XPL200a amp recomendation help

[brett_s]

Hi folks,

I think I want to investigate if there is any benefit to running a bigger separate(s) amp for my XPL200a. Right now I'm running them off of my Cambridge Audio 640R receiver (rated at 120 per channel) and the common theme I here is you need more power for those speakers. I've been searching this forum to help figure out what the best amplifier, but I'm confused and I was hoping you could all share your wealth of information.

Here's the various scenarios that I have in my head, and I don't know which way to go.

1. Get a good 2 channel amplifier. If I go this route, how much power should I have and will it make a big difference in performance?

2. Passive bi-amp with a good multi channel amplifier. This way if I want to go to the active route eventually, I'll have a good starting point. Again, if I go this way, how much power and do you feel there are any benefits to this scenario over scenario 1.

3. Active bi-amp with a lower quality active crossover and the amp from scenario 2. This would be something like an Ashly XR1001 or similar quality crossover. Since you can't find a DX-1 anywhere in existence and really good crossovers are stupid expensive, my choices are limited.


For a budget, assume around $1000-$1200 total for used equipment for each scenario. So scenario 1 would be the "best" quality amp, and scenario 3 would be the lowest quality (due to having to buy amp and crossover). I hope this makes sense.

What would your thoughts be, where would you start? Brand/model recommendations are also appreciated, but not necessary. It's overwhelming to me and I need your help in figuring out the best starting point.

Thanks,
Brett

[brett_s]

No one has any thoughts on this topic?

[Titanium Dome]

No one has any thoughts on this topic?

Brett, I've been meaning to respond, but I wanted to try a few things with my pair first. I did this all just for you. :D

Answers to your inquiries:

1. I'd recommend at least 200W/ch at 8 Ohms; 300 is better. When I tried mine with a single 300W/ch Hafler, they immediately improved over the 75W/ch stereo amp I was using as a baseline. More accurately, the mids and highs improved, while the bass was just okay.

2. I used two identical 300W/ch Haflers for the passive bi-amp gig. The bottom did not improve as much as I expected, though it did improve.

3. I used the same two amps plus inserted the DX-1 back in the line, and whoom! there it is, the fantastic sound XPL200s are capable of. There's something in the active crossover that really lights a fire in the 2214H-1 driver, and it gives some stamina to the 115H-1, too. This is SO MUCH BETTER than the other two methods, it's hardly fair to compare them.

I cannot comment on the Ashley or other xover approach since I'm not a builder or devotee of crossover design. All I can tell you is that when it's done right, it's freakin' amazing.

In order of preference:
3.
1.
2.

[brett_s]

THANK YOU!:D

I can't believe you went through that work to check out the different scenarios for me. I'm amazed.

I think you just answered the question of what I need to do. I wish the DX-1 were available, as this would make it so much easier. Until then, I'll keep looking and see what I come across. Right now I'm awhile from buying anything, but you never now what happens if I stumble across the right deals! At least I know what direction I should go towards.

As for the Haflers, that's one of the ones I've been looking at (older ones). They sound like they'd be a good fit for the system.

Again, thank you for testing the scenarios.
Brett

[pasadena]

Hi Brett,

I use a NAD 208THX (250w/ch@8ohm's) amp to run the low frequency end of the 200's and I use a pair of DIY Pass Labs XA100 Monoblocks for the High Frequency, all through a DX-1. As Ti Dome stated, the DX-1 brings these babies to life but I must stress that your source, eg: receiver or pre-amp/pro also makes a big difference.

I use a Denon AVR-2805 receiver utilising the pre-outs and I have to say this is nowhere near as good by a long shot compared to the Meridian 568.2mm pre-pro I used to own. Now THAT made a huge difference. I don't get the spatial depth and sounstage with my Denon but the results are still amazing. At least I can say that I've had different products to play with and what the results brought so I know what to look for when upgrading my gear next time.

The objective is to have amps do either the High Frequency or Low Frequency sections of your speakers, not both. You'd be amazed at the results that can be achieved.

I've said this many a time but most receiver's pre-out sections just don't cut the mustard and you need to either delve into better built receivers or separates to get great results. Going down the DX-1/bi-amping path can be an expensive exercise but in this day and age, most people want the latest greatest and will offload their older gear, which can be had for a bragain. Keep your eyes opened.

Oh and BTW, MTX200 stands will also be needed to get the most out of your speakers and something JBL would have intended with these speakers. These are hard to come by, much like the DX-1's. I've been accumulating spares for my JBL gear over the years such as XPL crossovers and drivers and just recently I picked up a second DX-1 as a backup spare in case my first DX-1 dies (heaven forbid). ;)

Good luck with your project. :)

[brett_s]

Pasadena,

I've been looking for stands for the XPL200, but I haven't been able to find any. However, I am capable of fabricating some similar stands (or identical if I had actual ones in my hand that I could measure and make CAD drawings of, or JBL mechanical prints that I could fabricate from). I saw the thread you posted with lots of pictures of the stands, which is incredibly helpful, but there wasn't much for dimensions.

Would it be possible for you to take a couple of quick measurments indicating the height from the floor (front and back if there is any angle), tube size, width, length, and if there is any angle. Nothing excessive, just something quick (I don't need mounting or assembly holes). I just want the rise and angle and I'll fabricate a set up.

Even better would be if anyone had any prints from JBL, then I just could fabricate per print, but I won't hold my breath! But on this site, I'm always shocked what people have, so you never know.

As for other audio components (like dedicated pre-amps and such), I'm just slowly trying to acquire better equipment (used) as money allows. I'm sure most can understand this! In the meantime, I can enjoy what I have and improve it as I go.

