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CLASS A
11-27-2007, 08:06 PM
Just really want to say a big thanks to Rich letting me pop round to his place to check out his 4345 etc...

Ive always been a JBL fan and owned the 250TI Jubilee's in the past but the 4345's are something else....OMG, the sheer size of these monsters just look awesome and photos from the web does not do any justice until you see them in front of you with your own eyes.

I took along with me a well modified Marantz CD12+DA12 which I thought would suite the JBL's greatly and some of my own music. My cd's consisted of some female vocals, R&B and some tracks with deep bass.

Oh, before I go into the sound quality, let me just say that Rich is such a chilled out guy and we had a great evening lasting past mid night.....

Ok, after the player wormed up abit, I sat down to listen to these beasts and 1st impression is that it is very musical especially with female vocals and the mid band is very smooth valve like ( can listen all day kind of feeling ) the upper end was very natural without any harshness ( I did increased the upper frequency level maybe extra +3db to what Rich had it to my liking). The bass is very tight and fast and came to a shock to me because I expected it to be looser and with more extension for a 18" woofer, I was very wrong.....what ever Rich did to the cross overs, he did a great job with the values.

One thing I did point out to Rich and this is only my personal opinion after listening to my music in his system is that I would love to hear the Bassline with more bottom end extension keeping the tightness that it has...that would be my perfect speakers....
Certain tracks of mine which I know well lost the kind of sweeping wave like kind of bass that hits you in the face and make you wanna say "WDF" if you know what I mean which In my current system will give you. Rich was interested in my views and adviced me that they are planning to fine tune the cross over.....Lets see what will happen and It will be very interesting....:D
Anyway, we planned to meet again tomorrow but this time it will be at my place for a blast at my system which I hope won't disapoint Rich.

Thanks again Rich for a great evening... its been educational...

BTW, my current system consist of the following:

SACD/CD Player: Esoteric X-01
Pre amp: Gryphon Sonata Allegro
Power amps: Gryphon Ref-1 mono blocks
Speakers: B&W N800
Subwoofer: Velodyne DD15 ( integrated into the system with RTA room frequency correction)

Thanks all and cheers.:applaud:

Robh3606
11-27-2007, 08:23 PM
What compression driver and horn were you listening too??

Rob:)

CLASS A
11-28-2007, 04:46 AM
What compression driver and horn were you listening too??

Rob:)

They're the Dusted-2435 and K2-H9800.

Cheers:D

Chas
11-28-2007, 05:40 AM
Class A, thanks for the story. Regarding your perception of the LF performance at Rich's, I tend to think the same here in my situation. I thought it was my room and perhaps also due to the fact that my 4345's are well away from my walls. I notice he has his "out there" as well.

A couple of SUB1500's really make a big difference with some of the music I listen to.:)

CLASS A
11-28-2007, 06:02 AM
Class A, thanks for the story. Regarding your perception of the LF performance at Rich's, I tend to think the same here in my situation. I thought it was my room and perhaps also due to the fact that my 4345's are well away from my walls. I notice he has his "out there" as well.

A couple of SUB1500's really make a big difference with some of the music I listen to.:)

Chas,

I'am sure also if the 4345's are nearer to a back wall, it will enhance the LF performance extension. I personally would also use some large floor spikes or some sort of isolation frame/platform that are solid enough to couple to the floor. This will ensure the LF will be solid /tight.

Chas, seems like you're a bass junkie too with your additional 1500's. If I own a pair of the 4345's, I would add a pair of velodyne DD15/DD18 to ensure I have a flat bass response down to 20hz and room frequency corrected without any dips or hills.
The Velodyne's DD series are very flexable and are not restricted to room placement coupled with its onboard 1000W class D amplifier its the best upgrade I've done in years. The difference with the sub is like night and day, not only the LF performance improved, also it has opened up the whole mid range.. I since cannot listen to music without the sub being on.

Cheers

leif
11-28-2007, 06:13 AM
Great picture and description.
How do you compare them with dodays state of the art speakers? I see you own a pair of B&W 800 also. How are they compare?

richluvsound
11-28-2007, 06:50 AM
Guy's,
thanks for the feed-back. ;) The LF issue is something GT talked about. Perhaps his suggestion of a 10 ft2 enclosure is the answer ! I did think about it at , but being my first project, I was reluctant to start free-styling.

Anyway, my turn. I'm off to class A's gaff for some aural-sex:applaud:

Rich

Chas
11-28-2007, 06:55 AM
Chas, seems like you're a bass junkie too with your additional 1500's. If I own a pair of the 4345's, I would add a pair of velodyne DD15/DD18 to ensure I have a flat bass response down to 20hz and room frequency corrected without any dips or hills.

Not much of a "bass junkie" these days! But, I do insist on hearing all there is to hear, if at all possible! I think we are on the same page, though.

My SUB1500's are independently EQ'd and run quite nicely down to 18-20 Hz. Near DIY earthquake stuff, if one is so inclined...:D

Also, individual subs provide with me room placement versatility allowing concentration on LF reinforcement in the sub 40 Hz zone- opposed to different issues for best 4345 set-up criteria.

CLASS A
11-28-2007, 08:04 AM
Great picture and description.
How do you compare them with dodays state of the art speakers? I see you own a pair of B&W 800 also. How are they compare?

My personal views comparing Rich's 4345 to my N800 is that the N800 are more detailed and dynamic...the pace is faster. I cannot comment on the standard 4345 but with Rich's, they are very articulate. best way to discribe the sound is much like panel speakers, the start stop on the midband is magical with no overhang.
The LF on Rich's have a very slight boom effect kind of sound whereas my N800 as we call it over here.." as tight as a duck's ass" Lol.:D
I'am sure with abit more careful placement and isolation to the floor, they can/will sound awesome.

Anyway, Rich just called and I'll be off to pick him up from the train station shortly. We will keep you posted with our findings.

Cheers all...:applaud:

JBLOG
11-28-2007, 10:56 AM
Thanks guys!

Interesting set of speakers to compare.

B&W with their hallmark 'British Sound' and the stereotypic 'California Sound' of JBL.

Ian Mackenzie
11-28-2007, 11:11 AM
What you were hearing is correct.

In full passive mode there is evidence of a small rise on the response @100 hz which is a function of the passive LF filter. Biamping is the prefered mode of operation.

Chas
11-28-2007, 11:22 AM
Biamping is the prefered mode of operation.

