Not just another speaker build.

[Fatmarley]

"I often think up speaker designs and then change my mind, so this isn't set in concrete, just my rambling thoughts..."

all part of the iterative process, a good thing. Set in concrete, not so good

I wouldn't mind, but it's all the money I've spent on drivers over the years, and then sold at a loss!

 

[James]

Parallels?

Possibly. I'm grappling with excuses to mask my complete lack of interest actually, such is the satisfaction with my hifi these days.

I've designed and built most configurations, including 2-ways, 2.5-ways, 3-ways, ported, sealed (mostly), stand-mount, floor-standing, open-baffle, passive, active (semi), narrow baffle, wide baffle, boundary-coupled woofers, large boxes (100L+), mini-monitors (9L), in-between sizes, traded with Hoffman's Iron Law, and now there's not much more to do.

 

[Mike Hanson]

Possibly. I'm grappling with excuses to mask my complete lack of interest actually, such is the satisfaction with my hifi these days.

I've designed and built most configurations, including 2-ways, 2.5-ways, 3-ways, ported, sealed (mostly), stand-mount, floor-standing, open-baffle, passive, active (semi), narrow baffle, wide baffle, boundary-coupled woofers, large boxes (100L+), mini-monitors (9L), in-between sizes, traded with Hoffman's Iron Law, and now there's not much more to do.

After all that, what did you settle on--which was your favorite?

 

[James]

After all that, what did you settle on--which was your favorite?

That's is like asking which is your favourite child. They all have different strengths and weaknesses. I have chosen to keep the 3-way floor standing E-IIIR, 2-way mini-monitor E-IX and wide-baffle E-Xs. But I wish I kept the 2.5 way SBL-destroying E-IV, and Sonus-faber tribute E-VII. These are my fabulous five.

 

[Mike Hanson]

Well as least I've got one of those in my own system (the Ergo IX), and am about to begin building another of your designs, the PFM Special.

 

[Fatmarley]

The cabinets are finished, and I've had a quick listen to the first iteration of the crossover today. If it's anything like previous builds, there will be quite a number of iterations...

From left to right -Faital Pro 6RS140 midrange, Wavecore TWO30WA12 Tweeter, and Eminence Kappa 12A woofer.

12mm and 18mm plywood sheets.

Marking up driver holes in the baffle.

Cutting holes with a router and circle jig.

I used biscuits to join the baffle to the top, bottom and sides. Not for strength, just to stop the panel sliding about when glueing up.

When I found there wasn't much PVA glue left I decided to use PU18 viscoelastic glue instead. It's very messy and gets everywhere, but should help reduce vibrations.

The front panel is a sandwich of plywood with PU18 in-between to produce a constrained layer damping panel. I would have liked to have done the whole cabinet this way, but it would have made them far too heavy.

Port hole cut.

Bracing stuck in with more PU18.

2" acoustic foam and Monacor MDM-3 wool stuffing, also a bit of Dynamat type stuff on the side walls. Wool felt about 10mm thick.

Roundover the front edges with the router table.

 

[Fatmarley]

Starting the mid enclosure.

The tube with holes is exhaust pipe. The idea is to let the driver breath, but not let any sound out. It worked very well with a Scanspeak 25W 8565, but not so great here. I put my ear up to the hole while playing pink noise, and you could still hear sound. Maybe with the high pass filter it would have been ok because it was more of a deep rumble. According to the impedance it was acting as a port, whereas the one I used in the Scanspeak didn't have the double impedance peak. In the end I just filled the enclosure with wool toy stuffing material.

I used the circle jig to cut the hole for the mid driver and used my router freehand to finish the odd shape.

The panels will slip with just weight on top, so I fired a couple of pins in to keep them steady.

Finished! (in faux leather)

 

[Fatmarley]

I would have preferred them without the narrow top section, but it was purely because the diffraction looked better.

 

[James]

Fantastic work! I like the skunk-stripe aesthetic. I admire your confidence routing freehand the rebate for the Faital mid. The one and only time I used a non-circular driver (PHL mid), I used a chisel and took plenty of time paring by hand and test fitting as I went.

 

[Fatmarley]

Fantastic work! I like the skunk-stripe aesthetic. I admire your confidence routing freehand the rebate for the Faital mid. The one and only time I used a non-circular driver (PHL mid), I used a chisel and took plenty of time paring by hand and test fitting as I went.

Thanks James. It matches my PlayStation 5 (black & white).

I just took my time with the hand routing, and I think it worked out great.

 

[James]

It looks just like factory-made. I'd be interested to hear what you make of the Faital Pro 6RS140. Does it have a particularly smooth FR over is recommended range of up to 6kHz?

 

[Fatmarley]

Does it have a particularly smooth FR over is recommended range of up to 6kHz?

Not as good as I'd hoped.

 

[James]

That is a shame. The break-ups can probably be tamed with a couple of notch filters, but the lumpiness in the middle would be harder to deal with without resorting to EQ. I had a similar challenge with the PHL mid I used in my 8th design, that I never got quite right.

It just adds to the character of the loudspeakers, I guess.

 

[Salamander]

Those speaker cabinets look great, well done.

 

[Fatmarley]

Those speaker cabinets look great, well done.

Thank you.

 

[awkwardbydesign]

I've not been watching this build, but I have some questions/observations.
Is the exhaust pipe thing a kind of Variovent?
Troels Gravesen used shaped front panels on his Jenzen designs to tame midrange peaks.
And you can buy "real" leather fabric, such as I use. I am using dark brown on my current build, but black and other colours are available. https://www.ebay.co.uk/itm/25234523...d=link&campid=5338728743&toolid=20001&mkevt=1

 

[Fatmarley]

I've not been watching this build, but I have some questions/observations.
Is the exhaust pipe thing a kind of Variovent?

It's meant to act like a vehicle exhaust or muffler. As I said it worked great with another driver, but I did it differently then. If I stuffed the pipe, then it would act more like a variovent.

 

[Fatmarley]

Troels Gravesen used shaped front panels on his Jenzen designs to tame midrange peaks.
And you can buy "real" leather fabric, such as I use. I am using dark brown on my current build, but black and other colours are available. https://www.ebay.co.uk/itm/25234523...d=link&campid=5338728743&toolid=20001&mkevt=1

Before I started I played around with diffraction software, and that shaped baffle should give a peak centred around 1khz, but instead there's a dip. There is a peak centred at 1khz in the free air impedance measurement, so perhaps it's just inherent in the driver response. The other possibility is the chamfer on the back of the driver baffle. I know a lack of one can cause problems in that area. I had to pack the driver up about 4mm, so It may be worth removing the driver and doing some experiments...

Real leather's nearly three times the price!

 

[Fatmarley]

Here's the 1mtr frequency response measurement of mk1 crossover. It's good down to 200hz. Not sure why there's a dip at 330hz. (The red line is with the tweeter polarity reversed).

 

[awkwardbydesign]

Real leather's nearly three times the price!

But it's 3 times as good!