster ride as the sound changes every few hours. Fun ride. :D

Barry
 
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I started work on the baffles but I didn't mount the compression bit deep enough in the router collet and it actually started slipping out a bit. Fortunately, it made a rattling sound and I stopped my routing, but not before I noticed it had totally cut through the plywood when making the countersink! It just destroyed it.

So rather than buy a new sheet of birch, I ran to Lowe's today and bought their maple plywood. However, I noticed it was much lighter than birch. I could see the inner layers are pine. I noticed after the employee cut it down close to the proper size, there were some small voids along the edges. Is that going to be a problem sound wise? If it is, I can use the maple ply for some wife projects.
 
Is there any alternatives for the 15" GRS for us poor europeans? Or do we have to suck up the import tax and order from parts-express?

This one from Monacor is as close as it gets to be an alternative to the 15" GSR

SP-382PA


ForsideProdukterHøjttaler byg-selv PA bashøjttalere 15"
SP-382PA
15´´ højttaler
Varenr: 10.3320






899,00

Produkt informationTekniske dataDownloads
TEKNISKE DATA:
Impedance (Z) 8 Ω
Transmission method -
Frequency range f3-4,000 Hz
Resonant frequency (fs) 25 Hz
Rec. crossov. frequ. (fmax.) (12 dB/oct.) -
Power rating 150 W
Peak music power output 300 W
Sensitivity 94 dB/W/m
Max. rated SPL -
Max. voltage -
Radiation angle, horizontal -
Radiation angle, vertical -
Suspension compl. (Cms) 0.26 mm/N
Moving mass (Mms) 73 g
Mech. Q factor (Qms) 3.03
Electr. Q factor (Qes) 0.99
Total Q factor (Qts) 0.75
Equivalent volume (Vas) 270 l
DC resistance (Re) 7.0 Ω
Force factor (BxL) 10.87 Tm
Voice coil induct. (Le) 0.8 mH
Voice coil diameter Ø 50 mm
Voice coil former aluminium
Linear excursion (XMAX) ±3.5 mm
Eff. cone area (Sd) 825 cm2
Magnet weight 1.2 kg
Magnet diameter Ø 142 mm
Mounting cutout Ø 355 mm
Mounting depth 139 mm
Mounting hole diameter -
Hole spacing X-axis -
Hole spacing Y-axis -
Dimensions Ø 385 mm x 150 mm
Outside diameter Ø 385 mm
Width Ø 385 mm
Height -
Depth 150 mm
Protective class -
Admiss. ambient temp. 0-40 °C
Weight 3.9 kg
Sales unit 1
Type of speaker 15"
 
Hey Citronix, thanks for the update. I think i did have a look at that when hunting around but discounted it as having non-optimal Qts. In any case i went ahead and bought the 12" Peerless and will build the non-ultra Manzanita in a floor-standing version.



I wonder, what is optimal in terms of driver mounting, i see some people mount the woofers on the back, and some on the front. Is there any merit to making a rebate for the 12" or is that less important here? What about rebating the Vifa? I know its a pain, but i was thinking it might be an interesting exercise in template routing. I dont want to spend effort on it if its doesnt matter though...