No doubt in my mind about this. Running full passive does not do justice to the 4345 and likely, all the bi-ampable 4300 series.

richluvsound
11-28-2007, 12:15 PM
well,

as my host preps some supper I sit and enjoy both a wonderful sound and hostpitality . Female vocals on truly brilliant kit can cause my eyes to leak:o: However, my 4345's are on par in every respect with the N800's . And , considering the there has to be about $80,000 between the recording and my ear ,I'm even more happy with mine and Guido's little Knock up's . I have made comments about certain qualities I'd like to improve and caused a few curt words and raised eyebrows. At first I was pissed off with it and now I just :) . The 4345's are not plug and play, they take tailoring . I have some real clever boy's in my corner helping . Ian, Guido, Merlin,saeman, 4313b ( when not on diaper duty) and many others here on the forum .The sound I'm after is in that big blue box . I have every faith in them. Someone said that you would have to spend a hell of alot to find a modern equivelant,they were'nt bullsitting.
B & W are a touch of class, so are the 45's except the 45's do nasty very well also. IMO the horn 10inch combo are what sets them apart from

mere mortals

rich

JBLOG
11-28-2007, 12:31 PM
The 'California Sound' will forever be known as ... doing nasty very well.;)

Guido
11-28-2007, 02:37 PM
They're the Dusted-2435 and K2-H9800.
Cheers:D

Thanks for sharing your impression.
You should know that Rich and myself didn't REALLY start to modify the 4345 crossover for that combo.
You heard a proto proto prototype.

Guido
11-28-2007, 03:08 PM
The LF issue is something GT talked about. Perhaps his suggestion of a 10 ft2 enclosure is the answer ! I did think about it at , but being my first project, I was reluctant to start free-styling.Anyway, my turn. I'm off to class A's gaff for some aural-sex:applaud:

Rich

It's the amps.
Member Class A use Gryphons.

As soon as you are in Berlin Rich we will hear your speakers with XA160's. No ore bass issues. Promise....

CLASS A
11-28-2007, 03:43 PM
Thanks for sharing your impression.
You should know that Rich and myself didn't REALLY start to modify the 4345 crossover for that combo.
You heard a proto proto prototype.

Guido,

I've heard your fab name mentioned so many times in these last two days. I'am aware of the proto proto prototype and I wish you guys all the success in the final version...no doubt it will be a stonker and I can't wait to hear them.
Rich and myself had a great evening banging out some tunes....I think I'am hooked with the JBL's again......JBL have SOUL....period....

Cheers.:D

CLASS A
11-28-2007, 03:52 PM
It's the amps.
Member Class A use Gryphons.

As soon as you are in Berlin Rich we will hear your speakers with XA160's. No ore bass issues. Promise....

Guido,

I do use the Gryphon Ref-1 mono blocks, 150W true Class A but with tons of current.
Personally, I never believe in bi-amping because you are still using the passive cross-over within the speaker....you can get great result using some massive current amps to overcome this but the ultimate way to go is fully active using 4 stereo amps or 8 mono blocks for a 4 way design.Cheers:)

4313B
11-28-2007, 04:04 PM
Personally, I never believe in bi-amping because you are still using the passive cross-over within the speaker....I believe in bi-amping and I build bi-amp only charge coupled 4344/4345 networks to that end. No passive components between the amp and the 2235H/2245H.

CLASS A
11-28-2007, 05:20 PM
Thanks guys!

Interesting set of speakers to compare.

B&W with their hallmark 'British Sound' and the stereotypic 'California Sound' of JBL.

The B&W N800 are far from what you might call "British sound"...they are still being used in Abbey Road studio and studios around the world for that matter.
Cheers...

CLASS A
11-28-2007, 08:45 PM
.

Not much of a "bass junkie" these days! But, I do insist on hearing all there is to hear, if at all possible! I think we are on the same page, though.

My SUB1500's are independently EQ'd and run quite nicely down to 18-20 Hz. Near DIY earthquake stuff, if one is so inclined...:D

Also, individual subs provide with me room placement versatility allowing concentration on LF reinforcement in the sub 40 Hz zone- opposed to different issues for best 4345 set-up criteria.

Chas,

My B&W N800 are not shy in the LF department by any means and when I purchased the Velodyne DD15 and from reading the frequency curve of the N800, I thought I have to set the cross-over point @ about 40hz on the sub. Little did I know until the main guy from Velodyne came down to set them up for me and after we did a initial RTA frequency sweep, I had some nasty dips and bumps.....He adviced me that on a particular set up like mine he would be very happy to set the cross-over point @ 70hz but we finally settled for 65Hz point...The sub gelled in nicely with the rest of the system giving support to the N800. My system now reaches down to 20Hz flatline without any boom boom effect.

Cheers

Andyoz
11-29-2007, 01:05 AM
Someone showed me this website a while back. Definitely one for B&W fans.

http://www.sterling-sound.com/

pos
11-29-2007, 02:33 AM
Were the 4345 biamped (and actively crossed over) during this listening session?

Isn't the H9800 a bit overkill for a 1.2khz crossover freqeuncy? Wouldn't a smaller biradial horn (ala 4348) by good enough for such a high cutoff frequency and steep slope?

CLASS A
11-29-2007, 03:12 AM
Were the 4345 biamped (and actively crossed over) during this listening session?

Isn't the H9800 a bit overkill for a 1.2khz crossover freqeuncy? Wouldn't a smaller biradial horn (ala 4348) by good enough for such a high cutoff frequency and steep slope?

The 4345 were running passive using a pair of mono blocks... SAC's ( German ) if I can remember correctly.

I think Rich would be the better person to answer you on the H9800 issue as I only trust my ears and to me they sounded great....

Cheers :)

Pls find attached pic of my set up.

timc
11-29-2007, 03:36 AM
Hi.

Very nice setup. Those amps i would take home any day :D


-Tim

richluvsound
11-29-2007, 03:40 AM
Were the 4345 biamped (and actively crossed over) during this listening session?

Isn't the H9800 a bit overkill for a 1.2khz crossover freqeuncy? Wouldn't a smaller biradial horn (ala 4348) by good enough for such a high cutoff frequency and steep slope?

Pos,

Guido and I wanted to compare Be dusted to Ti dusted. Be:applaud: Guess who won ? The H9800 is for another project. We will post a thread for that project sometime in the new year.

