[usaman]

I have these speakers and would like to reinforce the base with Frieds Model H subwoofer from an old system of mine sitting in a dark corner somewhere. It is a dual channel, transmission line woofer crossed over at 100hz from the satellites. That system is controlled by a single, 2 channel external crossover box..

I would appreciate any ideas going forward with this.  My first concern would be to determine which Xover frequency would be best and how I would tackle the sensitivity mismatch as there most probably will be?

Thanks, Frank

[JLM]

Heard the Model H in 1976.  Didn't sound anything like I was used to or what I was shopping for.  Couldn't locate the satellites until I walked right up to them.  That sound and the written information provided stuck in my head and I went back several more times that summer to absorb more.  Ended up buying the Model B's (the satellites) for my dorm and after graduation bought the coffin (subwoofer) kit.  But ended up building the Model M (separate woofer cabinets).  Alas as Bud (Fried) warned me they were too powerful for any room I could afford to put them in. 

Those crossover capacitors will need replacing after 45 years.

[usaman]

I still have the B2's collecting dust as well as 4 NOS drivers for them. They're right next to my Chartwell LS35a's and Satterberg woofers. I really need to clean house.

I never heard the M's but I sure know of their owners' raves.  I miss the coffins base: very low, robust and ever so smooth.  Bud was quoted as saying the coffin was the best da** woofer he ever built.

So, deciding what Xover freq will be most beneficial to both my Salk/Fried towers and the coffin and how to build it, is my problem at hand.

[planet10]

Best to bi-amp.

The passive was huge.

https://www.t-linespeakers.org/classics/friedH/fried_H.html

If you go REL style (letting the mains reach down untouched and the blend the woofers in) suggest something like a cheap miniDSP.

If you want to high pass the mains (usually means improved mid-top) then you likey need more effort (Nelson Pass 6-24 XO for instance).

You could pinch the passive for the woofer, but you would have to figure out how to roll off the mains.



dave

[usaman]

Youve given me a lot to think about here Dave. 
thanks for giving me your time to think this out,

I'm inclined to explore option 3 since i already have the huge coils. Maybe Dennis Murphy could lend a hand or be hired to work it out since i believe he designed the Xover.

Option 1 leaves me a bit bewildered.
Would "rel style" be akin to an active Xover's functionality whereas one preamp out goes to the miniDSP and that to the coffin subamp and the other preout to my main amp out to my main speakers?

If thats what you mean then Ive made a couple of active subs in the past and i do believe i have 1 or 2 subamps still sitting in a box somewhere.  I don't recall their amp & Xover capabilities and if they have a blend but is this what you would have me to understand?  I can take make my spare subamp module and connect it to my fried coffin cabinet, bypassing Frieds Xover of course and its signal coming from the miniDSP?

Option 2 would be possible since i have an extra 400w amp in storage. Its been a while since i read up on bi-amping with active xovers. the signal from the active Xover is sent to both amps which deliver a specific frequency bandpass to each pair?  this one specific bandpass, will be taken in by my main speakers internal Xover and processed accordingly by its own design with no sonic degradation?

[planet10]

Would "rel style" be akin to an active Xover's functionality whereas one preamp out goes to the miniDSP and that to the coffin subamp and the other preout to my main amp out to my main speakers?

Yes, then the woofer is blended in with the lows the mains oututs already.

….and i do believe i have 1 or 2 subamps still sitting in a box somewhere

Dig them out, you have a cheap experiment coming. Ideally 2 the same, but just to find out one with the woofers paralleled to get you going. miniDSP and a dedicated amp just gives more flexibility.

Option 2 would be possible since i have an extra 400w amp in storage. Its been a while since i read up on bi-amping with active xovers. the signal from the active Xover is sent to both amps which deliver a specific frequency bandpass to each pair?  this one specific bandpass, will be taken in by my main speakers internal Xover and processed accordingly by its own design with no sonic degradation?

How many of us don’t have an extra amp in the closet ;^)

Yes, that is the functionality (a miniDSP can accomplish this but i would not use the cheapest ones).

The active XO should hav elittle affect on the mains, it is after all goinf thru more electronics, but by relieving the mains from heavy lifting in the bass will improve the midrange (and the top of the mains is a single driver fullrange (what i mostly use),

Limited, but ast close to transparent as possible, would be a first order PLLXO, essentially an extra cap in fron tof the HF amplifier.

dave

[usaman]

Thanks for being so thorough Dave.

I do have a concern about the miniDSP and its signal output quality; seeing its going analog to digital and then back to analog. I guess you can't go cheap but then again, I would only want it to handle up to maybe 75hz.
There is one other super cheap way...just pull those 10lb coils out to make a quick lowpass for my coffin woofers and feed them with some zipcord coming off my main FetValve 550w amp.  No harm there but serious overlap.
Okie dokie, I'll let you know what happens, hopefully I have 2 matched subplates.