Picked Up a Pair of ADS L1230 ... Curious about the Bi-Amp "Option"

[e30m3mon]

I've been amassing a bunch of speakers over the past several years, Ortofon 445, 335, ADS L990, L9e, L620, and now L1230. Yes, I have a problem, but I have come to appreciate how the WOPL 400-II sounds SO DAMN GOOD, no matter what I throw at it. Pretty much all speakers have needed some kind of hand-tending when I took ownership; re-foaming the cones of nearly all woofers and sourcing drivers, or sending the ADS parts to the amazing Richard So.

I need to thank @J!m for bringing forward a CL ad for the L1230s recently. These are in remarkable condition, but some elements will need some freshening by "Dr. So".

These speakers have connections for standard/full range connections as well as the (switched) option to run in bi-amped configuration where the two woofers are driven separately from the midrange/tweeter pair. According to the instructions ADS had a crossover system, C2000, for the Lxx30 series...and naturally it is nearly impossible to find. I am thinking to try a MiniDSP as an active crossover, but curious about amplifier selection to drive the high and low sections. I have the WOPL 400-II, as well as a Carver MXR130 and a MXR150 that were put into storage by the WOPL 400-II.

At this point I am more curious about bi-amplification, because the binding posts on the back of the L1230s have piqued my interest. Thoughts and reflections from anybody who has gone down this path ... worthwhile or too much of a hassle for what is gained from bi-amping? Are either of those Carver amps even worth considering or just leave them collecting dust? Setting up the MiniDSP would likely be a challenge onto itself, as I have no experience with figuring out the crossover sweet-spots. According to Richard, the L1230 crossover point is 655Hz with the C2000, but I don't know what the slope rate is and type of crossover (Linkwitz/Riley, or other etc).

Any insight would be appreciated
Thanks!

 

[AngrySailor]

I run both my systems bi-amped (house and shop). The shop system uses 4 amplifiers, two for mono subs and separate left and right amplifiers for the stereo 3 way passive crossover cabinets. It’s technically a 4 way system. Basically the same in the house with a big carver Pt-2400 powering subs ~60-70hz and down with a PL700/1 powering three way passive cabinets for my stereo highs. Both sets of passive cabinets have custom modded eminence crossover with crossover points of 500/3.5khz. The woofers run from the active crossover frequency (24dB/oct slope) up too 500hz on the passive which has 12dB/oct then the mids take over to 3.5khz and the tweeters are rolled off at 18dB/oct all passively except for the low low cut off of the active unit. It does free up TONS of power for the sub woofer amp as it’s not amplifying frequencies that you then filter passively. If your speakers don’t have good low response, it may not be worth it. At the very least you should run a steep high pass filter set slightly below your speakers low frequency roll off. That alone will help with wasted power and uncontrolled cone movements. If the speakers have deep low response and can handle more power, bi amping surely will help. That said, there may be some sound qualities which improve at lower levels due to frequency separation in the amps, there is also decent flexibility with level controls to contour the low end, especially find its this useful when playing from different sources/mixes. If I need a little more or less bottom it’s one knob to add or remove level below my crossover point. Very easy to dial in the sound I want.

 

[J!m]

Glad to hear those speakers worked out for you!

Much better than my last purchase, certainly.

 

[e30m3mon]

Thanks Andrew - I will need to get a better understanding of crossovers before I try to understand most of your post!

I must admit the bass response of these speakers have amazed me. Prior to buying these, I have been using an AudioControl Richter Scale electronic crossover with the default (comes from the factory - but can be changed to any desired frequency by plugging resistor packs) 90Hz crossover to the mono subwoofer. My sub is a dual-voice coil 10" in a 1.5CuFt sealed box. It rattles the walls to the point where my wife calls me in the man cave 75' from the house to turn it down! I have found the L1230s sound pretty good without the sub - possibly because the 90Hz crossover is not correct for this configuration. Again, I have not experimented with the setup.
Al

 

[AngrySailor]

Thanks Andrew - I will need to get a better understanding of crossovers before I try to understand most of your post!

I must admit the bass response of these speakers have amazed me. Prior to buying these, I have been using an AudioControl Richter Scale electronic crossover with the default (comes from the factory - but can be changed to any desired frequency by plugging resistor packs) 90Hz crossover to the mono subwoofer. My sub is a dual-voice coil 10" in a 1.5CuFt sealed box. It rattles the walls to the point where my wife calls me in the man cave 75' from the house to turn it down! I have found the L1230s sound pretty good without the sub - possibly because the 90Hz crossover is not correct for this configuration. Again, I have not experimented with the setup.
Al

That 90hz is a reasonable crossover frequency especially for a 10” sub. I find my 18’s get a little “boomy” sounding if I bump them up from 60-70hz towards 100hz. Every speaker will have a different response so there’s no “fixed” crossover point, it’s either by measurements for a flat response or by ear as to what sounds good. I’m in the “by ear” camp when it comes to contouring my sound... I do build the speakers to be reasonably balanced but don’t hesitate to use some EQ and level control to make it sound right in my room and to
My ears.

 

[NeverSatisfied]

That 90hz is a reasonable crossover frequency especially for a 10” sub. I find my 18’s get a little “boomy” sounding if I bump them up from 60-70hz towards 100hz. Every speaker will have a different response so there’s no “fixed” crossover point, it’s either by measurements for a flat response or by ear as to what sounds good. I’m in the “by ear” camp when it comes to contouring my sound... I do build the speakers to be reasonably balanced but don’t hesitate to use some EQ and level control to make it sound right in my room and to
My ears.

Amen

 

[e30m3mon]

That 90hz is a reasonable crossover frequency especially for a 10” sub. I find my 18’s get a little “boomy” sounding if I bump them up from 60-70hz towards 100hz. Every speaker will have a different response so there’s no “fixed” crossover point, it’s either by measurements for a flat response or by ear as to what sounds good. I’m in the “by ear” camp when it comes to contouring my sound... I do build the speakers to be reasonably balanced but don’t hesitate to use some EQ and level control to make it sound right in my room and to
My ears.

Agree with your "by ear camp" comment as I still have enough hearing left (despite all the bands I played in and did sound for in my younger days!) to decide whether something sounds right or not.

Not sure if you're familiar with the AudioControl Richter Scale, but it comes with a precise microphone that is used in conjunction with a warble tone generator and RTA for low-end frequency tuning. I also have the complimentary AC C101 equalizer with RTA and similar microphone that I can use to observe what flatness might "look" like - but in regular usage, I try not to use any EQ, as I always end up with smiley faced sliders, where the RTA results in the sliders positioned in odd locations.

I'm going to pull the trigger on the MiniDSP 2x4 and give that a try. The 2x4HD looks to have a lot more function, but I'm not sure I need all the functionality and cost for my testing.
Thanks again for your input, Andrew.
Al