Do I upgrade power or speakers to fill the room with more bass

shmoo · « **on:** 23 Dec 2008, 02:29 am »

Hi, I am running a pair of OB1 in a room around 12x10x24 with sloped ceilings. I have treated my room and have played with speaker positions.
I am driving them with a 4B SST and feel I am lacking a little bass. The mids and highs are perfect for me.
Do I want to up my power to 14b or 7b’s, or would I be better off with a pair of IB1? I can’t afford to do both.
I really like the sound characteristics of the mid/tweeter combo of the OB1 which I understand are the same as the IB1.

Phil A · « **Reply #1 on:** 23 Dec 2008, 03:38 am »

How about an integrated sub? Have you measured the frequency response at the listening position?

shmoo · « **Reply #2 on:** 23 Dec 2008, 04:14 am »

No, I never measured the freq response. I have tried a sub (a few), and it does help, though I don’t have a x-over and The frequency cut off point interferes with the high’s, I have played with different cut off points and slopes but I seem to always loose that nice transparency. Are there any subs that I should be looking at in particular that can address
This scenario? It has taken me so long to get to where I am now that each time i make the slightest of change it
usually impacts the sound in a negative way.

predrag · « **Reply #3 on:** 23 Dec 2008, 08:53 am »

I think I know what you are talking about as I owed 4B SST and OB1´s.
You have probably heard the bigger PMC´s and it can be also on pure psychological level.
OB1´s are fine loudspeakers but when you get shaked up by bigger ones things change.
IB1 and higher models have incredible bass driver (Volt) that has far bigger magnets and ability to push more air.
Bring a pair of them to your listening room before purchasing.
Listening to them for a few days will give all the answers.
Good luck!

Phil A · « **Reply #4 on:** 23 Dec 2008, 11:42 am »

Quote from: shmoo on 23 Dec 2008, 04:14 am

No, I never measured the freq response. I have tried a sub (a few), and it does help, though I don’t have a x-over and The frequency cut off point interferes with the high’s, I have played with different cut off points and slopes but I seem to always loose that nice transparency. Are there any subs that I should be looking at in particular that can address
This scenario? It has taken me so long to get to where I am now that each time i make the slightest of change it
usually impacts the sound in a negative way.

If you don't have access to a Real Time Analyzer, rivesaudio.com sells a test disc for $21 that has compensation for the Radio Shack SPL meter. I'd recommend measuring so you have an understanding of what those slight changes are doing. How about room treatments? There are places like readyacoustics.com and others that have treatments you can DIY and not spend a fortune. The room is the most overlooked audio component.

Stu Pitt · « **Reply #5 on:** 23 Dec 2008, 04:24 pm »

If all else fails, have you considered an active crossover? I don't know much about active XOs, but it seems to me like a 10B may fit the bill. I've heard them, and the results were always amazing to my ears.

shmoo · « **Reply #6 on:** 23 Dec 2008, 04:42 pm »

I have not herd anything bigger than OB1. I started off with GB1 and upgraded to
OB1’s shortly after. Unfortunately there are no dealers anywhere near where I live, (Vancouver Island) I recently saw a pair of IB1 for sale on the mainland and was Hoping to decide what to do. Either go with the bigger pair, or add more power. I understand that it’s not as simple given the Fact that room treatment/acoustics differ in each scenario.
Lets say, using 12 feet as the width of the room (speakers are placed) with the other dimensions being 12hx24long. If you were to compare these two speakers side by side using the same power, 300watts. Will there be a big difference in the amount of bass reproduction between the two? Also, Will I loose some of the imaging due to the larger cabinet and Proximity to the sidewalls?

I will consider going with a x over, that will be my next direction if larger speakers/more power are not the answer.

b5pt9 · « **Reply #7 on:** 24 Dec 2008, 12:56 am »

There is a staggering difference in bass reproduction of the IB1 versus FB1/OB1. Just look at the bass driver diameter, cabinet dimensions and power ratings. I thought my FB1's had nice bass until I bought IB1's and my jaw nearly hit the floor! Do yourself a favour and listen to those IB1's and jump on them if they're local and reasonably priced. That's my advise anyways.

electricbear · « **Reply #8 on:** 24 Dec 2008, 12:59 am »

Even if you double the power you will only get an spl increase of 3db. Power is not your answer.

predrag · « **Reply #9 on:** 24 Dec 2008, 07:59 am »

Quote from: electricbear on 24 Dec 2008, 12:59 am

Even if you double the power you will only get an spl increase of 3db. Power is not your answer.

