Unimpressive sound from Tannoy B475 subwoofer?


I impulse bought two tannoy b475 18" pro subwoofers over the weekend for what seemed like a good price.

Unfortunately, I can't seem to manage to get decent sound out of them. Did I just make a mistake and buy subs that don't perform well, or is there possibly a problem with my setup?

They want 400w-800w. I've tried a crown 800 (bridged) and a jbl synthesis 400 (bridged) and neither made them sound all that hot. The sub signal is coming from a pioneer elite, which isn't the best setup, but seems to drive my mb quart vera sub fairly nicely. The tannoy sounds much worse.

One possible issue: the crown needs a + and - for input, but the sub output is RCA, so I cut the end off a RCA cable and got the +/- from that. Perhaps bad idea?
dddrrreee
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What isn't "decent" about them?

Integrating subs is never easy and now you need to integrate two. They need to be crossed over at the proper frequency with the proper slope at the proper level and properly placed. This takes a lot of time experimenting so no wonder you haven't achieved decent sound yet.

The number one mistake people make is turning them up too loud. If they are drawing attention to themselves they are too loud.

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There are 2 different ways to connect a sub. The first is that it is powered by your own amp from which it would have a barrier strip or some other speaker connection....., and the other, it gets a signal from your preamp/Receiver, and the signal goes to the sub's own amp which includes a crossover. The RCA's are probably the input to its own built in amp. It sounds like you got the connections confused. Recheck your connections. RCA female inputs need to come from the sub/out of your receiver.
Sorry, I wasn't very precise.

If I turn off all speakers and *just* have one sub going (so there is no interference), the sound coming out of it sucks. It's just kind of muffled/chuffing and not that strong. Crossover is at 80

The music I was playing is unusual in that it is bass dominant, so in this case they should be drawing attention to themselves.

The much smaller mb quart vera sub I have (sadly discontinued) is way way better. Which is unfortunate. It's fairly precise and still strong enough to shake house foundations.

I'm hoping I'm just doing something wrong. E.g., not enough power from my home circuit?

Are the B475's viewed as good subs? I couldn't find much on the net other than tannoy seems like a respectable company.
Stringreen --- the RCA butchering was for the crown amp. It only takes speaker wire inputs (+ and -) rather than RCA connections or something along those lines.

The tannoy's use "speakon" connections.

Right now I have the subwoofer out from the pioneer receiver (an RCA connection) going to the crown amp (where I cut out the + and - wires from the RCA cable for the crown's input connections). The crown amp's outputs go to a speakon connector plugged into the tannoy.

The crossover is done at the pionner end (set to 80).

Or did I misunderstand what you meant?
What model crown 800 amp are you using? I am guessing it is an older model by your description of the input scenario. Doesn't the crown amp have a 1/4" jack input? This is what I typically see, or possibly an XLR input.

If it has the more standard 1/4" input, you can go to guitar center and get an RCA female to 1/4" male converter or just a cable that runs from male RCA to male 1/4".

Did you know these subs are not made for home use? These are like DJ speakers/subs. The purpose of these types of subs are very different than what we use subs for in the home setting (ie. they typically extend up much higher in the frequency range to 200+ hz in pro use). Also, these Tannoy Pro subs are intended to be used as part of a complete system designed for a professional type of application.

My primary concern is the connection system you seem to have rigged between the pre-out and the crown amp.

Where did you get the subs? I'd take them into Guitar center and ask them to hook them up in their sound room and play them with another pair of pro speakers to see how they sound.

Finally, listening to just the sub? I can't imagine that it sounds very good. I know once I had my Rels hooked up but my amp turned off (unknowingly) and got music just out of the Rels. It wasn't a pretty sound by themselves.
Looking at the brochure it appears Ckoffend is correct. The subs are really designed for pro use and are not powered. You could probably make them work and sound good with some work but it is much easier to integrate a Velodyne, REL etc. in your home. Velodyne and others have automatic room EQ and built in amps plus some have video outs which makes setup very easy.

http://www.tannoy.com/products/260/b475%20Brochure.pdf
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They may be pro audio but no reason they couldn't work in a home system.

