Dennis Had Inspire Amps

[Musica Amantem]

Originally Posted by BearCityUSA

One other thing to consider. One thing I can vouch for is my lip-3a (upgraded from Lp-2 9 pin) is has significant additional gain than my lp-27a. More oomph with the inspire sound. If your close with the subs and such, this may be that last thing to achieve nirvana.

The main attribute of the LP-27a is its transparency. It is as if it wasn't there, especially with 56's replacing the 27's. The only way I detect some intrusion is when I compare the system's sound when going straight to the amp through the ZBit, and I believe this is so because of the balanced signal and not something stemming from the pre's design.

Having said that, what is the reason for the higher gain from the LP-3a? Is it part of the LP-3a's intended design? How transparent is it compared to the LP-27a?

[BearCityUSA]

Originally Posted by Musica Amantem

The main attribute of the LP-27a is its transparency. It is as if it wasn't there, especially with 56's replacing the 27's. The only way I detect some intrusion is when I compare the system's sound when going straight to the amp through the ZBit, and I believe this is so because of the balanced signal and not something stemming from the pre's design.



Having said that, what is the reason for the higher gain from the LP-3a? Is it part of the LP-3a's intended design? How transparent is it compared to the LP-27a?

Good question of which I only have theories. I have a suspicion that the 3a is a 27a based on different tubes but basically the same circuit. The higher gain is from the tubes themselves. 6sn7 (or 6dj8, 6cg7 in my case) has higher gain than the 27 or 56.

As to transparency, it is still very transparent. Besides the gain which is significant I have not been able to put a finger on the differences. Subtle but different. Like 6sn7 vs 6sl7 in the driver socket of an Inspire amp. Both good but I have a favorite depending on mood/genre,... The two pres live 15 miles apart and I have never a/b the two with the same setup.

[Musica Amantem]

Thanks for the info. I believe I still need to overcome the greatest hurdle via more powerful audiophile SUB(s) first.

[Musica Amantem]

Originally Posted by pstrisik

Let me know if you want more info on Rythmik configurations, particularly if you consider 8" mid-bass. Rosco has the stock dual 8" driver subs (correct me if I'm wrong on that). I have single driver 8" mid-bass with a Rythmik modified plate amp to limit how low they go and settings to blend with a sub for below 50hz. They can go above 200hz, where the regular subs will go up to something like 100. Rosco's dual 8" units may also go high while still going low. I haven't heard them and don't know how they would compare with Brian's 12" or 15" single drivers.

AVS Forum has the official Rythmik thread (Don't try to read the whole thing! More current info later in the thread):
avsforum.com/forum/113-subwoofers-bass-transducers/1214550-official-rythmik-audio-subwoofer-thread.html

I will check that thread. I visited the Rythmik site and wonder if their entry-level model could satisfy my need? After all, mine is a small listening room with a near-field setup. L12 Direct Servo subwoofer

BTW, this is what I have now: Velodyne DLS-3500R

https://www.manualslib.com/manual/38...Dls-3500r.html

[pstrisik]

Originally Posted by Musica Amantem

I will check that thread. I visited the Rythmik site and wonder if their entry-level model could satisfy my need? After all, mine is a small listening room with a near-field setup. L12 Direct Servo subwoofer

BTW, this is what I have now: Velodyne DLS-3500R

https://www.manualslib.com/manual/38...Dls-3500r.html

Velodyne has a good reputation. But I see yours is 1) a single 8", 2) ported, 3) goes down to 34Hz only, 4) low wattage amp - 175 watts IIRC, 5) sounds like you have one sub

1) 8" is a bit small for the primary sub(s). I have 12", the 8's that Rosco has are dual 8" drivers.
2) I believe a sealed sub is better for music. Theater guys like ported for the thunder bass for movie viewing.
3) I have Rythmik F12's that he specs at going down to 14Hz (it has settings to go down to 14, 20, 28).
4) The F12 is 400watts
5) Two subs make an incredible difference. If you are looking at buying a single sub, keep the Velodyne as the second sub, but a pair of good ones is worth moving towards.

If budget is at issue, I think an L12 along with your velodyne would give you marked improvement. If you can do it, go for the F12 and set sights on a second one at some point. Getting a single F12 would give you that option rather than getting an F12 as a second sub and having it with the L12.

