System Pictures & Description

[ahegyes]

Interesting stuff JamesTRexx. What about finishing them??? Do you want to paint them, or veneer them???

[JamesTRexx]

Originally Posted by ahegyes

Interesting stuff JamesTRexx. What about finishing them??? Do you want to paint them, or veneer them???

What I have in mind is covering the tweeter and mid baffle with felt, and also the inside behind it which needs it as it sounds like a box despite open sides.
The frames will be painted in high gloss white which should be less intrusive to sight. Thought about black but that'll give the whole room a darker feeling.
All this after rounding all edges, and I'm not sure when that'll be done because it'll mean no playing music for 1 or more days, and the thought gives me withdrawal symptoms.

[SAC]

A somewhat unique design of popular combinations of drivers. 3-way active driven by class D amps.
4x alpha 15a - paralleled to give 2x4ohm, 6dbLP@67Hz
2x Visaton B200 - 2x6ohm, 6db@300&600HZ (plus unusual magnet mount)
2x Neo3 PDR, open backed, 2x4ohm, 6db@1500Hz

Uses two layers of baltic birch for strength/rigidity. The fabric over the woofers does a lot for WAF!!!

The passive line level crossover (PLLXO) is awaiting a box. It is connected to three stereo power amps. PLLXO's do not see much mention in the forums but are considered ideal in many ways it seems.

I have no measuring equipment. Sounds smooth on 31 octave test tone tracks. Sub- bass is missing for movies at least and the top end is a bit bright.

The sound? I am very happy with the realism and the detail. Would recommend it to others.

[SAC]

Here is the magnet mount (believe it or not) and the yet to be boxed PLLXO. Please excuse the mess with speaker cabling and the like. It's been like this for months now but I am too busy enjoying the sound.

[SimontY]

Very interesting set of speakers!!!

[planet10]

SAC,

Interesting speaker. I see you have phase plugged the B200... have you played with a higher XO? I've not played with the BG, but i seem to recall that it would prefer to cross higher, that could be part of the issus with "a bit bright". The plugged B200 is quite capable of going higher,

dave

[paulspencer]

SAC, is that some kind of glue on the outside of the basket for damping? It's something I've thought many times, that (especially in open baffle) a driver would benefit from absorbing material inside the basket.

[navin]

Originally Posted by SAC

3-way active driven by class D amps.
4x alpha 15a - paralleled to give 2x4ohm, 6dbLP@67Hz
2x Visaton B200 - 2x6ohm, 6db@300&600HZ (plus unusual magnet mount)
2x Neo3 PDR, open backed, 2x4ohm, 6db@1500Hz

The passive line level crossover (PLLXO) is awaiting a box. It is connected to three stereo power amps. PLLXO's do not see much mention in the forums but are considered ideal in many ways it seems.

Sub- bass is missing for movies at least and the top end is a bit bright.

The sound? I am very happy with the realism and the detail. Would recommend it to others.

With the Visaton being HPed at 300Hz and the Alphas being LPed at 67Hz is there not a hole in the midbass?

Sub bass is a problem with most OB systems. Maybe using Hawthorne Auggies would resolve this.

[SimontY]

Navin,

If you look at the frequency response of a woofer on an OB with no correction or filters applied there's a large peak in the range he's "missing" via his XO. I roll mine in from about 80hz or something and that makes it more or less flat and smooth at the listening seat!

Simon

[SAC]

Thanks all for your interest. These have been a long time in the making and it is nice to share thoughts at last.

Paul,
The “glue” is “Plumbers Mate” sold for sealing minor pipe gaps and such jobs. It is recommended for the reported basket ringing of the B200.

For the magnet mount, I used a metal to metal glue to attach the magnet to a piece of aluminium, which in turn bolts on to a second sheet which is bolted to the baffle.

Dave,
I keep changing my mind about the tweeter crossover. Yes, a 6db@8KHz was used for a while and sounds much flatter. However, I have returned to the previous low crossover which the Neo3 is more capable of with the back cup removed than with it on. Perhaps I enjoy the brightness in the absence of reverberation. The room is open to the rest of the house on one wall which robs the reverberant atmosphere I seek. I am speculating mind you.

It is still a work in progress really.

Navin,
PLL filters are supposed to be effective in theory only, and actually somewhat weaker I hear. Also the Alphas are supposed to rise in response soon after 67Hz with a hump at one point, so the actual response is what my test tones indicate, that it is flat in the mid bass and blends well with the B200. I see Simon just indicated the same idea.

Also, Hawthorne sells modified alpha15s under his own brand name, although I do not recall if the Auggies are one of those. Either way, in the UK they are too expensive for me to bother importing.