Bi amp question

[GearHead454]

I have a pair of speakers that are set up for bi amping and I have never dealt with that before.

The midrange and tweeter are driven from the primary amp and there is a crossover onboard the speakers for the tweeter to midrange transition. The woofers have their own binding posts on the speakers and there is no onboard crossover or low pass filter for the woofers.

My question is what is the typical approach to drive these woofers. I know I can drive them with subwoofer plate amps and use the crossovers on the plate amps but I am thinking about a different solution like using a stereo amp (Crown etc.) and some form of active crossover or low pass filter.

As I said I have never set up bi amped speakers so i am looking for some advice.

BTW: The speakers are new arrivals from Mister Pig's barnyard and most impressive even without the woofers running.

 

[BMWCCA]

You could try running them without a network on the woofer. Many speakers run this way and maybe the natural roll-off of the LF driver will take care of itself. If you want all the benefits of bi-amping you'll use an active crossover so that both amps only output the frequencies for their driver sets. You can use something like an Ashly XR1001 to accomplish this and play with the crossover range. Is there no indication of what these were designed to use? What speakers are they? Looks like three woofers from what I can tell. A home-brew infinite baffle?

 

[4-2-7]

You could try running them without a network on the woofer. Many speakers run this way and maybe the natural roll-off of the LF driver will take care of itself.

Try this^^ But I would want a power amp that has gain control

and ask John how he was doing it.

 

[GearHead454]

These are a custom build using Hawthorne drivers. Hawthorne Audio just last year closed shop after about 10 or 12 years of business. Each speaker has 1 Hawthorne Sterling Silver co-ax drivers (these are the middle ones) with the optional open back frame. Each speaker also has 2 Hawthorne 10" Auggie bass driver. This is what was called the "trio" setup by Hawthorne. If you are really curious here is a review from 2011: http://www.tnt-audio.com/casse/hawthorne_silver10_e.html

The crossover network is a custom build package with Alpha Core ribbon wire air core coils, Clarity capacitors, and Millls wire round resistors. The baffles are custom build by Mike Kelley and are very nice.

I just brought them home today but had a chance to listen to them at Mr Pig's place last year and they are very nice.

My understanding is that the onboard crossover is for the coaxial speakers and that my main amp connects to the binding posts for the coax driver directly (onboard crossover to handle the coax transition). The coax are driven directly from the main amp without using anything to filter out the low frequencies.

The woofers default is to have a plate amp for filtering out frequencies above 80 Hz or so and (of course) to drive the woofers.

I was considering using something like a crown XLi800 to drive the woofers which would allow me to maintain two channels (one for each speaker) but the Crown lacks the ability to remove frequencies above the 80 Hz or so where I want to transition the woofers. I guess I could just use a Harrison Lab FMod Low pass but I gather that those devices have pretty sharp cutoff.

Anyhow I am trying to explore what options I have before I just commit to plate amps.

Where does the Ashley get inserted in the signal chain? I would assume that it goes between the preamp and the poweramp and not between the poweramp and the speaker itself.

 

[GearHead454]

and ask John how he was doing it

John and I have been discussing this back and forth for a couple of weeks. He has been very helpful with different thoughts. Ultimately he was using two sub woofer plate amps which is where I may end up as well. I was just trying to make my life more complicated by exploring a different route.

 

[4-2-7]

John and I have been discussing this back and forth for a couple of weeks. He has been very helpful with different thoughts. Ultimately he was using two sub woofer plate amps which is where I may end up as well. I was just trying to make my life more complicated by exploring a different route.

He also has a long thread on them and maybe there is discussion on different setups.

 

[Poultrygeist]

Running woofers in mono vs stereo makes little difference if any.

If those woofers are 8 ohm and connected in parallel to give 4 ohms one Yung SD100 or SD200 plate amp should work. On sale the SD100 goes for under $100 and the SD200 for a little more.

I drive four 15" Eminence Alpha woofers from a single Yung SD100 plate amp with power to spare.

 

[bhunter]

John and I have been discussing this back and forth for a couple of weeks. He has been very helpful with different thoughts. Ultimately he was using two sub woofer plate amps which is where I may end up as well. I was just trying to make my life more complicated by exploring a different route.

