Problems bi-amping 4430’s with 5235 Xover

[Tony]

Thank you Mvaldes and Jblbgw man, you were both spot-on with your diagnosis.

As to alternative crossovers to the 5235, I agree with Jblbgw man I have tried a Pioneer and DBX crossover with very disappointing results, before I managed to acquire 4430/4435 network cards. As I said before I like the result and do not find the 5235 has stamped an audio signature of any notable departure from when operating passive; just clearer presentation, with more definition and dynamics and with a slightly but definately wider and taller soundstage. As I have two 5235 crossovers I intend to experiment and intend to replicate Jblbgw man's upgrades in one, while keeping the other standard.

What alternative crossover would you suggest Mvaldes?

It would seem that the 5235 crossover has remained in active professional service for a great many years - its credentials cannot be too tarnished in this modern age.

[jblbgw_man]

Tony, just for the record I did not A/B listen test with the high grade audio caps, I just replaced them as a matter of course. Here is a link to the ones I purchased from RS Components http://australia.rs-online.com/web/s...duct&R=4534715 . The most significant difference was replacing the 5532's with the OPA627's. I did replace the TL074's with both Burr Brown 4134 and National Semiconductors LM4562 ........... to be honest there was no improvement in sonic performance with this upgrade. Now before everybody jumps in an quotes the spec difference of these chips, what I am saying is in this configuration/topology they did not exibit an improvement, thats not to say with a better decoupled power supply, circuit layout and better input shielding or gaurding around the input leads of the chip that they might exhibit better performance. Remember the idea of this mod to the 5235 was a quick and simple mod to impliment and not a re design. Good luck with the mods I found them to be a very worthwhile simple upgrade.

[mvaldes]

"What is a HI FI product" ?.... I have posted a simple upgrade of the 5235's in previous posts using Burr Brown chips and using high grade electrolytic caps in place of the originals. Look at my post here #8 http://www.audioheritage.org/vbullet...own#post223820 AND this one with pics http://www.audioheritage.org/vbullet...highlight=5235 This explains why you should try and retain the 5235 with the 4430/4435 cards. When looking at the graph of the voltage drives of the 4430/4435 cards you will notice the LF shelving applied ......... this is not insignificant, it is a 5dB reduction at 800Hz! If you can achieve that and the same phase response with something more bling bling then good luck! If the 4430/4435 cards produced standard 12, 18 or 24 dB filter slopes then no problems use anything that is "better" but I would be suprised if there was anything stock on the market that could duplicate the same slopes and phase response AND sounded "better" weather it be digital or analog. Don't forget the main problem with mixing consumer electronics with professional products is the huge nominal operating level difference of -10dBu for consumer and +4dBu for professional products, a whopping nominal 14dB difference! This in my view is why some people don't get the results from professional products that they think they are going to get.

Well, I’m sure that a 5235 with your tweak will sound much better than the stock ones.
But it will remain a entry level pro sound product and I wouldn’t use it in any Hi-End setup.
This is just my opinion (although there are other forumer that agree with )
The improvement you can obtain using a better sounding product are so important that you will not miss the lack of the LF shelving.

Michele

[jblbgw_man]

The improvement you can obtain using a better sounding product are so important that you will not miss the lack of the LF shelving.

Michele

[Tony]

Well, I’m sure that a 5235 with your tweak will sound much better than the stock ones.
But it will remain a entry level pro sound product and I wouldn’t use it in any Hi-End setup.
This is just my opinion (although there are other forumer that agree with )
The improvement you can obtain using a better sounding product are so important that you will not miss the lack of the LF shelving.

Michele

Michele, What crossovers would you suggest?

[mvaldes]

Michele, What crossovers would you suggest?

The only suggestion I can give you is based on my experience.
Bryston 10B or Pass XVR1. The XVR1 is the one that I've now on my system


Michele

[mvaldes]

Have you ever tried ?

Michele



PS: for the same reason I would never use again a 5235, I would never use again a DEQ2496.....

[JBL 4645]

So what am I chopped liver around here? Glad you sorted it out in the end trial and error it would seem.

[jblbgw_man]

Have you ever tried ?

Michele



PS: for the same reason I would never use again a 5235, I would never use again a DEQ2496.....

No ........ I have only tried BSS and DBX, I am very fond of the BSS and very not so fond of the DBX.

I can certainly notice the difference between a non 4430/4435 network and a standard 24dB LW filter network. I prefer the LF shelving in the 5235. I agree about the DEQ2496 I must of been temporarily insane when I bought mine, I certainly don't use it in my system, some claim here it makes a great RTA but I'm still not convinced of this either ...... more time needed experimenting...... would you like to buy one .

[mvaldes]

No ........ I have only tried BSS and DBX, I am very fond of the BSS and very not so fond of the DBX.

I can certainly notice the difference between a non 4430/4435 network and a standard 24dB LW filter network. I prefer the LF shelving in the 5235. I agree about the DEQ2496 I must of been temporarily insane when I bought mine, I certainly don't use it in my system, some claim here it makes a great RTA but I'm still not convinced of this either ...... more time needed experimenting...... would you like to buy one .

well....I'm ever been curious about this LF shelving.
The LF passive crossover is just standard 12db with a zobel network, no any other special circuit in it
So, I suppose that using a good electronic crossover should be fine.....and the XVR1 is a quite good one...
Do you have any other info regarding why the 4430 card for 5235 have this LF shelving ?

Michele

[Tony]

The only suggestion I can give you is based on my experience.
Bryston 10B or Pass XVR1. The XVR1 is the one that I've now on my system


Michele

And your using the XVR1 with 4430's?
you used the 10B previously with 4430's?

[jblbgw_man]

well....I'm ever been curious about this LF shelving.
The LF passive crossover is just standard 12db with a zobel network, no any other special circuit in it
So, I suppose that using a good electronic crossover should be fine.....and the XVR1 is a quite good one...
Do you have any other info regarding why the 4430 card for 5235 have this LF shelving ?

Michele

I don't know ... I did'nt design the 5235 and more specifically the filter cards for the 4430/4435, JBL could have quite easily made the filter cards standard 12dB slopes with standard 12dB phase response if they wanted or thought apropriate for the 4430/4435 ... but they did'nt ....... maybe you should take this up with the JBL design engineers and explain this to them and set them straight ......... maybe it was an oversight on their behalf!

[Chas]

Yup, ditch the switch, ASAP. I had the same problem here, although I do not run mine active, I did finally squirt some Caig deoxit in mine, when I upgraded the passive xover caps.

Check out Marchand for affordable, quality active xover solutions. Phil Marchand can likely do the CD eq for you, as well. Highly recommended.

http://www.marchandelec.com/

[mvaldes]

And your using the XVR1 with 4430's?
you used the 10B previously with 4430's?

Yes, I'm using the XVR1 with 4430
and yes, before the XVR1 I had the 10B, and used it with 4430


Michele

[mvaldes]

I don't know ... I did'nt design the 5235 and more specifically the filter cards for the 4430/4435, JBL could have quite easily made the filter cards standard 12dB slopes with standard 12dB phase response if they wanted or thought apropriate for the 4430/4435 ... but they did'nt ....... maybe you should take this up with the JBL design engineers and explain this to them and set them straight ......... maybe it was an oversight on their behalf!

OK.....I was just curios.
Anyway, I'm very satisfied of my setup with the PASS LABS crossover
I can't hear any problem, nor can my Clio measurement system....


Michele