Rich

Ian Mackenzie
11-29-2007, 04:35 AM
Class A,

Nice setup.

One point to remember is your system is modern and relatively cost no object while your room acoustic is perhaps more typical of an audiophile situation. Rich's space is larger and very open.

In reference to electrical current from the amp yes it helps but the issue is the way the stock JBL crossover influences the woofer bass response in its pass band.

The first curve is a simulation usng JBL data with the stock 3145 network. divisions are 5 db.

Notice the hump around 100 hertz. This is quite audible.

The second curve you will note is far smoother in the bass and has a more optimum crossover to the midrange.

Some of you may think this curve is biamp mode. No.

It's the result of careful optimisation of the passive network using modern crossover software. Unfortunately the cost of such a network outweigh's the benefits and its simply easier to get a nice result biamping. The passive system also has a low impediance through the lower midrange and most contemporary amps sound best with a more typical 6-8 ohms.

Ian

richluvsound
11-29-2007, 05:06 AM
That is some system to be sure. But, the boy is still JBL on the inside.;)

If a pair K2's or the new Everest came to the door those Nautilus would on epay faster than you could say G.T.

Thanks for posting the charts Ian. As Guido pointed out the xovers still need some work and I'm trying to build a pro type system ,so at some point comparisons to strictly audiophile set ups become counter-productive.

Rich

CLASS A
11-29-2007, 05:06 AM
Ian,

Thanks for the clarification...Please excuse me for my ignorance with all things about JBL.

You are very correct about my space and Rich's and I suppose at the end of the day, maybe our goals in what we're trying to achive is different.

We plan with the help of a friend to load up my front end, pre and mono blocks to Rich's place and see what it sounds like as it should be very interesting.

Cheers

Chas
11-29-2007, 07:14 AM
Chas,

My B&W N800 are not shy in the LF department by any means and when I purchased the Velodyne DD15 and from reading the frequency curve of the N800, I thought I have to set the cross-over point @ about 40hz on the sub. Little did I know until the main guy from Velodyne came down to set them up for me and after we did a initial RTA frequency sweep, I had some nasty dips and bumps.....He adviced me that on a particular set up like mine he would be very happy to set the cross-over point @ 70hz but we finally settled for 65Hz point...The sub gelled in nicely with the rest of the system giving support to the N800. My system now reaches down to 20Hz flatline without any boom boom effect.

Cheers

Interesting, in my set-up I originally ran my crossover point at 50 Hz but after some experimentation, I found best LF articulation occured at a 40 Hz setting. The 2245H is still an awesome driver, IMHO. My EQ looks after a slight ~100 Hz room-boom effect, likely caused by proximity to the floor of the 18".

As Rich (and others, here) point out, these monsters are not plug and play...:)

JBL 4645
11-29-2007, 07:42 AM
Yes I’ve heard these beasts, at Rich's home, I can clearly remember using the SPL and measuring a smooth 100db within a few db A weighting and C clarity was astonishingly clear with a few watts I think he said (5 watts) this was back on Thursday July 26th 2007.:)

4313B
11-29-2007, 07:50 AM
Class A,

Nice setup.

One point to remember is your system is modern and relatively cost no object while your room acoustic is perhaps more typical of an audiophile situation. Rich's space is larger and very open.

In reference to electrical current from the amp yes it helps but the issue is the way the stock JBL crossover influences the woofer bass response in its pass band.

The first curve is a simulation usng JBL data with the stock 3145 network. divisions are 5 db.

Notice the hump around 100 hertz. This is quite audible.

The second curve you will note is far smoother in the bass and has a more optimum crossover to the midrange.

Some of you may think this curve is biamp mode. No.

It's the result of careful optimisation of the passive network using modern crossover software. Unfortunately the cost of such a network outweigh's the benefits and its simply easier to get a nice result biamping. The passive system also has a low impediance through the lower midrange and most contemporary amps sound best with a more typical 6-8 ohms.

IanYep. I'm glad you finally got that software working because it can really help with seeing what is going on. Actually even something like BB6P and XO3P can graphically show why these passive filters are a real pain (old pspice can too but it is probably beyond the typical hobbyist). One ends up with a ton of junk to optimize them and the expense, especially for lower crossover points is nutty compared to the benefits of bi-amping. I can't recommend enough going with bi-amp only.

boputnam
11-29-2007, 08:47 AM
...The LF on Rich's have a very slight boom effect kind of sound whereas my N800 as we call it over here.." as tight as a duck's ass"...This character will ease given time - those 2245H's are damned new. Mine took over a full-year to "break in", and improved all the while.


No doubt in my mind about this. Running full passive does not do justice to the 4345 and likely, all the bi-ampable 4300 series.Absolutely. I've run mine both ways - there is no point in comparing.


It's the amps.
Member Class A use Gryphons.

As soon as you are in Berlin Rich we will hear your speakers with XA160's. No ore bass issues. Promise....I agree - it is combination of full passive and using Class A amps, IMO. I am not sure going to PassLab's design will be the best result - it's damping factor is a relatively low 20.


...One ends up with a ton of junk to optimize them and the expense, especially for lower crossover points is nutty compared to the benefits of bi-amping. I can't recommend enough going with bi-amp only.Bingo.

IMO, the sub / woofer is best driven by Class AB, or even Class H amps with good damping factor / output impedance to control back EMF. That will give "tight as a duck's ass" response, if I understand what that means... :blink:

richluvsound
11-29-2007, 10:53 AM
The 'California Sound' will forever be known as ... doing nasty very well.;)

When Say "NASTY" I mean http://youtube.com/watch?v=G8dPso79Z9I&feature=related

;)

JBLOG
11-29-2007, 12:59 PM
When Say "NASTY" I mean http://youtube.com/watch?v=G8dPso79Z9I&feature=related

;)

Amen!

yggdrasil
11-29-2007, 03:16 PM
I have run the 2245's in my DIY's both with passive and active crossover.

The difference was so huge that going back to passive was not an option.

The passive crossovers are still used for the mid and high frequencies, but all components earlier used for the woofer have been removed.

When going to active crossover the bass definition and low extention was probably the largest difference.

I have probably tuned my boxes a bit lower than the 4345, so with my limited knowledge there is no need for a sub.

CLASS A
11-29-2007, 07:38 PM
I have run the 2245's in my DIY's both with passive and active crossover.

