Rp160 paired to kt120 tube amp missing some bass slam?

[DjOverdose]

Hi to every one. DJ here from Manila. I'm really happy to see that there are still forums that are really active even with the advent of FB and other social media platform. 

 

This would be my first post. Just started with Hifi this year. Probably Q1. My initial set up was a pair of Psb alpha B1 speakers powered by a hybrid tube amp with a rated 35wpc. At first they sounded OK but not until I heard the klipsch rp160. It was demoed using an emotive amp. Sorry forgot the model but it was rated like 50wpc. Moving forward, i replaced my psb and hybrid amp with the rp160 and a locally made kt120 PP UL/TR rated at 90wpc UL and 50wpc TR mode. Feels like the amp was really upto the task, the rp160 was already loud at 9 to 10 position. Don't have any problem with the highs and mids of the rp160 but I feel like it was lacking some bass slam or there are certain drum rolls or sound that becomes null. I really don't know if this was because of the amp or its the limitation of the speakers. There are some rock music that sounded dull because you can't feel the weight of the bass drum or the heavy metal feel. It's in a. Multi purpose room, like 3.4M wide and about 7M long. I love how the rp160 sound but it's kind of a let down on the drum or bass department. I hope you can shed some light on my problem. Thank you. 

[pzannucci]

Had you tried the RP160s with a different amp to understand if it is synergy between the two components that is lost?  If find that the several tube amps I had did not have slam, particularly next to the Class D amps I now use.  Also you have to look at speaker positioning with the rear ports and just plain size and set expectations appropriately.

 

If there is really no clarity in the bass vs output, I would look at the room and the amp/speaker pairing and just test another type of amp.  In my opinion, tubes are very liquid in the mids and typically image well but if I was looking for slam, bass impact, and such, I'd be looking elsewhere.  This is one of the reasons I don't move back to tubes.  It costs a lot to get everything with tubes.

[parlophone1]

I can confirm from my own experience what pzannucci says about tube amp and bass, although it seems to me that you could count in some other issues here.

 

First, you have pretty large room for that speaker. Remember that you are talking with the audience that usually is not so familiar with metric measures. 

Then it could be that you are expecting too much of bas from 160s. But they should not sound dull in any case. So try to play with speaker positioning.

 

[DjOverdose]

Pzannuci and parlophone1, 

 

Thank you for your inputs. You guys are right. Probably I was just expecting a lot from the amp considering it was a kt120 which should have ample of bass compared to other power tubes. I do understand that when it comes to bass slam or bass accuracy, that's SS territory. It's not that the speaker sounded really dull, it's just that sometimes your high up in your listening and awaiting that beat to come then suddenly you are let down by the lack of impact. Was not able to give a comparative test between my old hybrid amp and my new tube amp. Though I can say that the tube amp was really musical. Way better than the old hybrid player, but if my memory is right I find that the hybrid amp has a tighter bass. That's all there was for the hybrid amp that I can recall... 

 

There are lots of things to consider like what you guys said... Speaker position, I'm really limited on positioning the 160's at 1 foot away from the rear walls and approx. 1.5 feet away from the side wall. Distance from both speakers are like 2.5M(7-7.5ft approx)  away. Listening position is almost the same distance as the two speakers with toe in towards the listeners position. Cracking up the volume close to 11, the 160's comes alive. You can hear More details, bass extension is also good. At times it's just the attack that is missing. But I cannot find any fault in the amp and speaker combo when playing jazz, accustic, alternative music, female vocals, or any other music that is not bass slam heavy. I Also have a small psb 8" sub along side with it. But even if I cross it higher in the frequency range I still can't get the impact that I'm looking for. It's probably the limit or characteristic of the amp being it as a tube. Just really love the warm sound of the tubes. But you guys are right. They tend to be expensive for what they are. 

[tube fanatic]

Tube amps lacking bass is a popular, although totally incorrect, misconception.  I suspect that it originated because some SETs have a little less bass punch than their pentode analogues.  That said, push-pull KT-120s running in ultralinear or triode strapped should be quite capable of producing prodigious bass.  It is worth contacting your dealer to discuss this issue as it is possible that the amp is not performing correctly.

