Hookups like REL?

[Vedric]

Hello HSU Research,

Stay with me please this could get long :)

My system use is about 50/50 HT and 2ch music use. My main speakers are B&W N803's. While these speakers extend rather low they are not "true" full range floorstanders. In room response is flat to around 38hz.

In music reproduction I keep the signal path as pure as possible. I use the analog outs on my AH! Njoe Tjoeb cd player into my Anthem AVM-20. The anthem runs in analog bypass mode to maintain signal purity (this is impotant to me). No extra AD DA conversions but no signal directed through the sub outs either. This is my problem.

REL seems to have solved this riddle by using whats called a Neutrik Speakon connecter, though im unsure of exactly how its implemented. From what I understand the cable hooks directly from the sub to the 2ch amp that feeds the mains. The sub then uses what REL calls a, "Refined ABC® variable crossover adjustment in 24 musically correct semi-tone increments between 22Hz-96Hz". The REL allows fine enough adjustement to match well with any speakers full range capability. I dont claim to know what "musically correct semi-tone increments" means but this connection along with small enough adjustments within the REL covers 2ch playback.

The REL's also hook up to the standard LFE or SUB outs for the .1 in movie soundtracks. I dont believe the crossover in the sub has any affect on the frequency response of the .1 hookup (it shouldnt). I also dont know if both modes are active at all times, or if you have to switch between each mode of operation (hopefully they would both be active).

Ive heard the VTF-3 in a friends system and all things considered im very impressed with its performance. Although, personally Im looking for a high quality sub that will integrate into a combination HT/2ch system and cosmetics to match.

What are the chances of HSU using a system like this in future subwoofers to help bridge the "integration gap" between HT and high quality 2ch music systems? I realize this would be a price-point leap but im pretty sure HSU can compete :).

The obvious appeal of such a system is that no additional external boxes or crossovers are needed for complete HT and quality 2ch. subwoofer integration in a single "living room" system. Thanks for making it this far!

Sincerely,
Vedric

[Sasha_G]

Originally posted by Vedric
What are the chances of HSU using a system like this in future subwoofers to help bridge the "integration gap" between HT and high quality 2ch music systems? I realize this would be a price-point leap but im pretty sure HSU can compete


Thanks for the interesting question. We don't mind long questions. The answer is: we try to make our subs as flexible and easy to set up as possible, and high quality 2 channel systems are no exception. Our products are already designed to integrate with those systems.

From what you've said, you prefer to run your mains full range, without any extra electronics. So, you probably would not want to add a high pass filter to remove the bass from your mains. In that case, the VTF-3 works very well. Simply run a stereo RCA interconnect from the preamp's "pre-out" (an extra, volume controlled output on the preamp--not a "tape" output) to the VTF-3 inputs. The VTF-3's crossover should be engaged by switching it to the "IN" poisition. You will enjoy the befefits of the continuously variable crossover that can be set to any point where the mains naturally drop off. To help set the crossover and levels, we supply a test CD with our subs. The sub will handle bass, and your mains will run full range down to the point where their frequency response naturally ends.

If you want to add a high pass filter to the mains to curtail their bass and ease the strain on their amp, then our 500 Watt amp with a TN Series sub would be the best bet. It has both high and low pass fitlers built in. You can also use our "High Pass Box" with the VTF Series.

By the way, our high pass systems use only the minimum of high quality resitors. Our crossovers are continuously variable without increments. Our crossovers have an extra steep, 24 dB per Octave slope at all freqencies. Some other companies use 12 dB per octave which can lead to poor integration. Others advertise 24 dB per octave, but their slopes actually become 12 dB or worse when you turn them to lower frequencies. We use a more expensive stacked potentiometer design in the amp so that the bass gets out of the way quicker at lower frequencies. This is not something we advertise much, just another quality feature that people should expect.

Sasha

[Vedric]

Sasha thx for the reply. I have a another question though.

Sending a full range signal to the sub with pre-outs is fine. This would indeed allow me to bring the sub in underneath my mains for 2 channel. Correct me if im wrong but would this cut off the frequency response of DD or DTS .1 channel playback (sub out). Usually this channel, depending on the soundtrack, operates from 120hz and down or 80hz and down. If the crossover also affects the frequency range of the .1 (sub out) signal this solution wont work.

thx, Vedric

[Sasha_G]

There is a way to use the sub for both music and home theater with such a setup. Dr. Hsu suggests using a Radioshack switch box between the preamp processor and the subwoofer. The subwoofer is always connected to the switch box, but the source is switchable between the pre-out and the subwoofer signals coming from the Preamp-processor.