The difference was so huge that going back to passive was not an option.

The passive crossovers are still used for the mid and high frequencies, but all components earlier used for the woofer have been removed.

When going to active crossover the bass definition and low extention was probably the largest difference.

I have probably tuned my boxes a bit lower than the 4345, so with my limited knowledge there is no need for a sub.


Ok, if you're using passive to the mids and highs and active to the subs....wouldn't that be very simular to my setup with the active sub in play eq to the main speakers?????

BTW, would any of you JBL fans consider using something like the Velodyne DD series subs with the JBL's?... I think they both will work well together with their active onboard amp and room eq system. Just a thought...:D

Cheers

boputnam
11-29-2007, 08:56 PM
....wouldn't that be very simular to my setup with the active sub in play eq to the main speakers?????Uh, no. Isn't your HPF for the sub at like 40Hz? The 2245H has a lot to offer below there. That would be cutting off the 2245H at it's knees. However, with your cabinets, the sub may be constructive, but I cannot believe more tonal. :dont-know

CLASS A
11-29-2007, 09:24 PM
Uh, no. Isn't your HPF for the sub at like 40Hz? The 2245H has a lot to offer below there. That would be cutting off the 2245H at it's knees. However, with your cabinets, the sub may be constructive, but I cannot believe more tonal. :dont-know

My cross over point for the sub is at about 65hz, not that my main speakers cant go down any further..infact they are good down to about 35hz flat and down to 25hz +/- 3db. The whole purpose of setting them at 65hz is so that they can have more control over the room accustic ironing out/adding to certain areas of the frequency range within my system and room. This not only opens up the whole soundstage plus the DD15 are measured flat down to 20Hz without much if any distortion because the damping factor from the onboard amp is rated 1000w rms.

My personal view regarding the single DD15 sub is that they have more bottom end grunt/ control than the 2245H but I could be wrong.

I love to hear those 4345's in my room...that would be a great experience .....in my dreams....... Rich....sort me out..I promise I'll pump them VERY NASTlLY.:D

Cheers

Guido
11-30-2007, 01:09 AM
I do use the Gryphon Ref-1 mono blocks, 150W true Class A but with tons of current.

I did use many amps on my 4435. But the first impressions of the Aleph 2 was shocking great! Seems that the JBL's love that current capabilitys of huge class A amps.
Currently I have 2 Aleph XA160 (DIY) connected but can't give a real description of the sound as I simply didn't have enough time to really HEAR them. First impression is more 3D and open.....

Guido
11-30-2007, 01:11 AM
We plan with the help of a friend to load up my front end, pre and mono blocks to Rich's place and see what it sounds like as it should be very interesting.

GREAT IDEA!

Guido
11-30-2007, 01:14 AM
I believe in bi-amping and I build bi-amp only charge coupled 4344/4345 networks to that end. No passive components between the amp and the 2235H/2245H.

I'll setup a 4435 system with Aleph 2, Aleph 30 and a high end active crossover next week. It should be awesome and will make heaters unneccessary in the music room throughout this bloody winter ;)

richluvsound
11-30-2007, 02:59 AM
I'll setup a 4435 system with Aleph 2, Aleph 30 and a high end active crossover next week. It should be awesome and will make heaters unneccessary in the music room throughout this bloody winter ;)


And where did you get a high end active XO from YOUNG MAN ?

Guido
11-30-2007, 05:30 AM
And where did you get a high end active XO from YOUNG MAN ?

DIY :)

timc
11-30-2007, 05:30 AM
I have tried an Aleph 1.2 with my L65's. There was no controll of the woofer whatsoever. Midrange and Treble was awesome, but the bottom end was really bad.


-Tim

Guido
11-30-2007, 05:31 AM
I have tried an Aleph 1.2 with my L65's. There was no controll of the woofer whatsoever. Midrange and Treble was awesome, but the bottom end was really bad.


-Tim

Tim, something was wrong with your amp or whatever.
My Aleph 2 drives 2 parallel 2234 without any problem.

timc
11-30-2007, 05:37 AM
No, i dont think something was wrong with it. We tried it with several other speakers, and it worked fine. It was just big woofers it had problems with.


-Tim

Guido
11-30-2007, 05:53 AM
No, i dont think something was wrong with it. We tried it with several other speakers, and it worked fine. It was just big woofers it had problems with.
-Tim

2 fifteen inch 2234 are bigger and hell more difficult to drive than a L65 woofer toy.
Maybe I have no idea what a controlled bass is :o:

richluvsound
11-30-2007, 06:16 AM
Tim,

We have had this before.... If My SAC's can drive the 4345 VERY VERY WELL INDEED. I'd be inclined to check the phasing on your TOY woofs:D

Rich

timc
11-30-2007, 06:52 AM
What is SAC?

No polarity problem here :)

That said, it is not only the Aleph that didnt satisfy me on the L65. Tried ICE amplifiers with 600w. Sounded blurred. Meridian 557, even worse. Crown K2, not bad at all, but a tad warm sounding for my tast. Crown XTi-1000, now we're talking :D

The mid and highs of the XTi isnt noteworthy................

BTW: No pun intended. Just posting my experience with the gear.:)

-Tim

boputnam
11-30-2007, 07:54 AM
My cross over point for the sub is at about 65hz...Ah, I see that - I read the post wrong.


...the damping factor from the onboard amp is rated 1000w rms.I don't understand this, however. Damping factor is dimensionless. What is the damping factor?



We plan with the help of a friend to load up my front end, pre and mono blocks to Rich's place and see what it sounds like as it should be very interesting.Why not take your crossover, too, and run those 4345's the proper way. Except for the fact you'll never pry the crossover from Rich's fingers again, it should be risk-free... :)

richluvsound
11-30-2007, 08:33 AM
Hey Bo,

as we speak there is man Melboure slaving away with his new software and soldering iron to make my bi-amp fantacy come true:applaud:. I also have a K1 sitting at another members house awaiting the big day:applaud:. Not to mention the YOUKNOWWHATS on back order from YOUKNOWWHERE:applaud:

Rich

boputnam
11-30-2007, 08:44 AM
Coolio...

However, the best laid plans of mice and Aussies sometimes have longer time constants than envisioned. It should be trivial to stuff an active crossover into the signal path, and biamp just for a kick see. 'specially since you've got all those mono blocks headed your way.