I've not heard the L12 though. I bet it is darn good for the money. The difference between the L12 and F12 is probably relatively small and probably evident only at the higher output levels.

You will find that, if you are in the 48 states, shipping is included and he gives a 10% discount (or has) for buying two subs. That would make a pair of L12s $971. Probably the best deal around.

Post a question describing your needs on his thread. Make clear that you are interested in music as the discussion is often dominated by videophiles whose needs for bass are very different. Keep that in mind with responses you get as many of video folks will say to get a bigger one (15" or 18") and will argue that ported is just as good (Brian seems to think otherwise - ported for theater, sealed for music). I'm sure you will get some input from several that have the L12. Maybe even someone who had the L12 and moved up to the F12.

One thing that has been solid in my setup has been my pair of F12's. I've never felt the itch to change them for anything else.

[Musica Amantem]

pstrisik wrote: "If budget is at issue, I think an L12 along with your velodyne would give you marked improvement." ... "The difference between the L12 and F12 is probably relatively small and probably evident only at the higher output levels."

I'm inclined towards considering two L12's, maybe one now and another down the road. If stereo SUBs offer much better performance, and since my setup is small and I listen near-field, these L12's should do (I don't want neighbors complaining!). I just wonder how to split the PRE-out signal into both SUBs, and how to balance each SUB's different design characteristics when working in stereo. BTW, my LP-27a's SUB outs are not stereo, I understand, so how would that work?

I apologize for the nagging, Peter ... I'm really interested in this, though. Thanks!

[pstrisik]

Originally Posted by Musica Amantem

pstrisik wrote: "If budget is at issue, I think an L12 along with your velodyne would give you marked improvement." ... "The difference between the L12 and F12 is probably relatively small and probably evident only at the higher output levels."

I'm inclined towards considering two L12's, maybe one now and another down the road. If stereo SUBs offer much better performance, and since my setup is small and I listen near-field, these L12's should do (I don't want neighbors complaining!). I just wonder how to split the PRE-out signal into both SUBs, and how to balance each SUB's different design characteristics when working in stereo. BTW, my LP-27a's SUB outs are not stereo, I understand, so how would that work?

I apologize for the nagging, Peter ... I'm really interested in this, though. Thanks!

De nada!

I would still get a more informed or experienced opinion about the difference between L12 and F12, either from the forum or directly from Brian or Enrico at Rythmik.

That aside, about connecting dual subs:

1- split the preamp sub output with a quality RCA Y adapter. If you have a preamp with a mono sub output, this will give you dual mono subs. (I didn't realize Dennis was putting sub outs on any of his pre's).
2- split one pair of the preamp stereo outputs with two Y adapters. This will give you stereo subs. This would be preferable to #1 if the subs were more on par. #1 might be preferable, given how different your subs would be, so the channels are more in balance.
3- if the plate amps have speaker level inputs, you could input from each of the mains. I don't think this affects the quality of mains sound like running speaker signal into sub then out to mains would. Someone correct me if this is wrong. You would have to have one of his standard amps rather than the compact Hypex amp that normally comes with it. Don't know if you would have that option. And it is closer to #2 so may not be the way to go as long as you were mixing these different subs.

You will have to experiment to find the best settings for these two different subs. You could try any number of approaches like:
- setting bass extension on the L12 higher to be closer to the Velodyne so they were closer in what they were doing,
- keep the L12 bass extension low and crossover close to the bass extension of the Velodyne (~34Hz) so they don't overlap. This would make for seamless, but takes away some of the benefit of dual subs,
- run both crossovers at about the same setting, eg, 80Hz, with L12 bass extension low and fiddle with level controls to get the best balance in FR. This would likely emphasize lower mid-bass more than very low bass, which might be fine if not overly emphasized.

I notice that Brian changed the design of the amp controls with the compact Hypex models. I have the larger standard amp in my F12's and the more compact Hypex amp in the mid-bass units, so I am familiar with both. On the standard amp, you have separate bass extension and damping controls. On the compact amp, he combined these into one, three position switch, which reduces flexibility. This is one of the primary differences between the L12 and F12 and worth consideration. I don't know if he would offer a modified L12 with a standard amp at a cost somewhere between the two.