I really don't understand how you have them connected so can't comment on that, but you can't really judge them by themselves. Just listening to below 80Hz is going to sound muffled and suck. How does it sound when playing the system full range?

My system if tri-amped and listening to just one band sucks but all together it sounds wonderful.

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Your right Herman if his room is large enough and doesn't care about the extra amps, crossover and not getting true deep bass. If his room is not very big it will be hard to integrate them without overpowering the room. And they also take a lot of room themselves.
But they can be made to work well in the right environment.
Wow, thanks for all the responses!

ckoffend: I'm at work, so can't check the crown model, but I believe it's a ct800b: http://www.crownaudio.com/pdf/legacy/ct800sm.pdf

It only has speaker wire inputs/outputs (they have +,-, and ground). It doesn't have 1/4.

I know the subs are pro. I was hoping for volume and not too much loss in precision. They came from SGI's theater room. The guy I bought them off of raved about them & he seemed like a very honest person. Perhaps he was not discerning about bass or perhaps (I'm hoping) I just have them hooked up wrong.

I know the overall quality of the "sound experience" of just having subs playing by themselves won't be great, but you should at least be able judge the quality of the sub output. E.g., distortion, chuffing, etc. Or am I off base?
Herman: sorry for the unclear description. Connection is:

[pioneer elite, RCA sub out] ----> [speaker wire in, crown] ----> tannoy

where the pioneer -> crown is an rca cable with the RCA connector cut off on the crown end and the two wires attached to the crown.

It didn't sound good full range, which is why I tried it alone.

In retrospect I should have gone w/ a velo or a triad, but this is what I (foolishly) pulled the trigger on so I would like to get it working if possible.

Rwwear: I have the extra amps (crowns) to drive them, so that's not a big deal. What cross over are you referring to? The pioneer receiver has a selectable crossover point, or do you mean something else?

The size of the b475s is a drawback in some sense (e.g., my gf isn't enthused) but it's kind of cool to have a couple of huge subs glowering on the sides of the room.
The Pioneer crossover should work.
Herman: sorry for the unclear description. Connection is:

[pioneer elite, RCA sub out] ----> [speaker wire in, crown] ----> tannoy

where the pioneer -> crown is an rca cable with the RCA connector cut off on the crown end and the two wires attached to the crown.

It didn't sound good full range, which is why I tried it alone.

In retrospect I should have gone w/ a velo or a triad, but this is what I (foolishly) pulled the trigger on so I would like to get it working if possible.

Problem seems much better when I make sure no stray wires from the cut RCA cable touch + to - (ugh, so stupid) and if I run a ground wire from the crown (it has +, -, gnd) to a screw on the chasis of my outlaw pre-amp.

The one thing I can't figure out is that the IOC light on the crown 800 keeps coming on, which supposedly happens when distortion goes too high.

In any case, subs are much better now. Thanks for all the replies! I don't have a reference for how these should sound, so if anyone has other ideas for improving quality, I'd be happy to try them out.

Thanks all.
A pro subs going to need a EQ system. Specially in a home. If you dont have one get one or you will never hear anything under 45HZ. Designed for ouput max volume.

Velodyne SMS1 would work.

Check your connections & loose any homade looking stray wire cables. Solder on connectors needed
I switched to using an outlaw pre-amp to send send the subwoofer output to the crown amp. The crossover is at 60hz --- you are saying even in this case the sub won't get sub 45hz? How does putting an eq system there fix this?

Thanks!
When connecting an unbalanced RCA connection to pro gear that has a balanced input, only the + and shield is used. The poor sound you heard was because you used + and -. Rewire with + and shield and it will sound much better. Also bear in mind the unbalanced output from your receiver (-10db) cannot put out the same level signal the amplifier is looking for (+4db) however it will still work if you compensate for the lost gain.
Pro subs are designed for high output but not necessarily low bass. Your sub will go down to around 28hz but you may not get that in your room. The SMS-1 will come with a setup mic to tune the sub to your room. It will have video out to see the results and allow you to adjust for your room and give you the ability to have 5 different settings plus have remote control for the volume and different modes. Velodyne's DDS series has this built in.
Iimig: dumb terminology question --- what is the shield? The crown has +, -, and ground terminals. By shield do you mean ground?

