My "New" 4345 Clones

[BMWCCA]

This looked like as good a place as any to ask this question:

My "new" 4345s have the custom CC networks. I have an Ashly XR-1001 on the way. The photo shows it to be the new "graphite" version with rear-mounted power switch and therefore I presume the auto-balanced XLR jacks.

What I'm hoping to use are two Crown amps: PS-400, and PS-200. I also have two Crown PS-MOD/X adapters to allow XLR input to the amps. I'm a bit of an electronics idiot and don't understand the difference between the PS-MOD/X and the PS-MOD/A. The manual says both allow balanced input but the X is passive using a transformer while the A uses "active circuitry". Which is preferred? What are the advantages of either over the other? I have been offered a pair of PS-MOD/A's as well, I just can't tell if I need them.

In general, is there an advantage to using balanced inputs if my runs between the Ashly and the Crowns is only a couple of feet? I won't have balanced output from the pre-amp anyway so I'll be either using the 1/4 TRS Ashly inputs or an adapter to the XLR. What is required to connect to the Ashly properly from a pre-amp with RCA jacks?

This is most likely the first of many questions I'll have, but it's critical to me just to get started on the right foot. Thanks in advance for your replies.

[Mike Caldwell]

The passive transformer version will give complete isolation between your pre amp and the amp. That would help get rid of any ground hum problems you have....if any in the first place. The transformer depending on the quality could be a weak link in the signal path, it could start to saturate with high level low frequency input signal, it could limit the frequency response at the extremes. Could is the key word. The active version would not give you isolation but you may not need it. Frequency response may be wider.

I would try it without any of the input plug in modules and use either the 1/4 jacks or the terminal strip. On the outputs of the crossover try it first using pin 1 to the ring of a 1/4 inch plug or to the ground terminal on the amp and pin 2 to the tip of the 1/4 inch plug or to the + terminal on the input strip. The other way is to tie pin 3 and pin 1 on the XLR together inside the XLR plug that is plugged into the crossover.

The PS200 and PS400 are basically Crown DC300 and D150 power amps. I used many of them with active crossovers using the pin 1 and 3 tied together method.

Let us know how it works.
Mike Caldwell
www.mikecaldwellaudioproductions.com

[Fred Sanford]

This looked like as good a place as any to ask this question:

My "new" 4345s have the custom CC networks. I have an Ashly XR-1001 on the way. The photo shows it to be the new "graphite" version with rear-mounted power switch and therefore I presume the auto-balanced XLR jacks.

What I'm hoping to use are two Crown amps: PS-400, and PS-200. I also have two Crown PS-MOD/X adapters to allow XLR input to the amps. I'm a bit of an electronics idiot and don't understand the difference between the PS-MOD/X and the PS-MOD/A. The manual says both allow balanced input but the X is passive using a transformer while the A uses "active circuitry". Which is preferred? What are the advantages of either over the other? I have been offered a pair of PS-MOD/A's as well, I just can't tell if I need them.

In general, is there an advantage to using balanced inputs if my runs between the Ashly and the Crowns is only a couple of feet? I won't have balanced output from the pre-amp anyway so I'll be either using the 1/4 TRS Ashly inputs or an adapter to the XLR. What is required to connect to the Ashly properly from a pre-amp with RCA jacks?

This is most likely the first of many questions I'll have, but it's critical to me just to get started on the right foot. Thanks in advance for your replies.

Check the Ashly manual to see what it says re: going two-conductor/unbalanced into a TRS jack, some don't recommend using a TS plug but instead wiring up a TRS with only two connections. Feel free to link to a manual or e-mail one to me if you want.

I also have tons of RCA/XLR/TRS/etc. adaptors, let me know if you'd like me to bring over an assortment for you or make any specific cables to test things out. I need to make a C'Ville trip in the near future, anyway.

My guess is that an active MOD/As may have cleaner/wider-freq specs than the passive, but that seems like an easy thing to swap later. Possibly also something you wouldn't care as much about unless the feed lines to the amps were long distances.

je

[boputnam]

...I suppose it really isn't going to make any difference unless I pick up a hum somewhere along the way.

Mike and Fred got it nailed. I agree with Fred - I'll bet those old Crowns are not going to "like" a TRS plug - the Ring may not be in the right position to hit that second contact. I've run into this before. You should try the TS version, first. That may work fine. Or, go with that winkie 11-pin connector...

btw... Enjoy those bigboys. Do let us know.

[BMWCCA]

btw... Enjoy those bigboys. Do let us know.

I'm sure you'll be hearing from me! Thanks.

After all the reading I've done on LH, I'd have to say your contributions were instrumental in my decision to pop for them.

My wife just refers to everyone here as a co-instigator.

[boputnam]

After all the reading I've done on LH, I'd have to say your contributions were instrumental in my decision to pop for them.

Aw, shucks, Dorothy!

I should retire - my work is done! However, your work is just beginning. The 4345 is not user friendly. It's performance benefits from careful set-up and knowledgeable system tuning. These are not trivail tasks, and your ability to execute them will improve with every iteration you try. Do keep trying and keep challenging yourself. And that, one day, will almsot certainly lead you to some TAD TD-2002's. You will never reach the limit, me knows...

My wife just refers to everyone here as a co-instigator.

Yeah, pretty much...

[John]

My wife just refers to everyone here as a co-instigator.

Well I agree we are guilty as charged !!!

