Subs n Lows

[Mike Hanson]

I agree Mike. The Focals are very fast, and although it is time aligned (thanks MiniDSP), the bass notes overhang slightly on the REL. Once I sell my other speakers I'm going to try out a T7x as they are allegedly more nimble. Lets see…

I do find that very interesting, as that range of REL subs is supposed to be faster and tighter. Yet they recommended the HT/1510 for the Klipsch Cornwall IV, which is a very fast tight speaker, and the match seems to be very good.

 

[Darren]

REL HT1003 with Focal Sopra #1. Still dialling it all in with the MiniDSP Flex. Much fun, despite the sub being hugely outclassed by the mains.

Unsurprisingly outclassed. it was designed for a different application.

 

[Waxxy]

Two Totem Kin subs in use here. I have had a single REL and then a single Velodyne in the past. The REL had speed, the Velodyne had a microphone and DSP, but neither one of those blended as well as a pair of Totems. Mind you, the Totems don't go overly deep, rated to 29 hz in-room, but they fill in the bottom of a pair of Triangle Cometes very nicely. I have one place directly beside each speaker.

The Totem Kin have no remote control, but I have them hooked up to "speaker B" of my integrated amp. This allows me to turn the subs on or off with the integrated's remote. I'll turn them off once in a while to check the effect, but I always prefer the subs active.

I've also tried main speakers which go deeper in the bass than the average standpoint, but because of my listening seat being hard up against the back wall, I tend to get bloated bass. Smaller speakers combined with powered subs, allows me the flexibility to control the bass levels and avoid bloat.

 

[Mike Hanson]

Unsurprisingly outclassed. it was designed for a different application.

Yes and no. From my research, the key difference is the manner of the inputs. RELs designed for 2-channel use tend to favor speaker-level inputs, whereas the HT series have only line-level inputs (given their assumption that you'll feed it from a surround sound processor). For those who prefer the speaker level inputs, REL has their line of "Air" products that can take the speaker level (applying the character of the main amplifier), then converting it line level for HT subs.

 

[tuga]

Used to when I had 4 x ESL 57s. They were car audio based active subs and worked better than some alleged "hifi" subs. Adjustable from "undetectable backgroud level but still better than without" to full scale "stunt bass, step this way for the nightclub experience" idiocy. I now have some big 4 way cabinet TL speakers and they don't need any reinforcement.

Subs are not (just) for reinforcement or a nightclub experience.

They have the potential to improve the sound of most speakers by making the response flatter, reducing room interference which generates ringing peaks and nulls, partícula when 2 or more subs are used.
They also increase the main speakers’ max SPL capabilities reducing intermodulation and harmonic distortion when the mains are high-passed, and allow one to bypass the speakers’ ports.

 

[tuga]

Yes and no. From my research, the key difference is the manner of the inputs. RELs designed for 2-channel use tend to favor speaker-level inputs, whereas the HT series have only line-level inputs (given their assumption that you'll feed it from a surround sound processor). For those who prefer the speaker level inputs, REL has their line of "Air" products that can take the speaker level (applying the character of the main amplifier), then converting it line level for HT subs.

I don’t see any adavantage in using a hi-level connection

 

[Mike Hanson]

I don’t see any adavantage in using a hi-level connection

The argument is that the main speakers' power amplifier adds its own character to the signal. If you want your subs to blend with your mains, it's best that they also get that special sauce.

This reminds me of a test I did: I had an integrated tube amp, which made my speakers sound more enjoyable than my solid state pre and power. I wanted to test whether it was the tube's pre or power amp sections were adding this benefit.

The integrated had a pre-amp out, so I plugged my solid state power amp into that, and compared. The tube integrated still sounded far better. Later I learned that the pre-amp output wasn't going through the tubes. It was just connected in parallel to the volume wiper. So I didn't get the taste of tubes into my power amp, and the character suffered as a result.

Since then I've tried a tube pre-amp with my solid state power amp, and preferred that over the tube integrated.

So yes, there's a benefit to feeding the subwoofer with the high level outputs of your power amp.

 

[tuga]

The argument is that the main speakers' power amplifier adds its own character to the signal. If you want your subs to blend with your mains, it's best that they also get that special sauce.

I don't buy into that argument. Subs operate at frequencies where humans have very little sensitivity to sauce, smell or distortion.
Amplifiers sound different but the differences are (more) obvious in the mid and upper frequencies, unless the amplifier has high output impedance and/or is not sufficiently powerful to drive the speakers.

 

[Mike Hanson]

I don't buy into that argument. Subs operate at frequencies where humans have very little sensitivity to sauce, smell or distortion.
Amplifiers sound different but the differences are (more) obvious in the mid and upper frequencies, unless the amplifier has high output impedance and/or is not sufficiently powerful to drive the speakers.

Perhaps, yet I also know that different amplifiers produce a very different bass response from a given speaker. Perhaps that's just because they're more able to control the woofer at those lower frequencies, or perhaps it's because their characters are different, even deep down.

FWIW, I'm currently driving my REL HT/1510 using line level outputs from my pre-amp. I might eventually try their AirShip II speaker level interface, to see if there's a benefit. Then I'll know for sure.

In the meantime, I was just echoing their strategy, which they contend is worthwhile.

 

[tuga]

Perhaps, yet I also know that different amplifiers produce a very different bass response from a given speaker. Perhaps that's just because they're more able to control the woofer at those lower frequencies, or perhaps it's because their characters are different, even deep down.

But would you hear differences in amplifiers if you were listening to the subs alone? That was my point.

 

[Mike Hanson]

But would you hear differences in amplifiers if you were listening to the subs alone? That was my point.

