Capacitor bypass in crossover?

hanguy · « **on:** 2 Feb 2004, 04:16 pm »

Hi all,

I own a pair of Revel F30 speakers that I am thinking to upgrade some components in the crossover. The crossover is a design of ELYTONE, a crossover shop in Taiwan. All caps are custom trimmed, with values like 884uF, 386uF. What I am hoping to gain is more details and transparency in the mids and highs.

Does it make sense to add a small value high quality bypass capacitor, like auricap or TRT dynamicap, in parallel to each large cap? The large caps in the mid and woofer crossover look to be aluminum foil type while the two caps in the tweeter section is polypropylene (I am just guessing by the look of the caps).

Thanks in advance for any help.

Mike

hanguy · « **Reply #1 on:** 3 Feb 2004, 05:31 am »

Now that I did more research on the web, I found this web site http://www.northcreekmusic.com/Bypassing.html and learned that what people normally do is using cascade coupling.

My next question is: if I only change the caps in the tweeter crossover, leaving mid and woofer sections untouched, would I be creating some in-coherent effect, making the sound unbalanced?

Mike

Carlman · « **Reply #2 on:** 3 Feb 2004, 08:43 pm »

I'm curious as to what exactly you hope to hear by improving those crossovers. I know you said better detail in mids and highs. I had these speakers for a little over a year. The mids and highs were so sharply detailed that I can't imagine getting them to do that any better. If anything, I'd think you'd want a little sweeter highs to cut some harshness at the upper frequency range.

Another area I thought could've been improved was the progression of bass to midrange. It seemed to have a slight dropout of sound when frequencies moved from low to mids. Or, the mids were so forward that it just seemed this way...

So, if you were pulling back a little high and midrange I think the speaker as a whole would sound more neutral.. but, that's not its appeal. So, that's why I'm wondering why you're doing this and exactly what you hope to achieve.

...not that I'll be able to help because I don't know about xover design but, maybe to help others here who can...

Are you anywhere near the DC metro area? If so, Dennis Murphy could help you.

What's the associated equipment?

Thanks,
Carl

hanguy · « **Reply #3 on:** 4 Feb 2004, 02:19 am »

Hi Carl,

What I envision is to gain more transparency, hopefully make the image "float" a little more, may be effortless in the highs is another way to put it. When I looked at the crossover, there are two caps in the tweeter section. I just wonder if I upgrade them to auricap or TRT, would more information be presented to the tweeter and achieve what I envisioned? Would this upset the coherence of the speakers? Since I have two months off coming in March, I would like to experiment a little.

I am also aware of mid-bass dip problem that you mentioned but I am not bothered by that.

I have also added a bybee filter to each driver over a year ago and that helped to gain some effortlessness across all range.

FYI, I am using a Modwright+Empirical audio modified SONY DVP-S9000ES as transport, Proceed AVP2 as DAC and Proceed AMP5. Cables are VD Nite digital, Acoustic Zen interconnect and speaker cable.

Mike

WerTicus · « **Reply #4 on:** 10 Feb 2004, 02:06 pm »

get better speaker cables than acoutic zens.... that dosnt involve spending much money BTW... you could sell those and by some CAT5 cable and make better ones easily.

WerTicus · « **Reply #5 on:** 10 Feb 2004, 02:06 pm »

get better speaker cables than acoutic zens.... that dosnt involve spending much money BTW... you could sell those and by some CAT5 cable and make better ones easily.

aln · « **Reply #6 on:** 13 Feb 2004, 01:13 pm »

The first thing (in my opinion) one should do when seeking to improve a stero system is to upgrade the internal crossover. The amout of veiling caused by less than great crossover components is huge. I use Northcreek components throughout my external crossover (3 seperate crossovers per speaker all mounted on maple isolation blocks). I would recommend that you start by replacing the caps in the tweeter-midrange circuit. The most important thing is to have an EXACT match between each speaker in terms of total capacitence-this is what acounts for correct imaging from each speaker. Once the midrange-tweeter is correct than change the inductor for the crossover to the woofer-again another huge advance in sound. The best speaker cable in the world cannot compensate for a poor crossover.