In this setup, you first adjust the volume and crossover on the subwoofer for the music setting-- when the source signal is coming from the pre-outs.

When using the Anthem in surround sound mode, there are two steps you must always take:
1) Switch the switch box to the source coming from the surround processor's "subwoofer output".
2) Flip the crossover on the subwoofer to "OUT". Since the LFE has a signal up to 120 Hz, disengaging the crossover is necessary.

On the Anthem, you should then set the mains to "SMALL" and set the crossover to a low setting, preferably 80 Hz. Then adjust the subwoofer level on the Anthem, turning it up or down. Many people prefer the subwoofer turned up during home theater, and this setup lets you adjust the levels once, and only once. When the system is in music mode, the subwoofer has a crossover frequency that matches the mains natural dropoff, and a subwoofer level to match the mains. When in home theater mode, the crossover is handled by the processor and the sub's level can be elevated or lowered as desired on the processor. Let me know if you were not clear on any of this.

Sasha

[Vedric]

Yea thats what I figured. Adding yet more boxes to the system is something I would rather avoid. This system is in my main living room so keeping the clutter to a minimum is preffered.

I guess this means HSU wont be looking into such a setup for future subs? I am curious if Dr. Hsu is familiar with how the REL's hookup and operate. I would be interested in his comments about it. It just seems like such a simple solution and wouldnt be difficult to include in future packages. Oh well I tried! Thanks for your time Sasha.

Sincerely,
Vedric

[Dr_Hsu]

The VTF-3 would work properly with both speaker level and line level inputs hooked up at the same time. Speaker level input sensitivity may be a tad lower with the line level input hooked up and left on, so I would suggest hooking the LFE output to both line level inputs to make sure both channels are the same. You do want to switch the crossover to out for HT applications and in for two channel music.

My biased opinion is that the REL approach does not make any sense. When you are running the main speakers full range, what you want to do is to bring in the subwoofer where the main speakers fades out. Hence you have the best control by having it continuously variable rather than discrete steps.

[Lwang]

My biased opinion is that the REL approach does not make any sense. When you are running the main speakers full range, what you want to do is to bring in the subwoofer where the main speakers fades out. Hence you have the best control by having it continuously variable rather than discrete steps.

But with the Rels, you could adjust the xo freq accurately in increments of a couple of hertz, something that is impossible with the continuously adjustable xo, which is wildly inaccurate in the first place.

That is not to say the Rel is better, since one would still have to measure where the main speakers rolls off, adjust the xo of the sub and measure where it rolls off, and then measure the combined output when both the main speaker and sub are playing. You can't just find out the -3dB point of the speaker from the spec and dial that freq on the sub.

[Dr_Hsu]

The actual frequency in relation to the readout may be off, but it is a continuously variable crossover, which means even finer adjustment than 2 Hz steps, for example. I do not mean to dial in a number on the frequency control that correspond to the rated cutoff of the main speakers. What I mean is to use a SPL meter to adjust for the smoothest response. You will be able to fine tune to a better degree than with a discrete step one. The same principal applies to the volume control. A continuously variable control allows you to adjust more accurately than a volume control that goes in 2 dB steps. It does not matter that the volume control is not truly linear (since its a single channel). Note that depending on the room effects, the actual frequency you want to bring in the sub may be very different from the rated cutoff of your main speakers.

Its a different story if you have both a high pass and a low pass that you want to match. In this case, we are trying to have a subwoofer blend in with a main speaker that is running full range.

[Sasha_G]

Originally posted by Dr_Hsu
I do not mean to dial in a number on the frequency control that correspond to the rated cutoff of the main speakers. What I mean is to use a SPL meter to adjust for the smoothest response.

This seems like an important point both Dr. Hsu and Mr. Wang are making. One can't simply rely on the rated frequency response of a speaker and set the subwoofer's crossover to that frequency. A little old fashioned empirical observation is nessesary. :)

For many this only involves listening to a linear frequency sweep of bass that goes accross the crossover point and roughly setting the crossover and volume on the sub to match the mains.

If there is a bass "hump" in the middle of the sweep, the overlap of bass should be removed by turning down the subwoofer's crossover. If the lowest bass notes are too loud, the the volume on the sub should be turned down. If there is missing bass, the crossover should be turned up. The last two tracks of the test cd included with our subwoofers are linear sweeps of bass that can be used for this. This is not really an accurate method, but is better than nothing.

For a better setup we strongly recommend the radioshack SPL meter method.

[Vedric]

Dr. Hsu I think the main selling point on the REL is the speaker level connection actually hooks up to the amp. This retains the same base colorations of the amplifier between the mains and sub. Though I agree with you about the xo. Continuously adjustable, even if the numbers by the knob are wrong, could provide smoother integration.

