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JBL_620
03-13-2014, 08:37 PM
Currently running these speakers in full-range mode plus a stand alone sub as I feel I need deeper bass while watching movies and some music so everything works great. I wanted to try bi-amping these speakers for awhile now but keep putting it off. Now I bought and received Ashley XR-2001 x-over and want to move forward quickly with this plan before I have to put this project aside again.

Here's what I have in mind regarding how everything should be hooked up:
- Use two channels of Ashly for this
- Connect XLR cables from Low Out of XR-2001 to XLR input of mono amp (x2 L and R)
- Connect TRS (Balanced? not sure here and need help here)-to-RCA cable to 2-channel amps to drive existing passive network (MF, HF, and UHF)

Here's what I will do next:
- Remove the jumpers from the speaker posts on back of the speaker cabinets
- Disconnect the subwoofer speaker wires inside cabinet from the existing passive network then connect spkr cable from the mono amp to this driver directly.
- Connect spkr wires from the 2-channel amps to existing spkr terminal to drive passive network.

Should I connect output of preamp directly to the 2-channel amp then to speaker (bypassing XR-2001) since there's already passive network for the drivers?
Or it doesn't matter to connect: pream -> XR-2001 -> 2-ch amp -> to speaker
I want to leave the LF passive network as is so I can easily convert back to stock when need be. Will this cause any issues?

Any help is much appreciated so I can hook them up correctly as the first step.

Paul

loach71
03-14-2014, 09:55 AM
Currently running these speakers in full-range mode plus a stand alone sub as I feel I need deeper bass while watching movies and some music so everything works great. I wanted to try bi-amping these speakers for awhile now but keep putting it off. Now I bought and received Ashley XR-2001 x-over and want to move forward quickly with this plan before I have to put this project aside again.

Here's what I have in mind regarding how everything should be hooked up:
- Use two channels of Ashly for this
- Connect XLR cables from Low Out of XR-2001 to XLR input of mono amp (x2 L and R)
- Connect TRS (Balanced? not sure here and need help here)-to-RCA cable to 2-channel amps to drive existing passive network (MF, HF, and UHF)

Here's what I will do next:
- Remove the jumpers from the speaker posts on back of the speaker cabinets
- Disconnect the subwoofer speaker wires inside cabinet from the existing passive network then connect spkr cable from the mono amp to this driver directly.
- Connect spkr wires from the 2-channel amps to existing spkr terminal to drive passive network.

Should I connect output of preamp directly to the 2-channel amp then to speaker (bypassing XR-2001) since there's already passive network for the drivers?
Or it doesn't matter to connect: pream -> XR-2001 -> 2-ch amp -> to speaker
I want to leave the LF passive network as is so I can easily convert back to stock when need be. Will this cause any issues?

Any help is much appreciated so I can hook them up correctly as the first step.

Paul

1) Make sure your passive crossovers are completely out of the primary part of circuit path! I assume you want to run the frequency divide from your new subs to your existing speakers with the Ashly active x-over? Driving the inputs of the Ashly from outputs of your preamp, you should connect the high pass outputs of the Ashly (80 Hz is a good divide point) to a "smallish" power amp connected to the passive x-over input terminal of your speakers. You should run the low pass portion of the Ashly's outputs to a big beefy power amp like a BGW 750 (one of my favorites). This amp should be directly connected to your passive (non-powered) subs. However, you could run your existing speakers "full range" without the Ashly's high pass capabilities managing their pass-band -- but I suspect you would notice some sonic muddiness in their low bass by doing this. Two speakers playing in the same pass-band are sometimes enigmatic.

2) Whether you run balanced or unbalanced is predicated by the capabilities of your power amps. Some do balanced, some don't. My favorite amps (older model BGW 250's and BGW 750's) will do balanced only after you replace an octal jumper on the back panel with an octal balancing transformer. In short -- read the fine manual! :D

3) When you are building this new system implementation, be sure to keep the volume low just in case you interconnected the new components improperly. Listen to each of the speakers at low level to ascertain any sonic flakiness! If it sounds wrong check the connection diagram you made (you should make one!)... Have fun experimenting -- just be cautious with the volume knob until you have verified all connections are done correctly.

JuniorJBL
03-14-2014, 12:16 PM
You would not use the Ashly because the 250 XO is just split apart when you remove the jumpers.

You will however need a gain adjustment between the 2 amps that run the LF and HF because the difference in drive levels that will be required to even out the LF and HF unless the amps are the same but even then I have found there needs to be some tweaking.

You will also need to measure them to get the output of both sections even, otherwise just use a single amp. :)

grumpy
03-14-2014, 01:23 PM
If you still want to -actively- bi-amp the 250's (without external subs) you might have a look here regarding voltage
curves (vs frequency):

http://www.audioheritage.org/vbulletin/showthread.php?21421-Biamped-L250ti-Jubilee-Clone

You could do what you initially suggested, but the electronic crossover would be in the hundreds of Hz range
(300-500Hz, nominally 400Hz in the literature between the LE14H and 2108H but you might need or want to change
it to accommodate the crossover slopes available to you with the Ashley).

Have fun. Post what you do.

