Lotus BVR/CHR-70 - Question about suitability

[planet10]

1/ length of your port slot piece is 18mm too long (the entire passage is 76.2mm)

otherwise looks perfect.

dave

 

[BL21DE3]

Hi Dave,

Cheers for taking the time to check my measurements over and pointing out my error.

Regards,
Ewan

 

[Ty_Bower]

Well, no FR based system is ideal for the kind of material you favour; OTOH, I'm often to be found listening to the same myself, so providing you accept the limitations in advance, you should be fine.

May I ask what kind of system is ideal for the favored material? I have a genuine interest here - I suspect my music preferences are similar, and I'm currently experimenting with full range speakers myself.

 

[Scottmoose]

From my POV, if it's heavy material with huge LF dynamic swings etc., and we're talking 'ideals' then multiple sealed or EBS 15in - 18in HE woofers per channel with wide-band compression mids & tweeters, the mids covering as a minimum 500Hz - 4KHz. Active XOs, efficiency and headroom of all as high as possible without sacrificing everything else on its alter, potential for handling 120dB dynamic peaks at the listening position across the entire audio band.

 

[Ian444]

You could also consider building Lotus' fraternal twin, Coniston. The EL70 will give at least the equivalent of doubling the amount of power you have on tap vrs the CHR-70

Dave, is this due to the increased efficiency of the EL70, the Coniston box, or both? The specs say only 1.5 dB difference between CHR70 and EL70. Maybe you have measured more difference than that?

Ian.

 

[planet10]

I was guessing on the 3 dB, measures put CHR just over 82, EL70 just over 84, so less gain than i'd estimated.

dave

 

[Ian444]

Thanks Dave, still, its something to keep in mind and nice to know, the 2dB diff.

 

[BL21DE3]

Quick question for Dave et al. If I were to use a stepped deflector at the base of my Coniston to add some additional mass, would it be possible to use MDF to construct this? (I vaguely remember the design sheet for a 'spawn' variant mentioning that you could use MDF for the stepped deflectors)

Regards,
Ewan

 

[planet10]

I don't think MDF would be a hardship in this application. The extra mass won't hurt. I would slice the top off with a standard angled deflector.

dave

 

[BL21DE3]

Thanks for the reply Dave. I have already decided on slicing the top of the cabinet and using the standard deflector to remove some of the mass from the top.

With regards to a stepped deflector is there a rule of thumb for the layout of the stepped deflector in a Coniston or is it a case of getting the steps to follow the front edge of the angled deflector as closely as possible? I know on the spawn family i.e G Chang the sheets mention that the 'steps' begin half a material thickness back from the front and then each subsequent step is a material thickness shorter.

Regards,
Ewan

 

[planet10]

How big the step is depends on the deflector angle... the above is for 45 degrees, attached for Coniston using 3/4".

dave

 

[BL21DE3]

Thanks for the image Dave, it should help me work out the dimensions of my deflector.

Regards,
Ewan

 

[AlejandroR]

Dave, is this due to the increased efficiency of the EL70, the Coniston box, or both? The specs say only 1.5 dB difference between CHR70 and EL70. Maybe you have measured more difference than that?

Ian.

Is it possible to use the EL70 in the lotus ?. Considering it is smaller than the Coniston, ha have more chances to use it in my living room (WAF)

 

[Scottmoose]

No. Otherwise I would have saved myself the effort. 😉

 

[AlejandroR]

No. Otherwise I would have saved myself the effort. 😉

OK, I will go with the Coniston, and don't tall my wife the size 🙂

 

[Scottmoose]

Just explain to her that they grew, like mushrooms.

 

[italynstylion]

I honestly doubt she'll notice the difference. They look identical (and beautiful) so they should really be fine.

 

[AlejandroR]

I honestly doubt she'll notice the difference. They look identical (and beautiful) so they should really be fine.

My wife is only 3" (7 cm) taller than the Coniston and 10" (25cm) taller than the Lotus, so she will notice 🙂 . Anyway, I need the extra power of the EL70 because I use an 8 watts S.E. EL34 power amplifier so I think the CHR-70 will not give enough volume.