Large Advent Line Level Baffle Step Compensation (BSC) Build Instructions

[Zimmer266]

Picked up the parts at Radio Shack today. I found this thread within three days of finding the original large Advents in a local used goods shop.

The find brought me right back to the days that my dad sold Advents, and I had stacked Epi 100s on top of 6003s. The ones that I picked up are the walnut version of the originals, and so far they are really nice.

 

[wiredbecker]

Cool thread Pete. Thanks!

 

[Pete B]

Thanks Chris, you might want to try the BSC box with the Econowave, I'm pretty sure that it will take it to another level.

 

[bhebbel]

I have a pair of Advent 5012/W speakers with bad woofs that I will be refoaming in the next week or so.

Thanks for the tip! I'll give it a try and you know the results.

 

[EastWest]

Hi Pete

Any chance you can help me figure out what to buy to build my own BSC? I've never done anything like this before.

I have a pair of 25th anniversary Advents with the soft dome tweeter. I keep them about 10 - 12 inches from the wall. I use a Marantz 2230 receiver. I plan to put the BSC between the pre out and the main in.

So, based on your instructions, I believe it would be best to building a 2.2k. at 4dB with no C1.

I have no idea how to search for the capacitors or resistors of these values or where to buy them.

I would appreciate any advice. Thanks so much!

 

[Pete B]

I don't check in here often, did you get help with finding parts?

 

[Stuart Pedaso]

Hi Pete

Any chance you can help me figure out what to buy to build my own BSC?

I plan to put the BSC between the pre out and the main in.

So, based on your instructions, I believe it would be best to building a 2.2k. at 4dB with no C1.

I have no idea how to search for the capacitors or resistors of these values or where to buy them.

I would appreciate any advice.

I can offer this list of parts that are currently available at Digi-Key:

R1: A105957CT-ND

C1: 493-3455-ND

------------ C2, R2:

1dB: 493-3460-ND, 15.0KXBK-ND

2dB: 495-4989-1-ND, 6.98KXBK-ND

3dB: 493-3466-ND, A105962CT-ND

4dB: 493-3467-ND, 3.48KXBK-ND

5dB: 493-3402-ND, 2.61KXBK-ND

6dB: P12102-ND, 2.00KXBK-ND

Just get 2 each R1 (C1 optional) and of the parts for whichever level of compensation you're shooting for.

My own build will be a switched variable circuit so I can dial in (or defeat) compensation at will. Here's the schematic, adapted from Pete's original:


Assembly is currently installed in a paperboard mock-up of a small cast aluminium box I plan to use ...


... while I sort out parts placement and labeling.





Haven't rushed to finish this as it's putting the cart before the horse. Still need to build cabinets for my Large Advent econowaves before I can experiment with BSC.

 

[Pete B]

Wow, Stuart, nice work, very nice!

 

[Denver jt]

Hi Pete

Any chance you can help me figure out what to buy to build my own BSC? I've never done anything like this before.

I have a pair of 25th anniversary Advents with the soft dome tweeter. I keep them about 10 - 12 inches from the wall. I use a Marantz 2230 receiver. I plan to put the BSC between the pre out and the main in.

So, based on your instructions, I believe it would be best to building a 2.2k. at 4dB with no C1.

I have no idea how to search for the capacitors or resistors of these values or where to buy them.

I would appreciate any advice. Thanks so much!

Hi EastWest-

I have almost the exact same setup. Was your BSC successful? Did you use the pre out/main in, or the tape loop on your 2230?

Thanks!

 

[nfafan]

Thanks Pete for re-cogitating this topic!

Some dumb questions if you don't mind;

This BSC is to built as one "BSC box" per left/right speaker, correct?
And if so, what allowances to make in the circuit to split the Tape Mon or Pre-Out/In over a stereo pair of BSC boxes? <- maybe this question would be best addressed with pictures of the BSC(s) attached to the system and speakers.

If you are trying to use a BSC pair with a typical AVR of today, would it be best to wait on the version you are working on that will use the "speaker outs" vs. trying to work in a single stereo pair in the Tape Mon loop - I ask as I (and probably many others) almost always switch out from 5.1 into 2.0 mode to listen to just the FR and FL speakers.