 

Maynard

[DjOverdose]

3 hours ago, tube fanatic said:

Tube amps lacking bass is a popular, although totally incorrect, misconception.  I suspect that it originated because some SETs have a little less bass punch than their pentode analogues.  That said, push-pull KT-120s running in ultralinear or triode strapped should be quite capable of producing prodigious bass.  It is worth contacting your dealer to discuss this issue as it is possible that the amp is not performing correctly.

 

Maynard 

I thought so Too... It's not like the bass is totally lacking. What I can't figure out if It's really the amp That is at fault or I was just asking too much for the monitors. Though if it would be the amp, probably making the output transformer a bit. More beefier would help. Because I'm really expecting the amp to behave a bit like an SS due to It's push-pull design and with a kt120 tubes that are known for its bass and dynamics. 

 

Probably I just need to hook these speakers to a different amp for comparison like you guys suggested. 

[dirtmudd]

3 hours ago, DjOverdose said:

I thought so Too... It's not like the bass is totally lacking. What I can't figure out if It's really the amp That is at fault or I was just asking too much for the monitors. Though if it would be the amp, probably making the output transformer a bit. More beefier would help. Because I'm really expecting the amp to behave a bit like an SS due to It's push-pull design and with a kt120 tubes that are known for its bass and dynamics. 

 

Probably I just need to hook these speakers to a different amp for comparison like you guys suggested. 

the next question is...how do you

have your speakers set up in your

room..?

[pzannucci]

On 12/15/2017 at 12:42 PM, tube fanatic said:

Tube amps lacking bass is a popular, although totally incorrect, misconception.  I suspect that it originated because some SETs have a little less bass punch than their pentode analogues.  That said, push-pull KT-120s running in ultralinear or triode strapped should be quite capable of producing prodigious bass.  It is worth contacting your dealer to discuss this issue as it is possible that the amp is not performing correctly.

 

Maynard

I would like you to show me an inexpensive tube amp that has drive in the bass and still sounds liquid in the mids/treble, particularly with around 35watts per channel?

I agree you can get some bass slam (more reasonably tubey bass) with much more expensive equipment.  The lack of definition described puts it into the tubey bass category with that style speaker.

 

 

[mike stehr]

On ‎12‎/‎15‎/‎2017 at 2:43 PM, DjOverdose said:

Probably I just need to hook these speakers to a different amp for comparison like you guys suggested

 

Does the amplifier have other speaker output connections with different impedances? Like, 4 ohm, 8 ohm, 16 ohm, etc...

[DjOverdose]

Hi. 

On 12/16/2017 at 10:15 AM, dirtmudd said:

the next question is...how do you

have your speakers set up in your

room..?

Dirtmudd, 

 

I had them like a foot away from the wall with slight toe in and probably 2.5 meters or 7ft apart from each other. 

[DjOverdose]

On 12/17/2017 at 10:29 AM, mike stehr said:

 

Does the amplifier have other speaker output connections with different impedances? Like, 4 ohm, 8 ohm, 16 ohm, etc...

It has only 2 output terminals. Both for 4 and 8ohms.

[mike stehr]

3 minutes ago, DjOverdose said:

It has only 2 output terminals. Both for 4 and 8ohms.

 

If your using the 8 ohm terminals, maybe try the 4 ohm terminals.

[DjOverdose]

8 hours ago, mike stehr said:

 

[DjOverdose]

Brought the amp and the speaker to a friend's audio shop, we sampled the gears. Was really surprised that there was a lot of bass and it ain't lacking. Though the sound was a bit thin but Soundstage was there. We tried to hook the rp160 to a 300B PSE amp 20wpc and played some samples. Bass was not far from my amp but the sound is much fuller. We have concluded that probably my amp was still relatively new.  Even if I had it for 3 or more months already. I listen to it for like 2 to 3 hours only. He told me to just use it and play some good music and wait for the capacitors and the tubes to open up. 