Sorry, gets more complicated the more we look at them!

[FloridaBoy]

Originally Posted by BearCityUSA

One other thing to consider. One thing I can vouch for is my lip-3a (upgraded from Lp-2 9 pin) is has significant additional gain than my lp-27a. More oomph with the inspire sound. If your close with the subs and such, this may be that last thing to achieve nirvana.

The mu of a 6SN7 is 20 the 27 is 9 but the gain of the LP27a may also be influenced by the 6BX7, BL7 etc. However, your upgrade may also have circuit changes. So what tube combo in the LP27a offers the most gain.

[Rosco65]

I'll add some comments to Peter's regarding Rythmik subs and Omega speakers.

Peter and I both own Omega Super Alnico Monitors. They are nominally rated at 95dB (no other specs given and I'm not asking Louis - I've asked him enough favors). They produce "good" bass in my small room (I have other Omega speakers in a larger space), but on their own are a bit thin from the midbass down. Ina small room we can play with the proximity to the wall/corner to give room gain, but may create other problems.

Peter addresses this problem using active 8" midbass drivers from 200hz to 50hz. I follow a similar approach using the off-the shelf versions from Rythmik. Peter's [prettier] custom version uses a single 8" driver driven by a 300 watt amp for each channel. Mine are dual 8" drivers in factory cabinets, driven by two 300 watt amps per side. They are available from Rythmik in the full range version I have or the midbass version Peter has. They can be crossed over as high as 200hz.

I close analog to my Omega/Rythmik system is the Salk Exotica 3. It uses the same bass arrangement I have but instead of the Omega SAM plopped on top it integrates the Seas Exotica monitor. There are extensive threads discussing the sound of this $12k speaker on another forum where Jim Salk maintains his own circle.

The Rythmik drivers used in these subwoofers and the F12G driver are designed by Danny Ritchie of GR Research. They are super lightweight drivers (hence the need for servo control) that can keep up with lightweight midrange drivers like Omega's. The L12 driver is a a paper driver but not in the same league as the F12G driver. The F12G is the same motor and frame a the aluminum-coned F12 but with Danny's lightweight driver.

The F12G driver is in a larger enclosure than the L12 driver and is not a direct retrofit. If I were choosing a sub for HT, I would cheap out and choose the L12R vented sub at $549. If I wanted stereo subs for music I would either choose stereo F12G's or stereo F8's (my preference). If you're going another route, stereo 8" subs would work just as well. I would look at crossing over higher than the usual 80hz to give a little more midbass boost.

I am about to try out an alternative midbass solution as well. Louis addresses the midbass shorfall in his "HO" models, that bring in a near-identical helper driver below 200hz, increasing the efficiency and output in the midbass, both driven from the same amp. My thought is to use a spare pair of Altec 414-8C 12" Alnico drivers (40-4,000hz) in an Altec 614 enclosure as the helper driver. I can either cut the highs to the Altec using either an air core inductor (about $200/pair - ouch!) or use a "spare" Inspire amp to driver them separately, cutting the high frequencies with an inline FMOD filter ($27.50/pair). I would expect the Altec's lightweight cone, Alnico magnet, and well-behaved rolloff to align well with the Omega Alnico driver. My LP-27a can feed both my KT88HO and KT**PSE simultaneously. The Altec is rated at 96dB vs. the 95dB of the Omega. I can tube roll to match the levels or perhaps spread the low pass crossover a bit match the output of the Omega.

Of course, this is in the queue with a number of other experiments that rely my finishing my current Honeydew list at home before I can take on new work.

[pstrisik]

Thanks Rosco, you have some knowledge about the Rythmik driver construction that I did not.

Your midbass solution is similar to mine if I read correctly. Your Altecs would be in the role that I have the 8" Rythmiks. You may get a bit better timber matching with similar magnet and sensitivity.

Any opinion about two F8's (dual 8" each) vs. two F12's (single 12" each). You evidently have 600 watts per unit to my 400. People talk about cone surface area. I imagine two 8's would be greater area than a single 12. I'd have to review my high school geometry to figure that!