Yes I agree: 4B SST can drive IB1 easily.
It is not a question of power, rather bass extension and placement of speakers.

ashtarul · « **Reply #10 on:** 24 Dec 2008, 08:57 am »

Speakers.

shmoo · « **Reply #11 on:** 24 Dec 2008, 03:48 pm »

Thanks for all your input. By this time next week I will have a pair of IB1's.
I will post after I set-em up and give you guyes the good news

b5pt9 · « **Reply #12 on:** 24 Dec 2008, 05:16 pm »

Nice move you won't regret it, congratulations! If you're worried about under-powering them keep in mind they are nominal 4ohms so your 4B should deliver right at the rated 500wpc. Some people have reported improvements with 14B or 7B's though.

predrag · « **Reply #13 on:** 24 Dec 2008, 09:46 pm »

I received my 7B SST2´s this afternoon.
So far they are working for some 4 hours.
First impressions compared to 4B SSTC from the first hand:
Clearly more control over louspeakers especially bass driver.
Ray Brown´s bass (Oscar Peterson trio) never sounded in my home like this.
Really sounds like a bass, not like some pocket device! Voluminous and rich.
Resolution is fantastic: one can follow each intrumentalist playing.
Soundstage is somewhat deeper than before.
Of course it is still to early to give final verdict but just to let you know my fist impressions.
P.S. No more membrane switch on the front panel. The new switch looks the same but is a normal push type.
Works better than the old one as one can clearly feel whether it is on or off.
I was very happy with 4B SSTC. However this is a little step forward but have in mind that is at twice the price of 4B SSTC.
This is seroius league whrere we are playing now!
Still compared to other contenders Bryston is moderately priced no-nonsense high technical (and sonic) value.

richidoo · « **Reply #14 on:** 24 Dec 2008, 10:49 pm »

Quote from: shmoo on 23 Dec 2008, 04:14 am

It has taken me so long to get to where I am now that each time i make the slightest of change it usually impacts the sound in a negative way.

You have strong mode at 47Hz due to divisible dimensions (12 & 24.) The mode is the reason for the big effect you hear with small changes. To fix this you need more acoustic control in the region you are hearing wimpy bass to kill the standing waves causing the null.

I have a large room and have tried 4" thick 2x4 FG panels and such in the corners but never really noticed an improvement in the bass, although that stuff worked well for upper freqs. Tact made a noticable difference in the bass (but gave me a headache) so I know there were serious bass anomolies in the room. I finally was able to scan it and saw a null of 50dB at 70Hz. Yuk.

I recently made some serious bass traps. Two boxes of 5" thick cotton bat 4 layers thick each, 2 boxes stacked 8 feet high in both corners of front wall. Thats equivalent of (16) 4" panels - and it worked! Bass came alive, cleaner and more robust in all locations of the room. Suddenly my 100W tube amps have slam and great detail. Now I have to figure out how to make it look good. Controlling bass is not easy, the physics are against you in the low frequencies. But more is more and it's still cheaper than audio gear. I got the boxes of cotton from Sensible Sound Solutions.

SynRTA is a nice program too. Play the test signal from a CD not the computer, then move your speakers/subs around in real time, watching the screen for improvement in FR. It does not need time to settle for bass readings.
http://www.libinst.com/SynRTA.htm

shmoo · « **Reply #15 on:** 3 Jan 2009, 07:50 am »

Well, I finally got hold of IB1’s today and have had a slight chance to sample and am
In complete aw. The bass is incredible, deep detailed, weighty and lots of it. In a totally different league compared to the smaller models. I most certainly got what I was looking for!
I haven’t had a chance to play much with positioning as I have only brought them home tonight.
On first impressions, the top end seems to lack the airyness and height. I am sure I will get them dialed in with some playing around. By the way I am using the standard PMC stands.
Can anyone experienced with these models provide some tips with regards to: toe in, distance from back/side wall etc.. I have the speakers positioned on the wall that’s 12feet wide.

niels · « **Reply #16 on:** 3 Jan 2009, 11:14 am »

Normally a good starting point is to divide the depth of the room with 3,5 or 7. The distance you get is the distance you should use from the front wall to the front of the baffle on your speaker. Same with the width of the room.
cardas.com, and Audio Physic has some interesting room setup suggestions, but they are nearly impossible to follow unless you have a dedicated room. Nice to try though, gives you a reference as to how free the speaker can sound, especially in the bass. Truly an eye opener, ehh, ear opener.
If you can, then try the speakers according to Audio Physics setup on the long wall also, you will get a whole different sound.
The main reason these guidelines work is that they take into account the room modes, and play along with them rather than fighting them, and of course avoid 1st reflections.
http://www.cardas.com/content.php?area=insights&content_id=26&pagestring=Room+Setup
http://www.audiophysic.com/aufstellung/index_e.html
http://www.soundstage.com/audiohell/audiohell200111.htm

jethro · « **Reply #17 on:** 3 Jan 2009, 05:43 pm »

schmoo,

What are you using for a pre-amp and source ?

shmoo · « **Reply #18 on:** 3 Jan 2009, 06:16 pm »

Jethro, I am using a BP25 with DAC option, and a Linn Ikemi CD player.

I have moved them forward and have yielded some amazing results. These speakers are
Amazing. Effortless, meaty and full sounding.
I am very happy with the results.

jethro · « **Reply #19 on:** 3 Jan 2009, 06:43 pm »

Hi schmoo,

That's pretty similar to what I am using. I'm glad the IB1's are working for you now.

To my ears the IB1's are very true to the recording and sometimes the result is not good.
I've learned to not get worried when I buy a CD that I have heard on the radio and
listen to it on my system and find that it doesn't sound very good. I may have wasted some
money but I know not to immediately check connections.

You probably already know this - did you partially fill your stands ?

I found the amount of sand in my stands made a big difference in the bass.