IMO, Class A sucks for bass response, but whatever... :dont-know

CLASS A
12-01-2007, 04:08 AM
Why not take your crossover, too, and run those 4345's the proper way. Except for the fact you'll never pry the crossover from Rich's fingers again, it should be risk-free... :)


The coss-over is built into the sub with on screen display RTA style and room correction. Link
http://www.velodyne.com/support/digital_drive/DD%202.0_datasheets_final.pdf

Cheers

4313B
12-01-2007, 04:21 AM
Did Velodyne stop offering their Digital Drive SMS-1?

Anyone ever use it with JBL subwoofers like the 4645C or B380/B460?

Hofmannhp
12-01-2007, 06:44 AM
..I don't understand this, however. Damping factor is dimensionless. What is the damping factor?
..

the damping factor is:
the speaker impedance dived by the amp output impedance

HP

hjames
12-01-2007, 06:44 AM
Did Velodyne stop offering their Digital Drive SMS-1?

Anyone ever use it with JBL subwoofers like the 4645C or B380/B460?

Velodyne still has the SMS-1 listed on their site (http://www.velodyne.com/products/product.aspx?ID=15&sid=525v187g)

Opimax has a B-460 and an SMS-1 (and a related sub) in his system (see post 1)-
http://audioheritage.org/vbulletin/showthread.php?t=18407&page=2 (http://audioheritage.org/vbulletin/showthread.php?t=18407&page=2)

He has other parts in the system and can define the interactions better than I...

JBLOG
12-01-2007, 07:37 AM
Class A,

The passive system also has a low impediance through the lower midrange and most contemporary amps sound best with a more typical 6-8 ohms.

Ian

Ian,

In biamp mode, what does the impedance curve look like for the HF(2122,2425,2405) portion. Is it relatively smooth.... Any dips?

Ian Mackenzie
12-01-2007, 08:00 AM
It much nicer and only dips is 7 ohms.

Ian

Robh3606
12-01-2007, 09:48 AM
The Curve

Rob:)

boputnam
12-01-2007, 12:47 PM
the damping factor is:
the speaker impedance dived by the amp output impedanceYea, HP, I know - that was my point. Damping factor is dimensionless.

"CLASS A" had quoted '1000w RMS', which is obviously not the damping factor. I was asking for the value of "CLASS A" 's damping factor.

boputnam
12-01-2007, 12:49 PM
Why not take your crossover, too, and run those 4345's the proper way. Except for the fact you'll never pry the crossover from Rich's fingers again, it should be risk-free... :)Hey, Rich...

I'm coming through latest January, and can hand-carry an Ashly XR1001 - not the bestest, but would be worth a try. However, it is 120/60...

:hmm:

Ian Mackenzie
12-01-2007, 02:02 PM
The damping factor of the Aleph 2 is over 100.

It should be pointed out that that figure is obtained without massive NF.

It had no issues with the bass on the 4345, passive or biamped.

The Power supply was rated +1 12 amps , the transformer was 1000va.

Mr. Widget
12-01-2007, 02:30 PM
Did Velodyne stop offering their Digital Drive SMS-1?

Anyone ever use it with JBL subwoofers like the 4645C or B380/B460?
I've used it with the Sub1500s... best sound I have ever heard with that woofer. I expect it'd be killer with the big 18"er too, though it may not be ideal up to a ~300Hz crossover point.


Widget

4313B
12-01-2007, 03:23 PM
Hey Bo,

as we speak there is man Melboure slaving away with his new software and soldering iron to make my bi-amp fantacy come true:applaud:.I thought Guido built you a nice pair of cc networks for your 4345's...

I've used it with the Sub1500s... best sound I have ever heard with that woofer.I might have to pick one up if I decide to keep my W1500H's. Of course, it would probably work real well with 1500AL's in sub mode too.

Guido
12-01-2007, 03:41 PM
I thought Guido built you a nice pair of cc networks for your 4345's...

As long as I can't build or afford a nice discrete Passlabs style active crossover I will always stay passive.
All those PA active crossovers sound awfull!
I finished one Burr Brown opamp based active for 4435's and it sounds very very very good though:confused:

Maybe I need to change my opinion?

As said I'll setup an Aleph 2, Aleph 30 active driven 4435 soon. We'll see....

Guido
12-01-2007, 03:44 PM
The damping factor of the Aleph 2 is over 100.
It should be pointed out that that figure is obtained without massive NF.
It had no issues with the bass on the 4345, passive or biamped.
The Power supply was rated +1 12 amps , the transformer was 1000va.

THANK YOU FOR THIS STATEMENT. This bloody damping factor debate kills me.

boputnam
12-01-2007, 03:50 PM
The damping factor of the Aleph 2 is over 100.That's pretty good.


This bloody damping factor debate kills me.Ah, buy Guido - it does matter. Back EMF is what led JBL to their "Differential Drive" technology...:)

Ian Mackenzie
12-01-2007, 03:52 PM
I thought Guido built you a nice pair of cc networks for your 4345's...
I might have to pick one up if I decide to keep my W1500H's. Of course, it would probably work real well with 1500AL's in sub mode too..

He did, at least I taut so!

Guido
12-01-2007, 04:03 PM
Ah, buy Guido - it does matter. Back EMF is what led JBL to their "Differential Drive" technology...:)

Sure, but 100 and even 50 (like the aleph 30) is more than you'll ever need.

richluvsound
12-01-2007, 08:13 PM
Guys,

I moved them back to wall a metre . They are now a metre from the wall

The LF has gotten louder, but not tighter. I want the snap and the rumble from that bloody big Woof;) There has been so much talk about Bi-amping that I feel compeled to try it out for myself. I have not bi-amped
the 45's yet, but I did have the 4435's bi-amped and liked the result. I'm not trashing my Charge Coupled networks . Guido did a brilliant Job- they designed them with bi-amping in mind. I have nothing to lose and only my own experience to gain.

Rich

Robh3606
12-01-2007, 08:25 PM
There has been so much talk about Bi-amping that I feel compeled to try it out for myself.

You really should give it a whirl. It made a difference on the XPL-200A's and the bass on my 4344's is punchy and well controlled. I am building up a pair of L250ti Jubilles and they will have a biamp option.

Rob:)

Ian Mackenzie
12-02-2007, 12:48 AM
You really should give it a whirl. It made a difference on the XPL-200A's and the bass on my 4344's is punchy and well controlled. I am building up a pair of L250ti Jubilles and they will have a biamp option.