[parlophone1]

3 hours ago, DjOverdose said:

He told me to just use it and play some good music and wait for the capacitors and the tubes to open up. 

 

I do not know about waiting up for them to open up.

Never heard of such thing.

My tubes were working A-ok from the second they were turned on.

But then, I may be wrong...

[DjOverdose]

10 hours ago, parlophone1 said:

 

I do not know about waiting up for them to open up.

Never heard of such thing.

My tubes were working A-ok from the second they were turned on.

But then, I may be wrong...

Moo86jj7iy84t

 

Well....... For the longest time "break-in time" was a subject of a long debate. Either you belive on it or not. I guess, will just have to play along with it. Have nothing to lose but time. Time well spent listening to good music.  If after along time I still find it lacking, probably it's time for another upgrade. Like what normally happens when you thought that you had the perfect gear, but after sometime find it lacking. 

[dirtmudd]

23 hours ago, DjOverdose said:

Hi. 

Dirtmudd, 

 

I had them like a foot away from the wall with slight toe in and probably 2.5 meters or 7ft apart from each other. 

are they near the corners ?

 

so your tube amp is new ?

if new you might let break in..

for about 50-100 hours..

 

and do you let the amp warm  up

for 30-60 min...just playing low

for back ground music..befored

critcal listening ?

 

auto biasing..? or manual biasing ?

 

is it phase correct ?

 

[DjOverdose]

5 hours ago, dirtmudd said:

are they near the corners ?

 

so your tube amp is new ?

if new you might let break in..

for about 50-100 hours..

 

and do you let the amp warm  up

for 30-60 min...just playing low

for back ground music..befored

critcal listening ?

 

auto biasing..? or manual biasing ?

 

is it phase correct ?

 

Yup. They are near the corners. Probably the amp was completed around September of this year. Then around October I had them replaced the stock capacitors to mundrof Supreme. They lately changed the preamp tubes from JJ to psvane tressure. 

 

Yes I do wait for it to warm up.. Manual bias. Phase is correct. 

 

When I brought the amp to my friends shop I was really surprised that the rp160 was really putting out a lot of bass. The room where we at was sound treated, that's where I realized that I was not really lacking from bass. Even the slam was there. But after comparing it with other amp, what we noticed is that my amp was fairly sounding thinner and lacks the openess of the other tube amp that we tested. But those kt120 does really bring some big bass into the speaker. That's where I realized that just maybe the amp was still not yet properly broken In. But would be saving for an Rp280f soon... 

[pzannucci]

3 hours ago, DjOverdose said:

Yup. They are near the corners. Probably the amp was completed around September of this year. Then around October I had them replaced the stock capacitors to mundrof Supreme. They lately changed the preamp tubes from JJ to psvane tressure. 

 

Yes I do wait for it to warm up.. Manual bias. Phase is correct. 

 

When I brought the amp to my friends shop I was really surprised that the rp160 was really putting out a lot of bass. The room where we at was sound treated, that's where I realized that I was not really lacking from bass. Even the slam was there. But after comparing it with other amp, what we noticed is that my amp was fairly sounding thinner and lacks the openess of the other tube amp that we tested. But those kt120 does really bring some big bass into the speaker. That's where I realized that just maybe the amp was still not yet properly broken In. But would be saving for an Rp280f soon... 

Probably a good idea, hooked to the 4ohm taps with some resistance on the treble to provide better balance with your amp.

[JohnA]

Try changing the output impedance taps on your amplifier, if you haven't already.  The RP-160M is called "8 ohms compatible" but that likely means the impedance is well below that in the bass region, so give 4 ohms a try. 

 

Your primary room modes (resonances) are 49 Hz and 101Hz.  They reinforce each other and could very well cover up the higher bass frequencies I normally associate with "slam", above 100 Hz.  Since you cannot move your walls, easily, You might try another room, or build/buy bass traps designed to absorb 100 Hz.