[mjaudio]

I am on the pre-order list for the SVS AS-EQ1 and it is due to ship next week.


I just have a question which I am not sure the answer to. Since I use DIY sealed subs which I add boost to down low with my current SMS-1 how will the AS-EQ1 treat that?


I have asked before and have been told I should use a Marchand Bassis ahead of it to add an LT boost but that is $400 + $700 for the AS-EQ1 so that is quite a chunk.


I was thinking maybe a BFD1124 ahead which is only $99 and I already have but would this be advisable to boost the low end only?


I am almost to the point of just canceling my AS-EQ1 order and buying the Bassis instead to use with my current SMS-1.


Any thoughts out there?

 

[DS-21]

Does your receiver have Audyssey? You should treat it the same way as you would a receiver calibration, IMO: sculpt the low end extension to taste with whatever processor you use, and then run Audyssey. You don't want post-Audyssey processing.


The Bassis is a waste of money today, doing what can be cheaply done digitally in the analog domain and being pricey at that. Fifteen years ago, the Bassis was a great idea and inexpensive for the capability...


Another option would be to sell your SMS-1 and amp, and buy a Crown XTi-series amp, which gives you a good parametric EQ/shelving filters (for a textbook Linkwitz Transform, though I think it's more useful to take measurements in situ and adjust the EQ from there) and an amp in one box. Then run Audyssey after that.


The only reason I can think of to cancel the order would be if you have or plan on building multiple subs. Unfortunately, the Audyssey only EQ's two, which is inadequate for a modern audio system. You might want to look at the JBL BassQ, which allows a more reasonable number of subs (4 I believe).

 

[mjaudio]



Quote:
Originally Posted by DS-21 /forum/post/17001114


The Bassis is a waste of money today, doing what can be cheaply done digitally in the analog domain and being pricey at that. Fifteen years ago, the Bassis was a great idea and inexpensive for the capability...

What would be another option for an LT circuit besides the Bassis or building an actual LT?


I would be adding the boost prior to running the AS-EQ1.


The XTi amps are an option as well but I believe the one that was tested in the amp measurement thread didn't perform so well.


Right now I am only running 2 subs but plan on using 1 or 2 more in the future when I decide on what to do.


Thanks for your response.

 

[DS-21]

I think an "LT circuit" is old thinking. It was useful before doing in-room measurements was as easy and cheap as it is today. With the ability to see what a sub's actually doing in situ, it's much easier to use parametric EQ.

 

[Scott Simonian]



Quote:
Originally Posted by DS-21 /forum/post/17001484


I think an "LT circuit" is old thinking. It was useful before doing in-room measurements was as easy and cheap as it is today. With the ability to see what a sub's actually doing in situ, it's much easier to use parametric EQ.

Could you please elaborate more on this, DS-21? PEQ and LT circuits do completely different things. PEQ, for instance, does not use a shelving filter.

 

[DS-21]

How do they do different things? They both tailor the frequency response of a subwoofer! I care much less about the process than the result.

 

[Scott Simonian]

They won't have the same results, that's for sure.

 

[CZ Eddie]



Quote:
Originally Posted by DS-21 /forum/post/17001114


Does your receiver have Audyssey? You should treat it the same way as you would a receiver calibration, IMO: sculpt the low end extension to taste with whatever processor you use, and then run Audyssey. .

Unless I'm misunderstanding you, this sounds like backwards advice?

Why take the time to EQ a sub with something like a FBD, only to have Audyssey ruin whatever you just did?


I prefer to run Audyssey first. Then afterwards, I'll adjust the response to my taste using my FBD. I prefer a hard knee EQ.

Audyssey just plain sucks for subwoofers IMO. It tries for a flat, boring response. That is too lifeless for movies.

 

[mjaudio]



Quote:
Originally Posted by CZ Eddie /forum/post/17001575


Unless I'm misunderstanding you, this sounds like backwards advice?

Why take the time to EQ a sub with something like a FBD, only to have Audyssey ruin whatever you just did?


I prefer to run Audyssey first. Then afterwards, I'll adjust the response to my taste using my FBD. I prefer a hard knee EQ.

Audyssey just plain sucks for subwoofers IMO. It tries for a flat, boring response. That is too lifeless for movies.

I believe what DS-21 was referring to was in my application which is too add the boost to the low end then use the SVS AS-EQ1 to do the rest.

 

[mjaudio]



Quote:
Originally Posted by Scott Simonian /forum/post/17001528


Could you please elaborate more on this, DS-21? PEQ and LT circuits do completely different things. PEQ, for instance, does not use a shelving filter.

Is there another device that is less $$ than the Bassis that uses a shelving filter?


I do have a BFD1124 which is not being used that I could add boost to my sealed subs prior to running the SVS AS-EQ1. I have no idea if this has a shelf filter, in fact I have no idea what a shelf filter is.

 

[DS-21]



Quote:
Originally Posted by Scott Simonian /forum/post/17001555


They won't have the same results, that's for sure.