Rob:)

Yeah like a Wirlpool washer..and blow lots of bubbles....:D.

Lord Sommerville,

I have been otherwise busy but knowing you are a perfectionist there has been some interesting progress.

We all know by now that biamp has virtues in terms of controlling and providing the woofer with a smooth low end response.

Today I set up a basic model to study the options of biamping the JBL 4345.

For a while now some members have had moanings about the woofer not integrating and tracking propertly with the mid cone in biamp mode and full passive mode

I always felt that the biamping was not perfect and it tended to be either too much or too little. The picture tells the story below.

It would seem all is not that simple as looking at voltage drives in determining a smooth transition.

The first curve is the voltage drive biamping using a 290hertz 18 db slope butterworth filter.

With the model taking into account the location of the drivers on the baffle in the X,Y,Z dimensions there is a depression of about 2 db @300hz starting at 150 hz up to about 400 hz.

These latter curves are taken with a 290 hertz 3rd order butterworth active filter. The mid cone and the horn and slot are all out of phase with the woofer(per 3145 schematic).

The second curve is the model with the mic set on axis and positioned mid way between the woofer centre and the mid cone in the vertical plane.

The third curve is the model with the mic set on axis and positioned centrally between the horn and the mid cone.

The mic is at a distance of 3 metres from the baffle. So this second curve is a realistic simulation of the listener seated and their ear on axis with the centre point of the horn and mid cone.

Notice how the depression becomes more pronounced as with the mic raised to the position where the listeners ears are located.

The depression is caused by what is called a lobe around the crossover transition. Lobes area directional a sound fields as a function of frequency in terms of the vertical polar response. The slope and phase relationships of the crossover filters and the relative locations of the drivers determine the frequency spread and angle of the lobes with respect to the baffle. With the woofer having a deeper profile than the mid cone the issue is made worse.

The fouth curve is with a LR 24 db filter with all drivers in phase at a crossover point of 290 hertz. The mic position is the same a the second curve.

The 2rd curve is much smoother. This can be accounted for due to the rapid stop band action of the filters and the phase relationships of the LR tranfer function. The lobe action of the LR filter is much more forgiving.

Notice also the comb filtering in the transition of the horn and the slot radiator. This is proof of the realism of the model.

The point is however if you are a 4345 user and are using the stock 18 db filters you will need to apply some Eq in the crossover region. This is aside from room and other environmental issues.


I have not investigated other filters at this stage.

Ian

Ian Mackenzie
12-02-2007, 01:06 AM
Here is another popular filter.

The LR 12 db filter here used for biamping.

The same conditons apply as per the above post.

The mid cone, horn and slot are electrically out of phase with the woofer.

The vertical polar pattern is almost as good as the LR24 db slope filter and varies little from central to the woofer and mid cone and central to the mod cone and the horn.

The second curve is the stock full passive network modelled under the same conditon. The vertical polar pattern dips about -1 db @300 hertz and is consistent in both mic locations discussed earlier.

Unfortunately the hump created by the LF filter swamps the bass midrange transition.

So what does all this mean. Well in full passive mode we have both good and bad. A reasonably even vertical polar response around the woofer midrange transition but a noticable hump in the upper bass response and less than ideal damping of the woofer at Fb.

In the stock biamp mode the above issues almost trade places. The bass response is improved dramatically but the vertical polar response around the woofer midrange transition is far from ideal.

In a carefully set up system the above issues are quite audible.

Of course even modelling does not give a perfect representation of that happens in your own room but it does help identify the poblem issues and how to deal with them. This would otherwise be a hit and miss affair by ear and at worst a zealous over use of active equalisation.

Unfortunately there are very few active filters that will allow you to trial different slopes and frequencies on the fly other than the digital loudspeaker management systems like DECX, DBX Drive rack and the UltradrivePro 24/96.

The analogue filters I am preparing will allow trialling any of the above active filter transfer funtions in situ and offer fine adjustment in pure class A operation.


Ian

richluvsound
12-02-2007, 05:05 AM
[QUOTE=boputnam;193086]Hey, Rich...

I'm coming through latest January .

Bo,

your welcome with or without the Ashley !

Rich

richluvsound
12-02-2007, 05:11 AM
Ian ,

I think I understand. :(

Rich

Robh3606
12-02-2007, 05:23 AM
Hello Ian

Nice Sims!! Just goes to show you why single point in space measurements have such limited value.


but knowing you are a perfectionist

Sure you got right guy?? This hobby would drive a perfectionist absolutely bonkers:banghead:

I find it interesting. If I remember correctly at one time Greg was recomending using 12db active slopes in the transition. I think that's what Bo uses. I was using 24Db with the M553 and went to 12db with the DX-1.


The analogue filters I am preparing will allow trialling any of the above active filter transfer funtions in situ and offer fine adjustment in pure class A operation.

Are you going back to your original active filter project or upgrading it??

Rob:)

4313B
12-02-2007, 07:13 AM
I am building up a pair of L250ti Jubilles and they will have a biamp option.You will probably need to fiddle with the filter on the 108H if you are going to make the system bi-amp capable. Model the filter and see what happens when you remove the high pass components from the band pass filter...

This hobby would drive a perfectionist absolutely bonkers:banghead:It can be quite irritating. One has to left alot of stuff go. :rotfl:

Unfortunately there are very few active filters that will allow you to trial different slopes and frequencies on the fly other than the digital loudspeaker management systems like DECX, DBX Drive rack and the UltradrivePro 24/96.Every boy and girl should have a DECX to play with.

With SoundEasy one should be able to dial in anything they want for their 4345's. A person could make a lifestyle out of playing around with all the various combinations. It can be pretty fun. I'm kind of surprised that Zilch hasn't sprung for a copy of SoundEasy.

Earl K
12-02-2007, 07:49 AM
Nice voltage drives Ian !

- What generates those "twin peaks" in the upper-end response of the 2122H ?
- ( ie ; Are we looking at pure voltage drives ( with resonances maybe ) or have you blended into these system traces, some actual acoustic responses from certain drivers ? )

http://audioheritage.csdco.com/vbulletin/attachment.php?attachmentid=29761&stc=1&d=1196583765

:)

opimax
12-02-2007, 07:56 AM
I do have a SMS1, B460 driven by a Adcom g555 bridged and a Velodyne SPL1200r. I run the SMS on both subs. I find the the Velodyne goes lower and more impact. More Xmas, newer class D amp at 1000w w/2000 peaks compared to older 600w on B460. I would admit my stuff might do better with a more knowledgeable person/measuring techniques to get more out of it. The 460 isn't designed to go as low as the Velo I was told, no material down that low to produce until home theater pretty much.