Other selling points are both the high level and low level connections have balanced inputs (Neutrik high level and XLR low level) along with a seperate volume control for each. No external switch or xo boxes would be needed at all (very important to me). Though from your previous post it sounds as if the VTF-3 would not require any external boxes, correct me if im wrong on this.

For me, the wood veneer finish is a very strong selling point. Natural cherry finish would match perfectly with my B&W's. I appreciate what HSU is doing with the rosewood finish and im sure people with other rosewood looking things will be pleased. That said, I would take piano black finish before rosewood in my living room.

I know the REL's sound good but price vs. performance are no match for HSU's. Looking at output and extension alone the VTF-3 is in the same class as the REL Stadium III which is nearly 4 times the price. Though much of the cost is justified, some is not (imported and prestige in the name).

I keep wondering what HSU could offer for the same price. Even at a 2k price point. Time isnt on my side though. Im using a 12 year old NHT subwoofer. It doesnt seem to extend any lower than my Nautilus 803's.

Thx for the discussion.
Vedric

[Sasha_G]

Originally posted by Vedric
...I think the main selling point on the REL is the speaker level connection actually hooks up to the amp.
...


With the addition of your own high quality speaker cable, all of our amps will hook up directly to the main speaker amp to carry the "sonic signature" of the amp. In our case, you may use your own speaker cable. If you use banana plugs with the 250 Watt amp or VTF-3 amp, there is an additional benefit from the spring tension of the connector, which increases reliability over other types of connectors such as bare wire.

We don't prefer this method of speaker level input over line level input, because it creates more chances of a reduction in sound quality. The sonic signature of the amp includes the distortion it creates. Plus, if your amp ever clips, the subwoofer will sound like it clips as well. There is not a big difference in sound quality between the two methods,as long as your amp doens't clip.

Originally posted by Vedric

Other selling points are both the high level and low level connections have balanced inputs (Neutrik high level and XLR low level) along with a seperate volume control for each. No external switch or xo boxes would be needed at all (very important to me).

Point taken. We don't offer these features.

Originally posted by Vedric
I keep wondering what HSU could offer for the same price.

Well, you could get two VTF-3s or two TN Series subs with a 500 watt amp. Our Rosewood VTF-3 will be out in June. I hope you have the time to wait until then.

[Gene H]

I'm considering the VTF2, will it work properly if I hookup both the speaker level from my amp for music and the sub preamp out for movies?

Music (using the sub's crossover):
- mains get full signal from amp
- sub gets full signal from amp
- sub gets no signal from sub preout

That's seems fine.

Movies (using the receiver's crossover):
- mains get high-passed signal from amp
- sub gets same high-passed signal from amp
- sub gets low-passed signal from sub preout

How does the sub resolve the dual signals in this case? If it defaults to only the line level sub preout, that works. If it uses only the speaker level signal, bass would be lost. If it sums the two, mids and highs seep into the sub's output.

Help!

[Sasha_G]

The VTF-2 sums the two signals, so if your receiver does not turn off the subwoofer-out when in source passthrough mode, there will indeed by unwanted effects in this situation. The source passthrough mode on receivers is for those who want to do high end digital processing seperately, who have a seperate high end and low end audio system to integrate, or who use a DVD audio source without using surround processing.

Unfortunately, as far as I know, most receivers do NOT turn off the subwoofer-out when in passthrough mode. That is, they keep on doing a digital bass management on the subwoofer out channel even though it is in passthrough mode.

In these situations, for people who DON'T want the receiver doing digital manipulation in source passthrough mode, we recommend using a switchbox that switches between the line level subwoofer-out and line level pre-out for most receivers. This was described above in my previous post in this thread.

To briefly recap, the Receiver sends the subwoofer-out and preamp-out signals to a radioshack line level switchbox. The switchbox sends one signal to the subwoofer. The subs crossover has to be turned to the "IN" position for music passthrough and "OUT" for receiving the subwoofer channel from surround sound.

We could add a switch to our subwoofers, but it wouldn't offer much of an improvement in sound quality over an external RadioShack switch. Since the switchbox is just switching the bass, it does not effect the more delicate sounds that are going to the mains. Switchboxes don't have as big as effect on bass as they might on the signal going to the mains.

Futher, people with DVD-Audio usually have 6 seperate channels of audio that ALL need bass management, and this kind of switching would probably add unwanted expense on a subwoofer for a feature that under 20% of our users use. We would need to have 6 inputs with seperate crossovers on each channel, plus the input for the LFE subwoofer-out on the receiver, plus a switch to switch between two modes. This would be better handled by a seperate bass management component.