Yes, I understand your point, and you may be correct. I don't know myself. REL says you can, and perhaps one day I'll try their AirShip II and see if it sounds different than the line level feed from my pre-amp.

 

[IWC Doppel]

I don't buy the reason about power amp character having an impact. It has no logic at all, it presumes that the sub amplifier has no character and only the power amplifier character has an influence it also assumes there is no delay or phase problem when going through the power amplifier before then going through the sub amp system and so on. I am not saying that using high level in some situations may sound better than line level but it cannot be because of the main speakers power amp quality !

Phase alignment for me is the most important to getting good integration between mains and subs

 

[Mike Hanson]

I don't buy the reason about power amp character having an impact. It has no logic at all, it presumes that the sub amplifier has no character and only the power amplifier character has an influence it also assumes there is no delay or phase problem when going through the power amplifier before then going through the sub amp system and so on. I am not saying that using high level in some situations may sound better than line level but it cannot be because of the main speakers power amp quality !

Phase alignment for me is the most important to getting good integration between mains and subs

REL is one of the most beloved manufacturers of subs for 2-channel systems, so I assume there's some validity to it. I've had lots of experience building amplifiers, setting up stereos and studios, etc., but I don't consider myself more capable than them when it comes to subs.

Regarding phase alignment, I'm also a proponent, although it's much less critical at lower frequencies, where SPLs rise and fall over much longer periods. Even so, when I've setup subs, I generally try to position them between the two speakers, lessening the possiblity of phase misalignments. If the sub needed to be placed in a more unusual location, then I would have to futz with timing more, and a DSP would become more critical.

 

[Scotchegg]

I have a little REL T/5x with my Audiovector R1 Arrete standmounts. For a long time I was kind of "anti-sub," thinking it was all just boom and thump. Then I took a punt and tried one, and I get it now. I have it set up so it just doing some subtle reinforcing to the very low end. Most of the time you wouldn't even know it's there to be honest. Then you turn it off and it's obvious what it has been doing the whole time. It's a totally different experience than what I was expecting, I still had memories of those awful PC speakers you used to get back in the day with subs that just womped about, and it was just night and day.

 

[RJohan]

That's what I thought after my first attempt, but I've done it three times by ear now, and I've been happy with the results. I have a musician's ear, an audiophile's sensibilities, and I'm very technically inclined, so I guess that combination makes it possible.

I have no reason not to believe you. But I was directing my speech to the average layman that, including myself, doesn't posses golden ears. To us mere mortals there is no substitute to measurements, I'm afraid. ( )

And as long as you haven't measured you don't know it might have been even better, do you?

 

[RJohan]

I don't buy the reason about power amp character having an impact. It has no logic at all, it presumes that the sub amplifier has no character and only the power amplifier character has an influence it also assumes there is no delay or phase problem when going through the power amplifier before then going through the sub amp system and so on. I am not saying that using high level in some situations may sound better than line level but it cannot be because of the main speakers power amp quality !

Phase alignment for me is the most important to getting good integration between mains and subs

Yes. The output from the main speakers themselves (check any distorsion measurement of speakers at low frequencies) has 'character' that vastly overshadows that from any decent amplifier driving them, so we are not 'preserving' anything useful by feeding the sub via the power amplifiers.

On the contrary, by using a proper HP filter before the amplifiers we relieve the poor main speakers of the bass they probably aren't that good at reproducing. By just adding bass from a sub we only gain half of what is possible.

 

[Colin L]

Horses for courses.

For a two or three way speaker, the bass driver will typically be crossed over anywhere between 300 and 800 Hz. Relieving the bass driver of some of the lower bass with a sub / crossover will probably have sonic advantages. My speakers (4-way) crossover to the bass driver at 100 hz and the bass system is designed to cover the bass very well so there's simply no benefit or reason to truncate the frequency range when using subs.

 

[Colin L]

Two Totem Kin subs in use here. I have had a single REL and then a single Velodyne in the past. The REL had speed, the Velodyne had a microphone and DSP, but neither one of those blended as well as a pair of Totems. Mind you, the Totems don't go overly deep, rated to 29 hz in-room, but they fill in the bottom of a pair of Triangle Cometes very nicely. I have one place directly beside each speaker.

The Totem Kin have no remote control, but I have them hooked up to "speaker B" of my integrated amp. This allows me to turn the subs on or off with the integrated's remote. I'll turn them off once in a while to check the effect, but I always prefer the subs active.

I've also tried main speakers which go deeper in the bass than the average standpoint, but because of my listening seat being hard up against the back wall, I tend to get bloated bass. Smaller speakers combined with powered subs, allows me the flexibility to control the bass levels and avoid bloat.

Waxy, you need to get those plant pots off their castors and install spikes, or even better Townshend wobbly bars

 

[camverton]

I have no reason not to believe you. But I was directing my speech to the average layman that, including myself, doesn't posses golden ears. To us mere mortals there is no substitute to measurements, I'm afraid. ( )

And as long as you haven't measured you don't know it might have been even better, do you?

Very true, only when one sets up a number of times, using measurement and ear, will one know which works best. The one proviso is that one needs to know what one’s doing to use REW and DSP crossovers effectively.

 

[camverton]

Horses for courses.

For a two or three way speaker, the bass driver will typically be crossed over anywhere between 300 and 800 Hz. Relieving the bass driver of some of the lower bass with a sub / crossover will probably have sonic advantages. My speakers (4-way) crossover to the bass driver at 100 hz and the bass system is designed to cover the bass very well so there's simply no benefit or reason to truncate the frequency range when using subs.

Yes it is horses for course although it has to be said that your speakers are no compromise and of exceptional quality. Lesser speakers will often benefit from a high pass filter. Even then choosing the best position in the room for bass, often different from the mains, means using a crossover can be more effective.