[BMWCCA]

However, your work is just beginning. The 4345 is not user friendly. It's performance benefits from careful set-up and knowledgeable system tuning. These are not trivail tasks, and your ability to execute them will improve with every iteration you try. Do keep trying and keep challenging yourself.

Yeah, that had entered my mind, since I'm the third owner in just over two years! But my mom always said I was a problem child, too.

Don't worry, I'm not selling the L7s. Looks like I'll need something to actually listen to while I tinker.

So why would these be any more problematic than, say, a 4343? Or are you 4345 guys just never happy? Go ahead; it's too late to turn back now!

[Fred Sanford]

Good points on the Crown side re: 1/4" TRS jacks, but I was referring to the Ashly side, since he mentioned having the Crown's XLR modules - I remembered some Ashly models advising against using a mono jack in either the balanced ins or outs, not wanting to short the R&S contacts (caused distortion?). It's a vague memory, but I thought it was worth checking the manual.

je

[BMWCCA]

Both the DC300 and the PS400 only had a two conductor 1/4 inch jack. You do want to use just a TR plug on the amp input and do what is needed with pin 3 at the sources output.

I remembered some Ashly models advising against using a mono jack in either the balanced ins or outs, not wanting to short the R&S contacts (caused distortion?). It's a vague memory, but I thought it was worth checking the manual.

Thanks, everyone, for the backup. According to the Ashly manual, it looks like they addressed the problem, at least in the two recent XR-1001 and XR1001 (yeah, it appears their updated model uses a hyphen in the model number on the unit though their text is not consistent). I'm going to start with TS standard mono 1/4" (I assume that's what Mike meant) and see how it goes.

One more (today) ignorant question? What's better for the cross-over to amplifier run; shielded co-ax or twisted-pair? I'm guessing the former.

Thanks.

[Mr. Widget]

Don't worry, I'm not selling the L7s. Looks like I'll need something to actually listen to while I tinker.

I am assuming you don't have advanced measurement equipment or extensive experience with multi-amped systems. If that's the case here is a trick that might be useful. (Actually it might be useful anyway.)

Set up your L7s next to your new babies and parallel the CD player to them and the new system. If you are short on gear, you can use an old receiver or almost anything to power the L7s as they don't have to be "perfect." Run the L7s "dry" or adjust the amp to sound the way you typically like and listen to them. Now balance the output level to match the new speakers and switch back and forth getting the big beasties to sound as similar to your "standard" as possible. I think I'd run them single amped first to set up the L-pads, then throw the Ashly into the mix.

You need to get the two systems to sound as similar as possible on the widest range of music... after that you can use micro adjustments to flavor to taste.

So why would these be any more problematic than, say, a 4343?

I don't think they are... 4345s just have greater potential and trying to fully realize it simply isn't a matter of writing a check.


Widget

[BMWCCA]

I think I'd run them single amped first to set up the L-pads, then throw the Ashly into the mix.

... 4345s just have greater potential and trying to fully realize it simply isn't a matter of writing a check.

Thanks but, due to the cc networks, I won't have the luxury of even playing the 4345s until they're bi-amped with the Ashly. No "original" passive crossover and I doubt the 2245s really want to be run full-range, or that doing so would do anything for balancing the system. I can still try the L7 trick, or 4412A, etc. Interesting idea!

Correct, I don't have measurement capability. I might have "people" who do, though. Pink-noise generator and others for EQ-ing a room for SR jobs. The guy's got a good ear and knows his system so usually the equipment doesn't get used unless it's a new room or a strange configuration. I'll bet he'd be happy to have an excuse to use it. Fred probably has the same capability.

Shielded connection cables?

[Mr. Widget]

I can still try the L7 trick, or 4412A, etc. Interesting idea!

RTA measurements are almost useless... not completely, but so much is masked... using that "trick" will speed up the process by weeks. Almost no one has ears that are good enough to really balance out a four way system using ears alone without a reference. Or spending weeks probing around in the dark.


Widget

[hjames]

pretty sure I have my Ashley-to-JBL Amp lines run with XLR-XLR cables ...
I got 6 of them after I built the new rack system
(2x 2 per amp, and 2 for Yamaha EQ to Ashley inputs)...

Why not do the same with nice shielded XLR cables?

the awkward thing is the transition from the Pramp to your Crossover ...

Thanks but, due to the cc networks, I won't have the luxury of even playing the 4345s until they're bi-amped with the Ashly. No "original" passive crossover and I doubt the 2245s really want to be run full-range, or that doing so would do anything for balancing the system. I can still try the L7 trick, or 4412A, etc. Interesting idea!

Correct, I don't have measurement capability. I might have "people" who do, though. Pink-noise generator and others for EQ-ing a room for SR jobs. The guy's got a good ear and knows his system so usually the equipment doesn't get used unless it's a new room or a strange configuration. I'll bet he'd be happy to have an excuse to use it. Fred probably has the same capability.

Shielded connection cables?

[Fred Sanford]

I'd start with coax RCA to 1/4" from Pre to X-over, and balanced XLR via twisted pair shielded from X-over to Crown modules (mic cable, not CT5, if that's what you're asking). All of that's here if you want to borrow before buying, but you probably have all or most already.

No nice RTA here, just a cheezy one. SPL meter, though. You can get white & pink noise files at whatever level you're looking for, and burn it to CD. Test tones with freq sweeps might help, too. Some useful stuff here:

http://binkster.net/extras.shtml#cd

je