If you want a lot of flexibility, then a MiniDSP and a power amp of your choice would be a good solution. Siegfried Linkwitz uses them for some of his designs. If you're not familiar with him here's a link to his website. BTW, I've always admired Mister Pig's Trios. Oh, with a MiniDSP, you can also do some measuring and room correction. That room in your picture looks fairly reflective.

http://www.linkwitzlab.com/

 

[GearHead454]

If you want a lot of flexibility, then a MiniDSP and a power amp of your choice would be a good solution.

Thanks for the suggestion. I guess I am looking for more flexibility as you said. The Linkwitz site is really fascinating but I don't really see that he sells the DSP and amps. He appears to engineer different speaker systems that require them. Or maybe he has DIY solutions.

Any ideas on specific amp and DSP products I should look at?

Thanks

 

[whoaru99]

Any ideas on specific amp and DSP products I should look at?

Thanks

Sorta depends how sophisticated you want to get. Many of the (relatively) inexpensive pro amps like the Crown XLS DriveCore series have built-in HPF or LPF capability. A while back I picked up a nearly mint XLS1000 on BT for like $125 shipped.

These settings are available:

The PureBand™ Crossover System provides a variable state Linkwitz-Riley 24dB/octave filter allowing you to choose a point between 50Hz and 3kHz on 1/12th octave centers. The following points are available for choice:
50Hz, 53Hz, 56Hz, 59Hz, 63Hz, 66Hz, 70Hz, 74Hz, 79Hz, 83Hz, 88Hz, 94Hz, 99Hz, 105Hz, 111Hz, 118Hz, 125Hz, 132Hz, 140Hz, 149Hz, 157Hz, 167Hz, 177Hz, 187Hz, 198Hz, 210Hz, 223Hz, 236Hz, 250Hz, 265Hz, 281Hz, 297Hz,
315Hz, 334Hz, 354Hz, 375Hz, 397Hz, 420Hz, 472Hz, 500Hz, 530Hz, 561Hz, 595Hz, 630Hz, 667Hz, 707Hz, 749Hz, 794Hz, 841Hz, 891Hz, 944Hz, 1.00kHz, 1.06kHz, 1.12kHz, 1.19kHz, 1.26kHz, 1.33kHz, 1.41kHz, 1.50kHz, 1.59kHz,
1.68kHz, 1.78kHz, 1.89kHz, 2.00kHz, 2.12kHz, 2.24kHz, 2.38kHz, 2.52kHz, 2.67kHz, 2.83kHz, 3.00kHz


MiniDSP is OK but you need to be connected to a computer for every change/setting you want to adjust. You'd need two of the 2x4 models to do a stereo triamp, or one of the higher models like 4x10(?).

Something like Behringer DCX2496 is a very powerful solution and all the changes/setting can be made right from the front panel. Also, it can do stereo triamp using just one of them.

 

[bhunter]

Thanks for the suggestion. I guess I am looking for more flexibility as you said. The Linkwitz site is really fascinating but I don't really see that he sells the DSP and amps. He appears to engineer different speaker systems that require them. Or maybe he has DIY solutions.

Any ideas on specific amp and DSP products I should look at?

Thanks

Here's the MiniDSP site:
https://www.minidsp.com/products/minidsp-in-a-box

Here's an article on subwoofer integration with the MiniDSP 2x4:
https://www.minidsp.com/applications/digital-crossovers/subwoofer-integration-with-minidsp

A lot of people use inexpensive professional amps for low frequency duty, but any power amp of adequate power will work. I've used ATIs, Adcoms, and Brystons.

BTW, did Hawthorne close up? Their site says something about coming back soon.

 

[whoaru99]

Yeah, many different amps can be used. It really all depends on the level of sophistication desired.

I mentioned the Crown mainly because it has built in LPF capability, and it also has RCA inputs so adapters or special cables aren't necessary if one isn't using balanced connections.

 

[GearHead454]

Sorta depends how sophisticated you want to get.

I think I am trying to be about as sophisticated as your suggestion. My original goal was to run the woofers on each speaker independently. That would require two subwoofer plate amps as near as I can tell. I wanted to see if there was another option that allowed the channels to remain separate and and had appropriate control of the signal to remove higher frequencies.