Also the Volo is corner loaded and the b460 is almost in the middle of the room. I am hoping a friend buys my 1200r and I will go to a DD15. I will anyway but it would happen sooner :) DD is 1250W w/peaks to 3000


Mark

CLASS A
12-02-2007, 08:52 AM
I do have a SMS1, B460 driven by a Adcom g555 bridged and a Velodyne SPL1200r. I run the SMS on both subs. I find the the Velodyne goes lower and more impact. More Xmas, newer class D amp at 1000w w/2000 peaks compared to older 600w on B460. I would admit my stuff might do better with a more knowledgeable person/measuring techniques to get more out of it. The 460 isn't designed to go as low as the Velo I was told, no material down that low to produce until home theater pretty much.

Also the Volo is corner loaded and the b460 is almost in the middle of the room. I am hoping a friend buys my 1200r and I will go to a DD15. I will anyway but it would happen sooner :) DD is 1250W w/peaks to 3000


Mark

Optimax.

The DD15 is a bad ass sub in any means....infact, people in the know much prefer the 15 to the 18.
Cheers

Mr. Widget
12-02-2007, 09:45 AM
I am hoping a friend buys my 1200r and I will go to a DD15.The SPL series have more boom and many prefer them for movie soundtracks... the DD series is far tighter and better suited to music playback... of course it'll shake the hell out of you when the monsters walk by too, but in a tighter and more controlled way.:D

In my opinion the 2245 based subs and systems from JBL really shine in their "musicality". They can't begin to compete with today's top drawer dedicated subs in dredging the depths of infrasonic reproduction, but they do low bass in the reproduction of music like few other devices.


Widget

Mr. Widget
12-02-2007, 10:00 AM
Nice Sims!! Just goes to show you why single point in space measurements have such limited value. Yes, those sims are pretty cool... it would be interesting to see how they compare to real world measurements... I'd expect that they would be close enough for all practical purposes... I remember shortly after getting CLIO and taking a simple 1m FR curve of an L100... because of the crazy driver layout, the response was radically different if taken on the tweeter axis or flipping the box and using the woofer as the "measuring point" ŗ la the 4311. It wasn't a simple matter of off axis tweeter roll off but a radical shift due to time and phase issues.

As Ian has suggested, using something like the DSP controlled DEQX does afford one the option of actually trying out many of these directions and getting to hear what these graphs are showing us... I find it most interesting that often areas of a plot that jump out at you don't affect the sound as much as things that barely show up at all and sometimes don't even show up in a FR plot. Then there are those times when a bump around 250hz does make the sound thick and congested.:D


Widget

4313B
12-02-2007, 10:40 AM
Yep, as we've said before, one has to take a ton of measurements to find out what is real and what isn't.

I have not investigated other filters at this stage.They're cake to crank out with your software. The nice thing is you can try them all out on the fly and see which you would prefer to build permanently. Don't blow stuff up though like a couple other forum members almost did. I designed completely new networks for both the 4345 and 4355 just for fun that sounded real nice, they just didn't sound like 4345's and 4355's anymore. :rotfl: Also, the digital filter sims sound different than the actual passive filters so that's another potential consideration.

As Ian has suggested, using something like the DSP controlled DEQX does afford one the option of actually trying out many of these directions and getting to hear what these graphs are showing us... SoundEasy actually has a crude version of that if one has the correct soundcard in their PC.

Ian Mackenzie
12-02-2007, 12:32 PM
Thanks for all the responses.

The only reason I got around to this was because I had a cold and could not be bothered doing anything else. Trust me its not a lifestyle or splurge or something I propose to do around here on a regular basis..its too time consuming. I am not a simulation spin Doctor..............:D

There was real intent behind the exercise as a what gives with these old 43XX systems that can either sound miserable or great depending what you do and how you do it..... Common sense and logic prevail and its not difficult to sort out otherwise mind bending issues with these sim models.


I was only interested on the bass mid range transition. We know about the boundary issues and the filter issues with the 2245H and that requires a different work around. There are other of issues elsewhere but they require a complete rethink of the entire design.

Getting a smooth power response in the vertical axis is always going to be a problem with 3 or 4 ways systems because of the physical spread of the drivers.

The magitude of the drepression was quite surprising ...either a hump or a dip in the lower midrange is going to effect the midrange and upper bass tonality. I find it quite interesting how hearing perceptions align with these models.....the cause and the symptom.

Rather than do a custom filter which would be difficult for people to emulate I decided to look at the more common filters first.

4313-B , I am not sure I understand what you are saying. When I first heard the stock 3145 passive filters (as a base line) I thought I was just okay in terms of transparency and there was a lot of potential (passive and biamped with the DX1) but remember we are dealing with a 20+ year old system so it is what it is.

Getting these things set up right is 98% of what you hear and sorting out the active crossover is part of that. Some people will prefer a butterworth filter while others will prefer the LR filters while some will just dial up their graphic equaliser. Its a subjective thing but usually one filter will have the lesser of all evils.

One of the issues with all this stuff is you can try too hard and end up with a really analytical and sterile sound and a very very short play list. That is not the intent of home entertainment. ie The 6332 is not meant for home use.

Its a lot easier to focus on the things that people find annoying and what they like appealing. ie dislike soggy mid range and like tight bass or as the case maybe. I am just looking at the ironing out major bumps in the road, not re engineering a whole new suspension.

The more a system appeals the more they are likely to listen to it.:)

I do have some polar plots but they are not as much fun to look at!