JBL_620
03-14-2014, 03:41 PM
Thanks so much for all the great input so far. i need to clarify some of the suggestions though:

@loach71: Just to clarify I don't have a new sub here. I have 4-way speakers running in full-mode now (with jumpers installed on speakers input terminals) and each speaker is powered by a mono amp. Now I want to bi-amp them without external subs by isolating the LF drivers from the network. Thanks for the tip on starting out on low volume first.

@JuniorJBL:
you said "You would not use the Ashly because the 250 XO is just split apart when you remove the jumpers" Good to know this and will try it this way first.
Does this also mean I need two Y-cables to split two outputs (L/R) of preamp to feed 1) Ashly and 2) HF amp (bypassing Ashly)? Currently using XLR cables btw preamp and mono amps.From loach71's reply, looks like I don't need Y-cables just connect L/R cables from preamp to Ashly then connect four outputs from Ashly to both HF and LF amps. Will this work?


@grumpy: I will check out and read the link provided so I understand what you meant to tell me. I am a bit slow on this sort of things.


Another question for clarity, if I want to use Ashly to driver the LF speaker (with jumpers removed), I will still need to remove the driver from existing network then run amp output directly to the driver, correct?
one of the reasons I bought external x-over so I can play with it and try to plot FR curves to educate myself - just another hobby I recently got myself hooked on).

Thanks to all for the help.

JBL_620
03-14-2014, 08:02 PM
So I went ahead and hooked everything up, double checked all my connections, then powered them up and slowly increased each volume and the bass from the LF driver really put a big smile on my face. I never knew these LE14H-1 could produce this kind of solid and deep bass. At first I didn't believe it and had to double check myself again that the deep bass I felt was not coming from the M&K MX 150THX (x2 12" push-pull config) sub - sure not; the sub was disconnected.

I've been running these speakers with this sub since I bought them (3+ years ago) because I already own this sub for past 14 years.

The next step is to figure out how to properly adjust the gain levels on both HF and LF amps and x-over freq. Not even 80% sure on how to do that so more reading to do for me.
I tried to get myself setup to do this kind of things and for a start here's what I just received: 1) MiniDSP UMIK-1 mic 2) USB Sound Blaster 3) RS digital SPL 4)Win 7 laptop with REW software installed. I was able to verify I could measure a sound from the mic through REW but don't know how to interpret the FR graphs yet. Do I have proper tools to help me make the needed adjustments mentioned here?

right now, the Ashly is not in the path of the HF signal. For the LF connection, I just removed the jumpers on the back and connect output of my mono amp to the speaker terminal. I did not touch anything from the inside of the enclosure.
So something still does not look right to me regarding the connection for the LF driver. I would think that Ashly x-over signal is passing through the LF passive network to get to the driver, is this correct? Should I physically disconnect the driver from the passive network?

Thanks again for the help.

JBL_620
03-15-2014, 05:51 PM
Here's what my listening room measurement looks like now and I don't have enough knowledge to interpret what this is telling me or where I need to improve.
I set the USB mic (MiniDSP UMIK-1)at the LP which is about 15' in front of L/R speakers with the mic pointed upward at ~30 degree.

Would appreciate much if someone would explain to me what this graph means: looks Ok or looks bad? Sonically, I am happy and could be that I have no reference to compare against. I am sure a lot can be improved since I am a newbie with bi-amping and spectrum analysis, I don't believe all setting/adjustments are optimized.

Looks like my measurement only cover response range up to 800Hz only - my error in setting the upper limit in REW; for some reason REW won't accept any values above 24KHz in this case. Any idea on why this is? I will redo the measurement again to cover up to 24KHz FR range.

I set the xover freq at ~350hz on the Ashly. Thank you.

JBL_620
03-16-2014, 03:01 PM
Here's the latest room measurements i captured today with REW and FR range set correctly. Using calibrated umik-1 mic and positioned about 15' in front of the speakers. Any suggestions/feedback is much appreciated. I set the xover at ~350 Hz on Ashly.

6168361682

grumpy
03-16-2014, 04:16 PM
Now that you have a working (it appears) measurement setup, have you performed
a non-biamped baseline?

at 15ft away, you'll likely run into measuring the room as well as the speaker.

Indoors, it's tough to get much accuracy from response measurements below several hundred Hz.
That doesn't mean they aren't useful, just that they need to be interpreted to be helpful.
It can help to average measurements in a grid-like layout near where your listening position is.
In general, an in-room response that is 'flat' will sound poor; elevated bass and a slow rolloff
with increasing frequency is often preferred.

Some interesting reading:
http://seanolive.blogspot.com/2009/11/subjective-and-objective-evaluation-of.html

JBL_620
03-18-2014, 08:16 PM
The first graph has two sets of responses: 1)full range with stock passive network 2) full range with LF drivers actively bi-amped but stock passive network still intact before the LF drivers and I recorded these on weekend. The mic at LP about 15' in front of speakers.

The 2nd chart I captured today with the LF drivers actively bi-amped (bypassing LF stock passive network completely). I set the mic at about 1 meter in front each driver and turned on one driver at a time when taking measurements. I don't know how to adjust the Ashly xover yet so still trying to figure it out.

Any feedback on either graph is much appreciated. Any suggestions on what I should adjust next?

@grumpy: Thanks much for the link for reading but the info is beyond my ability to understand much of that at this stage but have bookmarked the site for future reference.


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