Don't be so sure. I did not get better results with an "LT" (shelving filters, in a Crown XTi2000) as I used to with parametric filters (Velo SMS-1). It just took fewer filters to get the same acoustic result with the shelving filters.


There's nothing magic about an LT.

Quote:
Originally Posted by CZ Eddie /forum/post/17001575


Unless I'm misunderstanding you, this sounds like backwards advice?

Why take the time to EQ a sub with something like a FBD, only to have Audyssey ruin whatever you just did?

Because you're not using the EQ to EQ the frequency response of the sub. (If you do things properly, i.e. multiple subs with lots of overlap in the modal region, FR will generally be fairly smooth anyway.) You're just using the EQ to tailor the subs' LF corner. What's the point of doing manual EQ of room issues when Audyssey can likely do a better job anyway?


If you're using the EQ to create a "room curve," then EQ after Audyssey, knowing that in doing so you're destroying a lot of what Audyssey does.

 

[Scott Simonian]



Quote:
Originally Posted by mjaudio /forum/post/17001621


Is there another device that is less $$ than the Bassis that uses a shelving filter?

Ssabripo uses his Behringer DEQ ($300) as a shelving filter. I don't believe the DEQ has an actual shelving filter built in but he was able to make one with a combination of filters. Probably should PM him for details on that.

The DEQ will also add a AD->DA conversion to the chain and uses XLR jacks. Could be an issue for some people. The Bassis is analog and uses RCA jacks.

 

[kgveteran]

You can't beat the ease of use. Find your subwoofers Qs. Mine are about 0.7 . Then the new Qb....0.5. Then the Fs....mine about 36hz ( kinda sad for 3 inch peak to peak monsters ). Then dial in the boost and watch the Fr extend with the twist of one old school knob.


10 minutes max !!!!!


I think i like twisting knobs hahahaha . The BASSIS is a great piece. I have to say it's.......perfect

Plus.... if you live in town as I do you can just drop in during lunch and save shipping.....and talk to Phil or his son. What a great experience !!

 

[mjaudio]

So with the Bassis if you are using multiple subs they all have to be the same, from driver to enclosure volume if you want to use for all of them.


I see they have a stereo version as well which would then let you add different LT's to 2 different subs.


I have noticed that everyone who uses them really like the Bassis so that is the main reason I brought it up.


hmmmmm, decisions

 

[kgveteran]



Quote:
Originally Posted by mjaudio /forum/post/17002486


So with the Bassis if you are using multiple subs they all have to be the same, from driver to enclosure volume if you want to use for all of them.


I see they have a stereo version as well which would then let you add different LT's to 2 different subs.


I have noticed that everyone who uses them really like the Bassis so that is the main reason I brought it up.


hmmmmm, decisions

Yes, all four subs subs are sealed, 3.0 cu. ft. each.. and co-located. You can kit build if you want and save $100.00 or so.

 

[mjaudio]



Quote:
Originally Posted by kgveteran /forum/post/17003059


Yes, all four subs subs are sealed, 3.0 cu. ft. each.. and co-located. You can kit build if you want and save $100.00 or so.

The only thing I don't understand is why they have to be co-located? I thought the Bassis was supposed to be reshaping the response in the box, not the room? If all my subs need to be co-located then the Bassis is not for me.


The Bassis kit doesn't appear to be available anymore, only the already built version.

 

[kgveteran]



Quote:
Originally Posted by mjaudio /forum/post/17004942


The only thing I don't understand is why they have to be co-located? I thought the Bassis was supposed to be reshaping the response in the box, not the room? If all my subs need to be co-located then the Bassis is not for me.


The Bassis kit doesn't appear to be available anymore, only the already built version.

Mine are co-located, you can try it any way you like. Thats all it does is extend the Fr.

 

[mynym]

DCX2496 does Linkwitz/Transform, Shelf Filters, Parametric, Delays and crossover.


3 inputs, 6 outputs..


Under $300.

 

[Vinculum]



Quote:
Originally Posted by mjaudio /forum/post/17004942


The Bassis kit doesn't appear to be available anymore, only the already built version.

Kits are still available (but not for long), if you ASK!


Dr V

 

[kgveteran]

There's more than one way to skin a cat. The BASSIS was a very unique piece of gear. It suited me quite well. You now have more choices than I had seven years ago. Just figure on what you need to get the job done.


I had no idea my subs rolled off at 36hz until I got TrueRta. There alot of things that come out when you start to measure with good solid devices.


Good luck with what ever you decide on to solve the 12db rolloff of the sealed enclosure. I still feel that sealed subs rule. After seven years i think mine are still cutting edge. They require alot of power, good solid cabinet construction, Long throw drivers and lastly "EQ" ... but the requirement of EQ isn't a design flaw, it's just the nature of the beast. Six thousand watts is a bit of over kill in my little 1800 cu ft room, but when the lights go out and the bass wicks up they never let me down.........and I never reach to lower the volume at 0db MV.....never !!!