Ian

opimax
12-02-2007, 12:56 PM
I am music 1st, DD15 is in my future, just when. the b460/adcom has not done much for me, really wishing I was saying the opposite. I need to try it w a different front end, maybe stereo only or at least not this Sony 9000

Sorry, back on topic

Mark

4313B
12-02-2007, 03:58 PM
4313B , I am not sure I understand what you are saying.I'm saying that the tools we have today are pretty fun to play with. The DECX, SoundEasy, LEAP, MLSSA, WT3, etc.; They have alot to offer and can be quite illuminating. They are nice tools to have around.
When I first heard the stock 3145 passive filters (as a base line) I thought it was just okay in terms of transparency...I think you just described every system from that era. I think that's why so many people post how much better their loudspeakers sound with even a simple L-Pad or capacitor change out. The stuff just gets old and tired.
Getting these things set up right is 98% of what you hear...Yeah and something tells me these things weren't meant to sit on a living room floor. They can be tough to place successfully in a living room.
One of the issues with all this stuff is you can try too hard and end up with a really analytical and sterile sound and a very very short play list.I think that is right on the money. It gets to the point where the typical source media sounds exactly like what it is - mass produced "stuff".

Ian Mackenzie
12-02-2007, 04:08 PM
I think we need to come up with some hard wired L pads and have the old ones in there just for show.


So how do you go with the 4344 and the 4345's at home?

Rick's basement sound lounge was like a JBL HiFi shop in the 70's...43XX wall to wall... Clark and I felt like we had walked into the JBL temple..it was great!

I think Rick is aching for some of the newer networks to try out.

Ian

boputnam
12-02-2007, 04:28 PM
Yep, as we've said before, one has to take a ton of measurements to find out what is real and what isn't.Yea. Models in BBP or whatever are real intriguing and even compelling, but actual measurement of the result is reality. Without that, you can sit in your easy chair psycho-acoustically convincinced youv'e built the best possible, but reality may be quite a different thing, entirely.


I think we need to come up with some hard wired L pads and have the old ones in there just for show.Yea, there was limited discussion on that, some time back. Makes perfect sense.

4313B
12-02-2007, 06:19 PM
Yea, there was limited discussion on that, some time back. Makes perfect sense.Yeah for you and me that might be just fine because we can swap out resistors as desired but most people will have none of it. As example, one forum member had his 4355's set perfect for his taste and then moved them to another forum member's house. That forum member immediately cranked up the L-Pads and proclaimed the result perfect.

The fixed resistor version of the 4345 merely has the L-Pads set to zero and then the appropriate resistors substituted in. Once you have that baseline you can use the modeling software to try different fixed pads to maintain the correct voltage drive curve while increasing or reducing the voltage level. I used the zero L-Pad positions for both the 4345 and 4355 as baseline (-2 dB across the board for the 4344). I built the prototype and was pleased to find that they didn't need any further adjustment but someone else might disagree and want something hotter or colder.

Bottom line though is exactly like G.T. said, L-Pads really suck (as do tapped autotransformers). :barf:
But, like compact discs, they are convenient. :p

Ian Mackenzie
12-02-2007, 09:04 PM
I think it should be organised and we set up a table of values.

This will I hope in the end mean more consistent performance from users and of course more reliability..we know how bad those L pads can be!

Ian

Valentin
12-03-2007, 09:16 AM
One of the issues with all this stuff is you can try too hard and end up with a really analytical and sterile sound and a very very short play list. That is not the intent of home entertainment. ie The 6332 is not meant for home use.

most of the speakers that JBL has been famous for where not built for the Home Use

But i do understand where your comments on the 6332 i have them in a home environment with pair subs and yes its an analytical set up the other day i compared them with Thiels 3.6 speakers

the thiels had more air or ambiance but were Les defined
Jbl where more dynamic and each instrument was precise in tone and image but had less information of the space

that sterile sound (not so much ambiance) is probably the use of a very controlled directivity and also damped tweeter which is probably the intended use for the studio environment

i have compared the lsr curves of the consumer hi ends with the LSR and increased directivity of the high freq seems to be one of the factors

JBLOG
12-03-2007, 07:58 PM
the damping factor is:
the speaker impedance dived by the amp output impedance

HP

Be carefull with specs on Damping Factor. Damping Factor of a particular amp will often very with frequency. For example, here is a graph of the damping factor as a function of frequency for a Belles 350 amp. It has a damping factor of 2000 until 500Hz.

http://www.soundstagenetwork.com/measurements/amplifiers/belles_350a_reference/chart4.gif

boputnam
12-03-2007, 09:42 PM
Be carefull with specs on Damping Factor. Damping Factor ... will often very with frequency. ... Excellent point. Which is why high damping factor is very relevant in LF / subwoofer applications. In other portions of the FR, damping factor is less significant because the back EMF is less (the transducers have diaphragms of significantly less mass) so the amp - even Class A - can handle it with less compromise to performance.

timc
12-04-2007, 01:16 AM
Can someone please explain why an amplifier with lesser damping factor can have a much better controll of a sub, than an amplifier with twice the damping factor?

Slew rate also seems to be about the same.......

The comparison was between a ICE based amplifier with 1000 DF, and a Crown XTi-1000 with "only" 500 DF

DF was constant in the used freq. range.


-Tim

Ian Mackenzie
12-04-2007, 03:43 AM
This is becoming way off topic for the thread .

Its always been a fairly subjective thing and I would take DF figures with a grain of salt anyway.

In a conventional A/B and or class B amp the design is based largely of negative feeback to create output impediance =DF.

Its a measure of the voltage drop from open circuit to the rated load and this is a sine wave. The problem is music and particularly bass transient is not a constant sine wave. The power supply is normally not regulated and has big influence along with the stability of the amplifier.There are a lot of other factors like the design of the output stage.

Just trust your ears

JBL 4645
12-04-2007, 07:38 PM
Ian

Do you have any pictures, of where you placing the microphone, when calibrating the differences with the variety of crossover filterís?

Ian Mackenzie
12-04-2007, 09:28 PM
4645,

I used a rather large invisible wand!

I am too modest to display it here....

if you go here you will see this was a simulated model.

http://www.audioheritage.org/vbulletin/showpost.php?p=193142&postcount=73

These models are used to simulated and predict certain aspects of the design, the more accurate the imput data the more reliable the model. Often actual measurements are not practical and these models help in determining system performance.

JBL 4645
12-06-2007, 08:11 AM
Ian

I looked at the page a few nights back. So what is X Y Z? Does that have something to do with microphone positions?

Thanks.:)

Ian Mackenzie
12-06-2007, 10:32 AM
Yes, up or down, left or right, in and out.

Ian

readswift
01-01-2008, 08:15 PM
I finished one Burr Brown opamp based active for 4435's and it sounds very very very good though:confused:



Decent 5532 done right (Signetics) should sound just as good afaik, at least someone with plasma tweeters was proud of those :)