A small pro amp that has internal DSP sounds like what I am looking for. I will take a closer look at the Crown offerings.

The mini DSP stuff looks good as well but that means 1 more box and I think a computer to change setting.

 

[bhunter]

Yeah, many different amps can be used. It really all depends on the level of sophistication desired.

I mentioned the Crown mainly because it has built in LPF capability, and it also has RCA inputs so adapters or special cables aren't necessary if one isn't using balanced connections.

I forgot about those Crowns with the built in low pass. The Behringer is another solution albeit somewhat more expensive than a MiniDSP 2x4. I'm thinking that he'd just low pass to the two Augies and let the passive xover handle the Silver Iris. I went to Hawthorne's site, but they appear to be closed.

 

[opnly bafld]

Crown XLS 1500 works great in my biamp system, easy to integrate.

 

[GearHead454]

Yes Hawthorne Audio closed last year. A thread early this year on AudioCircle appeared to confirm that. Apparently they have a buyer for the brand and Hawthorne Audio may rise from the ashes. I hope so.

I am currently really trying to just resolve filtering the signal for low pass and powering the four woofers (Auggies). I am liking the Crown idea and am looking at options. I am not sure how many watts I need but I think my need will be at the lower end of their offerings. My primary requiremnets are:

Two independent channels - maintain stereo signal to the woofers (I know some debate as to whether this is really necessary)
variable low pass with a little finesse (to blend well with coaxial)
independent gain control for each channel (again to blend well with coaxials that are on another amp).

Thanks

 

[bhunter]

Yes Hawthorne Audio closed last year. A thread early this year on AudioCircle appeared to confirm that. Apparently they have a buyer for the brand and Hawthorne Audio may rise from the ashes. I hope so.

I am currently really trying to just resolve filtering the signal for low pass and powering the four woofers (Auggies). I am liking the Crown idea and am looking at options. I am not sure how many watts I need but I think my need will be at the lower end of their offerings. My primary requiremnets are:

Two independent channels - maintain stereo signal to the woofers (I know some debate as to whether this is really necessary)
variable low pass with a little finesse (to blend well with coaxial)
independent gain control for each channel (again to blend well with coaxials that are on another amp).

Thanks

The XLS Crowns would likely be the simplest and least expensive solution. Do you know what Mister Pig used? I assume you plan on running the coaxials full range and just low passing to the Augies?

 

[Mister Pig]

Damn thats a mighty fine looking speaker there.....I take it you have the co-ax section up and running. One day we are going to have to get you real speaker wire! Taboo subject I know.

It;s my personal opinion that a Crown XLS is probably the best long term solution for the Auggie woofers. A plate amp from Dayton, or some of the other companies are a good option for a compact solution. The crazy idea is to get something like a DBX Driverack for DSP and electronic crossover and then source a good SS amp like a B&K, Hafler Transnova, or Sumo and run the woofers with that. A bit overkill, its amazing you can eeek a bit more performance out of them that way over the plate amp. Not sure how the XLS would compare, possibly very close to that arrangement.

That is a very good speaker though, I thoroughly enjoyed owning them. Only thing is they are not well suited for a SET amp from my experience, which surprised me a bit. Took a lot of work to get them to work with my Electra Print, but it sounded fabulous with a First Watt just plopped down and connected to it.

Regards
Mister Pig

 

[GearHead454]

Yes, They are mighty fine. What speaker cables are you talking about? That's just some zip cord I scavenged off an old lamp I bought at GW as a speaker cable donor.....ha ha. just kidding. It is 12 Ga PE stuff anyhow. But seriously I thought that was a garden hose running to your new JBLs. That really wasn't speaker cable was it? It looked to be the same size as the 220v #8 copper 4 wire I have going to my stove.

I do have the coaxials running already. Right now I have them driven by my AU-717. I am also running the Rythmik F12 from the AU-717. I using the pre out/power in to get the Rythmik a signal. I set the crossover really high on the Rythmik to try to get pseudo full range between it and the coaxes.

Really sounds great already I am just getting impatient to get the 4 auggies running as well.

 

[sqlsavior]

Ahh, yes, the Quad killers!

What a joke!