Sub connection to CARY SLP-05 preamp

I think that the problem with tapping a DD sub off the main power amp is that (AFAIK) you can't use the RTA/Room EQ function that the sub offers in that configuration - unless I'm reading this wrong (always possible!) In my book, the Room EQ is probably the single best reason to use the sub in the first place (particularly with your speakers).

Incidentally, I assume that the 2 channel pre-amp indicates a music only system. In this case, I'd think that any roll off at the bottom of the sub's passband is unlikely to be very important, since there isn't a lot of music program info that low in pitch (and it can be EQ'd back, anyway, if you really want it).

If Cary says that running RCAs and XLRs concurrently is a no-no, I'd go the XLR splitter route described by Edorr.

Just my take.

Marty

If the DD works like my SMS-1 (and I'm told that it's functionally the same), there's a very versatile (fine control of slope, phase, frequency, output level) line level high cut filter to the sub. There's also a crappy, fixed 80hz, 6db/octave low cut to the mains.

The low passed line level signal undergoes ADC, and is reflected on a video screen by the RTA as a sweep tone is generated. The user then applies up to 8 bands of parametric EQ to flatten response and level match the low pass to the main signal (response is displayed up to 200hz). I can assure you guys that this is a very effective way to ensure seamless "hand-off" from main to sub.

OTOH, if you pass at high level, I assume that you keep the crappy 80hz, 6db low cut to the mains, but...

You lose all of that good high cut control for the sub. Basically, you keep the bad and lose the good - I think.

Marty

More good news: The highcut to the mains ain't great sounding either. I use a separate active NHT X2 x-over unit for rolling off the bass to the mains and take the low pass out of the X2 into the SMS for high cutting the sub. The SMS is out of the main path entirely - a good thing IMHO.

If the DD works like my SMS-1 (and I'm told that it's functionally the same), there's a very versatile (fine control of slope, phase, frequency, output level) line level high cut filter to the sub. There's also a crappy, fixed 80hz, 6db/octave low cut to the mains.

The low passed line level signal undergoes ADC, and is reflected on a video screen by the RTA as a sweep tone is generated. The user then applies up to 8 bands of parametric EQ to flatten response and level match the low pass to the main signal (response is displayed up to 200hz). I can assure you guys that this is a very effective way to ensure seamless "hand-off" from main to sub.

OTOH, if you pass at high level, I assume that you keep the crappy 80hz, 6db low cut to the mains, but...

You lose all of that good high cut control for the sub. Basically, you keep the bad and lose the good - I think.

Marty

More good news: The highcut to the mains ain't great sounding either. I use a separate active NHT X2 x-over unit for rolling off the bass to the mains and take the low pass out of the X2 into the SMS for high cutting the sub. The SMS is out of the main path entirely - a good thing IMHO.

Don't know why my post turned up twice. Strange.

You may well be right Al, I was just guessing. The speaker level may go thru the same processing, but intutively, I reached the opposite conclusion....I thought it unlikely that the speaker level signal would see anything but the high pass.

Maybe someone should put the question to Velodyne.

Marty

Edorr,

I tried a Marchand (used) from a local dealer, but the example I got was too noisy to keep. While looking around for a replacement, I tried the NHT on a money back trial basis and ended up keeping it.

Marty

Grandtech,

Are you using a video monitor to view response during the set-up tone sweeps?

If so, you can see the impact of adjusting any of those controls. As you adjust them, the change in the output of the sub will be reflected on screen. Once you see the change, you can listen for it. In my case, most changes were clearly audible, tho sometimes an adjustment that produced a visible result did not produce an audible result (that I could detect, anyway).

Fine adjustment of phase may help reduce some response anomolies prior to EQ and therefore reduce the amount of EQ you'll need to "fix" the response. Similarly, you can adjust placement of the subs while viewing response to the same end - optimal placement reduces the amount of EQ needed. That way, you'll be able to "surgically" use those 8 bands to get really smooth bass response. A mammoth PITA, but worth the effort.

The slope and level controls are essential to acheiving smoothest hand-off from main to sub. That one you will see and hear.

Marty

BTW, if the software hasn't been updated since I bought my SMS-1 (it's been +/- 3 years, so this may or may not still be true):

I would strongly advise against just using the AUTO EQ function. It does not even begin to utilize the parametric capabilities in the sub and you can do much, much better via manual adjustment w/ the video readout, per the above.

Good Luck,

Marty