Thank you for taking the time to share your thoughts, it is appreciated.

Thanks,
Brett

[grumpy]

I wish the DX-1 were available, as this would make it so much easier. Until then, I'll keep looking and see what I come across. Right now I'm awhile from buying anything, but you never now what happens if I stumble across the right deals! At least I know what direction I should go towards.

The DX-1 XPL-200 crossover implementation -appears- to be 2nd order Bessel for the
low pass and 2nd order Butterworth for the high pass... or a reasonable approximation.
So in addition to looking for equipment to preserve the signal -quality-, you might want
to check for an electronic crossover capable of such flexibility... Perhaps Marchand
could build one for you with the appropriate specs:

http://www.audioheritage.org/vbulletin/showthread.php?1908-DX-1-XPL-200-x-over-cards-on-the-way&p=16582&viewfull=1#post16582

[pasadena]

Pasadena,

Would it be possible for you to take a couple of quick measurments indicating the height from the floor (front and back if there is any angle), tube size, width, length, and if there is any angle. Nothing excessive, just something quick (I don't need mounting or assembly holes). I just want the rise and angle and I'll fabricate a set up.

Thanks,
Brett

Here's a link to some information on measurments for the stand I posted in Ti's 200 rehab thread: http://www.audioheritage.org/vbulletin/showthread.php?10065-XPL200-Rehab

There's a wealth of information about the 200's on forum, just need to look around :)

Cheers

[brett_s]

Tidome (or others),

Bi-amping seems like the way to go, but I have a general bi-amp question regarding amp size. For a single 2 ch amp setup for the xpl200's the recomendation seems to be 200-300 wpc. However, if I'm bi-amping, what would you recomend for WPC for 4 channels?

The only reason I ask, is that in theory, with active bi-amping you can use smaller amps because of the smaller frequency range it is used in. Quality amps in the 125-150 wpc range are signinfigantly less expensive then their 200-250 wpc counterparts.

If I bi-amp with two 125 wpc 2 ch amps (4 x 125) is that roughly equivalent to driving a single 2 ch amp in the 200-250wpc range (2 x 250)? Two me, this makes sense, but I've been wrong before.....

Do any of the more experienced/knowledgable members have thoughts on this?
Brett

[pasadena]

I would get a higher quality 2CH amp to drive the HF and does not generally have to be high power. The main draw will be from LF so you may want to get a higher power amp for the bottom end.

As you're splitting the services of the power requirement up for an active/bi-amp setup, the amount of power you require for each section is less required, whereas if you were driving both HF and LF, you need an amp to have enough grunt to do both.

You may get away with 100w/ch for HF and up to 200w/ch for LF. Another note worth mentioning is that the 200's may dip down to about 2.3ohm's during listening sessions, depending on what you're listening to. This may be something to factor in your decision on an amp's requirement that it is able to handle dip's down to 2 ohms stable but this is not a deal breaker. My amp can go down to 1 ohm stable and is more than enough to drive the 200's passively, let alone actively.

You probably may be need to listen to some amps and so some research on their specifications to make an informed decision.

In my situation, I have monoblocks one each side to drive the HF and one 2CH amp to drive the LF for both sides. Buying 4 amps can become an expensive exercise, most may settle with 2 amps, mine just happened to be 3 ;)

[brett_s]

Well I've acquired a couple of pieces to test and see if amp/biamp was worth the effort, similar to what Tidome did below. Although my equipment wasn't nearly as nice a what other folks use, it was a good start. I'm budget limited, so I had to start somewhere.

I picked up a 2nd generation Acurus A125x5 and an Ashly XR1001. The Acurus is two amp sections in one chasis with the front being rated at 150 wpc, and the rear being 125 wps. 3db headroom, 500 daming factor, not high end but still plenty of headroom amd woofer control for what I'm doing.

My base setup was a cambridge audio 640r receiver rated at 120 wpc on the front two. I tested a lot of higher end receivers before I bought this (Rotel, Marantz, Elite, Integra, etc) but this one was handsdown the best musically. It didn't have nearly the video features of the others, but it rocked for 2ch and the wife could still figure it out. It drove my CF150's with ease, but I don't think it was quite up to the task of the XPL200's.

Test one: set the CA640 up for preamp out on the front two channels and hooked up the Acurus in a standard 2ch setup. Dramatic difference. The bass came out and the high end softened up and the imagaing changed for the better. I thought it was pretty good before, but this was a big step forward.

Test two: hooked up the Acurus in passive biamp using the front and rear channels. Quite honestly, I didn't notice much of a difference between test one and two.

Test 3: Put the ashly in place, flipped it to biamp and stood back. holy crap! this was a quantum leap over #1. The mid and highs became even more crisp and the low end....man, it's deep, tight, and poweful. It hits hard. My wife said it sounds much better, but the bass note made her chest tight and makes her heart jump (she says it the same feeling she gets at concerts). Not muddy bass or overly loud. Just powerful. Hard for me to describe. It's cool though.

I can't believe that there is this much difference in these setups, but there is. I'm trully shocked.

I have a bunch of fine tuning to do.

I'm going to run a frequency test disc and set up a SPL meter. At least this will show me if I have any huge issues. I'd like to run an RTA, but I don't have the equipment, and can't afford to buy one.

Right now I have the crossover point set slightly under 300 hz, which is what it looked like on the DX-1 crossover chart I saw. I also have the low frequency gain slightly ahead of the high frequency as I saw this was how the DX-1 was done also.

Maybe some day I'll find a DX1 and better amps, but for right now it's a heck of a starting point.

Thank you all for the information you have shared with me, as it was appreciated.

Brett