Thanks!

 

[EastWest]

Hi Denver,

Yes, it was very successful! I love these speakers now. It feels as though a blanket has been lifted off them.

I ended up using the pre out / main in. It works perfectly... but be aware that if use you headphones with your turntable, you will also be applying the EQ effects to them.

Luckily, my cousin is an engineer and built mine for me with an on / off switch. Though honestly, I do leave it on most of the time even when listening on headphones.

The on/off switch is also how I am able to A/B test the BSC and know for certain that it really does improve the sound of my speakers!

 

[Denver jt]

Thanks! I'm thinking of trying to build it myself....first attempt at doing anything like this.

I hope you don't mind a couple other questions....

Just so I fully undersand, you have one BSC unit/ circuit plugged into the MAIN IN (R and L), and then you have a switch to turn it on/off. Nothing in the PRE OUT.

Did you find a need for a change to the normal/increase/decrease switch on the back of the speakers?

So glad you are enjoying the sound. I really like my advents and love having an entirely "era specific" setup, but always looking to improve the sound with tweeks!!! It seems to be a never ending process, but so much fun along the way.

Thanks again,
John

Hi Denver,

Yes, it was very successful! I love these speakers now. It feels as though a blanket has been lifted off them.

I ended up using the pre out / main in. It works perfectly... but be aware that if use you headphones with your turntable, you will also be applying the EQ effects to them.

Luckily, my cousin is an engineer and built mine for me with an on / off switch. Though honestly, I do leave it on most of the time even when listening on headphones.

The on/off switch is also how I am able to A/B test the BSC and know for certain that it really does improve the sound of my speakers!

 

[Pete B]

Thanks Pete for re-cogitating this topic!

This BSC is to built as one "BSC box" per left/right speaker, correct?

Thanks!

I have edited the first post to answer your question, click on the link to a picture showing L and R
in one box.

 

[nfafan]

I have edited the first post to answer your question, click on the link to a picture showing L and R
in one box.

Thanks Pete for the reply - as I understand it now, this BSC box uses the pre-outs/main-ins to sit between the pre-amp and main-amp (much like an equalizer) and affects ALL connected speakers (A and B and not just the A pair).

That said, do you have a suggested solution for those who have receivers without the pre-out/main-in connections - I guess what folks have called the speaker-line-level?

Thanks!

 

[Pete B]

Thanks Pete for the reply - as I understand it now, this BSC box uses the pre-outs/main-ins to sit between the pre-amp and main-amp (much like an equalizer) and affects ALL connected speakers (A and B and not just the A pair).

That said, do you have a suggested solution for those who have receivers without the pre-out/main-in connections - I guess what folks have called the speaker-line-level?

Thanks!

Tape monitor loop.

Can't run A and B speakers together if one set does not need BSC.
I've been mainly a separates person, and don't run two pairs off the same amp.

 

[UtterAudio]

I am ordering parts for the 4.7 tape monitor version of the BSC box. In looking for the resistors, I am finding all the value specs I need (33k through 4.3k), but each is available in 1/2watt or 1watt versions. For this application, does it matter which? Is one preferable to the other? They are all exactly the same price. Thank you.

 

[Tim D]

I think Pete's going to say the resistor power dissipation doesn't matter. The tape monitor circuit is sub-milliwatt. I'm guessing that you could probably go as low as 1/8W resistors if that is the case.Let's wait for Pete to confirm though.

 

[UtterAudio]

Great. Thank you.

And, is there a preference between stranded and solid wire in the connections (beyond the practicality that the solid will be less flexible in the first instance but hold nice and firm once soldered)? Is tinned copper ok?

 

[UtterAudio]

And 16AWG for the hookup wire?

 

[Pete B]

1/2 Watt is fine, even 1/4.

16 ga is a bit heavy but fine, 18 might be better, stranded. I used Carol spools from Home Depot IIRC. This would be for inside the speaker.

Build the BSC with the leads of the components or similar gauge wire.