Which plans for my CSS EL70's

[bobhowell]

I am looking at the many plans for this driver and trying to make a selection. I have two drivers, so am only looking at the single driver models.

This is for my 16'x12' man-cave with an old 30watt stereo receiver.

Mostly classical music at moderate levels.

I don't really understand the difference between a BVR and a simple bass reflex that I work out with Unibox. Then the Micro tower seems to be another whole approach. MK's mathcad sheets seem to replace Unibox for calculations. I don't have it.

The Derwent BVR seems to be my best fit and I started it but as I think about it I don't know the differences between all the approaches and it is time I work it out.

I heard Jim Griffin's Dual model in Atlanta and liked it, the short time I listened,but it seems best with dual drivers.

What comments or advice can you offer?

Thanks

Bob Howell

[CSS/XBL]

Originally Posted by bobhowell

I am looking at the many plans for this driver and trying to make a selection. I have two drivers, so am only looking at the single driver models.

This is for my 16'x12' man-cave with an old 30watt stereo receiver.

Mostly classical music at moderate levels.

I don't really understand the difference between a BVR and a simple bass reflex that I work out with Unibox. Then the Micro tower seems to be another whole approach. MK's mathcad sheets seem to replace Unibox for calculations. I don't have it.

The Derwent BVR seems to be my best fit and I started it but as I think about it I don't know the differences between all the approaches and it is time I work it out.

I heard Jim Griffin's Dual model in Atlanta and liked it, the short time I listened,but it seems best with dual drivers.

What comments or advice can you offer?

Thanks

Bob Howell

Hi,

Most of my listening has also been with 2 per side. Perhaps Dave, ChrisB or Scott could chime in.

Bob

[chrisb]

Originally Posted by CSS/XBL

Hi,

Most of my listening has also been with 2 per side. Perhaps Dave, ChrisB or Scott could chime in.

Bob

We do have a single pair in "milli-size" box (i.e. 4 litre vented), which I've listened to briefly, but until Dave gets around to loading a single pair into the latest 13 liter "X"-onken type enclosure, most of my listening has been with 2 per side as well (the castle micro-tower in this case).

I like 'em a lot - big, open soundstage and great detail from bottom to top, small square footprint, no stands required, fairly simple build, wire in series for a comfortable 8 ohm load.

[markaudio]

Hi Bob Howell,
Chris B's 4 litre idea could be interesting. Later, I'll post a pic of my 6 litre BR's I use at home. They've got CHR-70's in right now. I regularly swop with EL-70 as part of my test listening sessions.

Mark

[planet10]

Bob,

A bass reflex box is tuned fairly tightly. This means that as you move along the T/S curve the tuning can change from optimum to less than optimum. The dynamics of music are sufficient to do this not just turning the wick up.

The BVRs (and the miniOnken derived boxes) add the equivalent of a resitor in series with the port making them less sensitive to TS = f(V). The BVR then adds a horn load to the vent to improve the port's impedance matching with the air.

Done right you get a box with more finesse in the borrom octaves.

All that said, i have hypothesized based on what we have seen of measures of the MA drivers and what is measured for other drivers, is that TS = f(V) is much closer to a horizontal flat line than many other drivers.

The milli-sized box for the EL70 (4.5 litres) compromises potential bottom end to fit into a tidy LS3/5A sized box. I am very eager to listen to the full-sized prime boxes sitting downstairs awaiting drivers (EL70eN should be done later today or tomorrow)

dave

[bobhowell]

Thanks for the quick response. It will take a while to digest all this.Bob