Trace Elliot Bright Box Question

[DiMarco]

Hi Quentin,

On tuesday I'm practicing with the band and will bring the brightbox home with me to see if I can get all the details on that filter circuit. Basically it is a simple high pass filter that supposedly kicks in from 4kHz onward thus filters out anything underneath that frequency. This works great with the 2x15 cab as that runs up to around 4 to 4.5kHz.

I suppose depending on which midrange 5" speakers you choose to utilize you can use any generic high pass filter at 4kHz for a custom brightbox. Just make sure the midrange speakers you choose can deliver tone up to around 8kHz and are loud enough. I am quite happy with the Celestions I chose as they don't cost a lot and handle the job pretty well. The brightbox gives me the extra definition I was missing by using just the 2x15 cab. If you spend a little more you can find speakers that are a bit louder and can handle 10kHz. though.

[deepbass5]

I have to say having owned one of these when i had a trace 2 x 15" rig. I feel It never made any difference at all and I was kidding myself it did. The fact that my 15's had bullets as well they were brighter than the brite box.
In conclusion the 2 x 8" powered Peavey brite box I sold to get it was better. So I would agree with Bill.
It was that old green photo advert that apeared on the back of so many bass mags that made us believe we needed one.

[DiMarco]

Ow but in my cass it makes a LOT of difference! Mainly more clarity when using my active Warwick, EBMM and Fender Marcus Miller jazz. It does make sense since anything higher then 5kHz goes MIA without a hf unit or brightbox.

If your instrument doesn't produce any usable noise in the treble range you won't need a brightbox or hf unit in your cab. This is perfectly alright and can sound great too. I was looking for more of the clicketyclack when slapping though and am perfectly happy with this brightbox solution.

[ximaipa]

Thanks DiMarco,
That would be great. Thanks
Quentin

[ximaipa]

Hi [color=#282828][font=helvetica, arial, sans-serif]DiMarco,[/font][/color]

I was wondering if you think the [url="http://www.ebay.com/itm/Trace-Elliot-Acoustic-Design-Loudspeaker-Set-Of-4-Amp-Speaker-Quad-8-Ohm-/261405293682?pt=LH_DefaultDomain_0&hash=item3cdcf83c72"]Trace Elliot Acoustic Design Loudspeaker -- Set Of 4 [/url] British Audio has for sale on eBay and their site would work for the brightbox?

I also tried to diagram the cross over from your photos to see what it how it works. I can make out the spec for the capacitors but the resistors were to small to read. I'm pretty sure I can fabricate a cross over. I'm hoping you can help me with a wiring diagram of how the input connects to the board and how the speakers are wired. Also the size of the resistors. Thanks for any help you can provide.

best,
Quentin

[DiMarco]

Hi Quentin, I was meaning to respond sooner but last week didn't get round to checking the filter circuit board. Will do so somewhere this week.

The speakers British Audio have for sale are from an acoustic guitar amp. I am not sure if they will work in a brightbox design where you want the speakers to reach up to 8kHz or more. I have no specs on the speakers you mentioned here...

[stevie]

I remember the original Brightbox speakers having rubber, not foam, surrounds. They were purely midrange drivers with a phase plug in the middle. They stopped making them last century. I expect any decent quality 5" PA midrange would do a similar job. Bass/midrange or hi-fi drivers are unlikely to be sensitive enough.

Edit: I obviously missed the photo of the original drivers on the previous page.

Edited February 24, 2014 by stevie

[ximaipa]

Hi DiMarco,

Thanks, any info will be greatly appreciated.

I'm going to go with the [color=#282828][font=helvetica, arial, sans-serif]Celestion speakers you used. Shane from British Audio said the Acoustic speakers they have for sale would not be a good choice. He also said that [/font][/color]there were never drawings made for any of the Trace cabinets so no schematic as per the wiring and crossover.[color=#282828][font=helvetica, arial, sans-serif] [/font][/color]

[color=#282828][font=helvetica, arial, sans-serif]best,[/font][/color]
[color=#282828][font=helvetica, arial, sans-serif]Quentin [/font][/color]

[stevie]

It would be interesting to know what the crossover is supposed to be. The picture of the x-over earlier in the thread shows four 100uF 40V *polarized* electrolytics and two diodes. That's a weird configuration. I wonder if somebody has changed the caps at some time (from bipolar).

[DiMarco]

Here are photos of the filter circuit in higher resolution. Sadly I do not know much about electronics or filters so I hope someone can see what the filter configuration is supposed to do.

Simle logic dictates a simple high pass filter at around 4kHz should work just fine, a filter doesn't need to be exactly the same as this original Trace Elliot one. It just needs to cut off the lows.

[DiMarco]

Ow it seems the forum software automatically resizes images while you upload them. Smart! But in this case not so handy. I don't think the images will become much more clear then this though.

[ximaipa]

Thanks DiMarco. I've done some reading up on high pass filters and speaker wiring. Do you know if the speakers are wired in series or parallel. My guess is [b]Wiring Configuration for 4 Speakers in Series/Parallel[/b] to keep the 8 ohm load? best, Quentin.

[DiMarco]

Exactly.