Mark, check out the following link. Many posts on this subject:
(You'll need to subscribe to the group).
They were designed using Quad ss amps. Most of us that converse on the Harbeth user group use ss amps and are quite happy.
That is true, most of us use solid state amps, and don't understand why anyone would want to use tubes. But, there are quite a few who are happy with C7's and tube amps. The amp should be fairly robust and stable. High power tube amps do fine with these speakers. The nice thing about the Harbeths is that they will reveal whatever qualities that tube amps have that you like, as long as they put out reasonable power.
thank you. Can I know, from your experience, what is the stand height which give the most bass?
The "most" bass won't be the most accurate bass. I use 16 inch stands, which are close in height to the 17 inch matching wooden stands that Harbeth used to provide with the speakers. Any lower than that and you may get more bass, but probably some lumpiness. I'd recommend 16-18 inches. Charlie and others, however, use higher stands, and seem to be happy.
To my ears, and confirmed by my in-room measurements taken from a listening position at which higher stands would make sense, the speakers sound thinner in the bass on 21 inch stands than they do on 16 inch stands.
I use, as Paul said, a 21" stand. I listen in near field and also use a subwoofer. This is an excellent combo.
Tks for your valuable advice. I have measure my stand height, and confirm they measure about 24". Is these too tall? I use that for Dynaudio 1.3Mmk2, LS3/5A , proac, Quad 11L and find okay.
Now for the Harbeth, I use Manley Mon0-block with 175W X 2 and still find the loudspeaker bass shy. Is the power rating too low? The Quad 11L which is relatively smaller, give better bass and dynamic.
I have seen many review mention highly of these loudspeakers. But i have yet understand their true strength. Now I am pretty sure the imaging is extraordinary , with very natural bass.
However, after my A-B comparison, i find the LS3/5A mid more liquid(i still own 2 pairs of Ls3/5A),with my current set-up.
Any advice welcome.
Yeah, 24 inches is too tall. The other speakers you say you put at the same height are much smaller. When you place the Compact 7's at that height, what part of the speakers do you ears line up with? They should be at tweeter level, or a little higher with the speakers tilted backward to fire directly at your ears, (don't listen to anyone who generalizes about this from his experience with other speakers). In an anechoic chamber, or in a room on 16-18 inch stands, the 7's are flat to just below 50 hz, down 6 db at 40 hz. My guess is the "better" bass you are hearing is, at least in part, an enhanced response in the upper bass which a lot of smaller speakers have to give the illusion of having better bass. The 7's don't do that. You may also be getting some cancellations from reflections off the floor or furniture. Do you have a coffee table between you and the speakers?
I have had a combination of amp and preamp that results in lower output at 50 hz and below (high preamp output impedance and low amp input impedance), but if you are not hearing that from your other speakers, then I'd guess that's probably not your problem.
Just using some telephone books, chairs, carboard boxes filled with books, anything, move the speakers down a bit, get all the furniture out of the way, and make sure when you compare speakers that you are using an spl meter to match levels exactly. If you don't think the 7's are significantly better than the other speakers you mention, then they are not the speakers for you.
I just changed to 17" tall stands and find vast improvement. The tweeters fire at my ear level now. The mid is detailed and richer; the bass is more convincing now. THANK YOU PAUL!
May i know which loudspeaker cable you are using now. I feel that the highs is a bit too much.
Mark, I'm not a big believer in the importance of cables, but the question is which cables are you using? I use an old Audioquest model, Crystal 2. It was a step up from the Indigo or Type 6, which I think you still see selling some places. It was $10 per foot retail, the same price as the Kimber 8tc at the time. I thought the Kimber was bright, an MIT cable I tried dull, and the AQ just right, but I don't trust my observations of wires.
It is more likely that you are hearing reflections off ceiling, walls, windows or hard furniture. Try experimenting with toe-in. Use a mirror to find the first reflection points off ceiling and walls and stick some soft carpet material at those spots. If you have windows, pull the drapes. Put blankets over hard furniture. Remove glass topped tables. Short of all of that, to analyze if it is the room, toe them in and listen near field to eliminate the effect of the room. If it sounds the same to you, then it's the speakers or something else in your system.
The Harbeth's tweeter has very wide dispersion, which makes the speaker sound a little toppy in live rooms. Mine sound fine in my larger room, far away from walls, with no suspended ceiling.
Glad to see you're making progress. If you are using metal stands, did you fill them? Soundbytes are good for that purpose, or unscented kitty litter from the supermarket. Just as an experiment, try uncoupling the speakers from the stand (I'm guessing you're using Bluetak or something like that), and putting a towel or some paper napkins between the speaker and the top of the stand. Sound different?
Paul always gives good advice, but he got a little ahead of himself here. He forgot to tell us that we should put the kitty litter in the freezer first.
Also, I recommend that you use the clumped kitty litter. (As a veterinarian, I have a large supply of natural clumps. In fact, I can pretreat with the sub-cryogenic necessities and ship to anyone interested, for a nominal fee.)
Now I roll my tube in the power amp and find the treble to be softer. I am quite happy with the treble now.
Paul, you are right, I am using Blu-tack in between the stand and the speakers. From your experience, how much improvement to the bass if I sand-fill the stand? Frankly i have not fill the stand or put up the spikes. What are the tweaking you do to improve the bass. I prefer to get deeper bass, and more bass if possible.
Thank you very much.
Mark, I don't think you can get more or better bass doing anything to the stand, except de-coupling the speaker from the stand by just using someting soft like a towel or a computer mouse pad might help. I doubt that filling the stand will give you more or better bass. The only reason I fill metal stands is to damp the ringing of the stand itself. Sand, or kitty litter, or if you want to spend more money, "Soundbytes" all do the job. I don't do tweaks.
Mark, down the road you might consider a subwoofer. I use an M&K MX 700 with my C7s and it gives me all the pedals on an organ beautifully. Stand tweaking is not the answer.
Charlie & Paul,
I re-positioning the harbeths and manage to get very good stereo effect as well as very natural and suficient bass. I found the Harbeths are very sensitive to the stand height in my living hall. They are far more sensitive to the stand height to other standmounter I own in my hall. I find it sound rather lean when the stand height are 3/4 inch higher with the spikes on. So i have to take out the spikes. This is against the usual hifi norm but who cares!
Now i really enjoy and understand why there are so many Harbeth die-hard fans. These are definitely keepers, so musical and natural. On comparision, I found my proAc 1SCs brighter and emphasize more on the highs in order to image well. The Harbeth image well and preserve the mid at the same time. It bring the music more lifelike, with beautiful balance.
Thank god I didn't sell them. So can I call myself Harbeth fan now, can I?
Excellent, sir. Welcome to the club. I think you may have discovered something by uncoupling those stands. It is an audiophile myth that stands are so important, but I will not waste time here defending that position. You can email me on the side if you want to hear more about speaker stands. Also explore the Harbeth smartgroups site, via harbeth.com, and I think there are archives on speaker stand issues.