I'm only using the amp for one sub, so there is only one input -- does balanced still matter in this case?
OK, forget the second question. Doing some reading on unabalanced vs balanced...
There will be a shield and a separate ground wire in most cases but they touch and can be twisted together or not. Most balanced cables have three wires plus the shield.

Balanced still matters whether using one input or two. You may be able to run the amp in mono though.
I am connecting the outlaw 950 using a "RCA to speaker wire" cable. The RCA end is going into the outlaw. The speaker wire (+, -) is going to the crown amp (+, - respectively). Should I run the - speaker wire to both the ground and the - on the crown amp? Or do I need to get a different cable entirely?

I'm running the crown in bridged mono mode.
Oh, cool. I think I got it. I just solder the ground to the outside of the RCA connector?

When I touch a ground wire manually, the hum goes to almost nothing, so I assume that's the right approach.

Thanks for the insights!
The ground and negative wire should be attached to the grounding post of the RCA. The shield really doesn't matter as long as it doesn't touch the positive post.

Or, you could just use an XLR to RCA adapter. The best thing would be to get a balancing transformer from someone like Jensen.
08-07-11: Rwwear
Pro subs are designed for high output but not necessarily low bass. Your sub will go down to around 28hz but you may not get that in your room. The SMS-1 will come with a setup mic to tune the sub to your room. It will have video out to see the results and allow you to adjust for your room and give you the ability to have 5 different settings plus have remote control for the volume and different modes. Velodyne's DDS series has this built in

Above post was right on the money of what I was emplying with the sms-1 or any other eq. The nice thing about the sms-1 type is you get a nice grapch on your screen and some auto eq to get you started. You need to get that sub playing lower even if it costs you some max output at the 50hz and up freq responses. Home theater subs need to hit around 25hz to really get you excited about the .1 channel.
Thanks for the operational breakdown. Unfortunately, I can't tell any difference between that method and connecting an extra ground wire to the case of the pre-amp or to the RCA shield. Which matches your "really doesn't matter" point...

I was going to try a Jensen since they are "only" around $100. From their web page it seems the JT-11-BMCF would be the best bet or is that complete overkill?

http://www.jensen-transformers.com/faqs.html#faq5

The subs are great and seriously tactile at high volume with bass heavy music; I'm just hoping for something more precise at lower volumes. One improvement was from adding a sound isolating pad to separate them from the house foundation (which had various resonances that I'm sure displeased the neighbors).

But, I'm getting the feeling I perhaps should have spent the extra money to pick up some velo 18s that were for sale locally from porchecab or held out for some triad platinums...
The transformer looks like the right one.
An SMS-1 could be picked up used for around 400.00. It would help greatly.
I see a ~$400 velodyne sms-1 on amazon -- is that what you were referring to? Or do you mean JBL sms-1?

The tannoy has a tx2 system controller that came with it. Am ordering connectors to see if that makes any difference.
Argh. Sorry, missed the velo reference above somehow. Got it.

Thanks for all the suggestions!
Velodyne-SMS-1
Thanks Rwwear! Looks like I just missed the listing.

Unrelated to the original topic: I wish the audiogon software would send an email notification for subscribed threads.
I check the 'Gon every day when possible.
I picked up an outlaw 990 w/ balanced XLR outputs this w/e. After hooking this up to crown amp everything sounds much better!

It's dead quiet when no music is playing and seems noticeably louder when sound is on. (Or at least I had to turn the gain on the amp down 1/4 turn after hooking things up.)

Thanks for all the advice! Problem seems solved.

The only issue I have now is that the outlaw has one XLR out but I have two subs. I was going to use an XLR Y cable to split the signal. Is there a better approach?